UNITED STATES DEPARTMENT OF THE INTERIOR 

Ray Lyman Wilbur, Secretary

GEOLOGICAL SURVEY 

W. C. Mendenhall, Director

Professional Paper 167

LOWER TRIASSIC AMMONOIDS OF NORTH AMERICA

BY

JAMES PERRIN SMITH

UNITED STATES

GOVERNMENT PRINTING OFFICE 

WASHINGTON : 1932

For sale by the Superintendent of Documents, Washington, D. C. Price 70 cents

CONTENTS

Page

Introduction ___ __-_______.___.___________________________________-___-_____-_--______-_-_---__-_-_----_-_---_ 1

Bibliography._____-_____________--_-------_-_----________-----__--___-_-------_____---__--__----_----------- 4

General features of the Lower Triassic ammonoid fauna_-___-_---_-----_------------__-_----_--------------------- 6

Lower Triassic faunal zones of North America._______________-____________-_________________---_---_--_-_-_--_-_ 7

Meekoceras zone of Idaho__.-_----------------------------------------------------------------------------- 7

Meekoceras /one of California ____-_-_____-__-_,___________-_______-__-___________-_____---___-----_--_---.. 9

Meekoceras zone of Phelan ranch, Elko County, Nev_.__-__-_-_-_-_------------_____--_-_--_-_----------.----- 9

Fauna of Owenites subzone of southeastern Idaho.,___________________________________________________________ 10

Fauna of Anasibirites subzone of Utah ________..__________---_____--__-_-----_-___-_-_---_----------------_ 10

Tirolites zone.__-__________------__--_-----_--________----_-_----------_-_-___-_--__--------------------- 10

Columbites zone.___________--__---_--_---_____________-_-----_---_---___----__-_---_------__------------- 11

Lower Triassic interregional correlation zones.____-__-____-____------_-_-_-_-_-_-_-___-_-__---_--_-----------_-_- 1-1

Historical summary..._____._-_-____-_______-_-________--_-_-_-_-__-_--__-_-_______-________-_--___-_-____ 11

Geographic distribution of Lower Triassic interregional zones-____--_--___--_---________-_-____-__-_-_--_-___-_ 13

General characters of the Lower Triassic ammonoid faunas.__-----_-__----____-_--___-_-_-_-_-_-_---_-________ 15

Oloceras zone..--_----__--------------------_--^-__-_---___------_-----__--__---_-----_---_-____-_____ 15

Genodiscus zone.__--_-_------------------_-_---_-_-------------------------_-------_-------_---_-____ 15

Meekoceras zone..___-__--------------------_.---_-_-------------------_---___-_---___-----_-___-_-____ 15

Pseudosageceras imdtilobatum subzone-__-__-_---_-----------------------___-_---_---_-_-__-_________ 15

Owenites subzone._____-_-___-_-_-_-_-_-___-_-_-___-_____-_-_-____-______________________._..______ 16

Anasibirites subzone._-__-__--__-__--_-_________--__-----_-_-_-___-___________-__________________ 17

Tiroliles zone._________________________________________________________________________________________ 18

Columbites zone._______-_-_--_--!---_-_---_-_-___-----_---_-_---_-_-_-_-_____-___-_-_____-____________ 18

Outline of phylogeny of Triassic ammonites._______--____-_-_----___--_-_---_-___-______-_-______-______________ 20

Methods-.__.-.._._._._._---__-----_------_--.-._-__._-_----_-_-------_-_-_______________._______.______ 20

Pri nci pies-__-----_-__---_---------------------_-_---_-------_---------------_--_----------_----__-___-__ 21

Limitations of field considered.____----------_-_-_______-_---__-__--_---__----______-_-_._____.____________ 21

Recapitulation with examples.__-------__--_-----_______---_-_-_-___--__-_--_-J_____:.______________________ 22

Radicles. _..__-__________-----_-_-----------_-_______-------_---__--_-_---______-:_-_---------_____-____ 23

Phylogeny of Lower Triassic ammonites.______________---_-_°___________________________________________ 25

Synopsis of phylogeny of Lower Triassic ammonites._____________________________________________________ 26

Persistent goniatite stages in the Permian_______________________________________________________________ 26

Persistent gqniatite stages in the Lower Triassic_________________________________________________________ 26

Recapitulation of goniatite stages in the Permian.________________________________________________________ 27

Recapitulation of goniatite stages in the Triassic_________________________________________________________ 27

Geographic distribution of Lower Triassic genera.____--____-_--_-__--------_--______.____.__-.__-___________. 28

Phylogenetic classification__________________________________________________________________________________ 29

Gephyroceratea.__-_____-_-_--____-___----__-_____-____--___-_-_-_-__ _-_______-____________________._ 29

Superfamilj' Prolecanitoidea._______________________________________________________________________ 29

Family Xenodiscidae..________________________________________________________________________ 29

Family Meekoceratidae.___--_-___--_______-_-----__--_---_-----,______-___-_-___________.____ 31

Family Ceratitidae.___-_-_-___-_-__--_-_-_---_-'-_--_.--_-_-_-__--__.__________-___________.__ 31

Genus Frechites.-_---__-_-_--_-_-_-___--__-----_---__--_----__-___-_-___-_-______________ 32

Trachyceratea. __._____-_-__--_____-_---------_-----_---_---_______-______________._______ 33

Family Gymnitidae..-___---__-_--_____-___---_---_-_-_-------_--______-___-___-_-___________. 33

Lytoceras-Phylloceras stock___________________________________________________________________ 33

Fainily Pinacoceratidae.________________________________________________________________________ 33

Family Hungaritidae._____---_-_--________----_----_-___-_________.__________________,___.___ 34

Superfain ily 'Beloceratoidea.-_-------^--___----__--___-_-_-_____-_-_-___________________________--_ 34

Superfamily Dimorphoceratoidea.__________________________________________________________________ 35

Family Thalassoceratidae._____-_-_-__ .____-__-______-__ _____________________________________ 35

Family Haueritidae._-____---------___---------_-__--_____-_-----_____-___________________._. 35

Superfamily Pronoritoidea..._______________________________________________________________________ 35

Family Pronoritidae.____-_-_-_-_---_____-_--____---_----__-__-_-________-_______________.____ 35

Gastrioceratea.______________________________________________________________________________________ 3.6

Superfamily Tropitoidea._________________________________________________________________________ 36

Family Celtitidae...-_-_----------_________--.-_--------__----__-______________-_-____________ 36

Family Tropitidae.___________________________________________________________________________ 37

Family Haloritidae.___________________________________________________________________________ 38

Superfamily Arcestoidea.___._-_---_-__.__---_.------.--_-_----___-_.______-_.-_.__.__________.___ 38

Family Arcestidae.-----_------------_-__-_--__-_-----_----_-___-._________-_.________________ 38

Family Ptychitidae.--__------ --.__________--._-_--_--___-______.__._..__________________.____ 39

in
IV CONTENTS

	Page 

Systematic descriptions________-___-___________-_____-_____________-____'______________________________________ 39

Gephyroceratea_ ____-_---_-__--_-_---__-____________-__-__-___________._________-_____-_____-__-____-_.__ 39

Prolecanitoidea-___________-_-__-_______-__-____________-___-________ _____________-________._________ 39

Xenodiscidae.___________________________________________________________________________________ 39

Lecanites ____________________________________________________________________________________ 40

Paralecanites _____________________________________________________________________________ 40

Xenodiscus__ -___-_____-____-__^__________________________._________________________________ 42

Xenaspis- ___--_-_---_____________________---_-_______________-_-___-____-________.__...__ 46

Ophiceras-.___'__________-__-_____-_______________-___________________________-______________ 48

Flemingites__________________________________________________________________________________ 51

Meekoceratidae_ ___-__-_----____-______---___-___----_-_-_-______________________-_-________-_-__ 54

Meekoceras..________________________________________________________________________________ 54

Koninckites-_--____--___-___-____ _______________________________________________________ 60

Clypeoceras ___________ ___-___-__----_----__-----_-_^____-_-___-__--______________.-___..___ 62

Dagnoceras-_--------------_----------------_________________________________________________ 65

Kashmirites _________________________________________________________________________________ 66

Anasibirites _________---__-_-________-__--___--___-_-___-_______-_____-_____.____-______-_-__ 69

Goniodiscus._____________________________________________________________________________ 75

Hedenstroemia. ______________________________________________________________________________ 77

Clypites----.----.---..------------------.--------------.--.--._-_-----..----..-_--...... 79

Hungaritidae.___________----__-__-__-___-____---_-_-_-_-_____.__-__-___-_-_-__-__--.. ._.___.____ 79

Tnyoites.-------. _-_-_____.._-_____-___-___---_---_-_--____-__-.___--__- _______-___-.._.___.-_ 80

Dalmatites _________--__-___-_-_-__-.----.__-_-____-_--_.___________._.._-_._--_--._..___._._. 80

Pseudharpoceras. ___-_---_______________-___-_-_-____--___-__-__-__________________-____-_.__ 81

Ceratitidae.------------------------------------------------------------------------------------- 82

Tirolites..._______---_-----L-_-_-_--_---_--_--_-_-_-.-_.______._._____..__.__.._._...L....___ 83

Danubites--------------- --__-__-_-_-___-----_-_-_-_-_-_______.__ .-_.__________.._ ..___-__.___ 84

Beloceratoidea ____-_-__-_---------------------------_------------_--_----_-___---------_---___-___-_- 85

Sageceratidae.___________________________________________________________________________________ 85

Aspenites..__-_-____------__---_-----___-__-----__----___-_____ ________________ ______________ 85

Pseudosageceras------___-____-.__-________--._____-_______-_____-._________._____.-_____--.._ 87

Dimorphoceratoidea_ _____--___-_-_-_____-_-_________-_--__-_-_________-_____-___-_____-___-______--_. 89

Haueritidae. - ____________-----___------___-----_----------______-___-___-_---_-_---__---__-_---__ 89

Lanceolites ________-__---____-_--.-----_---____-____-_-____-_...._-___-___-______________.______- 89

Thalassoceratidae_ _._______-_______-__-_-_____-_-_-_-_-_--_..__-___.-__--____-_-__________________ 90

Ussuria._____-_-___-_--_-____------_------------_-----_-_---_-_-__-_-__-_-_-----_--__--.____ 91

Sturia...---__------------------------_-----------------------------_---------_-------_-_----- 93

Pronoritoidea._____._______-____----_-__-__---___-__-_--------_-____-_-_--__-_-_-__-_--_--____-_-___ 94

Pronoritidae_------------------------....-- ---.---------_-----_----------------_----------.._------- 94

Cordillerites ___.____-____.____________________-.-.----_.______.__.___.._.___._._._..._....... 95

Gastrioceratea L..---.------------------------.------------------------------------------------------------ 97

Arcestoidea.-- ._____-__.---_---- __-___---------------------_---_-___-_--.._-__----------------_------- 97

Cyclolobidae.-----------.------------------------------------------------------------------------ 97

Prosphingites _________________________________________________________________________________ 97

Ptychitidae.- .......^............................................................................. 98

Nannitinae. __-_-----------__----___-_-__-------------__-_-_---_-__-------..-------..-_---_-_- 98

Paranannites.---____-..__-___-_-_______-___-_-_________-_________--.-__.__--_-_-___-__.__- 98

Ptychitinae - .........................................................'-....... ...^... ........I.. 99

Owenites_ _ ____-_.-_._____-_____-_-_.---__-._-_-_-___-_..__-____-_.__--____--_-_-,_.-______ 99

Proptychites.____-__-_..__-__---_____-__--....._-__--________________________________---_.-- 101

Proteusites-____--_-_____._____________--__--__---_____.________-___.____________..___^__ 102

Tropitoidea- -.__-___--_-------__--..-_--_-_--_------------_-----_-----------------..---_-----....-.---- 103

Celtitidae.___---.___---------_--__-_--_---------_---------_-_---_-___---_-_------------__------- 103

Celtites.------------------------------------------------------------------------------------ 103

Columbites.__.____-._-______-_-___-_-_____.._..-_-__-..--____--_-_-_________-_-_----_-___--_--- 105

Haloritidae ____.-______---_---___-_-_---_-__-__---_----_-__-__-_----_--------------------_------- 108

Juvenites------- ....^............................................................^......-..-.- 108

Prenkites------------------------------------------------------------------ .___--_--_._------ 110

Thermalites..----------------------------- .___----__--___._-_________-_.--_-_---__---__--.--_-- Ill

Index.----...-.-. 1 --.------------------------------------.--------------------......------------------'.--------- 195
ILLUSTRATIONS

Page 

PLATES 1-81. Lower Triassic ammonoids________________________._____,_________________________________________ 113

FIGURE 1. Map showing geographic distribution of Lower Triassic faunas._-____.___________________ _________________ 14

INSERT

Correlation table of lower Triassic fauna?-.-,_-_-__--____-__----_____--___-_____-____-___--_-_-___________--.__ 14
LOWER TRIASSIC AMMONOIDS OF NORTH AMERICA

JAMES PERRIN SMITH

INTRODUCTION »

The writer has been engaged, under the auspices of 

the United States Geologic'al Survey, in the study of 

Lower Triassic faunas of North America since 1896, 

when the late Charles D. Walcott discovered the 

Mee/coceras-bearing beds in the Inyo Range of California and submitted the material collected for identification. This work has been followed up bjr frequent 

journeys in the field in California, Nevada, and Idaho 

and occasional studies in the United States National 

Museum.

The writer has visited all the principal localities for 

Lower Triassic ammonoids known in America and has 

had the assistance of numerous field parties of the 

United States Geological Survey, of Stanford University, and of the University of California and also of 

numerous friends outside these organizations.

Deep obligations are acknowledged to the late 

Charles D. Walcott and Alpheus Hyatt, for their 

generous interest and encouragement in the beginning 

of this work, and to George Otis Smith, director, and 

David White and T. W. Stanton, of the United States 

Geological Survey, for the opportunity of carrying on 

the work and publishing the results.

The writer also acknowledges his indebtedness to 

Dr. John C. Merriam, Mr. Henry W. Turner, Mr. 

A. M. Strong, and Mr. Oscar H. Hershey for assistance 

in the field and for the use of collections made by

i Prof. Jnuios Porrin Smith passed away January .1, 1931. It is greatly to be regretted that ho did not live to see this product of his labors in type. The manuscript had received its final revision at his hands, however, and was awaiting 

publication at the time of his death. The proofs have been read entirely by others, 

but no changes have been made aside from the correction of obvious errors. Editor.

them. Especial thanks are due to the late Robert S. 

Spence for his generous assistance in the field and for 

his skill, and enthusiasm in collecting the Lower 

Triassic faunas of the Wasatch Mountains.

The writer is also greatly indebted to Prof. Charles 

Schuchert, former curator of paleontology in the 

United States National Museum, for access to the 

types of the Hayden Survey collections and for the 

use of material for study; also to Prof. A. L. Mathews 

for the use of collections made by him in Utah.

Sincere gratitude is here expressed to the late Prof. 

Carl Diener, of Vienna and the Geological Survey of 

India, for the exchange of specimens and for constant 

aid and constructive criticism through a correspondence lasting for 30 years.

The writer also feels a deep sense of obligation to 

Prof.. G. von Arthaber, of Vienna, for his kindly 

interest and friendly suggestions that have been of 

great help in preparing the descriptions of this large 

and somewhat difficult fauna.

The writer desires to express his thanks to the people 

of those parts of California, Nevada, Idaho, and Utah 

where the collections were made, for their friendly 

helpfulness in the prosecution of the field work. He 

received everywhere the most sympathetic interest 

and cordial help.

The species of Lower Triassic ammonoids of North 

America described and illustrated in this paper are 

listed in the table below, which also shows their 

straligraphic position in North America and their 

occurrence in other parts of the world.

Lower Triassic ammonoids of North America

Mcckoccrns zone of Idaho

Name Illustrations Stratigraphic position Occurrence elsewhere

Locanitos arnoldi Hyatt and Smith....

Locunitos knechti Hyatt and Smith... 

Xonodjscus cordilloranus Smith.......

Xenodjscus gilbcrti Smith.............

Xonodiscus mtormontamis Smith.....

Xcnodisous tarpoyi Smith.............

Xonodiscus touhii Smith..............

Xonodiscus waagoni Hyatt and Smith. 

Xonodiscus whitcanus (Waagon) ...._. 

Ophicoras dicnori Hyatt and Smith_. 

Flomingitcs aplanatus (Whitu)........

Flomingitos asponensis Smith___....

Flomlugitos bannockonsis Smith.......

Flomingitos cirratus (White).---------

PI. 28, figs. S-10; pi. 39, figs. 9-12; pi. 64, figs. 1-16. ' 

PI. 9, figs. 11-16; pi. 28, figs. 1-7..............

PI. 24, figs. 21-29.

PI. 24, figs. 1-9.

PI. 24, figs. 10-20.................... .

PI. 25, figs. 4-6--...-........-.--..........

PI. 25, figs. 1-3; pi. 53, figs. 9-12..............

PI. 39, figs. 3-8..............................

PI. 25, fig. 17..............................

PI. 8, figs. 16-29.

Pseudosageceras multilobatum and Owenites 

subzoncs.

Pseudosageceras inultilobatum subzone.------

.do.

-do. 

.do.

Pseudosageceras multilobatum and: Owenites 

subzoncs. 

.do.

PI. 11, figs. 1-14; pi. 22, figs. 1-23; pi. 39, figs.

1, 2; pi. 04. figs. 17-22. 

PI. 23, figs. 6-11............................

PI. 23, figs. 18-26-..----.---------....- ..

PI. 20, fig. 1; pi. 26, figs. 1-13.....--.-..--

Pseudosageceras multilobatum subzone. .. 

. .do.-- ................

Pseudosageceras multilobatum and Owenites

subzone.

Pseudosageceras multilobalum subzone . 

.--.-do...-__- - ..... ....
LOWER TRIASSIC AMMONOIDS OF NORTH AMERICA

Lower Triassic ammonoids of North America Continued 

Meekoceras zone of Idaho Continued

Name Illustrations Stratigraphic position Occurrence elsewhere

Flemingites russelli Hyatt and Smith..

Flemingites russelli var. gracilis Smith. 

Meekoceras arthabcri Smith... __

PI. 1, figs. 1-3; pi. 26, figs. 14-23; pi. 70, figs.

1-3. 

PI. 23, figs. 1-3-----------.-.-,-------------

PI. 32, figs. 26-33----------..-------------

.do. 

_do.

Meekoceras cristatum Smith.._ .. .. 

Meekoceras evansi Smith.--.---------------.

Meekoceras gracilitatis White-- --------

Meekoceras mushbachanum White.... 

Meekoceras mushbachanum var. corrugatum Smith. 

Meekoceras patelliforme Smith.............

Meekoceras sylvanum Smith. ............

Clypeoceras muthianum (Krafft) _......

Dagnoceras bonnevillense Smith............

Dagnoceras bridges! Smith.......-..---....

Dagnoceras haydoni Smith. - - 

Dagnoceras pealei Smith_................

Hedenstroemia hyatti Smith.. ----------

Hedenstroemia kossmati Hyatt and Smith_

Hedenstroemia tenuis Hyatt and Smith.... 

Dalmatites richardsi Smith.-- -- - -. . 

Juvenites dieneri Hyatt and Smith.........

Juveniles kraffti Smith.-......-..-....-_..

Juvenites sanctorum Smith__------------

Juvenites scptentrionalis Smith............

Paranannites aspenensis Hyatt and Smith.

Paranannites columbianus Smith....._.....

Paranannites eompressus Smith............

Paranannites pertenuis Smith..............

Prenkites dopressus Smith...--- --. --. 

Thermalites thermarum Smith._.........

Ussuria occidentalis Smith._..............

Ussuria waageni Hyatt and Smith......_...

Lanceolitcs compactus Hyatt and Smith... 

Cordillerites angulatus Hyatt and Smith... 

Aspenites acutus Hyatt and Smith.........

PI. 33, figs. 14-19; pi. 34, figs. 1-6............

PI. 35, figs. 1-3; pi. 36, figs. l-\»'.............

PI. 12, figs. 1-13; pi. 13, figs. 1-1.8; pi. 14, figs.

1-8; pi. 36, figs. 19-28; pi. 37, figs. 1-7; pi. 38,

figs. 2-6; pi. 70, figs. 4-7. 

PI. 15, figs. 1-9; pi. 16, figs. 1-3; pi. 18, figs.

1-7; pi. 38, fig. 1; pi. 70, figs. 8-10; pi. 74, figs.

1-25; pi. 75, figs. 1-6; pi. 76, figs. 1, 2. 

PI. 38, fig. 1........--.-.-. ..-.---...--..

Pseudosageceras multilobatum and Owenites

subzones.

Pseudosageceras multilobatum subzone..--.-. 

.....do - --

Pseudosageceras multilobatum and Owenites 

subzones.

PI. 28, figs. 21-27; pi. 52, figs. 9-11...-------

PL 33, figs. 1-14. 

PL 27, figs. 1-7- 

Pl. 29, figs. 9-23. 

PL 31, figs. 1-7-

Pseudosageceras multitobatum subzone.

Pseudosageceras multilobatum and Owenites

subzones. 

Pseudosageceras multilobatum subzone-......

.----do....-----..---------------.-----------.

Pl. 29, figs. 1-8... 

PL 29, figs. 24-37. 

PL 27, figs. 13-18.

_do_ 

.do. 

.do.

Lower Triassic of Timor?

Flemingites beds of India.

Pl. 28, figs. 11-16; pi. 41, figs. 1-10; pi. 67, figs.

3-7. 

PL 1, figs. 4-8-- 

.do. 

.do.

.do.

.do.

PL 7, figs. 5-25; pi. 32, figs. 1-10....-------

PL 21, figs. 1-10---.---..---------..--...

PL 31, figs. 22-30--. --.-------------.

PL 31, figs. 31-40------..---.-.-------------

PL 8, figs. 1-15; pi. 73, figs. 1-30...---------

PL 32, figs. 11-25. 

Pl. 31, figs. 19-21. 

PL 31, figs. 13-15-

Pseudosageceras mullilobatum and Owenites

subzones.

Pseudosageceras multilobatum subzone. . . 

 do......................................

.do.

Pseudosageceras multilobatum and Owenites

subzones.

Pseudosageceras multilobatum subzone---.... 

.....do... ..... .............. ......

PL 31, figs. 16-18. 

PL 21, figs. 11-20. 

PL 27, figs. 8-12.

.do. 

.do. 

.do.

Aspenites laevis Welter_ ....

Aspenites obtusus Smith.... 

Pseudosageceras multilobatum N celling.._

PL 21, figs. 24-40; pi. 42, figs. 1-8; pi. 65, figs.

1-5; pi. 66, figs. 1-12; pi. 67, figs. 1, 2. 

PL 4, figs. 4-10; pi. 5, figs. 7-9; pi. 21, figs. 21-

23; pi. 28, figs. 17-20; pi. 40, figs. 9-11. 

PL 2, figs. 1-8; pi. 42, figs. 14-20; pi. 68, figs.

1-10; pi. 71, figs. 1-6. 

PL 2, figs. 9-13; pi. 3, figs. 1-5; pi. 30, figs. 1-26.

PL 28, figs. 28-33...

PL 31, figs. 8-lO_...

PL 4, figs. 1-3; pi. 5,1

pi. 63, figs. 1-6.

.do.

Pseudosageceras multilobatum and Owenites

subzones. 

Pseudosageceras multilobatum subzone---.-..

s. 1-6; pi. 25, figs. 7-16;

Pseudosageceras multilobatum and Oioenites

subzones.

Pseudosageceras multilobatum subzone -.-.. 

_-do....._.__.. __._...._-..--. 

Pseudosageceras multilobatum and Owenites

subzones and Columbites zone.

Owenites beds of Timor. 

Do.

Flemingites beds of India and 

Timor.

Owenites fauna of California and Nevada

Lecanites arnoldi Hyatt and Smith.

Lecanites knechti Hyatt and Smith.... ...

Xenodiscus cordilleranus Smith_..........

Xenodiscus marcoui Hyatt and Smith.......

Xenodiscus nevadanus Smith_------------

Xenodiscus nivalis Diener...................

Xenodiscus toulai Smith.

Xenodiscus waageni Hyatt and Smith. 

Ophiceras parvum Smith... _ 

Ophiceras sakuntala Diener_.......

Ophiceras subquadratum Smith. 

Flemingites aplanatus (White)..

Meekoceras arthaberi Smith.. 

Meekoceras elkoense Smith... 

Meekoceras gracilitatis White.

Meekoceras mushbachanum White... ... 

Meekoceras newberryi Smith......

Meekoceras patelliforme Smith.....

Meekoceras radiosum Waagen......

Meekoceras sanctorum Smith_-.-.-......

M eekoceras strong! Smith.................

Meekoceras tuberculatum Smith..........

Clypeoceras hooveri Hyatt and Smith,....

Clypeoceras pusillum Smith...............

Hedenstroemia kossmati Hyatt and Smith.

Anasibirites desertorum Smith.........

Anasibirites lindgreni Smith. . 

Anasibirites noetlingi Hyatt and Smith. 

Qoniodiscus typus Waagen.............

PL 28, figs. 8-10; pi. 39, figs. 9-12; pi.

figs. 1-16. 

PL 9, figs. 11-16; pi. 28, figs. 1-7.

PL 24, figs. 21-29.

PL 7, figs. 26-33. -----------

PL 56, figs. 1-5.-. .-----------------

PL 56, figs. 6-12 

PL 25, figs. 1-3; pi. 53, figs. 9-12. 

PL 39, figs. 3-8-

Pl. 54, figs 25-30 

PL 54, figs. 1-17; pi. 56, figs. 13-18.

PL 54, figs. 18-24.......................

PL 11, figs. 1-14; pi. 22, figs. 1-23; pi. 39,

1, 2; pi. 64, figs. 17-22. 

PL 32, figs. 26-33.......................

PL 55, figs. 14-16.

PL 12, figs. 1-3; pi. 13, figs. 1-18; pi. 14, figs.

1-8; pi. 36, figs. 19-28; pi. 37, figs. 1-7; pi. 38,

figs. 2-6; pi. 70, figs. 4-7. 

PL 15, fifes. 1-9; pi. 16, figs. 1-3; pi. 18, figs.

1-7; pi. 38, fig. 1; pi. 70, figs. 8-10: pi. 75, figs.

1-6; pi. 76, figs. 1-3: pi. 79, figs. 1-23. 

PL 53, figs. 1-4 - .. - ._ 

PL 28, figs. 21-27; pi. 52, figs. 9-11-.... ...

PI. 51, figS. iHl . .

PL 49, figs. 

PL 52, figs. 

PL 50, figs.

12-17. 

1-4.._ 

Pl. 17, 1-12..

PL 51, figs. 11-13...

PL 28, figs. 11-16; pi. 3-7.

PL 51, figs. 

PL 53, figs. 

PL 9, figs.

, 7-10; pi.

13-17...

1-3......

41, figs. 1-10; pi. 67, figs. 

56, figs. 19,20 --.-.

Pseudosageceras multilobatum and Owenites

subzones. 

. do. 

Owenites subzone. 

....do ......

. do.............

Pseudosageceras multilobatum and Owenites 

subzones.

 do............. ...... _ _ -_-

Owenites subzone__.......................

 do. ..---.- - .............

.do.

Pseudosageceras multilobatum and Owenites 

subzones. 

do.

Owenites subzone_ 

Pseudosageceras mullilobatum and Owenites 

subzones.

Owenites subzone - - 

Pseudosageceras multilobatum and Oioenites

subzones. 

Owenites subzone__.......................

Columbites zone. 

Owenites subzones.

-do. 

.do.

-do.

Pseudosageceras multilobatum and Owenites

subzones. 

Owenites subzone ..................

.....do__ .

-..do.. . . .......

.. do........ . ..

Flemingites beds of India and 

Timor.

Lower Triassic of India and 

Albania.

Flemingites beds of Timor?

Lower Triassic of India and 

Albania.

Anasibirites beds of Timor?

Anasibiriles beds of India and 

Timor.
INTRODUCTION

Lower Triassic ammonoids of North America Continued

Owenttes fauna of California and Nevada Continued

Name

Juveniles (lieneri Hyatt and Smith.......... 

Pnranannitos asponensis Hyatt and Smith....

Proteusites rotundus Smith _ ..............

Ovvonitos kooneni Hyatt and Smith _ ......

Owonitos zittoli Smith.... ...................

Sturia woodini Smith __ . __ ..............

Lanccolitos coinpaetus Hyatt and Smith _ .

Psoudosagocoras multilobatum Noetling _ ..

Illustrations

PI. 0, figs. 1-16; pi. 40, Hgs. 1-8; pi. 69, figs. 1-9.

Pl. 7, figs. 5-25; pi. 32, flgs. 1-10.............. 

PI. 8, flgs. 1-15; pi. 73, flgs. 1-30... ...........

PI. 9, flgs. 4-10. ........... __ ... ____ ...

PI. 19, flgs. 1-7; pi. 52, flgs. 18-20.............

PI. 53, flgs. 5-8...... ......... ......

PI. 54, flgs. 31-34........ ......... ........

PI. 52, flgs. fi-8.. . 

PI. 10, flgs. 1-23....-..--.--.......--........

PI. 52, flgs. 1-15. : 

PI. 7, flgs. 1-4...............................

PI. 3, flgs. 0-11__ __...._ 

PI. 51, figs. 5, 6--.--..---------...-.----.-...

PI. 4, flgs. 4-10; pi. 5, figs. 7-9; pi. 21, flgs. 21- 

23; pi. 28, figs. 17-20; pi. 40, figs. 9-11.

PI. 2, flgs. 9-13; pi. 3, flgs. 1-5; pi. 30, flgs. 1-26.

PI. 4, figs. 1-3; pi. 5, figs. 1-6; pi. 25, figs. 7-16; 

pi. 63, figs. 1-6.

Stratigraphic position

Pseudosageceras multilobatum and Owenites 

subzones. 

.. do. 

.....do.............................

 do........... .........................

.....do.......................................

.....do............................. ........

.-.-.do....... ................................

...-do.......................................

. do............. .......................

. do........... ............................

.....do... ............ ......

Pseiidosageceras multilobatum and Owenites 

subzones.

subzones. 

Pseudosageceras multilobatum and Owenites 

subzones and Columbites zone.

Occurrence elsewhere

Flemingites beds of Timor and 

India.

Anasibirites fauna of Utah

quicostatus Waagon.

Mathows.

PI. 79, flgs. 3, 4..............................

PI. 79, flgs. 5, 6.............................

PI. 79, flgs. I, 2..............................

PI. 79, flgs. 7, 8..............................

PI. 79, flgs. 13-15 

PI. 80, flgs. 3-5. .............................

PI. 79, figs. 11, 12............................

PI. 79, figs. 19-21................. __ .......

PI. 79, figs. 16, 17...-..-....--.........---...

PI. 80, figs. 1, 2.....- ...... - . _-

PI. 79, figs. 9, 10 . . -.

PI. 80, figs. 11, 12... ._- _ . 

PI. 80, flgs. 13-15----- -------------

PI. 80, figs. 9, 10 . 

PI. 81, flgs. 1, 2..............................

PI. 81, flgs. 9, 10.............................

PI. 81, flgs. 11, 12 . 

PI. 81, flgs. 3-5. 

.....do....... ................... .............

... ..do... . ..

 do 

.....do.......................................

..... do.. ........... .....................

.....do...... .................................

..... do . .. ...... ..... ......

.....do. ............... ........... ...

.. ...do....... ............... ............... ..

... ..do... ... 

....-do.......... ... ..........

_ do .... ... 

 do _ 

 do.. . ......

 do ............ ...

..... do.. ........ ....................... ......

.....do ........ .......................... -.

 ..do... 

.....do......... ........... ............ ......

.... .do....... _..-. .-.-_.. .. -_. 

 do .. .

..... do........... .........................

...-do.... ....-...-........-..-....... .

 do... 

and Timor.

Timor. 

Do.

Timor.

Do.

Do.

Do.

Timor.

Do.

Do.

Tirolites fauna of Idaho

PI. 57, figs. 9, 10 

PI. 57, figs. 1-4.. - .... .do... ... 

 do 

Columbites fauna of Idaho

Ophicorns jacksoni Hyatt and Smith_.. 

Ophicoras sponcoi Hyatt and Smith.....

Mookoconis curticostatum Smith........

Mookocoras inicroinphalus Smith__....

Mookocorns pilatum Hyatt and Smith... 

Mookoccras sanctorum Smith ......

Pseudharpocorns iclahopnso Smith.......

Tirolitos illyricus Mojsisovics_.........

Psoudosagecoras multilobatum Noetling.

Coltites apostolicus Smith...... .........

Coltitos planovplvis Smith...............

Coltites ursonsis Smith..................

Columbites consnngtiineus Smith._....

Columbitos ligatns Smith_ ........

Columbitos minimus Smith.............

Columbites ornatus Smith... 

Columbitos parisianus Hyatt and Smith.

Columbitos spencoi Smith...................

PI. 62, figs. 11-21. 

PI. 62, figs. 1-10.. 

Pl. 48, figs. 21-30.

Pl. 49, flgs. 5-11. 

PI. 63, figs. 7-13.. 

PI. 49, figs. 1-4... 

Pl. 49, figs. 17-19.

PI. 4, flgs. 1-3; pi. 5, flgs. 1-6; pi. 25, flgs. 7-16;

pi. 63, flgs. 1-6. 

PI. 48, flgs. 1-10.

PI. 48, flgs. 11-20 .--- -----

PI. 47, figs. 11-23---.---... ._..... 

PI. 46, flgs. 1-13. . . -

PI. 47, flgs. 1-8.

PI. 47, flgs. 9, 10... 

PI. 46, figs. 14-21... .. 

PI. 1, figs. 9-14; pi. 61, figs. 1-21; pi. 72,

1-24. 

PI. 77, figs. 1-21; pi. 78, flgs. 1-16 

Columbites zone.

..... do ......

.. do ......

.do. 

.do. 

.do.

.do. 

.do.

Pseudosageceras multitobatum and Oioenites

subzones and Columbites zone. 

Columbites zone..--. .... . ....-... .

.....do.- ...------ ............

.....do... 

.do. 

.do. 

.do. 

-do. 

.do.

Werfeu beds of Tyrol. 

Flemingites beds of India and 

Timor.
LOWER TRIASSIC AMMONOIDS OP NORTH AMERICA

The present work is the fifth in a series planned 

many years ago, to cover the stratigraphy and geologic 

history of the Cephalopoda through the late Paleozoic 

and early Mesozoic eras. The other works of the 

series, in order of publication, are the following:

The Carboniferous ammonoids of America: U. S. Geol. 

Survey Mon. 42, 1903. The purpose of this monograph was 

to lay the foundation for the study of the ancestors of the 

Mesozoic faunas.

The Triassic cephalopod genera of America: U. S. Geol. 

Survey Prof. Paper 40, 1905. This paper was written in conjunction with Alpheus Hyatt and described a typical species 

under each cephalopod genus known in the Triassic of North 

America at that time.

The Middle Triassic marine invertebrate faunas of North 

America: U. S. Geol. Survey Prof. Paper 83, 1914.

Upper Triassic marine invertebrate faunas of North America: 

U. S. Geol. Survey Prof. Paper 141, 1927.

The writer has also completed two other monographs in the same series and on kindred subjects, 

as follows:

Permian ammonoids of Timor: 2e Nederlandsche TimorExpeditie onder Leiding van Dr. H. G. Jonkert, uitgegeven 

door Dr. H. A. Brouwer: Jaarboek van het Mijnwezen in Ned. 

Indie, 1926, Verh. 1, 1927.

Lower Triassic ammonoids of Timor (MS.).

These papers have been of great value in the study 

of the genealogy and relationships of the early Mesozoic faunas of North America. Acknowledgment is 

hereby made to Dr. H. A. Brouwer, of Delft, Holland, 

for the opportunity of studying the collections made 

by him and his field parties in Timor.

BIBLIOGRAPHY

The principal papers that describe the Lower Triassic ammonoids are listed in the following bibliography.

ARTHABER, G. VON, Die Cephalopodenfauna der Reiflinger 

Kalke: Beitr. Palaontologie Oesterr.-Ungarns u. des 

Orients, Band 10, 1896.

 Das jiingere Palaozoicum aus der Araxes-Enge bei 

Djulfa (in Frech, F., and Arthaber, G. von, Ueber das 

Palaozoicum in Hocharmenien und Persien, etc.): Beitr. 

Paliiontologie Oesterr.-Ungarns u. des Orients, Band 12, 

1900.

 - Neue Funde in den Werfener Schichten und im Muschelkalke des siidlichen Bakony, und Revision der Cephalopodenfauna des Muschelkalkes: Resultate der wissenschaftlichen Erforschung des Balatonsees, Band 1, Teil 1, 

1903.

 Die Alpine Trias des Mediterran-Gebietes: Lethaea 

geognostica, Teil 2, Das Mesozoicum, Band 1, Lief. 3, 1906.

 Ueber die Entdeckung von Untertrias in Albanien und 

ihre faunistische Bewertung: Geol. Gesell. Wieri Mitt., 

Band 1, 1908.

Die Trias von Albanien: Beitr. Palaontologie Oesterr.-

Ungarns u. des Orients, Band 24, 1911. 

 Die Trias von Bithynien (Anatolien): Beitr. Palaontologie Oesterr.-Ungarns u. des Orients, Band 27, 1914.

BRANCO, W., Beitrage zur Entwickelungsgeschichte der fossilen

Cephalopoden: Palaeontographica, Band 26, 1879 (Teil 1);

Band 27, 1880 (Teil 2). 

DIENER, CARL, Cephalopoda of the Muschelkalk: India Geol.

Survey Mem., Palaeontologia Indica, 15th ser., Himalayan

fossils, vol. 2, pt. 2, 1895. 

 Triadische Cephalopodenfaunen der ostsibirischen Kiistenprovinz: Com. g<§ol. [St.-Pe"tersbourg] M6m., vol. 14,

No. 3, 1895.

Cephalopoda of the Lower Trias: India Geol. Survey

Mem., Palaeontologia Indica, 15th ser., Himalayan fossils, 

vol. 2, pt. 1, 1897.

 - Mittheilung iiber Cephalopoden-Arten aus der Trias 

des siidlichen Bakony: Resultate der wissenschaftlichen 

Erforschung des Balatonsees, Band 1, Teil 1, Pal. Anhang, 

1899.

 Entwurf einer Systematik der Ceratitiden des Muschetkalkes: K. Akad. Wiss. Wieri Sitzungsber., Band 114, 1905.

 Ueber einige Konvergenzerscheinungen bei triadischen 

Ammoneen: K. Akad. Wiss. Wien Sitzungsber., Band 114, 

1905.

 The fauna of the Himalayan Muschelkalk: India Geol. 

Survey Mem., Palaeontologia Indica, 15th ser., Himalayan 

fossils, vol. 5, Mem. 2, 1907.

 The Trias of the Himalayas: India Geol. Survey Mem., 

vol. 36, pt. 3, 1912.

 Triassic faunae of Kashmir: India Geol. Survey Mem., 

Palaeontologia Indica, new ser., vol. 5, Mem. 1, 1913.

 Ammoniten aus der Untertrias von Madagascar: K. 

Akad. Wiss. Wien Sitzungsber., Band 133, 1914.

 Die marinen Reiche der Triasperiode: K. Akad. Wiss. 

Wien Denkschr., Band 92, 1916.

 Ueber Ammoniten mit Advent!vloben: K. Akad. Wiss. 

Wien Denkschr., Band 93, 1917.

 and KRAFFT, A. VON. See Krafft, A. von, and Diener,

Carl. 

DOTJVILLE, H., Sur la d^couverte du Trias marin a Madagascar:

Soc. geol. France Bull., 4th ser., vol. 10, 1910. 

FBECH, FRITZ, Die Dyas: Lethaea geognostica, Teil 1, Das

Palaeozoicum, Band 2, Lief. 3, 1901; Lief. 4, 1902.

 - Einleitung des Mesozoicum und der Trias, und 

Continentale Trias: Lethaea geognostica, Teil 2, Das 

Mesozoicum, Band 1, Trias, Lief. 1, 1903.

 Ueber Devonische Ammoneen: Beitr. Palaontologie 

Oesterr.-Ungarns u. des Orients, Band 24, pp. 27-111, 1901. 

Die Zirkumpacifische Trias: Lethaea geognostica, Teil

2, Das Mesozoicum, Band 1, Lief. 4, Trias, pp. 488-509,1908. 

GEMMELLARO, G. G., La fauna dei calcari con Fusulina della

valle del Fiume Sosio nella provincia di Palermo, 1887. 

GIRTY, G. H. Descriptions of new species of Carboniferous and

Triassic fossils: U. S. Geol. Survey Prof. Paper 152, Appendix, 1927. 

GRIESBACH, C. L., Paleontological notes on the Lower Trias

of the Himalayas: India Geol. Survey Rec., vol. 13, 1880. 

HAAN, G. DE, Monographiae ammoniteorum et goniatiteorum

specimen, 1825. 

HANIEL, C. A., Die Cephalopoden der Dyas 'von Timor:

Palaeontologie von Timor, Lief. 3, 1915. 

HAUER, F. VON, Die Cephalopoden des Salzkammergutes aus

der Sammlung des Fiirsten Metternich, Wien, 1846.

 Cephalopoden aus der Unteren Trias der Alpen: K. 

Akad. Wiss. Wien Sitzungsber., Band 52, 1865.

 Cephalopoden des bosnischen Muschelkalkes von Han 

Bulog bei Sarajevo: K. Akad. Wiss. Wien Denkschr., 

Band 54,1887.
BIBLIOGRAPHY

HAUER, F. VON, Beitrage /Air Kenntniss der Cephalopoden aus 

der Trias von Bosnien, I: K. Akad. Wiss. Wien Denkschr., 

Band 59, 1892.

 Beitriige zur Kenntniss der Cephalopoden aus der Trias 

von Bosnien, II: K. Akad. Wiss. Wien Denkschr., Band 63, 

1896.

HAUO, E., Lcs ammonites du Permien et du Trias: Soc. g6ol. 

France Bull., 3d ser., vol. 22, 1.894.

 Etudes sur les Goniatitcs: Soc. gdol. France Mdm.,

Paldontologie, Mdm. 1.8, 1898. 

Hoi'jEArFEL, E., Die Cephalopoden des Domanik im sikllichen

Timan: Com. gdol. [St.-Pdtersbourg] M6m., vol. 12, No. 3,

1899. 

EYATT, ALIM-IEUS, Genera of fossil cephalopoda: Boston Soc.

Nat. Hist. Proc., vol. 22, 1883.

 Cephalopoda: In Zittel, K. A. von, Textbook of palaeontology (translated by C. E. Eastman), 1900. 

HYATT, ALPHEUS, and SMITH, J. P., The Triassic cephalopod

genera of America: U. S. Geol. Survey Prof. Paper 40, 1905. 

KAIUMNSICY, A., Ueber die Amrnoneen der Artinsk-Stufe und

einige rnit denselben verwandten carbonischen Formen:

Acad. imp. sci. St.-P6tersbourg Mdm., 7th ser., vol. 37,

No. 2, 1.889. 

KITTL, EitNST, Die Cephalopoden der oberen Werfener Schichten

von Mud in Dalmatien, sowie von andcren dalmatinischen,

bosnisch-herzegowinischen und alpinen Lokalitiiten: K.-k.

geol. Eeichsanstalt Wien Abh., Band 20, Heft 1, 1903. 

KONINCK, L. G. DE, Descriptions of some fossils from India,

discovered by Dr. A. Fleming, of Edinburgh: Geol. Soc.

London Quart. Jour., vol. 19, 1863. 

KitAFi'T, A. VON, and DIENEH, CARL, Lower Triassic

Cephalopoda from Spiti, Malta Johar, and Byans: India

Geol. Survey Mem., Palaeontologia Indica, 15th ser.,

vol. 6, Mem. 1, 1909. 

MANSFIELD, G. .R., Geography, geology, and mineral resources

of part of southeastern Idaho: U. S. Geol. Survey Prof.

Paper 152, 1927. 

M ATI-IE ws, A. A. L., The Lower Triassic cephalopod fauna of the

Fort Douglas area, Utah: Walker Mus. Mem., vol. 1,

No. 1, 1929. 

MO.ISISOVICS, E. VON, Ueber die Entwicklung von Ammoniten

in der carbonischen Formation Indiens: K.-k. geol.

Eeiclisansta.lt Wien Verb., 1872.

 Das Gebirge urn Hallstatt; Die Mollusken-Faunen der 

Zlambach und Hallstatter Schichten: K.-k. geol. 

Eeichsanstalt Wien Abh., Band 6, Teil 1, 1873.

 Vorlaufige kurze Uebcrsicht der Ammoniten-Gattungen 

der mediterranen und juvavischen Trias: K.-k. geol. 

Eeichsanstalt Wien Verb., 1879.

 Die Cephalopoden der mediterranen Triasprovinz: 

K.-k. geol. Eeichsanstalt Wien Abb., Band 10, 1882.

 Arktische Triasfaunen; Beitrage zur paliiontologischen 

Charakteristik der arktisch-pacifischen Triasprovinz: Acad. 

imp. sci. St.-Pdtersbourg Mdm., 7th ser., vol. 33, No. 6, 

1886.

 Das Gebirge um Hallstatt; Die Cephalopoden der 

Hallstatter Kalke: K.-k. geol. Eeichsanstalt Wien Abh., 

Band 6, Halfte2, 1.893.

 Beitriige zur Kenntniss der obertriadischen Cephalopoden Faunen des Himalaya: K. Akad. Wiss. Wien Denkschr., 

Math.-nat. Klasse, Band 63, 1896.

 Das Gebirge urn Hallstatt; Die Cephalopoden der 

Hallstatter Kalke: K.-k. geol. Eeichsanstalt Wien Abb., 

Band 6, Supplement-Heft, 1902.

MUENSTER, G. GRAF zu, Ueber das Kalkmergel-Lager von St. 

Cassian in Tyrol, und die darin vorkommenden Ceratiten: 

Neues Jahrb., 1834.

 Beitrage zur Geognosie und Petrifactenkunde des

Siidostlichen Tiro Is, vol. 4, 1841. 

MURCHISON,' E. I., VERNETJIL, EDOUARD DE, and KEYSERLING,

ALEXANDER VON, The geology of Eussia in Europe and

the Ural Mountains, Palaeontology, vol. 2, pt. 3, 184.5. 

NATIIORST, A. G., Beitrage zur Geologic der Baren-Insel,

Spitsbergens und des Konig-Karl-Landes: Geol. Inst.

Upsala Bull., vol. 11, 1910. 

NEUMAYR, M., Die Ammoniten der Kreide und die Systematik

der Ammoniten: Deutsche geol. Gesell. Zeitschr., Band 27,

1875. 

NOETLING, F., Untersucbungen ueber den Bau der Lobenlinie

von Pseudosageceras multilobalum Noetling: Palaeontograpbica, Band 51, 1905.

 Die asiatische Trias: Letbaea geognostica, Teil 2, Das

Mesozoicum, Band 1, Trias, Lief. 2, 1905. 

PHILIPPI, E., Die Ceratiten des oberen deutschen Muscbelkalkes: Paleont. Abh. (Dames & Koken), n. F., Band 4,

1901. 

SCHELLWIEN, E., Trias, Perm und Carbon in China: Phys.-

okon. Gesell. Konigsberg Scbrift., Band 43, pp. 59-78,

pi. 3, 1902. 

SCHMIDT, H., Die carboniscben' Goniatiten Deutscblands:

Preuss. geol. Landesanstalt Jabrb., Band 45, 1925. 

SMITH, J. P., Classification of marine Trias: Jour. Geology, vol.

4, No. 4, 1896.

 Geographic relations of the Trias of California: Jour. 

Geology, vol. 6, No. 8, 1898.

 The border line between Paleozoic and Mesozoic in

western America: Jour. Geology, vol. 9, No. 6, 1901.

 The Carboniferous ammonoids of America: U. S. Geol. 

Survey Mon. 42, 1903.

 The comparative stratigraphy of the marine Trias of 

western America: California Acad. Sci. Proc., 3d ser., 

Geology, vol. 1, No. 10, 1904.

 The Middle Triassic marine invertebrate faunas of 

North America: U. S. Geol. Survey Prof. Paper 83, 1904.

 The stratigraphy of the western American Trias: 

Festschrift, Adolf von Koenen, Gewidmet von seinen 

Schulern, 1907.

 Upper Triassic marine invertebrate faunas of North 

America: U. S. Geol. Survey Prof. Paper 141, 1927.

 Permian ammonoids of Timor; > 2C Nederlandsche 

Timor-Expeditie onder Leiding van Dr. H. G. Jonkert, 

uitgegeven door Dr. H. A. Brouwer: Jaarboek van het 

Mijnwezen in Ned. Indie, 1926, Verb. 1, 1927.

 The transitional Permian ammonoid fauna of Texas: 

Am. Jour. Sci., 5th ser., vol. 17, January, 1929.

 and HYATT, ALPHEUS. See Hyatt, Alpheus, and Smith,

J: P.

SPATH, L. F., On ammonites from Spitsbergen: Geol. Mag., 

vol. 58, Nos. 685, 686, 1921.

 Eotriassic ammonites from East Greenland: Geol. 

Mag., vol. 64, 1927.

STOLLEY, E., Zur Kenntniss der arktischen Trias: Ncues Jahrb., 

1911, Band 1, pp. 114-126.

SXJESS, E., Ueber Ammoniten: K. Akad. Wiss. Wien Sitzungsber., Band 30, 1869.

WAAGEN, W., Producius limestone fossils: India Geol. Survey 

Mem., Palaeontologia Tndica, 13th ser., Salt Eange fossils, vol. 1, 1897.
6 LOWER TRIASSIC AMMONOIDS OF NORTH AMERICA

WAAGEN, W., Preliminary notice on the Triassic deposits of the 

Salt Range: India Geol. Survey Rec., vol. 25, 1892.

 Vorlaufige Mittheilung iiber die Ablagerungen der 

Trias in der Salt Range: K.-k. geol. Reichsanstalt Wien 

Jahrb., Band 42, 1892.

 Fossils from the Ceratite formation: India Geol. Survey Mem., Palaeontologia Indica, 13th ser., Salt Range 

fossils, vol. 2, 1895.

WANNER, J., Triaspetrifakten der Molukken und des Timorarchipels: Neues Jahrb., Beilage-Band 24, 1907.

 Triascephalopoden von Timor und Rotti: Neues Jahrb.,

Beilage-Band 32, 1911. 

WEUEKIND, R., Die Genera der Palaeoammonoidea (Gonfatiten):

Palaeontographica, Band 62, 1917. 

WELTER, 0. A., Die Ammoniten der Unteren Trias von Timor:

Talaeontologie von Timor, Lief. 11, Abh. 19, 1922. 

WHITE, C. A., Fossils of the Jura-Trias of southeastern Idaho:

U. S. Geol. and Geog. Survey Terr. Bull., Vol. 5, 1879.

 Contributions to invertebrate palaeontology, No. 5, 

Triassic fossils of southeastern Idaho: U. S. Geol. and 

Geog. Survey Terr. Twelfth Ann. Kept., pt. 1, 1880.

The Texan Permian and its Mesozoic types of fossils:

U. S. Geol. Survey Bull. 77, 1891. 

YEHAHA, S., The lower .Triassic cephalopod and bivalve fauna

of Shikoku: Japanese Jour. Geology and Geography,

vol. 5, No. 4, pp. 135-172, March, 1928. 

ZITTEL, K. A. VON, Grundziige der Palaontologie, 6th ed.

(edited by Ferdinand Broili), 1924.

GENERAL FEATURES OF THE LOWER TRIASSIC 

AMMONOID FAUNA

The Lower Triassic ammonoid fauna of North 

America now amounts to 32 genera and 117 species, 

distributed among the following families: Xenodiscidae 

25 species, Meekoceratidae 38, Hungaritidae 4, Ceratitidae 6, Thalassoceratidae 4, Pronoritidae 2, Haueritidae2,Sageceratidae4, Ptychitidae 16, Haloritidae 6, 

Arcestidae 1, and Celtitidae 9.

Only three genera are peculiar to America Lanceolites, Cordillerites, and Thermalites and even these will 

probably be discovered in other regions, just as has 

happened with other so-called American genera. 

Meekoceras, Columbites, Paranannites, Juvenites, Owenites, and Inyoites were first described from America, this 

being merely an accident of discovery, as they all occur 

in other regions.

The Xenodiscidae, Meekoceratidae, and Hungaritidae are almost certainly immigrants from the Indian 

region. The Pronoritidae and Thalassoceratidae are 

probably native Americans, as may be also the Arcestidae, if the early development of these stocks in the 

American "Upper Coal Measure" is an indication.

Tirolites, the most common representative of the 

Ceratitidae, is plainly an immigrant from the European 

Mediterranean.

The Celtitidae appear in America, on one side, and 

in Albania, on the other, but are wholly lacking in the 

Indian region, which lies between the two. It would 

seem that they can hardly be indigenous in either region 

where they are known but that they must be immigrants from some outside source connected with both

regions but not with the Indian region. Such a source 

may be found in the Arctic province, for the Columbites 

fauna of Idaho shows strong affinities with that of the 

Olenek horizon in northern Siberia, and even one doubtful Columbites occurs there. 1 The migration from the 

Arctic region to Albania must have followed the ancient 

depression parallel with the Urals, along which, in 

Upper Triassic time, Pseudomonotis ochotica came to 

the eastern Mediterranean. The approach to the 

western American region must have been made 

through the Bering portal and along the ancient shoreline highway. Migrations along this line took place 

before and long after the Columbites epoch, so there is 

nothing improbable about it.

Meekoceras, Clypeoceras, Ophiceras, and Xenodiscus 

range through the entire Lower Triassic and are present 

in all the great regions. They are therefore not 

diagnostic as genera, although individual species are 

excellent index fossils.

Most of the other genera of the American Lower 

Triassic are limited in their geologic range, and some, 

such as Tirolites and Columbites, are zone markers.

Out of 32 genera of ammonoids in the Lower Triassic 

of North America 18 occur also in the Albanian fauna, 

and 16 in that of Timor, but only 9 are -common to 

all three regions, namely, Meekoceras, Clypeoceras, 

Ophiceras, Xenodiscus, Proptychites, Pledenstroemia, 

Anasibirites, Pseudosageceras, and Juvenites.

These geographic relationships are considered fully 

in the section on interregional correlation zones.

Species of the Meekoceras zone nearly related to Indian forms

Western America

Ophiceras sakuntala Diener _ _ = 

.Ophiceras dieneri Hyatt and

Smith.

Xenodiscus nivalis Diener- _ _ _ - : 

Xenodiscus rotula Waagen_-__ 

Flemingites aplanatus (White) _ 

Flemingites cirratus (White) _- 

Meekoceras arthaberi Smith.... 

Meekoceras gracilitatis White_ 

Meekoceras mushbachanum

White.

Meekoceras radiosum Waagen _; 

Meekoceras tuberculatum

Smith. 

Clypeoceras m u t h i a n u m

(Krafft). 

Anasibirites desertorum Smith _

Anasibirites cf. A. kingianus

(Waagen). 

Anasibirites angulosus

(Waagen). 

Anasibirites tenuistriatus

(Waagen).

Indian region

= Ophiceras sakuntala Diener. 

Ophiceras dcmissum Oppel.

= Xenodiscus nivalis Diener.

Xenodiscus rotula Waagen.

Flemingites rohilla Diener.

Flemingites salya Diener.

Meekoceras boreale Diener.

Meekoceras boreale Diener.

?Meekoceras cf. M. mush

bachanum. 

= Meekocerasradiosum Waagen.

Meekoceras fulguratum Waagen.

= Clypeoceras muthianum 

(Krafft).

Anasibirites tenuistriatus

Waagen.

?Anasibirites kingianus (Waagen).

Anasibirites. angulosus (Waagen).

Anasibirites tenuistriatus 

(Waagen).

1 Mojsisovics, E. von, Arktische Triasfaunen: Acad. imp. sci. St.-PCtersbourg 

Mem., ser. 7. vol. 33, No. 6, p. 73, pi. 11, figs. 18, a, b, 1886.
LOWER TRIASSIC FAUNAL ZONES OF NORTH AMERICA

Western A morion 

Anasibirites imiltiformis Welter.

Anasibirites lindgrcni Smith..._ 

Kas!i in i rites w a sat c h e n s i s

Mathews.

Goniodiscus typus Waagen._._ = 

Hedenstroeinia kossinati Hyatt and Smith. 

Inyoites oweni Hyatt and

Smith. 

Ussuria waageni

Smith. 

Aspenites acutus Hyatt and

Smith.

Aspenites laevis Welter._....__ 

Pseudosageceras multilobaturn

Noetling. 

Juvenites dieneri Hyatt and

Smith.

Juvenites sanctorum Smith. ... 

Owenites egrediens Welter.....

Indian region 

Anasibirites m u 11 i f o r m i s

Welter.

Anasibirites ibex Waagen. 

Kashmirites subarmatus Diener.

: Goniodiscus typus Waagen. 

Bedenstroemia mojsisovicsi

Diener. 

Inyoites discoidalis Welter.

Hvatt and Ussuria iwanowi Diener.

: Aspenites acutus Hyatt and

Smith.

: Aspenites laevis Welter. 

= Pseudosageceras multilobatum Noetling. 

Juvenites herberti Diener.

Juvenites medius Krafft. 

= Owenites egrediens Welter.

Species of the Columbites and Tirolites zones related to Mediterranean forms

Western America Mediterranean 

Columbites parisianus Hyatt Columbites dusmani Artand Smith. haber. 

Columbites spencei Smith _____ Columbites europaeus Arthaber. 

Tirolites harti Smith.________ Tirolites haueri Mojsisovics.

Tirolites knighti Smith--.---. Tirolites cassianus Quenstedt. 

Tirolites pealei Smith..-._____ Tirolites smiriagini Auerbach.

Tirolitos illyricus Mojsisovies.- = Tirolites illyricus Mojsisovics. 

Pseudharpoceras idahoense Pseudharpoceras praematurSinitli. um Arthaber. 

Pseudosageceras multilobatum Pseudosageceras drinense ArtNoetling. > haber.

Meekoceras sanctorum Smith. _ Meekoceras marginale Arthaber. 

Dalrnatites attenuatus Smith._ Dalmatites morlaccus Kittl.

Species of the Columbites and Tirolites zones related to 

Olenek forms

Western America Olenek

Ophiceras jacksoni Hyatt and "Xenodiscus" schmidti MojSmitli. sisovics.

Opliiceras 'spencei Hyatt and "Xenodiscus" euomphalus

Smith. Keyserling.

Meekoceras pilatum Hyatt and Meekoceras rotundatum MojSmith. sisovics.

Meekoceras micromphalus Meekoceras keyserlingi MojSmith. sisovics.

Meekoceras sanctorum Smith.. Meekoceras affine Mojsiso- 

	vics. 

Columbites ligatus Smith._ _ __ Columbites sp. indet.

LOWER TRIASSIC FAUNAL ZONES OF NORTH 

AMERICA

The Lower Trinssic ammonoids described in this 

report were collected in southeastern Idaho, in the 

Inyo Range of California, at the Phelan ranch in Elko 

County, Nev., and in the Wasatch Mountains of Utah. 

They occur in three paleontologic zones, named, in 

ascending order, the Meekoceras zone, Tirolites zone,

and Columbites zone. The geologic occurrence and 

characteristics of the faunas of these zones are briefly 

summarized on the following pages. Two older 

Lower Triassic faunal zones (the Otoceras and Genodiscus zones; see p. 13) have been discriminated in other 

parts of the world, but they have not been identified 

in North America.

MEEKOCERAS ZONE OF IDAHO

The Meekoceras-bea,ring beds, or Meekoceras zone, 

of Idaho corresponds faunally to the Hedenstroemia 

and Sibirites spiniger zones of the Himalayas and to 

the Flemingites, Owenites, and Anasibirites beds of the 

Salt Range of India, but the so-callecl Meekoceras 

beds of India are older and are not known to be represented by American cephalopod faunas. The Meekoceras zone of America was named and described first 

and of course will retain the name.

In this report three subzones are recognized within 

the Meekoceras zone. These subzones are here designated, in ascending order, Pseudosageceras multilobatum, Owenites, and Anasibirites subzones.

Although Pseudosageceras multilobatum is not restricted to the basal subzone of the Meekoceras-be&iing 

beds but has been identified as high in the section as 

the Columbites zone, it nevertheless has its greatest 

development in the basal part of the Meekoceras zone 

and is a world-wide and characteristic species at this 

horizon. The name is therefore here used as an interregional term for the basal subzone of the Meekoceras 

zone. In North America this subzone is characterized 

by the abundance of typical Meekoceras; by the relative abundance of Flemingites, Hedenstroemia, Xenodiscus, Ussuria, Pseudosageceras, Aspenites, Lanceolites, Paranannites, Cordillerites, Juvenites, Thermalites, 

and Dagnoceras; and by the first appearance in America 

of the interregional Asiatic species Pseudosageceras 

multilobatum, Aspenites acutus, A. laevis, and Clypeoceras muthianum. These species', together with the 

large number of species closely related to Indian forms 

but not quite identical, place the correlation of this 

fauna beyond question.

Although the rocks that mark this horizon are widely 

distributed in Idaho, Utah, western Wyoming, Nevada, 

and southeastern California, the best collections have 

been made in the Wasatch Mountains of southeastern 

Idaho.

The Pseudosageceras multilobatum subzone lies at the 

bottom of the Meekoceras zone and of the Thaynes 

group,2 and the principal collections were made in a 

layer of yellowish-gray and somewhat earthy limestone 

taken as the bottom of the Thaynes.

Locality 1 is in the SE. % sec. 36, T. 5 S., R. 43 E., 

1% miles west of old Williamsburg, in Grays Range,

2 Mansfield, O. R., Geography, geology, and mineral resources of part of southeastern Idaho: U. S. Oeol. Survey Prof. Paper 152, pp. 87-94, 1927.
8

about 5 miles southeast of John Grays Lake, Caribou 

County, Idaho. This is White's original locality I,3 

and the fossils from this horizon and locality are listed 

in column 1 of the accompanying table.

Locality 2 is in the SW. % sec. 20, T. 8 S.-, R. 44 E., 

on Schmid Ridge, IK miles east of the junction of 

Johnson and Slug Creeks, Caribou County, Idaho, 

about 14 miles northeast of Soda Springs. This was 

locality 2 of White. The fossils are listed in column 2 

of the table.

Locality 3 is in sec. 32, T. 8 S., R. 43 E., at the head 

of Wood Canyon, Aspen Range, Caribou County, 

Idaho, about 9 miles northeast of Soda Springs. The 

fossils are listed in column 3 of the table.

Locality 4 is in the NE. }{ sec. 9, T. 14 S., R. 43 E., 

at the south side of the mouth of Paris Canyon, about 

1 mile west of Paris, Bear Lake County, Idaho. The 

fossils are listed in column 4 of the table.

Locality 5 is in the SE. % sec. 13, T. 15 S., R. 44 E., 

about 1 mile northeast of Hot Springs, Bear Lake 

County, Idaho, at the northeast end of Bear Lake. 

The fossils are listed in column 5 of the table.

Mansfield 4 has recently published detailed maps 

and descriptions of the stratigraphy of the Thaynes 

group, and in order to avoid unnecessary repetition 

here the reader is referred to his excellent work for such 

details.

Locality 4, Paris Canyon, is the only place where the 

Pseudosageceras multilobatum and Anasibirites subzones of the Meekoceras zone and the Tirolites and 

Columbites zones were seen in sequence, and the two 

latter zones are not known to be fossiliferous anywhere 

else in the' region. The base of the Anasibirites subzone is poorly exposed a few feet above the Pseudosageceras multilobatum subzone on the south side of the 

canyon, on' Otto Rohner's ranch. Several hundred 

feet, possibly 200 or 300, is covered by soil and the 

valley alluvium. Then, on the north side of the canyon, the outcrops of the Tirolites zone are marked by 

gray shales about 50 feet thick, and the Columbites 

zone is about 30 feet higher in the section.

All these faunal horizons lie within the Thaynes 

group. They are not distinguished as units in the 

mapping but are easily separated paleontologically 

and are of nearly world-wide significance.

' White, C. A., Triassic fossils from southeastern Idaho: U. S. Geol. and Geog. 

Survey Terr. Twelfth Ann. Kept., pt. 1, pp. 105-118, 1880. 

< Mansfield, G. K., op. cit., pis. 1-9, pp. 81-96.

Fauna of the Pseudosageceras multilobatum subzone of southeastern

Idaho

[Species marked with an asterisk (*) occur also in the Oivenites subzone of Inyo 

County, Calif.]

*Lecanites arnoldi Hvatt and Smith

*Lecanites knechti Hvatt and Smith

Ophiceras dieneri Hvatt and Smith __

Xenodiscus cordilleramis Smith _

Xenodiscus gilberti Smith __ . _

Xenodiscus intermoutanus Smith ...

Xenodiscus tarpeyi Smith _ _ _ _

* Xenodiscus toulai Smith _ _

*Xenodiscus waageni Hvatt and 

Smith... .__________.__! . _

Xenodiscus whiteanus (Waagen)

*Meekoceras arthaberi Smith. ___

Meekoceras cristatum Smith ._

Meekoceras evausi Smith. ___

*Meekoceras gracilitatis White..

* Meekoceras mushbachanum White __ 

Meekoceras mushbachanum var. corrugatum Smith ___

Meekoceras patelliforme Smith _ _ _

Meekoceras sylvanum Smith.

Clypeoceras muthianum (Krafft) _ _

Dagnoceras bonnevillense Smith

Dagnoceras bridges! Smith

Dagnoceras havdeni Smith

Dagnoceras pealei Smith ___

*Flemingites aplanatus (White). ____

Flemingites aspenensis Smith _

Flemingites bannockensis Smith.

Flemingites cirratus (White) ______

Flemingites russelli Hvatt and Smith. 

Flemingites russelli Hyatt and Smith 

var. gracilis Smith _ _ ____

Hedenstroemia hyatti Smith.. _

*Hedenstroemia kossmati Hvatt and 

Smith. ._.______________:________

Dalmatites richardsi Smith. _ ____

Ussuria waageni Hvatt and Smith __

Cordillerites angulatus Hvatt and 

Smith.. ..____________._"__.______

*Lanceolites compactus Hyatt and 

Smith.... _ ____________________

* Aspenites acutus Hyatt and Smith. _ _ 

Aspenites laevis Welter. __ ____

*Pseudosageceras multilobatum Noetling--__________---_-_--_-----_-_

*Juvenites dieneri Hyatt and Smith __ 

Juvenites kraffti Smith . _ _

Juvenites sanctorum Smith _

Paranannites aspenensis Hvatt and 

Smith.. ..__ __________ "_ _______

Paranannites columbianus Smith

Paranannites compressus Smith_ ___

i

X

y

v

x

y

y

X

V

V

y

y

y

y

y

y

y

X

y

X

y

y

X 

X

X

X 

X

X

X

X

2

X

X

X

X

X

y

X

x

X

y

y

y

y

y

y

X

x

x

x

y

x

x

x

3

y

y

y

y

y

y

y

y

y

x

x

x

x

x 

y

y

y

y

y

y

y

y

y

x 

x

y

y

y

y

y

x

x

x

x

x

y

y

y

y

y

4

v

X

X

---

x

X

x

x"

y

5

v

X

X

v

X 

v

v

v

X

X

y

y

v

X

X

X

X

X

X

X

x

X

x

x

X

x

X

x

x

The characteristic species of the Pseudosageceras 

multilobatum subzone are listed in the table on page 1G.
LOWER TRIASSIC FAUNAL ZONES OF NORTH AMERICA 9

MEEKOCERAS ZONE OF CALIFORNIA

The Meekoceras zone of California is best known 

from the Inyo Range, on the east side of Owens Valley, 

IK miles east of the Union Spring, near the McAvoy 

trail over the Union Wash leading to Salinas Valley. 

This locality is about 15 miles southeast of Independence, Inyo County, Calif. The fossils were all 

found in a bed of gray limestone, not more than 12 

feet thick, that crops out on the south side of the canyon 

near the trail. In geologic horizon the beds at this 

locality are equivalent to the upper part of the Pseudosageceras multilobatum subzone and the overlying 

Owenites subzone of southeastern Idaho, the two not 

being separated lithologically at this place.

The Owenites subzone, as exposed here, is characterized by the continued abundance of typical Meekoceras, Aspenites, Lanceolites, and Pseudosageceras and 

by the first appearance of Owenites, Inyoites, Anasibirites, a,nd Sturia; also by the disappearance of typical 

Flemingites, Ussuria, and Cordillerites. The faunal 

association shows that this subzone corresponds to the 

Owenites subzone of the Phelan ranch, Elko County, 

Nov., and of Paris Canyon, Bear Lake County, Idaho.

The Owenites subzone has been differentiated outside 

of America only in Timor, where it was named 5 and 

where it is more sharply separated from the underlying 

Pseudosageceras zone and the overlying Anasibirites 

zone. It has not yet been segregated in the Himalayas 

and the Salt Range of India, where this part of the 

column is poorly represented. It occurs on Svalbard, 6 

where species indicative of this horizon have been 

listed, though not yet described and figured.7

Of this fauna, Owenites egrediens and Aspenites 

laevis occur in the Owenites zone of Timor; Inyoites is 

represented, in India and Timor by closely allied 

species; Anasibirites is represented in India and Timor 

in the Anasibirites zone by species nearly related. 

Lanceolites and Sturia are not yet known in the Indian 

region, but this lack is probably only temporary, for 

beds at this horizon are poorly developed in the places 

known there at present.

Fauna of the Owenites subzone of Inyo County, Calif.

[Spocios marked with an asterisk (*) occur also in the Pseudosageceras multilobalum 

subzone of southeastern Idaho]

*Lecanites arnoldi Hyatt and Smith.

*Lecanites knechti Hyatt and Smith. 

Ophiceras involutum Smith. 

Ophiceras parvuni Smith. 

Ophiceras sakuntala Diener. 

Ophiceras subquadratum Smith.

s Woltor, 0. A., Die Ammoniten der Unteren Trias vou Timor: Palaeontologie 

von Timor, Lief. 11, Abh. 19, p. SO, 1922.

0 The group of islands in the Arctic Ocean lying east of Greenland, which has 

heretofore been designated the Spitsbergen Archipelago, has been placed by treaty 

under the dominion of Norway, and the name has been changed by Norway to 

Svalbard. See U. S. Geographic Board Decisions, June 8, 1928.

' Spath, L. F., On ammonites from Spitsbergen: Geol. Mag., vol. 58, pp. 301-350, 

1921.

Xenodiscus marcoui Hj'att and Smith. 

Xenodiscus strongi Hyatt and Smith.

*Xenodiscus toulai Smith.

*Xenodiscus waageni Hyatt and Smith.

* Meekoceras arthaberi Smith.

*Meekoceras gracilitatis White.

*Meekoceras mushbachanum White. 

Meekoceras newberryi Smith. 

Meekoceras radiosum Waagen. 

Meekoceras strongi Smith. 

Meekoceras tuberculatum Smith. 

Clypeoceras hooveri Hyatt and Smith. 

Clypeoceras pusillum Smith.

*Flemingites aplanatus (White). 

Anasibirites desertorum Smith. 

Anasibirites lindgreni Smith. 

Anasibirites noetlingi Hyatt and Smith. 

Inyoites oweni Hyatt and Smith. 

Sturia compressa Hyatt and Smith. 

Sturia woodini Smith.

* Lanceolites compactus Hyatt and Smith. 

Lanceolites bicarinatus Smith.

*Aspenites acutus Hyatt and Smith.

*Pseudosageceras multilobatum Noetling.

*Hedenstroemia kossmati Hyatt and Smith. 

Owenites carpenteri Smith. 

Owenites koeneni Hyatt and Smith. 

Owenites egrediens Welter. 

Owenites zitteli Smith. 

Proptychites walcotti Hyatt and Smith.

*Juvenites dieneri Hyatt and Smith. 

Proteusites rotundas Smith. 

Prosphingites austini Hyatt and Smith.

The characteristic species of the Owenites subzone 

are listed in the table on page 16.

MEEKOCERAS ZONE OF PHELAN RANCH, ELKO COUNTY,

NEV.

About 70 miles south of Wells, 3 miles west of the 

Phelan ranch, near the mouth of Cottonwood Canyon, 

on the east side of the Ruby Range, about 50 feet of 

sandy reddish-brown limestone, impregnated with iron, 

is exposed. The dip is low, to the east, away from the 

range, and the Meekoceras zone lies with an apparent 

unconformity upon the massive gray Pennsylvanian 

limestone.

Fossils are abundant but poorly preserved in the 

Meekoceras zone of this region. The locality was discovered by Oscar H. Hershey in 1905, and visited by 

the writer in 1911. The joint collections yielded the 

following species:

Fauna of the Meekoceras zone of Phelan ranch, Elko County, Nev.

[Species marked with an asterisk (*) occur also in the Pseudosageceras multilobatum 

subzone of southeastern Idaho; those marked with a dagger (t) occur also in the 

Owenites subzone of Union Wash, Inyo Mountains, Calif.]

*fLecanites arnoldi Hyatt and Smith.

*fLecanites knechti Hyatt and Smith. 

fOphiceras sakuntala Diener. 

Xenodiscus nevadanus Smith. 

Xenodiscus nivalis Diener.

*tMeekoceras gracilitatis White.

*fMeekoceras cf. M. mushbachanun White, 

fMeekoceras cf. M. radiosum Waagen.
10 LOWER TRIASSIC AMMONOIDS OF NORTH AMERICA

Dalmatites attenuatus Smith, 

flnyoites oweni Hyatt and Smith. 

fAnasibirites desertorum Smith.

*fPseudosageceras multilobatum Noetling.

*fAspenites acutus Hyatt and Smith. 

fLanceolites bicarinatus Smith. 

fOwenites cf. O. koeneni Hyatt and Smith.

*fJuvenites dieneri Hyatt and Smith. 

*Paranannites aspenensis Hyatt and Smith.

The relationship of this fauna with the fauna of the 

Inyo Mountains of California is obviously closer than 

with the fauna of southeastern Idaho. However, it is 

intermediate between the two in affinities as in geographic position, being about 300 miles from each.

The horizon of the Nevada locality is probably at the 

base of the Owenites subzone of the Meekoceras zone.

FAUNA OF OWENITES SUBZONE OF SOUTHEASTERN IDAHO

At the mouth of Paris Canyon, 1 mile west of Paris, 

Bear Lake County, Idaho, in the upper part of the 

Meekoceras zone, are some obscure outcrops with a 

fauna slightly different from that of the Pseudosageceras 

multilobatum subzone. The fossils found here were 

few in number and poorly preserved, but they correspond to those of the Owenites subzone as developed in 

the Inyo Mountains of California and at the Phelan 

ranch on the east side of the Ruby Range in Nevada. 

The species identified from this horizon were as follows:

Anasibirites desertorum Smith.

Anasibirites lindgreni Smith.

Goniodiscus typus Waagen.

Lanceolites compactus Hyatt and Smith.

Aspenites acutus Hyatt and Smith.

Pseudosageceras multilobatum Noetling.

Juvenites kraffti Smith.

Paranannites aspenensis Hyatt and Smith.

Inyoites cf. I. oweni Hyatt and Smith.

Owenites cf. 0. koeneni Hyatt and Smith.

FAUNA OF ANASIBIRITES SUBZONE OF UTAH

The Anasibirites faunal zone was first distinguished 

in the Salt Range of India, where Waagen 8 called it 

"the Upper Ceratite limestone" and assigned it to 

the Middle Triassic. Later studies in India by Von 

Krafft and Diener 9 have shown that this zone belongs 

to the Lower Triassic and occurs in the Himalayas 

immediately above the Hedenstroemia beds, the Owenites 

subzone either being absent or not recognized. Later 

the presence of the Anasibirites faunal zone in Svalbard was recorded by Spath 10 from the "lowest nodule 

beds "with Keyserlingites, Goniodiscus, and other forms. 

Still later this faunal zone was differentiated and fully 

described from Timor by Welter, 11 who published a

8 Waagen, W., Fossils from the Ceratite formation: India Geol. Survey Mem., 

Palaeontologia Indica, 13th ser., Salt Range fossils, vol. 2, p. 3,1895.

9 Diener, Carl, The Trias of the Himalayas: India Geol. Survey Mem., vol. 36, 

pt. 3, pp. 33-35, 1912.

10 Spath, L. F., On ammonites from Spitsbergen: Geol. Mag., vol. 58, pp. 301. 

350, 1921.

11 Welter, O. A., Die Ammoniten der Unteren Trias von Timor: Palaeontologie 

von Timor, Lief. 11, Abh. 19, 1922.

great number of diagnostic species. The zone has 

also been discovered and collections have been made 

from it in the Wasatch Mountains of Utah by Math- 1 

ews, 12 who has identified a rich fauna closely allied 

to that of the Salt Range and of Timor.

The writer has had for study the collections of the 

Brouwer expedition to Timor and has found in them 

a far richer fauna of the Anasibirites zone than has 

ever been seen before, with nearly all of Waagen's 

species of this genus and a great many more in a wonderful state of preservation. These collections contain 

a very complete representation of the Lower Triassic 

faunal zones, with a few species identical with those 

from America and many closely related. A full 

discussion of the interregional relationships is given 

in the section on interregional correlation zones of the 

Lower Triassic.

The Anasibirites zone in Utah has yielded the following species:

Pseudosageceras multilobatum Noetling.

Cordillerites compressus Mathews.

Xenodiscus rotula Waagen.

Xenodiscus nivalis Diener.

Meekoceras davisi Mathews.

Anasibirites angulosus (Waagen).

Anasibirites bastini (Mathews).

Anasibirite? emmonsi Mathews.

Anasibirites hircinus (Waagen).

Anasibirites kingianus (Waagen).

Anasibirites kingianus (Waagen) var. inaequicostatus

Waagen.

Anasibirites mojsisovicsi Mathews. 

Anasibirites multiformis Welter.

Anasibirites multiformis (Welter) var. hyatti Mathews. 

Anasibirites tenuistriatus Waagen. 

Goniodiscus ornatus Mathews. 

Goniodiscus smithi (Mathews). 

Goniodiscus typus Waagen. 

Goniodiscus utahensis Mathews. 

Kashmirites meeki (Mathews). 

Kashmirites perrini (Mathews). 

Kashmirites resseri Mathews. 

Kashmirites seerleyi (Mathews). 

Kashmirites subarmatus Diener. 

Kashmirites wasatchensis Mathews.

TIROLITES ZONE

The Tirolites zone is well known at but a single 

place in Paris Canyon, \% miles west of Paris, Bear 

Lake County, Idaho where it lies about 225 feet 

above the Meekoceras zone and about 30 feet below 

the Columbites zone. The fossils are few, poorly 

preserved, and confined to a bed of gray shale from 

30 to 50 feet thick. Tirolites constitutes the most 

abundant and characteristic element of the fauna, 

with species closely allied with those of the Campil 

beds of the Tyrol, giving a definite correlation and 

marking the first appearance of Mediterranean types 

in the American Lower Triassic.

12 Mathews, A. A. L., The Lower Triassic cephalopod fauna of the Fort Douglas 

area, Utah: Walker Mus. Mem., vol. 1, No. 1, 1929.
LOWER TRIASSIC INTERREGIONAL CORRELATION ZONES 11

This faunal zone is not known in India, although 

Tirolites has been cited erroneously from both India 

and Timor.

Fauna of the Tirolites zone of Paris Canyon, southeastern Idaho

Dalmatites attenuatus Smith.

TiroJites liarti Smith.

Tirolites knighti Smith.

Tirolites pealei Smith.

Nautilus sp. indet.

Orthoceras sp. indet.

Pseudomonotis idahoensis White.

Pseudomonotis pealei White.

Pugnoides triassicus Girty.

Pentacrinus (Isocrinus) smith! Clark and Twitchell.

COLUMBITES ZONE

The Columbites faunal zone is known to be abundantly fossiliferous at only one place in America in 

Paris Canyon, VA miles west of Paris, Bear Lake 

County, Idaho. It lies about 30 feet above the 

Tirolites zone, which crops out in the same canyon. 

All the fossils were found in a bituminous layer of 

brown limestone, not over 6 inches thick. It is well 

down below the middle of the Thaynes group and 

should be found elsewhere in the Wasatch Mountains.

The Columbites fauna of Idaho is most closely related to that of Albania, 13 where Arthaber has described many kindred species; also to the LeiophylHtes 

fauna of India and Timor. It is also distinctly correlative with the Olenek fauna of northern Siberia, 14 

where several forms related to those of Idaho are 

found.

The Columbites zone is one of the most definite and 

satisfactory interregional correlation zones in the whole 

Mesozoic and has been of great use in determining the 

true stratigraphic succession in the Triassic of India, 

Timor, Siberia, and even the classic Mediterranean 

region. The characteristic genus Columbites is certainly not indigenous in either Idaho or Albania but 

is an immigrant into both regions from some outside 

source, which was probably the boreal region.

Fauna of the Columbites zone of Paris Canyon, southeastern Idaho

Ophiceras jacksoni Hyatt and Smith. 

Ophiceras spencei Hyatt and Smith. 

Meekoceras curticostatum Smith. 

Meekoceras micromphalus Smith. 

Meekoceras pilatum Hyatt and Smith. 

Meekoceras sanctorum Smith. 

Pseudharpoceras idahoense Smith. 

Tirolites cf. T. illyricus Mojsisovics. 

Pseudosageceras multilobatum Noetling. 

Celtites apostolicus Smith. 

Celtites planovolvis Smith.

u Artlmber, 0. von, Dio Trias von Albanien: Beitr. Paliontologie Oesterr - 

Unganis li. dos Orients, Band 24, pp. 169-276, 1911.

'< Mojsisovics, 15. von, Arktische Triasfaunen: BeitrSge zur palflontologischen 

Clmrnctotistik dor arktiseh-paciflschon Triasprovinz: Acad. imp. sci. St.-P6tersbourg Mem., 7th sor., vol. 33, No. 6, pp. 1-159, 1886.

67664 32 2

Celtites ursensis Smith. 

Columbites consanguineus Smith. 

Columbites ligatus Smith. 

Columbites minimus Smith. 

Columbites ornatus Smith. 

Columbites parisianus Hyatt and Smith. 

Columbites spencei Smith. 

Nautilus (Pleuronautilus) sp. indet. 

Orthoceras sp. indet. 

Cosmacanthus elegans Evans.

HISTORICAL SUMMARY

The Lower Triassic faunas have become known 

largely in the last 40 years. As they were found and 

described piecemeal in widely separated parts of the 

world, a great deal of confusion has resulted in their 

correlation, and a great deal has been written about 

the faunal and physical geography of the Lower 

Triassic that must be revised in the light of later 

discoveries.

For many years the writer has been collecting and 

studying the Lower Triassic faunas of North America 

and has also had for study the Lower Triassic ammonites of Timor, in the East Indies. He has now completed papers on these two faunas. These collections 

have thrown much light on the occurrence of interregional species and interregional zones.

In the past faunas that were not contemporaneous 

have been compared and contrasted with each other, 

and erroneous conclusions have been drawn as to 

separation of regions. There has also been much controversy as to whether certain faunas should be assigned to the Permian or to the Lower Triassic; it has 

also been debated rather acrimoniously whether certain 

faunas should be placed in the upper part of the Lower 

Triassic or in the lower part of the Middle Triassic.

As all these debatable faunas have been found in 

regions remote from European centers, it has been 

difficult to assemble collections satisfactory for accurate classification and discussion. Little by little the 

gaps have been filled out, and our knowledge of faunal 

zones in the Lower Triassic has become nearly as 

complete as it is of those in the Jurassic.

For nearly 50 years the relations of Triassic cephalopod genera to those of the Paleozoic have been a 

favorite field of study, as shown in the works of Branco, 

Hyatt, Karpinsky, Mojsisovics, Haug, Diener, Arthaber, Frech, and others. The lack of agreement 

between these investigators shows how d'fficult is the 

field, and how, with nearly the same premises, careful, 

observers can come to very different conclusions. It 

becomes clear that the conclusions of these writers as 

to genetic relationships of the forms discussed are not 

facts but rather scientific interpretations of observed 

facts a distinction not always easy to keep in mind.
12 LOWER TRIASSIC AMMONO1DS OF NORTH AMERICA

In the field of phylogeny of ammonoids every investigator must pay constant and reverent tribute to the 

three masters and pioneers Alpheus Hyatt, W. 

Branco, and A. Karpinsky. These leaders have blazed 

the way for all to follow. We can not always step in 

their steps nor would they wish us to be slavish 

imitators but we know that they were headed in the 

right direction, even though they may at times have 

strayed from the main path. It is a great advantage 

to this branch of biology that three men of such keen 

observation and far-seeing interpretation have set the 

pace.

Naturalists have sought for genetic series since the 

days of Darwin and have found a few, more or less 

convincing. But most of them are badly broken or 

are too short. It has been reserved for the Cephalopoda to give us genetic lines running unbroken from 

the Devonian to the end of the Cretaceous, checked 

at intervals by ontogenic series recapitulating at least 

part of the previous history. Compared with this the 

famous genealogy of the horse from the Eocene to the 

present is but ephemeral contemporary history. One 

may surely pardon the exuberant enthusiasm and 

confidence of students of ammonoid phylogeny, even 

while one smiles at some of the results. It is a big 

field, and there has not yet been enough time to 

thresh out the grain from the chaff. There is plenty 

of both, and the contemporary can not always distinguish the one from the other.

It must not be inferred from the writer's lack of 

agreement with many of the conclusions of other workers in the same field that he is moved by any personal 

bias or lack of appreciation of their high attainments in 

contributions to science. On the contrary, he stands 

on terms of cordial friendship with those with whom 

he has come into contact by personal association or 

correspondence. Also he feels the most sincere admiration for the publications of those with whom he 

is forced to disagree most frequently. But each contributor must state the case as he sees it, regardless of 

personal friendship for the living or of reverence for 

the honored dead. Otherwise there would be no 

 progress.

These differences of opinion in biostratigraphy and 

in ammonoid phylogeny make the subject all the more 

interesting, for they show that this branch of science 

is still in the making and is far from being cut and 

dried. As a basis of phylogenetic study an accurate 

determination of successive faunal zones, especially of 

interregional zones, is indispensable. The smaller the 

.unit that can actually be determined the more definite 

the correlations, and thus the more definite the data 

concerning occurrence of critical genera and species.

Fortunately the entire Triassic has been studied 

intensively in many parts of the world, and widespread faunal zones have been definitely established.

This is especially true of the Lower Triassic, where five 

distinct zones may be recognized and correlated with 

considerable certainty, notably in the regions bordering 

on the Pacific Ocean. This success has been made 

possible by the explorations of many geologists in 

India, Madagascar, Timor, Siberia, and western 

America. Some of these explorers gave their lives in 

this work, and many gave their health. To them 

should be given all honor, for they were truly martyrs. 

They have left an imperishable monument in collections 

gathered and in notable publications on stratigraphy 

and the faunas collected by them. India has been in 

the front rank in the production of a noble array of 

monographs, but Austria, Holland, Russia, Germany, 

Italy, France, and America have each contributed a 

fair share to advancement of knowledge of this subject.

Diener 15 has given a very complete and satisfactory 

critical compilation of the distribution and correlation 

of Triassic faunas of the whole world, as they were 

known and interpreted in 1915. Fifteen years of 

study and exploration by many naturalists since that 

time have added much to our knowledge of geographic 

and zonal distribution of Triassic faunas and have 

necessitated some revision of their correlations. The 

present chapter is an attempt at such a revision, and 

the writer wishes here to make the fullest acknowledgment of indebtedness to the researches of Mojsisovics, 

Waagen, Frech, Noetling, Koken, Krafft, and Diener, 

on the Triassic of India; of Diener, Welter, Krumbeck, 

Arthaber, and Wanner on the Triassic of the Malay 

Archipelago; of Mojsisovics, Hauer, Toula, Diener, 

Laube, Arthaber, Renz, and Kittl on the Mediterranean province; of Mojsisovics, Boehm, Diener, and 

Spath on the Arctic region; and of Meek, White, and 

Hyatt on the American region. Without these brilliant 

contributions to ancient faunal geography no comparative study would be possible.

The writer especially wishes to express his debt to the 

classic monographs of Mojsisovics, the great master of 

Triassic paleontology, and to those of Diener, who, at 

the time of his death, was the honored dean and 

acknowledged leader of writers in this field. To them 

every student of Triassic paleontology turns for inspiration and guidance.

It will be seen that in the study of Lower Triassic 

stratigraphy we have long passed the stage of Quenstedt's local faunal units limited by lithology; that we 

have reached the stage of Oppel's formulation of interregional zones characterized by faunas dispersed and 

limited by geographic conditions; but that we have not 

yet entered the stage of Buckman's attempt at subdivision of biologic units into hemerae. Nor are we likely 

to enter that phase for some time to come, for even the 

partial success of such an attempt depends upon the

's Diener, Carl, Die marinen Reiche der Triasperiode: K. Akad. Wiss. Wien 

Denkschr., Band 92, 1916.
LOWER TRIASSIC INTERREGIONAL CORRELATION ZONES 13

occurrence of fossil beds in easily accessible regions, 

with numerous local collectors. The good Lower 

Triassic faunas occur only in widely separated regions, 

all remote from centers of research, accessible only to 

the explorer, and usually not capable of intense local 

subdivision. It is also doubtful whether we shall ever 

have the data, either in maps or in collections of fossils, 

for such an attempt. In the meantime we may well 

give thanks for such knowledge as we have of the 

subject, for to acquire even that has required unremitting toil and arduous travel of geologic explorers for 

three-quarters of a century.

GEOGRAPHIC DISTRIBUTION OF LOWER TRIASSIC 

INTERREGIONAL ZONES

The geographic distribution of the Lower Triassic 

faunal zones of the world is shown on the map (fig. 1) 

and in the correlation chart facing page 14 and is 

briefly summarized below:

I. Otoceras /one. Known in the Himalayas of India as the 

Otoceras beds, near Lilang, in Spiti, and at the 

Shalshal Cliff near Rimkin Paiar, in Painkhanda.

II. Genodiscus zone. (See p. 15.) Known in the Salt Range 

of India as Lower Ceratite limestone; in the 

Himalayas as the so-called Meekoceras beds; in 

Timor as the Opliiceras beds; in Madagascar 

and at Ussuri Bay as the so-called Meekoceras 

beds; and probably in eastern Greenland. It is 

absent or unknown in the Arctic, Mediterranean, and western American regions.

III. Meekoceras zone. Subdivided into the Pseudosageceras 

muliilobatum, Owenites, and Anasibirites subzones.

Ilia. Pseudosageceras multilobatum subzone. Practically worldwide. Known in the Salt Range of India as 

Flemingites beds or Ceratite marls and Ceratite 

sandstone; in the Himalayas as the Hedenstroemia beds; in Timor as the Flemingites beds 

or Pseudosageceras zone; at Ussuri Bay; in Madagascar; in Svalbard as the lower part of the 

Posidonomya beds; on the Caspian Sea as the 

Paratirolites beds; in Idaho and California as 

the Pseudosageceras muliilobatum subzone. It 

is the first truly interregional zone of the Lower 

Triassic, widespread from the Indian Ocean to 

the Arctic and down to western America.

Illb. Owenites subzone. Distinguished in Timor, Svalbard, 

Idaho, California, and Nevada.

IIIc. Anasibirites subzone. Known in the Salt Range as the 

Upper Ceratite limestone or Anasibirites beds; 

in the Himalayas as zone of "Sibirites" sj)iniger; in Timor as the Anasibirites beds; in Japan, 

as the Meekoceras beds; in Svalbard as the socalled Flemingites zone; in California, Utah, 

and Idaho as the upper subzone of the Meekoceras zone.

IV. Tirolites zone. Confined to the Mediterranean and the 

western American regions.

V. Colunibites zone. Known in Albania and in Idaho as the 

Columbites zone; on the Olenek River, in Siberia, as the Olenek horizon; in Timor as the 

Leiophylliles beds; and doubtfully in the Himalayas as the "zone of Rhynchonella griesbachi" 

of the so-called "Lower Muschelkalk."
14 LOWER TRIASSIC AMMONO1DS OF NORTH AMERICA

FIGURE 1. Map showing geographic distribution of Lower Triassie faunas.

I. Otoceras fauna.

II. Genodiscus fauna. 

Ilia. Pseudosageceras multilobatum fauna. 

lllb. Oweniles fauna, 

lllc. Anasibirites fauna. ) 

IV. Tirolites fauna. 

V. Cniumbiles fauna. 

Locality:

1. Tyrol; fauna IV.

2. Albania; fauna V.

3. Djulfa, on the Caspian Sea; fauna Ilia.

4. Salt Range of India; faunas II-IIlc and V?

III. Meekoceras fauna.

Locality Continued.

5. Himalayas of India; faunas 1-IIlc and V?

6. Madagascar; faunas 11-lIIa.

7. Timor; faunas II-V.

8. Svalbard; faunas Illa-IIIc, and V?

9. Olenek River, Siberia; fauna V.

10. Ussuri Bay, eastern Siberia; faunas II-III.

11. California; faunas Illa-IIIc.

12. Nevada; faunas Illb-IIIc.

13. Idaho; faunas Illa-IIIc, IV, and V.

14. Utah; fauna IIIc.
Correlation table of lower Triassic faunas

V. Columbites zone

IV. Tirolites zone

^ Q IIIc. Anasibirites subzone

|^ ^ Illb. Owenites subzone

B w Ilia. Pseudosageceras multilobatum subzone

II. Genodiscus zone

I. Otoceras zone

Campil beds with Tirolites

Columbites fauna

Salt Range

Pseudharpoceras beds

Upper Ceratite limestone 

or Anasibirites beds

Absent or not recognized

Ceratite sandstone, or 

Flemingites beds

Lower Ceratite limestone 

or so-called Meekoceras 

beds

India

Himalayas

Leiophyllites beds with Rhynchonella griesbachi

Zone of "Sibirites" spiniger

Absent or not recognized

Hedenstroemia beds or zone of 

Flemingites rohilla

So-called Meekoceras beds

Otoceras beds

Leiophyllites fauna

Anasibirites beds

Owenites beds

Flemingites beds or Pseudosageceras zone

Ophiceras beds

<?)

So-called Meekoceras beds

Keyserlingites fauna

Anasibirites beds (so-called 

"Flemingites zone")

Beds with Inyoites

Represented in lower part 

of Posidonomya beds

Keyserlingites fauna

<?>

So-called Meekoceras beds

Western America

Columbites zone

Tirolites zone of Idaho

2 Anasibirites subzone

a

g 0) 

® § Owenites subzone

!£3 Pseudosageceras multilobatum 

subzone

Not identified

Not identified

67664 32. (Face p. 14.)
LOWER TRIASSIC INTERREGIONAL CORRELATION ZONES 15

GENERAL CHARACTERS OF THE LOWER TRIASSIC 

AMMONOID FAUNAS

OTOCERAS ZONE

The Otoceras zone contains, as characteristic fossils, 

Otoceras woodwardi Griesbach, Ophiceras sakuntala 

Diener, 0. tibeticum Griesbach, 0. demissum Oppel, 

Proptychites scheibleri Diener, Prosphingites nala 

Diener, Xenodiscus himalayanus Griesbach, and Episageceras dalailamae Diener. This horizon was assigned by Griesbach, Waagen, Mojsisovics, Diener, 

and Bittner to the Lower Triassic and by Noetling, 

Kraff't, and Frech to the Permian.

The evidence as to the Lower Triassic age of the 

Otoceras fauna brought forward by Diener 16 is complete 

and most convincing. No further references will be 

given here, for Diener's paper is easily accessible and 

has a full bibliography.

This fauna is characterized by the flaring up of the 

M!eekoceratidae from Xenodiscus, by the abundance 

of Ophiceras and Otoceras, and by the reappearance 

of Arcestidae in Prosphingites. It is entirely confined 

to the Indian region.

GENODISCUS ZONE

The zone here called the Genodiscus zone has been 

called in. India the Meekoceras zone, but that name is 

a misnomer, for it was preoccupied by Peale l7 in designating a younger faunal zone in Idaho that is the 

equivalent of the Flemingites and Hedenstroemia beds 

of Timor and the Himalayas. It is therefore -here 

called after the most characteristic element of the 

fauna from the subgeneric title applied to the group 

of "Celtites" radiosus and "C.fortis" ( = C. lidacensis].

Characteristic species of this zone are Genodiscus 

radiosus Krafl't, G. lidacensis Welter, Meekoceras discoides Waagen, M. markhami Diener, Clypeoceras 

spitiense Krafl't, C. brouweri Smith, Xenodiscus rotula 

Waagen, X. radians Waagen, Hedenstroemia lila?igensis 

Krafft, and Ophiceras tibeticum Griesbach.

This fauna is distinguished by the development of 

Xenodiscus into Genodiscus, the forerunner of Anasibirites and thus the probable ancestor of many of the 

group of Ceratitoidea, and also by the continued filiation of Meekoceras into its various branches. This 

fauna is still almost entirely confined to the IndoPacific region.

MEEKOCERAS ZONE

Pseudosageceras multilobatum subzone. In the Salt 

.Range of India the zone here called Pscudovageceras 

multilobatum sub/one is known, as the Flemingites 

beds or Ceratite sandstone; in the Himalayas as Heden1(1 Dionor, Ctvrl, Tho Triassic of the Himalayas: India Oeol. Survey Mem., vol. 

30, pt. 3, pp. 42-55, 1012.

17 Pealo, A. C., Report, on the geology of the Green ttiver district: U. S. Oeol. and 

Goog. Survey Terr. Eleventh Ann. Rcpt, pp. 612, 622-628, 1879.

stroemia beds or zone of Flemingites rohilla; in Timor 

as the Flemingites beds; on the Caspian Sea as the 

Paratirolitesbeds; in Madagascar it is probably represented in the tipper part of the so-called Meekoceras 

beds; at Ussuri'Bay,-in eastern Siberia, probably by 

the same horizon; in Svalbard it is represented in the 

lower part of ih&Posidonomya beds; in western America 

it comprises the lower and main part of the Meekoceras 

zone as originally named by Peale. This subzone is 

characterized by the great development of Pseudosageceras, Ussuria, Flemingites, Hedenstroemia, Meekoceras, and Clypeoceras. It is the first great world-wide 

zone of the Lower'Triassic, characterized especially by 

Pseudosageceras multilobatum, Xenodiscus nivalis, and 

the giant Flemingites. It should not be called the 

Flemingites zone, nor the Hedenstroemia zone, as these 

genera are not confined to this horizon, nor are they 

common outside the Indian region. It might 

better be named after the most widely distributed 

characteristic species the zone of Pseudosageceras 

multilobatum, and it is so designated in this report. 

This species is fairly common in India, Timor, and 

western America (Idaho, Nevada, California), associated in all these regions with nearly related and 

commonly identical species. This is the widest 

distribution of a definite and restricted fauna in the 

Lower Triassic, though the term Meekoceras zone has 

been misapplied in regions outside of America, so that 

in the past it has meant different things in different 

regions.

The Hedenstroemia fauna of the Himalayas has been 

regarded by Diener 1S as the top of the Lower Triassic 

and the equivalent of the Olenek beds of Siberia and 

of the Columbites fauna of Albania. But in the Himalayas the Anasibirites beds occur above the Hedenstroemia zone and agree in position and fauna with the 

Upper Ceratite limestone or Anasibirites beds of the 

Salt Range, which, in Idaho lie between the Hedenstroemia and Columbites horizons. The succession in 

the Salt Range of India and in Idaho is clear and 

unmistakable and shows two distinct zones above the 

Hedenstroemia or Flemingites faunal zone and still 

certainly of Lower Triassic age. Thus the Pseudosageceras multilobatum subzone is really not very 

much higher than the middle of the Lower Triassic.

This zone is characterized by the great development 

of the so-called "Beloceratea" (Pseudosageceras, 

Aspenites, Lanceolites, Cordillerites, and Ussuria}; by 

the rapid branching out of the Meekoceras stock into 

many subgenera and new genera, including Hedenstroemia; by the rapid rise of Flemingites from the older 

Ophiceras; and by the rapid development of Nannitidae into Paranannites and Thermalites, probable 

forerunners of Ptychitidae and Haloritidae.

15 Diener, Carl, Trias of the Himalayas: Geol. Survey Mem. India, vol. 36, pt. 3, 

pp. 36-42, 1912.
16 LOWER TRIASSIC AMMONOIDS OF NORTH AMERICA

The time of the Pseudosageceras multilobatum subzone was characterized by the radial migration out of 

the Indian Ocean northward to the Arctic Ocean, 

southward to the East Indian Archipelago, Timor, and 

Madagascar, eastward to Ussuri Bay on the Siberian 

coast, and around the ancient shore line of the north 

Pacific to the Cordilleran Sea of California, Nevada, 

and Idaho. It must have been an epoch'of exceedingly 

uniform climate and favorable conditions to allow this 

widespread migration with so little generic or specific 

change, when species could range more than halfway 

around the earth and from 10° S. to 80° N. and still be 

almost identical.

But some sort of barrier obstructed the way into 

the Mediterranean, for there this fauna is still unknown. The portal of Asia Minor was still closed, and 

it did not open until the Tirolites epoch.

Of course there were plenty of local differences between the faunal regions that did show connection, but 

they were not greater than can easily be explained by 

the wide separation of these regions: they do not imply 

actual isolation. Only the more hardy species could 

possibly make the long journeys from one region to 

another, but the fact remains that some did make 

them unchanged, whereas others were slightly modified 

on the way. Still others were stay at homes, remaining 

in the regions where they were developed. A comparative study of these three groups of forms makes 

possible a discrimination of ancient faunal regions.

Characteristic species of the Pseudosageceras multilobatum subzone of the Meekoceras zone

Pseudosageceras multilobatum Noetling

sp. indet. Diener___ _ _ _ _

Ussuria iwanowi Diener. _ _ - _ _

waageni Hvatt and Smith __ ' Aspenites acutus Hvatt and Smith

Lanceolites compactus Hvatt and Smith. _ ___

Cordillerites angulatus Hyatt and Smith..

Flemingites compressus (White) _ _

cirratus (White) _

aplanatus (White) - _ _ '

Meekoceras gracilitatis White. .

mushbachanum White __ _

Paranannites aspenensis Hvatt and Smith

Hedenstroemia kossmati Hvatt and Smith _ _

Svalbard

(?)

(?)

Olenek

X?

India

Himalayas

X

X

X 

X

(X)

X

Salt 

Range

X

X

Timor

X

X

X

X

(?)

X 

X

,

I

Ussuri

X

X

X

Idaho

X

X

X 

X 

X

X 

X

X 

X 

X

X 

X

California and 

Nevada

X

X 

X

X

X 

X

X

Owenites subzone. The characteristic genera of the Owenites subzone are Owenites and Inyoites. 

characteristic species are listed below:

Characteristic species of the Owenites subzone of the Meekoceras zone

The

Owenites egrediens Welter . __.__ _ __ ____

simplex Welter

koeneni Hyatt and Smith __ _

Invoites oweni Hyatt and Smith . _ ______ _____

kashmiricus Diener _ ___

Albania

X

Svalbard

(?)

India

Himalayas

X 

X 

X

X

X

Salt 

Range

X

X

Timor

X 

X

(?)

X 

X 

X 

X 

X 

X

(?)

X

X

Idaho

X 

X

California and 

Nevada

X 

X 

X 

X

X

X

X
LOWER TRIASSIC INTERREGIONAL CORRELATION ZONES 17

Anasibirites subzone. The Anasibirites subzone is 

characterized by the abundance of Anasibirites, 

Stephanites, and Prionites, by the radiation outward 

from the East Indian Archipelago, and by the identity, 

or near identity, of species in widely separated regions. 

It was first definitely recognized in the Salt Range of 

India, where Waagen 19 called it the Upper Ceratite 

limestone. It is also present in Svalbard, as described by Spath 20 in a preliminary paper. It is 

present in southeastern Idaho, California, and Nevada, 

where Hyatt and the writer 21 have recognized elements of this fauna in the upper part of the Meekoceras 

zone. It has since been found by A. A. L. Mathews 

in the Wasatch Mountains of Utah. It has also been 

found by Welter 22 to be well developed in Timor, where 

he \vas able to separate it into two subzones, an upper 

(IIIc of the present report) or Anasibirites subzone 

in a strict sense and a lower (Illb of the present report) 

or Owenites subzone. This subdivision can be carried 

out with less certainty in Utah and California, where 

both those subzones seem to be best treated as parts 

of the Meekoceras zone. The Anasibirites fauna has 

been discovered in Japan, 23 where it was called the 

Meekoceras zone.

In the Himalayas of India the Anasibirites zone was 

discovered after the time of Waagen, and though the 

species were few it was definitely correlated with the 

Upper Ceratite limestone of the Salt Range, which

18 Waagon, \\'., Fossils from the Ceratite formation: India Oeol. Survey Mem., 

Palacontologia Inclica, 13th ser., Salt Range fossils, vol. 2, p. 3, 1895.

8n Spath, L. F., On ammonites from Spitsbergen: Oeol. Mag., vol. 58, pp. 297-305, 

347-350, 11)21.

21 llyatt, Alpheus, and Smith, J. P., The Triassic cephalopod genera of America: 

U. S. Geol. Survey Prof. Paper 40, pp. 48-49. 1905.

22 Woltor, 0. A., Die Ammoniten dor Unteren Trias von Timor: Palaeontologie 

von Timor, Lief. 11, Abli. 19, 1922.

23 Yohara, S., The Lower Triassic cephalopod and bivalve fauna of Shikoku: 

Japanese Jour. 0oology and Ocogiaphy, vol. 5, No. 4, 1927.

had been assigned by Waagen 24 to the Middle Triassic. 

The beds in Svalbard were also placed by Mojsisovics 25 

in the Muschelkalk. But there can now be no doubt 

that this faunal zone in both regions belongs to the 

Lower Triassic and is not even the top of that division, 

for in Idaho the Columbites zone lies about 300 feet 

higher in the same continuous section, and in the Salt 

Range, and somewhat doubtfully in the Himalayas 

of India, the equivalents of the Columbites zone lie 

above the Anasibirites zone. The same thing is probably true in Timor, but there the actual stratigraphic 

sequence is not known, because of the occurrence of 

the beds in isolated blocks, where the stratigraphy can 

only be inferred from the faunas.

Diener 26 accepts the zone of "Sibirites" spiniger 

in the Himalayas as the equivalent of the Upper Ceratite limestone of the Salt Range. But in the same 

chapter he correlates the Hedenstroemia beds of the 

Himalayas with the Columbites zone of Idaho and Albania. Now in Idaho the Columbites zone lies about 

300 feet above the Anasibirites laj^er, which is at .the 

top of the Meekoceras zone of that region, and the 

Meekoceras zone contains a rich fauna, consisting of 

Pseudosayeceras multilobatum, with Flemingites, Xenodiscus, Meekoceras, Pledenstroemia, and others, all 

closely related to forms in the Pledenstroemia beds of 

India, and some of them probably even identical with 

the Indian forms. Thus the placing of the Pledenstroemia zone at the top of the Lower Triassic can no 

longer stand, nor can the equivalence of the Pledenstroemia-Flemingites zone to the Olenek faunal zone of 

Siberia and the Campil faunal zone of the Mediterranean region be upheld.

2 < Waagen, W., op. cit. (Salt Range fossils, vol. 2), p. 73.

25 Mojsisovics, E. von, Arktische Triasfaunen: Acad. imp. sci. St.-P6tersbourg 

Mem., 7th ser., vol. 33, No. 0, p. 144, 1886.

2» Diener, Carl, The Trias of the Himalayas: India Oeol. Survey Mem., vol. 36, 

pt. 3, pp. 3b et seq., 1912.

Characteristic species of the Anasibirites subzone of the Meekoceras zone

lindstroemi Mojsisovics. __ _____________ _____ __.. _ _.__ ____ _

laevis Welter________________ --.._ _____ .___ _____ ___ ..___

Medlicottia noetlingi Haniel-_.-__ ___--__ _____ __ _ __ ____ _ ._

Svalbard

(?)

(?)

(?)

(?)

X 

X

India

Himalayas

X

Salt Range

X 

X 

X 

X 

X 

X

Timor

X 

X 

X 

X 

X 

X

1 X X

X

X

X

X

California 

and 

Nevada

X

X
18 LOWER TRIASSIC AMMONOIDS OF NORTH AMERICA

TIROLITES ZONE

The fauna of the classic Campil beds of the Tyrolian 

Alps and the Balkan Peninsula has been fully described by Kittl. 27 It comprises the uppermost fossil 

beds of the Lower Triassic in the standard Mediterranean sections. Its equivalents have been sought 

in other regions but found only in western America, 

in the Tirolites zone of Idaho. 28 Mojsisovics 29 thought 

that the Olenek fauna of northern Siberia should be 

correlated with the Campil horizon, and Diener 30 

was of the opinion that the Hedenstroemia beds of the 

Himalayas were the representatives of the same zone. 

But it is now rather certain that those correlations 

were not exact, the Hedenstroemia fauna being older 

and the Olenek fauna slightly younger. The Campil 

beds probably include the time equivalents of the 

Columbites zone of Albania and Idaho, but that part 

of the Tyrolian standard section appears to be barren.

The fauna of this zone appears to be definitely 

Mediterranean in origin and to have reached western 

America by migration through the Atlantic before the 

deposition of the Columbites zone of Idaho and Albania, for in Idaho it underlies the Columbites zone by 

about 30 feet and is sharply separated from that zone. 

The characteristic genus of this fauna, Tirolites, has 

been listed from the Hedenstroemia beds of India 31 

and from the Owenites beds of Timor,32 but the specimens figured from both places are by no means convincing and rather improbable. Other characteristic 

genera are Dinarites and Dalmatites.

Several species of genuine Tirolites occur in the 

Columbites zone of Albania and one in that of Idaho, 

but the faunas of these two regions are too different 

from the Campil fauna for the unlikeness to be explained by difference of facies in contemporary beds. 

Besides, the Tirolites zone of Idaho distinctly underlies the Columbites zone and is very definitely separable 

in the same continuous section.

Possibly, if the division between Lower and Middle 

Triassic must be drawn sharply at the top of the 

Campil horizon, the Albanian and the Idaho Columbites faunas must be classed as Lower Muschelkalk. 

But how are we going to correlate any outside faunas 

of this age with the Alpine equivalents, which are as 

yet unknown? The zone of Ceratites trinodosus 

is probably Lower Muschelkalk but not lowest, and 

the zone of Ceratites binodosus seems to have been 

eliminated.

27 Kittl, Ernst, Die Cephalopoden der Oberen Werfener Schichten von Muc in 

Dalmatian: K.-k. Qeol. Reichsanstalt Abh., Band 20, Heft 7, 1903.

28 Smith, J. P., The stratigraphy of the western American Trias: A. von Koenen's 

Festschrift, p. 398,1807.

26 Mojsisovics E. v'on, op. cit. (Arktische Triasfaunen), p. 142.

so Diener, Carl, op. cit. (The Trias of the Himalayas), pp. 36-42.

31 Krafft, A. von, and Diener, Carl, Lower Triassic Cephalopoda from Spiti, 

Malla Johar, and Byans: India Oeol. Survey Mem., Palaeontologia Indica, 15th 

ser., vol. 6, Mem. 1, p. 122, 1909.

«s Welter, O. A., op. cit. (Die Ammoniten der Unteren Trias von Timor), p. 149.

Characteristic species of the Tirolites zone

Tirolites cassianus Quenstedt

spinosus Mojsisovics .

quenstedti Mojsisovics - ____'_

muchianus Mojsisovics

Dalmatites attenuatus Smith _____

Tyrol

X

X

X

X

X

X

X

X

X

Albania

V

X

Idaho

X

v

X

COLUMBITES ZONE

The Columbites zone is characterized by the wide 

distribution and abundance of Columbites and Leio-? 

phyllites, by the flaring up of Celtitinae and Haloritidae of Tropitoidea, and by filiation of Meekoceratidae 

into Ceratitidae. The fauna was- first described by 

Hyatt and Smith 33 and correlated by them with the 

Olenek fauna of Siberia, a correlation that seems to 

stand the test of time. It was later described by 

Arthaber 31 from Albania and by him correlated with 

the Campil horizon of Tyrol because of the occurrence 

in it of several species of Tirolites already known in 

those beds. In Idaho the Columbites fauna occurs 

about 30 feet above the Tirolites zone, which in turn 

lies several hundred feet above the Meekoceras zone, 

the home of Meekoceras gracilitatis, M. mushbachanum, 

Flemingites aplanatus, F. cirratus, F. russelli, Hedenstroemia kossmati, and Pseudosageceras multilobatum.

The Columbites fauna of Idaho contains numerous 

species of Columbites, Celtites, Meekoceras, Xenaspis, 

and Pseudosageceras, mostly related to forms from 

Albania and somewhat distantly to those of the 

Olenek fauna of Siberia not at all to any known 

elsewhere.

The Albanian fauna contains all these elements and 

also Proptychites, Sageceras, Albanites, Procarnites, 

Isculites, Protropites, Leiophyllites and others, showing 

the richest variety of ammonoid genera known in 

the Lower Triassic and most beautifully presented in 

Arthaber's justly famous monograph.

The arguments presented in this and the following 

sections do not prove the Lower Triassic age of the 

Columbites fauna but do make it probable that the 

Columbites fauna, the Olenek fauna, and the so-called 

"Lower Muschelkalk" of the Himalayas are of the 

same age.

The Olenek fauna is known only from the vicinity of 

the mouth of the Olenek River in northern Siberia. 

It was described by Mojsisovics 35 and assigned by

33 Hyatt, Alpheus, and Smith, J. P., op. cit. (Prof. Paper 40), pp. 19 et seq. 

3t Arthaber, G. von, Die Trias von Albanien: Beitr. Palflontologie Oesterr.- 

Ungarns u. des Orients, Band 24, pp. 174-194, 1911. 

3 « Mojsisovics, E. von, op. cit. (Arktische Triasfaunen), p. 142.
LOWER TRIASSIC INTERREGIONAL CORRELATION ZONES 19

him to the Campil horizon, although the two faunas 

have nothing in common. It contains numerous 

Meekoceras, Xenodiscus, Keyserlingites, Czekanowskites, 

Olenekites, one doubtful Columbites, and a few other 

genera, mostly with species decidedly unlike those of 

the rest of the world. Only Meekoceras, Xenodiscus, 

and Columbites? suggest relationship with the Columbites fauna of Idaho.

Noetling 30 makes a very strong argument for the 

Middle Triassic age of the Olenek fauna, but it has 

not met with general assent.

This same fauna may be represented in the upper 

part of the Lower Triassic section of Svalbard, for 

Spath :J7 has listed from that island Keyserlingites, 

Olenekites, and other species closely related to if not 

identical with the Olenek species.

The Leiophyllites fauna of Timor, which apparently 

occurs at the top of the Lower Triassic of Timor 38 

represents a faunal horizon not separated stratigraphically by the explorers in that region but none the 

less distinct, containing Leiophyllites dieneri Arthaber, L. kingi Diener, L. pitamaha, Diener, Albanites 

arbanus Arthaber, Procarnites kokeni Arthaber, and 

P. skanderbegis Arthaber, all identical with species 

from the Columbites zone of Albania. Welter 39 lists 

also Tirolites meridianus and Columbites sp. from this 

fauna, but the "Columbites" is reallv Iscuhtes, a primitive member of the Haloritidae, and the so-called 

Tirolites is probably identical with " Sibirites " prahlada 

Diener. However, even without Columbites and 

Tirolites the age determination is definite and can only 

be that of the Columbites zone of Albania. This discovery carries with it another determination of farreaching importance. In the Himalayas of India the 

topmost beds of the Lower Triassic were for a long 

time supposed to lie at the Pledenstroemia horizon. 

Then the boundary was pushed upward to take in

"Noetling, Fritz. Die asintische Trias: Lethaea geognostica, Teil 2. Das Mesozoiciim, Band J, Trias, Lief. 2, p. 200, 1005.

« Spath, L. F., On ammonites from Spitsbergen: Oeol. Mag., vol. 58, pp. 297-305, 

347-350, 11)21.

>s Smith, J. P., Lower Triassic ammouoids of Timor (MS.).

"Welter, 0. A., op. cit. (Die Ammoniten der Unteren Trias von Timor), pp. 

140-150.

the Anasibirites beds of the Himalayas, the equivalent of the Upper Ceratite limestone of the Salt Range, 

which had formerly been classed by Waagen 40 as 

Middle Triassic. Now Leiophyllites kingi and L. pitamaha were described by Diener 41 from the so-called 

"Lower Muschelkalk" of India; both species occur in 

the Columbites beds of Albania and are fairly common 

at the same horizon in Timor. Krafft 42 insisted that 

the beds that carry Leiophyllites in India belonged 

to the Lower Triassic. It would now seem that he 

may have been right. At least there can be no question as to the correlation of the Columbites faunas of 

Idaho and Albania and little question as to the correctness of the correlation of these with the Olenek 

fauna of Siberia and the upper Campil beds of the 

Mediterranean. It may, however, eventually be 

necessary to place these faunas at the bottom of the 

Middle Triassic.

Among the outstanding characteristics of the 

faunal zone are the abundant occurrence of the genus 

Columbites in Idaho and Albania, the further branching out of the Gastrioceratea into Celtitidae (Celtites}, 

and Haloritidae (Isculites}, the branching out of the 

Lytoceras-Phylloceras stock (Leiophyllites}, from Xenaspis or Xenodiscus; the steady approach of the Meekoceratidae toward Ceratitidae; the increase of the socalled "Beloceratea"; and the occurrence in the Salt 

Range of India and in Albania and Idaho of very 

closely related species of the odd hungarite form 

Pseudharpoceras. Good conditions and favorable temperature must have prevailed from the Equator to the 

Arctic, otherwise the rapid development and wide 

distribution could never have taken place.

This faunal zone sees all the phyla of Triassic 

ammonites already well established and ready to 

become the parents of the wonderfully rich families 

of the Middle and Upper Triassic. The dark ages 

have passed, and the golden age of the renaissance 

is at hand.

<o Waagen, W., op. cit. (Salt Range fossils, vol. 2), p. 73.

 " Diener, Carl, Cephalopoda of the Minschelkalk: India Geol. Survey Mem., 

Palaeontologia Indica, 15th ser., Himalayan fossils, vol. 2, pt. 2, pp. 108, 109, 1895.

42 Krafft, A. von, in Hayden, H. H., Geology of Spiti: India Geol. Survey Mem., 

vol. 36, pt. 1, p. 68, 1912.'
20 LOWER TRTASSIC AMMON-OIDS OF NORTH AMERICA

Characteristic species of the Columbites zone

mirditensis Arthaber _ __

Celtites ursensis Smith _ __ _ _ _ _ -

planorbis Smith.. _____

Arnautoceltites arnauticus Arthaber _ _

Isculites originis Arthaber __ _ _____

Prosphingites ali Arthaber ... ____

Xenodiscus sulioticus Arthaber _____

jacksoni Hyatt and Smith.. _ ___ __ _____

pitamaha Diener ____ _____

kingi Diener ______ ___

Meekoceras sanctorum Smith _____

sibiricum Mojsisovics __. _ _ _ _

Proptychites latifimbriatus Waagen _ _ _ _ _ _

skanderbegis Arthaber _ _

Hedenstroemia kastriotae Arthaber _ _

Sageceras albanicum Arthaber _ _ _ _

Pseudharpoceras. ___ . ___. .-__.

Tyrol

X 

X 

X

Albania

X 

X

 x

X

X 

X 

X

X 

X 

X

X

X 

X 

X

X

X 

X 

X 

X 

X

X 

X 

X 

X

Olenek

India

Himalaya

|

X

X

X

X

X

X 

X 

X 

X

Salt 

Range

X

X

Timor

X

X 

X

X 

X

X 

X

X

Idaho

X 

X

X 

X

X

X

X

X

X

OUTLINE OF PHYLOGENY OF TRIASS1C AMMONITES

METHODS

The first step in the study of the phylogeny of 

ammonites is to assemble a series of adults in supposed 

genetic sequence and certainly in known stratigraphic 

order. This task is not so easy as it sounds, and most 

attempts of this sort have been at least partial failures. 

Waagen 43 made the first serious trial at an individual 

genetic series, although his Formenreihe was only a 

comparatively short one. Every classification in 

treatises on ammonites has been an attempt at finding 

genetic series, with what success one can easily guess 

on comparison of results.

The second step was taken by Hyatt,44 who introduced the method of breaking out young stages of 

ammonites from the mature coils. This method is 

made possible by the fact that the mature shell 

envelops and protects the young part of the coil, thus 

preserving the entire life record, in so far as it is shown 

by the shell.

43 Waagen, \V., Die Formenreihe des Ammonites subradiatus: Palaeont. Beitr. 

(Benecke & Waagen), Band 2,1869.

44 Hyatt, Alpheus, Fossil cephalopods of the Museum of Comparative Zoology; 

embryology: Harvard Coll. Mus. Comp. Zoology Bull., vol. 3, No. 5, 1872.

Of course it would be better to procure the young 

shells that had died in infancy or the larval stages, but 

they are seldom preserved, and also their recognition is 

uncertain.

Branco 45 followed the method of Hyatt but went 

much further in an attempt to formulate a general 

classification of ammonoids based on their larval 

stages. However, he did little in t'he way of comparing later larval forms with adult stages of antecedent forms, and hence his work was almost purely 

morphology and not phylogeny.

The most brilliant and satisfactory results yet 

obtained are those of Karpinsky 46 in the ontogenic 

study of late Paleozoic ammonoids. Some success was 

also attained by Wiirtenberger 47 and by Hyatt 48 in 

the investigation of Jurassic ammonites. Many other 

students have followed the lead of these pioneers with 

great success, though often with conflicting results.

« Branco, W., Beitrage zur Entwickelungsgeschichte der fossilen Cephalopoden, 

Teil 2: Palaeontographica, Band 27,1880.

46 Karpinsky, A., Ueber die Ammoueen der Artinsk-Stufe und einige mit denselben verwandten carbonischen Formen: Acad. imp. sci. St.-P6tersbourg M6m., 7th 

ser., vol. 37, No. 2, 1889.

47 Wiirtenberger, L., Studien iiber die Stammesgeschichte der Ammoniten, 1880. 

45 Hyatt, Alpheus, Genesis of the Arietidae: Smithsonian Contr. to Knowledge, 

No. 673, 1889.
OUTLINE OF PHYLOGENY OF TRIASSIC AMMONITES 21

PRINCIPLES

If assembling series of adults and development series 

of their young is difficult, correct interpretation of 

these results in terms of phylogeny is still more difficult, 

to judge from the confusion and contradictions evident 

in classifications based on them.

B'aug '10 has made an ambitious formulation of the 

relationships of Triassic to Paleozoic ammonoids, 

brilliant and stimulating but unable to stand the test 

of time and later discoveries. Frech 50 has applied 

this method to the study of Devonian, Carboniferous, 

and Triassic ammonites, reaching conclusions that are 

brilliant and daring, though not always convincing.

Arthaber 51 has summarized the results of his numerous studies of Triassic ammonoids in a systematic 

attempt at a phylogenetic classification. In this classification, however, he lias paid too little attention to 

the young stages as checks on phylogeny. Wedekind 52 has carried on Branco's formulation of the 

morphology of ammonoids, in which he has been followed by Schindewolf 53 in the genetic classification of 

Devonian genera and by Schmidt 54 in the phylogeny 

of Carboniferous forms.

Buckman and Trueman have taken the lead in 

ontogenic classification of later Mesozoic genera, and 

both seem to have attained results of permanent value.

Mojsisovics carried, on for more than 40 years his 

epochal studies of Triassic ammonites, always attempting a genetic classification, but the ontogenic check 

was lacking, and his taxonomy was largely empirical, 

though it has usually proved to be right. Waagen 

has followed the same principle in his ponderous works 

on Indian faunas, without the same degree of success.

For the past third of a century Carl Diener has been 

publishing a stately series of monographs dealing with 

the classification and biostratigraphy of Triassic ammonites. In. these monographs he has used the ontogenic check where it was possible to do so, and consequently his results have won more general acceptance 

that those of any other writer on this subject.

A study of the works of the writers cited above 

shows that most of them are in agreement in most 

respects, which is more than could be expected if there 

were not some basic reason, and that reason is simply 

that they are at least approximately correct in their

<o Hung, 13., Los ammonites du Permien et du Trias: Soc. gcol. France Bull., 3d 

sor., vol. 22, pp. 385-412, ISM; Etudes sur les goniatites: Soc. geol. France Mem., 

PfUoontologie, Mem. 18, 1808.

80 Froch, Fritz, Ueber clevonische Ammoneen: Beitr. Pnldontologie Oesterr.- 

Ungarns u. (Ics Orients, Band 14, 1900; Die Dyas: Lethaea geognostica, Teil 1, Das 

Piihieozoiciim, Bnnd 2, Lief. 3, 1001.

81 Arthaber, 0. von, Die Trias von Albnnien: Beitr. PalSoutologie Oesterr.- 

Ungarns u. des Orients, Band 2-1, 1011.

42 Wodokind, \l., Die Genera der Palaeoanimonoidea (Goniatiten): Palaeontographicn, .Band (>2, pp. 83-184, 1017.

83 Schindowolf, 0. H., Beitrfige zur Kenntniss des Pala'ozoicums in Oberfranken, 

OsUliilringon und dcm stlchsischcn Vogtlande: Neues Jahrb., Beilage-Band 40, 

pp. 303-500, 1023.

«« Schniidt, 11., Die carbonischen Goniatiten Deutschlands: Preuss. geol. LandesunsUilt, Jahrb., Band 45, pp. 480-009, 1925.

conclusions. Their agreement depends on this principle that resemblance between forms of Cephalopoda 

usually means relationship. And this leads to serial 

resemblance and orderly modification in proper 

sequence.

The mistakes in classification and frequent lack of 

agreement come mainly from lack of material and from 

erroneous inferences as to what changes may have 

taken place during the gaps in the record. These gaps, 

though still a hindrance, are becoming less yearly. 

The most notable gaps at present are the lack of Tropitidae in horizons 1, 2, 3, and 4 of the Lower Triassic; 

Arcestidae, Haloritidae, Ptychitidae, and Haueritidae 

in the upper Permian; Sageceratidae in the "Coal 

Measures''? (Pennsylvanian), Permian, and horizons 

1 and 2 of the Lower Triassic; and Xenodiscidae in the 

upper Mississippian and "Coal Measures" (Pennsylvanian). These gaps in the record show that there is 

much collecting still to be done in the upper Permian 

and Lower Triassic in the known regions; also that 

many missing records may be concealed in regions as 

yet unknown.

LIMITATIONS OF FIELD CONSIDERED

The ammonoid phylogeny here under consideration 

is limited to late Paleozoic and early Mesozoic faunas. 

The study of Devonian genera is still a source of conflict, with little agreement among the attackers of the 

problems, and is involved in a whirlpool of nomenclature.

Late Paleozoic and early Mesozoic genera repeat, in 

their ontogeny, their ancestral history with a fair degree of exactness, for they had not been greatly affected 

by unequal acceleration of development and scarcely 

at all by retardation or arrest of development. Their 

ontogeny is beautifully simple and direct, and in them 

it is easy to find genetic series of adult genera with 

which to compare the ontogenic series of stages in any 

species. Such simple development and positive recapitulation have been shown by the writer to exist in 

Glyphioceras, Marathonites, Uddenites, Parcvpronorites, 

Daraelites, and Paralecanites of the Carboniferous and 

in A.spenites, Pseudosageceras, Cordillerites, Columbites, 

Tropigastrites, Tropites, Ussuria, Meekoceras, Xenodiscus, and many others in the Triassic. Karpinsky 

has also traced the Pronorites-Medlicottia stock from 

the Carboniferous into the Mesozoic with complete 

recapitulation.

In later Mesozoic (Jurassic and Cretaceous) genera 

recapitulation of phylogeny in ontogeny is not so 

distinct, because all the disturbing factors unequal 

acceleration or telescoping of characters, retardation, 

and developing of cenogenetic characters have combined to obscure the record. Cretaceous and Jurassic 

ammonoids still have a goniatite stage at the beginning 

of their larval development, but it is no longer possible
22 LOWER TRIASSIC AMMONOIDS OF NORTH AMERICA

to point out with certainty the particular ancestral 

goniatite genus. In sharp contrast with the uncertain 

and garbled recapitulation of ancient history is the 

positive testimony as to their immediate ancestry. 

The Phylloceratidse and their kin are the only Jurassic 

and Cretaceous stock of which we know the ancient 

genealogy.

RECAPITULATION WITH EXAMPLES

As the result of more than half a century of intensive 

study of the ammonoids paleontologists have found 

that probably all ammonites and ceratites show, in 

their youth, goniatite stages. These stages are not 

all the same but very different, and at least some of 

them resemble in all essentials certain Paleozoic 

goniatite genera, which Hyatt called "radicles." In 

general the ammonites with similar young stages are 

sufficiently alike to be classed together. Very seldom 

does classification based on ontogeny contradict that 

based on external form and characters. The agreement is so evident to the worker in this group that he 

wonders at the doubt or negation of some naturalists, 

who affirm that recapitulation of phylogeny in 

ontogeny is an illogical fallacy.

The dissenting or doubting naturalists tell us that 

it would be very remarkable if young stages of later 

forms should resemble in any logical and consistent 

way the adult stages of their ancestors that it is too 

fanciful to be true, and that recapitulation is a myth. 

How much more remarkable and improbable it would 

be if the young stages of a large group of manifestly 

related genera all resembled a certain antecedent genus 

purely by accidental adaptation; and if such surprising 

resemblances were uniformly shown, which is actually 

the fact, chance can not be conceived to have hit 

regularly and consistently upon them by adaptation 

alone. Heredity is the only possible explanation of 

the evidence.

All ammonites are supposed to show goniatitelike 

larval stages. All do, so far as they have been observed, and this statement applies to most of the 

known genera. All ammonites, however, do not show 

merely a generalized goniatitelike larval stage, but 

each group has its own particular sort of larval stage, 

and each of these stages is like a definite and not 

generalized Paleozoic goniatite genus or group of 

genera. This phenomenon is too constant and regular 

to be accidental. (See pis. 58, 59, and 60.)

Blind chance could hardly be conceived to have hit 

consistently upon the peculiar Pronorites stage of 

Medlicottia, Uddenites, and Cordillerites. (See pi. 60, 

fig. 14.) It would require some credulity to believe 

that the young of the Ceratitoidea all imitate, by 

mere chance, the definite group of Prolecanites and 

later that of the Xenodiscidae. (See pi. 59, figs. 8-35.) 

It would be hard to see how the Haueritidae by mere

accident could duplicate, in their young stages, 

Aphyllites (pi. 60, figs. 10-13), and the Sageceratidae 

could hardly be imagined to duplicate by fortuitous 

and unmeaning variation the very characteristic 

Devonian genera Beloceras and Timanites (pi. 60, 

figs. 1-6 and 32). It would be surprising if the 

Tropitoidea, by mere chance, consistently imitated, 

in the gastrioceran young of Celtites, Columbites, 

Tropigastrites, and Tropites, the definite and salient 

characters of Paragastrioceras. (See pi. 58, figs. 1-44.) 

It would be unbelievable that the Arcestoidea alone 

' would accidentally duplicate in their youth, regularly 

and consistently, Adrianites and Marathonites. (See 

pi. 59, figs. 1-6.)

If all these young shells were merely generalized 

forms, these resemblances might be thought to be 

accidental; but they are all intensely specialized 

groups, very definite and with salient characters, even 

in the small larval stages. The development history 

of the organisms themselves is the final court of appeal 

and has greater authority than ex cathedra statements 

from any source whatsoever.

All the Gastrioceratea, so far as known, have a distinct gastrioceran larval stage, as is especially well 

shown in the young of Columbites spencei, Tropigastrites halli, and T. trojanus, which duplicate in their 

youth the typical group of Gastrioceras listeri. This 

same radicle is indicated in the young of the group of 

Tropites subbullatus, Paratropites sellai, Discotropites 

sandlingensis, and D. mojsvarensis but of a much smaller 

size. (See pi. 58, figs. 1-41.) The group of Gastrioceras globulosum is duplicated in the young of the 

Haloritidae, Acrochordiceras, Sagenites, and Juvavites. (See pi. 58, figs. 36-44.)

The earlier Arcestoidea, such as Marathonites of the 

Cyclolobidae, show a gastrioceran stage in earty youth 

that rapidly goes over into stages that resemble Adrianites. The later Arcestoidea, such as Arcestes of the 

Arcestidae, omit or slur over the gastrioceran stage 

but have a very definite Adrianites stage and later 

recapitulation of Marathonites. (See pi. 59, figs. 1-7.)

Most Permian and Triassic Gephyroceratea have 

obscured or lost the Gephyroceras stage, but it is retained distinctly in Dalmatites of the Hungaritidae and 

in Hedenstroemia of the Meekoceratidae; also in the 

Timanites stage of Aspenites. (See pi. 60, figs. 4-6, 

and 24-26.)

Among the Prolecanitoidea the Xenodiscidae, which 

include Paralecanites, Lecanites, Xenodiscus, Ophiceras, 

and Flemingites, recapitulate clearly Prolecanites and 

later Lecanites. Some of the Meekoceratidae, as 

Meekoceras mushbachanum, are known to recapitulate 

Prolecanites, but most of them apparently have lost or 

obscured that stage. (See pi. 59.) The more specialized Ceratitoidea, Ceratites and its subgenera or allied 

genera, have lost the Prolecanites stage but so far as
OUTLINE OF PHYLOGENY OF TRIASSIC AMMONITES 23

known retain that of Lecanites, followed closely by one 

that corresponds to Xenodiscus of the subgeneric group 

Genodiscus. The latter stage is seen distinctly in the 

young of Anasibirites, Ceratites, Paraceratites, Hollandites, Philippites, Beyrichites, Gymnotoceras, Anolcites, Nevadites, and Protrachyceras. (See pi. 59.) 

The Prolecanites stage reappears by palingenesis in the 

late Triassic retarded or reversionary genera Clionites 

and Polycyclus. (See pi. 59, figs. 33-35.) The 

Pro.noritoid.ea recapitulate a faii-ty definite Prolecanites stage in Daraelites, Pronorites, Uddenites, and 

Medlicottia, and all these repeat the particular radicle 

Pronorites, as does also Cordillerites. (See pi. 60.)

Of the Beloceratoidea Aspenites, Pseudosageceras, 

and Sageceras recapitulate Beloceras or some kindred 

form with fair distinctness. (See pi. 60.)

Among the Dimorphoceratoidea Tfialassoceras repeats Dimorphoceras, and Ussuria recapitulates both 

Dimorphoceras and Thalassoceras. (See pi. 60.) Lanceolites recapitulates Aphyllites, and Fremontites repeats 

both Aphyllites and Lanceolites. (See pi. 60.)

The young stages referred to above are figured on 

Plates 58, 59, and 60, and elsewhere in the present 

work, under the descriptions of species and genera.

RADICLES

The radicles here considered are relatively simple 

Paleozoic goniatite genera, supposed to be ancestors 

of later and more complex groups. These primitive 

ancestral forms are recapitulated with more or less 

distinctness in the larval and adolescent stages of 

later genera, each major group having its own particular type of young stage.

Thus Plates 43, 44, and 45 are in a sense a gallery 

of ancestral portraits, in which the essential characters 

of the young stages of later generations may be discerned. But this statement is not meant to be taken 

too literally. It is not known, nor even thought, 

that the species chosen here for illustration are the 

actual ancestors, but merely that they are typical 

representatives of the groups that are believed to be 

ancestral. For it is highly probable that all genera 

were more or less polyphyletic and that they did not 

originate from a single pair or even from a single species 

but from several species varying more or less in a general 

direction.

The genus Gephyroceras, represented by G. regale 

(pi. 44, figs. 6-8) from the Upper Devonian, is typical 

of the Devonian and is recapitulated in the young of 

Xen.od.isc.id.ae, Meekoceratidae, and Ceratitidae. It is 

not implied that this particular species, or even this 

particular genus, is the ancestor of the Gephyroceratea. 

It is merely one out of many that possess characteristics in common, indicating at least consulship.

The genus Prolecanites is represented by P. applanatus Frech (pi. 44, fig. 1), which is the finest species of 

a world-wide lower Carboniferous group. This genus 

has been badly split up, unnecessarily renamed, and 

finally left out entirely in the 1924 edition of K. A. 

von Zittel's "Grundziige der Palaontologie." But of 

course a group that was properly named and defined 

and that played an important part in cephalopod 

history can not be ignored and cast into oblivion. 

There are many species of it in the lower Carboniferous 

of Europe and America, good horizon markers and 

undoubtedly good breeders, for their characters reappear unmistakably in the young of the Xenodiscidae and 

Meekoceratidae in the Lower Triassic. Heredity will 

out.

The genus Gonioloboceras, represented by G. welleri 

Smith (pi. 43, figs. 1-3), is characteristic of the Carboniferous of North America and has perhaps less 

right in the family gallery than most of the others. 

It is a doubtful link in the line between the Gephyroceratidae and Dimorphoceratidae, a possible ancestor 

of Neodimorphoceras and of the Haueritidae, though a 

rather improbable one.

The genus Neodimorphoceras (pi. 43, figs. 4-7) was 

named by the writer 55 "Texites," but while his paper 

was in press he was anticipated by Schmidt,56 who 

renamed the type species Neodimorphoceras. This 

genus is almost the only known link in the "Coal 

Measures" of North America between the Gephyroceratidae of the Devonian and the Thalassoceratidae of 

the Permian and Lower Triassic. It is also the only 

known genus of the "Coal Measures" that points toward the Haueritidae. However, the writer believes 

that Neodimorphoceras is not in the direct ancestral 

line of either Thalassoceratidae or Haueritidae but 

rather that it is what genealogists call a "collateral 

ancestor." Dimorphoceras comes nearer to filling the 

requirements of the ancestor of Thalassoceratidae.

For the sake of completeness the family gallery 

should contain a portrait of Aganides (Brancoceras, 

Imitoceras), which, according to Schmidt,57 is the radicle 

of all Carboniferous goniatite genera. That assumption, however, is so patently impossible that no discussion is necessary. Aganides may be the ancestor of 

Gonioloboceras, and thus possibly of the Thalassoceratidae, but further its claims can hardly go.

The genus Aphyllites, represented by A. marcellensis 

(pi. 45, figs. 1-3), is diagnostic of the Devonian and 

ranges to the very base of the Carboniferous under the 

name Agoniatites. There are no upper Carboniferous

55 Smith, J. P., Upper Triassic marine invertebrate faunas of North America: 

U. S. Oeol. Survey Prof. Paper 141, p. 73, 1927.

so Schmidt, H., Die carbonischen Goniatiten Deutschlands: Preuss. geol. Landesanstalt Jahrb., Band 45, p. 600, 1925.

« Idem, p. 531.
24 LOWER TRIASSIC AMMONO1DS OF NORTH AMERICA

(Pennsylvanian and Permian) representatives of it, and 

yet it is duplicated unmistakably in the young of 

Lanceolites of the Lower Triassic and of Fremontites of 

the Upper Triassic. Some genus as yet unknown or 

unpublished must have continued the line through the 

"Coal Measures'' and Permian, and that genus could 

not have been Neodimorphoceras, though it must have 

been something like it, only without the rudimentary 

adventitious lobes and with a very large lateral, weakly 

serrated.

The genus Beloceras, represented by B. multilobatum 

(pi. 44, fig. 5), is characteristic of the Devonian. It is 

recapitulated distinctly in the young of Pseudosageceras and Sageceras and less definitely in the young of 

Aspenites of the Triassic.

The genus Timanites, represented by T. acutus (pi. 

44, figs. 2-4), is typical of the Devonian and is supposed 

to be a connecting link between Gephyroceras and 

Beloceras. It is recapitulated only in the young of 

Aspenites of the Lower Triassic.

The genus Prodromites, represented by P. gorbyi 

(pi. 44, fig. 21), is known only in the lowest beds of the 

lower Carboniferous (Mississippian) of North America. 

This genus, which is the only certainly known member 

of the Beloceratea in the Carboniferous, can not be in 

the direct line, for it is more specialized than its Lower 

Triassic kinsmen, but it is introduced here to show the 

continuity of the stock.

The genus Acrocanites (pi. 44, fig. 9), known in the 

lower Carboniferous of Germany in a single fragmentary specimen, has been described as a member of the 

Prolecanitidae with beloceran shape and septa. When 

better known it will probably give a good connecting 

link between Beloceras and the Sageceratidae, for it is 

rather definitely recapitulated in their young. At 

present there is no known genus in the entire Carboniferous that fills these requirements.

The genus Pronorites (pi. 45, figs. 4-5), represented 

by P. timorensis of the lower Permian, a genus of established respectability, is fairly common from the top of 

the lower Carboniferous to the middle of the Permian 

and is recapitulated very definitely in the young of 

Parapronorites, Medlicottia, and Uddenites (pi. 45, figs. 

12-13), less so in that of Cordillerites, and still less so in 

the young of Daraelites. The young of other members 

of the Pronoritidae have not been examined, for lack 

of suitable material.

The genus Gastrioceras is represented by G. listen (pi. 

43, figs. 8-13), the type of the genus, and by G. welleri 

(pi. 43, figs. 14-17), a typical member of the group of 

G. globulosum. .The group of G. listeri is directly ancestral to the Permian Paragastrioceras (pi. 45, figs. 

6-8), and through it to the grandparents of Celtites, 

Columbites; Tropigastrites, and Tropites. It is recapitulated very definitely in the young of all these genera. 

The group of G. globulosum includes the forebears of the 

true Ptychitidae, the Arcestidae, the Haloritidae, and

probably of the Cladiscitidae. The genetic series 

Juvenites »Thermalites ^/sc^toes ^Haloritidae is fairly 

well established, with good recapitulation all along the 

line. The Ptychitidae appear to have branched off 

from this stock in Paranannites of the Lower Triassic 

and so far as their young have been observed give at 

least partial recapitulation.

The subgenus Paragastrioceras was named by 

Tchernow 58 to include the rather slender evolute forms 

of the Permian, such as Gastrioceras zitteli (pi. 45, 

figs. 6-8), which is here chosen to represent the group 

and to serve as type, as Tchernow appears not to 

have designated a type. It has been unnecessarily 

renamed by Wedekind 59 l< Girtyites," but there is no 

uncertainty as to what Tchernow meant by Paragastrioceras, hence that name is coming into general 

use. Its first" appearance is in Gastrioceras branneri, 

in the lowest beds of the Pennsylvanian of North 

America. It is abundant and characteristic in the 

Permian of the Urals, Sicily, and Texas and grades 

over into Celtites and Columbites of the Lower Triassic, 

giving a perfect transition to the Tropitidae.

The genus Agathiceras, which is represented by 

A. ciscoense (pi. 43, figs. 22-24) of the Pennsylvanian, 

is characteristic of the "Coal Measures" and lower 

Permian. It is derived from Gastrioceras and is the 

probable ancestor of the Cladiscitidae. The genus 

has been regarded by Arthaber 61 as the radicle of the 

Arcestoidea, but that is due to a confusion of names 

and blending of this with Adrianites, the next genus 

to be treated.

The genus Adrianites, which is represented by 

A. timorensis (pi. 45, figs. 9-11) of the middle Permian, 

is derived from Gastrioceras, possibly through Paralegoceras and Schistoceras, and is ancestral to the 

Arcestidae, probably through Marathonites of the 

"Coal Measures" and Permian. Marathonites so far 

as known antedates Adrianites in its appearance on 

the scene, but this is probably only apparent, for the 

young of Marathonites and of all other Arcestidae that 

have been studied recapitulate Adrianites in no uncertain terms.

The genus Marathonites is represented by M. ganti 

(pi. 43, figs. 18-20) of the upper Pennsylvanian of 

America. This group was first included in Popanoceras 

and later in Stacheoceras but was finally segregated 

by Bose 62 to include the rather primitive members in 

the "Coal Measures" and Permian. As thus defined 

and restricted, it is a well-marked unit, recapitulated

5S Tchernow, A., L'etage d'Artinsk: Soc. imp. nat. Moscou Bull., new ser., vol. 

20, p. 392, 1907.

s' Wedekind, K., Die Genera der Palaeoammonoidea: Palaeontographica, Band 

62, p. 160, 1917.

oo Smith, J. P., The Carboniferous ammonoids of America: U. S. Oeol. Survey 

Mon. 42, p. 83, pi. 40, flgs. 8-13, 1903.

« Arthaber, G. von, Die Trias von Albanien: Beitr. Paliiontologie Oesterr.- 

Ungarns u. des Orients, Band 24, p. 178, 1911.

62 Bose, Emil, The Permo-Carboniferous ammonoids of the Glass Mountains, 

west Texas: Texas Univ. Bull. 1762, p. 133, 1917.
OUTLINE OF PHYLOGENY OF TRIASSIC AMMONITES 25

in the young of more complex and later Arcestoidea. 

According to the definition, it is not a primary radicle, 

being a primitive ammonite, but it is very abundant 

in the lower Permian of Sicily, the Urals, Texas, and 

Timor and deserves recognition as a secondary 

radicle a new starting point for a vigorous and prolific stock of world-wide significance.

The statements concerning the ontogeny of the 

ammonoids made here and elsewhere in this paper 

are not mere assertions but are based on observations 

made by the writer and published in the following 

work's by him:

Permian ammonoids of Timor; 2e Nederlandsche TimorExpeditie onder Leiding van Dr. H. G. Jonkert: Jaarboek van 

het Mijnwezen in Ned. Indie, 1926, Verb. 1, 1927.

Lower Triassic ammonoids of Timor (MS.).

The Triassic cephalopod genera of North America: U. S. 

Geol. Survey Prof. Paper 40, 1905.

The Carboniferous ammonoids of America: U. S. Geol. 

Survey Mon. 42, 1903.

The Middle Triassic marine invertebrate faunas of North 

America: U. S. Geol. Survey Prof. Paper 83, 1914.

Upper Triassic marine invertebrate faunas of North America: 

U. S. Geol. Survey Prof. Paper 141, 1927.

The transitional Permian ammonoid fauna of Texas:5 Am. 

Jour. Sci., 5th ser., vol. 17, pp. 63-80, 1929.

Phylogeny of Lower Triassic ammonites

Devonian

Phenacoceras." 

Gephyroceras."

Prolecanitoidea.

Pronoritoidea.

Aphyllites." 

Dimorphoceratoidea.

% $ Beloceras. 6

OT3

o -3 U+a .limanites."

PQ

Mississippian and Pennsylvanian

Prolecanites. 0 

Xenodiscidae.

Hungaritidae.

Pronorites. 6 

Pronoritidae.

D i m o rp h o ceras . 6 

Neodimorphoceras. b

Prodromites." 

?Acrocanites. 6

Permian

Lecanites. 6 

Paralecanites. 6 

Paraceltites. b

Xenodiscus. c 

Xenaspis. 0

Meekoceratidae.

Hungarites." 

Otoceras. c 

Dalmatites. 6

Pronorites. 6 

Medlicottia. d 

Parapronorites." 

Uddenites. 0 . 

Sicanites. c 

Daraelites. 0 

Sundaites."

Thalassoceras. c 

Thalassoceratidae.

Haueritidae.

Sageceratidae.

Lower Triassic

Lecanites. b 

Paralecanites. 6

Xenodiscus. c

Xenaspis. c 

Genodiscus. 6 

Parati rolites'. 0 

Ophiceras." 

Flemingites. 0

Meekoceras. 0 

Clypeoceras. 0 

Prionites. c 

Dagnoceras. c 

Leiophyllites. 0 

Anasibirites. c 

Kashmirites."

Inj'oites. 6 

Hungarites. 0 

Otoceras. 0 

Dalmatites. c

Episageceras.'' 

Albanites." 

Cordillerites."

Ussuria. d 

Procarnites.'' 

?Sturia. d

Lanceolites. d

Sageceras. c 

Pseudosageceras. c 

Aspenites. 6

CU 

O)

o

Simple gonintito stage. b Lobes beginning to subdivide. Lobes serrated. d Ammonitic stage.
26 LOWER TRIASSIC AMMONOIDS OF NORTH AMERICA

Phylogeny of Lower Triassic ammonites Continued

Gastrioceratea

Devonian

Cyclolobidae.

Mississippian and Pennsylvanian

Gastrioceras ° 

Glyphioceras. 0 

Homoceras. 0

Haloritidae.

Agathiceras. 6

Schistoceras. 6 

Paralegoceras. 6

Shumardites. 6 

Marathonites. 0

Permian

Paragastrioceras. " 

Tropitidae.

Timorites. c 

Hoffmannia. 6

Ptychitidae. 

Agathiceras. b 

Arcestidae. 6 

Adrianites. 6 

Schistoceras. 6 

Paralegoceras. b

Shumardites. 6 

Marathonites. c 

Perrinites. d 

Waagenoceras. d 

Cyclolobus. d 

Hyattoceras. rf

Lower Triassic

Celtites." 

Columbites. 0 

Protropites."

Therm alites. c 

Stephanites. 0 

Isculites. d 

Acrochordiceras. d

Juvenites. 6 

Paranannites." 

Prosphingites. 0

Parapopanoceras. d

' Simple goniatite stage. 6 Lobes beginning to subdivide. <= Lobes serrated. 

Synopsis of phylogeny of Lower Triassic ammonites

Gephy roceratea.

Prolecanites °_________.__Ceratitoidea.

1 >Hungaritidae. 

Pronorites ° ____________Medlicottiidae.

1 >Noritidae. 

Dimorphbceras °_ _____ _ _Thalassoceratidae.

?____________,_________ Haueritidae.

Beloceras a____________Sageceratidae.

f r

. _ _ _ Gymnitidae. 

 >Phylloceratidae.

d Ammonitic stage.

 >Pinacoceratidae.

»Cladiscitidae.

Gastrioceratea _______________ Gastrioceras

Arcestoidea.

1 Trooitoidea /Tropitidae. J.ropitoiaea-_-_.________| Haloritidae

[ Ptychitidae.

0 Primary or goniatite radicles.

Timaniles is the first ammonoid to develop true auxiliary 

lobes; Beloceras is the first to develop adventitious lobes; Dimorphoceras is the first to subdivide the primary lobes; Prodromites is the first to develop serrations on the lobes; Perrinites 

is the first to develop ammonitic lobes. .

The most retarded forms in sepfcal development are 

the most advanced in sculpture for example, Gastrioceras and the Tropitidae.

The most accelerated in septal development are the 

most retarded in sculpture for example, the Cyclobidae, and Arcestidae. Contrast also the Meekoceratidae and Ceratitidae (retarded in septation and 

accelerated in sculpture) wi'th the Medlicottiidae, 

Thalassoceratidae, and Sageceratidae (accelerated in 

septation and retarded in sculpture). The explanation of this phenomenon is probably that as the 

simply septate forms grew larger they needed additional protection against fracture of the shell. This 

protection could be had in two ways by complication 

of the septa or by roughening the sculpture. They did 

not need both, and accordingly some groups became 

trachyostracan (rough-shelled), with simpler septa, 

whereas others became leiostracan (smooth-shelled), 

with more complicated septa. This could and did 

happen within the same phylum, and consequently it

can not be used in the segregation of major groups. 

The old classification of Leiostraca and Trachyostraca 

has been definitely abandoned.

Persistent goniatite stages in the Permian

Gastrioceratea:

Hoffmannia Gemmellaro.

Adrianites Gemmellaro.

Agathiceras Gemmellaro.

Paralegoceras Hyatt.

Schistoceras Hyatt.

Gastrioceras Hyatt.

Paragastrioceras Tchernow. 

Gephyroceratea:

Pronorites Mojsisovics.

Paraceltites Gemmellaro.

Paralecanites Diener.

?Nomismoceras Hyatt.

Lecanites Mojsisovics.

Persistent goniatite stages in the Lower Triassic

Gastrioceratea:

Nannites Mojsisovics. 

Juvenites Smith. 

Arnautoceltites Diener. 

Celtites Mojsisovics. 

Styrites Mojsisovics.
OUTLINE OF PHYLOGENY OF TRIASSIC AMMONITES 27

Gephyroceratea: 

Lecanites Mojsisovics. 

Paralecanites Diener. 

? A in bites Waagen. 

?Kymatites Waagen. 

Hololobus Kittl. 

Beatites Arthaber. 

Proavites Arthaber.

Recapitulation of goniatite stages in the Permian

Medlicottia. _________________________

Uddenites. ---------------------------

Marathonites. . -----------------------

Paralegoceras. ----- -------------------

Schistoceras --------------------------

Shumardites- . .._____--____-______--_-

Prolecnnites

X 

X

Prouorites

X 

X 

X 

X 

X?

Dimorphoceras

X

Gastrioceras

X 

X 

X 

X

Paracelliles

X 

X

Uddenites

X 

X 

X

Thalassoceras

X

Paralegoceras

X? 

X 

X 

X?

Paralecaniles

Propinacoceras

X 

X

Shumardiles

X

X

Recapitulation of goniatite stages in (he Triassic

Gastrioceras

spencei--_-____--__---_---- X

Tropigastrites. . ---------------- X

Tropites _._____-___----__---_-. X

Paratropites sellai. ___-_____--- X

Gaslrioceras

Thermal ites tliermarum _______.. X

Metasibirites--------------- _ X

Juvavites. -. . _._______-_-__.___ X

Lccontoiceras californicum.______ X

Celtites

X 

X 

X 

X 

X 

X? 

X? 

X?

Juveniles

X 

X 

X 

X 

X 

X

ColumbitesTropigaslriles

X 

X 

X 

X? 

X? 

X?

Thermaliles

.X

X 

X 

X

......

X 

X 

X 

X

Recapitulation of goniatite stages in the Triassic Continued

"Pi i*fi i"_-~.r^£i n -*.PPT*1 Q

Ophiceras dienerL _

pitamaha____ _ _ _ _ _

Hedenstroemia kossmati... _.- .

Meekoceras gracilitatis---___-

mushbachanum ____ . _..

Clypeoceras--___---____ .___-_

Anasibirites -.__ _____-- . _

Goniodiscus beyrichi. -----------

Hollandites organL _____________

G ymnotoceras blakei .-__--______

Aspenites acutus ________--__-__

Pseudosageceras multilobatum. _ _

Sageceras gabbi__ -____-__-__ _

Ussuria waageni. _____'_ _______

Lanceolites compactus ___ _____

bicarinatus. __--_------_

Fremontites ashleyi -._--__

Cordillerites angulatus. __--___-_

Gastrioceras

X 

X

Oaslrioceras

X 

X

Oephyroceras

X 

X

X

X 

X 

X 

X 

X

X 

X

X 

X 

X

Gephyroceras

X

Aphylliles

X 

X 

X

Pronoriles

X

Nanri iles

X 

X

Adrianites

X 

X

Prolecanites

X 

X 

X 

X

X 

X 

X

X

X 

X 

X 

X 

X 

X

X 

X

Timaniles

X

Dimorphoceras

X 

X? 

X? 

X?

Uddeniles

(?)

Paranaunites

X 

 X

Prosphingiles

(?) 

(?)

Paralecanites

X 

X 

X 

X 

X 

X 

X 

X 

X 

X 

X

X 

X 

X

X 

X 

X 

X 

X 

X 

X 

X 

X 

X 

X 

X 

X

Beloceras

X 

X 

X

Thalassoceras

X

67664 32 3
28 LOWER TRIASSIC AMMONOIDS OF NORTH AMERICA

Geographic distribution of Lower Triassic genera of ammonites

Xenodiscidae

T.OPO ni'fpc; TVTm dictnvipc!

Phylloceratidae

Meekoceratidae

Prionites Waagen.. _____ _ _ _

T^o or n n f» P V n G A vHi *~i l~iAT*

Ceratitidae

Olenekites Hyatt. _ __ __ __

Kevserlingites Hyatt___ ' __ - -

Durgaites Diener _ _ _ _ _

Hungaritidae

Sageceratidae

Asperates Hyatt and Smith. __._.. _

Thalassoceratidae

Ussuria Diener. __ _ _

Haueritidae

Pronoritidae

?Adrianites Arthaber.. __._ _ _ ____

Tyrol

(?)

X

X

X

X

X

X

X

X

X

X

Albania

X

X

v

X

X

v

v

X

X

X

v

X

X

v

v

v

X

v

v

X

Arctic 

region

X 

X

X

X

X

X

X

X

X

X

(?)

X

X

\/

X

v

India

X

X

X

X

X

X

X

X

X

(?)

X

X

X

X

X

X

X

X

X

X

(?) (?) (?)

(?)

X

X

X

(?)

v

X

X

X

X

X?

X

v

Timor

X

X

X

X

X

X

X

(?)

X

X

X

(?)

X

v

X

X

(?)

(?)

X

(?)

X

X

X

X

X

(?).

X

X

Western 

America

X

X

X

(?)

X

X

X

(?)

X

X

X

X

X\s

X\s

X

(?) (?)

X

X

X

X

X

X

X

X

X

X
PHYLOGENETIC CLASSIFICATION

Geographic distribution of Lower Triassic genera of ammonites Continued

29

Tropitidae

Haloritidae

Arcestidae

Ptychitidae

Owenites Hyatt and Smith_ _ _____ _______ __-__ _-___ ------

Tyrol Albania

(?)

X

X

X

(?)

X

X

X

X

X

X

(?)

X

X

Arctic 

region

(?)

X

X

v

India

X?

X

X

X

X

X

X

X

X

X

Timor

X

X

X

X

X

X

Western 

America

X

X

X

X

X

X?

X

X

X

X

X

X

X

PHYLOGENETIC CLASSIFICATION

GEPHYROCERATEA

As here defined, the Gephyroceratea include the 

Gephyroceratea as named by Arthaber 63 and also his 

Beloceratea and the Gymnitinae out of his superfamily Tornoceratea. It is thus a clan, of less extent 

than a suborder and greater than a superfamily. This 

clan includes as super-families the Prolecanitoidea, 

Beloceratoidea, Dimorphoceratoidea, and Pronoritoidea.

All the genera and families that compose this clan 

are supposed to be descendants of the primary radicle 

Ge/phyroceras and have a short body chamber, laterally 

compressed whorls, and little sculpture. They range 

in septation from simple goniatitic lobes (Gephyroceras, 

Timanites} through multiplicate types (Beloceras} to 

highly specialized ammonitic septa (Ussuria, Haueritidae, Trachyceratea).

The group is roughly synonymous with "Prole"- 

cani tide's" of Hang, 64 excluding Agathiceratidae, 

Cyclolobidae, and Arcestidae (Gastrioceratea) and 

including Thalassoceratidae and Ceratitidae, which 

Hang placed under Glyphioceratidae.

Superfamily PROLECANITOIDEA

The name Prolecanitoidea is substituted for the 

older designation Prolecanitidae, which has been used

»3 Arthaber, 0. von, Die Trias von Albanian: Beitr. Palaontologie Oesterr.- 

Ungnrns u. des Orients, Band 2-t, p. 177, 1911.

0< Haug, E., Les ammonites clu Permien et du Trias: Soc. g6ol. France Bull., 3d 

scr., vol. 22, p. 380. 1894.

for too many different things for the family, for the 

superfamily, and even for a suborder. Also, the new 

term is in harmony with the long accepted usage of 

Tropitoidea and Arcestoidea for the respective superfamilies of equal rank with Prolecanitoidea. The 

superfamily Prolecanitoidea is nearly synonymous 

with Ceratitoidea but omits the Hungaritidae and 

includes the Gymnitidae, Phylloceratidae, and Xenodiscidae, as well as the ancestral family Prolecanitidae. 

It is nearly synonymous with the " Prole" canitideV' 

of Haug 65 but excludes the Arcestoidea and includes 

the Ceratitidae, which Haug placed under the superfamily Glyphioceratidae. Prolecanitoidea is not 

synonymous with the Prolecanitidae of Karpinsky, 68 

who included in it also the Pronoritidae and Medlicottiidae. As restricted, the superfamily includes the 

Prolecanitidae, Xenodiscidae, Meekoceratidae, Gymnitidae, Phylloceratidae, Ceratitidae, and Trachyceratidae.

Family XENODISCIDAE

The phylogeny of the Xenodiscidae is of special 

significance, as it deals with forms transitional from 

simple Paleozoic goniatites to Triassic near-ammonites. This family is the ancestral group of the 

Ceratitoidea, a suborder which embraces a large 

majority of Triassic ammonites.

05 Idem, p. 386.

00 Karpinsky, A., Ueber die Ammoneen der Artinsk-Stufe und einige mit denselben verwandton carbouischen Formen: Acad. imp. sci. St.-P6tersbourg M6m., 

7th ser., vol. 37, No. 2, p. 4, 1889.
30 LOWER TRIASSIC AMMONOIDS OF NORTH AMERICA

The Ceratitoidea include the following families:

Xenodiscidae + Phylloceratidae + Gymnitidae. 

Meekoceratidae. 

Ceratitidae+Trachyceratea. 

Hungaritidae.

Genetic relationships of Ceratitoidea

^Leiophyllites (Phylloceratidae) 

^Xenaspis >Gymnites >(Pinacoceratidae) 

Prolecanites >Lecanites > Xenodiscus ^Meekoceras

' =>Paratirolites >Anasibirites > 

Ceratites ^Trachyceratea

I >Circumplicati 

^Hungaritidae

The primar}7 radicle of the Xenodiscidae, and 

therefore of the Ceratitoidea, can be only Prolecanites 

of the Carboniferous, and only some such princely 

form as Prolecanites applanatus Frech 67 could be the 

ancestor of the stately species of Xenodiscus, Ophiceras, 

Meekoceras, and Flemingites, which even in the Lower 

Triassic still show their inheritance of noble blood.

The Xenodiscidae include Paraceltites Gemmellaro, 

of the Permian; Paralecanites Diener, of the Permian 

and Lower Triassic; Lecanites Mojsisovics, of the Permian (?) and Lower and Middle Triassic; Proavites 

Arthaber, of the Lower Triassic; Xenodiscus Waagen, 

of the Permian and Lower and Middle Triassic (including as subgen era Xenaspis Waagen, of the Permian and 

Lower Triassic; Genodiscus Smith 68 and Paratirolites 

Stoyanow of the Lower Triassic); Ophiceras Griesbach 

and Flemingites Waagen, of the Lower Triassic. The 

probable relationship of these genera is shown above.

Celtites and its kindred are omitted from the list, as 

they are now known to be derivatives from the stock 

of Gastrioceratea, and to be the probable ancestors of 

the Tropitidae.

Paraceltites, contrary to the opinion of Gemmellaro 

and of Diener and in accordance with that of Frech,69 

is removed from the Tropitidae and placed in the Xenodiscidae. It is clearly a ceratitoid and may even be 

synonymous with Paralecanites, as Frech thought. It 

gives a connecting link with the true Prolecanitidae of j 

the Carboniferous, but none with the Tropitoidea.

Xenodiscus and its kindred are segregated in the 

family Xenodiscidae, though Arthaber 70 puts them in 

the Ptychitidae and under the suborder Tornoceratea.

67 Holzapfel, E., Die Cephalopoden-fiihrenden Kalke des unteren Carbon von 

Erdbach-Breitscheid bei Herborn: Paleont. Abh., n. F-., Band 1, p. 43, pi. 5, fig. 1, 

1889.

08 Genodiscus Smith, n. subgen., type Xenodiscus lidacensis Welter (Die Ammoniten der unteren Trias von Timor: Palaeontologie von Timor, Lief. 11, Abh. 19, p. 

108, pi. 159, figs. 5-7, 18= Celtites fortis Koken). [Professor Smith did not supply a 

diagnosis for this subgenus. Editor.]

69 Frech, Fritz, Die Dyas: Lethaea geognostica, Teil 1, Das Palaeozoicum, Band 2, 

Lief. 4, p. 634, 1902.

'o Arthaber, O. von, Die Trias von Albanien: Beitr. Palaontologie Oesterr.-Ungarns 

u. des Orients, Band 24, p. 227, 1911.

The immediate family radicle, Xenodiscus, has been 

variously treated. Waagen, who named it, placed it 

under the Tropitidae. Arthaber 71 assigns this genus 

to the Ptychitidae, whereas Ophiceras was chosen by 

him as the radicle of the Meekoceratidae. Mojsisovics,72 with his usual acumen, assigns Xenodiscus to the 

meekoceran stock. Diener 73 says that Xenodiscus 

was the radicle of Meekoceratidae and Ceratitidae but 

that Ophiceras must have been the immediate ancestor 

of Meekoceras and that another branch of Ophiceras 

developed into Flemingites; also that some species of 

Flemingites may have come directly from Xenodiscus.

The original home of the Xenodiscidae and Meekoceratidae was in the Indian Ocean or oriental region, 

from which in the Genodiscus epoch they spread outward to achieve nearly world-wide distribution in the 

zone of Pseudosageceras multilobatum (the Flemingites 

or Fledenstroemia zone of India) in every region except 

the Mediterranean. They were present and abundant in the Arctic, oriental, and western American 

regions, in great variety of genera and species, far 

surpassing their kinsmen and contemporaries the 

Pronoritidae, the only other race with an unquestioned 

family genealogy continuous from the Paleozoic into 

the Mesozoic.

This is the most definitely continuous line of ammonoids, connected by Paraceltites, Paralecamtes, and 

Lecanites with Prolecanites of the Carboniferous. It 

was abundant in the oriental region throughout the 

Permian and Lower Triassic, merging into the Meekoceratidae and finally into the Ceratitidae. Then onward its course is secure, as the Lytoceras-Phylloceras 

stock, through the Jurassic and Cretaceous, to the end 

of the Mesozoic and the end of the race. It is probable that the aristocratic Sageceratidae and the somewhat more humble Tropitidae had an equally dramatic history, but through the vicissitudes of migration from one region to another their family records 

have been lost, and only part of them have been 

recovered.

Arthaber 74 is quite positive that Ophiceras and 

Xenodiscus have no genetic relationship and that they 

even belong to different families. Diener,75 on the 

other hand, regards the two genera as almost synonymous, and although he recognizes Ophiceras, he emphasizes the uncertainty in assigning species to one or the 

other genus. The writer agrees with him completely, 

and so apparently do most other students of Triassic

71 Arthaber, G. von, Die Trias von Bithynien (Anatolien): Beitr. Palaontologie 

Oesterr.-Ungarns u. des Orients, Band 27, p. 106, 1914.

72 Mojsisovics, E. von, Das Oebirge um Hallstatt; Die Cephalopoden der Hallstatter Kalke: K.-k. geol. Reichsanstalt Wien Abh., Band 6, Supplement-Heft, p. 

325, 1902.

73 Diener, Carl, Die marinen Reiche der Triasperiode: K. Akad. Wiss. Wien 

Denkschr., Band 92, p. 497, 1916.

74 Arthaber, G. von, Die Trias von Bithynien (Anatolien): Beitr. Palaontologie 

Oesterr.-Ungarns u. des Orients, Band 27, p. 106, 1914. 

" Diener, Carl, op. cit. (Die marinen Reiche der Triasperiode), p. 497.
PHYLOGENETIC CLASSIFICATION 31

paleontology, as shown in the somewhat haphazard 

way in which some authors shift these species back and 

forth. The studies of Frech and of Kraft't went a long 

way toward simplification of the classification of this 

group. We have reason to be deeply grateful to them 

nnd to Inment their untimely death. Another generation of sirnplifiers is badly needed, for Diener has 

carried on the fight almost alone. Now he too is gone, 

the greatest figure and most stabilizing influence we 

have had in the study of Triassic paleontology and 

stratigraphy.

Family MEEKOCERATIDAE

. This name Meekoceratidae is not used here in the 

sense in which it was used by Arthaber,76 who had 

expanded the family to take in forms not admitted b}^ 

Waagen nor by most other writers. As here restricted, 

the family includes Meekoceras Hyatt, Clypeoceras 

Smith ( = As'jridites Waagen), Prionites Waa.gen, Dagnoceras Arthaber, Kashmirites Diener, Anasibirites 

Mojsisovics + Goniodiscus Waagen, Epiceltites Arthaber, 

and Cuccoceras Diener. A.11 these genera are too closely 

related to be grouped in subfamilies. All are apparently derived from Xenodiscus, though probably from 

different species and possibly even from different 

groups of that genus.

The subfamily Lecanitinae is eliminated, Lecanites 

being transferred to the Xenodiscidae, and Ambites, 

Kymatites, Parakymatites, and Proavites also find their 

place in the same family, unless they fall into the 

oblivion of synonymy the first three being possibly 

merely species of Meekoceras that have lost the serrations of the septa through etching or weathering and 

Proavites being possibly a synonym of Lecanites. 

Diener 77 prefers to use the name Proavites for the 

so-called Lecanites of the Lower Triassic, believing 

these forms not to be congeneric with the degenerate 

type of the Upper Triassic. However, as the writer 

.lias a continuous line of species all the way through 

from the Permian to the top of the Middle Triassic, 

he considers Lecanites a retarded genus and not a degenerate. The Hungaritinae are eliminated, because 

they form an independent family, in parallel development with the Xenodiscidae, from Lecanites.

The Arctoceratinae are omitted because Arctoceras, 

as the writer has shown,78 is merely a synonym of 

Meekoceras, and Dagnoceras is too closely allied with 

Meekoceras, though in parallel development, to be 

separated from it. The young of Dagnoceras show 

close relationship to Anasibirites. Ophiceras is put 

back in its old position near Flemingites under the

; ° Artlmbor, 0. von, 'Die Trias von Albanien: Beitr. PalSontologie Oesterr. 

Ungarns u. clcs Orients, Band 24, p. 23G, 1911.

" Krnu't, A. von, nnd Diener, Carl, Lower Triassic Cephalopoda from Spiti, 

Miillu Johiir, nnd Bynns: India Geol. Survey Mem., Palaeontologia Indica, loth 

scr., vol. 0, Mem. 1, p. "3, 1909.

'S Smith, J. P., The Middle Triassic marine invertebrate faunas of North America: 

U. S. Oeol. Survey Prof. Paper S3, p. 77, 1914.

Xenodiscidae. Beyrichites is returned to the Ceratitidae, because of its close relationship to Ghjmnotoceras 

and the Geminati, as derivatives from Anasibirites. 

Philippites also is not included as a synonym of Prionites for the same reason, although it may be a descendant of that genus.

Anasibirites is included under the Meekoceratidae 

because it and its subgenus Goniodiscus show a development from a ribbed Xenodiscus and bear no resemblance in the young stages to the Gastrioceratea 

but in age revert to meekoceran or Xenodiscus-\ike 

forms. It is noteworthy as the probable ancestor of 

at least some of the groups classed under Ceratites.

In harmony with Diener,79 Kashmirites is introduced 

as a probable ancestor of Anasibirites and descendant 

of Xenodiscus. The young stages of Kashmirites show 

very decided resemblances to Paratirolites, which is 

regarded as a subgenus under Xenodiscus.

Proptychites is excluded, in spite of the impossibility 

of separating some of its forms from Meekoceras. 

Many species assigned to Proptychites should more 

properly be given to Acrochordiceras, which, in agreement with Diener,80 is now admitted to the Meekoceratidae. Diener would derive Proptychites (Sibirites} 

( Anasibirites} and Hedenstroemia from Meekoceras, 

with which the writer agrees in part; Diener would 

further derive Hollandites and Acrochordiceras from the 

same source, with which the writer does not agree. 

He rather regards all the Circumplicati Hollandites 

and Philippites as derivatives of Anasibirites, and 

Acrochordiceras as a descendant of the same stock.

In agreement with Diener 81 the writer accepts 

Xenodiscus as the family radicle of Meekoceratidae, 

for all the principal members of that family show distinct Xenodiscus stages of growth and before that 

resemble Lecanites or Paralecanites.

Clypeoceras continues unchanged (under the name 

 Aspidites) ?* and even Prionites is still visibly present 

in the Muschelkalk under the name Hollandites, with 

but slight modification. We have, then, sufficient 

overlapping between Meekoceratidae and Ceratitidae.

Family CERATITIDAE

The writer 83 has already published a full account of 

the classification and phylogeny of the Ceratitidae, in 

so far as they are represented in the American faunas 

or were known up to 1914. Since that time many 

discoveries have been made and additional publications issued, necessitating some changes in our ideas 

of the phylogenetic arrangement of the genera of the

79 Diener, Carl, Die marinen Reiche der Triasperiode: K. Akad. Wiss. Wien 

Denkschr., Band 92, p. 49S, 1916.

60 Idem, pp. 497-49S.

51 Idem, p. 497.

» Arthaber, G. von, Die Trias von Bithynien (Anatolieu): Beitr. Paiaontologie 

Oesterr.-Ungarns u. des Orients, Band 27, p. 243, 1914.

53 Smith, J. P., The Middle Triassic marine invertebrate faunas of North America: 

U. S. Geol. Survey Prof. Paper S3, pp. 68-121, 1914.
32 LOWER TRIASSIC AMMONOIDS OF NORTH AMERICA

Ceratitidae. These publications are especially Arthaber's work on the Trias of Bithynia, 84 Diener's series 

of monographs that have thrown so much light on 

Triassic stratigraphy and paleontology,85 and the two 

monographs by Welter 86 on the Triassic cephalopods 

of Timor. The genera admitted to the Ceratitidae in 

the restricted sense are Ceratites De Haan (Nodosi) 

(subgenera Paraceratites Hyatt, Semiornites Arthaber, 

and Kellnerites Arthaber), Hollandites Diener and 

Philippites Diener (Circimiplicati), Acrochordiceras 

Hyatt, Frechites Smith, n. gen., Gymnotoceras Hyatt, 

Haydenites Diener, Beyrichites Waagen (the seven 

genera last mentioned derivatives of Anasibirites), 

Keyserlingites Hyatt (subgenus Durgaites Diener), 

Olenekites Hyatt, Arpadites Mojsisovics, Danubites 

Mojsisovics, Dinarites Mojsisovics, Tirolites Mojsisovics, and Reiflingites Arthaber.

Genus FRECHITES Smith, n. gen.

Type: Ceratites humboldtensis Hyatt and Smith. 87 

The new genus Frechites, which was called by the 

writer 88 in 1905 "group of Ceratites humboldtensis 

Hyatt and Smith," should be given independent 

rank, for it can not be placed under the Nodosi nor 

yet very well under either the Geminati or the Circumplicati. The following description is quoted from 

the work cited.

With strong lateral and marginal tubercles and commonly a 

weak keel ridge. The young of this group resemble Gymnoloceras, and even at maturity the forms show great affinity 

with the Geminati. The septa are usually slightly ammonitic. 

This group has the greatest resemblance to the Germanic 

Nodosi, but this is probably due to convergence or possibly to 

atavism, for the Germanic group seems to have been derived 

directly from Meekoceras. The nearest Mediterranean relative 

appears to be C. subnodosus Mojsisovics. The length of the 

body chamber is more than three-fourths of a revolution, much 

greater than in the group of C. nodosus.

This genus is confined to the Middle Triassic zone of 

Ceratites trinodosus, in western America, where it is 

abundantly represented. The generic name is given 

in memory of that gallant and honorable fighter 

Fritz Frech, with whom nearly every contemporary 

worker had some sort of tilt but who always fought 

fairly.

The supposed phylogeny of the Ceratitidae was 

once extremely simple, the Ceratites being supposed

w Arthaber, O. von, op. cit.

ss Diener, Carl, Die marinen Reiche der Triasperiode: K. Akad. Wiss. Wien 

Denkschr., Band 92, 1916; Ueber Ammoniten mit Adventivloben: K. Akad. "Wisi. 

Wien Denkschr., Band 93, 1917; Ammonoidea Trachytostraca aus Mittleren und 

Oberen Trias von Timor: Jaarboek van het Mijnwezen in Ned. Indie, Verb. 4. 

1920.

so Welter, O. A., Die Obertriadischen Ammoniten und Nautiloiden von Timor: 

Palaeontologie von Timor, Lief. 1, 1914; Die Ammoniten der Unteren Trias von 

Timor: Idem, Lief. 11, Abh. 19, 1922.

a? Hyatt, Alpheus, and Smith, J. P., The Triassic cephalopod genera of America: 

U. S. Geol. Survey Prof. Paper 40, p. 170, pi. 57, figs. 1-23, 1905.

ss Smith, J. P., The Middle Triassic marine invertebrate faunas of North America: 

U. S. Geol. Survey Prof. Paper 83, p. 79, 1914.

to be descended from Dinarites and the Trachyceratea 

from Tirolites. Now, however, those two genera are 

thought by Philippi 89 to be merely retarded or reversionary members of the family and not to be radicles 

an opinion with which the writer agrees. We must 

then, seek for the ancestral stock elsewhere. Nearly 

all writers have turned to the Meekoceratidae and 

disagree only as to the particular genus. Philippi 90 

regards Meekoceras as the ancestor of the Nodosi. 

The writer 91 showed that Meekoceras mushbachanum 

in its development came from Lecanites and Xenodiscus 

and almost reached the stage of evolution of the 

Nodosi. However, we do not know that the Nodosi 

duplicate all that. Arthaber 92 accepts Meekoceras 

as ancestor of Ceratites but declines to accept Xenodiscus as a forebear of Meekoceras; instead, he chooses 

Ophiceras. This choice meets with partial assent 

from Diener,93 who regards Xenodiscus as the radicle 

of the Meekoceratidae and Ceratitidae but thinks 

that Ophiceras was the connecting link between 

Xenodiscus and Meekoceras. Diener 94 would further 

derive the Nodosi from Beyrichites and Hollandites, 

with which the writer can not agree, for the Nodosi 

have ceratitic septa, whereas Beyrichites and Hollandites have ammonitic septa, a reversal of development 

hardly possible in a progressive series.

The writer is now inclined to believe that, although 

the Nodosi may have come directly from Meekoceras, 

the subgenera Paraceratites, Semiornites, and Kellnerites probably were derived from the Genodiscus > 

Kashmirites > Anasibirites stock, as shown by the 

young stages figured by the writer elsewhere. 95 The 

writer further believes that the Geminati and Circumplicati are a parallel development from the same 

stock, as shown by young stages figured in the work 

cited. At the time that paper was published it was 

thought that Kellnerites might be descended from 

Olenekites, but that opinion is now given up, and 

Olenekites itself is regarded as a side branch from the 

Kashmirites > Anasibirites stock. It must be remembered that only a few years ago we knew nothing 

of Kashmirites, and Anasibirites was known only by 

the few fragments described by Waagen from the 

Salt Range. Now we know them as a great worldwide stock, not of Gastrioceratea but of the true 

Meekoceratidae, abundant in the Oriental, western 

American, and Arctic regions, sparingly represented 

even in the Mediterranean.

88 Philippi, E., Die Ceratiten des oberen deutschen Muschelkalkes: Paleont. 

Abh. (Dames & Koken), n. F., Band 4, p. 100, 1901. 

90 Idem, p. 111.

81 Smith, J. P., op. cit. (Prof. Papsr 83), pp. 77, 78. 

92 Arthaber, G. von, op. cit. (Die Trias von Bithynien), p. 106.

83 Diener, Carl, Die marinen Reiche der Triasperiode: K. Akad. Wiss. Wien 

Deukschr., Band 92, p. 457, 1916.

84 Idem, p. 498.

M Smith, J. P., op. cit. (Prof. Paper 83), pp. 72-80.
PHYLOGENETIC CLASSIFICATION 33

TRACHYCERATEA

The Trachyceratea, including Trachyceras Mojsisovics and its allies, were derived by Mojsisovics from 

Tirolites through. Balatonites a very unlikely source, 

according to present knowledge. The writer 96 has 

tried, to show that the Trachyceratea came directly 

from the group of Ceratites haguei Smith (Kellnerites 

Arthaber) through. Nevadites. This source is corroborated, by the development of numerous species of 

Nevadites, Anolcites, Trachyceras, Clionites, and Sirenites. The so-called Tirolites stages of Trachyceras and' 

Clionites are probably only palingenetic forms of 

Paratirolites. This conclusion simplifies matters and 

eliminates the necessity of supposing Trachyceras and 

its allies to be polyphyletic; it is also much more 

probable than the old idea.

Family OYMNITIDAE

The Gymnitidae were first placed by Mojsisovics 97 

under the Ptychitidae, which were then a very heterogeneous assemblage. In a later work 98 he was inclined 

to derive Gymnites from Daraelites, a Permian member 

of the Pronoritidae. Waagen " classed Gymnites 

along with Flemingites and Xenodiscus under the 

family Gymnitidae, which is getting much nearer the 

true relationship. Arthaber 1 agrees with the earlier 

conclusion of Mojsisovics on the derivation of the 

family from Xenodiscus.

The writer 2 has shown that Gymnites alexandrae 

Smith in its youth goes through stages corresponding 

to Xenaspis and confirms the conclusion that Gymnites 

must have originated from the Xenodiscidae.

LYTOCERAS-PHYLLOCERAS STOCK

The Lytoccras-Phylloceras stock has long been a 

puzzle to paleontologists. Mojsisovics 3 attached it to 

the Lytoceratinae as descendants of Lecanites or 

Prolecanites, which comes very close to the modern 

Adew. Zittel 4 derives the Phylloceratidae from the 

Cyclolobidae and therefore, by inference, from the 

Gastrioceratea. Haug 5 traced them back to Nomism,oceras, which is now commonly assigned to the 

Glyphioceratidae. Hyatt 6 derived the "Phyllocampyli" from the Prolecanitidae, a rather vague derivation. The first definite intimation of their correct

««Idem, pp. 121-137.

0? Mojsisovics, E. von, Die Cephalopoden der M'editerranen Triasprovinz: TC.-k. 

gcol. Keichsanstalt Wien Abh., Band 10, p. 231, 1882.

M Mojsisovics, IE. von, Das Qebirge um Hallstatt; Die Cephalopoden der Hallsttitter Kalke: K.-k. geol. lleichsanstalt Wien Abh., Band 0, Supplement-Heft, p. 

302, 1002.

00 Wangon, W., Fossils from the Ceratite formation: India Qeol. Survey Mem., 

Pnlaeontologia Indica, 13th ser., Salt Range fossils, vol. 2, p. 162, 1895.

' Arthaber, Q. von, Die Trias von Albanien: Beitr. Palaontologie Oesterr.- 

Ungiirns u. des Orients, Band 27, p. 229, 1911.

z Smith, J. P., op. cit. (Prof. Paper 83), p. 51.

3 Miojsisovics, E. von, Die Cephalopoden der Mediterranen Triasprovinz: K.-k. 

gcol. Ttoiehsanstalt Wien Abh., Band 10, p, 204, 1882.

* /ittol, K. A. von, Grundziigo der Palaeontologie, Abt. 1, p. 567, 1924.

» Haug, E., Etudes sur les Qoniatites, p. 48, 1898.

0 Hyatt, Alpheus, Cephalopoda, iu Eastman's translation of Zittel's Textbook 

of paleontology, vol. 1, p. 591, 1900.

position in the family line is from Arthaber, 7 who 

classifies Monophyllites along with Xenodiscus, although 

in the text he refrains from declaring the one to be 

descended from the other. The writer has had under 

study three of Arthaber's species, from the Lower 

Triassic of Timor Leiophyllites kinyi Diener, L. dieneri 

Arthaber, and L. pitamaha Diener. They are definitely transitional from Xenaspis to Monophyllites and in 

early youth show perfect Xenaspis stages. Still 

younger stages show a marked resemblance to Prolecanites. The genus Palaeophyllites Welter, from the 

Lower Triassic of Timor, seems to be a further step 

upward toward RhacophyUites, both in sculpture and 

in septation, and shows that the Phylloceratidae were 

already well established in fairly typical development. 

The writer has studied the young of Discophyllites 

patens Mojsisovics, from the Upper Triassic of California,8 and finds that in the adolescent stage this 

species is a perfect replica of Monophyllites. Also the 

larval stage of Phylloceras ramosum, of the Upper 

Cretaceous of California, resembles Prolecanites, 

whereas the early adolescent stages duplicate Monophyllites and- Discophyllites. This would seem to 

show conclusively the persistence of the derivatives 

of the Xenodiscidae with easily recognizable characters from the Paleozoic to the end of the Mesozoic.

In recent years paleontologists have been prone to 

derive all Jurassic and Cretaceous ammonites from 

the Phylloceras stock, although they fail to show in 

their development any reminiscences of either Xenodiscidae or Phylloceras. It is rather remarkable that 

these Jurassic and Cretaceous forms should have lost 

their ancestral history so utterly, while Phylloceras 

should havre retained it so clearly expressed. The 

writer has always had very grave doubts as to the 

correctness of the commonly accepted idea, but this 

must be decided by students of Jurassic and Cretaceous 

genera.

Family PINACOCERATIDAE

This outline has shown how the old family of Pinacoceratidae has been broken up, some members being 

assigned to the Pronoritidae, some to the Sageceratidae, 

some to the Haneritidae, and others given back to 

the enlarged gens of the Ceratitidae. But Pinacoceras 

and its immediate kin have been left somewhat 

stranded. Mojsisovics 9 had already indicated that 

the genus probably came from Gymnites. Arthaber I0 

is inclined to follow him in this conclusion, which is 

definitely corroborated by Diener. 11

7 Arthaber, O. von, op. cit. (Die Trias von Albanien), p. 232.

8 Smith, J. P., Upper Triassic marine invertebrate faunas of North America. 

U. S. Oeol. Survey Prof. Paper 141, 1927.

11 Mojsisovics, E. von, Das Qebirge um Hallstatt; Die Cephalopoden cler Hallstatter Kalke: K.-k. geol. lleichsanstalt AVien Abh., Band 6, Supplement-Heft, p. 

293, 1902.

1° Arthaber, G. von, Die Trias von Bithynien (Anatolien): Beitr. Pala'ontologie 

Oesterr.-Ungarns u. des Orients, Band 27, p. 155, 1914.

11 Diener, Carl, Ueber Ammoniten mit Adventivloben: K. Akad. Wiss. Wien 

Denkschr., Band 93, p. 187, 1917.
34 LOWER TRIASSIC AMMONOIDS OF NORTH AMERICA

With the eliminations noted above the Pinacoceratidae become a homogeneous group, quite definitely 

placed in the phylogonetic scheme. Diener has shown 

conclusively, in the work cited above, that the development of adventitious lobes, the character once 

thought most significant in defining this family, has 

come about wholly independently in many different 

stocks and is therefore of little taxonomic value.

Family HUNGARITIDAE

The Hnngaritidae have usually been placed under 

the Ceratitidae in the broader sense, or immediately 

next to them. But Arthaber 12 and following him 

the writer 13 transferred a genus of this family, Longobardites Mojsisovics, to the Pinacoceratoidea because 

of the development of adventitious lobes. Diener u 

later restored Longobardites to its proper place.

However, the Hungaritidae should not be put under 

the Ceratitidae, even though some members of the 

two families in the Middle Triassic have been confused, nor should they even be regarded as derivatives 

of the typical Xenodiscidae. The Hungaritidae began 

their record with Dalmatites in the lower Permian, as 

a derivative from Prolecanites, and continued as 

Otoceras and Hungarites in the Lower Triassic and 

further as Hungarites, .Eutomoceras, and Halilucites in 

the Middle Triassic. The Lecanites stage is known in 

the young of Dalmatites, Longobardites, and Eutomoceras, in the collection of the writer. We do not 

know that they lived into Upper Triassic time, 

although some of the specialized forms with adventitious lobes in that epoch may well have been derived 

from Longobardites. The so-called Eutomoceras of 

the Upper Triassic is a tropitoid, as shown by Hyatt 

and Smith, 15 and has been renamed Discotropites.

Superfamily BELOCERATOIDEA

The Beloceratoidea, as here defined, are restricted 

to Beloceras Hyatt and Timanites Mojsisovics, of the 

Devonian; Prodromites Smith and Weller and fAcrocanites Schindewolf, of the Carboniferous; Pseudosageceras Diener, Sageceras Mojsisovics, and Aspenites 

Hyatt and Smith, of the Triassic. It includes only 

forms that appear to be closely related to Beloceras 

and is therefore an exceedingly limited group. It is 

much less inclusive than Beloceratea, as expanded 

by Arthaber 16 to contain all forms with adventitious 

lobes, thus taking in the Pronorites-Medlicottia group, 

the Thalassoceras-Ussuria stock (the Di7norphoceras 

group), and the Carnitidae, which are a mixture of

12 Arthaber, G. von, Die Trias von Albanien: Beitr. Pala'ontologie Oesterr.- 

Ungarns u. des Orients, Band 24, p. 20C, 1911.

13 Smith, J. P., The Middle Triassic marine invertebrate faunas of North America: 

U. S. Qeol. Survey Prof. Paper 83, p. 50, 1914.

" Diener, Carl, op. cit. (Ueber Ammoniten mit Adventivloben), p. 177.

15 Hyatt, Alpheus, and Smith, J. P., The Triassic cnphalopod genera of America:' 

U. S. Geol. Survey Prof. Paper 40, p. 61, 1905.

i" Arthaber, G. von, op. cit. (Die Trias von Albanien), pp. 128 et seq.

Procarnites (probably from the Dimorphoceras stock), 

Carnites and Longobardites (almost certainly from the 

Hungarites stock), and Hedenstroemia which is probably 

a derivative of Meekoceras.

It includes part, but only a very small part, of what 

Mojsisovics, Waagen, Diener, and the writer formerly 

called Pinacoceratoidea or Pinacoceratidae, but the 

genera included have no kinship with that family. 

The writer 17 has already expressed his doubts as to 

the value of adventitious lobes in taxonomy but continues to use the accepted nomenclature for the sake 

of uniformity. Mojsisovics 18 also questioned the 

value of adventitious lobes in classification of ammonite 

genera.

The sharpest and almost the only criticism of this 

basis of taxonomy has been given by Diener, 19 who 

has disrupted the supposed phylum entirely and left 

in it only the genus from which the name is taken. 

The writer agrees with Diener in most of this drastic 

procedure, but not as to the removal of Pseudosageceras, Sageceras, and Aspenites, for he has young 

stages of all three forms, at diameters of 4 to 5 millimeters, which show a very striking resemblance to 

Beloceras and the very early development of adventitious lobes. Diener would derive these three genera 

from Meekoceras, but the writer has examined the 

young stages of numerous species of that genus and of 

kindred genera in the Meekoceratidae and finds that 

they all resemble Xenodiscus and back of that Prolecanites and Lecanites and do not have the faintest 

likeness to the young of the Sageceratidae.

Meekoceras and its kindred were doubtless an exceedingly potent stock, but the writer can hardly agree that 

they are the parents of nearly all the Triassic ammonites outside the Gastrioceratea.

The details of the young stages of Pseudosayeceras, 

Sageceras, and Aspenites will be given in full under the 

discussion of the Carnitidae. This supposed family 

comes under discussion here only because Arthaber 20 

has united under this name Ussuria, Procarnites, and 

Carnites. The genus Ussuria has been shown by the 

writer 21 to belong definitely to the DimorphocerasThalassoceras stock, whereas the two other genera of 

the group are said by Diener 22 to be derived from 

Meekoceras. The writer agrees with him partly, as to 

Carnites, for the young stages already figured by 

Mojsisovics tell the same story of relationship to either 

Hungarites or Meekoceras. But the young stages of 

Procarnites are not known, and the adult stages are so 

remarkably like Ussuria that it would seem there must 

be some real relationship.

i? Hyatt, Alpheus, and Smith, J. P., op. cit. (Prof. Paper 40), p. 99.

1S Mojsisovics, E. von, Das Gebirge um Hallstatt; Die Cephalopoden der Hallstiitter Kalke: K.-k. geol. Reichsanstalt Wien Abh., Band 6, Supplement-Heft, p. 

309, 1902.

19 Diener, Carl, op. cit. (Ueber Ammoniten mit Adventivloben), pp. 164-194.

20 Arthaber, G. von, op. cit. (Die Trias von Albanien), p. 211.

« Hyatt, Alpheus, and Smith, J. P., op. cit., p. 88.

22 Diener, Carl, op. cit. (Ueber Ammoniten mit Adventivloben), p. 167.
PHYLOGENETIC CLASSIFICATION 35

Superfamily DIMORPHOCERATOIDEA 

Family THAIASSOCERATIDAE

Thalassoceras is known only in a few species, from 

the lower Permian of Texas, Timor, the Urals, and 

Sicily. In Sicily Gemmellaro 23 has described T. 

microdiscus as going through a stage corresponding to 

Dimorphoceras. The writer 2<1 has specimens that show 

the young stages of Ussuria waageni going through 

stages corresponding to Dimorphoceras, Thalassoceras, 

and typical .Ussuria, successively, before reaching a 

higher subgeneric stage. Some of these are figured and 

described, in the present paper.

Along with Ussuria the writer would further include 

Sturia IVfojsisovics, in agreement with Mojsisovics, 25 

although the young stages are entirely unknown. 

This genus appears in the Lower Triassic, shortly after 

Ussuria, without any other possible kinsmen, and 

would seem to fit in better with this group than with 

any other.

This statement applies also to Procarnites Arthaber, 

as stated in the preceding section under Carnitidae. 

Their reception here is therefore only tentative. 

Otherwise they are homeless.

Family HAUERITIDAE

The members of the Haueritidae were included by 

Arthaber 20 in the somewhat heterogeneous group 

Carnitidae. As restricted here only Lanceolites Hyatt 

and. Smith, Frcmontites Smith, Hauerites Mojsisovies, 

Klamathites Smith, and doubtfully Arthaberites Diener 

are included. It is shown above,.under the Carnitidae, why Ussuria, Procarnites, and Carnites are 

separated and why the family itself has been rejected.

Mojsisovics 2T regarded Hauerites as a subgenus of 

Cyrtopleurites from some member of the Ceratitoidea 

allied to Gymnotoceras. The writer, however, basing 

his opinion on the young stages of Lanceolites and 

Fremontites and upon good adult specimens of Klamathites studied by him, thinks that here we have a 

compact family in no way connected with the groups 

to which they have been assigned. This family has 

been named by him Haueritidae. 28 The young of 

Lanceolites at a diameter of about 4 millimeters are 

perfect replicas of Amphyllites; then at a diameter of 

about 5 millimeters they resemble Dimor2)hoceras 

slightly but without the secondary division of the 

external lobe, thus corresponding either to some unknown genus of the Carboniferous or to some unknown

!S Qominollnro, 0. 0., Ln fauna del calcari con Fusulina delln Valle del Fiume' 

Sosio nella provincia di Palermo, p. 72, 3887.

2 ' Hyntt, Alpheus, and Smith, J. P., op. cit. (Prof. Paper -10), p. 88.

"Mojsisovics, E. von, Die Cephalopoden der Hallsta'tter Kalke: K.-k. geol. 

.Kcichsanstalt \Vien Abh., Band 0, Supplement-Heft, p. 306,1C02.

"> Arthaber, 0. von, op. cit. (Die Trias von Albanien), p. 211.

87 Mojsisovics, E. von, Die Cephalopoden der Hallsta'tter Kalke: K.-k. geol. 

Kcichsanstalt AVicn Abh., Band 6, B'alfte 2, p. 517, 1893.

2 ' Smith, .1. P., Upper Triassic marine invertebrate faunas of North America: 

U. S. Ocol. Survey Prof. Paper 141, p. 72, 1927.

species of Dimorphoceras. It may be that Neodimorphoceras Schmidt will give us the needed form, 

though it is not likely. At this stage the lateral lobe 

begins to be slightly serrated. At maturity the adventitious lobes are not yet really developed but can 

already be foreseen in the divisions of the external lobe.

At the Karnic horizon of the Upper Triassic appears 

Fremontites, which in youth shows decidedly these 

same stages and then subdivides the lobes more deeply, 

becoming much more like Hauerites, which occurs at 

the same horizon. A little higher up, toward the top 

of the Karnic, there appears the genus Klamathites 

with the same shape and with the same ground plan 

of septation but with much greater complication of 

division and development of the adventitious lobes.

Arthaberites Diener 29 may be the Middle Triassic 

intermediary between Lanceolites and Fremontites but 

is too little known for certain decision. The young 

stages of Hauerites itself have not been published, but 

the kinship with Lanceolites and Fremontites is beyqnd 

doubt, and their ontogeny, so completely unlike that 

of the Meekoceratidae and so consistent, assigns them 

to a uniform group. They are therefore placed as a 

branch of the Gephyroceratea, in parallel development 

with the Thalassoceratidae but not from the same 

primary radicle not from Dimorphoceras but from 

some genus closely allied to it. The Haueritidae are 

not allied to Carnites and Metacarnites, which are 

referred to the meekoceran stock, nor to Tibetites, 

Cyrtopleurites, and Bambanagites, which are now placed 

in the Ceratitoidea as probable branches from the 

Hungarites phylum.

Superfamily PRONORITOIDEA 

Family PRONORITIDAE

Karpinsky 30 has proved definitely that Medlicottia 

and its kinsmen came from Pronorites, though he was 

mistaken in deriving that genus from the mythical 

" Iberfjiceras," which Holzapfel has since shown to be 

merely a young stage of Pronorites itself. None the 

less Karpinsky's great work is the most satisfactory 

and convincing exposition of recapitulation of the 

Ammonoideja yet brought forward, the model and 

the despair of all students of ammonite phylogeny. 

Simplex munditiis.

Bose 31 shows clearly that Uddenites Bose goes 

through a distinct Pronorites stage, although he 

thought it to be merely an insignificant side branch 

from the main stock. Another side branch gave us 

Daraelites, from which probably came Albanites of 

the Lower Triassic, and through that genus the

20 Arthaber, G. von, op. cit. (Die Trias von Albanien), p. 217, fig. 9.

so Karpinsky, A., Ueber die Ammoneen der Artinsks-Stufe und einige mit denselben verwandten carbonischen Formen: Acad. imp. sci. St.-Pfitersbourg Mem., 7th 

ser., vol. 37, No. 2, 1889.

31 Bose, Emil, The Permo-Carboniferous ammonoids of the Glass Mountains, 

west Texas: Texas Univ. Bull. 1762, p. 55, 1917.
36 LOWER TRIASSIC AMMONOIDS OF NORTH AMERICA

Noritidae of the Middle Triassic. The writer 32 has 

tried to show that Cordillerites Hyatt and Smith, of 

the Lower Triassic of Idaho, goes through a Pronorites 

stage in its youth. But Diener 33 refuses to accept this 

conclusion and instead would derive Cordillerites from 

Meekoceras. The writer has examined anew the young 

stages of Cordillerites and still finds them like Pronorites, without any resemblance to Meekoceras and 

the Xenodiscidae, with the very early development of 

the angulate whorl and adventitious lobes. These do 

not form from the external saddle in Cordillerites, as 

they are said to do in Medlicottia, but from the external lobe. The formation of the adventitious lobes 

is an inherent, hereditary character, not late and cenogenetic, as in Fledenstroemia.

The genera now admitted to the Pronoritidae are 

Pronorites Mojsisovics (Carboniferous and Permian), 

Parapronorites Gemmellaro, Medlicottia Waagen (subgenera Episageceras Noetling, Propinacoceras Gemmellaro, and Artinskia Karpinsky), Sicanites Gemmellaro, Uddenites Bose, Sundaites Haniel, Daraelites 

Gemmellaro, Albanites Arthaber, and Cordillerites 

Hyatt and Smith. All these forms are confined to the 

Paleozoic, except Episageceras, which ranges up into 

the Lower Triassic, and Albanites and Cordillerites, 

which are confined to the Lower Triassic.

GASTEIOCERATEA

The clan Gastrioceratea as here defined includes the 

Gastrioceratea as defined by Arthaber 34 but is more 

extensive, taking in also his Agathiceratea as derivatives of Gastrioceras. It also includes Ptychitidae 

s. s., exclusive of the Gymnitidae, which are now 

placed under the Prolecanitoidea of the Gephyroceratea.

The Gastrioceratea have a prevailingly long body 

chamber and robust whorls. The sculpture is highly 

developed in the Tropitidae, less so in the Haloritidae, 

and nearly lacking in the Arcestoidea. The septa 

range from simply goniatitic (Gastrioceras, Agathiceras, and Celtites), through nearly ammonitic (Marathonites, Protropites, and Columbites), to highly complex 

ammonitic (Tropites, Plalorites, Juvavites, Waagenoceras, and Arcestes).

It is certain that before the end of the Permian the 

Gastrioceratea had branched out into two phyla 

Arcestoidea and Tropitoidea and that the latter had 

already begun to divide into two families the Celtitidae, forerunners of the Tropitidae, and the Haloritidae.

The Arcestoidea are nearly world-wide in the Permian, as Agathiceras, Adrianites, Shumardites, Marathonites, Perrinites, Waagenoceras, and a few other less

32 Hyatt, Alpheus, and Smith, J. P., The Triassic cephalopod genera of America: 

TJ. S. Geol. Survey Prof. Paper 40, pp. 109-113, pis. 2, 68, 71, and 75, 1905.

33 Diener, Carl, op. cit. (Ueber Ammoniten mit Adventivloben), p. 175. 

« Arthaber, G. von., op. cit. (Die Trias von Albanien), p. 179.

common genera, all members of the highly accelerated 

Cyclolobidae, descendants of the group of Gastrioceras 

globulosum.

The Haloritidae are known as" yet in the Permian 

only in the doubtful Hoffmannia of Sicily and in the 

rare Timorites Haniel, which is the predecessor but 

probably not the ancestor of the Triassic members of 

this stock. Its value lies only in showing the continuity of the race.

The Tropitidae are known as yet in the Permian 

only as a continuation of the main line in ParagastrioceraSj for Xenodiscus and Paraceltites have been 

dropped from the family, as shown above.

No Gastrioceratea are known in the uppermost 

Permian anywhere, nor in the lowest beds of the 

Lower Triassic, until the reappearance of the Arcestoidea in Prosphingites, the most primitive member of the 

Arcestidae, in the American, Indian, and Arctic 

regions. Bonnet 35 cites Gastrioceras abichianum from 

the Lower Triassic of Armenia, a find which is improbable and has not been verified.

Superfamily TROPITOIDEA 

Family CELTITIDAE

The most primitive group of Tropitoidea is the 

family Celtitidae, here restricted to Celtites Mojsisovics, 

Columbites Hyatt and Smith, and Arnautoceltites 

Diener. Xenodiscus and Paraceltites have been 

dropped from the family and referred to the Xenodiscidae, under the Ceratitoidea.

No Celtitidae are known anywhere below the 

Columbites zone of the Lower Triassic, but there they 

appear abundantly in the Mediterranean (Albanian) 

and western American regions and doubtfully in the 

Arctic region. It may be that the Arctic region was 

their original home and that they persisted there 

during the lost interval, to reappear as Celtites and 

Columbites in western America and as Columbites and 

Protropites in Albania. This reappearance looks like 

the result of a possible radial migration southwestward 

through the depression along the Ural Mountains to 

Albania and southeastward through the marginal sea to 

western America. At any rate they lived on somewhere, certainly not in the Indian region, in which the 

Tropitidae appear to be lacking until Upper Triassic 

time.

In this feature the contrast with the history of the 

Gephyroceratea is strong. That group, which includes 

Xenodiscidae and Pronoritidae, is clearly radial from 

the Indian region, abundant in the Permian and Lower 

Triassic, with continuous series of both stocks, reaching 

out as immigrants to other regions.

Celtites Mojsisovics is the most likely connecting 

link between the Tropitidae and their gastrioceran 

ancestry, although it may be a side branch and not

35 Bonnet, P. N., Sur une mission en Transcaucasie (1911): Soc. gfiol. France 

Compt. rend., Ann6e 1912, p. 115.
PHYLOGENETIC CLASSIFICATION 37

the main line. This genus has been assigned by 

many writers to the Ceratitoidea, because of mistaken notions as to its kinship with Xenodiscus and 

Paraceltites. Also, until recently, it has been known 

only as a degenerate group in the Middle and Upper Triassic. The species described by Waagen from 

the Lower Triassic of India have been transferred 

to Xenodiscus and Kashmirites because of their short 

body chamber and strongly serrated lobes. Those 

species described from the Salt Range of India by 

Koken ;io "Celtites" Jortis and "C." radiosus are 

placed in a new subgenus of Xenodiscus. Epiceltites 

Arthaber is placed under the Anasibirites group, and 

Celtites arnauticus Arthaber,37 from the Lower Triassic of Albania, has been renamed "Arnautoceltites" 

by Diener 38 and is probably a very primitive offshoot of the gastri.oceran stock, retarded in those

 characters and. not up to the development of Celtites. 

However, three genuine species of Celtites are known 

in the Columbites fauna, near the top of the Lower 

Triassic of Idaho. These species Celtites ursensis 

Smith, C. planovolvis Smith, and C. apostolicus Smith, 

are little-modified derivatives of Paragastrioceras 

Tchernow. They have gastrioceran septa, long body 

chambers, periodic constrictions, trapezoidal cross-

 sections, rather well-defined spiral lines on the shell, 

and, in the youthful stages, the broad-flattened whorl 

and. umbilical nodes of typical Gastrioceras. In fact, 

they differ from that genus only in the bifid antisiphonal lobe, in the greater evolution and slenderness of the whorls, and in the reduction of sculpture 

at maturity. These species tend to bridge over the 

gap in the history of the Tropitidae that formerly 

existed from the upper Permian to the Middle Triassic. We may confidently expect to find true 

Celtites all through the Lower Triassic and down to 

the middle Permian, overlapping with Paragastrio-

 ceras.

From Celtites the steps upward are easy and natural, and the genealogy of the Tropitidae is simple. 

Columbites is probably a connecting link between 

the Tropitidae of the Triassic and the Glyphioceratidae of the Carboniferous. For a long time Celtites 

has been regarded by some paleontologists as the 

ancestor of the Tropitidae, in spite of the fact that 

no certain members of the Tropitidae were known to 

have young stages resembling Celtites. This view was 

held because the ontogeny of the Tropitidae points 

to an evolute ancestor with long body chamber and 

lateral ribs and destitute of keel and abdominal furrows. Columbites meets these requirements and is 

like the young stages of the more primitive members

3° Noetling, Fritz, Die asiatischo Trias: Lethaea gcognostica, Toil 2, Das Meso- 

/.oicuiii, Basic! 1, Trias, .Lief. 2, pi. 22, figs. 1, 2, and explanation of plate, 1005.

" Arthnber, O. von, op. cit. (Die Trias von Albanian), p. 206.

is .Dienor, Carl, Netic Tropitoidea: Akad. Wiss. Wion Denkschr., Band 97, 

p. 512, 1910.

of the Tropitidae, whereas Celtites is somewhat retrograde and almost too primitive to be the radicle. 

Columbites is apparently tending directly toward the 

Tropitidae. In its youth it is decidedly like Gastrioceras and Paragastrioceras, and in adolescence it 

takes on the serrations .of the lobes. The development of two species of this genus has been fully described by the writer,39 and the young stages of C. 

parisianus Hyatt and Smith and of C. spencei Smith 

are fully figured, with detailed comparisons with 

Gastrioceras. In 1911 Arthaber 40 described from Albania several species of Columbites, which appear to 

approach Tropites more nearly than the American 

species do, in spite of his somewhat adverse opinion. 

At that time Arthaber could not know of the intergradation of Columbites and Tropigastrites, which 

was. not published until 1914 and consequently was 

inaccessible to him for several years.

The writer does not mean to assert that any known 

species of Columbites in either the American or the 

Albanian fauna was the ancestor of Tropites but 

that something like a Columbites certainly was.

Columbites is chiefly characteristic of the Lower 

Triassic Columbites zone of Idaho and Albania, but 

some retarded species are found in the Middle Triassic 

of Nevada.

Family TROPITIDAE

Mojsisovics 41 has assumed that the Tropitidae 

developed out of Gastrioceras of the Carboniferous, in 

spite of the enormous gap that existed from the Permian to the Upper Triassic. It was supposed that 

Paraceltites of the Permian and Isculites of the Middle 

Triassic partly filled the gap, but the former genus is 

now assigned to Xenodiscidae and the latter to 

Haloritidae* The writer 42 has described several 

species of Columbites from the Lower Triassic of Idaho, 

and in the second paper listed he has named several 

species of the then new genus Tropiyastrites from the 

Middle Triassic of Nevada.

Arthaber 43 recognized Columbites as a common 

member of the Lower Triassic fauna of 'Albania, and 

along with it he described the genus Protropites, which 

in his opinion has even greater right than Columbites 

to be considered the radicle of the Tropitidae. It is 

certainly true that the late larval stages of Tropites 

subbullatus, Paratropites sellai, and Discotropites sandlingensis, as figured by the writer 44 in 1905, six years

39 Uyatt, Alphcus, and Smith, J. P., The Triassio cephalopod genera of America: 

U. S. Geol. Survey Prof. Paper 40, p. 51, 1005. Smith, J. P., The Middle Triassic 

marine invertebrate faunas of North America: U. S. Oeol. Survey Prof. Paper 

83, pp. 30, 37, 1914.

 "> Arthaber, O. von, op. cit. (Die Trias von Albanien), pp. 260-204.

11 Mojsisovics, E. von, Die Cephalopoden d<?r Mallstfittcr .Kalko: K.-k. geol. 

.Heiehsanstalt Wien Abh., Band 6, Hiilfte 2, p. 7, 1893.

» Hyatt, Alpheus, and Smith, J. P., op. cit. (Prof. Paper 40), p. 50. Smith, J. P., 

op. cit. (Prof. Paper 83), p. 36.

« Arthaber, O. von, op. cit. (Die Trias von Albanien), pp. 179, 260.

14 ILyatt, Alpheus, and Smith, J. P., op. cit. (Paratropites seltai, pi. 31, figs. 14-33; 

Discotropites sundlingensis, pi. 30, figs. 1-9; Tropiles snbbullatus, pi. 79, figs. 1-6).
38 LOWER TRIASSIC AMMONOIDS OF NORTH AMERICA

before the publication of Arthaber's work, resemble 

greatly the adults of Protropites. The writer accepts 

Protropites as an ancestral form but considers it a 

possible link between Columbites and Tropigastrites.

In the development of several genera of Tropitidae, 

as studied by the writer, the "Columbites," "Protropites," and "Tropigastrites" stages are so telescoped 

by unequal acceleration that it is impossible to segregate them. Reversionary or retarded groups, such 

as Margarites, Sty rites, Sibyllites, and Tropiceltites, 

give strong reminiscences of the Lower and Middle 

Triassic ancestors but can not be correlated definitely 

with them. But all Tropitidae, and indeed all Tropitoidea, show in the larval stages perfect recapitulations of Gastrioceras, which become gradually smaller 

as we come up the geologic column. Therefore there 

is more complete agreement as to the genealogy of this 

group than as to that of any other phylum of ammonoids.

Family HAIORITIDAE

By nearly all writers the Haloritidae have been regarded as a branch of the Tropitidae and as derivatives 

of the same stock of Gastrioceratea. But the writer 

is of the opinion that although the Haloritidae sprang 

from Gastrioceras, it was not from the main line, or 

of the group of G. listeri, but from the group of G. 

globulosum and that the divergence began even in 

the "Coal Measures."

Timorites Haniel, from the Permian of Timor, shows 

the family already differentiated then, as does Ploffmannia Gemmellaro, of the Sicilian Permian.

Juveniles Smith shows the first step upward from 

Gastrioceras in the Pseudosageceras multilobatum subzone of the Lower Triassic of Idaho. The next step is 

shown by Thermalites Smith, in the same beds, in which 

the septa have become slightly serrated. Both these 

genera are distinctly gastrioceran until nearly grown. 

The next sign of progress is seen in Isculites Alojsisovics, 

in the Columbites zone, in which the septa have become 

slightly ammonitic.

It was once generally thought that the needed Lower 

Triassic ancestral link was supplied by Sibirites or 

Anasibirites. 45 But this group, at least the Anasibirites part of it, is now definitely placed in the Meekoceratidae. However, Isculites gives a good connection with the varied Haloritidae of the Karnic and 

Noric horizons.

In the Upper Triassic Juvavites and Sagenites are the 

most abundant groups, followed closely by Plaloritefi 

and its kindred. The first two of these show in their 

development distinct gastrioceran stages, followed by 

suggestions of Isculites.

In the Upper Karnic there are also numerous retrograde or retarded genera, such as Leconteiceras Smith,

45 Arthabcr, G. von, op. cit. (Die Trias von Albanien), p. 254. Arthaber accepts 

Sibirites as a member of the Meekoceratidae but places Anasibirites (Pseudosibirites 

Arthaber) under the Acrochordiceratidao. 

Homerites Mojsisovics, and Metasibirites Mojsisovics, 

which have stopped almost in the Gastrioceras stage 

but in their sculpture still show remnants of the characters of their more progressive kinsmen. Metasibirites was described by Mojsisovics 46 as a subgenus 

under Sibirites, and the assignment of Sibirites to the 

Haloritidae has caused confusion. In its development 

Metasibirites is clearly a member of the Gastrioceratea, 

whereas Sibirites almost certainly belongs to Ceratitoidea.

The development of the retrograde genera of the 

Haloritidae listed above has been fully described by 

the writer. 47

Superfamily ARCESTOIDEA

The group here called the Arcestoidea has been 

called by Arthaber 48 Agathiceratea, a name which is 

hardly applicable as a general term for the phylum, as 

only the Arcestidae s. s., and the Cladiscitidae could 

have come from Agathiceras.

The first of the Arcestoidea to deploy from the parent 

Gastrioceras were the Cyclolobidae, which seem to 

have branched out from the group of Gastrioceras 

globulosum in the "Coal Measures," as Paralegoceras, 

Shumardites, and Marathonites. These forms have been 

fully described by the writer,49 by Bose,50 and by 

Haniel. 51

All these true Cyclolobidea (excluding of course 

Monophyllites and its kindred) have apparently 

developed out of Shumardites, early reaching the 

transitional genus Marathonites, which is widespread 

in the lower Permian of the Ural region, Sicily, Texas, 

and Timor, and going on into Perrinites, Waagenoceras, 

and Cyclolobus. All these are now fairly common and 

well-known genera, and the young stages of most of 

them have been studied and described in published 

works by the writer.

It is not known that the Cyclolobidae continued into 

the Triassic, but Arthaber 52 shows that Joannites and 

its kin probably form such a continuation.

Family ARCESTIDAE

The true Arcestidae appear to have branched off 

from Adrianites Gemmellaro, of the lower Permian, and 

continued into the Lower Triassic in the form of 

Prosphingites Mojsisovics, which, although the earli46 Mojsisovics, E. von, Beitriige zur Kenntniss der obertriadischen Cephalopoden 

Faunen des Himalaya: K. Akad. Wiss. Wien Denkschr., Band 63, p. 616, 1896.

" Hyatt, Alpheus, and Smith, .T. P., op. cit. (Prof. Paper 40), p. 35. Smith, jr. P., 

Upper Triassic marine invertebrate faunas of North America: U. S. Geol. Survey 

Prof. Paper 141, pp. 21-25, 1927.

*s Arthaber, G. von, op. cit. (Die Trias von Albanien), p. 178.

49 Smith, J. P., The Carboniferous ammonoids of America: U. S. Geol. Survey 

Mon. 42, pp. 99, 134, 1903; Permian ammonoids of Timor: 2° Nederlandsche TimorExpeditie onder Leiding van Dr. H. G. Jonkert: Jaarboek van het Mijnwezcn in 

Ned. Indie', 1926, Verh. 1, pp. 31, 46, 1927.

60 Bose, Emil, The Permo-Carboniferous ammonoids of the Glass Mountains, 

western Texas: Texas Univ. Bull. 1762, pp. 99, 133, 1917.

51 Haniel, C. A., Die Cephalopoden der Dyas von Timor: Palaontologie von 

Timor, Lief. 3, Abb. 6, pp. 58-65, 1915.

52 Arthaber, G. von, Die Trias von Bithynien (Anatolien): Beitr. Palaontologie 

Oesterr.-Ungarns u. des Orients, Band 27, p. 164, 1914.
XENODISCIDAE 39

est known member, may not be the true radicle. 

Parapopanoceras Hang is another Lower Triassic genus 

of this phylum, but typical Arcestidae are unknown 

before the Middle Triassic. The stock persists until 

the end of the Triassic, still in its monotonous uniformity but with great wealth of species.

The writer has studied the young of Parapopanoceras and of numerous species of Arcestes, and all show 

striking similarity to round Gastrioceras and to typical 

Adrianites.

Family PTYCHITIDAE

The Ptychitidae have been most variously treated 

of all the so-called families of Triassic ammonoids and 

have been an extremely unsatisfactory mixture of 

heterogeneous elements. Mojsisovics 53 originally included, the group under the superfamily Pinacoceratidae. Arthaber 54 puts the Ptychitidae under the 

phylum Tornoceratea and still includes the Gymnitinae in the family. He would thus include a large 

portion of Frech's Xenodiscidae, also Gymnites and 

its kindred and the early Phylloceratidae. The 

phylum Tornoceratea is not now generally accepted; 

few of the genera under it, if any, could have come 

from Tornoceras directly, for it is too far back to be 

accepted as a definite radicle.

In the sixth edition of Zittel's work 55 the Carnitinae 

and Gymnitinae are still included under Ptychibidae, 

although the other incongruous elements are left out.

As here restricted the Ptychitidae include Nannites 

Mojsisovics, Paranannites Hyatt and Smith, Owenites 

Hyatt and Smith, Proptychites Waagen, and Ptychites 

Mojsisovics. All these forms are very similar in the 

young stages, recapitulating perfectly Gastrioceras, 

with its broad roundish whorls and strong periodic 

constrictions. The septa change gradually from the 

goniatitic Nannites, through the ceratitic Paranannites 

and Owenites, to the ammonitic Ptychites.

The writer would also class under Ptychitidae those 

forms described by Hauer 56 from the Muschelkalk of 

Bosnia as Proteusites and also as the group of Ceratites 

decrescens. These species, of which the young stages 

have not been described, are clearly Gastrioceratea 

and apparently more nearly related to Ptychites than 

to the Haloritidae. The late larval stage of Ptychites 

seebachi Mojsisovics greatly resembles Proteusites, but 

this does not mean very much, for the two are approximately contemporaneous, and it is not known that 

Proteusites antedates Ptychites.

83 Mojsisovics, E. von, Die Cephalopoden der Mediterranen Triasprovinz: K.-k. 

geol. Reichsanstnlt "VVien Abh.. Band 10, p. 244, 1882.

41 Artlinber, O. von, 'Die Trias von Albanieu: Beitr. Palfiontologie Oesterr.- 

Ungarns u. des Orients, Band 24, p. 177, 1911.

» Zittel, K. A. von, Orundziige der Palaeontologie, 6th ed. (edited by Ferdinand 

Broili), p. 560. 1924.

*> Hnucr, F. von, Beitrttge zur Kenntniss der Cephalopoden aus der Trias von 

Bosnion: K. Aknd. Wiss. AVien Denkschr., Band 59, p. 267, 1892.

SYSTEMATIC DESCRIPTIONS

Clan GEPHYROCERATEA 

Superfamily PROLECANITOIDEA

Form evolute or involute, laterally compressed; 

body chamber usually short but long in some genera; 

surface commonly ornamented with ribs, in some forms 

with knots or spines. Septa goniatitic in some primitive forms, ceratitic in most, and ammonitic in a few 

highly specialized genera.

The Prolecanitoidea form a remarkably homogeneous group, but it is so various that, although the 

relationship is plain, there is great difficulty in giving 

a diagnosis that will include all the families and genera. 

Frech 67 used the name Ceratitoidea for the group, but 

he included also the Ptychitidae and the Tropitidae in 

it. With the exclusion of these foreign elements, however, the group, as he established it, appears to be 

phylogenetically homogeneous, although the members 

may differ as widely from one another in appearance as 

they do from members of other suborders. The 

Hungaritidae, Meekoceratidae, and Gymnitidae had 

been previously classed as Leiostraca and the. Ceratitidae as Trachyostraca, an arbitrary separation, 

based on the character of the sculpture in some forms. 

Frech showed that rough-shelled and smooth-shelled 

genera might occur in any of the families and represented only stages of development. The more primitive members of each family are smooth-shelled, 

whereas most of the highly specialized members 

become rough-shelled.

The young stages of all the Prolecanitoidea, so far 

as known, are evolute, discoidal, little embracing, 

resembling Paralecanites Diener, which may be considered the radicle of the group and the connecting 

link with the true Prolecanitidae of the Carboniferous. 

Some few of the primitive types persist until the 

Triassic, such as Lecanites, which lived on until the 

Upper Triassic, and the retrograde genera revert to 

this type.

Under the Prolecanitoidea are included the Xenodiscidae, the Meekoceratidae, the Hungaritidae, the 

Phylloceratidae, the Gymnitidae, the Ceratitidae, and 

the Trachyceratea. All these families are supposed to 

have become extinct by the end of the Triassic except 

the Phylloceratidae, which persisted until near the 

end of the Cretaceous.

Family XENODISCIDAE

Form evolute, discoidal, laterally compressed. Body 

chamber variable in length. Surface ornamented with 

lateral ribs or folds. Septa goniatitic or ceratitic.

The Xenodiscidae were formerly regarded as a 

subfamily under the Tropitidae purely on account of

" Frech, Fritz, Die Dyas: Lethaea geognostica, Teil 1, Das Palaeozoicum, Band 

2, Liel. 3, p. 478, 1901.
40 LOWER TRIASSIC AMMONOIDS OF NORTH AMERICA

their lateral ribs and supposed long body chamber. 

But no member of the Tropitidae has young stages 

that in any way resemble Xenodiscus, and the characters on which that reference was based occur in 

other groups. The Xenodiscidae can not have descended from the Glyphioceratidae, the group in which 

the ancestors of Tropites are to be sought, but from 

some member of the Prolecanitidae. The kinship of 

this group with the primitive members of the Ceratitidae, Hungaritidae, and Meekoceratidae is evident 

and acknowledged by most students of ammonoids. 

Frech probably had this family in mind when he included the Tropitidae in the suborder Ceratitoidea, 

although the true Tropitidae can not have any kinship 

with it.

The Xenodiscidae are represented in the Permian 

of Asia by Lecanites, Xenodiscus, and Xenaspis; 

in the Permian of the Mediterranean region by 

Paraceltites and Paralecanites; in the Permian of 

America by Paraceltites and Paralecanites; in the Lower 

Triassic of Asia by Lecanites, Flemingites, Xenodiscus, 

Ophiceras, and Xenaspis; and in the Lower Triassic 

of America and the Mediterranean by the same 

genera, except that Flemingites is not yet known in 

the faunas of the ancient Mediterranean. Xenodiscus, 

at least, and probably Flemingites are common in 

the Arctic Lower Triassic.

It is now pretty generally accepted that the Xenodiscidae include the ancestors of the Meekoceratidae and 

Ceratitidae and thus, secondarily, of the Gymnitidae 

and Phylloceratidae.

Genus LECANITES Mojsisovics

1882. Lecanites. Mojsisovics, Die Cephalopoden der Mediterranen Triasprovinz: K.-k. geol. Reichsanstalt Wien 

Abh., Band 10, p. 199.

1895. Lecanites. Waagen, Fossils from the Ceratite formation: 

India Geol. Survey Mem., Palaeontologia Indica, 

12th ser., Salt Range fossils, vol. 2, p. 275.

1896. Lecanites. Diener, Cephalopoda of the Lower Trias:

India Geol. Survey Mem., Palaeontologia Indica,

15th ser., Himalayan fossils, vol. 2, pt. 1, p. 146. 

1902. Lecanites. Frech, Die Dyas: Lethaea geognostica, Teil

1, Das Palaeozoicum, Band 2, Lief. 4, p. 634. 

1905. Lecaniles. Hyatt and Smith, The Triassic cephalopod

genera of America: U. S. Geol. Survey Prof. Paper

40, p. 137. 

1908. Lecanites. Arthaber, Ueber die Entdeckung von Undertrias in Albanien: Geol. Gesell. Wien Mitt., Band 1,

p. 268.' 

1911. Lecanites. Arthaber, Die Trias von Albanien: Beitr.

Palaontologie Oesterr.-Ungarns u. des Orients, vol.

24, p. 237.

1914. Lecanites. Smith, Middle Triassic marine invertebrate 

faunas of North America: U. S. Geol. Survey Prof. 

Paper 83, p. 65.

1915. Proavites. Diener, Cephalopoda Triadica; Fossilium 

Catalogus; I, Animaiia, pt. 8, p. 228.

Not 1896. Proavites. Arthaber, Die Cephalopoden Fauna der 

Reiflinger Kalke: Beitr. Palaontologie Oesterr.-Ungarns u. des Orients, Band 10, p. 104.

Type: "Ceratites" glaucus Muenster. 58 

Evolute, discoidal; little-embracing whorls, laterally flattened, and higher than wide. Wide umbilicus, 

whorls increasing slowly in height. Abdomen narrow, either flattened or rounded. Surface smooth or 

sculptured with radial folds. Body chamber short, 

not more than three-quarters of a revolution in length. 

Septa goniafcitic, lobes and saddles all entire. The 

external lobe is invariably divided by a siphonal saddle. 

There are two lateral lobes present in all species and 

commonly a small auxiliary.

Lecanites, even at maturity, has a strong resemblance to Gephyroceras, as described and limited by 

Holzapfel. 59 Lecanites vogdesi closely resembles G. 

uchtense Holzapfel 60 of the upper Devonian.of Russia. 

Gephyroceras is probably the ultimate radicle of 

Lecanites and thus of the entire group of Ceratitoidea, 

but the intermediate or secondary radicle was prob- 

 ably Prolecanites of the Carboniferous. Nomismocerasis thought by some to have been the secondary radicle 

but is too little known and is very improbable. It is 

doubtful whether the Middle Triassic species of 

Lecanites are congeneric with the Lower Triassic forms 

assigned to this genus. The former may be fixed or 

even retarded species, whereas the latter are progressive, radicle types. Diener 61 places the species of 

Lower Triassic age, previously assigned to Lecanites, 

under the genus Proavites Arthaber. 62 But this does 

not make the case any better, for Proavites is also 

probably only a degenerate descendant of the Meekoceratidae and has little resemblance to the t37pical 

Lecanites of the Lower Triassic. If a change in name 

must be made it will be a great deal safer to fall back 

upon the name Paralecanites Diener, even though it is 

not well established. The writer proposes to do this 

and to treat Paralecanites as a subgenus, to include the 

simple, progressive ancestral types of the Lower 

Triassic.

Subgenus PARALECANITES Diener

1897. Paralecanites. Diener, K. Akad. Wiss. Wien Sitzungsber.,.

Band 106, p. 66. 

1901. Paraceltites (part). Frech, Lethaea geognostica, Teil 1,

Das Palaeozoicum, Band 2, Lief. 3, p. 552. 

1901. Paralecanites. Diener, Ueber die systematische Stellungder Ammoniten des siidalpinen Bellerophonkalkes:.

Centralbl. Mineralogie, 1901, No. 14, p. 436. 

1905. Paralecanites. Hyatt and Smith, The Triassic cephalopod

genera of America: U. S. Geol. Survey Prof. Paper 40,.

p. 136.

w Muenster, G. Graf zu, Ueber das Kalkmergel-Lager von St. Cassian in Tyrol: 

Neues Jahrb., 1834, p. 11, pi. 1, fig. 1; also in Mojsisovics, E. von, Die Cephalopoden 

der Mediterranen Triasprovinz: K.-k. geol. Reichsanstalt Wien Abh., Band 10,. 

p. 200; pi. 30, figs. 1-6; pi. 53, fig. 14, 1882.

5'Holzapfel, E., Die Cephalopoden des Domanik im siidlichen Timan: Com., 

geol. [St. Petersbourg] M6m., vol. 12, No. 3, p. 27, 1899.

so Idem, pi. 5, figs. 4-7.

61 Diener, Carl, Fossilium Catalogus; I, Animaiia, pt. 8, Cephalopoda Triadica,. 

p. 228, 1915.

62 Arthaber, G. von, Die Cephalopoden Fauna der Reiflinger Kalke: Beitr.. 

Palaontologie Oesterr.-Ungarns u. des Orients, Band 10, Heft 1, p. 104, 1896.
XENODISCIDAE 41

Type: Paralecanites sextensis Diener.

This siibgenus is characterized by its evolute, littleembracing, low whorls, wide umbilicus, almost total 

absence of sculpture, and goniatitic septa. The 

ventral lobe is divided, and there are two laterals, with 

no auxiliary lobe. The internal lobes are unknown on 

the type but presumably would consist of an antisiphonal lobe flanked by an internal lateral, as this is 

the arrangement in. all primitive ammonites of this 

group.

These characters agree in all essentials with the 

genus Lecanites Mojsisovics, except in the absence of 

the auxiliary lobe, and Diener regards Paralecanites as 

the stock from which sprang Lecanites and the Meekoceratidae.

Frech °3 regards Paralecanites as synonymous with 

Paraceltites Gemmellaro, disregarding the sculpture 

and the shape of the external lobe in Paraceltites. 

The latter character is probably not fundamental, 

for Paraceltites elegans Girty and P. multicostatus 

Bose both show a slight division of the external lobe. 

The length, of the body chamber is also doubtful in all 

these forms.

B'orizon and locality: Paralecanites was first known 

from the Permian of the Alps, but species agreeing in all essentials with the generic characters of 

the type have been found in the Lower Triassic 

Meekoceras zone of southeastern Idaho, associated with 

a typical Lower Triassic fauna. Also most of the socalled Lecanites described by Waagen from the Salt 

Range of India and by Arthaber from the Columbites 

/one of Albania would fall under the subgenus Paralecanites.

Lecanites (Paralecanites) arnoldi Hyatt and Smith

Plate 28, Figures S-10; Plate 39, Figures 9-12; Plate 59, 

Figures S-10; Plate 64, Figures 1-16

1905. Paralecaniles arnoldi. Hyatt and Smith, The Triassic 

cephalopod genera of America: U. S. Geol. Survey 

Prof. Paper 40, p. 136, pi. 64, figs. 1-16; pi. 77, figs. 

9-12.

Form evolute; whorls subquadratic in cross section, 

slightly higher than wide, low and increasing very 

slowly in height, little embracing, and scarcely indented by the inner whorls. The sides and venter are 

flattened, the umbilical shoulders are rounded, and the 

ventral shoulders sub angular, this character being 

more pronounced in the late adolescent stages than at 

maturity.

The umbilicus is very wide and shallow, being nearly 

half the entire diameter of the shell.

The septa are goniatitic, consisting of a divided 

ventral lobe, a large first lateral lobe, and a small 

second lateral just above the umbilical shoulder.

03 Frcch, Fritz, Die Dyas: Lethaea geognosticn, Teil 1, Das Palaeozoicum, Band 

2, Liof. 3, p. 478, 1001.

There is no auxiliary lobe, but the internal lateral is 

visible, on account of the evolution of the shell, 

outside the umbilical suture. The antisiphonal lobe 

is long and divided.

The septa are exactly like those of Lecanites except 

in the lack of an auxiliary lobe, there being only 8 

lobes in Paralecanites and 10 in Lecanites s. s.

The surface at maturity is nearly smooth, ornamented only with nearly obsolete low radial folds. 

In early youth, up to a diameter of about 5 millimeters, the folds are much stronger and the cast is 

marked with distinct constrictions that run from the 

umbilicus across the venter. At this stage, also, the 

cross section of the whorl is rounded instead of subquadratic and the ventral lobe is undivided, the division taking place at a diameter of a little more than 

5 millimeters.

This early adolescent stage of Paralecanites is like 

that of Xenodiscus, as described and figured in this 

paper, and the mature form is very like the larval 

stages of Meekoceras. This resemblance points to 

Paralecanites as the radicle of the Meekoceratidae, 

a family which must have developed in the Permian, 

for highly specialized representatives are known at 

the very bottom of the Triassic and, indeed, in a 

formation considered by some authorities to be upper 

Permian. Paralecanites arnoldi can not therefore be 

the radicle but is merely a little-modified survival of 

the ancestral form.

It is highly probable that Paralecanites, or some 

similar form, was the family radicle, not only of the 

Meekoceratidae but also of all the true Prolecanitoidea. 

It is also probable that this form came from the earlier 

Paleozoic genus Prolecanites, through the Permian 

Paraceltites. This relationship would make the Prolecanitoidea descendants of the direct line of Prolecanitidae, whereas Medlicottia and its allies are descended 

from a side branch of the same stock.

Horizon and locality: Meekoceras zone, Lower 

Triassic, Wood Canyon, Aspen Ridge, 9 miles east of 

Soda Springs, Idaho, associated with Meekoceras 

gracilitatis, M. mushbachanum, Pseudosayeceras multilobatum, Hedenstroemia kossmati, Cordillerites angulatus, Paranannites aspenensis, Flemingites russelli, 

and many other forms characteristic of the Lower 

Triassic.

Lecanites (Paralecanites) knechti Hyatt and Smith

Plate 9, Figures 11-16; Plate 28, Figures 1-7

1905. Lecanites knechli. Hyatt and Smith, The Triassic 

cephalopod genera of America: U. S. Geol. Survey 

Prof. Paper 40, p. 138, pi. 9, figs. 11-16.

Evolute, discoidal, laterally compressed; wide, 

shallow umbilicus; sides flattened, umbilical shoulders 

broadly rounded; venter rather broad and rounded, 

so that there are no distinct abdominal shoulders.
42 LOWER TRIASSIC AMMONOIDS OF NORTH AMERICA

Whorls increasing slowly in height and little embracing, concealing only about one-third of the inner volution and being indented to only one-sixth of the height 

by it. The width of the whorl is nearly three-fourths 

of the height.

Surface smooth, only casts that show no ribs nor 

folds being known.

Septa goniatitic, external lobe divided into two 

narrow short branches, which fall on the abdominal 

shoulders; first lateral longer and much broader; 

second lateral nearly as broad as the first but much 

shorter. Auxiliary lobe lacking entirely. Internal 

septa consisting of a long antisiphonal lobe and a 

short shallow lateral, just inside the umbilical suture. 

The form and septa are exactly like those of the young 

of Flemingites aplanatus, but the lobes of Flemingites 

become serrated at a very early adolescent stage, 

whereas those of Lecanites remain goniatitic.

Lecanites knechti belongs to the group of L. gangeticus 

De Koninck, characterized by the possession of 

rounded instead of angular and flattened venters, and 

in shape it is most nearly related to the Salt Range 

species of India, but differs in lacking the auxiliary 

lobe and in not having any varices on the shell.

L. knechti also resembles L. glaucus Muenster, the 

type of the genus, but is somewhat more evolute than 

that species and lacks the auxiliary, which is present 

on the type species.

There are in the Lower Triassic of America several 

species of Xenodiscus that agree closely with this 

species of Lecanites, except that they possess ceratitic 

lobes and thus are more highly developed, either out 

of it or some similar member of the same genus. They 

all go through a Lecanites stage.

Relative dimensions of the type of Lecanites knechti

Diameter.______________________________ 100

Height of last whorl_--_-_-----_--_-_----_ 35

Height of last whorl from preceding. _______ 30

Width of last whorl_______________-_l_-__ 26

Width of umbilicus----.------------------ 39

Involution _______--____--_-___-_---_-_-_ 5

Actual diameter-of .the. type specimen, 30 millimeters.

Horizon and locality: Lecanites knechti was found by 

J. P. Smith in the Lower Triassic Owenites subzone of 

the Meekoceras zone of the Inyo Range in Union Wash, 

about IK miles east of Union Spring, about 15 miles 

southeast of Independence, Inyo County, Calif. It 

was associated with Meekoceras gracilitatis White, M. 

mushbachanum White, and many other characteristic 

species of the Lower Triassic.

It was also found in the Meekoceras zone, at Wood 

Canyon, Aspen Ridge, Idaho, 9 miles east of Soda 

Springs, in approximately the same fauna as in California but lower in the Meekoceras zone.

Genus XENODISCUS Waagen

1879. Xenodiscus (part). Waagen, Prodiidus limestone fossils: 

India Geol. Survey Mem., Palaeontologia Indica, 

13th ser., Salt Range fossils, vol. 1, p. 32.

1886. Xenodiscus. Mojsisovics, Arktische Triasfaunen: Acad. 

imp. sci. [St.-Petersbourg] Me"m., 7th ser., vol. 33, 

No. 6, p. 74.

1895. Xenodiscus. Waagen, Fossils from the Ceratite formation: India Geol. Survey Mem., Palaeontologia Indica, 

13th ser., Salt Range fossils, vol. 2, p. 161.

1895. Xenodiscus. Diener, Cephalopoda of the Muschelkalk: 

India Geol. Survey Mem., Palaeontologia Indica, 

15th ser., Himalayan fossils, vol. 2, pt. 2, p. 110.

1897. Danubites. Diener, Cephalopoda of the Lower Trias: 

India Geol. Survey Mem., Palaeontologia Indica, 

15th ser., Himalayan fossils, vol. 2, pt. 1, p. 24.

1900. Wyomingites. Hyatt, Cephalopods, in Zittel, K. A. von, 

Textbook of palaeontology (translated by C. R. Eastman), p. 556.

1902. Xenodiscus. Frech, Lethaea geognostica, Teil 1, Das 

Palaeozoicum, Band 2, Lief. 4, p. 634a.

1903. Proceratites. Kittl, Die Cephalopoden der oberen Werfener Schichten von Mud in Dalmatien: K.-k. geo) 

Reichsanstalt Wien Abh., Band 20, Heft 1, p. 28.

1909. Xenodiscus. Diener and Krafft, Lower Triassic Cephalopoda from Spiti, Malla Johar, and Byans: India Geol. 

Survey Mem., Palaeontologia Indica, 15th ser., vol. 6, 

Mem. 1, p. 83.

1911. Xenodiscus. Arthaber, Die Trias von Albanien: Beitr. 

Paliiontologie Oesterr.-Ungarns u. des Orients, Band 

24, p. 227.

1913. Xenodiscus. Diener, Triassic faunae of Kashmir: India 

Geol. Survey Mem., Palaeontologia Indica, new ser., 

vol. 5, Mem. 1, p. 2.

1914. Xenodiscus. Smith, Middle Triassic marine invertebrate

faunas of North America: U. S. Geol. Survey Prof.

Paper 83, p. 55. 

1922. Xenodiscus. Welter, Die Ammoniten der Unteren Trias

von Timor: Palaeontologie von Timor, Lief. 11, Abh.

19, p. 106. 

1927. Xenodiscus. Yehara, The Lower Triassic cephalopod

and bivalve fauna of Shikoku: Japanese Jour. Geology

and Geography, vol. 5, No. 4, p. 163. 

1927. Xenodiscus. Smith, Permian ammonoids of Timor:

2C Nederlandsche Timor-Expeditie onder Leiding van

Dr. H. G. Jonkert: Jaarboek van het Mijnwezen in

Ned.-Indie, 1926, Verh. 1, p. 28. 

1929. Xenodiscus. Mathews, The Lower Triassic cephalopod

fauna of the Fort Douglas area, Utah: Walker Mus.

Mem., vol. 1, No. 1.

Type: Xenodiscus plicatus.W&&ge,n..6i

Evolute, discoidal, little embracing, increasing 

slowly in height, widely umbilicate, laterally compressed. Body chamber said to be long but in reality 

not so. Lateral sculpture strong, even on inner 

whorls, consisting of strong folds running from the 

umbilicus up the sides. Venter abruptly rounded. 

Septa ceratitic, lobes and saddles short.

When this genus was first named, Waagen placed 

it in the Leiostraca, in close relationship with Gymnites.

64 Waagen, W., Productus limestone fossils: India Geol. Survey Mem., Palaeontologia Indica, 13th ser., Salt Range fossils, vol. 1, p. 34, pi. 2, figs. 1, la, If, 1879.
XENODISCIDAE 43

Further study, howler, convinced him that this would 

apply only to one species classed under Xenodiscus, 

which, he afterward separated under the name Xenaspis 

carbonaria Waagen. The type, Xenodiscus plicatus, 

was then classed under the Celtitinae, subfamily of 

the Tropitidae. In the meantime Mojsisovics,65 under 

the supposition that "Ceratites" carbonarius was the 

type of Xenodiscus, classed X. plicatus under the group 

of Ceratites obsoleti, which he afterward designated 

by the subgeneric title Danubites. The Middle Triassic 

species classed, by Diener under Xenodiscus belong to 

Xenaspis. Thus only the type, Xenodiscus z>licatus 

Waagen, remained under this genus. It became therefore extremely easy to determine the generic characters. 

It is not so easy, however, to determine the systematic 

position. Waagen considered it to be intermediate 

between Paraceltites and Celtites, but this view has 

nothing to sustain it. The possession of a long body 

chamber alone is not sufficient to place this genus in 

the Tropitidae, for the writer has demonstrated that 

members both of the Ptychitidae and of the Ceratitidae may have body chambers at least a revolution 

long. It is also very doubtful whether the type of 

Xenodiscus possesses a body chamber as long as a full 

revolution.

Frech °° classes Xenodiscus, Xenaspis, Hungarites, 

and Otoceras together as the subfamily Xenodiscinae 

under the Ceratitoidea. By leaving out Hungarites 

and Otoceras this is a proper classification, for Xenodiscus and Xenaspis are certainly related to the general 

group of ceratitic ammonites, either as ancestors or as 

survivals of ancestral types, whereas Hungarites and 

Otoceras are more specialized and have no right to be 

classed, in the ancestral group. It is highly probable 

that the Meekoceratidae, the Hungaritidae, and the 

Ceratitidae all sprang from a common stock the 

Xenodiscinae and that this group took its origin 

from some primitive form like Paralecanites. But 

this differentiation must have taken place before the 

upper Permian, for there we have Xenodiscus, Xenaspis, 

Paraceltites, Paralecanites, Otoceras, and Hungarites, 

all flourishing simultaneously.

The genus Xenodiscus has been completely revised, 

restricted, and expanded by Krafft and Diener.67 

These authors include in Xenodiscus most of the Lower 

Triassic species formerly ascribed to Danubites, nearly 

all of Gyronites, many of Prionolobus, and some of the 

so-called Celtites. This arrangement expands Xenodiscus far beyond what Waagen intended the genus to 

include and will probably necessitate subdividing it 

into several subgenera. This has already been partly

«» Mojsisovlcs, E. von, Arktische Triasfauncn: Acad. imp. sci. St.-P6tcrsbourg 

M6in.,-7tb sor., vol. 33, No. 6, p. 20, 1886.

«» Frccli, Fritz, Dio Dyas: Lothaea gcognostica, Teil 1, Das Palaeozoicum, Band 

2, Lief. 3, p. 478, 1001.

07 Kratt't, A. von, and Diener, Carl, Lower Triassic Cephalopoda from Spiti, 

Malta Jolmr, and Byans: India Qeol. Survey Mom., Palaeontologia Indica, 15th 

ser., vol. C, No. 1, pp. 83 et seq., 1909.

67664 32 4

done, in the recognition of Paratirolites Stoyanow and 

Xenaspis Waagen as subgenera, and of the unnamed 

group of Xenodiscus nivalis as nearly related to 

Paratirolites. Among these different forms may be 

found the ancestors of Ophiceras, Flemingites, Meekoceras, Anasibirites, and even of the multiform group 

of Ceratites itself.

The following species of Xenodiscus are recognized 

in the Lower Triassic of America: Group of Xenodiscus 

plicatus Waagen, Xenodiscus s. s.: X. cordiileranus 

Smith, X. gilberti Smith, X. intermontanus Smith, X. 

rotuia Waagen, X. toulai Smith, X. waageni Hyatt and 

Smith, X. whiteanus Waagen; group of Xenodiscus 

nivalis: X. nivalis Diener; group of Xenodiscus carbonarius Waagen, subgenus Xenaspis Waagen: X. marcoui 

Hyatt and Smith.

Xenodiscus cordilleranus Smith, n. sp.

Plate 24, Figures 21-29

Shell small, evolute, discoidal, widely umbilicate, 

somewhat compressed laterally, little embracing. 

Cross section of whorl subquadratic, with abruptly 

rounded umbilical and ventral shoulders. Ornamented 

with fine, strong transverse ribs that cross the venter 

without interruption. These ribs are bundled somewhat after the manner of those on Cuccoceras, suggesting kinship and possible ancestry of that Middle 

Triassic genus. The form is more like Ophiceras, but 

the absence of the spiral striae does not permit a reference to this genus. The septa are ceratitic, with three 

external serrated lobes, the auxiliary not being developed.

The height of the last whorl is less than one-third of 

the diameter of the shell. The width is two-thirds of 

the height; the width of the umbilicus is three-sevenths 

of the diameter of the shell. The outer whorl embraces two-fifths of the inner and is indented to onefourth of the height.

Xenodiscus cordilleranus has some resemblance to X. 

intermontanus but differing in its squarer whorl and 

much stronger sculpture.

Horizon and locality: Rather rare in the Lower 

Triassic Meekoceras zone of southeastern Idaho, at 

locality 3, head of Wood Canyon, Aspen Mountains, 9 

miles east of Soda Springs, associated with Meekoceras 

gracilitatis, M. mushbachanum, Flemingites russelli, 

Hedenstroemia kossmati, Cordillerites angulatus, Lanceolites compactus, Ussuria waageni, Aspenites acutus, 

Pseudosageceras multilobatum, and other forms.

Xenodiscus gilberti Smith, n. sp.

Plate 24, Figures 1-9

Shell small, discoidal, laterally compressed, moderately umbilicate, with gently curving sides and narrow, 

slightly flattened venter. Surface with very fine but 

distinct radial ribs that curve forward on the flanks.
44 LOWER TRIASSIC AMMONOIDS OF NORTH AMERICA

Septa ceratitic, with three external rounded saddles 

and' three broad serrated lobes. The auxiliary (or 

fourth lobe) is not developed. The height of the last 

whorl is two-fifths of the diameter of the shell, and the 

width is slightly more than half the height. The width 

of the umbilicus is about one-third of the diameter of 

the shell. The outer whorl embraces two-fifths of the 

inner and is indented by it to one-fifth of the height.

Xenodiscus gilberti is not closely related to any other 

species in the Lower Triassic of America but resembles 

X. schmidti Mojsisovics,68 of the Lower Triassic Olenek 

fauna of Siberia, differing in its somewhat stronger 

sculpture and slightly more compressed whorl. It can 

not be the young of Meekoceras sylvanum, being more 

evolute than even the young of that species and having 

stronger sculpture. It is much more compressed than 

the young of Flemingites aplanatus and lacks the spiral 

lines that appear at an early stage on all Flemingites.

Named in memory of G. K. Gilbert.

Horizon and locality: Rare in the Lower Triassic 

zone of Meekoceras, at locality 3, head of Wood Canyon, 

Aspen Mountains, 9 miles east of Soda Springs, Idaho; 

associated with Meekoceras gracilitatis, M. mushbachanum, Flemingites russelli, F. aplanatus, Hedenstroemia 

kossmati, Aspenites 'acutus, Cordillerites angulatus, 

Lanceolites compactus, Pseudosageceras multilobatum, 

and other forms.

Xenodiscus intermontanus Smith, n. sp.

Plate 24, Figures 10-20 -

Shell rather small, evolute, somewhat compressed 

laterally, widely umbilicate, with abrupt umbilical 

shoulders, convex flanks, gently rounded ventral 

shoulders, and broadly rounded venter. Surface ornamented with fine striae of growth and broad obscure 

folds. Septa ceratitic, with four external serrated 

lobes. Length of body chamber seven-eighths of a 

revolution.

The height of the last whorl is about one-third of the 

diameter of the shell; the width is two-thirds of the 

height; the width of the umbilicus is one-third of the 

diameter of the shell.

Xenodiscus intermontanus is very closely related to 

X. himalayanus Griesbach,69 of the Lower Triassic of 

India, but differs in the more robust whorls and greater 

flattening of the venter, as well as in the less individualized auxiliary lobe.

Horizon and locality: Rather common in the Lower 

Triassic Meekoceras zone of southeastern Idaho, at 

locality 3, Wood Canyon, Aspen Mountains, 9 miles 

east of Soda Springs, associated with Meekoceras gracilitatis, M. mushbachanum, Flemingites russelli, Hedenstroemia kossmati, Cordillerites angulatus, Aspenites

us Mojsisovics, E. von, Arktische Triasfaunen: Acad. imp. sci. St.-Petersbourg 

M6m., 7th ser., vol. 33, No. 6, p. 78, pi. 11, figs. 9-10, 1886.

M Diener, Carl, Cephalopoda of the Lower Trias: Palaeontologia Indica, 15tb 

ser., vol. 2, pt. 1, p. 41, pi. 14, fig. 14, 1897.

acutus, Lanceolites compactus, Ussuria waageni, Pseudosageceras multilobatum, Paranannites aspenensis, Juvenites kraffti, and other forms; also at locality 2, Slug 

Creek, Aspen Mountains, 14 miles east of Soda Springs, 

in the same horizon and fauna.

Xenodiscus nivalis Diener

Plate 56, Figures 6-12; Plate 79, Figures 1, 2

1897. Danubites nivalis. Diener, Cephalopoda of the Lower 

Trias: India Geol. Survey Mem., Palaeontologia Indica, 15th ser., Himalayan fossils, vol. 2, pt. 1, p. 51, pi. 

15, figs. 17-19.

1909. Xenodiscus nivalis. Krafft and Diener, Lower Triassic 

Cephalopoda of Spiti, Malla Johar, and Byans: India 

Geol. Survey Mem., Palaeontologia Indica, 15th ser., 

vol. 6, No. 1, p. 102, pi. 24, figs. 1, 2, 3, 5; pi. 25, fig. 5.

1922. Xenodiscus nivalis. Welter, Die Ammoniten der Unteren 

Trias von Timor: Palaeontologie von Timor, Lief. 11, 

Abh. 19, p. 107, pi. 159, figs. 19, 20.

1929. Xenodiscus hannai. Mathews, The Lower Triassic 

cephalopod fauna of the Fort Douglas area, Utah: 

Walker Mus. Mem., vol. 1, No. 1, p. 5, pi. 1, figs. 1, 4.

Shell of medium size, very evolute, discoidal, somewhat compressed laterally, with subrectangular cross 

section, little embracing, and little indented by the 

inner whorl. Ornamented with strong lateral ribs that 

become nearly obsolete on the venter, crossing it only 

as low folds. These ribs are commonly so coarse as 

to become almost knobs. Septa ceratitic, with 

rounded saddles and four external well-developed 

serrated lobes. Length of body chamber not visible 

on the American specimens but on a fine series from 

Timor are seen to be about seven-eighths of a revolution.

Xenodiscus nivalis was first described from the Lower 

Triassic Hedenstroemia beds of the Himalayas in India; 

it has since been found to be abundant at the same 

horizon, and in the same association, on Timor, in the 

East Indies. It is not nearly related to any other 

species in that region or in America, standing alone as 

a representative of a group closely allied to Paratirolites 

Stoyanow,70 of the Lower Triassic of the Caspian region 

and of Madagascar. This group has not had a subgeneric name given to it, probably because only one 

species of it has been found. Several varieties of it 

have been found in the Flemingites beds of Timor, all 

intergrading with the typical form. The American 

specimens all belong to the typical form.

Horizon an d locality: Very rare in the Owenites subzone of the Meekoceras zone of the Phelan ranch, mouth 

of Cottonwood Canyon, east side of the Ruby Range, 

Nev., about 70 miles south of Wells; associated with 

Meekoceras gracilitatis, Owenites koeneni, Inyoites oweni, 

Aspenites acutus, Lanceolites bicarinatus, Pseudosageceras multilobatum, and other forms. It occurs sparingly in the Anasibirites beds of Fort Douglas, Utah.

"° Stoyanow, A. A., On the character of the boundary of Paleozoic and Mesozoic 

near Djulfa: Kuss. k. mineral. Gesell. Verb., 2d ser.. Band 47, pt. 3, p. 75, 1909.
XENODISCIDAE 45

Xcnodiscus rotula Waagen

Plate 79, Figures 5, 6

1895. Gyronites rotula. Waagen, Fossils from the Ceratite formation: India Geol. Survey Mem., Palaeontologia 

Indica, 13th ser., Salt Range fossils, vol. 2, p. 300, pi. 

38, figs. 3-5.

1895. Gyronites radians. Waagen, op. cit., p. 302, pi. 38, 

figs. 6-8.

1909. Xenodiscus rotula. Krafft and Diener, Lower Triassic 

Cephalopoda from Spiti, Malla Johar, and Byans: 

India Geol. Survey Mem., Palaeontologia Indica, 15th 

ser., vol. 6, No. 1, p. 93, pi. 23, figs. 4, 5; pi. 27, figs. 4, 5.

1913. Xenodiscus rotula. Diener, Triassic fauna of Kashmir: 

India Geol. Survey Mem., Palaeontologia Indica, new 

ser., vol. 5, Mem. 1, p. 12, fig. 2.

1929. Ophiceras matheri. Mathews, The Lower Triassic cephalopod fauna of the Fort Douglas area, Utah: Walker 

Mus. Mem., vol. 1, No. 1, p. 4, pi. 1, figs. 38-40.

1929. Xenodiscus douglasi. Mathews, op. cit., p. 5, pi. 1, figs. 

5-7.

Not 1922. Xenodiscus rolula. Welter, Die Ammoniten der 

Unteren Trias von Timor: Palaeontologie von Timor, 

Lief. 11, Abh. 19, p. 106, pi. 159, figs. 8-10; pi. 160, 

figs. 3, 4. 'j ir,'*»'rri *- ? :

t ; > « < T.-.TUU ' ' ' ' '

Form evolute, discoid al, laterally compressed; whorls 

slowly increasing in height, embracing, and slightly 

indented by the inner volution. Sides nearly flat and 

parallel. Shoulders rounded. Umbilicus very wide 

and. shallow, being nearly one-half the diameter of the 

shell. Inner wall nearly vertical. Height of the last 

whorl less than twice its greatest thickness and nearly 

one-fourth its diameter. It is indented to one-fourth 

its height by the inner volution and conceals about 

one-third of this volution. Venter rounded and 

smooth. The shell is thin and smooth. Surface 

ornamented with many wide, nearly straight, weak 

folds which are bent forward near the outer margins 

of the side walls and cross the venter in a progressive 

manner. They are well defined near the umbilical 

shoulder on the side wall and show on all the volutions. 

Sutures ceratitic, with entire saddles and a divided 

ventral lobe.

This species was first described from the Lower 

Triassic of India; it is fairly common in the Flemingites 

beds of Timor and occurs sparingly in the Anasibirites 

beds of Utah, where it was described under the name 

Ophiceras matheri. The description given above is 

taken from Mathews's text, cited in the synonymy of 

this species.

Horizon and locality: Pinecrest formation, on the 

ridge between Parleys and Mill Canyons, central 

Wasatch Range, Utah.

Xenodiscus tarpeyi Smith, n. sp.

Plate 25, Figures 4-6

Evolute, discoidal, laterally compressed, widely umbilicate; sides flat, umbilical shoulders abruptly

rounded, venter gently rounded. The surface is 

nearly smooth, with very faint radial folds.

The septa are serrated, with rounded entire saddles 

and four serrated lobes an external, two lateral, and 

a differentiated auxiliary.

The outer whorl is two-fifths of the diameter of the 

shell, and embraces one-third of the inner; the width 

is four-fifths of the height. The width of the umbilicus 

is one-third the diameter of the shell. The length of 

the body chamber appears to be nearly or quite an 

entire revolution, which, however, appears to be not 

unprecedented in Xenodiscus and Xenaspis.

Xenodiscus tarpeyi has some resemblance to Flemingites russelli but differs in being more compressed and 

with flatter venter than that species and also in lacking 

the strong spiral lines. It differs from Flemingites 

' aplanatus in somewhat the same way but has not the 

strongly subquadratic section of that species. In fact, 

it has a general resemblance to many species of socalled Xenodiscus, Xenaspis, Ophiceras, and Flemingites of the Lower Triassic, which only goes to emphasize the near kinship of these forms and to minimize 

the importance of these artificial generic distinctions.

Named in honor of David Tarpey, who assisted in 

the collection of this fauna.

Horizon and locality: Very rare in the Lower Triassic 

Pseudosageceras multilobatum subzone of the Meekoceras zone, at locality 3, head of Wood Canyon, Aspen 

Mountains, 9 miles east of Soda Springs, southeastern 

Idaho; associated with Meekoceras gracilitatis, M. 

mushbachanum, Flemingites russelli, Hedenstroemia 

kossmati, Cordillerites angulatus, Lanceolites compactus, 

Aspenites acutus, and other forms.

It was also doubtfully identified in the Owenites 

subzone of Union Wash, Inyo Mountains, Inyo County,

Calif.

Xenodiscus toulai Smith, n. sp.

Plate 25, Figures 1-3; Plate 53, Figures 9-12

Form evolute, laterally compressed, widely umbilicate. Umbilical shoulders indistinct, sides sloping 

gradually to the rather narrowly rounded venter. 

Whorls rather high, with the greatest breadth low 

down toward the umbilical shoulders. Surface strongly 

sculptured with fine straight transverse ribs that 

become obsolete at the venter. Septa ceratitic, with 

rounded saddles and four serrated external lobes. 

Length of body chamber not visible on the few 

specimens known.

Xenodiscus toulai is closely related to "Prio7iolobus" 

falcatum Waagen, from the Salt Range of India, differing 

in the greater narrowing of the whorl toward the top 

and in the less distinct umbilical shoulders. It also 

resembles Xenodiscus himalayanus Griesbach. from 

the Lower Triassic of the Himalayas, but has finer
46 LOWER TRIASSIC AMMONOIDS OF NORTH AMERICA

sculpture and straight instead of somewhat curved 

ribs.

The species is named in honor of Franz Toula, in 

recognition of his contributions to Triassic paleontology.

Horizon and locality: Very rare in the Lower 

Triassic Meekoceras zone of locality 2, Slug Creek, 

Aspen Mountains, 14 miles east of Soda Springs, 

southeast Idaho; also one specimen in the Owenites 

subzone of the Meekoceras zone of Union Wash, Inyo 

Mountains, about 15 miles southeast of Independence, 

Inyo County, Calif. At the Idaho locality it was associated with Meekoceras gracilitatis, M. mushbachanum, Flemingites russelli, Hedenstroemia kossmati, 

Lanceolites compactus, Pseudosageceras multilobatum, 

and other forms. At the California locality it was 

associated with Meekoceras gracilitatis, M. mushbachanum, Lanceolites compactus, L. bicarinatus, Pseudosageceras multilobatum, Inyoites oweni, Owenites 

koeneni, Anasibirites desertorum, A. noetlingi, and other 

forms. The horizon in California is evidently somewhat higher than that in Idaho.

Xenodiscus waageni Hyatt and Smith

Plate 23, Figures 12-17; Plate 39, Figures 3-8

1905. Meekoceras (Prionolobus) waageni. Hyatt and Smith' 

The Triassic cephalopod genera of America: U. S' 

Geol. Survey Prof. Paper 40, p. 150, pi. 77, figs. 3-8-

Evolute, discoidal, laterally compressed. Whorls 

little embracing and little indented by the inner 

volutions. Sides flattened convex, venter narrow and 

rounded; greatest width at a point on a level with the 

top of the inner whorl. Umbilical shoulders gently 

rounded, umbilicus wide and shallow.

Surface ornamented only with low radial folds, 

visible only on the shell.

Septa ceratitic; external lobe divided by a siphonal 

notch into two short branches; first lateral long; 

second lateral about two-thirds of the size of the first. 

Auxiliary series consisting of a straight row of denticulations on the umbilical slope. The antisiphonal lobe 

is flanked by a single internal lateral. The height of 

the last whorl is about twice its width and two-fifths 

of the total diameter. It is impressed by the inner 

whorl to one-fourth of its height and conceals slightly 

more than one-half of the inner whorl. The width of 

the umbilicus is two-fifths of the total diameter of the 

shell.

Horizon and locality: Xenodiscus waageni was 

found by A. M. Strong in the Owenites subzone of the 

Lower Triassic Meekoceras zone of the Inyo Range, 

1)2 miles east of Union Spring, on the old McAvoy 

trail across to Salinas Valley, 15 miles southeast of 

Independence, Inyo County, Calif. It was also found 

in the Meekoceras zone of southeast Idaho, at locality 

1, 5 miles east of Grays Lake; at locality 3, Wood

Canyon, Aspen Mountains, 9 miles east of Soda 

Springs. The species is associated with Meekoceras gracilitatis, M. mushbachanum, Flemingites russelli, Pledenstroemia kossmati, Aspenites acutus, Cordillerites angulatus, Lanceolites compactus, Ussuria waageni, Pseudosageceras multilobatum, Paranannites aspenensis, and 

other forms.

Xenodiscus whiteanus (Waagen)

Plate 25, Figure 17

1880. Meekoceras aplanatum (part). White, U. S. Geol. and 

Geog. Survey Terr. Twelfth Ann. Kept., pt. 1, pi. 31, 

fig. Ic (not figs, la, b, and d, == Flemingites aplanatus).

1895. Damibites whiteanus. Waagen, Fossils from the Ceratite 

formation: India Geol. Survey Mem., Palaeontologia 

Indica, 13th ser., Salt Range fossils, vol. 2, p. 290.

Shell small, evolute, discoidal, laterally compressed, 

slender, little embracing, whorls with convex flanks 

and venter. Septa ceratitic, with rounded saddles 

and three external serrated lobes. Surface ornamented 

with very fine transverse folds.

Xenodiscus whiteanus was included by White 71 

under what is now called Flemingites aplanatus, but an 

examination of the original in the United States 

National Museum failed to show any spiral striae 

that would throw the form under either Flemingites or 

Ophiceras. It is much too slender to be the young 

of F. aplanatus and also more slender than Xenodiscus 

waageni, the only form with which it might be compared. No other specimen than the one figured by 

White has ever been found, although the writer has 

collected at all the Triassic localities in Idaho frequently.

Horizon and locality: Very rare in the Lower 

Triassic Meekoceras zone in southeastern Idaho, at 

locality 2, Slug Creek, Aspen Mountains, about 14 

miles east of Soda Springs, associated with Meekoceras 

gracilitatis, M. mushbachanum, Flemingites russelli, 

Hedenstroemia kossmati, Aspenites acutus, Cordillerites 

angulatus, Lanceolites compactus, Ussuria waageni, 

Pseudosageceras multilobatum, and other forms.

Subgenus XENASPIS Waagen

1895. Xenaspis. Waagen, Fossils from the Ceratite formation: India Geol. Survey Mem., Palaeontologia 

Indica, 13th ser., Salt Range fossils, vol. 2, p. 161.

1895. Xenaspis. Diener, Triadische Cephalopodenfaunen der 

ostsibirischen Kiistenprovinz: Com. geol. [St.-Petersbourg] Mem., vol. 14, No. 3, p. 38.

1897. Xenaspis. Diener, Cephalopoda of the Lower Trias: 

India Geol. Survey Mem., Palaeontologia Indica, 

15th ser., Himalayan fossils, vol. 2, pt. 1, p. 83.

1902. Xenodiscus (part). Frech, Lethaea geognostica, Teil 1, 

Das Palaeozoicum, Band 2, Lief. 4, p. 634a.

1903. Proceratites. Kittl, Die Cephalopoden der oberen Werfener Schichten von Mud in Dalmatien: K.-k. geol. 

Reichsanstalt Wien Abh., Band 20, Heft.l, p. 28.

" White, C. A., U. S. Geol. and Qeog. Survey Terr. Twelfth Ann. Kept., pt. 1 

pi. 31, 1880.
XENODISCIDAE 47

1905. Xenaspis. Hyatt and Smith, The Triassic cephalopod

genera of America: U. S. Ceol. Survey Prof. Paper

40, p. 115. 

1911. Xenaspis. Arthaber, Die Trias von Albanien: Beitr.

Palaontologie Oesterr.-Ungarns u. des Orients, Band

24, p. 230.

Moderately long body chamber; whorl evolute, little 

embracing, discoidal; wide, shallow umbilicus, caused 

by the slow increase in height and thickness of the 

whorls. Lateral sculpture faint, the inner volutions 

being smooth. Septa ceratitic, lobes and saddles 

short, the two laterals longer than the external. The 

internal septa consist of a short, bifid antisiphonal 

lobe, flanked, by a lateral on the umbilical suture, 

which might be considered an auxiliary lobe. 

Waagen 72 first assigned this form to his genus Xenodiscus and then separated it from that group on 

account of its faint lateral sculpture, as contrasted 

with the strong folds of Xenodiscus plicatus Waagen, 

the type of the genus.

As thus defined Xenaspis is known in the upper 

Permian of the Salt Range and the Himalayas in 

India; the Lower Triassic Meekoceras zone of the Inyo 

Range in California; the Lower Triassic Columbites 

zone of Albania; and the Middle Triassic of eastern 

Siberia and India.

Frech,73 in his revision of the ammonites of the 

Permian, drops the genus Xenaspis as insufficiently 

differentiated from Xenodiscus. The writer has, 

however, retained the subgenus as Waagen defined it, 

because it seems to have given rise to the Gymnitidae, 

whereas Xenodiscus seems to have been the radicle of 

many of the highly ornamented ammonites of the 

Triassic. This separation is artificial but not more 

so than that in many other groups of Triassic ammonites. The confusion existing at present would 

not be helped by assigning all the evolute discoidal 

ceratitic ammonites of the Permian and Lower Triassic 

to Xenodiscus and Ophiceras, for the differentiation 

of these two genera is just as artificial and difficult 

as that of Xenaspis from Xenodiscus.

The Gymnitidae, Meekoceratidae, and Ceratitidae 

were certainly differentiated in the Lower Triassic, 

and it is probable that evolute discoidal ceratitic 

genera of all three families ought to be recognized in 

the Permian. Waagen's classification is an attempt 

to do this.

Xenodiscus (Xenaspis) marcoui Hyatt and Smith

Plate 7, Figures 26-33

1905. Xenaspis marcoui. Hyatt and Smith, The Triassic 

cephalopod genera of America: U. S. Geol. Survey 

Prof. Paper 40, p. 116, pi. 7, figs. 26-33.

" Wfwgen, W., Product-its limestone fossils: India Oeol. Survey Mem.) Palaeontologia Indica, 13th scr., Salt Range fossils, vol. l, p. 35, 1879.

73 Frcch, Fritz, Die Dyas: Lethaea geognostica, Teil 1, Das Palaeozoicum, Band 

2, Lief. 4, p. 03-la, 1902.

1927. Xenaspis cf. X. marcoui. Yehara, The Lower Triassic 

cephalopod and bivalve fauna of Shikoku: Japanese 

Jour. Geology and Geography, vol. 5, No. 4, p. 165, 

pi. 16, figs. 1-4.

Evolute, discoidal, laterally compressed. Whorl 

little embracing and little indented by the inner volution. Sides flattened convex, venter narrow and 

rounded. Umbilicus wide and shallow. The height 

of the last whorl is three-eighths of the diameter of 

the shell, and the width is two-thirds of the height. 

It is indented to about one-fourth of its height by the 

inner whorl. The width of the umbilicus is one-third 

of the total diameter.

The surface is ornamented with low radial folds, 

never forming ribs. The body chamber is at least a 

revolution long.

The septa are ceratitic. The ventral lobe is divided 

by a shallow siphonal saddle into two short goniatitic 

branches. The first and second laterals are serrated, 

and the auxiliary lobe is goniatitic. The antisiphonal 

lobe is long, narrow, and entire, flanked by a similar 

internal lateral on each side.

Xenaspis marcoui differs from X. carbonaria Waagen 

in the flattening of the whorl and in having the external 

lobe goniatitic instead of serrated:

Horizon and locality: This species was found by 

J. P. Smith in the Owenites sub zone of the Meekoceras 

zone of the Lower Triassic of the Inyo Mountains, in 

Union Wash, \% miles east of Union Spring, 15 miles 

southeast of Independence, Inyo County, Calif. It 

was associated with Meekoceras gracilitatis, M. mushbachanum, Flemingites aplanatus, Pseudosageceras multilobatum, and many other characteristic species of the 

Lower Triassic.

Xenodiscus (Xenaspis) nevadanus Smith, n. sp.

Plate 56, Figures 1-5

Shell of moderate size, evolute, discoidal, widely 

umbilicate, whorls little embracing and little indented 

by the inner whorls. Sides somewhat flattened, 

umbilical shoulders very abrupt, ventral shoulders 

gently rounded, venter rather narrow and rounded. 

Surface nearly smooth, with very gentle transverse 

folds. Septa serrated, with entire saddles, and three 

external serrated lobes, no auxiliary being visible above 

the umbilical suture.

The height of the whorl is greater than one-fourth 

of the diameter of the shell; the width of the last 

whorl is three-fourths of the height; the indentation 

is one-seventh of the height. The width of the umbilicus is three-sevenths of the diameter of the shell. 

The largest specimen found had a diameter of 50 millimeters and was entirely septate.

Xenodiscus nevadanus is not nearly related to any 

other species of American fauna.
48 LOWER TRIASSIC AMMONOIDS OF NORTH AMERICA

Horizon and locality: Rather rare in the Owenites 

subzone of the Lower Triassic, of .the Phelan ranch on 

the east side of the Elko Mountains, at the mouth of 

Cottonwood Canyon, Elko County, Nev.; associated 

with Meekoceras gracilitatis, Owenites cf. 0. koeneni, 

Lanceolites bicarinatus, Inyoites oweni, Pseudosageceras 

multilobatum, Anasibirites desertorum, and other forms.

Genus OPHICERAS Griesbach

1880. Ophiceras. Griesbach, Palaeontological notes on the

Lower Trias of the Himalayas: India Geol. Survey

Rec., vol. 13, p. 109. 

1895. Ophiceras. Diener, Triadische Cephalopodenfaunen der

ostsibirischen Kiistenprovinz: Com. geol. [St.-Petersbourg] Mem., vol. 14, No. 3, p. 43. 

1897. Ophiceras. Diener, Cephalopoda of the Lower Trias:

India Geol. Survey Mem., Palaeontologia Indica,

15th ser., Himalayan fossils, vol. 2, pt. 1, p. 100. 

1902. Ophiceras. Frech, Lethaea geognostica, Teil 1, Das

Palaeozoicum, Band 2, Lief. 4, p. 636. 

1905. Ophiceras. Hyatt and Smith, The Triassic cephalopod

genera of America: U. S. Geol. Survey Prof. Paper 40,

p. 117. 

1913. Ophiceras. Diener, Triassic faunae of Kashmir: India

Geol. Survey Mem., Palaeontologia Indica, new ser.,

vol. 5, Mem. 1, p. 14. 

1922. Ophiceras. Welter, Die Ammoniten der Unteren Trias

von Timor: Palaeontologie von Timor, Lief. 11, Abh.

19, p. 103. 

1927. Ophiceras. Yehara, The Lower Triassic cephalopod and

bivalve fauna of Shikoku: Japanese Jour. Geology

and Geography, vol. 5, No. 4, p. 161.

Not 1929. Ophiceras. Mathews, The Lower Triassic cephalopod fauna of the Fort 'Douglas area, Utah: Walker

Mus. Mem., vol. 1, No. 1, p. 4.

Type: Ophiceras tibeticum Griesbach.74 

Evolute, little embracing; whorls increasing slowly 

in height; umbilicus wide and moderately deep. Surface ornamented with faint folds and cross striae, 

sometimes with coarse lateral ribs in age. The inner 

casts are ornamented with a delicate spiral striation, 

formed by the inner pearly layer of the shell, which is 

unknown on any other group of ammonites, although 

Flemingites, Sturia, and some shells of Ceratites and 

Tropites have the external striation. On account of 

this peculiar sculpture Diener classes this genus with 

the Gymnitinae, along with Flemingites.

The septa are ceratitic; the lobes and saddles usually 

ong and narrow, there being the usual namber, the 

divided external, the two laterals, and the small auxiliary on the umbilical shoulder. Mojsisovics 75 described under the name of Xenodiscus karpinskyi a 

species that may belong to Ophiceras. Waagen 76 

thought that of the species described by Griesbach as 

Ophiceras, only 0. tibeticum could remain under that

M Griesbach, C. L., Palaeontological notes on the Lower Trias of the Himalayas: 

India Geol. Survey Rec., vol. 13, p. 109, pi. 3, figs. 1-7, 1880.

75 Mojsisovics, E. von, Arktische Triasfaunen: Acad. imp. sci. St.-Petersbourg 

M6m., 7th ser., vol. 33, No. 6, p. 75, 1886.

70 Waagen, W., Fossils from the Ceratite formation: India Geol. Survey Mem., 

Palaeontologia Indica, 13th ser., Salt Range fossils, vol. 6, pt. 2, p. 209, 1895.

genus and that the others should be classed under 

Gyronites. Mojsisovics 77 at first considered Ophiceras 

merely as a synonym of Xenodiscus. In a later work 

he still considered most species of Ophiceras to belong 

to Xenodiscus, but 0. himalayanum Griesbach and X. 

plicatus Waagen he placed in the group of Ceratites 

obsoleti, to which he afterward gave the name of 

Danubites.

It will be seen from this review that this genus has 

been variously misinterpreted or else ignored, and 

Waagen's recognition of even one species was due to 

his mistake of supposing that there was an adventitious 

lobe. This lobe has been shown by Diener not to 

exist on the type, and Waagen's error was due to a 

poor drawing.

Ophiceras resembles Danubites, from which it is 

distinguished by its spiral sculpture on the inner layer 

of the shell; from Xenaspis it is distinguished in the 

same way, also by its shorter body chamber; from 

Xenodiscus, by these same characters and by its 

fainter sculpture on the inner whorls. Gyronites is 

much more difficult to separate from Ophiceras because 

of the uncertainty of its characters; many species that 

were assigned by Waagen to Gyronites may belong to 

Ophiceras, but the diagnostic mark, the spiral striation, appears only on the cast, as that disappears when 

the shell is preserved, and also when the specimen is 

poorly preserved. Ophiceras is characteristic of the 

Lower Triassic, being known in beds of that age in 

India and eastern Siberia, in the Meekoceras zone in 

the Aspen Mountains of Idaho, and in the same zone 

in the Inyo Range of California and in the Columbites 

zone of Idaho and Albania.

Frech 78 assigns the Ophiceras beds of India and 

Siberia to the upper Permian, but there is no longer 

any question of the abundant occurrence of Ophiceras 

in the Lower Triassic in Asia, Europe, and western 

America.

Ophiceras dieneri Hyatt and Smith

Plate 8, Figures 16-29

1905. Ophiceras dieneri. Hyatt and Smith, The Triassic 

cephalopod genera of America: U. S. Geol. Survey 

Prof. Paper 40, p. 118, pi. 8, figs. 16-29.

Evolute, discoidal, laterally compressed, widely 

umbilicate. Whorls little embracing and little indented by the inner volution. The height of the whorl 

is less than one-third of the total diameter of the shell, 

and the width is three-fourths of the height. It 

embraces about one-third of the inner volution. The 

width of the umbilicus is nearly half the total diameter 

of the shell. The umbilical shoulders are rounded,

77 Mojsisovics, E. von, Die Cephalopoden der Mediterranen Triasprovinz: K.-k 

geol. Reichsanstalt Wien Abh., vol. 10, p. 232, 1882.

78 Frech, Fritz, Lethaea geognostica, Teil 1, Das Palaeozoicum, Band 2, Lief. 4, 

pp. 628-639, 1902.
XENODISCIDAE 49

with gentle inward slope; the flanks are convex, 

with the greatest width at half the height of the whorl. 

The abdominal shoulders are abrupt, subangular; 

the venter flat and rather narrow. There are no ribs 

on the shell but only low radial folds. The surface 

is ornamented with fine spiral lines, which are seldom 

preserved. This ornamentation is the distinguishing 

character of the genus.

The septa are ceratitic. The external lobe is divided 

by a short, narrow, siphonal saddle into two small 

unserrated lobes; the first lateral lobe long and narrow, 

the second very small. Both lateral lobes are slightly 

serrated; on the umbilical suture there is a small 

auxiliary, unserrated.

TMs species is most nearly related to Ophiceras 

demissum Oppel, as figured and described by Diener.79 

But in the Indian species the radial sculpture is stronger 

and the spiral lines weaker than on Ophiceras dieneri. 

The faunal association of the two is approximately 

the same, and the differences here rioted are not 

greater than those often found between varieties of the 

same species.

Horizon and locality: In the Lower Triassic Meekoceras zone of southeastern Idaho, in the Aspen Mountains, Wood Canyon, 9 miles east of Soda Springs; 

associated with Meekoceras gracilitatis, M. mushbachanum, Flemingites russelli, F. aplanatus, Clypeoceras, 

Hedenstroemia, Xenodiscus, and many other forms 

characteristic of the Meekoceras zone.

Ophiceras jacksoni Hyatt and Smith

Plate 62, Figures 11-21

1905. Prionolobus jacksoni. Hyatt and Smith, The Triassic 

cephalopod genera of America: U. S. Geol. Survey 

Prof. Paper 40, p. 151, pi. 62, figs. 11-21.

Form evolute, discoidal, laterally compressed. 

Whorls of moderate height but increasing slowly in 

height; rather deeply embracing, and deeply indented 

by the inner volutions. Sides flattened, umbilical 

shoulders gently rounded, venter highly arched and 

narrow; no ventral shoulders perceptible. Umbilicus 

wide and shallow. The height of the whorl is about 

two-fifths of the total diameter of the shell, and the 

width half of the height. The indentation is somewhat 

less than one-third of the height. The width of the 

umbilicus is about three-tenths of the total diameter of 

the shell.

The surface is smooth, ornamented only with cross 

striae of growth and very fine spiral lines. The septa 

are ceratitic, lobes all serrated, and saddles all rounded 

and entire. The general character of the septa is the

78 Dionor, Cnrl, Cephalopoda of the Lower Trias: India Oeol. Survey Mem., 

Palacontologia Indicn, 15th ser., Himalayan fossils, vol. 2, p. 121, pi. 14, figs. 1-7, 

1897.

same as that of Meekoceras s. s., but there is no fourth 

lateral lobe; instead there is a long, straight row of 

denticulations. This character of the septation was 

supposed to distinguish Prionolobus from Ophiceras, 

which is very similar to it in form and character. But 

now Prionolobus has been definitely discarded, and 

this species would then fall under Ophiceras.

Ophiceras jacksoni differs from Xenodiscus waageni 

in being more robust and involute and in the more 

rapid increase in height of the whorls. It differs from 

Ophiceras spencei in the character of the septa and in 

lacking the constrictions that occur on the cast of that 

species. It does not resemble closely any of the Indian 

species ascribed by Waagen to Prionolobus but agrees 

with them all in having the straight row of denticulations instead of the auxiliary lobe.

Horizon and locality: Ophiceras jacksoni is common 

in the Lower Triassic Columbites zone above the Meekoceras zone 1 mile west of Paris, Idaho, locality 1981, 

United States Geological Survey, associated" with 

Columbites parisianus, Meekoceras pilatum, Pseudosageceras multilobatum, Ophiceras spencei, Celtites 

ursensis, and many others. What is probably the 

same species was found in the Meekoceras zone in Wood 

Canyon, 9 miles east of Soda Springs, Idaho, and in 

the Owenites subzone in Union Wash, in the Inyo 

Range, 1}£ miles east of Union Spring, 15 miles southeast of Independence, Inyo County, Calif.

The figured specimens all came from locality 1981, 

near Paris, Idaho, and are in the collection of the 

United States Geological Survey.

Ophiceras parvum Smith, n. sp.

Plate 54, Figures 25-30

Shell small, discoidal, laterally compressed, widely 

umbilicate; whorls higher than wide, with abrupt ventral and umbilical shoulders, gently sloping sides, and 

rather narrow flattened venter. Surface with very 

weak folds and fine growth lines. Septa with four 

external serrated lobes and three rounded saddles. 

These lobes have the conventional shape of the genus, 

somewhat compressed and elongate.

Ophiceras parvum is closely related to 0. subguadratum, with which it is associated, differing chiefly in the 

more compressed whorl and narrower umbilicus. It 

is not closely related to any of the Asiatic species of 

this genus.

Horizon and locality: Rather common in the Lower 

Triassic Owenites subzone of the Meekoceras zone, in 

Union Wash, Inyo Mountains, about 15 miles southeast of Independence, Inyo County, Calif., associated 

with Meekoceras gracilitatis, Owenites koeneni, Inyoites 

oweni, Anasibirites desertorum, A. noetlingi, Lanceolites bicarinatus, and other forms..
50 LOWER TRIASSIC AMMONOIDS OF NORTH AMERICA

Ophiceras sakuntala Diener

Plate 54, Figures 1-17; Plate 56, Figures 13-18

1897. Ophiceras sakuntala. Diener, Cephalopoda of the Lower 

Trias: India Geol. Survey Mem., Palaeontologia 

Indica, 15th ser., Himalayan fossils, vol. 2, pt. 1, p. 

114, pi. 10, figs. 1-7; pi. 11, figs. 1, 2, 4.

1911. Ophiceras sakuntala. Arthaber, Die Trias von Albanien: 

Beitr. Palaontologie Oesterr.-TJngarns u. des Orients, 

Band 24, p. 239, pi. 21, fig. 4.

Form evolute, discoidal, laterally compressed, widely 

umbilicate, sides flattened, venter narrowly rounded. 

Surface with very fine radial lines and weak folds. 

Septa ceratitic, with three rounded saddles and four 

elongate serrated lobes, of which the first lateral is 

much the largest.

Ophiceras sakuntala was first described from the 

Lower Triassic of India; it has since been found in the 

Lower Triassic Columbites zone of Albania.

Horizon and locality: Rare in the Lower Triassic 

Owenites subzone of the Meekoceras zone in Union 

Wash, Inyo Mountains, about 15 miles southeast of 

Independence, Inyo County, Calif.; also very rare in 

the same zone at the mouth of Cottonwood Canyon, 

about 4 miles southwest of the Phelan ranch, east side 

of the Ruby Range, about 70 miles south of Wells, Nev. 

At both localities it was associated with Meekoceras 

gracilitatis, M. mushbachanum, 'Inyoites oweni, Owenites koeneni, Anasibirites desertorum, Lanceolites bicarinatus, Pseudosageceras multilobatum, and other 

characteristic species.

Ophiceras spencei Hyatt and Smith

Plate 62, Figures 1-10

1905. Ophiceras spencei, Hyatt and Smith, The Triassic cephalopod genera of America: U. S. Geol. Survey Prof. 

Paper 40, p. 119, pi. 62, figs. 1-10.

Evolute, discoidal, laterally compressed. Whorl of 

medium height but increasing slowly. Deeply embracing; deeply indented by the inner volutions. 

Umbilical shoulders abruptly rounded, sides flattened; 

venter rounded, bordered by rounded but rather 

abrupt abdominal shoulders. The outer, whorl envelops a little over half of the inner and is indented to 

one-fourth of its height. The height of the whorl is 

two-fifths of the total diameter of the shell, and the 

width is five-eighths of the height. The umbilicus is 

wide and shallow, being slightly less than one-third 

of the total diameter of the shell.

The surface is ornamented with numerous weak forward-curving constrictions, visible chiefly on the cast, 

and with fine cross striae of growth, visible only on the 

outer shell.

Septa ceratitic, with entire saddles, a divided external lobe, two principal laterals and an auxiliary, all 

serrated.

The form greatly resembles that of Ophiceras jacksoni, from which Ophiceras spencei may easily be distinguished by the sculpture and the individualized 

auxiliary lobe. This species also resembles Ophiceras 

ptychodes Diener, of the' Lower Triassic Otoceras beds 

of India, but has slightly weaker sculpture than the 

Indian species, the folds being weaker and more 

strongly curved.

The two species agree in outer form and septa and in 

having the folds 011 the cast and only the cross striae of 

growth visible on the outer shell. The two species 

might well be considered as only varieties of the same 

form, if the association in which the two occur were 

not different. The Otoceras beds in India, in which 

Ophiceras ptychodes occurs, are now regarded by some 

authors as Permian; but the associated species in the 

Idaho beds make such a reference extremely improbable, especially as several of the species are also 

common at the Meekoceras gracilitatis horizon, of the 

age of which there can be no ques'tion.

Horizon and locality: Ophiceras spencei is rare in the 

Lower Triassic Columbites zone 1 mile west of Paris, 

Bear Lake County, Idaho, in brownish bituminous 

limestones, associated with Columbites parisianus, 

Meekoceras pilatum, Ophiceras jacksoni, Pseudosageceras, Celtites, and many others less characteristic. 

The horizon lies above that of Meekoceras gracilitatis, 

which occurs near by in gray limestones like those of 

the Aspen Mountains near Soda Springs.

Ophiceras subquadratum Smith, n. sp.

Plate 54, Figures 18-24

Shell small, robust, widely umbilicate, with abruptly 

rounded umbilical and subangular ventral shoulders. 

Whorls subquadratic in section, slightly higher than 

wide. Surface smooth, without ribs or folds.

Septa ceratitic, with very short ventral lobes, long 

and narrow first lateral, small second lateral, and no 

auxiliary. The height of the last whorl is two-fifths of 

the diameter of the shell, the width is slightly less than 

the height, and the width of the umbilicus is one-third 

of the diameter of the shell.

Ophiceras subquadratum is rather closely related to 

0. parvum, with which it is associated, differing in its 

more robust whorls and greater evolution.

Horizon and locality: Rather common, in the 

Owenites subzone of the Meekoceras zone in Union 

Wash, Inyo Mountains, Inyo County, Calif., associated with Meekoceras gracilitatis, Inyoites oweni, 

Owenites koeneni, Lanceolites bicarinatus, Anasibirites 

noetlingi, A. desertorum, Pseudosageceras multilobatum, 

and other forms. It is rather rare at the same horizon 

at the mouth of Cottonwood Canyon, 4 miles southwest of the Phelan ranch, east side of the Ruby Range,
XENODISCIDAE 51

70 miles south of Wells, Nev., in approximately the 

same association.

Genus FIEMINGITES Waagen

1892. Flemingiles. Waagen, Preliminary notice on the Triassic 

deposits of the Salt Range: India Geol. Survey Rec., 

vol. 25, pt. 4, p. 184.

1892. Flemingiles. Waagen, Vorlaufige Mittheilung iiber die 

Ablagerungen der Trias in der Salt Range: K.-k. geol. 

Reichsanstalt Wien Jahrb., Band 42, pt. 2, p. 380.

1895. Flemingites. Waagen, Fossils from the Ceratite formation: India Geol. Survey Mem., Palaeontologia Indica, 

13th ser., Salt Range fossils, vol. 2, p. 185.

1897. Flemingites. Diener, Cephalopoda of the Lower Trias: 

India Geol. Survey Mem., Palaeontologia Indica, 15th 

ser., Himalayan fossils, vol. 2, pt. 1, p. 90.

1902. Flemingites. Frech, Lethaea geognostica, Teil 1, Das 

Palaeo/oicum, Band 2, Lief. 4, p. 638.

1902. Flemingites. Frech, Ueber Trias-Ammoniten aus Kaschmir: Centralbl. Mineralogie, Band 3, No. 5, p. 134.

1904. Flemingites. Smith, The comparative stratigraphy of 

the marine Trias of western America: California Acad. 

Sci. Proc., 3d ser.; vol. 1, p. 377.

1905. Flemingites. Hyatt and Smith, The Triassic cephalopod 

genera of America: U. S. Geol. Survey Prof. Paper 40, 

p. 120.

1909. Flemingiles. Krafft and Diener, Lower Triassic Cephalopoda from Spiti, Malla Johar, and Byans": India Geol. 

Survey Mem., Palaeontologia Indica, 15th ser., vol. 

6, Mem. 1, p. 106.

1913. Flemingites. Diener, Triassic faunae of Kashmir: India 

Geol. Survey Mem., Palaeontologia Indica, new ser., 

vol. 5, No. 1, p. 20.

1922. Flemingiles. Welter, Die Ammoniten der Unteren Trias 

von Timor: Palaeontologia von Timor, Lief. 11, Abh. 

19, p. 113.

Type: " Ceratites" flemingianus De Koninck,80 from 

the Lower Trias of the Salt Range.

Form evolute, little embracing; wide, shallow 

umbilicus; whorls robust, usually a little higher than 

wide, increasing very slowly in size; sides rounded; 

venter somewhat flattened and usually considerably 

narrower than the greatest breadth of the whorl. 

Strong, lateral cross ribs or folds, which are never 

dichotomous and do not cross the venter, are commonly 

present. Strong, fine spiral ridges on all parts of the 

external shell, appearing also on the casts.

Septa distinctly ceratitic, with rounded entire saddles and long serrated lobes, of which there are an 

external lobe divided by a broad siphonal saddle, two 

principal laterals, and an auxiliary. In more specialized forms the siphonal saddle is broken up by secondary divisions that almost reach the importance of 

adventitious lobes.

Waagen compares this; genus with Ceratites but 

notes that the form is more evolute and the spiral lines 

stronger than on that genus, also that the lateral 

sculpture does not break up into knots or dichotomousribs. He places Flemingites in the Leiostraca, in spite

s° De Koninck, L., Oeol. Soc. London Quart. Jour., vol. 19, p. 10, pi. 7, flg. 1,1863.

of the coarse ribs that occur on most species of the 

genus.

Flemingites is one of the most definite and consistent 

genera in the Lower Triassic. Its young stages are 

decidedly like Prolecanites, and its immediate ancestor 

almost certainly Ophiceras. It is almost entirely confined to the Pseudosageceras multilobatum subzone of 

the Meekoceras zone of the Lower Triassic.

In America the genus is represented by Flemingites 

aplanatus White, F. aspenensis Smith, F. bannockensis 

Smith, F. cirratus White, F. russelli Hyatt and Smith, 

F. russelli var. gracilis Smith.

Flemingites aplanatus (White)

Plate 11, Figures 1-14; Plate 22, Figures 1-23; Plate 39, Figures 

1, 2; Plate 64, Figures 17-32

1879. Meekoceras aplanatum. White, U. S. Geol. and Geog. 

Survey Terr. Bull., vol. 5, p. 112.

1880. Meekoceras aplanatum. White, U. S. Geol. and Geog.

Survey Terr. Twelfth Ann. Rept., pt. 1, p. 112, pi. 31,

fig. 1 a, b, d (not fig. c, which is Danubites whileanus

Waagen). 

1886. Xenodiscus aplanatus. Mojsisovics, Arktische Triasfaunen: Acad. imp. sci. St.-Pe'tersbourg Mem., 7th

ser., vol. 33, No. 6, p. 75. 

1895. Xenaspis? aplanata. Waagen, Fossils from the Ceratite

formation: India Geol. Survey Mem., Palaeontologia

Indica, 13th ser., Salt Range fossils, vol. 2, p. 290. 

1900. Wyomingites aplanatus. Hyatt, Cephalopoda, in Zittel,

K. A. von, Textbook of palaeontology (translated by

C. R. Eastman), p. 556. 

1902. Ophiceras aplanatum. Frech, Lethaea geognostica, Teil

1, Das Palaeozoicum, Band 2, Lief. 4, p. 631, fig. e.

1904. Meekoceras aplanatum. Smith, The comparative stratigraphy of the marine Trias of western America: 

California Acad. Sci. Proc., 3d ser., vol. 1, p. 373, 

pi. 41, figs. 4-6.

1905. Meekoceras aplanatum. Hyatt and Smith, The Triassic 

cephalopod genera of America: U. S. Geol. Survey 

Prof. Paper 40, p. 146, pi. 11, figs. 1-14; pi. 64, figs. 

17-22; pi. 77, figs. 1, 2.

Evolute, discoidal, laterally compressed; wide, 

shallow umbilicus; whorls increasing slowly in height, 

little embracing, outer whorl concealing but little of 

the inner and indented to less than one-fourth of its 

height by it. Breadth of whorl a little over half its 

height, and one-fifth of the diameter of the shell; 

height of whorl a little more than one-third of the 

total diameter. Width of umbilicus equal to height of 

whorl. Umbilical shoulders abruptly rounded but not 

angular. Sides gently rounded, greatest breadth of 

whorl at a point half way between the base and the 

venter. Abdomen flattened, narrow, with subangular 

abdominal shoulders.

Surface ornamented with cross striae and folds, which 

may become quite strong on the body chamber. 

Numerous typical specimens from the type locality 

and other localities show strong spiral striae on the 

shell, thus placing the species in the group of Fleming-
52 LOWER TRIASSIC AMMONOIDS OF NORTH AMERICA

ites rohilla Diener, somewhat intermediate between 

Ophiceras and typical Flemingites.

Septa ceratitic, saddles all rounded and entire, 

lobes partly serrated, partly entire. The external 

lobe is divided by a shallow siphonal saddle into two 

narrow branches, which are slightly denticulate, 

though usually entire. These divisions of the lobe 

fall upon the abdominal shoulder angles. The first 

lateral lobe is distinctly serrated, longer than the 

external, and much wider; the second lateral is usually 

entire, although in some specimens it ma3r be slightly 

denticulated. There is no auxiliary series. The 

internal septa consist of a short bifid antisiphonal 

lobe and a short, shallow entire lateral, just inside 

the umbilical suture. These septa are very like those 

of Xenaspis Waagen, except in the difference in the 

sizes of the lobes. This resemblance becomes more 

significant when it is known that Flemingites aplanatus 

has a body chamber at least three-quarters of a revolution in length.

F. aplanatus White resembles in form Gyronites 

freguens Waagen 81 but differs in lacking the auxiliary 

lobe. It also agrees in septa with Gyronites nangaensis 

Waagen82 but is slightly more involute than that 

species and has the lobes not so long.

Relative dimensions of Flemingites aplanatus

Diameter. _______________________________ 100

Height of last whorl________-_____________ 37

Height of last whorl from the preceding-..-- 27

Width of last whorl._______________ 20

Width of umbilicus-_-__-___-------_-_____ 37

Involution-_____________________________ 10

In small specimens the whorl is more robust, broader 

in proportion to its height, and more deeply embracing, although the form is always evolute, even in the 

early stages of growth. The young whorls are rounded, 

the angular shoulders being a character of adolescence. 

The adolescent shell agrees in all respects with Lecanites, and this species gives a transition from that 

genus through Xenodiscus to Flemingites.

Hyatt 83 took F. aplanatus as the type of a new but 

undescribed genus Wyomingites, but this statement 

was intended to refer to the form described by Waagen 

as Gyronites whiteanus and not to the typical F. 

aplanatus. It was unknown to Hyatt that Waagen 

had already renamed this form.

Horizon and locality: Flemingites aplanatus White 

was found by the United States Geological Survey 

in the Lower Triassic Meekoceras zone in southeastern 

Idaho, about 5 miles southeast of Grays Lake (locality 

1, United States Geological and Geographical Survey

81 Waagen, W., Fossils from the Ceratite formation: India Geol. Survey Mem., 

Palaeontologia Indica, 13th ser., Salt Range fossils, vol. 2, p. 292, pi. 33, figs. J-4, 

1895.

82 Idem, p. 297, pi. 32, fig. 5 a-c.

83 Hyatt, Alpheus, Cephalopoda, in Zittel, K. A. von, Textbook of palaeontology 

(translated by C. R. Eastman), p. 556, 1900.

of the Territories), and also about 15 miles a little 

west of south from the lake. Alpheus Hyatt also 

found it in Wood Canyon, Aspen Mountains, 9 miles 

east of Soda Springs, Idaho. J. P. Smith found it in 

the Lower Triassic Meekoceras zone of the Inyo Range, 

east side of Owens Valley in Union Wash, near Union 

Spring, about 15 miles southeast of Independence, 

Inyo County, Calif.

Flemingites aspenensis Smith, n. sp.

Plate 23, Figures 6-11

Shell of moderate size, discoidal, evolute, widely 

umbilicate, little embracing, and little impressed by 

the inner whorl. Umbilicus shallow, with abrupt 

shoulders; sides flattened but converging slightly 

toward the sub angular ventral shoulders that border 

the flat narrow venter. Surface with weak folds and 

strong spiral lines. Septa ceratitic, with entire 

saddles and four serrated lobes, of which the ventral 

is short and narrow, the first lateral rather large, the 

second lateral small, and the auxiliary barely individualized.

Flemingites aspenensis is very closely related to 

F. rohilla Diener, of the Lower Triassic Pledenstroemia 

beds of India, differing in its smaller size and less 

individualized auxiliary lobe. It is also very like 

F. aplanatus, with which it is associated, differing in 

its more compressed and slightly more involute whorls.

Horizon and locality: Rather common in the 

Lower Triassic Meekoceras zone of southeastern 

Idaho, at locality 1, 5 miles southeast of Grays Lake; 

at locality 2, Slug Creek, Aspen Mountains, 14 miles 

east of Soda Springs; at locality 3, head of Wood 

Canyon, Aspen Mountains, 9 miles east of Soda 

Springs, associated with Meekoceras gracilitatis, M. 

mushbachanum, Flemingites russelli, Hedenstroemia 

kossmati, Cordillerites angulatus, Lanceolites compactus, 

Aspenites acutus, Pseudosageceras muitilobatum, and 

other forms.

Flemingites bannockensis Smith, n. sp.

Plate 23, Figures 18-26

Shell of moderate size, discoidal, widely umbilicate, 

evolute, little embracing, and little impressed by the 

inner whorl. Cross section subquadratic, with abruptly 

rounded, almost subangular ventral and umbilical 

shoulders, flattened sides, and rather broad, flattened 

venter. Surface with very strong spiral lines, visible 

on the outer shell and the cast. Septa ceratitic, with 

three well-defined saddles and four external lobes, of 

which the auxiliary on the umbilical slope is only 

slightly individualized.

Flemingites bannockensis is very closely related to 

F. aplanatus, from which it differs in the wider umbilicus, squarer whorls, weaker sculpture, and slower rate 

of increase of height of the whorls. It differs from F.
XENODISCIDAE 53

aspenensis in the thicker whorls, wider umbilicus, 

and slower rate of increase, as well as in the much 

stronger spiral lines.

Horizon and locality: Very rare in the Lower Triassic zone of M&elcocenis, in southeastern Idaho, at 

locality 1, 5 miles southeast of Grays Lake; at locality 

2, Slug Creek, Aspen Mountains, 14 miles east of Soda 

Springs. The species is associated with Meekoceras 

gracilitatis, M. mushbachanum, Flemingites russelli, F. 

aplanatus, Hedenstroemia kossmati, Cordillerites anguIcitus, Lanceolites compactus, Aspenites acutus, Pseudosageceras multilobatum, and other forms.

Flemingites cirratus (White)

Plate 20, Figure 1; Plate 26, Figures 1-12

1SSO. Arcesles cirratus. White, Triassic fossils of southeastern 

Idaho: U. S. Geol. and Geog. Survey Terr. Twelfth 

Ann. Kept., pt. 1, p. 116.

Shell very large, evolute, laterally compressed, little 

embracing, with abrupt umbilical shoulders, flattened 

sides, abruptly rounded ventral shoulders, and rounded 

venter. Ornamented with very strong spiral ridges 

but lacking the transverse ribs that are usual on 

Flemingites. Septa ceratitic, with entire rounded saddles, and four strongly serrated external lobes.

The height of the last whorl is one-third of the diameter of the shell; the width is half the height; the 

width of the umbilicus is nearly one-third of the diameter of the shell. The outer whorl embraces half of 

the inner and is indented to one-eighth of the height.

The young shells go through a stage resembling 

Lecanites, at a diameter of 5 to 10 millimeters, followed 

by one resembling Xenodiscus, at a diameter of about 

12 millimeters.

Flemingites cirratus was described as Arcestes but has 

no resemblance to that genus. An examination of the 

very poor type specimen in the United States National 

Museum made the identification possible, for White's 

type was very briefly described and never figured.

Flemingites cirratus is a member of the typical group 

of the genus and very closely related to F. salya 

Diener,84 from the Flemingites or Hedenstroemia beds 

of India; the two might even be identical, but neither 

is sufficiently well preserved or well enough known for 

such an identification to be more than conjectural.

It is also very similar to F.flemingianus De Koninck, 

from the Salt Range of India, but is more involute and 

lacks the strong lateral folds of the Indian species. F. 

flemingianus is the type of the genus and one of the 

largest members, rivaled closely by its American 

kinsman.

Horizon and locality: Rather rare in the Lower 

Triassic Meekoceras zone of southeastern Idaho, at 

locality 1, 5 miles southeast of Grays Lake; at Rohner's

84 Tlio Cephalopoda of the Lower Trias: India Oeol. Survey Mem., Palaeontologin Indicoj 15th scr., vol. 2, pt. 1, p. 90, pi. 19, figs. 1, a-b, 1897.

ranch, mouth of Paris Canyon, 1 mile west of Paris; at 

locality 3, hea'd of Wood Canyon, Aspen Mountains, 9 

miles east of Soda Springs; associated with Meekoceras 

gracilitatis, M. mushbachanum, Flemingites russelli, 

Hedenstroemia kossmati, Aspenites acutus, Cordillerites 

angulatus, Lanceolites compactus, Ussuria waageni, 

Paranannites aspenensis, and other forms.

Flemingites russelli Hyatt and Smith

Plate 1, Figures 1-3; Plate 26, Figures 14-23; Plate 70, 

Figures 1-3

1904. Flemingites russelli (Hyatt and Smith MS.). Smith, The 

comparative stratigraphy of the marine Trias of western America: California Acad. Sci, Proc., 3d ser., vol. 

1, p. 378, pi. 42, fig. 5; pi. 43, figs. 5, 6.

1905. Flemingites russelli, Hyatt and Smith, The Triassic cephalopod genera of America: U. S. Geol. Survey Prof. 

Paper 40, p. 121, pi. 1, figs. 1-3; pi. 70, figs. 1-3.

Evolute, discoidal, laterally compressed; wide umbilicus; whorls not deeply embracing, outer whorl covering only one-third of the inner and indented by it 

to about one-sixth of its height. This, feature shows 

that although the form is evolute the increase in height 

of whorls is great. Umbilicus shallow and umbilical 

shoulders rounded; sides gently convex. Whorls 

twice as high as broad; venter narrow and somewhat 

rounded. Sides ornamented with strong folds in 

mature shell, nearly smooth in young shells. Surface 

of cast ornamented with fine, distinct spiral lines. 

Septa ceratitic, four serrated lobes and three rounded 

entire saddles on each side. The external lobe is 

broad, divided by a deep siphonal saddle. The first 

lateral is twice as long as the external and has about 

four serrations; the second lateral is narrow; and the 

auxiliary series consists of four or five denticulations, 

forming a broad lobe. The saddles are all similar in 

shape and broader than the lobes.

Dimensions of the type specimen of Flemingiles russelli

Millimeters 

Diameter._______________________________ 104

Height of last whorl____________________ 37

Height of last whorl from preceding. _ ______ 30

Width of last whorl.____.________________ 20 .

Involution._____________________________ 7

Width of umbilicus--_---------------_--__ 32

Horizon and locality: In the Lower Triassic Meekoceras zone of Wood Canyon, Aspen Ridge, 9 miles east 

of Soda Springs, Idaho; associated with Pseudosageceras, Meekoceras gracilitatis White, M. (JKoninckites) 

mushbachanum White.

Flemingites russelli Hyatt and Smith var. gracilis Smith, n. var.

Plate 23, Figures 1-5

Shell large, evolute, discoidal, laterally compressed, 

widely umbilicate, little embracing, and little indented 

by the inner whorl. Surface with gentle radial folds
54 LOWER TRIASSIC AMMONOIDS OF NORTH AMERICA

and weak spiral lines. Septa ceratitic, with rounded 

saddles and four external serrated lobes.'

Flemingites russelli var. gracilis differs from the 

typical species in its greater evolution, wider umbilicus, 

and slower increase in the height of its whorl. These 

differences are hardly specific, and the two seem to 

intergrade.

Horizon and locality: Rare in the Lower Triassic 

Meekoceras zone of southeastern Idaho, at locality 2, 

Slug Creek, Aspen Mountains, 14 miles east of Soda 

Springs; associated with the typical form of F. russelli, 

Meekoceras gracilitatis, Hedenstroemia kossmati, Cordillerites angulatus, Lanceolites compactus, Ussuria waageni, Pseudosageceras multilobatum, Aspenites acutus, 

and other forms.

Family MEEKOCERATIDAE

Form laterally compressed, discoidal, evolute in the 

primitive genera, involute in more specialized groups. 

Surface smooth or ornamented with weak folds, more 

rarely with distinct ribs. Body chamber short. 

Septa goniatitic or ceratitic, becoming slightly 

ammonitic in a few species. The Meekoceratidae have 

commonly been regarded as a subfamily under the 

Ptychitidae, but they differ from that group in their 

more compressed form and evolute discoidal young, 

which resemble the genus Lecanites, the probable 

radicle of the family.

Waagen 85 was the first to class this group as an 

independent family, on account of the large number of 

genera or subgenera in it and the evident phylogenetic 

relationship between them. This family, as Waagen 

defines it, is the most homogeneous among Triassic 

ammonites, the most perfect gradation existing between 

the genera composing it, so much so that Diener has 

regarded all the Meekoceratidae as belonging to the 

genus Meekoceras, with the exception of Anasibirites, 

more recently assigned to this family.

The Meekoceratidae are composed of Meekoceras 

(with the so-called subgenera Gyronites, Koninckites, 

Prionolobus and Kingites*), Anasibirites, Hedenstroemia, 

Dagnoceras, Clypeoceras, and Beyrichites, all occurring 

in the Lower Triassic, except Beyrichites, and all the 

others confined to that division except Clypeoceras, 

which is found rarely in the Middle Triassic. 

Beyrichites is characteristic of the Middle Triassic of the 

Alps, India, and America. With these two exceptions 

the Meekoceratidae are characteristic of the Lower 

Triassic of western America, Siberia, India, and the 

ancient Mediterranean.

Frech 86 proposed to abandon altogether the family 

Meekoceratidae and the genus Meekoceras, dividing

« Waagen, W., Fossils from the Ceratite formation: India Oeol. Survey Mem., 

Palaeontologia Indica, 13th ser., Salt Range fossils, vol. 2, p. 236,1895.

so Frech, Fritz, Die Dyas: Lethaea geognostica, Teil 1, Das Palaeozoicum, Band 2, 

Lief. 4, p. 630, 1902.

the species assigned to this group between Prionolobus 

Ophiceras, and Aspidites. But this arrangement is 

not in accordance with the rules of priority nor with the 

relationships of the species concerned.

Genus MEEKOCERAS Hyatt

1879. Meekoceras. Hyatt, in White, Fossils of the Jura-Trias 

of southeastern Idaho: U. S. Geol. and Geog. Survey 

Terr. Bull., vol. 5, p. 111.

1880. Meekoceras. Hyatt, in White, Triassic fossils of southeastern Idaho: U. S. Geol. and Geog. Survey Terr. 

Twelfth Ann. Kept., pt. 1, p. 112.

1882. Meekoceras (part). Mojsisovics, Die Cephalopoden der 

Mediterranen Trias-provinz: K.-k. geol. Reichsanstalt 

Wien Abh., Band 10, p. 213.

1886. Meekoceras (part). Mojsisovics, Arktische Triasfaunen: 

Acad. imp. sci. St.-P<§tersbourg Me"m., 7th ser. 

vol. 33, No. 6, p. 79.

1895- Meekoceras. Waagen, Fossils from the Ceratite formation: India Geol. Survey Mem., Palaeontologia Indica, 

13th ser., Salt Range fossils, vol. 2, p. 236.

1895. Meekoceras. Diener, Triadische Cephalopodenfaunen der 

ostsibirischen Ktistenprovinz: Com. g6ol. [St.-Pe'tersbourg] Mem., vol. 14, No. 3, p. 46.

1897. Meekoceras. Diener, Cephalopoda of the Lower Trias: 

India Geol. Survey Mem., Palaeontologia Indica, 

15th ser., Himalayan fossils, vol. 2, pt. 1, p. 126.

1900. Arctoceras. Hyatt, Cephalopoda, in Zittel, K. A. von, 

Textbook of palaeontology (translated by C. R. 

Eastman), p. 559.

1903. Meekoceras. Kittl, Die Cephalopoden der oberen 

Werfener Schichter von Mu6 in Dalmatied: K.-k. 

geol. Reichsanstalt Wien Abh., Band 20, Heft 1, 

p. 69.

1904. Meekoceras. Smith, The comparative stratigraphy of 

the marine Trias of western America: California 

Acad. Sci. Proc., 3d ser., vol. 1, p. 367.

1905. Meekoceras. Hyatt and Smith, The Triassic cephalopod

genera of America: U. S. Geol. Survey Prof. Paper 40,

p. 140. 

1909. Meekoceras. Krafft and Diener, Lower Triassic

Cephalopoda from Spiti, Malla Johar, and Byans:

India Geol. Survey Mem., Palaeontologia Indica, 15th

ser., vol. 6, Mem. 1, p. 16. 

1911. Meekoceras. Arthaber, Die Trias von Albanien: Beitr.

Palaontologie Oesterr.-Ungarns u. des Orients, Band

24, p. 243.

1913. Meekoceras. Diener, Triassic faunae of Kashmir: India 

Geol. Survey Mem., Palaeontologia Indica, new ser., 

vol. 5, Mem. 1, p. 25.

1914. Meekoceras. Smith, The Middle Triassic marine invertebrate faunas of North America: U. S. Geol. Survey 

Prof. Paper 83, p. 77.

1922. Meekoceras. Welter, Die Ammoniten der Unteren Trias 

von Timor: Palaeontologie von Timor,' Lief. 11, Abh. 

19, p. 126.

1927. Meekoceras. Yehara, The Lower Triassic cephalopod and 

bivalve fauna of Shikoku: Japanese Jour. Geology and 

Geography, vol. 5, No. 4, p. 153.

1929. Meekoceras. Mathews, The Lower Triassic cephalopod 

fauna of the Fort Douglas area, Utah: Walker Mus. 

Mem., vol. 1, No. 1, p. 6.

Not 1895. Meekoceras. Diener, Cephalopoda of the Muschelkalk: India Geol. Survey, Palaeontologia Indica, 15th 

ser., Himalayan fossils, vol. 2, pt. 2, p. 40.
55

Type: Meekoceras gracilitatis White. 87

Form compressed, discoidal, involute or evolute, 

sides flattened; venter narrow, either flattened or 

rounded, no keels nor furrows; umbilicus narrow or 

wide. Body chamber short. Surface smooth or ornamented with lateral folds; no tubercles, spines, or 

spiral ridges. Septa ceratitic, with rounded entire 

saddles and serrated lobes. The external lobe is short 

and. divided by a siphonal saddle; the two lateral 

lobes are longer1 , and there is an auxiliary series present 

in most forms, consisting either of a single lobe (serrated or goniatitic) or of a series of denticulations, 

some of which may be partly individualized into lobes. 

The internal septa consist of a divided antisiphonal 

lobe, flanked by a single lateral, although in some 

specimens there may be internal auxiliaries.

Perhaps no other genus of ammonites has been so 

variously treated as Meekoceras, for the reason that it 

is very variable and also because in the first description 

no type was expressly given, and three species, differing 

in essential respects, were simultaneously described 

"Meekoceras" aplanatum White, M. mushbachanum 

White, and M. gracilitatis White, in the order given. 

But in the diagnosis of the genus Hyatt first mentions 

M. gracilitatis. Thus, according to usage, either 

"M." aplanatum or M. gracilitatis might be chosen as 

the type. Of these M. gracilitatis alone agrees with the 

generic diagnosis, for it has the fourth lobe as an 

auxiliary series of denticulations and does not have a 

distinct saddle between this lobe and the umbilical 

suture. Also "Meekoceras" aplanatum is now classed 

under Flemingites, as it has all the characters of that 

genus, including the strong spiral lines on the outer 

shell.

Besides the three species mentioned, Hyatt also 

included in his generic diagnosis previously described 

species that have since been assigned to Balatonites, 

Hunyarites, Xenaspis, and Celtites, which clearly have 

no relationship to the typical members of the genus. 

The writer regards all forms that agree with M. mushbachanum or M. gracilitatis as belonging to Meekoceras 

in the broader sense.

Mojsisovics 88 was the next to treat of this genus, in 

which he included a number of forms now assigned to 

Proptychites and Beyrichites, thus giving Meekoceras an 

unwarranted extension beyond the limits assigned by 

Hyatt. In a later paper Mojsisovics 89 still further extended the genus in one direction to take in forms now 

assigned to Pledenstroemia but limited it on the other 

to involute forms. All evolute, open-coiled forms

« White, C. A., Fossils of the Jura-Trias of southeastern Idaho: U. S. Geol. and 

Gcoi,'. Survey Terr. Bull., vol. 5, p. Ill, 1879; Triassic fossils of southeastern Idaho: 

U. S. Ocol. and Ocog. Survey Terr. Twelfth Ann. Kept., pt. 1, p. 112, pi. 31, figs. 

2 n-d, ISSO.

»3 Mojsisovics, E. von, Die Ccphalopoden dor Mediterranen Triasprovinz: 

IC.-k. gcol. Ilcichsanstalt Wien Abh., Band 10, p. 213, 1882.

|n Mojsisovics, E. von, Arktische Triasfauneu: Acad. imp. sci. St.-P6tersbourg 

MY'in.. 7th sen, vol. 33, No. C, p. 79, 1SSG.

were assigned to Xenodiscus Waagen, although Mojsisovics confessed that this was purely because Xenodiscus 

seemed to be the ancestor of Gymnites.

Meekoceras was next treated by Waagen,90 who regarded M. gracilitatis as the type and placed all other 

kindred but dissimilar forms under different genera, 

thus restricting the genus to narrower limits than was 

intended by Hyatt. The evolute forms without the 

auxiliaries were placed under a new genus, Gyronites, 

which would include most of the forms assigned by 

Mojsisovics to Xenodiscus. Species with a fourth 

lateral lobe followed by an auxiliary series were classed 

under the genus Koninckites Waagen, whereas forms 

in which the auxiliary series is not individualized but 

consists of only a few denticulations were placed under 

Kingites Waagen.

Diener 9I regards Kingites and Koninckites merely as 

subgenera of Meekoceras, and in this conclusion the 

writer agrees with him. In a still later work 92 Diener 

includes also As2)idites Waagen and Beyrichites Waagen 

as subgenera under Meekoceras. But these two types 

are different from any species included by Hyatt under 

the original description, and it seems best to let them 

stand as independent genera. Kingites is now definitely 

discarded, its species going back to Meekoceras.

As thus defined, Meekoceras in the broader sense 

would include all species similar to the typical forms, 

and the species nearest to M. gracilitatis White would 

be classed in Meekoceras in the limited sense.

Examination of the types in the United States National Museum has shown that Meekoceras mushbachanum has all the characters assigned by Waagen 

to Koninckites, and as this species was one of the types 

of Meekoceras all species similar to M. mushbachanum 

are classed in the subgenus Koninckites, under Meekoceras in the broader sense. Clypeoceras (Aspidites] 

and Beyrichites are regarded by the writer as independent genera. .The systematic position of Prionolobus is 

somewhat doubtful, but it should probably be a 

synonym of Meekoceras, though most of its species will 

go to Xenodiscus or Ophiceras.

Frech 93 has recently proposed to drop the family 

Meekoceratidae and the genus Meekoceras, dividing the 

species belonging to that genus between Opliiceras, 

Prionolobus, and Aspidites, although all the genera 

mentioned were described after Meekoceras, which 

was first described in 1879 and described and fully 

illustrated in 1880. Frech's reasons for these changes 

were that Hyatt included in his original description of 

Meekoceras not only the three American species that

M Waagen, W., Fossils from the Ceratite formation: India Oeol. Survey Mem., 

Palacontologia Indica, 13th ser., Salt Range fossils, vol. 2, p. 230, 1895.

" Diener, Carl, Triadische Cephalopodenfauuen der ostsibirischen Ktisteuprovinz: Com. geol. [St.-P6tersbourg] Mem., vol. 14, No. 3, p. 46, 1895.

02 Diener, Carl, Cephalopoda of the Lower Trias: India Oeol. Survey Mem., 

Palaeontologia Indica, 15th ser., Himalayan fossils, vol. 2, pt. 1, p. 126, 1S97.

M Frech, Fritz, Die Dyas: Lethaea geognostica, Teil 1, Das Palaeozoicum, Band 

2, Lief. 4, p. 630, 1902.
56 LOWER TRIASSIC AMMONOIDS OF NORTH AMERICA

differ in certain noteworthy characters but also foreign 

species later assigned to Balatonites, Xenaspis, Hungarites, and Celtites. Of course, it was a mistake to 

include these elements in Meekoceras, but the citation 

of them as species under that genus does not make 

any confusion as to the limits of the group. Three 

American species were fully described and figured, and 

one of the three was certainly the type. 94 The fact 

that later writers have extended the genus Meekoceras 

to take in heterogeneous elements does not invalidate 

it. If any such rule in nomenclature should be accepted almost every genus of ammonites would be 

thrown out and new names substituted.

As thus restricted, Meekoceras is entirely confined to 

the Lower Triassic, in which it is very abundant in 

California, Idaho, India and Siberia.

Meekoceras arthaberi Smith, n. sp.

Plate 32, Figures 26-33

Shell small, involute, laterally compressed, with 

nearly closed umbilicus, flattened sides, angular ventral shoulders and rather broad, flat venter. Surface 

nearly smooth, with only fine growth lines. Septa 

ceratitic, with three well-defined saddles and four serrated lobes, the auxiliary being well developed on the 

umbilical slope. The septa are close set, and the 

lobes are broader than is usual on this genus.

Meekoceras arthaberi is more robust and more narrowly umbilicate than M. gracilitatis. It differs from 

M. boreale Diener, of the Lower Triassic of India, in 

its more flattened whorl and more closely set septa.

Named in honor of Prof. G. von Arthaber, in recognition of his contributions to Triassic paleontology.

Horizon and locality: Rather common in the Lower 

Triassic Meekoceras zone of southeastern Idaho, at 

locality 1, 5 miles southeast of Grays Lake; locality 2, 

Slug Creek, Aspen Mountains, 14 miles east of Soda 

Springs; locality 3, head of Wood Canyon, Aspen 

Mountains, 9 miles east of Soda Springs, associated 

with Meekoceras gracilitatis, M. mushbaclianum, Flemingites russelli, F. aplanatus, Hedenstroemia kossmati, 

Cordillerites angulatus, Lanceolites compactus, Aspenites 

acutus, Ussuria waageni, Pseudosageceras multilobatum, 

and other forms.

Meekoceras cristatum Smith, n. sp.

Plate 33, Figures 15-20; Plate 34, Figures 1-6

Shell large, discoidal, evolute, laterally compressed, 

rather widely umbilicate with rounded umbilical and 

subangular ventral shoulders. Flanks gently arched, 

venter narrow and somewhat flattened. Surface bears 

fine radial ribs that cross the venter, giving it a crenulate or cristate sculpture. Septa ceratitic, with three 

well-defined saddles and four serrated lobes.

9< Alpheus Hyatt told the writer, in June, 1900, that he has always regarded 

Meekoceras gracilitatis as the generic type, as the generic diagnosis shows.

Meekoceras cristatum in early youth is very like M. 

gracilitatis, but the egression of the whorl begins at a 

much earlier stage, and the crenulation of the surface 

sets in early, distinguishing the two species readily. 

It has a greater resemblance to M. sylvanum, from 

which it is distinguished by its much stronger sculpture.

Horizon and locality: Rather rare in the Lower 

Triassic Meekoceras zone of southeastern Idaho, at 

locality 1, 5 miles southeast of Grays Lake; locality 2, 

Slug Creek, Aspen Mountains, 14 miles east of Soda 

Springs; locality 3, head of Wood Canyon, Aspen 

Mountains, 9 miles east of Soda Springs; associated 

with Meekoceras gracilitatis, M. mushbachanum, Flemingites russelli, F. aplanatus, Hedenstroemia kossmati, 

Cordillerites angulatus, Lanceolites compactus, Aspenites 

acutus, Ussuria waageni, Pseudosageceras multilobatum, 

and other forms.

Meekoceras curticostatum Smith, n. sp.

Plate 48, Figures 21-30

Shell rather large, laterally compressed, moderately 

widely umbilicate, discoidal. Whorls narrow, with 

abrupt umbilical shoulders and narrowly rounded 

venter. Surface with somewhat distant lateral ribs 

that run from the umbilicus two-thirds of the distance 

up the flanks. There are about 20 of these ribs to a 

revolution. Septa ceratitic, with four external lobes, 

all serrated, and rounded saddles. The height of the 

last whorl is five-twelfths of the diameter of the shell, 

the width is two-fifths of the height, and the width of 

the umbilicus is somewhat less than one-fourth of the 

diameter of the shell.

Meekoceras curticostatum has some resemblance to 

M. pilatum, with which it is associated, differing in 

the wider umbilicus, more compressed whorls, weaker 

and more numerous ribs. It is not nearly related to 

any other known species.

Horizon and locality: Rather rare in the Lower 

Triassic Columbites zone of Paris Canyon, 1 mile west 

of Paris, Idaho; associated with Columbites parisianus, 

C. spencei, Ophiceras spencei, 0. jacksoni, Pseudharpoceras idahoense, and other forms.

Meekoceras elkoense Smith, n. sp.

Plate 55, Figures 14-16

Shell of moderate size, laterally compressed, involute, 

deeply embracing, narrowly umbilicate, with abrupt 

umbilical shoulders, slightly convex sides, with distinct 

concavity below the sharp ventral angles. Surface 

nearly smooth. Septa ceratitic, with four well-developed external serrated lobes.

The height of the last whorl is more than one-third 

of the diameter of the shell; the width is greater than 

one-half the height; the width of the umbilicus is about 

one-third of the diameter of the shell. The outer whorl 

embraces two-thirds of the inner.
MEEKOCERATIDAE 57

Meekoceras elkoense is most nearly related to M. 

radio sum, differing in its more open umbilicus and 

less embracing whorl, also in the more pronounced 

concavity below the ventral shoulder angles; in septa 

the two species are very similar.

Horizon and locality: Very rare in the Lower Triassic 

Owenites subzone of the Meekoceras zone, at the Phelan 

ranch, month of Cotton wood Canyon, east side of the 

Ruby Range, Elko County, Nov., about 70 miles 

south of Wells; associated with Meekoceras gracilitatis, 

Owenites koeneni, Inyoites oweni, Anasibirites desertorum, Lanceolites bicarinatus, Pseudosageceras multilobatum, and other forms.

Meekoceras gracilitatis White

Plate 12, Figures 1-13; Plate 13, Figures 1-18; Plate 14' 

Figures 1-8; Plate 36, Figures 19-28; Plate 37, Figures 1-7; 

Plate 38, Figures 1-6; Plate 70, Figures 4-7

1879. Meekoceras gracilitatis. White, Fossils of the JuraTrias of southeastern Idaho: U. S. Geol. and Geog. 

Survey Terr. Bull., vol. 5, p. 114.

1880. Meekoceras gracilitatis. White, Triassic fossils of southeastern Idaho: U. S. Geol. and Geog. Survey Terr. 

Twelfth Ann. Kept., pt. 1, p. 115, pi. 31, figs. 2 a-d.

1902. Prionolobus gracilitatis. Frech, Lethaea geognostica, 

Teil 1, Das Palacozoicum, Band 2, Lief. 4, p. 631, 

fig. 2.

1904. Meekoceras gracilitatis. Smith, The comparative stratigraphy of the marine Trias of western America: 

California Acad. Sci. Proc., 3d ser., vol. 1, p. 370, pi. 

42, figs. 1-4; pi. 43, figs. 3, 4.

1905. Meekoceras gracilitatis. Hyatt and Smith, The Triassic 

cephalopod genera of America: U. S. Geol. Survey 

Prof. Paper 40, p. 143, pi. 12, figs. 1-13; pi. 13, figs. 

1-18; pi. 14, figs. 1-8; pi. 70, figs. 4-7.

Shell compressed, involute, discoidal, deeply embracing, outer whorl concealing three-fourths of the 

inner and. being indented to one-third of its height by 

the inner whorl. Umbilicus narrow but open and 

rather shallow, the width being about one-sixth of the 

diameter of the shell. The whorl increases rather 

rapidly in height, the altitude being slightly more than 

twice the breadth of the whorl and half the total diameter. The sides are gently convex, from the abruptly 

rounded umbilical shoulder; the greatest thickness of 

the whorl lies at a point even with the top of the inner 

whorl, thus giving a lenticular appearance to the shell. 

Venter flattened, biangular, with broad flat space and 

sharp abdominal shoulder angles.

Surface ornamented with low folds and radial striae 

of growth, which in age cross the venter in faint corrugations. No true ribs nor spines are ever present.

Septa ceratitic, saddles all rounded and entire, lobes 

all serrated. Ventral short, divided by a broad, shallow siphonal saddle; first lateral broad and deeper; 

second lateral narrow as the ventral; auxiliary series 

consisting of a short, straight row of denticulations 

following the third lateral saddle, forming merely an 

unindividualized. lobe, which, however, is sharply distinguished from the saddle. The inner septa consist 

of a rather short divided antisiphonal lobe, with a 

single lateral.

The young shells are much more involute than mature forms, the umbilicus growing wider with age, and 

the whorls less deeply embracing. The relative width 

of the umbilicus, however, seems to be variable, also 

the abruptness or roundness of the umbilical shoulders. 

Diener 95 thinks that White has confused two species 

in his figures of M. gracilitatis, and that Plate 31, 

Figure 2b, in White's paper represents a different 

species from Figure 2a. But the difference lies rather 

in the drawing than in the original specimens. The 

septa on White's original are as shown in Plate 31, 

Figure 2d, of White's paper, except that the denticulations are not sufficiently strongly marked in the 

drawing, and the innermost saddle is more sharply 

defined from the auxiliary denticulations than in the 

figure. In some unfigured specimens, however, there 

does not seem to be any separation at all of the saddle 

and the auxiliary series. These specimens in all other 

respects seem to belong to M. gracilitatis and were 

probably the cause of the ambiguities in Hyatt's and 

White's descriptions. These forms would fall under 

Waagen's genus Kingites, but they are probably nothing more than individual variations of M. gracilitatis, 

and for the present they are not included in the specific 

diagnosis, for it is essential to establish the exact 

meaning of this species.

M. gracilitatis White is nearly related to M. boreale 

Diener of the Lower Triassic of India and Siberia but 

differs in not having the auxiliary series individualized, 

also in the slightly wider umbilicus. There are, however, in the American Lower Triassic, species with the 

umbilicus as narrow or even narrower than that of M. 

boreale, but on all of them the auxiliary series is unindividualized.

Horizon and locality: Meekoceras gracilitatis White 

was found by Peale in the Lower Triassic Meekoceras zone 

of southeastern Idaho, at two places 5 miles south 

of Grays Lake and about 15 miles a little east of south 

from this lake. Alpheus Hyatt also found this species 

in Wood Canyon, about 9 miles east of Soda Springs, 

Idaho, associated with M. mushbachanum White, 

Pseudosageceras multilobatum Noetling, Flemingites 

russelli Hyatt and Smith, F. aplanatus White, Ussuria 

waageni, and other characteristic species. J. P. Smith 

found M. gracilitatis in the Owenites subzone of the 

Meekoceras zone of Union Wash, near Union Spring, 

east side of Owens Valley, Inyo Range, about 15 miles 

southeast of Independence, Inyo County, Calif., associated with Inyoites oweni, Owenites koeneni, Pseudosageceras multilobatum, and other forms.

95 Diener, Carl, Cephalopoda of the Lower Trias: India Qeol. Survey Mem., 

Palaeontologia Indica, 15th ser., Himalayan fossils, vol. 2, pt. 1, p. 132, 1897.
58 LOWER TRIASS1C AMMONOIDS OF NORTH AMERICA

Meekoceras davisi Mathews

Plate 79, Figures 7, 8

1929. Meekoceras davisi. Mathews, The Lower Triassic cephalopod fauna of the Fort Douglas area, Utah: Walker 

Mus. Mem., vol. 1, No. 1, p. 6, pi. 1, figs. 12-14.

1929. Meekoceras hertleini. Mathews, op. cit., p. 6, pi. 1, figs. 

8-11.

The specific description given below is quoted from 

Mathews:

The form is extremely involute, discoidal, thin, gently compressed laterally; high whorls, completely embracing, and deeply 

indented by the inner volution. The sides are nearly flat, being 

only slightly compressed, and slope from the umbilicus uniformly to the ventral shoulder. The ventral shoulder is sharply 

angular and appears to form a keel due to the narrow channeled venter; the umbilical shoulder is angular. The inner wall 

is vertical. The umbilicus is extremely narrow and deep, being 

only one twenty-second of the diameter of the shell. The 

height of the last whorl is over twice its greatest thickness and 

four-sevenths of its diameter. It is indented to one-half its 

height by the preceding whorl and completely conceals this 

whorl. The distance across the penultimate volution from 

umbilical suture to umbilical suture is five-eighths its involution. The venter is narrow, concave, and smooth. The living 

chamber comprises nearly one-half of the last whorl. The shell 

is very thin and smooth.

The surface is ornamented by a few indistinct, wide, progressive radial folds, which are most prominent near the umbilicus 

and become obsolete three-fourths the distance to the outer 

margin of the side wall.

. The sutures are ceratitic, consisting of a ventral and two 

lateral lobes. The ventral lobe is divided by a notched wedgeshaped siphonal saddle. The lateral prongs are serrated by 

five denticulations. The first and second lateral lobes are 

narrow and serrated. The lateral saddles are all smooth and 

wide.

The first whorl is nearly round and little embracing; the 

second whorl is elliptical with the long axis of the ellipse in the 

plane of the shell. The whorl is embracing. The third and 

remaining whorls possess the adult characters. The shell 

develops rapidly in height after the second volution.

^Horizon and locality: Lower Anasibirites bed, Pinecrest 

formation, Cephalopod Gulch, Fort Douglas Military Reservation, Utah.

Meekoceras micromphalus Smith, n. sp.

Plate 49, Figures 5-11

Shell rather small, with very narrow umbilicus, 

whorls strongly compressed laterally, and narrowly 

rounded venter. Surface with very weak radial folds. 

Septa with rounded saddles, a small ventral lobe divided into two short branches, a rather large first 

lateral, a smaller second lateral, and an auxiliary lobe 

not individualized but consisting of a long series of 

denticulations. The height of the last whorl is greater 

than half the diameter of the shell; the width is threesevenths of the height; the width of the umbilicus is 

less than one-seventh of the diameter of the shell.

The outer whorl embraces nearly all of the inner and 

is impressed by that whorl to nearly one-third of its 

height.

Meekoceras micromphalus is very closely related to 

M. keyserlingi Mojsisovics, of the Lower Triassic 

Olenek beds of Siberia, differing only in the slightly 

wider umbilicus. The Arctic species was chosen by 

Waagen 96 as the type of his new Kingites, which is no 

longer recognized as distinct from Meekoceras, to 

which both M. keyserlingi and M. micromphalus are 

now assigned.

Horizon and locality: Rather rare in the Lower 

Triassic zone of Columbites, at Paris Canyon, 1 mile 

west of Paris, Idaho; associated with Meekoceras 

curticostatum, M. pilatum, Columbites parisianus, C. 

spencei, Pseudharpoceras idahoense, and other forms.

Meekoceras patelliforme Smith, n. sp.

Plate 28, Figures 21-27; Plate 52, Figures 9-11

Shell small, laterally compressed, involute, deeply 

embracing, with flattened sides, nearly parallel, and 

rounded venter without distinct shoulders. Surface 

nearly smooth, with fine striae of growth. Septa 

distinctly ceratitic, with entire saddles and four serrated lobes, the auxiliary being well individualized, the 

siphonal and laterals long and rather narrow.

The height of the last whorl is two-fifths of the diameter of the shell; the width is one-third of the height; 

the width of the umbilicus is one-fifth of the diameter 

of the shell. The outer whorl embraces two-thirds of 

the inner and is indented to one-fourth of the height.

Meekoceras patelliforme is very like M. sanctorum of 

the Columbites zone of Idaho but differs in its slightly 

wider umbilicus, more nearly parallel sides, more 

rounded venter, and longer lobes.

Horizon and locality: Rather common in the 

Meekoceras zone of southeastern Idaho, at locality 1, 

5 miles east of Grays Lake; locality 2, Slug Creek, 

Aspen Mountains, 14 miles east of Soda Springs; at 

locality 3, head of .Wood Canyon, Aspen Mountains, 

9 miles east of Soda Springs; at the mouth of Paris 

Canyon, 1 mile west of Paris. The species is associated 

with Meekoceras gracilitatis, M. mushbachanum, Flemingites russelli, Hedenstroemia kossmati, Cordillerites 

angulatus, Lanceolites compactus, Aspenites acutus, 

Pseudosageceras multilobatum, Ussuria waageni, Paranannites aspenensis, and other forms.

Also occurs in the Owenites subzone, of Union Wash, 

Inyo Mountains, 15 miles southeast-of Independence, 

Inyo County, Calif., associated with Owenites koeneni, 

Inyoites oweni, Anasibirites desertorum, and other forms.

96 Waagen, W., Fossils from the Ceratite formation: India Geol. Survey Mem., 

Palaeontologia Indica, 13th ser., Salt Range fossils, vol. 2, p. 230,1895.
MEEKOCERATIDAE 59

Meekoceras pilatum Hyatt and Smith

Plate 63, Figures 7-13

1905. Meekoceras pilatum. Hyatt and Smith, The Triassic 

cephalopod genera of America: U. S. Geol. Survey 

Prof. Paper 40, p. 144, pi. 63, figs. 3-9.

Form involute, laterally compressed; whorls high, 

with flattened sides broadly rounded venter, without 

distinct abdominal shoulders. Umbilical shoulders 

abrupt and somewhat angular. Whorls deeply embracing, and deeply indented by the inner volutions. 

The height of the whorl is slightly less than half the 

total diameter of the shell, and the width is half the 

height. The whorl is indented to one-fourth its height 

by the preceding volution. The width of the umbilicus 

is one-fourth of the total diameter of the shell.

The surface of both shell and cast is ornamented 

with coarse radial ribs, which run from the umbilicus 

straight up the flanks and become obsolete on the 

shoulders. In addition to these ribs there are the 

usual curved striae of growth, showing only to the 

surface of the shell.

The septa are of the usual Meekoceras type, with the 

saddles all rounded and entire and the lobes all serrated. The external lobe is short and narrow, divided 

by a small siphonal saddle; the first lateral lobe is 

broad and deep; the second lateral narrow and long; 

the auxiliary lobe is not individualized but resembles 

that of Meekoceras gracilitatis.

Horizon and locality: In the Lower Triassic Columbites /one, 1 mile west of Paris, Idaho, locality 1981, 

United States Geological Survey, associated with 

Columbites parisianus, Pseudosageceras multilobatum, 

Ophiceras jacksoni, Ophiceras spencei, and other forms; 

collected by R. S. Spence.

Meekoceras radiosum Waagen

Plate 51, Figures 1-4

1895. Meekoceras radiosum. Waagen, Fossils from the Ceratite 

formation: India Geol. Survey Mem., Palaeontologia 

Indica, 13th ser., Salt Range fossils, vol. 2, p. 257, 

pi. 36, figs. 2a-cl.

1909. Meekoceras radiosum. KrafFt and Diener, Lower Triassic 

Cephalopoda from Spiti, Malla Johar, and Byans: 

India Geol. Survey Mem., Palaeontologia Indica, 15th 

ser., vol. 16, No. 1, p. 34.

1911. Meekoceras radios-urn. Arthaber, Die Trias von Albanien: 

Beitr. Palaontologie Oesterr.-Ungarns u. des Orients, 

Band 24, p. 246, pi. 21, fig. 14.

Shell rather small, laterally compressed, very 

involute, with high, slightly convex flanks and rather 

distinct concavity below the narrow and biangular 

venter. Whorls very deeply embracing. Surface 

with fine radial ribs, suggesting kinship with Anasibirites. Septa with four external serrated lobes, the 

auxiliary being distinctly individualized. 

67664 32 5

Meekoceras radiosum is more robust than either 

M. gracilitatis or M. boreale. It is more closely 

related to M. elkoense but differs in its greater involution, less compressed whorl, stronger sculpture, and. 

the distinct fourth lobe.

Horizon and locality: Rather common in the 

Owenites subzone of the Meekoceras zone of Union 

Wash, Inyo Mountains, about 15 miles southeast of 

Independence, Inyo County, Calif.; associated with 

Meekoceras gracilitatis, Owenites koeneni, Inyoites oweni, 

Lanceolites bicarinatus, Aspenites acutus, Sturia compressa, Pseudosageceras multilobatum, Anasibirites 

desertorum, and other forms.

It was first described from the Ceratite sandstone 

of the Salt Range of India. Arthaber has also described it from the Columbites zone of Albania. It is 

therefore a very widely distributed species and not 

confined to a narrow horizon of the Lower Triassic.

Meekoceras sanctorum Smith, n. sp.

Plate 49, Figures 1-4

Shell rather small, laterally compressed, narrowly 

umbilicate, with a subangular roof-shaped venter. 

Surface almost smooth, with very faint radial folds. 

Septa with four external lobes and three saddles. 

The height of the last whorl is half the diameter of the 

shell; the width is two-fifths of the height; the last 

whorl embraces nearly all of the inner and is impressed 

to one-sixth of its height.

Meekoceras sanctorum is very closely related to 

M. ajfine Mojsisovics 97 of the Lower Triassic Olenek 

beds of Siberia, differing only in being slightly more 

robust. This species adds another link to the connection between the Columbites fauna of Idaho and the 

Olenek fauna of Siberia.

Horizon and locality: Rather rare in the Lower 

Triassic Columbites zone of Paris Canyon, 1 mile west 

of Paris, Idaho; associated with Columbites parisianus, 

C. spencei, Ophiceras spencei, Meekoceras pilatum, M. 

micromphalus, M. curticostatum, Pseudharpoceras 

idahoense, Tirolites cf. seminudus, Celtites ursensis, and 

other forms.

Meekoceras sylvanum Smith, n. sp.

Plate 33, Figures 1-14

Shell large, discoidal, laterally compressed, rather 

widely umbilicate, with flattened sides, narrow biangular venter, and subangular ventral shoulders. Surface 

with faint radial folds, especially on the body chamber. 

Septa ceratitic, with four external serrated lobes and 

three rounded saddles.

Meekoceras sylvanum is very closely related to M. 

gracilitatis, from which it differs in the wider umbilicus;

07 Mojsisovics, E. von, Arktische Triasfaunen: Acad. imp. sci. St.-P6tersbourg 

Mfim., 7th ser., vol. 33, No. 6, p. 86, pi. 11, fig. 17, 1886.
60 LOWER TBIASSIC AMMONOIDS OF NORTH AMERICA

it also greatly resembles M. hodgsoni Diener, of the 

Lower Triassic of the Himalayas, differing in the 

greater thickness of the whorl. From Meekoceras

o _

vercherei Waagen, from the Lower Triassic of the Salt 

Range of India, it differs in lacking the long auxiliary 

series of lobes; from its near kinsman Meekoceras disciforme Krafft and Diener, of the Lower Triassic of 

the Himalayas, it differs in its greater involution. 

Its greatest kinship, however, is with M. gracilitatis, of 

which it would have been considered a variety if it 

were not for the constantly much greater evolution, 

which persists down even to the end of the larval stage. 

Horizon and locality: Rather common in the Lower 

Triassic Meekoceras zone of southeastern Idaho, at 

locality 3, Wood Canyon, Aspen Mountains, 9 miles 

east of Soda Springs; at locality 1, 5 miles east of 

Grays Lake; at locality 2, Slug Creek, Aspen Mountains, 14 miles east of Soda Springs; associated with 

Meekoceras mushbachanum, M. gracilitatis, Flemingites 

russelli, I-Iedenstroemia kossmati, Cordillerites angulatus, Pseudosageceras multilobatum, Lanceolites compactus, and other forms.

Subgenus KONINCKITES Waagen

1895. Koninckites. Waagen, Fossils from the Ceratite formation: India Geol. Survey Mem., Palaeontologia Indica, 

13th ser., Salt Range fossils, vol. 2, p. 258.

1895. Koninckites. Diener, Triadische Cephalopodenfaunen 

der ostsibirischen Ktistenprovinz: Com. geol. [St.- 

Pe"tersbourg] Me"m., vol. 14, No. 3, p. 53.

1896. Koninckites. Toula, Eine Muschelkalkfauna am Golfe 

von Ismid in Kleinasien: Beitr. Palaontologie Oesterr.- 

TJngarns u. des Orients, Band 10, p. 177.

1897. Koninckites. Diener, Cephalopoda of the Lower Trias: 

India Geol. Survey Mem., Palaeontologia Indica, 15th 

ser., Himalayan fossils, vol. 2, pt. 1, p. 139.

1902. Aspidites (part). Frech, Lethaea geognostica, Teil 1, 

Das Palaeozoicum, Band 2, Lief. 4, p. 637.

1904. Koninckites. Smith, Comparative stratigraphy of the 

marine Trias of western America: California Acad. 

Sci. Proc., 3d ser., vol. 1, p. 375.

1905. Koninckites. Hyatt and Smith, The Triassic cephalopod 

genera of America: U. S. Geol. Survey Prof. Paper 40, 

p. 148.

1909. Koninckites. Krafft and Diener, Lower Triassic Cephalopoda from Spiti, Mall a Johar, and Byans: India 

Geol. Survey Mem., Palaeontologia Indica, 15th ser., 

vol. 6, Mem. 1, p. 64.

Type: Koninckites r-etustus Waa.gen.98

Evolute, discoidal, laterally compressed, narrow 

venter, either flattened or rounded. Sides flattened 

and entire form not robust. Umbilicus wider than in 

typical members of Meekoceras s. s. and lateral ornamentation commonly stronger, in the form of coarse 

radial ribs or folds.

Septa as in Meekoceras s. s., but the auxiliary lobe is 

individualized, followed by a distinct auxiliary saddle, 

and this by a series of denticulations, forming a second

98 Waagen, W., Fossils from the Ceratite formation: India Geol. Survey Mem., 

Palaeontologia Indica, 13th ser., Salt Range fossils, vol. 2, p. 261, pi. 27, figs. 4, 5.

auxiliary lobe on the umbilical shoulder. This subgenus embraces a number of species from the Lower 

Triassic of the Salt Range, the Himalayas, Ussuri. 

Bay, and the mouth of the Olenek River, in northern 

Siberia. Waagen did not know that Meekoceras 

mushbachanum White possessed all the essential characters of Koninckites, for the figure of the septa of 

that species is not exact. But as this is the case, and 

as M. mushbachanum was one of the three species 

given as typical members of Meekoceras, this group of 

species, characterized by the greater evolution, the 

more rugose shell, and the fourth lobe with the auxiliary denticulations, is regarded merely as a subgenus. 

There are in the American Triassic, both in Idaho and 

California, several species that will fall into this 

division.

Frech " proposes to drop Koninckites, referring the 

species described by Waagen under that name to 

Aspidites. Although this reference is, no doubt, correct for some of those species, it is not correct for the 

type, nor for the species like the type, one of which is 

Meekoceras (Koninckites} mushbachanum.

Meekoceras (Koninckites) evansi Smith, n. sp.

Plate 35, Figures 1-3; Plate 36, Figures 1-18

Shell large, robust, moderately evolute, discoidal, 

with rounded umbilical shoulders, slightly convex 

sides, and gently rounded venter. Surface with fine 

radial folds and fine growth lines. Septa ceratitic, 

with entire saddles, and serrated lobes. The ventral 

lobe is divided into two rather short branches; the first 

lateral is large, the second lateral is smaller, and following this there is a short but distinct series of auxiliary 

lobes, decreasing in size and complexity toward the 

umbilicus.

The height of the last whorl is slightly less than half 

the diameter of the shell, and the width is less than 

three-fourths of the height. The width of the umbilicus is one-fourth of the diameter of the shell.

In youth, up to a diameter of 7 millimeters, the shell 

is in the Lecanites stage, thick set, robust, low whorled. 

It then becomes flattened, the whorl becomes higher 

and the umbilicus relatively narrower; this transitional 

stage persists up to a diameter of about 40 millimeters, 

when the width of the umbilicus is about one-fifth of 

the diameter of the shell. At a diameter of about 50 

millimeters the fine lateral folds or ribs begin to develop, and the umbilicus becomes proportionately 

wider. The young stages are therefore very unlike the 

mature form and could easily be taken for different 

species.

Meekoceras evansi is very closely related to M. 

mushbachanum, differing in its greater involution, 

greater compression and weaker sculpture. It also

w Frech, F., Lethaea geognostica, Teil 1, Das Palaeozoicum, Band 2, Lief. 4, 

p. 637, 1902.
MEEKOCERATIDAE 61

resembles "Koninckites" veiustus Waagen 1 but is less 

robust, and does not have the auxiliary series of lobes 

so sharply defined. It is distinguished by its large 

size from all other American species of Meekoceras 

except M. mushbachanum. Chambered specimens as 

much as 72 millimeters in diameter have been found, 

which would indicate that the species reached the 

diameter of more than 100 millimeters.

Named in honor of Dr. H. M. Evans, who assisted 

in collecting this fauna.

Horizon and locality: Rather common in the Lower 

Triassic Meekoceras zone, of southeastern Idaho, at 

locality 1, 5 miles southeast of Grays Lake; locality 2, 

Slug Creek, 14 miles east of Soda Springs; locality 3, 

head of Wood Canyon, Aspen Mountains, 9 miles east 

of Soda Springs; locality 5, 1 mile east of Hot Springs, 

at the north end of Bear Lake; associated with Meekoceras gracilitatis, M. mushbachanum, Flemingites russelli, F. aplanatus, Hedenstroemia kossmati, Cordillerites angulatus, Lanceolites compactus, Ussuria waageni, 

Pseudosageceras multilobatum, and other forms.

Meekoceras (Koninckites) mushbachanum White

Plate 15, Figures 1-9; Plate 16, Figures 1-3; Plate 18, Figures 

1-7; Plate 38, Figure 1; Plate 59, Figures 17-21; Plate 70, 

Figures 8-10; Plate 74, Figures 1-23; Plate 75, Figures 1-6; 

Plate 76, Figures 1-3

1879. Meekoceras mushbachanum. White, Fossils of the JuraTrias of southeastern Idaho: U. S. Geol. and Geog. 

Survey Terr. Bull., vol. 5, p. 113.

1880. Meekoceras muslibaclianum. White, Triassic fossils of 

southeastern Idaho: U. S. Geol. an'cl Geog. Survey 

Terr. Twelfth Ann. Kept., pt. 1, p. 114, pi. 32, fig. 1 a-d.

1902. Prionolobus muslibachanus. Frecli, Lethaea geognostica, 

Toil 1, Das Palaeozoicum, Band 2, Lief. 4, p. 631, 

fig. c.

1904. Meekoceras mushbachanum. Smith, Comparative stratigraphy of the marine Trias of western America: California Acad. Sci. Proc., 3d set1 ., vol. 1, p. 376, pi. 41, 

figs. 1-3; pi. 43, figs. 1, 2.

1905. Meekoceras (Koninckites) mushbachanum. Hyatt and 

Smith, The Triassic cephalopod genera of America: 

U. S. Geol. Survey Prof. Paper 40, p. 149, pi. 15, 

figs. 1-9; pi. 16, figs. 1-3; pi. 18, figs. 1-7; pi. 70, 

figs. 8-10.

1914. Meekoceras mushbachanum. Smith, The Middle Triassic 

marine invertebrate faunas of North America: U. S. 

Geol. Survey Prof. Paper 83, p. 77, pi. 72, figs. 1, 2; 

pi. 73, figs. 1-6; pi. 74, figs. 1-23.

Compressed, involute, discoidal, whorls rather 

deeply embracing, covering nearly three-fifths of the 

inner volution and being indented to one-fourth of its 

height by it. Umbilicus wide, shallow; umbilical 

shoulders abruptly rounded. Sides more flattened 

than in M. gracilitatis White, gently convex up to the 

abruptly rounded narrow venter. Height of whorl 

twice its breadth and nearly half the entire diameter. 

Width of umbilicus nearly one-fourth of the entire

1 Wnngon, \V., Fossils from the Ceratite formation: India Geol. Survey Mem., 

Pnlncontologialiiclica, 13th sor., Salt Range fossils, vol. 2, p. 261, pi. 27, figs. 4, 5,1895.

diameter of the shell. Greatest breadth of whorl at a 

point halfway between base and venter.

Surface ornamented with sharp cross striae, slightly 

curved, and faint low folds, especially in age.

Septa ceratitic; saddles all rounded and entire, lobes 

all serrated. Ventral lobe divided by a broad, shallow 

siphonal saddle, the two divisions being serrated with 

about five denticulations; the first lateral is somewhat 

deeper and broader; the second lateral about half as 

deep as the first, and about two-thirds its width; the 

first auxiliary is small, shallow, provided with several 

denticulations; then follows a distinct auxiliary saddle, 

with a row of denticulations between that and the 

umbilicus. The internal septa consist of a moderately 

long antisiphonal lobe, and a single lateral.

Horizon and locality: Meekoceras (Koninckites] 

mushbachanum White is rather common in the Lower 

Triassic Meekoceras zone of southeastern Idaho, 

where it was found at a place 5 miles southeast of 

Grays Lake and at another place 15 miles a little 

east of south from that lake. Alpheus Hyatt also 

found it at Wood Canyon, about 9 miles east of Soda 

Springs, Idaho. J. P. Smith found it in the Lower 

Triassic Meekoceras zone of the Inyo Range, in Union 

Wash, near Union Spring, east side of Owens Valley, 

about 15 miles southeast of Independence, Inyo 

County, Calif. In both Idaho and California it was 

associated with Meekoceras gracilitatis, Pseudosageceras 

multilobatum, and many other forms characteristic of 

the Lower Triassic of the regions around the Pacific.

Meekoceras (Koninckites) mushbachanum White, var. 

corrugatum Smith, n. var.

Plate 38, Figure 1

Shell large, evolute, widely umbilicate, laterally 

compressed, with flattened sides, and rounded venter. 

Surface bears coarse radial ribs that run straight up 

the flanks and become nearly obsolete on the venter. 

Septa and shape of the whorl exactly like those of 

Meekoceras mushbachanum. It also greatly resembles 

Meekoceras costatum Oeberg, as figured and described 

by Mojsisovics, 2 but differs in the straighter ribs. It 

is undoubtedly merely a variant from the typical form, 

with no stratigraphic significance, and is here figured 

and named in order to form a complete record of the 

group of so-called "Arctoceras,' } the discrimination of 

which has caused so much unnecessary confusion in 

the classification of the Meekoceratidae.

Horizon and locality: Rather common in the Lower 

Triassic Meekoceras zone of southeastern'Idaho, at 

locality 1, 5 miles east of Grays Lake; at locality 3, 

Wood Canyon, Aspen Mountains, 9 miles east of 

Soda Springs; at locality 5, 1 mile east of Hot Springs, 

north end of Bear Lake; at all these localities in the

2 Mojsisovics, E. von, Arktische Triasfaunen: Acad. imp. sci. St.-P6tersbourg 

Mem., 7th ser., p. 36, pi. 7, fig. 3, 188C.
62 LOWER TRIASSIC AMMONOIDS OF NORTH AMERICA

same beds and faunal association as the typical form 

of the species.

Meekoceras (Koninckites) newberryi Smith, n. sp.

Plate 53, Figures 1-4

Shell large, evolute, laterally compressed; whorls 

high, with narrow but rounded venter. Umbilicus 

wide, with abruptly rounded shoulders. Surface 

nearly smooth, with very gentle folds and weak 

growth lines. Septa ceratitic, with rounded saddles 

and serrated lobes, of which the auxiliary consists of a 

series of small individuals, decreasing in size toward 

the umbilicus.

The height of the last whorl is two-fifths of the 

diameter of the shell; the width is half the height. 

The width of the umbilicus is one-third of the diameter of the shell. The last whorl embraces twofifths of the inner and is indented by it to one-fourth 

of the height.

Meekoceras newberryi is closely related to M. 

mushbachanum, differing in its greater compression 

and weaker sculpture.

Named in honor of J. S. Newberry.

Horizon and locality: Rather common in the 

Owenites subzone of the Meekoceras zone of Union 

Wash, Inyo Mountains, about 15 miles southeast of 

Independence, Inyo County, Calif.; associated with: 

Meekoceras gracilitatis, Owenites koeneni, Inyoites 

oweni, Lanceolites bicarinatus, Aspenites acutus, Anasibirites desertorum, Pseudosageceras multilobatum, and 

other forms.

Meekoceras (Koninckites) strongi Smith, n. sp.

Plate 52, Figures 12-17

Shell large, discoidal, evolute, widely umbilicate, 

with slow increase in height of whorl and rapid increase in diameter of the umbilicus. Whorls with 

flattened sides, gently rounded umbilical shoulders, 

and narrow arched venter, without ventral shoulders. 

Septa with rounded entire saddles, a short divided 

ventral lobe, large first lateral, somewhat smaller. 

second lateral, a well-individualized auxiliary, followed by a short series of auxiliaries not individualized, 

all the lobes serrated. The internal septa show a 

large antisipbonal, flanked by a much smaller lateral 

lobe. The septa are very like those of Meekoceras 

mushbachanum.

The height of the whorl is somewhat less than half 

the diameter of the shell, the width of the whorl is 

less than half the height; the outer whorl embraces 

two-thirds of the inner and is indented by it to twosevenths of the height. The width of the umbilicus 

is less than one-third of the diameter of the shell.

Meekoceras strongi is rather closely related to M. 

mushbachanum, differing in its greater compression 

and narrower venter, gentler slope of the umbilical

shoulders, and greater convergence of the flanks toward the venter.

Named in honor of Mr. A. M. Strong, who assisted 

in collecting this fauna.

Horizon and locality: Rather rare in the Lower 

Triassic Owenites subzone of the Meekoceras zone, of 

Union Wash, Inyo Mountains, about 15 miles southeast 

of Independence, Inyo County, Calif.; associated with 

Meekoceras gracilitatis, <Pseudosageceras multilobatum, 

Owenites koeneni, Inyoites oweni, Anasibirites desertorum, 

Lanceolites bicarinatus, Sturia compressa, and other 

forms.

Meekoceras (Koninckites) tuberculatum Smith, n. sp.

Plate 50, Figures 1-4

Shell very large, discoidal, evolute, laterally compressed, widely umbilicate, with sides flattened and 

venter rounded. Surface with very weak folds, and 

fine umbilical nodes or tubercles, 14 to a revolution. 

Septa ceratitic, with three broadly rounded saddles 

and four strongly serrated lobes.

The height of the last whorl is three-sevenths of the 

diameter of the shell, and the width is slightly less than 

half the height. The outer whorl embraces half the 

inner and is indented by it to one-fourth of the height. 

The width of the umbilicus is one-fourth of the diameter of the shell. Imperfect specimens up to a diameter 

of 150 millimeters were found that lack the body chamber, which would add more than 50 millimeters to the 

diameter.

Meekoceras tuberculatum has some resemblance to 

M. fulguratum Waagen, of the Lower Triassic of the 

Salt Range in India, but differs in possession of the 

row of umbilical nodes. It also resembles "Cei'atites" 

oebergi Mojsisovics,3 of the Lower Triassic of Svalbard, 

but differs in its broader lobes.

Horizon and locality: Veiy rare in the Owenites 

subzone of the Meekoceras zone of Union Wash, Inyo 

Mountains, 15 miles southeast of Independence, Inyo 

County, Calif.; associated with Meekoceras gracilitatis, 

Inyoites oweni, Owenites koeneni, Lanceolites bicarinatus, Anasibirites desertorum, A. noetlingi, Pseudosageceras multilobatum, Juvenites dieneri, and other

forms.

Genus CLYPEOCERAS Smith

1895. Aspidites. Waagen, Fossils from the Ceratite formation: 

India Geol. Survey Mem., Palaeontologia Indica, 

13th ser., Salt Range fossils, vol. 2, p. 215.

1897. Aspidites. Diener, Cephalopoda of the Lower Trias: 

India Geol. Survey Mem., Palaeontologia Indica, 

15th ser., Himalayan fossils, vol. 2, pt. 1, p. 145.

1902. Aspidites (part). Frech, Lethaeageognostica, Teil 1, Das 

Palaeozoicum, Band 2, Lief. 4, p. 637.

1903. Aspidites. Arthaber, Neue Funde in den Werfener 

Schichten mid im Muschelkalke des siidlichen Bakony: 

Resultate der wissenchaftlichen Erforschung des 

Balatonsees, Band 1, Teil 1, p. 18.

3 Mojsisovics, E. von, op. cit., p. 33, pi. 7, figs. 5, 6; pi. 8, figs. 1, 3.
MEEKOCERATIDAE 63

1905. Aspidites. Hyatt and Smith, The Triassic ceplialopod 

genera of America: U. S. Geol. Survey Prof. Paper 

40, p. 152.

1913. Clypeoceras. Smith, Ammonoidea, in Zittel, K. A. von, 

Textbook of palaeontology (translated by C. R. 

Eastman), p. 645.

1914. Aspidites. Arthaber, Die Trias von Bithynien (Anatolien): Beitr. Palaontologie Oesterr.-Ungarns u. des 

Orients, Band 27, p. 113.

Not 1876. Aspidites. Peters, K. Akad. Wiss. Berlin Monats-. 

ber., p. 914. (A snake.)

Type: Aspidites superlus Waagen. 4

Laterally compressed, discoidal, involute; whorls 

deeply embracing and deeply indented by the inner 

whorls, increasing rapidly in height. Sides only 

slightly convex, sloping up to the rather narrow 

venter, which may be either angular or rounded but 

never provided with keels or furrows. Umbilicus 

usually narrow. Surface smooth or ornamented with 

radial striae and folds. No ribs visible at any stage 

of growth. Body chamber short, as in most discoidal 

shells.

Septa distinctly ceratitic, with rounded saddles and 

serrated lobes. The external lobe is divided into two 

branches by a siphonal saddle which may itself be 

serrated but not to the extent of forming adventitious 

lobes. The first and second laterals are large and 

deep, and the denticulations may run high up on the 

sides of the saddles. The auxiliary series is very long 

and complicated, consisting of several denticulations 

united into a broad auxiliary lobe, followed by a 

number of irregular lobes of greater or less size, not 

individualized. The saddles are usually long and 

narrower than the lobes. The internal septa consist 

of a divided antisiphonal lobe, with a principal internal 

lateral and an auxiliary series inside the umbilical 

suture.

This genus greatly resembles the subgenus Koninckites but differs in the greater involution and the 

greater complexity of the auxiliary series, both external 

and internal; it may A^ery likely have developed out 

of Koninckites. Another genus with which it may be 

compared is Clypites, which, however, has adventitious 

lobes and also has the auxiliary series much simpler; 

also Clypites is usually more involute than Clypeoceras, 

although this character alone would not be sufficient 

for separation.

Clypeoceras has been found in the Lower Triassic of 

the Salt Range and the Himalayas in India and in 

Hungary, Timor, and Albania; Alpheus Hyatt found 

it in the Meekoceras zone of Aspen Ridge, near Soda 

Springs, in southeastern Idaho, and J. P. Smith found 

it in the same zone in the Inyo Mountains of Inyo

4 Waagen, W., Fossils from the Ceratite formation: India Geol. Survey Mem., 

Palneontologia Inclica, 13th ser., Salt Range fossils, vol. 2, p. 218, pi. 23; pi. 24, fig. 1, 

n-b,1805

County, Calif., in both places associated with Meekoceras gracilitatis White. It is therefore a world-wide 

Lower Triassic genus.

Clypeoceras hooveri Hyatt and Smith

Plate 17, Figures 1-12

1905. Aspidites hooveri. Hyatt and Smith, The Triassic cephalopod genera of America: U. S. Geol. Survey Prof. 

Paper 40, p. 153, pi. 17, figs. 1-12.

Form compressed, discoidal, involute, deeply embracing, inner whorls almost completely concealed by 

the outer and indenting the outer to nearly half its 

height. Umbilicus narrow, the umbilical shoulders of 

the succeeding whorls being so gently rounded and 

meeting each other at so nearly the same angle that 

the umbilicus makes a deep and craterlike conical 

depression. Sides gently convex, from the craterlike walls of the umbilicus to the rounded and rather 

narrow venter. Greatest breadth of the whorl at a 

point halfway from base to venter.

Surface ornamented with fine cross striae, which 

are visible only in the few places where the shell is 

preserved. The body chamber appears to have been 

two-thirds of the last revolution.

Septa ceratitic, but some of the saddles have become 

slightly ammonitic. The external lobe is broad and 

divided into the broad branches by a shallow siphonal 

saddle, which is digitate, but not to the extent of 

forming adventitious lobes.

The first lateral lobe is equally broad and twice as 

deep; the second lateral lobe is about two-thirds the 

depth of the first. Then comes the auxiliary series, 

consisting of a small, somewhat individualized, first 

auxiliary, followed by a long, irregular series of denticulations, making more or less distinct lobes and 

saddles but smaller than0 the first.

The first lateral saddle is long, narrow, and denticulate to the apex on the upper side; the second is similar 

in shape but longer and entire; the third, which 

separates the second lateral lobe from the auxiliary 

series, is shallow, broad, and denticulate all around. 

The septa are more highly specialized than those of 

any other known species of Clypeoceras, being more 

like those of Proptychites ammonoides Waagen.5 But 

in Clypeoceras hooveri the saddles are narrower, the 

first lateral saddle denticulate only on the upper side, 

and the secondary lobes in the auxiliary series much 

smaller and more distinct. Also the first and second 

lateral lobes are not rounded at the end but square, 

and the denticulations are fewer. Proptychites ammonoides is quite robust, the whorl being nearly twice as 

thick proportionally as in Clypeoceras hooveri.

6 Idem, p. 171, pi. 17, figs. a-c.
64

Dimensions of Clypeoceras hooveri

Type specimen Millimeters 

Diameter-______________________________ 124

Height of last whorl..__________________ 60

Height of last whorl from the preceding_____ 34

Width of last whorl ____________________ 22

Width of umbilicus-_-_---------_-___-____ 14

Involution ______________________________ 26

A smaller specimen

Diameter ___-__-____'_______-_-_--_______ 21

Height of last \vhorL_____________________ 9

Height of last whorl from the preceding.____ 7

Width of last whorl._____________________ 5

Width of umbilicus_-____----___--__---___ 6

Involution._ __-_________-__-___--.______ 2

The smaller specimen was broken so as to expose the 

inner whorls, and at the diameter of 5 millimeters 

showed a distinct Lecanites stage, similar to that of 

Meekoceras gracilitatis. No other proof is needed of 

the relationship and derivation of this genus.

Horizon and locality: Clypeoceras hooveri was found 

by J. P. Smith in the Lower Triassic Owenites subzone 

of the Meekoceras zone, of the Inyo Range, east side of 

Owens Valley, in Union Wash, about 1% miles east of 

Union Spring and 15 miles southeast of Independence, 

Inyo County, Calif. It was associated with Meekoceras gracilitatis White, Meekoceras mushbachanum 

White, Flemingites aplanatus White, and many other 

forms.

Clypeoceras muthianum (Krafft)

Plate 27, Figures 1-7

1909. Aspidites midhianus. Krafft, in Krafft and Diener, 

Lower Triassic Cephalopoda from Spiti, Malla Johar, 

and Byans: India Ceol. Survey Mem., Palaeontologia 

Indica, 15th ser., vol. 6, Mem. 1, p. 59, pi. 6, fig. 5; 

pi. 15, figs. 1, 2.

Shell rather large, high whorled, narrowly umbilicate 

laterally compressed, with narrow and gently rounded 

venter. Surface smooth, with only fine growth lines. 

Septa ceratitic, with rounded entire saddles and very 

strongly serrated lobes. The external lobe is divided 

into two short and rather broad branches; the saddle 

between the external and first lateral lobe is long and 

strongly constricted toward the base. The first lateral 

lobe is long and broad, with very numerous and long 

serrations; the second lateral is about half as large; 

then follows a long auxiliary series, decreasing in size 

and complexity toward the umbilicus.

The largest specimen found had a diameter of 70 

millimeters; in a typical specimen the height of the last 

whorl is slightly less than half of the diameter of the 

shell; the width is slightly less than half the height; 

and the width of the umbilicus is one-seventh of the 

diameter of the shell.

The American specimens agree perfectly with 

"Aspidites" muthianus from the Hedenstroemia beds of 

the Himalayas, as figured by Krafft and Diener in

the work cited above, and the faunal association is 

the same in the two regions. It is not surprising to 

find generalized forms resembling each other in widely 

separated regions, but Clypeoceras muthianum is a 

highly specialized type with may peculiar characters 

that would attract the attention of the systematist at 

once. However, Clypeoceras muthianum does not 

stand alone in showing connection between India and 

western America during this epoch; Xenodiscus nivalis, 

Pseudosageceras multilobatum, and Owenites egrediens 

appear to occur on both sides of the Pacific Ocean, and 

many species of Meekoceras are so closely related that 

separation is difficult or even arbitrary.

Horizon and locality: Rather rare in the Lower 

Triassic Meekoceras zone (Pseudosageceras multilobatum subzone) at the head of Wood Canyon (locality 3), 

Aspen Mountains, 9 miles east of Soda Springs, Idaho; 

associated with Meekoceras gracilitatis, M. mushbachanum, Flemingites russelli, F. cirratus, F. aplanatus, 

Hedenstroemia kossmati, Cordillerites angulatus, Lanceolites compactus, Pseudosageceras multilobatum, Aspenit es acutus, and other forms.

The species was first described from the Hedenstroemia beds of India, in very much the same faunal 

association, with Meekoceras, Hedenstroemia, Flemingites, Pseudosageceras, and other forms very closely 

related to American species.

Clypeoceras pusillum Smith, n. sp.

Plate 51, Figures 11-13

Shell small, involute, laterally compressed, with 

flattened sides, narrow umbilicus, and narrow flattened 

venter bordered by blunt angles. Surface smooth. 

Septa ceratitic, with rounded saddles and serrated lobes 

of which there are a small external, two larger laterals, 

and a long auxiliary series, reducing in size toward the 

umbilicus.

Dimensions of the type specimen of Clypeoceras pusillum

Millimeters 

Diameter._____________________________ 20

Height of last whorl.____________________ 11

Height of last whorl from the preceding.., 5. 5 

Width of last whorl__________-,_-__--____ 4

Width of umbilicus__-_----_---__-------- 2. 5

Clypeoceras pusillum is closely related to "Aspidites " 

eurasiaticus Frech, as figured by Arthaber, 6 but it 

differs from the Hungarian species in its much smaller 

size and much longer and more complex auxiliary 

series of lobes.

Horizon and locality: Very rare in the Owenites 

subzone of the Meekoceras zone of Union Wash, Inyo 

Mountains, 15 miles southeast of Independence, Inyo 

County, Calif.; associated with Meekoceras gracilitatis, 

Clypeoceras hooveri, Anasibirites noetlingi, A. desers Arthaber, O. von, Neue Funde in den Werfener Schichten und im Muschelkalke 

des siidlichen Bakony: Resultate der wissenschaftlichen Erforschung des Balatonsees, Band 1, Teil 1, p. 18, pi. 1, figs. 1 a-c, 1903.
MEEKOCERATIDAE 65

torum, Inyoites oweni, Owenites koeneni, Lanceolites 

compactus, Sturia compressa, Pseudosageceras multilobatum, and other forms.

Genus DAGNOCERAS Arthaber

1911. Dagnoceras. Arthaber, Die Trias von Albanien: Beitr' 

Paliiontologie Oesterr.-TJngarns u. cles Orients, Band 

24, p. 24.0.

Type: Dagnoceras komanum Arthaber. 7

Arthaber in his work cited describes a group of 

meekoceran forms, from the Columbites beds, under 

the name Dagnoceras, family Arctoceratinae, without 

citation of a type. The first species mentioned in the 

diagnosis is D. komanum Arthaber, which therefore 

automatically becomes the type, although it is by no 

means the most characteristic form.

All the species listed are moderately involute, 

rather robust, and with narrow venters and very 

simple serrated lobes.

Arthaber overlooks the fact that "Ardoceras" is 

merely Meekoceras of the group of M. mushbachanum 

and that the so-called family Arctoceratinae does not 

exist.

In the Meekoceras zone of Idaho there are four 

species that belong to this group, Dagnoceras, characterized by the thick flanks and narrow venters and by 

having the young extremely robust and with the strong 

collar ribs suggestive of Paratirolites. It is not known 

that the Albanian species possess the latter character, 

for no young specimens were figured and described.

The writer regards Dagnoceras as a valid group, 

more nearly related to Anasibirites than to Meekoceras.

The American species referred to Dagnoceras are D. 

bridgesi Smith, D. bonnevillense Smith, D. haydeni 

Smith, and D. pealei Smith, all from' the Pseudosageceras multilobatum subzone of the Meekoceras zone 

of southeastern Idaho. Of these D. haydeni is the 

most characteristic and has the generic characters in 

most marked degree. It is rather probable that 

Arthaber's species assigned to Dagnoceras are not all 

congeneric, but this could be decided only by an 

ontogenic study of them, which was not possible with 

the material available. Dagnoceras terbunicum Arthaber is the only Albanian species with any close 

resemblance to the American and should have been 

chosen as the type, as it is well represented in the 

fauna described.

The writer regards this group as a parallel development with Meekoceras from Xenodiscus, and from the 

subgenus Paratirolites or some kindred form. The 

young stages of the American species are entirely 

unlike those of Meekoceras and are fairly consistently 

uniform. Therefore they are assigned to the genus 

Dagnoceras, in spite of the doubt as to the unity of

7 Artlmbor, O. von, Die Trias von Albanien: Beitr. PalJiontologie Oesterr.- 

TJngarns u. clos Orients, Band 24, p. 242, pi. 21, figs. 11 a-c.

the Albanian species and of the doubt as to what is the 

type.

Horizon and locality: Rather common in the Lower 

Triassic Columbites zone of Albania; rather rare in the 

Lower Triassic Meekoceras zone of southeastern Idaho.

Dagnoceras bonnevillense Smith, n. sp.

Plate 29, Figures 9-23

Shell small, involute, strongly compressed laterally, 

arched sides, and narrow venter, with blunt marginal 

angles but no ventral furrow. Surface smooth. 

Septa ceratitic, with four external serrated lobes, of 

which the auxiliary is not individualized but consists 

of a few serrations.

The height of the last whorl is three-fourths of the 

diameter of the shell, the width is more than onethird of the height; the width of the umbilicus is 

greater than one-fourth of the diameter of the shell.

Dagnoceras bonnevillense resembles D. haydeni but is 

less evolute, is more gibbous and less egredient and has 

less sharp ventral keels but no ventral furrow.

Horizon and locality: Rare in the Lower Triassic 

Meekoceras zone of southeastern Idaho, at locality 3, 

Wood Canyon, Aspen Mountains, 9 miles east of Soda 

Springs; associated with Meekoceras gracilitatis, M. 

mushbachanum, Flemingites russelli, Hedenstroemia 

kossmati, Aspenites acutus, Cordillerites angulatus, 

Lanceolites compactus, Pseudosageceras multilobatum, 

Paranannites aspenensis, Juvenites kraffti, and other

forms.

Dagnoceras bridgesi Smith, n. sp.

Plate 31, Figures 1-7

Shell small, involute, laterally compressed, narrowly 

umbilicate, deeply embracing. Whorls flattened, with 

greatest breadth at the umbilical shoulder, tapering 

gently to the narrow biangular venter. Ventral 

furrow pronounced, founded by rather sharp keels. 

Surface nearly smooth. Septa ceratitic, with the 

fourth or auxiliary lobe consisting of an obscure row 

of denticulations, not individualized.

Dagnoceras bridgesi differs from D. haydeni in its 

more compressed and less evolving whorl and narrower umbilicus. It is thicker than D. pealei, with 

deeper umbilicus and steeper umbilical walls.

Named in memory of James Bridges, who assisted 

in collecting this fauna and working out the stratigraphy of the Lower Triassic of Idaho.

Horizon and locality: Rare in the Lower Triassic 

Meekoceras zone of southeastern Idaho, at locality 1, 

5 miles southeast of Grays Lake; associated with 

Meekoceras gracilitatis, M. mushbachanum, Flemingites 

russelli, Hedenstroemia kossmati, Aspenites acutus, 

Cordillerites angulatus, Lanceolites compactus, Xenodiscus intermontanus, Pseudosageceras multilobatum, 

and other forms.
66 LOWER TRIASSIC AMMONOIDS OF NORTH AMERICA

Dagnoceras haydeni Smith, n. sp.

Plate 29, Figures 1-8

Shell small, laterally compressed, rather widely 

umbilicate; high whorl with greatest thickness at the 

umbilicus, sloping to the very narrow biangular venter. 

The umbilicus is wide, and the whorl decidedly 

egredient. In youth the whorl is coronate, with distinct collar ribs like those of Anasibirites.

The septa are ceratitic, with rounded entire saddles 

and three external lobes, being thus simpler than those 

of Meekoceras. The length of the body chamber is 

uncertain but appears to be less than a revolution.

The height of the last whorl is less than half the 

diameter of the shell; the width is half the height; 

the width of the umbilicus is one-fourth of the diameter 

of the shell. The outer whorl embraces three-fifths 

of the inner and is indented by it to one-third of the 

height.

Dagnoceras haydeni is closely related to D. terbunicum 

Arthaber from Albania, agreeing in the narrow biangular venter, in the thickening at the umbilicus, and 

in the possession of only three external lobes, which 

are very similar on the two species. It differs from 

D. terbunicum in the wider and more egredient umbilicus and in the thicker whorl.

Horizon and locality: Rather rare in the Lower 

Triassic Meekoceras zone of southeastern Idaho, at 

locality 1, 5 miles southeast of Grays Lake, at locality 3, 

Wood Canyon, Aspen Mountains, 9 miles east of Soda 

Springs; associated with Meekoceras mushbachanum, 

M. gracilitatis, Flemingites russelli, Hedenstroemia 

kossmati, Lanceolites compactus, Cordillerites angulatus, Aspenites acutus, Pseudosageceras multilobatum, 

and other forms.

Dagnoceras pealei Smith, n. sp.

Plate 29, Figures 24-37

Shell small, laterally compressed, involute, narrowly 

Limbilicate, deeply embracing. Sides flattened, converging gently to the narrow biangular venter, with 

narrow ventral furrow. Surface nearly smooth, with 

fine transverse striae. Septa ceratitic, with four external serrated lobes, of which the auxiliary is broken 

up into a series of denticulations like that supposed to 

be characteristic of "Prionolobus." 

 Dagnoceras pealei is thinner and less egredient than 

the other American members of this group. It is 

very similar to Xenodiscus schmidti Mojsisovics,8 and 

especially to Figures 11 a-c of Mojsisovics's plate, 

which Waagen 9 names as a new species, "Gyronites" 

mojsisovicsi Waagen. It differs from the Arctic species 

chiefly in the less sharp ventral keels and the nar8 Mojsisovics, E. von, Die Arktische Triasfaunen: Acad. imp. sci. St.-P6tersbourg M6m., 7th ser., vol. 33, No. 6, p. 77, pi. 11, figs. 7-11, 1886.

0 Waagen, W., Fossils from the Ceratite formation: India Oeol. Survey Mem., 

Palaeontologia Indica, 13th ser., Salt Range fossils, vol. 2, p. 290, 1895.

rower ventral space between the angles. In septa 

and shape the two agree perfectly.

Named in honor of A-. C. Peale, whose work on the 

geology of southeastern Idaho has been invaluable to 

later workers in that region.

Horizon and locality: Rare in the Lower Triassic 

Meekoceras zone of southeastern Idaho, at locality 3, 

Wood Canyon, Aspen Mountains, 9 miles east of 

Soda Springs; associated with Meekoceras gracilitatis, 

M. mushbachanum, Flemingites russelli, Hedenstroemia 

kossmati, Ussuria waageni, Aspenites acutus, Cordillerites angulatus, Lanceolites compactus, Paranannites 

aspenensis, Juvenites kraffti, Prenkites depressus, Pseudosageceras multilobatum, Ophiceras dieneri, and other 

forms.

Genus KASHMIRITES Diener

1913. Kashmirites. Diener, Triassic faunae of Kashmir: India

Geol. Survey Mem., Palaeontologia Indica, new ser.

vol. 5, Mem. 1, p. 33. 

1922. Kashmirites. Welter, Die Ammoniten der Unteren Trias

von Timor: Palaeontologie von Timor, Lief. 11, Abh.

19, p. 120.

1929. Kashmirites. Mathews, The Lower Triassic cephalopod 

fauna of the Fort Douglas area, Utah: Walker Mus. 

Mem., vol. 1, No. 1, p. 36. 

1929. Wasatchites. Mathews, op. cit., p. 40.

Type: Group of "Celtites" armatus Waagen.

Shell robust, moderately evolute, rather widely 

umbilicate; cross section subquadratic, with height 

approximately equal to the breadth. Sculpture consisting of sharp, undivided ribs that begin in nodes 

on the umbilical shoulders, run straight up the flanks, 

and cross the venter with considerable reduction in 

size, and without a forward-bending sinus. Septa 

ceratitic, with rounded saddles; there is a divided 

ventral lobe, a very large first lateral, a smaller second 

lateral, and a small auxiliary outside the umbilical 

suture; the internal septa show a long antisiphonal 

lobe (divided?) flanked by a small lateral.

The body chamber is said by Welter to be about 

three-quarters of a revolution in length.

Diener, in describing this genus, stated that it was 

a derivative of Xenodiscus and a near relative or 

Sibirites ( Anasibirites}. The writer would go still 

further and state that Kashmirites is derived from 

the Paratirolites group of Xenodiscus and that it was 

the ancestor of Anasibirites, giving a much needed 

link between the Xenodiscidae and that branch of the 

Meekoceratidae. The young of those species of 

Kashmirites that have been studied resemble closely 

the adults of Paratirolites.

Kashmirites, so far as known, is restricted to 

the Flemingites or Hedenstroemia beds of India; to the 

Owenites zone of Timor (which lies just between the 

Pseudosageceras multilobatum and Anasibirites zones); 

and to the Anasibirites subzone of the Meekoceras 

zone of Utah. The genus is therefore a successor to
MEEKOCERATIDAE 67

Genodiscus, of which it is supposed to be a descendant, 

and a predecessor of Anasibirites, of which it is probably 

the ancestor.

Ma thews has described in the paper cited above 

several species of Kashmirites from the Anasibirites 

subzone of Utah, along with the supposedly new genus 

Wasatchites, which, however, agrees in all essentials 

with typical Kashmirites and is listed in the synonymy 

of that genus.

Kashmirites meeki (Mathews)

Plate 81, Figures 1, 2

1929. Wasatchites meeki. Mathews, The Lower Triassic cephalopod fauna of the Fort Douglas area, Utah: Walker 

Mus. Mem., vol. 1, No. 1, p. 41, pi. 7, figs. 1-3; pi. 8, 

figs. 11-14.

The specific description is quoted from the paper 

by Mathews, cited above.

Tliis form is involute, discoidal, rugose, laterally compressed; 

whorls high, deeply embracing, and well indented by the preceding volution. The sides are nearly flat, sloping rapidly 

from the umbilical shoulder to the outer margin. The ventral 

shoulder is square. The umbilical shoulder is square, possessing well-defined, somewhat elongated, sharp nodes, with 

the elongation crossing the whorl. The umbilicus is narrow 

and deep, being one-fourth the diameter of the shell. The 

height of the last whorl is a little greater than its greatest 

thickness and one-half its diameter. It is indented to one-third 

its height by the penultimate volution and conceals threefourths of this volution. The distance across the penultimate 

volution from suture to suture is greater than the involution. 

The venter is slightly arched and highly sculptured. The 

living chamber is fully one-half the last volution. The shell is 

thick. The cross section of the last whorl is trapezoidal.

The surface is ornamented with distinct nodes at the umbilical 

shoulder, which give rise to indistinct, flexuous, radial ribs 

that become somewhat prominent as they cross the ventral 

shoulder. They cross the venter in a low arc. The surface 

sculpture shows on the preceding volutions. The entire surface is covered with extremely fine, flexuous costae.

The sutures are ceratitic. The ventral lobe is divided by a 

moderately deep siphonal saddle. The lateral prongs are 

deeply serrated. The first lateral lobe is broad and moderately 

long, the second is short and broad; both are serrated. The 

lateral saddles are broad and smooth. The sutures are slightly 

incised.

Horizon and locality-: Upper Anasibirites bed, Pinecrest formation, Baffle Ridge, Fort Douglas Military Reservation, 

Utah.

Kashmirites perrini (Mathews)

Plate 81, Figures 6-8

1929. Wasatchites perrini. Mathews, The Lower Triassic 

cephalopod fauna of the Fort Douglas area, Utah: 

Walker Mus. Mem., vol. 1, No. 1, p. 40.

1929. Wasatchites magnus. Mathews, op. cit., p. 41, pi. 11, 

figs. 1, 2.

This species was chosen by Mathews as the type of 

a supposedly new genus, " Wasatchites/' but as the 

characters of the type agree in all essentials with 

those of Kashmirites, it is placed under that genus, 

and Wasatchites is put in synonymy.

The specific diagnosis is quoted from the work of 

Mathews, cited above.

This form is involute, discoidal, rugose, laterally compressed; 

whorls high, moderately embracing, and well indented by the 

penultimate volution. The sides are nearly flat and slope 

rapidly from the umbilical to the ventral shoulder. The ventral 

shoulder is angular. The umbilical shoulder is angular, possessing well-developed, long, sharp nodes. The inner wall is 

nearly vertical. The umbilicus is moderately wide and deep; 

it is about one-third the diameter of the shell and three times 

its own depth. (The measurements were taken from the depression between the nodes.) The height of the last whorl is 

nearly twice its greatest thickness and less than one-half its 

diameter. It is indented to nearly one-fourth its height by the 

preceding volution and conceals over half of this volution. The 

distance across the penultimate volution from suture to suture 

is nearly twice the involution. The venter is slightly arched, 

broad, and highly sculptured. The living chamber is fully 

one-half the last whorl. The cross section of the last whorl is 

broadly trapezoidal. The shell is very thick and appears 

to consist of an inner and an outer layer.

The surface is ornamented with broad, prominent, nearly 

straight radial ribs, which bend forward'near the ventral shoulder where they become enlarged, forming a distinct nodose 

character. They originate in groups of three on the highly 

developed nodes or spines of the umbilical shoulder and after 

traversing the side wall cross the venter in a straight line. The 

ornamentation shows on all of the whorls. The sutures are 

ceratitic. The ventral lobe is narrow, occupying one-half the 

venter, and is divided by a wide, short siphonal saddle. The 

lateral prongs are serrated. The first lateral lobe is long and 

narrow; the second is short, narrow, and may ride the umbilical 

nodes; both lobes are deeply serrated. The auxiliary lobe is 

wide, deep, and crosses the inner wall in a retrogressive manner. 

The third lateral saddle is broad, shallow, and rides the umbilical shoulder. The sutures are not incised. The early whorls 

are rugose, about as broad as high, and the adult characters 

show on the fourth volution.

This species is somewhat similar to Ceratites S'librobustus Mojsisovics. It has a square outline, more highly developed sculpture; the umbilical nodes are much more intensely developed; 

the venter is flat and the sutures are less ceratitic.

Horizon and locality: Upper Anasibirites bed, Piuecrest formation, Baffle Ridge, Fort Douglas Military Reservation, Utah.

Kashmirites resseri Mathews

Plate 81, Figures 9, 10

1929. Kashmirites resseri. Mathews, The Lower Triassic cephalopod fauna of the Fort Douglas area, Utah: Walker 

Mus. Mem., vol. 1, No. 1, p. 38, pi. 8, figs. 4-7.

The specific diagnosis of Kashmirites resseri is quoted 

from the paper of Mathews, cited above.

This form is involute, discoidal, thin, laterally compressed; 

whorls high, deeply embracing, and well indented by the preceding volution. The sides are slightly convex and slope rapidly from the umbilical to the ventral shoulder. The ventral 

shoulder is square. The umbilical shoulder is slightly rounded. 

The inner wall is wide and nearly vertical. The umbilicus is 

wide and moderately deep, being one-fifth the diameter of the 

shell. The height of the last whorl is one and one-half times 

its width and one-half the diameter of the shell. It is indented 

to one-third its height by the preceding volution and conceals 

three-fourths of this volution. The distance across the penultimate volution from suture to suture nearly equals the involution. The venter is flat and moderately wide. The cross sec-
68 LOWER TRIASSIC AMMONOIDS OF NORTH AMERICA

tion of the last whorl is nearly trapezoidal. The surface is 

ornamented by a few widely spaced, straight radial ribs, which 

become indistinct near the ventral shoulder. These cross the 

venter in a straight line. The cross section of the first whorl 

is ellipsoidal with the long axis of the ellipse transverse to the 

plane of the shell; the second whorl is ellipsoidal with the long 

axis of the ellipse in the plane of the shell; the third whorl takes 

on the characteristics of the adult.

This species has many characteristics like Goniodiscus and 

may eventually be assigned to that genus. However, the 

sculpture on the side walls is more distinct; the cross section of 

the whorl is trapezoidal, and the sutures are like those of 

Kashmirites.

Horizon and locality: Pinecrest formation, Baffle Ridge, Fort 

Douglas Military Reservation, Utah.

Kashmirites seerleyi (Mathews)

Plate 81, Figures 11, 12

1929. Keyserlingites seerleyi. Mathews, The Lower Triassic 

cephalopod fauna of the Fort Douglas area, Utah: 

Walker Mus. Mem., vol. 1, No. 1, p. 39, pi. 8, figs. 8-10.

This species was described under Keyserlingites 

Hyatt but clearly is a member of Kashmirites. The 

specific diagnosis is quoted from Mathews's paper, 

cited above.

The shell is involute, moderately embracing, discoidal, thick, 

rugose; whorls moderately high, embracing, and slightly 

indented by the preceding volution. The sides are well rounded 

and grade into the shoulders, forming a wide arc. The venter 

is rounded, grading into the flanks without forming distinct 

shoulders. The umbilical shoulder is rounded; the inner wall 

sloping. The umbilicus is wide and deep. The height of the 

last whorl is a little more than its greatest thickness and less 

than one-third its diameter. It is indented to more than onethird its height by the inner volution and conceals nearly half 

of this volution. The distance across the penultimate volution 

from suture to suture is one and one-half times its involution. 

The whorls slowly increase in height. The cross section of the 

last whorl is broadly ellipsoidal.

The surface is ornamented by la.rge, well-defined, slightly 

flexuous radial ribs, which originate in prominent nodes on the 

umbilical shoulder. Four ribs originate from one node. These 

ribs cross the venter in nearly a straight line, becoming somewhat enlarged at the ventral shoulder. The inner wall is plain, 

not being marked by either ribs or costae. The umbilical 

nodes show on the preceding volutions, becoming less sharp 

and more elongated on the inner whorls.

The sutures are ceratitic. The ventral lobe is long, narrow, 

and divided by a deep, narrow siphonal saddle, which is notched 

at its base. The lateral prongs are denticulated. The first 

lateral is long, narrow, and deeply serrated; the second is broad, 

short, and deeply serrated. The saddles are wide, deep, and 

smooth. The first lateral crosses a part of the venter. The 

suture crosses the inner wall in nearly a straight line.

This species quickly develops from its early to its adult stages. 

The adult characters show on the third volution and remain 

constant thereafter.

This species is very similar to Ceratites robustus Mojsisovics, 

but the long axis of the ellipsoidal cross section is in the plane 

of the whorl; the whorls are more evenly spiral, and four ribs 

originate in a single node. The species is not common.

Horizon and locality: Upper Anasibirites beds, Pinecrest 

formation, Cephalopod Gulch, Fort Douglas Military Reservation, Utah.

Kashmirites subarmatus Diener

1913. Kashmirites subarmatus. Diener, Triassic faunae of 

Kashmir: India Geol. Survey Mem., Palaeontologia 

Indica, new ser., vol. 5, Mem. 1, p. 36, pi. 5, figs. 2, 3.

1922. Kashmirites subarmatus. Welter, Die Ammoniteii der 

Unteren Trias von Timor: Palaeontologie von Timor, 

Lief. 11, Abh. 19, p. 121, pi. 164, figs. 6-8.

1929. Kashmirites subarmatus. Mathews, The Lower Triassic 

cephalopod fauna of the Fort Douglas area, Utah: 

Walker Mus. Mem., vol. 1, No. 1, p. 36, pi. 7, figs. 

40-45.

The specific description is quoted by Mathews from 

Diener's work, cited above.

In its general shape, involution, and in the outlines of the 

cross section our species agrees fairly well with K. armatus. 

The umbilicus is impressed less deeply than in K. blaschkei. 

Umbilical margin acute, siphonal margin obtusely rounded. 

Greatest transverse diameter corresponding to the umbilical 

edge.

It is especially in some of the inner nuclei that the siphonal 

area is arched more distinctly than in the full-grown individuals. 

Lateral parts flat.

Sculpture consisting of single radial ribs, which originate in 

the umbilical edge and run in a straight direction toward the 

siphonal margin, where they are slightly turned forward and 

rise occasionally into indistinct tubercles. Some ribs are also 

elevated above the general level at the place where they originate 

near the umbilical edge. In the inner nuclei the ribs attain 

their greatest strength in the umbilical region and become 

gradually obsolete before reaching the siphonal margin, but 

in adult individuals the majority of ribs are of equal strength 

during their entire extent. The siphonal area is not smooth 

but crossed by the ribs symmetrically from either side. The 

external ribs are, however, considerably inferior in strength to 

the lateral ones.

The sculpture and this is the chief difference from the 

ornamentation noticed in K. armatus is very irregular, not 

only in different specimens, but often in the same individual, 

according to different stages of growth. In young specimens, 

as a rule, the ribs are less numerous and, consequently, arranged 

at greater distances than in full-grown individuals. * * * 

At the commencement of the last volution the number of ribs 

is very small, not larger proportionately than in the nucleus 

mentioned above.

The ribs are stout and of equal strength throughout. In the 

remaining portion of this whorl the ribs are crowded. * * *

In the anterior region adjoining the aperture the ribs again 

become less numerous and stout and are elevated considerably 

along the siphonal and umbilical margins.

Dimensions. The measurements of my largest specimen 

are as follows:

Millimeters

Diameter of the shelL_-----_----_-_------ 51

Diameter of the umbilicus---.------.------ 21

Height of the last volution.___--__-__-__-_ 16

Thickness of the last volution_____________ 18

Sutures. The sutural line is well preserved in the specimen 

illustrated in Plate 5, Figure 3, especially in the last septa. 

Lobes elongated and narrow. Principal lateral lobe with three 

distinct denticulations in its base. Two lateral lobes and saddles and a small auxiliary lobe outside the umbilical suture. 

Siphonal and principal lateral saddles of nearly equal size. 

Second lateral saddle considerably smaller.
69

Mathews adds the following comment:

The ribs of the Utah specimens are more strongly developed 

near the umbilical shoulder than on Diener's type, but the other 

characters are practically identical. Therefore, it is safe to refer 

the specimens to this species.

Horizon and locality: Pinecrest formation, Pinecrest Ridge, 

Fort Douglas Military Reservation, Utah.

Kashmirites wasatchensis Mathews

Plate 81, Figures 3-5

1929. Kashmirites ivasatchensis. Mathews, The Lower Triassic cephalopod fauna of the Fort Douglas area, Utah: 

Walker Mus. Mem., vol. 1, No. 1, p. 37, pi. 6, figs. 

26-28.

1929. Kashmirites thornei. Mathews, op. cit., p. 38, pi. 6, figs. 

22-25.

1.929. Kashmirites gilberti. Mathews, op. cit., p. 38, pi. 7, figs. 

4-9.

1929. Wasatchites quadratus. Mathews, op. cit., p. 42, pi. 7, 

figs. 23-25.

This common and variable species has been described 

by Mathews under a variety of names. The specific 

description is quoted from his diagnosis of Kashmirites 

wasatchensis, in the work cited above.

Involute, discoidal, thick, robust, laterally compressed; whorl 

high, slightly embracing, and indented by the preceding volution. Sides flat and slope gently from the umbilical to the 

ventral shoulder. Shoulders square. Umbilicus wide and very 

deep. It is three-eighths the diameter of the shell and three 

times its own depth. Inner wall is wide and vertical. Height 

of the last whorl is less than one-half the diameter of the shell 

and a little greater than its greatest thickness. It is indented 

to one-third its height by the preceding volution and conceals 

nearly one-half this volution. Distance across the penultimate 

volution from suture to suture is greater than the involution. 

Venter is nearly flat and wide. Cross section of the last whorl 

is trapezoidal. Shell is very thick.

Surface is ornamented by coarse, flat ribs, which form nodes 

on the umbilical and ventral shoulders. The ribs cross the 

venter in nearly a straight line. Nodes show on the preceding 

volutions.

Sutures are ceratitic. The two lateral lobes are serrated. 

The first lateral is long and narrow; the second is broad, shallow, 

and rides the ribs. The ventral lobe is broad and divided by 

a deep siphonal saddle. The lateral prongs are denticulate.

Remarks: This species is similar to Kashmirites subarmatus 

Diener, but the cross section of the last whorl is less quadrate, 

the ribs are less distinct, the involution is greater and the sutures 

are ceratitic. It is similar to Kashmirites acutangulatus Welter; 

but the ribs are less distinct, the nodes are better defined on the 

umbilical shoulder, and the ventral lobe is serrated.

Horizon and locality: Upper Anasibirites beds, Pinecrest 

formation, Cephalopod Gulch, Fort Douglas Military Reservation, Utah.

Genus ANASIBIRITES Mojsisovics

1895. Sibirites. Waagen, Fossils of the Ceratite formation: 

India Geol. Survey Mem., Palaeontologia Indica, 

13th ser., Salt Range fossils, vol. 2, p. 104.

1896. Anasibirites. Mojsisovics, Beitrage zur Kenntniss der 

obertriadischen Cephalopodenfaunen des Himalaya: 

K. Akad. Wiss. Wien, Math.-nat. Klasse, Denkschr., 

Band 63, p. 615.

1899. Anasibirites. Mojsisovics, Upper Triassic cephalopod 

faunae of the Himalaya: India Geol. Survey Mem., 

Palaeontologia Indica, 15th ser., Himalayan fossils, 

vol. 3, pt. 1, p. 49.

1905. Sibirites. Hyatt and Smith, The Triassic cephalopod 

genera of America: U. S. Geol. Survey Prof. Paper 40. 

p. 48.

1909. Sibirites. Krafft and Diener, Lower Triassic Cephalopoda from Spiti, Malla Johar, and Byans: India Geol. 

Survey Mem., Palaeontologia Indica, 15th ser., vol. 6, 

Mem. 1, p. 124.

1911. Pseudosibirites. Arthaber, Die Trias von Albanien: 

Beitr. Paliiontologie Oesterr.-Ungarns u. des Orients, 

Band 24, p. 254.

1913. Sibirites. Diener, Triassic faunae of Kashmir: India 

Geol. Survey Mem., Palaeontologia Indica, new ser., 

vol. 5, Mem. 1, p. 31.

1914. Anasibirites. Arthaber, Die Trias von Bithynien

(Anatolien): Beitr. Palaontologie Oesterr.-Ungarns u.

des Orients, Band 27, p. 178. 

1922. Anasibirites. Welter, Die Ammoniten der Unteren Trias

von Timor: Palaeontologie von Timor, Lief. 11, Abh.

19, p. 138. 

1927. Sibirites. Yehara, The Lower Triassic cephalopod and

bivalve fauna of Shikoku: Japanese Jour. Geology and

Geography, vol. 5, No. 4, p. 167. 

1929. Anasibirites. Mathews, The Lower Triassic cephalopod

fauna of the Fort Douglas area, Utah: Walker Mus.

Mem., vol. 1, No. 1, p. 7. 

1929. Gurleyites. Mathews, idem, p. 43. 

Not 1886. Sibirites. Mojsisovics, Arktische Triasfaunen:

Acad. imp. sci. St.-P6tersbourg M6m., 7th ser., vol.

33, No. 6, p. 58.

Type: "Sibirites" kingianus Waagen, 10 from the 

Lower Triassic upper Ceratite limestone (Anasibirites 

beds), of the Salt Range in India.

Shell moderately involute, somewhat compressed 

laterally; venter rounded or flat, in some specimens 

with a shallow depression bordered by shoulder angles. 

Cross section rounded or subangular, usually higher 

than wide. Sculpture consisting of numerous ribs, 

usually single, running nearly straight up the flanks, 

crossing the venter in a shallow, forward-pointing 

series. These ribs at maturity are mostly very fine, 

coarser in youth, and almost invariably bundled; they 

became nearly obsolete at maturity.

In the adolescent stages there are invariably rather 

coarse ribs, and every third or fourth one stands out 

above the others as a distinct collar rib. This is the 

most striking character of the genus, recapitulating 

the coarse-ribbed Permian Xenodiscus.

The septa are invariably serrated, with rounded and 

entire saddles. The external lobe is divided by a 

shallow saddle into two rather narrow branches that 

may be either goniatitic or serrated. The first and 

second lateral lobes are invariably serrated, and the 

auxiliary may be either goniatitic or serrated. The 

internal septa show a very long tongue-shaped anti10 Waagen, W., Fossils from the Ceratite formation: India Oeol. Survey Mem., 

Palaeontologia Indica, 13th ser., Salt Range fossils, vol. 2, p. 108, pi. 8, figs. 1, 2, 1895.
70 LOWER TRIASSIC AMMONOLDS OF NORTH AMERICA

siphonal (bifid?), flanked by a shallow serrated internal 

lateral.

The length of the body chamber is about threefourths of a revolution. Waagen, who named the 

first species of this genus, states that the body chamber 

is very long, which has not been substantiated. 

Arthaber H also says that the body chamber of 

Pseudosibirites is very long, basing his statement 

upon Waagen's supposed observation. Welter, 12 after 

an examination of a large number of specimens, states 

that the length of the body chamber is not greater 

than three-fourths of a revolution. This statement 

agrees with the observations of the writer, made upon 

a very much larger number of individuals.

Anasibirites was originally included in Sibirites, and 

Mojsisovics's original description, although his type 

was the Lower Triassic Arctic Sibirites pretiosus, 

seems to have been based largely on the Upper Triassic 

group of "Sibirites," now referred to Metasibirites, of 

the family Haloritidae.

Krafft and Diener 13 regard Sibirites and Anasibirites 

as synonyms and members of the Meekoceratidae. 

This view may be correct, for the long body chamber, 

supposed to be characteristic of the Arctic Sibirites, 

and the alternate meeting of the ribs on the venter 

are probably no more true of them than for the forms 

from India referred to Anasibirites.

The true Sibirites are generally regarded as members 

of the Haloritidae, but Arthaber 14 places Sibirites in 

the Meekoceratidae, and Anasibirites ( = Pseudosibirites) in the Gastrioceratea. There can, however, 

now be no doubt that Anasibirites is a member of the 

Meekoceratidae, a ceratitoid, with no kinship with 

Metasibirites, and that it is a descendant of Xenodiscus 

and a probable ancestor of at least some of the groups 

of Ceratites. The immediate progenitor of Anasibirites 

may have been Kashmirites, which antedates Anasibirites in geologic occurrence and greatly resembles 

the adolescent stages of it.

Anasibirites was once believed to be very rare, as 

it was known only in a few fragments from the Upper 

Ceratite limestone of the Salt Range. Now it is known 

to be very abundant at the same horizon the Anasibirites zone in India, Timor, Svalbard, and Utah.

Anasibirites angulosus (Waagen)

Plate 79, Figures 13-15

1895. Sibirites angulosus. Waagen, Fossils from the Ceratite 

formation: India Geol. Survey Mem., Palaeontologia 

Indica, 13th ser., Salt Range fossils, vol. 2, p. 117, 

pi. 8, figs. 12a-c, 13a, b.

11 Arthaber, O. von, Die Trias von Albanien: Beitr. Palaontolo'gie Oesterr.- 

Ungarns u. des Orients, Band 24, p. 254, 1911.

12 Welter, O. A., Die Ammoniten der Unteren Trias von Timor: Palaeontologie 

von Timor, Lief. 11, Abh. 19, p. 139, 1922.

13 KrafTt, A. von, and Diener, Carl, Lower Triassic Cephalopoda from Spiti, 

Malla Johar, and Byans: India Geol. Survey Mem., Palaeontologia Indica, 15th 

ser., vol. 6, p.-179, 1909.

14Arthaber, O. von, Die Trias von Albanien: Beitr. Palaontologie Oesterr.-Ungarns u. des Orients, Band 24, p. 254, 1911.

1905. Sibirites angulosus. Noetling, Die asiatische Trias: 

Lethaea geognostica, Teil 2, Das Mesozoicum, Band 1, 

Trias, pi. 28, fig. 4.

1929. Anasibirites pseudoibex. Mathews, The Lower Triassic 

cephalopod fauna of the Fort Douglas area, Utah: 

Walker Mus. Mem., vol. 1, No. 1, p. 21, pi. 3, figs. 

28-31; pi. 7, fig. 46.

This species was first described from the Anasibirites 

beds of India. It is rather common at the same 

horizon in Timor and has been described by Mathews 

from the Anasibirites beds of Utah under the name 

A. pseudoibex. The description below is taken from 

Mathews's description of that species.

The shell is involute, discoidal, rugose, embracing; high 

angular whorl moderately indented by the penultimate volution. 

The sides are flat and slope from the umbilical shoulder to the 

ventral shoulder. The umbilical shoulder is'sharply rounded, 

and the inner wall is vertical. The ventral shoulder is sharply 

angular. The living chamber is more than one-half of the last 

volution. The umbilicus is moderately wide, showing one-half 

of the preceding volution. It is one-fourth the diameter of the 

shell, and its shoulder diameter is over twice its depth. The 

height of the last whorl is one and one-fourth times its thickness 

and less than one-half its diameter. It is indented to less than 

one-third its height by the penultimate volution and conceals 

one-half of this volution. The width of the shell is one-third 

its diameter. The distance across the penultimate volution 

from suture to suture is nearly twice the involution. The 

venter is one-half the width of the shell and is uniformly flat and 

uniformly sculptured.

The surface is ornamented with prominent, heavy, coarse, 

flexuous, progressive radial ribs, which are uniform and evenly 

spaced across the venter. They cross the venter in a wide 

progressive arc with the steepest, slope toward the aperture. 

The primary ribs originate in the umbilical suture, cross the 

inner wall in a retrogressive manner, become somewhat enlarged 

where they cross the umbilical shoulder, and are somewhat less 

distinct on the flanks. Some primaries bifurcate at the umbilical shoulder and cross the side wall with equal intensity. 

The auxiliary ribs originate either at the umbilical suture, on 

the inner wall, or on the lateral wall and cross the surface in 

line, with the primaries. There is no regularity as to the origin 

or distribution of the auxiliaries.

The sutures are ceratitic. The saddles are all evenly rounded 

and the lobes serrated. There are four serrations on the first 

lateral and two on the second, while the ventral lobe has two. 

The sutures are distinctly separated one from the other, the 

base of the saddle being even with the crest of the lobe of the 

next preceding suture.

This species may be confused with Sibirites ibex Waagen but 

is distinct from that species in possessing distinct auxiliary ribs, 

its trapezoidal form, its large umbilicus, and its sloping lateral 

walls. It is somewhat similar to Sibirites eichwaldi Keyserling, 

but the ribs cross the venter in a straight continuous line and 

there is no ventral furrow.

Horizon and locality: Pinecrest formation, Cephalopod 

Gulch, Fort Douglas Military Reservation, Utah.

Anasibirites bastini Mathews

Plate 80, Figures 3-5

1929. Gurleyites bastini. Mathews, The Lower Triassic cephalopod fauna of the Fort Douglas area, Utah: Walker 

Mus. Mem., vol. 1, No. 1, p. 49, pi. 10, figs. 7-11.

This species was described as belonging to a supposedly new genus but is clearly a typical member of
MEEKOCERATTDAE 71

Anasibirites. The diagnosis given below is quoted 

from that of Mathews.

This shell is involute, obovate, thin, laterally compressed; 

whorls high, moderately embracing, and indented by the inner 

volution. The sides are slightly convex and slope gently from 

the umbilical shoulders to the outer margins. The venter is 

slightly arched and smooth. The ventral shoulder is nearly 

square; the umbilical sharply rounded. The inner wall is 

nearly vertical. The umbilicus is broad, very shallow, and 

ellipsoidal. Its long diameter is nearly, one-fourth the greatest 

diameter of the shell and twice its own depth. The height of 

the last whorl is one and one-half times its greatest width and 

two-fifths its diameter. It is indented to one-third its height by 

the preceding volution and conceals nearly one-half this volution. 

The distance across the penultimate whorl from suture to suture 

is four-sevenths the greatest breadth of the shell and equal to 

the involution. The living chamber straightens and comprises 

nearly one-half of the last whorl.

The surface is ornamented with prominent, flexuous radial 

ribs, which, on the last whorl, develop high, very prominent 

elongated nodes'on the umbilical shoulder. In the earlier 

whorls the ribs are less distinct, more evenly developed, and 

more regular. The entire surface is covered with very fine, 

flexuous costae. The larger ribs form indistinct nodes at the 

ventral shoulder and cross the venter in an almost straight line. 

The inner whorls show ornamentation.

The sutures are ceratitic. The ventral lobe is divided by a 

V-shaped siphonal saddle. The lateral prongs are serrated. 

The lateral lobes are moderately broad, long, and deeply 

denticulated. The lateral saddles are wide and smooth.

Horizon and locality: Upper Anasibirites bed, Pinecrest formation, Pinecrest Ridge, Fort Douglas Military Reservation, 

Utah.

Anasibirites desertorum Smith, n. sp.

Plate 52, Figures 7-11; Plate 56, Figures 19, 20

Shell robust, laterally compressed, involute, deeply 

embracing, with steep umbilical walls, gently arching 

flanks, angular ventral shoulders, and rather narrow 

flattened venter. Ornamented with fine ribs that 

curve gently forward on the flanks and cross the venter 

without interruption. These ribs are somewhat bundled on the flanks but irregularly. Septa ceratitic.

The height of the last whorl is half the diameter of 

the shell; the width is two-thirds of the height; the 

width of the umbilicus is somewhat less than onefourth of the diameter of the shell. The outer whorl 

embraces two-thirds of the inner and is indented to 

nearly one-third of the height.

Anasibirites desertorum is very similar to A. tenuistriatus Waagen, 15 from the Lower Triassic Anasibirites beds of the Salt Range in India. Waagen's illustrations are confessedly restorations from fragments, 

but the resemblance to A. desertorum is very striking.

Horizon and locality: Rare in the Owenites subzone 

of the Meekoceras zone of Union Wash, Inyo Mountains, about 15 miles southeast of Independence, Inyo

ls Waagen, W., Fossils from the Ceratite formation: India Oeol. Survey Mem., 

Palaooutologia Indica, 13th ser., Salt Range fossils, vol. 2, p. 124, pi. 9, figs. 1, 2,1895.

County, Calif.; also at the same horizon at the mouth 

of Cottonwood Canyon, Phelan ranch, east side of the 

Ruby Range, Elko County, Nev.; also at the same 

horizon at Rohner's ranch, mouth of Paris Canyon, 

1 mile west of Paris, Idaho; associated with Owenites 

koeneni, Inyoites oweni, Lanceolites bicarinatus, Pseudosageceras multilobatum, and other forms.

Anasibirites emmonsi Mathews

' Plate 79, Figures 22, 24

1929. Anasibirites emmonsi. Mathews, The Lower Triassic 

cephalopod fauna of the Fort Douglas area, Utah: 

Walker Mus. Mem., vol. 1, No. 1, p. 14, pi. 2, figs. 

20-26.

1929. Anasibirites welleri. Mathews, op. cit., p. 14, pi. 2, figs. 

17-19.

1929. Anasibirites crickmayi. Mathews, op. cit., p. 16, pi. 3, 

figs. 24-27.

1929. Anasibirites vanbuskirki. Mathews, op. cit., p. 26, pi. 4, 

figs. 36-38.

This species is closely related to Anasibirites 'tenuistriatus Waagen and to A. multiformis Welter but seems 

to be sufficiently differentiated from both. However, 

A. welleri, A. crickmayi, and A. vanbuskirki must be 

put in the synonymy of A. emmonsi.

The description given below is quoted from that of 

A. emmonsi by Mathews in the paper cited above.

This form is reasonably compressed, involute, discoidal, 

with whorls deeply embracing, covering nearly five-eighths of 

the preceding volution, and being indented to one-third its 

height. The umbilicus is moderately wide and shallow; the 

shoulders are abruptly rounded. The sides are nearly flat, 

being curved near the margins, with the highest point near the 

umbilical shoulder. The inner wall is highly inclined. The 

height of the last whorl is a little less than one and two-thirds 

times its greatest width and nearly one-half its diameter. The 

distance across the penultimate volution from suture to suture 

is equal to its involution. The cross section of the last whorl 

is broadly trapezoidal. ,

The surface is ornamented with very fine, closely set, indistinct, flexuous radial ribs, that originate in the umbilical suture, 

separate as they cross the lateral wall, and become most distinct 

on the venter. There is a well-developed grouping of the sculpture consisting of from seven to nine ribs, which is distinct on 

the side walls and venter.

The cross section of the first whorl is rounded, and broader 

than deep; the second whorl is elliptical, the plane of the ellipse 

is the same as that of the shell; and the third volution has the 

same characters as the adult.

The sutures are ceratitic, consisting of two smooth lateral 

saddles and two lobes. The lobes are notched by five and 

four serrations, on the first and second laterals, respectively. 

The siphonal saddle is well developed between the simple serrated ventral-lobe prongs.

This species is chaaracterized by its width, its very fine ribs, 

its uniformity in the gradual development of its coils, and its 

comparatively wide venter.

Horizon and locality: Pinecrest formation, Pinecrest Ridge, 

Fort Douglas Military Reservation, Utah.
72 LOWER TRIASSIC AMMONOIDS OF NORTH AMERICA

Anasibirites hircinus (Waagen)

Plate 79, Figures 11, 12

1895. Sibirites hircinus. Waagen, Fossils from the Ceratite 

formation: Palaeontologia Indica, 13th ser., Salt 

Range fossils, vol. 2, p. 123, pi. 9, fig. 4.

1929. Anasibirites blackwelderi. 'Mathews, The Lower Triassic 

cephalopod fauna of the Fort Douglas area, Utah: 

Walker Mus. Mem., vol. 1, No. 1, p. 13, pi. 2, figs. 10- 

14.

This species was first described from-the Anasibirites 

beds of India; it occurs at the same horizon on Timor 

and has been described, under the name Anasibirites 

blackwelderi, from Utah. The diagnosis given below 

is taken from Mathews's description of that supposed 

species.

This form is involute, nearly discoidal, very thin, laterally 

compressed, with whorls high, deeply embracing, and well 

indented by the penultimate volution. The sides are nearly 

flat and slope gently from the umbilical shoulder to the ventral 

shoulder. The venter is flat, and the ventral shoulder is 

square.' The umbilical shoulder is slightly rounded. The 

inner wall is sloping at an angle of about 60° to the surface of 

the preceding volution. The umbilicus is medium sized, shallow 

and approximately as wide as the greatest breadth of the shell. 

It is one-fifth the diameter. The height of the last whorl is 

nearly twice its thickness and one-half its diameter. It is 

indented to almost one-third its height by the penultimate 

volution and conceals three-fourths of this volution. The 

distance across the penultimate volution from umbilical suture 

to umbilical suture equals the involution.

The surface is ornamented with nearly uniform, distinct, 

flexuous radial ribs. Some of these ribs bifurcate on the side 

walls. The ribs cross the venter in a slightly progressive 

manner. The entire surface is covered with very fine costae.

The first whorl is wider than its height; the second whorl is 

about equal; the third whorl is elliptical with the long axis in 

the plane of the shell; and the fourth whorl has the character 

of the adult. The siphuncle is ventral throughout the entire 

series. . This species is characterized by its highly compressed condition. It is a common form in the Anasibirites beds.

Horizon and locality: Pinecrest formation, Fort Douglas 

Military Reservation, Utah.

Anasibirites kingianus (Waagen)

Plate 79, Figures 19-21

1895. Sibirites kingianus. Waagen, Fossils from the Ceratite 

formation: Palaeontologia Indica, 13th ser., Salt Range 

fossils, vol. 2, p. 108, pi. 8, figs. 1 a-c, 2 a-c.

1922. Anasibirites multiformis (part). Welter, Die Ammoniteu 

der Unteren Trias von Timor: Palaeontologie von 

Timor, Lief. 11, Abh. 19, p. 138, pi. 169, figs. 9-16, 

Forma 1; pi. 170, figs. 6-10, Forma 5.

1929. Anasibirites edsoni. Mathews, The Lower Triassic 

cephalopod fauna of the Fort Douglas area, Utah: 

Walker Mus. Mem., vol. 1, No. 1, p. 27, pi. 4, figs. 

29-32.

1929. Anasibirites bassleri. Mathews, op. cit., p. 28, pi. 4, 

figs. 33-35.

1929. Anasibirites kingianus. Mathews, op. cit., p. 8, pi. 7, 

figs. 14-22.

This form is involute, discoidal, thick, with whorl high, 

embracing, and moderately indented by the penultimate

volution. The sides are broadly curved. The arc formed by a. 

cord drawn from shoulder to shoulder is moderately high with 

the greatest curve toward the umbilical shoulder. The shoulders 

are broadly rounded, and the inner wall is nearly vertical. 

The venter is. wide and broadly arched. It is three-fourths the 

greatest width of the shell. The living chamber comprises 

three-fourths of the last volution. The cross section of the 

living chamber is quadrangular with sides nearly equal. The 

height of the last whorl is a little greater than its greatest 

thickness and one-half its diameter. The diameter of the 

umbilicus is nearly one-fourth the diameter of the shell. It is 

one-third as deep as it is broad. The distance across the 

penultimate volution from suture to suture is one-half the 

greatest breadth of the shell and greater than the involution. 

' The surface is ornamented with regular, fine, flexuous, even, 

radial ribs, which are grouped across the umbilical shoulder in 

such a manner as to form elongated ridges. The ribs originate 

in the umbilical suture, crossing the shoulder and side wall in a 

progressive manner, becoming more pronounced and distinct as 

they cross the venter, where they are again grouped forming 

indistinct folds.

The sutures are ceratitic, forming three even, deep saddles and 

two lobes on the side wall. The siphonal saddle is distinct, deep, 

and smooth. The ventral lobe has two prongs which are 

serrated by two denticulations.

This species is characterized by its thickness, its wide venter, 

and its rather loose coil.

Horizon and locality: Pinecrest formation, Baffle Ridge, 

Fort Douglas Military Reservation, Utah.

This species was first described from the Anasibirites beds of India. It is abundant in the same horizon 

on Timor. The description given above is taken from 

Mathews's description of Anasibirites bassleri, a 

synonym of A. kingianus.

Anasibirites kingianus (Waagen) var. inaequicostatus Waagen

Plate 79, Figures 16, 17

1895. Anasibirites inaequicostatus. Waagen, Fossils from the 

Ceratite formation: Palaeontologia Indica, 13th ser., 

Salt Range fossils, vol. 2, p. 113, pi. 8, figs. 7 a, b; 8 b.

1922. Anasibirites multiformis (part). Welter, Die Ammoniten 

der Unteren Trias von Timor: Palaeontologie von 

Timor, Lief. 11, Abh. 19, p. 138, pi. 169, figs. 17, 18; 

pi. 170, figs. 6-10. (Not pi. 169, figs. 14-16.)

1929. Anasibirites perrini. Mathews, The Lower Triassic 

cephalopod fauna of the Fort Douglas area, Utah: 

Walker Mus. Mem., vol. 1, No. 1, p. 18, pi. 3, figs. 34-36.

The specific description is quoted from Mathews's 

paper, cited above.

This form is compressed, involute, discoidal; whorls high, 

moderately embracing, covering one-half of the inner volution. 

It is indented to one-fourth its height by this volution. The 

umbilicus is wide and shallow and reveals all of the inner whorls. 

The umbilical shoulder is sharply rounded. The ventral 

shoulder is broadly rounded; the inner wall is almost vertical. 

The sides are convex, with the greatest convexity near the 

umbilical shoulder. The greatest width of the shell is midway 

between the shoulders. The whorl is high, being less than onehalf the diameter. It is indented to one-fourth its height by the 

preceding volution. The thickness is three-fourths the height 

and less than one-third the diameter. On another specimen the 

distance across the penultimate volution from suture to suture 

is greater than its involution. The venter is well developed, is 

flat or depressed on the abandoned portion of the shell and
MEEKOCERATIDAE 73

rounded on the living chamber. The living chamber comprises 

more than one-half the last volution.

The surface is ornamented with well-developed, irregular, 

flexuous, progressive radial ribs, consisting of one primary to 

every five secondaries. The primary is followed by a distinct 

furrow, which extends from the umbilical shoulder across the 

venter. The ribs show the same arrangement on all preceding 

whorls. As the ribs cross the venter they become highly progressive and deeply arched. The ribs are much less distinct 

on the living chamber than on the abandoned part of the shell.

The sutures are ceratitic, consisting of three lateral saddles 

and two lobes. The sutures ride the ribs.

This variety was described as a species by Waagen 

from, the Anasibirites beds of India. It is common at 

the same horizon on Timor. It occurs sparingly in 

the Pinecrest formation, Baffle Ridge, Fort Douglas 

Military Reservation, Utah.

Anasibirites lindgreni Smith, n. sp.

 Plate 53, Figures 13-17

Shell of moderate size, robust, somewhat compressed 

laterally, openly umbilicate, with abruptly rounded 

umbilica shoulders, subangular ventral shoulders, and 

flattened, venter. Ornamented with numerous coarse 

lateral ribs that extend across the venter, and with 

short knobs or tubercles at the ventral angle. These 

knobs become obsolete in age. Septa unknown.

The outer whorl is greater than half the diameter of 

the shell; the width is abou t three-fourths of the height; 

the width of the umbilicus is one-fifth of the diameter 

of the shell.

Anasibirites lindgreni resemble A. noetlingi; differing 

in its fewer and coarser ribs. It has also a near kinship with. A. ibex Waagen 16 of the Anasibirites beds of 

India, from which it differs in its more numerous ribs 

and its more robust and less compressed whorl.

Named in honor of Dr. Waldemar Lindgren.

Horizon and. locality: Rare in the Lower Triassic 

Owenites subzone of the Meekoceras zone, at Union 

Wash, Inyo Mountains, about 15 miles southeast of 

Independence, Inyo County, Calif., associated with 

Meekoceras gracilitatis, Owenites koeneni, Inyoites 

oweni, Lanceolites bicarinatus, Anasibirites noetlingi, 

A. desertorum, Pseudosayeceras multilobatum, and other

forms.

Anasibirites mojsisovicsi Mathews

Plate SO, Figures 1,2

1929. Anasibirites mojsisovicsi. Mathews, The Lower Triassic 

cephalopocl fauna of the Fort Douglas area, Utah: 

Walker Mus. Mem., vol. 1, No. 1, p. 30, pi. 5, figs. 1-3.

1929. Anasibirites gibsoni. Mathews, op. cit., p. 29, pi. 5, figs. 

4,5.

The diagnosis of this species is taken from that given 

by Mathews. Anasibirites gibsoni can .hardly be 

any tiling but the young of A. mojsisovicsi and is 

therefore listed in synonymy.

111 Waagon, W., Fossils from the Ccratitc formation: India Oeol. Survey Mem., 

Piilaoontologm Indica, 13th ser., Salt Range fossils, vol. 2, p. 121, pi. 9, fig. 3,1895.

This species is compressed, moderately involute, discoidal; 

whorl high and deeply embracing. The umbilicus is broad and 

shallow, being one-fourth the diameter of the shell and three 

times its depth. The umbilical shoulder is sharply rounded; the 

ventral shoulder is angular. The sides are convex, with the 

highest point one-half the distance between the shoulders. 

The height of the last whorl is nearly twice its thickness and less 

than one-half its diameter. It is indented by the penultimate 

volution to nearly one-half its height and conceals a little more 

than one-half of this volution. The distance across the penultimate volution from suture to suture nearly equals its involution. 

The venter is narrow, being one-third the greatest width of the 

shell, and concave. The ribs and venter form an interrupted, 

irregular double keel. The living chamber comprises more than 

one-half the last whorl.

The surface is ornamented with very coarse, prominent, irregular, progressive, flexuous, radial ribs, which become nearly 

obsolete across the venter. The ribs originate in the umbilical 

suture, cross the inner wall in a retrogressive manner, make a 

broad curve as they cross the umbilical shoulder, and cross the 

lateral wall in a wavy manner, ending abruptly in distinct 

nodes at the ventral shoulder.

The sutures are ceratitic, being composed of three saddles and 

two lobes. The lobes are broad and serrated by four and three 

serrations on the first and second laterals, respectively. The 

saddles are broadly rounded and are not incised.

This species is entirely different from any other described.

Horizon and locality: Pinecrest formation, Pinecrest Ridge, 

Fort Douglas Military Reservation, Utah.

Anasibirites multiformis Welter

Plate 79, Figure 18

1922. Anasibirites multiformis. Welter, Die Ammoniten der 

Unteren Trias von Timor: Palaeontologie von Timor, 

Lief. 11, Abh. 19, p. 138, pi. 169, figs. 17, 18, 21, 22; 

pi. 170, figs. 1-5; pi. 171, figs. 1-3. (Not pi. 169, figs. 

16, 19-20, 23-27; nor pi. 170, figs. 6-19; nor pi. 171, 

figs. 4-17.)

1929. Anasibirites alternatus. Mathews, The Lower Triassic 

cephalopod fauna of the Fort Douglas area, Utah: 

Walker Mus. Mem., vol. 1, No. 1, p. 23, pi. 4, figs. 22, 23.

1929. Anasibirites romeri. Mathews, op. cit., p. 23, pi. 4, figs. 

24, 25.

1929. Anasibirites madisoni. Mathews, op. cit., p. 11, pi. 1, 

figs. 23-26.

This species is exceedingly common in the Anasibirites beds of Timor; it has been described by Mathews, 

under the three names given above, from the same 

horizon in Utah. Tne description given below is 

taken from that by Mathews of A. alternatus.

The form is discoidal, moderately involute, rugose, laterally 

compressed, with medium width, and with whorls moderately 

high and embracing. The umbilical shoulder is not prominent; 

the inner walls slope at an angle of about 45°, and the umbilicus 

is wide and shallow. The ventral shoulders are sharply curved; 

the sides are flattened, somewhat curved, and slope gently from 

the greatest width of the shell to the umbilical shoulder and more 

steeply to the ventral shoulder. The venter is wide, forming 

about two-thirds the greatest width of the shell and greatly 

curved. The height of the last whorl is one-fourth greater 

than its greatest thickness and one-half the diameter of the shell. 

The last volution conceals about one-half the penultimate 

volution.

The surface is ornamented with very strong, slightly progressive radial ribs. The prominent primary ribs are very well
74 LOWER TRIASSIC AMMONOIDS OF NORTH AMERICA

developed, and the secondary ribs, which alternate with the 

primaries, are well developed but less prominent. The intensity 

of the ribs increases from the umbilical shoulder toward the 

venter, where they reach their maximum development. The 

ribs are sharp and alternate as they cross the venter. Very fine 

costae cover the entire surface. Every second primary rib of the 

last volution corresponds with the primary rib of the next preceding volution in such a manner that the penultimate volution 

is marked on the umbilical shoulder and inner wall with two 

secondary ribs between two primaries. This unusual character 

gives a beautiful sculpture to the species.

Horizon and locality: Pinecrest formation, Baffle Ridge, Fort 

Douglas Military Reservation, Utah.

Anasibirites multiformis Welter var. hyatti Mathews

1929. Anasibirites hyatti. Mathews, The Lower Triassic cephalopod fauna of the Fort Douglas area, Utah: Walker 

Mus. Mem., vol. 1, No. 1, p. 30.

The description given below is taken from that by 

Mathews of the supposed species Anasibirites hyatti, 

which can not be more than a variety of the oriental 

A. multiformis.

The shell is involute, obovate, laterally compressed, with 

whorls high, deeply embracing, and well indented by the penultimate volution. The sides are a flattened curve with the highest 

peak of the curve about midway between the two shoulders. 

The inner wall is nearly vertical; the ventral shoulder is roughly 

angular, and the umbilical shoulder forms a wide curve. The 

umbilicus is broadly elliptical, narrow, and shows only about 

one-sixth of the preceding volution. The height of the last 

whorl is nearly twice its thickness and one-half its diameter. 

It is indented to one-half its height by the penultimate volution 

and conceals five-sixths of that volution. The width of the 

shell is one-third its diameter. The distance across the penultimate volution from suture'to suture is five-eighths its breadth 

and equal to the involution. The 'venter is five-eighths the 

greatest width of the shell and is flat.

The surface is ornamented with prominent, well-defined, 

flexuous, progressive radial ribs, which cross the venter in a 

straight line. The arrangement of the ribs shows a grouping of 

two or three primaries with two to four secondaries between. 

The primary ribs start on the umbilical shoulder and continue 

prominently across the lateral wall to the ventral shoulder. 

The secondary ribs rise in the umbilical suture, follow the general 

outline of the primaries, but do not become decidedly enlarged 

until they reach the venter, where they are evenly spaced and 

equally developed with the primaries. The whole surface is 

covered with very fine costae.

Horizon and locality: Pinecrest formation, Pinecrest Ridge, 

Fort Douglas Military Reservation, Utah.

Anasibirites noetlingi (Hyatt and Smith)

Plate 9, Figures 1-3

1905. Sibirites noetlingi. Hyatt and Smith, The Triassic cephalopod genera of America: U. S. Geol. Survey Prof. 

Paper 40, p. 49, pi. 9, figs. 1-3.

Shell moderately involute, laterally compressed. 

Whorl deeply embracing, increasing slowly in height, 

not deeply indented by the inner volutions. Sides flattened, umbilical shoulder subangular, venter broad and 

flattened. Umbilicus moderately wide and deep, showing all the interior volutions. The height of the last 

whorl is about three-sevenths of the total diameter,

and it is indented to slightly more than one-fourth of 

its height by the inner volution. The width of the whorl 

is more than three-fourths of the height. The width 

of the umbilicus is one-fourth of the total diameter.

Surface ornamented with radial flexuous ribs, fine 

and coarse ribs alternating. These begin, without 

knots, on the umbilicus/ curve gently forward high up 

on the flanks, and then run straight across the venter. 

There is a faint suggestion of nodes where the ribs cross 

the abdominal shoulders.

The septa are unknown.

Anasibirites noetlingi is nearly allied to A. hircinus 

Waagen, 17 from the Upper Ceratite limestone of India, 

but differs from that species in its fine sculpture and 

more numerous ribs. They both, however, belong 

to the same group.

Horizon and locality: Anasibirites noetlingi was 

found by J. P. Smith in the Lower Triassic Meekoceras 

zone of the Inyo Range, 1 % miles east of Union Spring, 

on the old McAvoy trail across to Saline Valley, on the 

east side of Owens Valley, about 15 miles southeast of 

Independence, Inyo County, Calif., associated with 

Meekoceras gracilitatis, M. mushbachanum, M. newberryi, ' Owenites koeneni, Inyoites oweni, Pseudosageceras multilobatum, and many other species.

Anasibirites tenuistriatus (Waagen)

Plate 79, Figures 9, 10

1895. Sibirites tenuistriatus. Waagen, Fossils from the Ceratite formation: Palaeontologia Indica, 13th ser., Salt

Range fossils, vol. 2, p. 124, pi. 9, figs. 1 a-d, 2 a-e. 

1929. Anasibirites salisburyi. Mathews, The Lower Triassic

cephalopod fauna of the Fort Douglas area, Utah:

Walker Mus. Mem., vol. 1, No. 1, p. 9, pi. 1, figs. 27,

29; pi. 2, figs. 1, 2. 

1929. Anasibirites johannseni. Mathews, op. cit., p. 12, pi. 1,

figs. 34, 36, 37. 

1929. Anasibirites whilei. Mathews, op. cit., p. 12, pi. 1, fig. 35;

pi. 2, figs. 15, 16. 

1929. Anasibirites fisheri. Mathews, op. cit., p. 13, pi. 2, figs.

3-9. 

1929. Anasibirites powelli. Mathews, op. cit., p. 15, pi. 3, figs.

1-5. 

1929. Anasibirites whitfieldi. Mathews, op. cit., p. 16, pi. 3,

figs. 6-8. 

1929. Anasibirites veranus. Mathews, op. cit., p. 17, pi. 3, figs.

18-23. 

1929. Anasibirites ketchami. Mathews, op. cit., p. 18, pi. 3, figs.

12-17. 

1929. Anasibirites weaveri. Mathews, op. cit., p. 19, pi. 3, figs.

10, 11, 32, 33. 

1929. Anasibirites wardi. Mathews, op. cit., p. 19, pi. 2, figs.

27-29. 

1929. Anasibirites mcclintocki. Mathews, op. cit., p. 22, pi. 4,

figs. 1-6. 

1929. Anasibirites dieneri. Mathews, op. cit., p. 24, pi. 4, figs.

19, 20. 

1929. Anasibirites clarki. Mathews, op. cit., p. 25, pi. 4, figs.

26-28.

» Waagen, W., op. cit., p. 123, pi. 9, fig. 4.
MEEKOCERATIDAE 75

1929. Anasibirites bretzi. Mathews, op. cit., p. 25, pi. 4, figs.

14-18; pi. 7,.fig. 13. 

1929. Anasibirites rollini. Mathews, op. cit., p. 27, pi. 1, figs.

30-33; pi. 4, figs. 10-13. 

1929. Anasibiriles gayi. Mathews, op. cit., p. 28, pi. 4, figs.

7-9.

This exceedingly variable species was first described 

by Waagen from the Anasibirites beds of India. It is 

common at the same horizon in Timor. Mathews has 

described it under a variety of names from the Anasibirites beds of Utah, and the description given below is 

taken from his description of "Anasibirites mcclintocki."

The shell is involute, discoidal, laterally compressed, thin, 

with whorl high, moderately embracing, and well indented by 

the penultimate volution. The sides are flatly curved, with the 

more gentle slope toward the ventral margin. The greatest 

breadth of the shell is at the umbilical shoulder. The inner wall 

is steep, forming an angle of about 50° with the side of the 

penultimate volution. The ventral shoulders are square. The 

umbilicus is reasonably wide and shows about one-third of the 

preceding volution, and is about one-fifth the diameter of the 

shell. The height of the last whorl is about one and one-half 

times the greatest width of the shell and is a little less than onehalf the greatest diameter. It is indented to about one-third of 

its height by the penultimate volution and conceals about twothirds of this volution. The width of the shell is one-third of 

its diameter. The living chamber comprises one-half of the last 

volution. The distance across the penultimate volution from 

suture to suture is a little greater than one-half of the greatest 

breadth of the shell and a little more than the involution. The 

diameter of the umbilicus is one-fourth the diameter of the shell 

and is twice as great as its depth. The venter is uniformly flat 

and is one-half the greatest width of the shell.

The surface is ornamented with well-defined, variable, flexuous, progressive radial ribs, which cross the venter in a slightly 

progressive arc. The ribs become crowded at the umbilical 

shoulder and unite, forming a somewhat indistinct elongated 

tubercle. These are connected with the umbilical suture by a 

slight elevation. The ribs are grouped in pairs set off by a distinct furrow which crosses the venter in line with the primaries.

This species is a progressive form and is not similar to any 

other.

Horizon and locality: Pinecrest formation, Cephalopod Gulch, 

Fort. Douglas Military Reservation, Utah.

Subgenus GONIODISCUS Waagen 17 "

1895. Goniodiscus. Waagen, Fossils from the Ceratite formation: India Geol. Survey Mem., Palaeontologia Indica, 

13th ser., Salt Range fossils, vol. 2, p. 126.

1929. Goniodiscus. Mathews, The Lower Triassic cephalopod 

fauna of the Fort Douglas area, Utah: Walker Mus. 

Mem., vol. ], No. 1, p. 31.

Type: Goniodiscus typus Waagen. 18

Shell laterally compressed, involute, with narrow 

venter, very slightly convex sides, and flattened 

biangular venter. The whorl is considerably higher

""This mime is preoccupied by Goniodiscus Mueller and Troschel, 1842, and has 

been replaced by ffemiprionites (Spath, L. F., Corrections of cephalopod nomenclature: The Naturalist, No. 871, p. 270, August, 1929). The correction was not 

noted by Professor Smith, and it has seemed best to leave his text as originally 

written. Editor.

'9 Waagen, W., op. cit., p. 128, pi. 9, figs. 7, 8.

67664 32 6

than wide. The surface has fine threadlike ribs 

and weak folds that cross the venter. Septa ceratitic, 

with rounded saddles and four external serrated lobes.

Waagen 19 refers this so-called genus to the 

Noritidae, on account of the siphonal notch in the 

median saddle, which was supposed to make the 

ventral lobe tripartite. The subgenus has, however, 

not the faintest resemblance to the Noritidae and 

clearly belongs to the greater group of Anasibirites, 

from which it may be distinguished only by obsolescence of the sculpture. It is merely a group of species 

under that genus, separated only for convenience 

and because of its abundance in the Lower Triassic 

of Timor.

The group is confined to the Anasibirites zone, near 

the top of the Lower Triassic in India, Timor, and 

western America. In the last-named region it is 

represented by four species, Anasibirites (Goniodiscus) 

typus Waagen, A. ornatus, A. smithi, and A. utahensis.

Anasibirites (Goniodiscus) ornatus Mathews

Plate 80, Figures 11, 12

1929. Goniodiscus ornatus. Mathews, The Lower Triassic 

cephalopod fauna of the Fort Douglas area, Utah: 

Walker Mus. Mem., .vol. 1, No. 1, p. 34, pi. 6, figs. 6-9.

The description given below is quoted from that of 

Mathews.

The form is obovate, thin, laterally compressed; whorl high, 

deeply embracing, and well indented by the preceding volution. 

The sides are broadly convex, with the greatest convexity 

near the umbilical shoulder. The ventral shoulder is angular, 

the umbilical shoulder broadly rounded. The inner wall is 

nearly vertical. The venter is flat and narrow. The umbilicus 

is roughly elliptical, narrow, and moderately deep, being onefourth the diameter of the shell and nearly one-half as deep as 

broad. The height of the last whorl is one-half the diameter 

and one and one-half times its greatest thickness. It is indented to one-third its height by the penultimate volution and 

conceals about two-thirds of this volution. The distance across 

the preceding volution from suture to suture is more than onehalf its greatest thickness and equal to the involution. The 

living chamber comprises more than one-half the last whorl. 

The shell is thin and smooth.

The surface is ornamented with a few rather distinct, flexuous 

radial folds or ribs, which originate in the umbilical suture, 

cross the inner wall in a retrogressive manner, forming a wide 

arc across the umbilical shoulder, where they become most 

prominent, then cross the side wall in an almost straight line, 

ending at the ventral shoulder. On the venter an indistinct 

siphonal ridge is noticeable.

The sutures on another specimen are ceratitic and almost 

identical with the sutures of Goniodiscus typus Waagen. However, they are more deeply incised.

The second whorl is smooth and nearly the same shape as 

the adult, but the venter is rounded. The third whorl has 

the same characteristics as the adult, except that the lateral 

folds are much more highly developed. The fourth whorl 

possesses all of the adult characteristics.

"Idem, p. 150.
76 LOWER TRIASSIC AMMONOIDS OF NORTH AMERICA

This species is characterized by its obovate shape, its ornamentation on the side walls, its flat narrow venter, and lacks 

the characteristic ventral keels.

Horizon and locality: Pinecrest formation, Cephalopod 

Gulch, Fort Douglas Military Reservation, Utah.

Anasibirites (Goniodiscus) smithi (Mathews)

Plate 80, Figures 13-15

1929. Gurleyites smithi. Mathews, The Lower Triassic cephalopod fauna of the Fort Douglas area, Utah: Walker 

Mus. Mem., vol. 1, No. 1, p. 43, pi. 10, figs. 1-6.

This species was chosen by Mathews as the type of a 

supposedly new genus, Gurleyites. It is a typical 

Goniodiscus, however, and the genus Gurleyites is 

dropped. The specific diagnosis given below is quoted 

from that of Mathews.

The form is involute, obovate, laterally compressed, some 

what robust, with high whorls. The early whorls are moder~ 

ately embracing; the last whorls slightly embracing and indented by the inner volution. The sides are moderately convex 

and slope gradually from near the umbilical shoulders to the 

outer margins. The venter is slightly arched and nearly smooth. 

The ventral shoulder is obtuse; the umbilical shoulder slightly 

rounded. Inner wall is vertical. Umbilicus is moderately 

broad, shallow, and ellipsoidal, its long diameter being nearly 

one-fourth the greatest diameter of the shell and three times 

its own depth. The height of the last whorl is one and threefifths times its greatest width and less than one-half of its 

diameter. It is indented to three-eighths its height by the 

inner volution and conceals over one-half this volution. The 

distance across the penultimate volution from umbilical suture 

to umbilical suture is one-half the greatest width of the shell 

and nearly equals the involution. The living chamber straightens and comprises one-half the last whorl.

The surface is ornamented with a few large, irregular, sigmoidal radial ribs, which are most prominent on the ventral 

s houlder. Some bifurcate on the side wall. The entire surface 

is covered by large, flexuous, radial auxiliary ribs or costae, 

which terminate in the ventral shoulder. The venter is crossed 

by indistinct, straight, broad, wavy undulations of the shell. 

The costae cross the inner wall in a retrogressive manner from 

the umbilical suture. The sculpture shows on the preceding 

volution.

The sutures are ceratitic, consisting of three lateral saddles 

and three lobes. The saddles are deep, broad, and smooth. 

The first lateral lobe is long and well developed, the second is 

one-half the size of the first, and the third may be considered 

the auxiliary. All the lobes are deeply denticulated. The 

ventral lobe is broad, moderately long, and divided by a wide, 

smooth siphonal saddle. The lateral prongs are sharply incised by four graduated serrations. The protoconch is large 

and nearly spherical; the first whorl is ellipsoidal with the long 

axis transverse to the plane of the shell. The second whorl as 

well as the remaining whorls have the characters of the adult.

This species has some characteristics of Meekoceras malayicum 

Welter; but it is more evolute, the umbilicus is ellipsoidal, the 

living chamber straightens, the venter is more nearly flat, 

the ornamentation is less highly developed, and the siphonal 

saddle is broad, shallow, and smooth.

Horizon and locality: Found only in the uppermost Anasibirites bed, Pinecrest formation, Cephalopod Gulch, Fort 

Douglas Military Reservation, Utah.

Anasibirites (Goniodiscus) typus Waagen

Plate 31, Figures 11, 12

1895. Goniodiscus typus. Waagen, Fossils from the Ceratite

formation: India Geol. Survey Mem., Palaeontologia

Indica, 13th ser., Salt Range fossils, vol. 2, p. 128, pi.

9, figs. 7-10. 

1922. Anasibirites mulliformis (part). Welter, Die Ammoniten

der Unteren Trias von Timor: Palaeontologie von

Timor, Lief. 11, Abh. 19, pi. 171, figs. 4-7. (Exclusive

of text and other figures.) 

1929. Goniodiscus typus. Mathews, The Lower Triassic cephalopod fauna of the Fort Douglas area, Utah:

Walker Mus. Mem., vol. 1, No. 1, p. 31, pi. 5, figs.

12-21. 

1929. Goniodiscus americanus. Mathews, op. cit., p. 32, pi. 5,

figs. 22-27. 

1929. Goniodiscus walcotti. Mathews, op. cit., p. 32, pi. 6, figs.

1-5. 

1929. Goniodiscus shumardi. Mathews, op. cit., p. 33, pi. 6,

figs. 11-14. 

1929. Goniodiscus slocumi. Mathews, op. cit., p. 34, pi. 6, figs.

15-17.

Form robust, involute, laterally compressed, with 

narrow umbilicus, flanks sloping gently upward from 

the abruptly rounded umbilical shoulders to the flat 

biangular venter. Surface with fine radial folds and 

nearly obsolete striae of growth.

The height of the whorl is slightly less than half the 

diameter of the shell, and the width is less than threefourths of the height. The width of the umbilicus is 

about one-fifth of the diameter of the shell. The outer 

whorl embraces nearly all of the inner and is indented 

by it to one-third of the height.

Horizon and locality: Very rare in the Anasibirites 

subzone of the Lower Triassic Meekoceras zone, at 

Rohner's ranch, south side of Paris Canyon, 1 mile west 

of Paris, Idaho; associated with Owenites cf. 0. koeneni, 

Inyoit'es sp.; also somewhat doubtfully identified from 

the same horizon in Union Wash, Inyo County, Calif., 

associated with Owenites koeneni, Inyoites oweni, 

Anasibirites desertorum, and other forms. It was first 

described from the Upper Ceratite limestone, Anasibirites zone, of the Salt Range, India. It is very common in the Anasibirites beds of Timor, associated with 

many species of Anasibirites, closely related to the 

American species.

This species has later been found by A. A. L. 

Mathews to be very common in the Anasibirites beds 

of Utah, where he has described it under a variety of 

names. The additional diagnosis given below is 

quoted from his description of Goniodiscus typus, for 

he has had much better material than the writer has 

had.

Disciform, involute, laterally compressed; whorls high, deeply 

embracing, and very well indented by the preceding volution. 

The sides are nearly flat, sloping from the greatest width of the 

shell to both shoulders. The cross section shows a nearly
MEEKOCERATIDAE 77

uniform low arc, with the highest point of the arc nearer the 

umbilical than the ventral shoulder. The ventral shoulder is 

angular, caused by a slight depression of the side wall just before 

it joins the venter. The umbilical shoulder is sharply rounded. 

The inner wall is nearly vertical. The umbilicus is narrow and 

deep. Its diameter is two and one-half times its depth and 

more than one-fourth the diameter of the shell. The height of 

the last whorl is one and one-half times its greatest thickness 

and one-half of the diameter. It is indented by the penultimate 

volution to one-third its height and conceals five-sixths of this 

volution. The distance across the penultimate volution from 

suture to suture is one-half the greatest width of the shell, equal 

to the width of the venter, and equal to the involution. The 

venter is smooth, nearly flat, and slightly arched. It shows 

indistinct parallel flutings. The living chamber comprises 

three-fourths of the last whorl. The shell is smooth and thin. 

It shows very little ornamentation and that only near the 

umbilical shoulder on the side wall. These are very faint, 

broad folds, which become obscure before they reach the ventral 

shoulder.

The sutures are ceratitic, consisting of three saddles and two 

distinct lobes. Two saddles are deep and smooth, the last 

lateral being shallow, poorly defined, and broad. The first 

lateral lobe is somewhat elongated, wide, and notched by six 

serrations; the second lateral is broad, short, and notched by 

four serrations. The auxiliary series consists of a short curved 

row of serrations following the third saddle. The ventral lobe 

is divided into three parts, with a low siphonal notch and two 

serrations on each side prong. The first lateral rides the keel.

This form is identical with Goniodiscus typus Waagen. 

Waagen made no mention of the flutings on the venter, but 

indistinct lines are indicated in his drawings. The redescription 

is taken from a specimen which is the same size as the original 

type. Many specimens are fully twice that size. Waagen 

described his species from fragments and small specimens, 

whereas the writer has many specimens, some very large and 

with shells well preserved. As the shell attained larger dimensions, the sculpture remained weak.

Horizon and locality: Pinecrest formation, Pinecrest Ridge, 

Fort Douglas Military Reservation, Utah.

?Anasibirites (Goniodiscus) varians Mathews

1929. Goniodiscus? varians. Mathews, The Lower Triassic 

cephalopod fauna of the Fort Douglas area, Utah: 

Walker Mus. Mem., vol. 1, No. 1, p. 35, pi. 7, figs. 

26-39.

This doubtful species is the young of almost any 

species of Goniodiscus, or of several. It can hardly 

be recognized as independent but is listed here for the 

salce of completeness.

Horizon and locality: Pinecrest formation, Anasibirites subzone, Cephalopod Gulch, Fort Douglas 

Military Reservation, Utah.

Anasibirites (Goniodiscus) utahensis Mathews

Plate 80, Figures 9, 10

1929. Goniodiscus utahensis. Mathews, The Lower Triassic 

cephalopod fauna of the Fort Douglas area, Utah: 

Walker Mus. Mem., vol. 1, No. 1, p. 33, pi. 6, figs. 

29-31.

The description given below is quoted from that of 

Mathews.

Form involute, moderately thick, laterally compressed; 

whorl high, deeply embracing, and well indented by the inner

volution. The sides are broadly convex, sloping equally from 

the greatest width of the shell to the shoulders. Just before 

reaching the ventral shoulder they flatten slightly. The 

venter is broad and flat. It unites with the side walls in such 

a manner as to form two rudimentary keels. The umbilical 

shoulder is sharply rounded. The inner wall is nearly vertical. 

The umbilicus is very narrow and deep. The height of the 

last whorl is one-half the diameter, and its thickness is equal 

to three-fifths of its height. It is indented to four-fifths its 

greatest thickness and one-half its height by the preceding 

volution and conceals five-sixths of this volution. The distance 

across the inner volution from suture to suture is three-fourths 

the involution. The living chamber is greater than one-half 

the last volution: The shell is thin and smooth.

The surface is marked by indistinct, broad, flexuous, radial 

folds, which form broad undulations on the venter, producing 

a wavy appearance.

The sutures are ceratitic, consisting of the same number of 

lobes, saddles, and the same arrangement as in Goniodiscus 

typus Waagen.

This species is characterized by its remarkable breadth and 

its peculiar, indistinct sculpture or markings.

Horizon and locality: Pinecrest formation, Pinecrest Ridge, 

Fort Douglas Military Reservation, Utah.

Genus HEDENSTROEMIA Waagen

1895. Hedenstroemia. Waagen, Fossils from the Ceratite

formation: India Geol. Survey Mem., Palaeontologia

Indica, 13th ser., Salt Range fossils, vol. 2, p. 140. 

1897. Hedenstroemia. Diener, Cephalopoda of the Lower Trias:

India Geol. Survey Mem., Palaeontologia Indica,

15th ser., Himalayan fossils, vol. 2, pt. 1, p. 60. 

1900. Hedenstroemia. Hyatt, Cephalopoda, in Zittel, K. A.

von, Textbook of palaeontology, vol. 1 (translated by

C. R. Eastman), p. 555. 

1900. Anahedenstroemia. Hyatt, Cephalopoda, in Zittel, K. A.

von, Textbook of palaeontology, vol. 1 (translated by

C. R. Eastman), p. 555.

1905. Hedenstroemia. Hyatt and Smith, The Triassic cephalopod genera of America: U. S. Geol. Survey Prof.

Paper 40, p. 100. 

1909. Hedenstroemia. Krafft and Diener, Lower Triassic

Cephalopoda from Spiti, Malla Johar, and Byans: 

'India Geol. Survey Mem., Palaeontologia Indica,

15th ser., vol. 6, pt. 1, p. 147. 

1911. Hedenstroemia. Arthaber, Die Trias von Albanien:

Beitr. Palaontologie Oesterr.-Ungarns u. des Orients,

vol. 24, p. 207. 

1915. Hedenstroemia. Haniel, Die Cephalopoden der Dyas

von Timor: Palaeontologie von Timor, Lief. 3, Abh.

6, p. 148. 

1917. Hedenstroemia. Diener, Ueber Ammoniten mit Adventivloben: K. Akad. Wiss. Wien Denkschr., Band 93,

p. 169. 

1922. Hedenstroemia. Welter, Die Ammoniten der Untercn

Trias von Timor: Palaeontologie von Timor, Lief. 11,

Abh. 19, p. 96.

Septa complex", consisting of one or two adventitious 

lobes, three or more laterals, and a long auxiliary 

series. The lobes are all serrated and the saddles 

entire.

Hedenstroemia resembles Pseudosageceras, with which 

it is associated, in form but differs from that genus in 

lacking the lanceolate type of lobes. It also resembles 

Cordillerites Hyatt and Smith but does not have the
78 LOWER TRIASSIC AMMONOIDS OF NORTH AMERICA

complexity of the lateral lobes nor the tongue-shaped 

bifid lobes of the auxiliary series that are characteristic 

of Cordillerites.

The type species of Hedenstroemia was assigned by 

Mojsisovics to Meekoceras, but that genus never has 

adventitious lobes, nor a long series of auxiliaries, and 

therefore Waagen placed it in a new genus under the 

subfamily Hedenstroeminae in the Pinacoceratidae. 

This assignment was accepted by Diener,20 who added 

another species, H. mojsisovicsi Diener. Meekoceras 

furcatum Mojsisovics was also included by Waagen 

and Diener in Hedenstroemia, but Haug 21 assigned it to 

Norites, to which it has a certain resemblance in form. 

Mojsisovics 22 has chosen this species as the type of a 

new genus, Tellerites, under the family Noritidae.

Diener 23 has withdrawn Hedenstroemia from the 

Pinacoceratidae or the Beloceratea, and placed it 

again under the Meekoceratidae, as Mojsisovics did 

when he named the first species of the group. The 

writer agrees with him in this, for young specimens of 

Hedenstroemia kossmati are decidedly meekoceran in 

their septa and have no resemblance to the young of 

Pseudosageceras or Aspenites. The possession of 

adventitious lobes is not enough to place a form under 

Beloceratea.

Horizon and locality: Hedenstroemia was first found 

in the upper part of the Lower Triassic in northern 

Siberia and in the Himalaya Mountains in India. It 

has also been found by J. P. Smith in the Meekoceras 

zone of the Lower Triassic of southeastern Idaho and 

eastern California, in both places associated with 

Meekoceras gracilitatis and many other characteristic 

forms. It is also quite common in the Lower Triassic 

of Timor, and at the corresponding horizon in Albania.

Hedenstroemia hyatti Smith, n. sp.

Plate 27, Figures 13-18

Form involute, laterally compressed, deeply embracing, narrowly umbilicate; with biangular, narrow 

venter and shallow ventral furrow. Surface nearly 

smooth, with fine striae of growth.

Septa ceratitic, with rounded, entire saddles and 

serrated lobes, consisting of an adventitious lobe, short 

and weakly developed; a long, narrow external lobe; a 

large first lateral, longer and wider; a shorter, narrower 

second lateral; and a short series of auxiliaries, decreasing in size toward the umbilicus.

Hedenstroemia hyatti is very closely related to I~I. 

kossmati, from which it differs in its smaller size,

2° Diener, Carl, Cephalopoda of the Lower Trias: India Geol. Survey Mem., 

Palaeontologia Indica, 15th ser., Himalayan fossils, vol. 2, pt. 1, p. 60, 1897.

21 Haug, E., Les ammonites du Permien et du Trias: Soc. geol. France Bull., 

3d ser., vol. 22, p. 393, 1894.

22 Mojsisovics, E. von, Die Cephalopoden der Hallstattcr Kalke: K.-k. geol. 

Reichsanstalt Wien Abh., Band 6, Supplement-Heft, p. 311, 1902.

23 Diener, Carl, Ueber Ammoniton mit Adventivloben: K. Akad. Wiss. Wien 

Denkschr., Band 93, p. 169, 1917.

broader venter, and thicker whorl. It might be a 

variety of that species, but no intergradations have 

been observed.

Named in memory of Alpheus Hyatt.

Horizon and locality: Very rare in the Lower Triassic Meekoceras zone, at locality 1, 5 miles east of 

Grays Lake, southeastern Idaho; associated with 

Meekoceras gracilitatis, M. mushbachanum, Flemingites 

aplanatus, F. aspenensis, Clypeoceras muthianum, 

Hedenstroemia kossmati, Pseudosageceras multilobatum, 

Lanceolites compactus, Cordillerites angulatus, Aspenites 

acutus, and many other characteristic species.

Hedenstroemia kossmati Hyatt and Smith

Plate 28, Figures 11-16; Plate 41, Figures 1-10; Plate 67, 

Figures 3-7

1905. Hedenstroemia kossmati. Hyatt and Smith, The Triassic 

cephalopod genera of America: U. S. Geol. Survey 

Prof. Paper 40, p. 101, pi. 67, figs. 3-7; pi. 84, figs. 1-10.

Involute, discoidal; whorls laterally compressed, 

high and increasing rapidly in height. Venter narrow, 

triangular, and with slight ventral depression between 

the shoulder angles. Umbilicus narrow, almost closed. 

Surface smooth on both shell and cast.

The septa are complex, consisting of an adventitious 

series of lobes, laterals, and a long auxiliary series. The 

first adventitious lobe is short and narrow, less than 

half the size of the second lateral; the first lateral is 

slightly longer and about twice as broad as the adventitious lobe, and the second lateral is shorter and nearly 

as broad. The third lateral is shallow but shaped like 

the second. These are all distinctly serrated. Then 

follows a long series of short tongue-shaped auxiliaries, 

growing smaller toward the umbilicus.

In the later adolescent stage the ventral furrow is 

distinct but disappears before maturity. In the earlier 

adolescent stage the venter is rounded, the whorl proportionally more robust, and the surface is sculptured 

with lateral ribs. The young stages are somewhat like 

those of the Meekoceratidae, to which the genus is 

now assigned.

Hedenstroemia kossmati is evidently closely allied to 

PI. mojsisovicsi Diener 24 of the Lower Triassic of India, 

from which it differs chiefly in the narrowness of the 

umbilicus the shape of the whorl, the smooth surface, 

and the character of the septa being virtually identical 

in the two species. It is thought best, however, for the 

present to keep them separate, until sufficient material 

of the Indian and the American forms should be found 

to show whether they are perfectly similar at the same 

size.

Horizon and locality: Hedenstroemia kossmati was 

found by J. P. Smith in the Lower Triassic Meekoceras

24 Diener, Carl, Cephalopoda of the Lower Trias: India Oeol. Survey Mem., 

Palaeontologia Indica, 15th ser., Himalayan fossils, vol. 2, pt. 1, p. 63, pi. 20, fig. 1, 

1897.
HUNGARITIDAE 79

zone, at the head of Wood Canyon, 9 miles east of 

Soda Springs, in the Aspen Ridge, in southeastern 

Idaho, associated with Meekoceras gracilitatis White, 

M. mushbachanum White, Flemingites, Ussuria, Cordillerites, Nannites, Ophiceras, Aspenites, Pseudosageceras, 

and many other forms characteristic of the Lower 

Triassic. Probably the same species was found by 

J. P. Smith in the Meekoceras zone of Union Canyon, in 

the Inyo Range, about 15 miles southeast of Independence, Inyo County, Calif., associated with virtually the same fauna.

Hedenstroemia, in both Asia and America, is characteristic of an upper horizon of the Lower Triassic, the 

Flemingites beds, or what was formerly called by 

Diener the Subrobustus beds, later the Hedenstroemia 

beds, for the associated faunas are very similar in 

India, Siberia, Idaho, and California.

Subgenus CLYPITES Waagen

1895. Clypites. Waagen, Fossils from the Ceratite formation:

India Geol. Survey Mem., Palaeontologia Indica, 13th

ser., Salt Range fossils, vol. 2, p. 142. 

1902. Aspidiies (part). Frech, Die Dyas: Lethaea geognostica,

Toil 1, Das Palaeozoicum, Band 2, Lief. 4, p. 637. 

1905. Clypites. Hyatt and Smith, The Triassic cephalopod

genera of America: U. S. Geol. Survey Prof. Paper 40,

p. 103.

Type: Clypites typicus Waagen. 25

Involute, laterally compressed, deeply embracing, 

inner whorls concealed by the outer; umbilicus narrow; sides flattened; venter flattened, narrow, with 

sharp abdominal shoulder angles, which may even 

almost form lateral keels bordering an abdominal 

furrow. Surface smooth, except the faint radial folds 

and striae. Septa ceratitic, external lobe divided by a 

broad saddle, which is broken up by adventitious lobes 

and saddles; first lateral lobe strongly developed; 

second lateral lobe in some specimens not differentiated, auxiliary series long, consisting of small, 

irregular lobes and saddles, as in Aspidites, but usually 

simpler than in that genus.

Clypites is probably no more than a subgenus under 

Hedenstroemia Waagen, but in Hedenstroemia both the 

adventitious and the auxiliary series of lobes and 

saddles are much more individualized. It has some 

resemblance to Aspenites Hyatt and Smith, but this 

genus has a sharp venter, with a keel, and is much 

more compressed laterally. Aspenites, however, seems 

to be closely related to Prodromites Smith and Weller, 

of the Mississippian (lower Carboniferous), which may 

be a connecting link between them and Beloceras, 

whereas Clypites and Hedenstroemia seem to belong to 

the Meekoceratidae.

Clypites is known only from the Lower Triassic 

Ceratite formation, of the Salt Range in India, and

« Waagon, W., Fossils from the Ceratite formation: India Oeol. Survey Mem., 

Valaeontologia Indica, 13tli ser., Salt .Range fossils, vol. 2, p. 143, pi. 21, figs. 7a, b, 

J805.

Alpheus Hyatt found one species in the Lower Triassic 

Meekoceras zone of the Aspen Ridge, southeastern 

Idaho.

Hedenstroemia (Clypites) tenuis Hyatt and Smith

Plate 1, Figures 4-^8

1905. Clypites tenuis. Hyatt and Smith, The Triassic cephalopod genera of America: U. S. Geol. Survey Prof. Paper 

40, p. 103, pi. 1, figs. 4-8.

Form involute, discoidal, laterally compressed, 

deeply embracing. Whorl high and narrow, with 

flattened sides, and narrow-channeled venter with 

biangular margins. Umbilicus closed. Surf ace of cast 

smooth, shell unknown.

Septa lanceolate, with auxiliary, lateral, and adventitious series. The external lobe is divided by a 

small siphonal notch into two short ventrals; the 

adventitious lobes consist of a single pair of serrated 

lobes; the two laterals are broader, longer, and more 

distinctly serrated; the auxiliary series consists of 

several short, pointed lobes, with broadly rounded 

saddles.

In youth the venter is biangular, without the channel; the ventral lobe is undivided, thus forming, with 

the two adventitious lobes, a trifid external.

The septa are simpler than on any of the species 

described by Waagen, but the resemblance is sufficient 

to class them in the same genus. This species has a 

considerable resemblance to Aspenites Hyatt and 

Smith, but differs in its biangular instead of acute 

venter. It is not impossible that Clypites tenuis may 

be the young of Hedenstroemia kossmati, but the writer 

has not had at his disposal sufficient material to show 

the intergradation of the forms.

Horizon and locality: In the Meekoceras zone, about 

9 miles east of Soda Springs, Idaho, in Wood Canyon, 

near the divide, associated with Meekoceras gracilitatis, 

and M. mushbachanum. Collected by Alpheus Hyatt, 

1888.

Family HUNGARITIDAE

Forms involute, laterally compressed, discoidal, 

venter narrow, and surmounted by a keel. Septa 

ceratitic. Surface either smooth or ornamented with 

folds or ribs.

The Hungaritidae have usually been regarded as a 

subfamily of the Ptychitidae but differ from that 

group in having evolute, discoidal young, whereas the 

Ptychitidae are invariably subglobose in the young 

stages. The Hungaritidae have usually been regarded 

as Leiostraca, in spite of their close resemblance to 

Ceratites, but Arthaber 26 has shown that the group is 

inseparable from the Ceratitoidea.

The Hungaritidae are known first from the Permian 

of Armenia, where they are represented by Hungarites

23 Arthaber, O. von, Das jiingere Palaeozoicum aus der Araxes-Enge bei Djulfa: 

Beitr. Palaontologie Oesterr.-Ungarns u. des Orients, Band 12, p. 220. 1900.
80 LOWER TRIASSIC AMMONOIDS OF NORTH AMERICA

and Otoceras, both of which genera occur also in the 

Triassic, the former being especially characteristic of 

the Middle Triassic and the latter not being found in 

later beds than the very lowest horizon of the Triassic. 

In America the family is represented by six genera 

Inyoites Hyatt and Smith, Pseudharpoceras Waagen, 

and Dalmatites Kittl in the Lower Triassic, and 

Plungarites, Longobardites, Dalmatites, and Eutomoceras 

in the Middle Triassic.

Genus INYOITES Hyatt and Smith

1905. Inyoites. Hyatt and Smith, The Triassic cephalopod

genera of America: U. S. Geol. Survey Prof. Paper 40,

p. 134. 

1913. Inyoites. Diener, Triassic faunae of Kashmir: India Geol.

Survey Mem., Palaeontologia Indica, new ser., vol. 5,

No. 1, p. 71. 

1922. Vishnuites (part). Welter, Die Ammoniten der Unteren

Trias von Timor: Palaeontologie von Timor, Lief. 11,

Abh. 19, p. 137.

Type: Inyoites oweni Hyatt and Smith.

Body chamber long, comprising an entire volution; 

form compressed, evolute, little embracing; wide, 

shallow umbilicus, flattened sides, acute venter with 

high hollow keel. Strong lateral ribs, which run 

straight from the umbilical shoulder toward the venter..

Septa ceratitic, consisting of rounded entire saddles 

and serrated lobes. The external lobe is divided by a 

siphonal saddle; the two principal laterals are of about 

the same size as the external, and there is a single 

serrated auxiliary. The long body chamber, the 

lateral ribs, and the high keel resemble Eutomoceras, 

but that genus is involute and has knots on the lateral 

ribs.

This genus has a certain resemblance to Clinolobus 

Gemmellaro, from the Permian of Sicily, but differs 

in its lateral sculpture and ceratitic lobes.

Inyoites is classed with the Hungaritidae on account 

of its evolute form, ceratitic septa, and acute venter; it 

differs from Hungarites in the possession of a long body 

chamber and high hollow keel and in lacking the abdominal shoulder angles. This genus is at present 

represented by a single species in the Lower Triassic 

Meekoceras zone of the Inyo Range, Inyo County, 

Calif.; by Inyoites kashmiricus Diener, from the 

Himalayas; by Inyoites (Vishnuites} discoidalis Welter, 

from Timor; and by an undescribed species from the 

Meekoceras beds of Svalbard.

Inyoites oweni Hyatt and Smith

Plate 6, Figures 1-16; Plate 40, Figures 1-8; Plate 69, 

Figures 1-9

1905. Inyoites oweni. Hyatt and Smith, The Triassic cephalopod 

genera of America: U. S. Geol. Survey Prof. Paper 40, 

p. 134, pi. 6, figs. 1-16; pi. 69, figs. 1-9; pi. 78, figs. 1-8.

Laterally compressed, evolute, discoidal. Whorls 

thin, flattened, with acute venter and high hollow keel. 

Little embracing and not deeply indented by the inner

volutions. Umbilicus wide and shallow, exposing the 

inner whorls. The height of the whorl is twice the 

width and about one-third of the entire diameter. The 

indentation or involution is one-fourth of the height. 

The width of the umbilicus is one-third of the total 

diameter.

The surface is ornamented with fine strong lateral 

ribs that run from the umbilicus straight up the sides 

and disappear below the base of the keel and also with 

fine straight radial striae that run higher up on the 

sides than the ribs.

The septa are ceratitic, saddles all rounded and 

entire, lobes all distinctly serrated. The external lobe 

is divided by a small siphonal saddle, the first and 

second laterals are of about the same size as the external; 

the auxiliary lobe is smaller but still serrated. The 

body chamber is long, at least one revolution.

The young of this species are robust, with low evolute 

whorls and coarse lateral ribs.

Horizon and locality: Inyoites oweni was found by 

Walcott in the Lower Triassic Owenites sub zone of the 

Meekoceras zone of the Inyo Range, on the old McAvoy trail, 1% miles above Union Spring, east side of 

Owens Valley, about 3 miles east of the Reward mill, 

and about 15 miles southeast of Independence, Inyo, 

County, Calif. Tins species was associated with Meekoceras gracilitatis, M. mushbachanum, Pseudosageceras 

multilobatum, and many other forms characteristic of 

the Lower Triassic.

Genus DALMATITES Kittl

1903. Dalmatites. Kittl, Die Cephalopoden der oberen Werfener Schichten von Mud in Dalmatien: K.-k. geol. 

Reichsanstalt Wieii Abh., Band 20, Heft 1, p. 72.

1907. Dalmatites. Diener, The fauna of the Himalayan Muschelkalk: India Geol. Survey Mem., Palaeontologia 

Indica, 15th ser., Himalayan fossils, vol. 5, Mem. 2, 

p. 93.

1914. Dalmatites. Smith, The Middle Triassic marine invertebrate faunas of North America: U. S. Geol. Survey 

Prof. Paper 83, p. 58.

Type: Dalmatites morlaccus Kittl, upper Werfen 

beds of Dalmatia.

Form high whorled, laterally compressed, involute, 

narrowly umbilicate Whorls deeply embracing and 

deeply indented by the inner volutions. Venter rises 

sharply to a narrow keel-like ridge, without ventral 

shoulders. Septa ceratitic, with rounded entire saddles and four slightly serrated lobes, external two laterals, and a small auxiliary. Body chamber twothirds of a revolution in length. Dalmatites resembles 

Plungarites but differs in the greater simplicity of the 

septa, the absence of ventral shoulder angles, and the 

weaker sculpture. From Eutomoceras it may be distinguished by the same characters. In general appearance it is closer to Longobardites, but differs in the 

greater simplicity of the septa. The more complex 

Longobardites may have developed out of the simpler
81

Dalmatites by the addition of the auxiliary and the 

beginning of the adventitious series of lobes.

No genus is described in the Permian from which 

Dalmatites may have originated, but the writer has in 

his collection an undescribed species from the lower 

Permian of the Chinati Mountains, of Texas, that has 

all the characters of Dalmatites. Diener has described 

a species from India, from the Muschelkalk.

Horizon and locality: Dalmatites is represented in the 

Triassic of America by four species two from the 

Lower Triassic of Idaho and two D. minutus Smith 

and D. parvus Smith from the Middle Triassic of the 

West Humboldt Range, Nev.

Dalmatites attenuatus Smith, n. sp.

Plate 57, Figures 11-13

Form involute, laterally compressed, rather widely 

umbilicate, with acute venter. Surface with faint 

radial folds. Septa with a small external lobe, two 

larger laterals, and a small auxiliary. The saddles are 

rounded, and weak serrations may be seen on the lobes, 

almost obliterated by weathering.

The height of the last whorl is half the diameter of 

the shell, and the width is one-third of the height. 

The width, of the umbilicus is slightly greater than onethird of the diameter of the shell.

Dalma,tites attenuatus is nearly related to D. morlaccus 

Kittl, of the Tirolites fauna of Dalmatia,27 but is thinner 

and more acute than the European species.

Horizon and locality: Very rare (one specimen) in 

the Tirolites zone of Paris Canyon, 1 mile west of 

Paris, Idaho; associated with Tirolites harti, T. 

pealei, T. knighti, and other forms. It was also found 

in the Oiuenites subzone of the Meekoceras zone at the 

Phelan ranch, mouth of Cottonwood Canyon, east 

side of the Ruby Range, Nev., about 70 miles south 

of Wells; associated with Meekoceras gracilitatis, 

Owenites koeneni, Inyoites oweni, Lanceolites bicarinatus, 

Pseudosageceras multilobatum, and other forms.

Dalmatites richardsi Smith, n. sp. .

Shell small, involute, laterally compressed, deeply 

embracing; whorls high, with flattened sides, distinct 

ventral shoulder, and sharp keel ridge. Surface 

nearly smooth. Septa ceratitic, with rounded saddles 

and. four well-developed serrated lobes; the auxiliary 

is followed by a short series of serrations toward the 

umbilical suture.

The height of the outer whorl is half the diameter of 

the shell, and the width is one-third of the height; 

the width of the umbilicus is one-sixth of the diameter 

of the shell. The outer whorl embraces nearly all of 

the inner and is indented to nearly half the height.

87 Kittl, Ernst, Die Cephalopoden der oberen Werfener Schichten von Mu6 in 

Damnation: K.-k. geol. Roichsaustalt Wien Abh., Baud 20, Heft 1, p. 73, pi. 4, flgs. 

4-7, 1903.

Dalmatites richardsi is closely related to D. attenuatus, differing in its slightly more robust whorl, distinct 

shoulders, and more complex septa.

Named in honor of Mr. J. E. Richards.

Horizon and locality: Very rare in the Lower 

Triassic Meekoceras zone of southeastern Idaho, at 

locality 1, 5 miles southeast of Grays Lake; associated 

with Meekoceras gracilitatis, M. mushbachanum, Flemingites cirratus, F. russelli, Cordillerites angulatus, 

Lanceolites compactus, Aspenites acutus, Hedenstroemia 

kossmati, Pseudosageceras multilobatum, and other 

forms.

Genus PSEUDHARPOCERAS Waagen

1895. Pseudharpoceras. Waagen, Fossils from the Ceratite 

formation: India Geol. Survey Mem., Palaeontologia 

Indica, 13th ser., Salt Range fossils, vol. 2, p. 130.

1911. Tropiceltites (part). Arthaber, Die Trias von Albanien: 

Beitr. Palaontologie Oesterr.-Ungarns u. des Orients, 

Band 24, p. 26S.

Type: Pseudharpoceras spiniger Waagen, 28 from the 

Lower Triassic equivalent of the Columbites zone in the 

Salt Range of India.

Waagen described this genus as evolute, widely 

umbilicate, with falciform ribs, ventral keel bordered 

by furrows, and a few knobs or incipient spines on the 

ribs. Septa very simple, with but a single lateral lobe, 

whether serrated or goniatitic could not be ascertained. 

He compared it with Tropites of the Upper Triassic 

and with Harpoceras of the Lower Jurassic but had no 

definite idea of its affinities.

Arthaber 29 described "Tropiceltites" praematurus, 

from the Lower Triassic Columbites zone of Albania, 

which is not a Tropiceltites and evidently belongs to 

Pseudharpoceras.

A very similar species occurs in the Columbites zone 

of Idaho and in the same association as in Albania. 

All three are evidently aberrant members of the 

Hungaritidae, and all occur at the same horizon and 

in the same general faunal association. We must 

therefore retain Waagen's genus, however unsatisfactorily founded and described, for it turns out to be 

an interregional index for the Columbites zone of the 

Lower Triassic.

Pseudharpoceras idahoense Smith, n. sp.

Plate 49, Figures 17-19

Shell small, evolute, little embracing, whorls subrectangular in section, with abrupt umbilical and ventral shoulders, strong ventral keel bordered by furrows, 

and sharp lateral falciform ribs. Septa with three 

external lobes and a long internal antisiphonal lobe 

flanked by a short lateral. Whether the septa are 

ceratitic or goniatitic could not be determined on the

» Waagen, W., op. cit., p. 130, pi. 21, flg. 1.

28 Arthaber, O. von, Die Trias von Albanien: Beitr. Palaontologie Oesterr.- 

Ungarns u. des Orients, Band 27, p. 268, pi. 24, flgs. 9, 10, 1914.
82 LOWER TRIASSIC AMMONOIDS OF NORTH AMERICA

two specimens found; nor could the length of the body 

chamber be ascertained.

Pseudharpoceras idahoense is closely related to P. 

spiniger Waagen,30 of the upper part of the Lower 

Triassic of India, differing in its broader and lower 

whorl. It is also more robust than P. praematurum 

Arthaber, 31 from the Lower Triassic Columbites zone 

of Albania, but is sufficiently similar to be placed in 

the same genus.

Horizon and locality: Very rare in the Lower 

Triassic Columbites zone of southeastern Idaho, at 

Paris Canyon, 1 mile west of Paris; associated with 

Meekoceras pilatum, M. curticostatum, M. sanctorum, 

Columbites parisianus, C. spencei, Ophiceras spencei, 

0. jacksoni, and Pseudosageceras multilobatum in a 

fauna certainly related to those of the Columbites zone 

of Albania and of the Olenek River in northern Siberia.

Family CERATITIDAE

Form usually evolute but involute in some groups; 

laterally compressed, robust. Surface usually ornamented with ribs or spines and in some forms with 

ventral keels. Body chamber short in most genera, 

but in a few it is long. Septa ceratitic in nearly all 

genera but goniatitic in some primitive and in some 

reversionary genera; ammonitic in some highly specialized forms.

The Ceratitidae formerly included all ammonites 

with ceratitic septa, but it was gradually found out 

that most Triassic families contained genera with this 

sort of septation, and so the group was finally restricted 

to those in the development series of Ceratites nodosus. 

Even with this restriction the family has been large 

and unwieldy, for many genera that have little kinship with the type resemble it greatly, and many others 

that are closely related to it genetically do not resemble 

it at all. The classification of this family therefore 

can not be based on mere resemblance, but on development series and on ontogenic studies of the various 

genera.

The most primitive members of the family are all 

evolute, little-embracing forms with very simple 

septa, and the young stages of all the genera, except 

the most specialized, are of this type. This indicates 

that the family radicle is to be sought in an evolute 

form with simple septa. More than this, all the 

earliest known members of the family have little 

sculpture, and the adolescent stages of most genera, 

except the highly specialized later forms, are nearly 

smooth. This indicates that this family had a common origin with the Meekoceratidae and the Hungaritidae, in some genus with the characters of Lecanites. Although the later genera of all three families 

can easily be distinguished from one another, the earlier

30 Waagen, W., op. cit. (Fossils from the Ceratite formation), p. 130, pi. 21, fig. 1.

31 Arthaber, G. von, op. cit. (Die Trias von Albanien), p. 268, pi. 24, figs. 9, 10.

ones can not; and, further, the young stages of all 

three groups are very similar, which is sufficient justtification for placing all three in the suborder Ceratitoidea.

The most elaborate and systematic classification of 

the Ceratitidae has been attempted by Mojsisovics,32 

who divided the family as follows:

Subfamily Dinaritinae:

Phylum 1. Dinaritea, containing Dinarites, Ceratites, and 

Arpadites, with a number of subgenera or subordinate 

genera.

Phylum 2. Heraclitea, containing Pleraclites and Cyrtopleurites.

Phylum 3. Orthopleuritea, containing Polycyclus, Choristoceras, Rhabdoceras, and Cochloceras. 

Subfamily Tirolitinae:

Phylum 1. Tirolitea, containing Tirolites and Badiotites.

Phylum 2. Distichitea, containing Distichites and Ectolcites.

Phylum 3. Trachyceratea, containing Trachyceras, Eremites, Sandlingites, Clydonites, and Sirenites.

The Dinaritinae were supposed to develop out of 

Dinarites and the Tirolitinae out of Tirolites, and 

both were thought to have come from Xenodiscus or 

some related genus. This subdivision of the family 

is, then, not merely a convenient arrangement but 

an attempt at a phylogenic classification. All the 

later work of Diener, Waagen, and others has substantiated the classification in most essentials, although some of the details must be modified.

The writer has studied the ontogeny of Danubites, 

Ceratites, Arpadites, and Clionites, of the Dinaritinae 

and has found the young stages to be like Paratirolites, so it becomes probable that this is the ultimate 

family radicle of both divisions of the Ceratitidae. 

The parent form of Paratirolites must have been 

Xenodiscus and ultimately Lecanites, which differs 

only very slightly from the earlier species of Dinarites 

and Danubites. Lecanites was probably derived from 

Paralecanites of the Permian and Lower Triassic, 

through which the Ceratitidae were probably derived 

from the Prolecanitidae of the Carboniferous. By the 

Prolecanitidae the writer does not' mean the phylum 

or. suborder as the term has been used by Karpinsky 

and Haug but the group of Prolecanites.

At the time Mojsisovics selected Xenodiscus as the 

probable radicle of the Ceratitidae it was the only 

Permian ammonite genus known that could possibly 

have been the ancestral form. The later work of 

Diener and Waagen has shown that the characters 

of this genus and its kindred form Xenaspis, as known 

in the Lower Triassic, are too highly specialized for 

either one to have been the ultimate family radicle 

but that there are other similar but more primitive 

groups in the lower beds of the Triassic that may

32 Mojsisovics, E. von, Die Cephalopoden der Hallstatter Kalke: K.-k. geol. 

Reichsanstalt Wien Abh., Band 6, HSlfte 2, p. 395, 1893.
CERATITIDAE 83

with more probability be regarded as the ancestors . 

of the Ceratitidae.

No Ceratitidae are as yet known certainly below 

the Lower Triassic. Lecanites is now known in the 

Permian, and Xenodiscus, Xenaspis, Hungarites, and 

Otoceras, which must have developed out of Lecanites, 

are known in the upper Permian. Our knowledge of 

the ammonites of the Carboniferous is still very fragmentary, and until more discoveries are made all our 

classifications will stand on an insecure basis. At 

present the ontogeny of the principal genera is the 

only criterion, and that is uncertain, because of the 

imperfection of the material and its scarcity.

In America the Ceratitidae are represented in the 

Lower Triassic by Danubites, and Tirolites. 

Genus TIROLITES Mojsisovics

1878. Tiroliles. Mojsisovics, Dolomitriffe von Sudtirol und 

Venetien, Wien, p. 43.

1879. Tiroliles. Mojsisovics, Vorlixufige kurze Uebersicht der 

Ammoniten-Gattungen der Mediterranen und Juvavischen Trias: K.-k. geol. Reichsanstalt Wien Verb., 

p. 138.

1882. Tirolites. Mojsisovics, Die Cephalopoden der Mediterranen Triasprovinz: K.-k. geol. Reichsanstalt Wien 

Abh., Band 10, p. 64.

1893. Tirolites. Mojsisovics, Die Cephalopoden der Hallstiitter 

Kalke: K.-k. geol. Reichsanstalt Wien Abh., Band 6; 

Hfilfte 2, p. 588.

1902. Tiroliles. Mojsisovics, Die Cephalopoden der Hallstiitter 

Kalke: K.-k. geol. Reichsanstalt Wien Abh., Band 6, 

Supplement-Heft, p. 324.

1903. Tirolites. Kittl, Die Cephalopoden der oberen Werfener 

Schichten von Mu<$ in Dalmatien: K.-k. geol. Reichsanstalt Wien Abh., Band 20, Heft 1, p. 29.

1905. Tiroliles. Hyatt and Smith, The Triassic cephalopod 

genera of America: U. S. Geol. Survey Prof. Paper 40, 

p. 158.

1911. Tirolites. Arthaber, Die Trias von Albanien: Beitr. 

Palaontologie Oesterr.-Ungarns u. des Orients, Band 24, 

p. 250.

Type: " Ceratites" idrianus Hauer. 33

Evolute, little embracing, robust, laterally compressed whorls, with wide, shallow umbilicus. Venter 

flattened and without central furrow or other sculpture. Sides ornamented with ribs, which end on the 

square abdominal shoulders in long spines. Body 

chamber short. Septa simple; external lobe divided 

by a shallow siphonal prominence; the two branches of 

this lobe are goniatitic. The lateral lobe is broad and 

shallow and may be weakly serrated, although in some 

forms it is goniatitic. An auxiliary lobe may be faintly 

indicated on the umbilical shoulder

This genus was regarded by Mojsisovics as the radicle 

of the Tirolitinae, subfamily of the Ceratitidae, in33 Hauor, .F. von, Die Cephalopoden aus der Untercn Trias der Alpen: K. AkadWiss. Wion Siteungsbcr., Band 52, p. 010, pi. 1, figs. 4, 5, 1865. Mojsisovics, E. von. 

Die Coplmlopoden der Mediterranen Triasprovinz: K.-k.-geol. Reichsanstalt Wien 

Abh., Band 10, p. 07, pi. J, fig. 1, 1882.

eluding Tirolites, Balatonites, Trachyceras, and Sirenites as its chief representative. This view is no longer 

held, and the writer regards both Tirolites and Dinarites 

as degenerates rather than radicles.

Tirolites s. s. is characteristic of the Werfen beds of the 

Lower Triassic of the Mediterranean region and occurs 

in the Lower Triassic also in Idaho. In America it is 

represented by the subgenus Metatirolites Mojsisovics, which occurs in the Upper Triassic of California, 

and by one species of the Tirolites spinosi, in the 

Middle Triassic of California, and by several species 

closely allied to Tirolites cassianus in the Tirolites zone 

of the Lower Triassic of Idaho.

Tirolites harti Smith, n. sp.

Plate 57, Figures 9, 10

Shell rather large, evolute, widely umbilicate. 

Whorls with flanks sloping outwardly upward from the 

umbilicus, so that the widest part is at the ventral 

shoulders. Venter nearly flat but very gently arched. 

Surface with about 10 coarse spines to a revolution, 

situated on the ventral shoulder.

The height of the last whorl is somewhat greater 

than one-fourth of the diameter of the shell; the 

width is a little more than the height; the width of 

the umbilicus is somewhat less than half the diameter 

of the shell.

Tirolites ha?'ti has a considerable resemblance to 

T. cassianus Quenstedt as figured by Kittl 34 but has a 

broader whorl and fewer spines. It has a much closer 

resemblance to T. haueri Mojsisovics 35 but has the 

spines a little coarser and the whorl a trifle broader. 

However, Kittl 36 figures T. haueri as a broader and 

more robust species than the type description and figures show; he also states that Mojsisovics's figures 

are inaccurate, not being sufficiently broad and robust.

Better material will probably show that Tirolites 

harti is identical with T. haueri, but in default of that 

they must be kept separate for the present, as the 

material from the Tirolites zone of Idaho is rather too 

poor for the identification of interregional species.

Named in honor of James E. Hart.

Horizon and locality: Rather rare in the Tirolites 

zone of the Lower Triassic of Paris Canyon, 1 mile west 

of Paris, Idaho; associated with Tirolites pealei, T. 

knighti, Dalmatites attenuatus, Pentacrinus (Isocrinus} 

smithi, Pugnoides triassicus Girty, and other forms.

Tirolites haueri is a diagnostic species for the Tirolites 

zone of the Werfen beds of the Balkan region.

 34 Kittl, Ernst, Die Cephalopoden der oberen Werfener Schichten von Muc in 

Dalmatien: K.-k. geol. Reichsanstalt Wien Abh., Band 20, Heft J, p. 54, pi. 9, 

figs. 4-0, 1903.

35 Mojsisovics, E. von, Die Cephalopoden der Mediterranen Triasprovinz: K.-k. 

geol. Reichsanstalt Wien Abh., Band 10, p. 71, pi. 3, figs. 2-4,1882. 

1 3<> Kittl, Ernst, op. cit., p. 56, pi. 9, figs. 8-13.
84 LOWER TRIASSIC AMMONOIDS OF NORTH AMERICA

Tirolites illyricus Mojsisovics

Plate 49, Figures 12-16

1882. Tirolites illyricus. Mojsisovics, Die Cephalopoden der 

Mediterranen Triasprovinz: K.-k. geol. Reichsanstalt 

Wien Abh., Band 10, p. 68, pi. 21, fig. 10.

1903. Tirolites illyricus. Kittl, Die Cephalopoden der oberen 

Werfener Schichten von Muc in Dalmatien: K.-k. 

geol. Reichsanstalt Wien Abh., Band 20, Heft 1, p. 48, 

pi. 8, figs. 3, 4, 6, 9.

Shell evolute, discoidal, little embracing, somewhat 

compressed laterally. Umbilicus wide, with abrupt 

shoulders; flanks flattened, ventral shoulders abruptly 

rounded, venter slightly arched. Ornamented with 

fine cross striae of growth, weak lateral folds, and strong 

spines on the ventral shoulders, about 10 to a revolution.

Tirolites illyricus is related to T. harti and T. pealei, 

of the Tirolites zone, but differs in its weaker sculpture, 

more compressed whorl, and less numerous spines.

Horizon and locality: Tirolites illyricus was first 

found in the Balkan region of the Mediterranean 

Province, where it is common in the Werfen Tirolites 

zone. It is very rare in the Columbites zone of the 

Lower Triassic of southeastern Idaho, at the mouth 

of Paris Canyon, 1 mile west of Paris; associated with 

Columbites parisianus, C. spencei, Meekoceras pilatum, 

Ophiceras spencei, and other forms.

Tirolites knighti Smith, n. sp.

Plate 57, Figures 1-4

Shell evolute, little embracing, with wide umbilicus 

and subrectangular whorls, a little higher than wide. 

Surface shows about 30 fine lateral ribs with ventral 

shoulder knots to a revolution. Septa ceratitic, with 

rounded saddles and serrated lobes, of which there are 

three a very short divided ventral, a much longer 

lateral, and small auxiliary on the umbilical shoulder. 

Serrations could not be seen on the auxiliary, although 

they are probably present.

The height of the last whorl is two-sevenths of the 

diameter of the shell; the width is more than fourfifths of the height; the width of the umbilicus is somewhat less than half the diameter of the shell.

Tirolites knighti is very closely related to T. cassianus 

Quenstedt, as figured by Kittl,37 but Kittl's figures are 

not like those of Mojsisovics,38 being presumably based 

on better specimens. However, when the European 

authorities disagree as to specific characters, the writer 

does not care to identify American forms with them, 

especially as the American material is not sufficiently 

well preserved for such an attempt.

Horizon and locality: Rather rare in the Lower Triassic Tirolites zone in Paris Canyon, 1 mile west of

s ? Kittl, Ernst, op. cit. (Cephalopoden der oberen Werfeuer Schichten von Muc), 

p. 54, pi. 9, figs. 4-6.

38 Mojsisovics, E. von, op. cit. (Die Cephalopoden der Mediterranen Triasprovinz), p. 70, pi. 2, figs. 4-8; pi. 81, fig. 3.

Paris, Idaho; associated with Tirolites harti, T. pealei, 

Dalmatites attenuatus, Pentacrinus (Isocrinus} smithi, 

Pugnoides triassicus Girty, and other forms.

Tirolites pealei Smith, n. sp.

Plate 57, Figures 5-8

Form evolute, widely umbilicate, little embracing, 

with whorls higher than wide. Surface shows numerous lateral ribs and marginal spines, which are coarser 

and fewer in adolescence; at maturity the marginal 

spines are nearly obsolete, and the ribs become finer 

and more numerous.

The height of the last whorl is somewhat less than 

one-third of the diameter of the shell; the width is 

slightly greater than two-thirds of the height; the 

width of the umbilicus is a little less than half the diameter of the shell.

Tirolites pealei is related to T. knighti but is more 

compressed laterally. It has a much greater resemblance to T. smiriagini Auerbach, of the Tirolites beds 

of the Balkan region, as figured by Mojsisovics 39 

and by Kittl,40 differing from these descriptions and 

figures in no essential. But the material from the 

Tirolites zone of Idaho is hardly good enough for the 

identification of interregional species, and consequently they are separated until specimens can be 

found which would justify their union.

Named in honor of A. C. Peale.

Horizon and locality: Rather rare in the Lower 

Triassic Tirolites zone in Paris Canyon, 1 mile west 

of Paris, Idaho, associated with Tirolites harti, T. 

knighti, Dalmatites attenuatus, Pentacrinus (Isocrinus] 

smithi, Pugnoides triassicus Girty, and other forms.

Genus DANUBITES Mojsisovics

1893. Danubites. Mojsisovics, Die Cephalopoden der Hallstatter Kalke: K.-k. geol. Reichsanstalt Wien Abh., 

Band 6, pt. 2, p. 398.

1897. Danubites. Diener, Cephalopoda of the Lower Trias: 

India Geol. Survey Mem., Palaeontologia Indica, 15th 

ser., Himalayan fossils, vol. 2, pt. 1, p. 24.

1900. Florianites. Hyatt, Cephalopoda, in Zittel, K. A. von, 

Textbook of palaeontology (translated by C. R. 

Eastman), p. 558.

1902. Danubites. Mojsisovics, Die Cephalopoden der Hallstatter Kalke: K.-k. geol. Reichsanstalt Wien Abh., 

Band 6, Supplement-Heft, p. 323.

1905. Danubites. Hyatt and Smith, The Triassic cephalopod 

genera of America: U. S. Geol. Survey Prof. Paper 

40, p. 163.

1914. Danubites. Smith, The Middle Triassic marine invertebrate faunas of North America: U. S. Geol. 

Survey Prof. Paper 83, p. 75.

Type: "Celtites" floriani Mojsisovics.41

39 Mojsisovics, E. von, op. cit. (Die Cephalopoden der Mediterranen Triasprovinz), p. 73, pi. 81, figs. 1, 2.

40 Kittl, Ernst, op. cit. (Die Cephalopoden der oberen Werfener Schichten von 

Muc), p. 63, pi. 11, fig. 6.

41 Mojsisovics, E. von, Die Cephalopoden der Mediterranen Triasprovinz: K.-k. 

geol. Reichsanstalt Abh., Band 10, p. 145, 1882.
SAGECERATIDAE

Evolute, little embracing, robust whorls, slowly 

increasing in size; umbilicus very wide; shape of 

cross section subquadratic; body chamber short. 

Sculpture of the circumplicate type, consisting of 

simple, rarely bifurcating ribs, running straight from 

the umbilicus up the sides to the abdominal shoulders 

but invariably interrupted on the somewhat rounded 

venter. Occasionally there is a threadlike keel in the 

center of the siphonal area, but this is usually smooth 

and flattened.

Septa ceratitic, an external lobe, two lateral lobes, 

and an auxiliary lobe present. In one species the septa 

seem to remain through life in the goniatitic stage, and 

in others the auxiliary lobe remains entire, but usually 

all four are serrated.

Mojsisovics at first included the type species under 

his genus Celtites, which is characterized by goniatitic 

lobes and long body chamber. Afterward, when its 

characters became better known, he placed it under 

the group of Ceratites obsoleti, for which he established 

the subgenus Danubites, with this species as the type. 

But as this group is not derived from Ceratites and is 

probably not the ancestor of that genus, the writer 

prefers to consider it an independent genus.

Byatt 42 took Celtites floriani as the type of a new 

genus, Florianites, having overlooked the fact that it 

was already used as the type of another genus.

This genus was once thought to be common in the 

Lower Triassic of India, Siberia, Idaho, and California 

and in the Middle Triassic of Siberia, Japan, and 

Nevada. Most of those species have since been assigned to other genera. Danubites strongi is the only 

form described from America that is left to Danubites, 

and. that very doubtfully.

Danubites strongi Hyatt and Smith

Plate 9, Figures 4-10

1905. Danubites strongi. Hyatt and Smith, The Triassic 

cephalopod genera of America: U. S. Geol. Survey 

Prof. Paper 40, p. 165, pi. 9, figs. 4-10.

Evolute, robust, discoidal, somewhat compressed 

laterally, widely umbilicate. Whorls low and increasing slowly in height, covering about half the inner 

volution and indented by it to one-fifth of the height. 

The height of the whorl is a little more than onethird of the diameter of the shell. The umbilicus is 

shallow and wide, being nearly half the total diameter. 

The surface is ornamented only with coarse, rounded, 

straight radial ribs that start from the umbilical 

shoulders and run up the flanks to the rounded abdominal shoulders, where they become obsolete. The 

venter is highly arched, helmet shaped, and smooth.

The septa are ceratitic, the saddles are all rounded 

and entire, and the lobes are serrated. The ventral

<J Hyatt, Alpheus, Cephalopoda, in Zittel, K. A. vou, Textbook of palaeontology, 

(translated by C. R. Eastman), p. 558, 1900.

lobe is divided by a short siphonal saddle into two 

very short, narrow branches; the first lateral lobe is 

broader and longer, the second lateral about the size 

of the external, and there is a small shallow entire 

auxiliary on the umbilical shoulders. The body 

chamber seems to have been short, but no perfect 

specimens were found to illustrate this point.

Horizon and locality: Lower Triassic Meekoceras 

zone, Owenites subzone, of the Inyo Range, east side 

of Owens Valley, \%, miles east of Union Springs and 

3 miles east of Skinner's ranch, on the McAvoy trail 

leading over Union Wash to Salinas Valley, about 15 

miles southeast of Independence, Inyo County, Calif.; 

associated with Meekoceras gracilitatis, Owenites koeneni, Pseudosageceras multilobatum, and many other 

forms characteristic of the Lower Triassic.

BEIOCERATOIDEA 

Family SAGECERATIDAE

Involute, laterally compressed, discoidal. Short 

body chamber; narrow venter, either flattened with 

angular margins or channeled or with central keel. 

Surface smooth or ornamented only with spiral ridges 

or low folds. Septa lanceolate, either dicranidian, 

prionidian, or ammonitic, but invariably with adventitious lobes.

This family probably connects with Beloceras Hyatt, 

of the Devonian, but the only intermediate genus yet 

known is Prodromites Smith and Weller,43 from the 

Mississippian ("Lower Carboniferous") of America. 

In the Lower Triassic this family is represented by 

As2>enites Hyatt and Smith, Sageceras Mojsisovics, 

and Pseudosageceras Diener; so that many members of 

the family may be looked for in the Permian. In the 

Middle and Upper Triassic the chief member is 

Sageceras.

Genus ASPENITES Hyatt and Smith

1905. Aspenites. 'Hyatt and Smith, The Triassic cephalopod

genera of America: U. S. Geol. Survey Prof. Paper 40,

p. 95. 

1917. Aspenites. Diener, Ueber Ammoniten mit Adventivloben: K. Akad. Wiss. Wien Denkschr., Band 93, p. 172. 

1922. Aspenites. Welter, Die Ammoniten der Unteren Trias

von Timor: Palaeontologie von Timor, Lief. 11,

Abh. 19, p. 97.

Type: As%)enites acutus Hyatt and Smith.

Form compressed, involute, deeply embracing, discoidal ; sides flattened, abdomen acute and surmounted 

by a keel, umbilicus closed. Surface ornamented with 

fine, strong radial folds.

Ventral lobe narrow and short, divided by a short 

siphonal notch; that is, one small adventitious lobe on 

each side; three laterals, which are larger than the 

others and distinctly serrated. Following these lobes

< 3 Smith, J. P., and Weller, Stuart, Prodromites, a new ammonite genus from the 

Lower Carboniferous: Jour. Geology, vol. 9, p. 255, 1901.
86 LOWER TRIASSIC AMMONOIDS OF NORTH AMERICA

is a short auxiliary series of goniatitic lobes. The internal septa consist of a long antisiphonal lobe, two 

laterals, and a long series of internal auxiliaries, all 

serrated. The length of the body chamber is unknown.

Aspenites resembles Clypites Waagen but differs 

from that genus in the simpler lobes and in the possession of a keel. It shows also a certain resemblance to 

Prodromites Smith and Weller from the Mississippian 

but is entirely too simple to have been a descendant of 

that highly specialized genus. Its form and septa suggest a derivation from Timanites of the Devonian.

Aspenites is known at present from the Lower Triassic Meekoceras zone of southeastern Idaho and of the 

Inyo Range, Inyo County, Calif.; and from the Owenites zone of Timor. Three species have been found 

A. acutus, A. obtusus, and A. laevis.

Aspenites acutus Hyatt and Smith

Plate 2, Figures 9-13; Plate 3, Figures 1-5; Plate 30, Figures 

1-26; Plate 60, Figures 4-6

1905. Aspenites acutus. Hyatt and Smith, The Triassic cephalopod genera of America: U. S. Geol. Survey Prof. 

Paper 40, p. 96, pi. 2, figs. 9-13; pi. 3, figs. 1-5.

1917. Aspenites acutus. Diener, Ueber Ammoniten mit Adventivloben: K. Akad. Wiss. Wien Denkschr., Band 93, 

p. 172.

1922. Aspenites layeriformis. Welter, Die Ammoniten cler Unteren Trias von Timor: Palaeontologie von Timor, 

Lief. 11, Abh. 19, p. 97, pi. 155, figs. 6-8, and text .fig. 7.

Form discoidal, involute, deeply embracing, laterally compressed. Whorls high and narrow, with flattened sides, and acute venter. Umbilicus closed. The 

height of the last whorl is nearly three-fifths of the total 

diameter of the shell; its width is somewhat more than 

one-third of its height, and it is indented to about 

three-eighths of its height by the inner volution.

The surface is nearly smooth but ornamented with 

fine radial folds, visible on the cast, stronger near the 

umbilicus, and becoming obsolete high upon the 

flanks.

The septa are lanceolate, consisting of an adventitious series, a lateral, and an auxiliary series. The 

saddles are all entire and rounded; the lobes of the 

adventitious and of the auxiliary series are simple and 

pointed, whereas the laterals are serrated. The external lobe consists of a short bifid ventral, flanked by a 

single longer and pointed adventitious lobe on each 

side. The first lateral is short and slightly serrated, 

the second is longer and broader, the third short like 

the first but broader. The auxiliary Series consists of 

two or three short-pointed lobes with broadly rounded 

saddles.

The form and the septa suggest a derivation from 

Timanites Mojsisovics of the Devonian, as described 

by Holzapfel. 45 Aspenites differs from Timanites in

45 H'olzapfel, E., Die Cephalopoden des Domanik im siidlichen Timan: Com. 

geol. I St.-P6tersbourg] Mem., vol. 12, No. 3, 1899.

the development of the adventitious series and the serration of the laterals, but its young stages are remarkably like the mature forms of the Devonian genus. 

Timanites is placed by some writers in the Prolecanitidae, by others in the Primordialidae, but its true position will probably be found to be along with Beloceras, 

as an offshoot from the Primordialidae.

Horizon and locality: Aspenites acutus was found by 

Alpheus Hyatt in the Lower Triassic Meekoceras zone 

in Wood Canyon, near Soda Springs, Idaho, and by 

J. P. Smith in the Owenites subzone of the Meekoceras 

zone in Union Wash, near Union Spring, in the Inyo 

Range, about 15 miles southeast of Independence, 

Inyo County, Calif. Aspenites layeriformis Welter 46 

can be at most only a variety of A. acutus. This 

form was described by Welter from the Owenites zone 

of Timor, in very much the same association as in 

America.

Aspenites laevis Welter

Plate 28, Figures 28-33

1922. Aspenites laevis. Welter, Die Ammoniten der Unteren 

Trias von Timor: Palaeontologie von Timor, Lief. 11, 

Abh. 19, p. 99, pi. 155, figs. 4, 5, and text fig. 8.

Involute, laterally compressed, narrowly umbilicate, 

with gently convex flanks and high, narrow, sharp 

venter, with high ventral keel. Surface nearly smooth. 

Septa with entire saddles and long tongue-shaped 

lobes, mostly serrated. There is a series of four 

adventitious lobes, reducing in size toward the siphon; 

two laterals, of which the outer is much the larger; 

and a long series of auxiliaries.

Aspenites laevis is closely related to A. acutus, differing in the higher ventral keel and much more complicated septa.

Horizon and localit}^: Very rare in the Meekoceras 

zone of southeastern Idaho, at locality 1, 5 miles 

southeast of Grays Lake; at locality 3, head of Wood 

Canyon, Aspen Mountains, 9 miles east of Soda 

Springs. It was first described from the Owenites 

zone of the Lower Triassic of Timor, in the East 

Indies, in very much the same association as in Idaho.

Aspenites obtusus Smith, n. sp..

Plate 31, Figures 8-10

Form laterally compressed, high-whorled, involute, 

with closed umbilicus, flat sides, and narrow, blunt' 

venter, rounded and without keels or furrow. Surface 

nearly smooth, with faint undulations and fine 

growth lines. Septa with rounded entire saddles and 

serrated lobes. The adventitious series is short, consisting of two small lobes; the first lateral is broad and 

shallow; the second lateral much smaller; the auxiliary

"Welter, O. A., Die Ammoniten der Unteren Trias von Timor: Palaeontologie 

von Timor, Lief. 11, Abh. 19, p. 97, pi. 155, figs. 6-8, and text fig. 7, 1922
SAGECERATIDAE 87

series consists of a row of hardly differentiated rudimentary lobes.

Aspenites obtusus differs from A. acutus in its more 

robust form, blunt venter, and simpler septa.

Horizon and locality: Very rare in the Lower Triassic 

Meekoceras zone, of locality 5, 1 mile east of Hot 

Springs, at the north end of Bear Lake, Bear Lake 

County, Idaho; associated with Meekoceras gracilitatis, M. mushbachanum, Flemingites russelli, Hedenstroemia kossmati, Pseudosageceras multilobatum, Juvenites dieneri, J. kraffti, Cordillerites angulatus, Paranannites aspenensis, Tliermalites thermarum, Lanceolites compactus, and many other species characteristic 

of this horizon.

Genus PSEUDOSAGECERAS Diener

1895. Pseudosageceras. Diener, Triadische Cephalopoden.

faunen der ostsibirischen Kiistenprovinz: Com. g6ol-

[St.-P6tersbourg] Mem., vol. 14, p. 28, No. 3. 

1902. Pseudosageceras. Frech, Lethaea geognostica, Teil 1,

Das Palaeozoicum, Band 2, Lief. 4, p. 659. 

1905. Pseudosageceras, Noetling, Untersuchungen ueber den

Ban der Lobenlinie von Pseudosageceras multilobatum

Noetling: Palaeontographica, Band 51, pp. 155-260. 

1905. Pseudosageceras. Hyatt and Smith, The Triassic eephalopod genera of America: U. S. Geol. Survey Prof.

Paper 40, p. 98.

1908. Pseudosageceras. Arthaber, Ueber die Entdeckung von 

Untertrias in Albanien: Geol. Gesell. Wien Mitt., 

Band 1, p. 279.

1909. Pseudosageceras. Krafft and Diener, Lower Triassic

Cephalopoda from Spiti, Malla Johar, and Byans:

India Geol. Survey Mem., Palaeontologia Indica, 15th

ser., vol. 6, Mem. 1, p. 145. 

1911. Pseudosageceras. Arthaber, Die Trias von Albanieu:

Beitr. Palaontologie Oesterr.-Ungarns u. des Orients,

Band 24, p. 201. 

1917. Pseudosageceras. Diener, Ueber Ammoniten mit Adventivloben: K. Akad. Wiss.- Wien Denkschr., Band

93, p. 173. 

1922. Pseudosageceras. Welter, Die Ammoniten der Unteren

Trias von Timor: Palaeontologie von Timor, Lief. 11,

Abh. 19, p. 94. 

1929. Pseudosageceras. Mathews, The lower Triassic cephalopod fauna of the Fort Douglas area, Utah: Walker

Mus. Mem., vol. 1, No. 1, p. 3.

Type: Pseudosageceras sp. indet. Diener. 47 

Shell compressed, involute, discoidal, deeply embracing1 , umbilicus closed, sides flattened; venter narrow 

and angular, with a low, sharp keel surmounting the 

venter. Surface smooth on all the species now known 

in Asia, Europe, and America. Septa consisting of 

numerous long and narrow lobes and saddles; the saddles are all entire, and the lobes all divided; near the 

venter there is a series of shorter adventitious lobes, 

chiefly bifid, and on the flanks a series of several laterals, chiefly trifid but with secondary divisions. 

Below the chief laterals is a series of bifid auxiliaries 

outside the umbilicus.

<' Dicnor, Carl, Triaclisclic Ccphalopodcnfaunon dor ostsibirischen Kiistenprovinz: Coin. g6ol. [St.-Pctersbourg] Mem., vol. 14, No. 3, p. 28, pi. 1, fig. 8, 1895.

This genus resembles Sageceras Mojsisovics but has 

more complex septa and can not possibly be the 

ancestor of it, for in Sageceras the lobes are invariably 

bifid, the trifid stage never being reached. A near 

relative and possible ancestor of Pseudosageceras may 

be found in Prodromites Smith and Weller,48 from the 

Mississippian ("Lower Carboniferous"); which may 

be a connecting link with Beloceras Hyatt, of the Devonian, for Prodromites has the same involute, compressed, acute form, and the numerous serrated lobes 

with a long auxiliary series, but it has not developed 

the typical adventitious lobes characteristic of Beloceras 

and Pseudosageceras. A more probable link between 

Beloceras and Pseudosageceras is Acrocanites Schindewolf,49 type A. multilobatus Schindewolf, from the 

Pericyclus zone of the lower Carboniferous of Germany. 

This form is discussed below under the specific description, in which is also given a discussion of the phylogeny of Pseudosageceras, based on the ontogeny of 

the type species.

Pseudosageceras is known from the Lower Triassic of 

Ussuri Bay, in eastern Siberia; from the Lower Triassic 

of India, and from the corresponding Meekoceras zone 

of the Aspen Ridge in southeastern Idaho and the 

Inyo Range in California; also from the Anasibirites 

subzone of Utah and from the Columbites zone of 

Albania and of Idaho.

Frech assumes that two geologic horizons are represented in the Proptychites beds of Ussuri Bajr and 

that Ussuria and Pseudosageceras came out of Permian 

strata, whereas Meekoceras came out of Lower Triassic 

beds. This assumption is, however, unlikely, for 

the writer has found both Ussuria and Pseudosageceras 

in the Aspen Ridge of Idaho, associated with Meekoceras gracilitatis and numerous other species of Meekoceras and other forms equally characteristic of the 

Lower Triassic. But it is extremely probable that 

both genera will eventually be found in the Permian, 

for the stocks to which they belong are already well 

differentiated in the Carboniferous.

Pseudosageceras multilobatum Noetling

Plate 4, Figures 1-3; Plate 5, Figures 1-6; Plate 25, Figures 

7-16; Plate 60, Figure 32; Plate 63, Figures 1-6

1905. Pseudosageceras multilobatum. Noetling, Untersuchungen 

ueber den Ban der Lobenlinie von Pseudosageceras multilobatum Noetling: Palaeontographica, Band 51, pp. 

183 et seq.

1905. Pseudosageceras intermontamim. Hyatt and Smith, The 

Triassic cephalopod genera of America: U. S.' Geol. 

Survey Prof. Paper 40, p. 99, pi. 4, figs. 1-3; pi. 5, figs. 

1-6; pi. 63, figs. 1, 2.

1906. Pseudosageceras multilobatum. Frech, in Noetling, Die 

asiatische Trias: Lethaea geognostica, Teil 2, Das 

Mesozoicum, Band 1, Trias, pi. 25, figs, la-b; pi. 26, 

figs. 3a-b.

«« Smith, J. P., and Weller, Stuart, op. cit., p. 257.

« Schiiidcwolf, 0. H., Ueber eine Unterkarbonfauna aus Ostthiiringon: Senckenbergiana, Band 4, Heft 1, 2, p. 15, 1922.
88 LOWER TRIASSIC AMMONOIDS OF NORTH AMERICA

1909. Pseudosageceras multilobatum. Krafft and Diener, Lower 

Triassic Cephalopoda from Spiti, Malla Johar, and 

Byans: India Geol. Survey Mem., Palaeontologia Indica, 15th ser., vol. 6, Mem. 1, p. 145, pi. 21, fig. 5.

1911. Pseudosageceras multilobatum. Wanner, Triascephalopoden von Timor und Rotti: Neues Jahrb., Beilage- 

. Band 32, p. 181, pi. 7, fig. 4.

1922. Pseiidosageceras multilobatum. Welter, Die Ammoniten 

der Unteren Trias von Timor: Palaeontologie von 

Timor, Lief. 11, Abh. 19, p. 94, text fig. 3.

1929. Pseudosageceras intermontanum. Mathews, The Lower 

Triassic cephalopod fauna of the Fort Douglas area, 

Utah: Walker Mus. Mem., vol. 1, No. 1, p. 3, pi. 1, 

figs. 18-22.

Not 1908. Pseudosageceras multilobatum. Arthaber, Ueber die 

Entdeckung von Untertrias in Albanien: Geol. Gesell. 

Wien Mitt., Band 1, p. 279, pi. 12, figs. 3a-c. '

Shell compressed, involute, discoidal, deeply embracing, with closed umbilicus and flattened sides, with 

gentle convex curve up to the venter, which is narrow, 

with small furrow and two fine bordering keels. On 

this furrow rests a central keel, which, however, is 

usually broken off.

Septa consisting of numerous lanceolate lobes and 

saddles, the saddles all entire and the lobes mostly 

divided.- Next to the venter is a series of four adventitious lobes on each side of the short undivided ventral, 

of which the first is short and undivided, the second 

longer and bifid, the third bifid, with a secondary 

notch on the upper prong, the fourth unsymmetrically 

bifid, with notches on both prongs; then follows a series 

of two principal lateral lobes, of which the first is unsymmetrically trifid, all the prongs being indented, and 

a second deeply and unsymmetrically bifid. After the 

principal lateral lobes follows a series of six irregular 

auxiliaries, of which the first and third are bifid and the 

others apparently entire. This septation is more complex than on Diener's type species but is of the same 

general character. Also Diener's specimen was very 

imperfect but if better preserved might have shown 

these same characters, so that the two are certainly 

congeneric.

The length of the body chamber is unknown, as all 

the specimens were septate, but imperfect individuals 

115 millimeters in diameter have been found.

Dimensions of a specimen from the Lower Triassic Meekoceras 

zone of Wood Canyon, near Soda Springs, Idaho

Millimeters

Diameter ________________________________ 93

Height of last whorl ______________________ 56

Height of last whorl from the preceding.____ 33

Breadth of last whorl_____________________ 19

Involution._____ _______________________ 23

Width of umbilicus.--.------------------- 2

The whorl is indented to nearly half its height by 

the inner coil, and the greatest breadth lies just opposite this point.

Horizon and locality: Lower Triassic Meekoceras zone 

of Wood Canyon, 9 miles east of Soda Springs, Aspen

Ridge, southeastern Idaho; and the Owenites subzone 

of the same zone on Union Wash, 3 miles east of 

Skinner's ranch, near the old McAvoy trail from 

Owens Valley over the Inyo Range to Saline Valley, 

Inyo County, Calif. In both Idaho and California it 

is associated with Meekoceras gracilitatis White, M. 

(Koninckites} mushbachanum White, and many other 

species common to the two beds, enough to make certain the approximate correlation of the Meekoceras 

zone in California and Idaho. It was also found by 

R. S. Spence in the Columbites zone, 1 mile west of 

Paris, Bear Lake County, Idaho, associated with 

Columbites parisianus Hyatt and Smith, Ophiceras 

jacksoni Hyatt and Smith, Ophiceras spencei Hyatt 

and Smith, Celtites ursensis Smith, Meekoceras pilatum 

Hyatt and Smith, and other forms. It was also found 

in the Anasibirites subzone of Fort Douglas, Utah, as 

described by A. A. L. Mathews.

Pseudosageceras multilobatum is one of the most 

widely distributed and characteristic of Lower Triassic 

ammonites, occurring in the middle part of the Lower 

Triassic of the Salt Range, the Himalayas, on Timor, 

on Madagascar, in Idaho, California, and Nevada. It 

is essentially characteristic of what is called Flemingites 

beds in the Salt Range, Hedenstroemia beds in the 

Himalayas, and Pseudosageceras multilobatum subzone 

of the Meekoceras zone in Idaho, all of the same age 

and with virtually the same fauna. This is one of the 

most definite interregional zones known in the Triassic 

or in any other part of the geologic column and is of 

great importance in the correlation of faunas in Asia 

and America.

The American form was in press as "Pseudosageceras 

multilobatum" when the writer was informed by a 

letter from Noetling that he was about to publish a 

species under that name. As it was certain that 

Noetling's paper would appear first and extremely improbable that the two species would be more than congeneric, the writer at once changed the name of the 

American form to "P. intermontanum." However, on 

receipt of Noetling's monograph, and after the publication of "The Triassic cephalopod genera of America," 

the writer was by no means certain that the change in 

name was justified. Still later, on receipt of excellent 

material of typical specimens of Pseudosageceras multilobatum from Timor, and on collecting more and better 

specimens of the American form from Idaho, the writer 

was convinced of the identity of the Asiatic and the 

American forms. Hence the older name is restored.

It is by no means certain that all of Noetling's figured specimens really should be kept under Pseudosageceras multilobatum, as the variation is so great. It 

seems possible to the writer that Noetling may even 

have included some specimens of Hedenstroemia. It is 

also quite possible that the two specimens figured by 

the writer on Plate 63, Figures 1-6, may belong to
HAUERITIDAE

another species, as the rest of the fauna in the Columbites zone of Idaho is so different from that "of the 

Meekoceras zone, from which the other specimens came. 

But they were well within the variation limits established by Noetling, and they have been left as named by 

Hyatt and Smith until the discovery of further material 

could settle their true identity.

Noetling published no observations on the ontogeny 

of his species, nor has anyone else, up to the present, 

but it has generally been assigned to what was formerly 

called the Pinacoceratidae. Arthaber 50 has later formulated an elaborate classification of this group, 

assigning Pseudosageceras to his group Beloceratea. 

In this the writer agrees with him, in part, in regarding Pseudosageceras and Sageceras as derivatives of the 

Devonian Beloceras. Young specimens of Pseudosageceras multilobatum, at a diameter of 5.5 millimeters, are 

almost perfect replicas of Beloceras, in the compressed 

high whorl, in the involution, and in the possession of 

well-developed adventitious and auxiliary lobes. They 

bear a close resemblance to the young of Sageceras 

gabbi at about the same size. In the present work the 

young stages of P. multilobatum are shown in Plate 25, 

Figures 10 to 14; the young of Sageceras gabbi are 

shown in Plate 45, Figures 16 and 17.

Diener 51 denies the relationship of Pseudosageceras 

to Beloceras and derives it from the Meekoceratidae. 

However, the writer figures in the present work the 

young of nearly all the genera of Meekoceratidae, 

and none will be found in any way resembling the 

young stages of either Pseudosageceras or Sageceras. 

On the contrary, tliQy all resemble Lecanites and later 

Xenodiscus, the ceratitoid kinship being manifest 

in all.

The peculiar and characteristic beloceran young of 

Pseudosageceras, Sageceras, and Asperities set them 

aside entirely from the typical Prolecanitidae.

A Carboniferous genus, Acrocanites Schindewolf,52 

is here suggested as an intermediary between the 

Devonian Beloceras and the Triassic Pseudosageceras 

and Sageceras. The genus Prodromites Smith and 

Weller,53 though doubtless a descendant of Beloceras, 

is too highly specialized and premature to be this 

intermediary, but for many years it was the only 

possible member of the Beloceratea known from the 

entire Carboniferous. The septum of Acrocanites 

shown in Plate 44, Figure 9, is copied from Schinde-

*° Arthaber, O. von, Die Trias von Albanian: Beitr. Paiaontologie Oesterr.- 

Ungarns u. dos Orients, Band 24, p. 177, 1911.

41 D loner, Carl, XJcbcr Aniinoniten mit Adventivloben: K. Akad. Wiss. Wien 

Dcnkschr., Band 03, p. 173, 1917.

 ' Schiudowolf, 0. H., TJcbcr eine Untcrkarbonfauna aus Ostthiiringcn: Senckcnborgiana, Band 4, Heft 1, 2, p. 15, fig. 2d, 1922.

M Smith, 3. P., Tho Carboniferous nmmonoids of America: U. S. Qeol. Survey 

Mon. 42, p. 34, 1903.

wolf's paper, cited above. The genus has not yet 

been fully studied, so far as the writer knows, and it 

has been wrongly assigned to the stock of Prolecanites. 

It should be looked for in European and American 

collections of Carboniferous fossils, as it furnishes a 

very much needed link in the series. Schindewolf's 

figure shows definite resemblance to the adult of 

Beloceras and strong suggestions of the young of 

Pseudosageceras and Sageceras. In all these forms 

the possession of adventitious and auxiliary lobes at 

at an early stage is positive.

Schmidt 54 cites Acrocanites multilobatus Schindewolf 

as a Beloceras-\iliQ form, too high up in the geologic 

column and with characters too unlike the Prolecanites 

stock to be attached to them. Nothing else has yet 

been published about this very interesting form, which 

may prove to be a veritable "missing link" partly 

recovered.

Superfamily DIMORPHOCERATOIDEA

Family HAUERITIDAE 

Genus LANCEOLITES Hyatt and Smith

1905. Lanceoliles. Hyatt and Smith, The Triassic cephalopod 

genera of America: U. S. Geol. Survey Prof. Paper 40, 

p. 113.

1917. Lanceolites. Diener, Ueber Ammoniten mit Adventivloben: K. Akad. Wiss. Wien Denkschr., Band 93, 

p. 176.

Type: Lanceolites compactus Hyatt and Smith, 

Lower Triassic Meekoceras zone.

Form compact, laterally compressed, sides flattened, 

venter flattened, with sharp shoulder angles. Involute, deeply embracing, closed umbilicus. In youth 

the flat venter has a broad, shallow furrow, but this 

disappears at maturity. The form is thus seen to be 

exactly similar to that of Cordillerites, but the septa 

would distinguish the two genera at once. In Lanceolites the septa are complex, digitate, and lanceolate. 

There is a short adventitious series of simple lobes, 

two laterals, of which the first is deeply digitate and 

the second less so, and a series of tongue-shaped 

auxiliaries. The saddles are divided as well as the 

lobes. The septa suggest some relationship with 

Cordillerites, but that genus, though it has lanceolate 

septa, stih1 has a more complex plan for its lobes. They 

may be parallel developments from kindred stocks.

Lanceolites is known only from the Meekoceras zone 

of the Lower Triassic in the Aspen Ridge of southeast 

Idaho, in eastern Nevada, and from the same horizon 

in the Inyo Range, eastern California, where the 

species described below were found.

M Schmidt, H., Die carbonischen Qoniatiten Deutschlands: Preuss. geol. Landesanstalt Jahrb., Band 45, p. 543, 1925.
90 LOWER TEIASSIC AMMONOIDS OF NORTH AMERICA

Lanceolites compactus Hyatt and Smith

Plate 4, Figures 4-10; Plate 5, Figures 7-9; Plate 21, Figures 

21-23; Plate 28, Figures 17-20; Plate 40, Figures 9-11; 

Plate 60, Figure 10

1905. Lanceolites compactus. Hyatt and Smith, The Triassic 

cephalopod genera of America: U. S. Geol. Survey 

Prof. Paper 40, p. 113, pi. 4, figs. 4-10; pi. 5, figs. 

7-9; pi. 78, figs. 9-11.

1927. Lanceolites compactus. Smith, Upper Triassic marine 

invertebrate faunas of North America: U. S. Geol. 

Survey Prof. Paper 141, p. 72, pi. 21, figs. 21-23.

Form involute, discoidal, laterally compressed. 

Whorl deeply embracing and deeply indented by the 

inner volution. Umbilicus completely closed. Sides of 

whorl flattened, gently convex, abdominal shoulders 

angular, venter narrow, flat, or even slightly depressed 

below the shoulder angles. The height of the last 

whorl is two-thirds of the diameter of the shell, and the 

breadth is half the height. The width of the venter is 

one-third of the greatest thickness of the shell, which 

occurs just above the umbilical shoulders.

The surface is nearly smooth, no ribs or spines being 

visible, but there are faint radial folds visible on the 

cast. The shell is not preserved on any specimen 

found. Length of body chamber unknown.

The septa are complex, with lanceolate digitation of 

the lobes. The external lobe is divided by a narrow 

siphonal .saddle into two broad digitate branches. 

The first lateral lobe is broad and deep, with long 

linguiform digitations. The second lateral lobe is 

narrower and shallow, also digitate. There is an 

auxiliar}?- series of several tonguelike small lobes above 

the umbilicus.

The form of this species is exactly like that of Cordillerites angulatus, but the septa show fundamental 

differences. The septa in the young stages show some 

resemblance to Dimorphoceras. In early youth, 

at the diameters of 4.5 and 5.5 millimeters (as shown on 

pi. 28, figs. 17-20), the shell and septa are remarkably 

like the Devonian and lower Carboniferous genus 

Aphyllites Mojsisovics. In adolescence, at the diameter of 8 millimeters (as shown on pi. 20, figs. 21-23), 

the septa have become more complex, with the lanceolate division of the large lateral lobe beginning. 

This stage corresponds to some unknown Permian 

genus distantly resembling and distantly related to 

°Thalassoceras, not a derivative of Dimorphoceras but 

from some kindred form. The young of Fremontites 

ashleyi Hyatt and Smith,55 of the Upper Triassic of 

California, are almost exactly like this stage of Lanceolites. Fremontites is a typical member of the Haueritidae, and this is very good evidence that this family is 

derived from Lanceolites or from some form very like it.

Horizon and locality: Rare in the Lower Triassic 

Meekoceras zone (Pseudosageceras multilobatum Sllb33 Smith, J. P., Upper Triassic marine invertebrate faunas of North America: 

U. S. Qeol. Survey Prof. Paper 141, p. 74, pi. 63, figs'. 13-15, 1927.

zone) of southeastern Idaho, at locality 1, 5 miles 

southeast of Grays Lake; locality 3, head of Wood 

Canyon, Aspen Mountains, 9 miles east of Soda 

Springs; also in the Owenites subzone of the Meekoceras 

zone at Union Wash, Inyo Mountains, 15 miles southeast of Independence, Inyo County, Calif. In Idaho it 

was associated with Meekoceras gracilitatis, Flemingites 

russelli, Pledenstroemia kossmati, Pseudosageceras multilobatum, Ussuria waageni, and other forms. In 

California it was associated with Meekoceras gracilitatis, Sturia compressa, Inyoites oweni, Owenites 

koeneni, Anasibirites noetlingi, and other forms.

Lanceolites bicarinatus Smith, n. sp.

Plate 55, Figures 1-2

High-whorled, involute, deeply embracing, laterally 

compressed. Umbilicus closed, venter narrow, with 

shallow ventral furrow, and distinct marginal keels.

Septa linguiform, but with both lobes and saddles 

slightly digitate. There is a short adventitious series 

consisting of small tongue-shaped lobes, a large principal lateral deeply divided by secondary lobes, with a 

smaller second lateral, and a short auxiliary series.

Lanceolites bicarinatus is rather closely related to 

L. compactus but differs in the greater compression 

of the whorl and the more complex septa. Both 

species have a considerable resemblance to the Upper 

Triassic Fremontites, and either one might be the 

ancestor of the Haueritidae.

Horizon and locality: Rare in the Lower Triassic 

Owenites subzone of the Meekoceras zone of Union 

Wash, IK miles east of Union Spring, Inyo Mountains, 

15 miles southeast of Independence, Inyo County, 

Calif., and at the same horizon at the Phelan ranch, 

Elko County, 70 miles south of Wells, and on the east 

side of the Ruby Range, Nev.; associated with Meekoceras gracilitatis, Inyoites oweni, Owenites koeneni, 

Anasibirites desertorum, Pseudosageceras multilobatum, 

Aspenites acutus, Juveniles dieneri, and other forms.

Family THALASSOCERATIDAE

Form involute, with laterally compressed, higharched whorls and narrow, rounded venter. Surface 

smooth, or ornamented with spiral striae. Septa 

ammonitic, but in the more primitive forms the saddles 

are entire, although the digitations run high up on the 

sides of the saddles.

In this family are included Thalassoceras Gemmellaro, 

Ussuria Diener, and Sturia Mojsisovics. The two 

former genera are commonly accepted as standing in 

genetic connection and as having been derived from 

the Carboniferous genus Dimorphoceras. Sturia has 

hitherto been assigned to the Ptychitidae, but a species 

has been found in the Lower Triassic of California 

that seems to connect Ussuria with it, and this necessitates classing both with the Thalassoceratidae, with
THALASSOCERATIDAE 91

which they are clearly more closely allied than with 

the Ptychitidae.

Tlialassoceras is known from the Permian of the 

Mediterranean region, Texas and Timor; Ussuria 

only from the Lower Triassic of Siberia, India, and 

Idaho; and Sturia only from the Lower Triassic of 

California and from the Middle and Upper Triassic 

of the Alpine province and the Middle Triassic of the 

Himalayas.

Genus USSURIA Diener

1895. Ussuria. Diener, Triadische Cephalopodenfaunen der

ostsibirischen Kiistenprovinz: Com. gc"ol. [St.-P6tersbourg] M<5m., vol. 14, No. 3, p. 23. 

1902. Ussuria. Frech, Lethaea geognostica, Teil 1, Das

Palaeozoicum, Band 2, Lief. 4, p. 659. 

1905. Ussitria. H'yatt and Smith, The Triassic cephalopod

genera of America: U. S. Geol. Survey Prof. Paper

40, p. 88. 

19.17. Ussuria. Diener, Ueber Ammoniten mit Advent!vloben:

K. Akad. Wiss. Wien Denkschr., Band 93, p. 166. 

1922. Ussuria. Welter, Die Ammoniten der Unteren Trias

von Timor: Palaeontologie von Timor, Lief. 11, Abh.

19, p. 100.

Type: Ussuria iwanowi Diener. 56

Compressed, involute, deeply embracing, whorls increasing rapidly in height. Umbilical shoulders 

broadly rounded, sides gently convex up to the narrow 

and rounded, venter. Umbilicus narrow and deep. 

Surface without ribs or constrictions but provided 

with, fine spiral striae (seen on specimens from California).

Septa, both lobes and saddles ammonitic,digitate, 

and highly specialized. The external lobe is divided 

by a broad digitate siphonal saddle, and each side of 

the lobe is deeply trifid, with secondary indentations 

on the prongs. There are two or three principal 

lateral lobes, wide, deep, and deeply digitate; the 

auxiliaries, of which there are three or more, are smaller 

but also digitate. The internal lobes have not been 

observed in detail, but broken whorls show that there 

is a long, narrow antisiphonal lobe, flanked by a pair 

of laterals on each side.

Diener considers this genus as a descendant of 

Tlialassoceras Gemmellaro, 57 which has somewhat simpler, though ammoni tic septa, in which there are two 

digitate lateral lobes and a single simple auxiliary. 

Tlialassoceras lias a depressed subglobose form, with 

the whorls usually broader than high, whereas the 

adults of Ussuria are high-whorled and compressed. 

But the young of the latter genus are robust and subglobose, resembling Tlialassoceras both in form and 

septa, and the still younger stages are like Dimorphoceras. These observations have been made only 

on an Ussuria waageni H'yatt and Smith from the

!0 Dicncr, Curl, Triadische Ccphalopodcufauncn der ostsibirischen Kiistenprovinz: 

Com. (,'col. [St.-Petorsbourg] Mem.,' vol. 14, No. 3, p. 27, pi. 3, fig. 5, 1895.

57 Ocinincllaro, 0. 0., La fauna doi calcari con Fusulina dclla valle del Fiuine: 

Sosio nclla provincin di Palermo, p. 69, 1887.

67664 32 7

Meekoceras zone of Idaho, no young stages of Sturia 

compressa Hyatt and Smith having been seen. Thalassoceras is supposed to have been derived from Dimorphoceras, based on the resemblance of the adults and 

on Gemmellaro's observations on its ontogeny.

Ussuria bears a certain resemblance to Sturia 

Mojsisovics, commonly assigned to the Ptychitidae, 

in its compressed form, spiral striae, and complex 

septa, and a relationship between the two genera is by 

no means unlikely, in spite of the difference in complexity of the septa.

Hyatt classed Ussuria in a new family, the Ussuritidae, under the suborder Phylloceratida, but this was 

before any observations had been made on the ontogeny of the genus or any species of it was known 

except the Siberian forms.

Ussuria is known at present in the Lower Triassic 

Proptychites beds of Ussuri Bay in eastern Siberia, in 

the Meekoceras zone of the Aspen Ridge in southeast 

Idaho, and in beds at the same horizon on Timor, in 

all three places associated with Meekoceras, Pseudosageceras, Ophiceras, and Xenodiscus, with closely 

allied species.

Ussuria occidentalis Smith, n. sp.

Plate 27, Figures 8-12

Form involute, high-whorled, laterally compressed. 

Sides flattened, venter rather narrowly rounded. 

Umbilicus nearly closed. Septa ammonitic, with 

digitate lobes, and cremilate saddles. There are a 

principal external lobe, rather long and narrow, a short 

adventitious lobe, a large external lobe, and several 

auxiliaries, decreasing in size and complexity toward 

the umbilicus.

Dimensions of type specimen of Ussuria occidentalis

Height of last whorl. . __.._. _ . _

Height of last whorl from the preceding.-.-....

Width of last whorl. _. ... .. __ ____________

Millimeters

84

55

33

21

22

3

Ratio

100

65

40

25

26

3

Ussuria occidentalis is very closely related to U. 

waageni Hyatt and Smith, with which it is associated. 

It differs from that species in its greater lateral compression, higher whorl and more rapid increase in 

height, narrower umbilicus, and slightly simpler 

septa. The saddles are somewhat more club-shaped, 

with broader tops and greater constriction at the base ; 

the external lobe is also not so narrow as that on U. 

waageni.

These two species differ from the Asiatic typical 

forms in the possession of a well-marked adventitious 

lobe.
92 LOWER TRIASSIC AMMONOIDS OF NORTH AMERICA

Horizon and locality: Ussuria occidentalis is rare in 

the Lower Triassic Pseudosageceras multilobatum subzone of the Meekoceras zone (equivalent of the Hedenstroemia or Flemingites zone of India), at locality 3, 

head of Wood Canyon, Aspen Mountains, 9 miles 

east of Soda Springs, southeastern Idaho. It was 

associated with Meekoceras gracilitatis, M. mushbachanum, Flemingites russelli, Pledenstroemia kossmati, Paranannites aspenensis, Pseudosageceras multilobatum, Lanceolites compactus, Cordillerites angulatus, 

and many other species characteristic of this horizon.

Ussuria waageni Hyatt and Smith

Plate 21, Figures 24-40; Plate 42, Figures 1-8; Plate 60, Figures 15-20; Plate 65, Figures 1-5; Plate 66, Figures 1-12; 

Plate 67, Figures 1, 2

1905. Ussuria waageni. Hyatt and Smith, The Triassic 

cephalopod genera of America: U. S. Geol. Survey 

Prof. Paper 40, p. 90, pi. 65, figs. 1-5; pi. 66, figs. 1-12; 

pi. 67, figs. 1, 2; pi. 85, figs. 1-8.

1927. Ussuria waageni. Smith, Upper Triassic marine invertebrate faunas of North America: U. S. Geol. Survey 

Prof. Paper 141, pi. 21, figs. 24-40.

Discoidal, involute, laterally compressed. Whorls 

high and increasing rapidly in height, deeply embracing, and deeply indented by the inner whorls. Sides 

flattened, with narrow rounded venter and no marked 

umbilical shoulders. The umbilicus is very narrow, 

being somewhat less than one-tenth of the entire 

diameter of the shell. The height of the last whorl 

is more than half the diameter of the shell, the width 

slightly more than half the height of the whorl, and 

it is indented to nearly one-seventh of its height by 

the inner whorl.

Proportions of shell of Ussuria waageni at maturity

Diameter.________ ______________________ 100

Height of last whorl.._-_______-______-_-_ 56

Height of last whorl from the preceding.__ 43 

Width of last whorl____ ________________ 29

Involution-_____-_--_-_-___.______ ._____ 13

Width of umbilicus.-..------------------- 8

The greatest width of the whorl lies at a point about 

halfway up the flanks, some distance above the contact with the inner volution. The surface is nearly 

smooth, showing neither ribs nor constrictions but faint 

radial folds and striae of growth.

The septa are very complex, consisting of a rather 

small external lobe divided by a siphonal saddle, a 

small first lateral lobe, larger second lateral, and 

smaller third lateral, besides a long series of auxiliaries, 

decreasing in size and complexity toward the umbilicus. 

The external and the lateral lobes are deeply digitate, 

whereas the auxiliaries are much simpler in form. 

The saddles are all narrower than the lobes and 

somewhat phylloid.

These septa are more complex than those of Ussuria 

schamarae Diener and U. iwanowi Diener, from Siberia,

but show that this species is congeneric with them. 

It must also be taken into account that the Idaho 

species is very large and that the Siberian species may 

have reached the same complexity of septation if such 

large specimens of them had been found.

The foregoing description applies only to the mature 

shell, for the young stages differ very much from the 

adult. An unusually good series of young stages was 

obtained, and as they show clearly the phylogeny of 

the genus they have been fully illustrated. The mature 

shell was found up to a diameter of 150 millimeters 

fully septate, and the complete shell must have been 

nearly 300 millimeters in diameter.

The smallest stage obtained has a diameter of 5.5 

millimeters, is evolute, little embracing, with low, 

broadly rounded whorls, with simple goniatitic septa. 

The form and septa correspond to the Carboniferous 

genus Dimorphoceras. The change from glyphioceran 

septa to those characteristic of Dimorphoceras may 

be observed on the outer volution of this specimen, 

which is figured on Plate 42, Figures 5-8. For comparison with this the septa of Dimorphoceras gilbertsoni 

Phillips and D. atratum Goldfuss, of the Carboniferous, 

are figured on Plate 42, Figures 11 and 12.

At the diameter of 11 millimeters the shell shows a 

transition from Dimorphoceras to Thalassoceras. In 

the beginning of the digitation of the lobes the whorl 

becomes higher at this stage but not yet flattened as 

at maturity. This stage is figured on Plate 42, Figures 

1-4. For comparison with.it, the septa of Thalassoceras 

gemmellaroi Karpinsky and T. phillipsi Gemmellaro 

are figured on Plate 42, Figures 9 and 10.

At the diameter of 13 millimeters the form and 

septa are more like the highly specialized species of 

Thalassoceras known from the Permian; this stage is 

figured in Plate 66, Figures 10-12.

At the diameter of 17 millimeters the shell and septa 

show a transition from Thalassoceras to Ussuria in the 

flattening of the sides, increased height of whorl, 

greater complexity of lobes, and pronounced development of the auxiliary lobes. This stage is shown in 

Plate 66, Figures 7-9.

At the diameter of 30 millimeters the stage of 

development of the septa agrees with that of Ussuria 

schamarae Diener and U. iwanowi Diener, from the 

Lower Triassic of Siberia. It is possible, however, that 

the species described by Diener may have been based 

on young individuals. This stage of Ussuria waageni 

is figured in Plate 66, Figures 4-6.

At the diameter of 35 millimeters the shell and septa 

already show the most significant characters of maturity but are not yet so complex as in the larger specimens. This is shown in Plate 66, Figures 1-3.

The fully mature shell is figured in Plate 65, Figures 

1-5, and Plate 67, Figures 1 and 2. The septa of 

Ussuria iwanowi Diener, from the Lower Triassic of
THALASSOCERATIDAE 93

Siberia, are figured for comparison in Plate 66, Figure 

25.

The development of Ussuria waageni is remarkable, 

in that we can trace the species in its ontpgeny through 

stages corresponding successively to some gephyroceran 

form of the Devonian; then through the stage corresponding to the simpler species of Dimorphoceras in the 

Mississippian; then to the more complex species of 

Neodimorphocems of the "Coal Measures"; then to the 

simpler species of Thalassoceras of the lower Permian 

or Artinsk stage; then to the more complex Tlialassoceras of the upper Permian; and lastly through 

gradually increasing complexity into Ussuria. The 

stages come in the exact order of the geologic sequence 

of mature genera, so that the agreement of phytogeny 

and ontogeny is perfect.

Of course this is what we should expect in Lower 

Triassic species, for the time of the Meekoceras fauna 

is not greatly removed, from that of the Permian faunas 

of Sicily and the Artinsk stage, nor yet very remote 

from even the Carboniferous. But such close correlation of individual development and geologic history is 

rare, even in Lower Triassic species, and especially in 

such complex forms, where the adult differs so markedly from the young.

Ussuria waageni Hyatt and Smith differs from 

U. iwanowi Diener and U. schamarae Diener in the 

greater complexity of its septa but agrees with them 

in the general plan of lobes and saddles. It agrees 

in general with Sturia compressa Hyatt and Smith, 

from the Lower Triassic Meekoceras zone of California, 

but differs from that species in the more robust whorl in 

all stages observed. The saddles in both the American 

species are more digitate than in the Asiatic forms, 

and the subdivision of the lobes is more complex. It 

has been, suggested by Frech 58 that the Siberian species 

of Ussuria did. not occur in the Lower Triassic, as 

Diener supposed, but in the Permian. It is certain, 

however, that the Siberian as well as the American 

species of this genus belong to the Lower Triassic, and 

that their greater simplicity of development is due to 

their occu.rre.nce at a lower horizon of the Triassic.

Horizon and locality: Ussuria waageni is rather 

common in the Meekoceras zone of the Lower Triassic, 

at the head of Wood. Canyon, 9 miles east of Soda 

Springs, Aspen Ridge, southeastern Idaho. It was 

associated with Meekoceras gracilitatis White, M. 

mushbachanum White, Pseudosageceras multilobatum 

Noetling, Flemingites russelli Hyatt and Smith, 

Hedenstroemia kossmati Hyatt and Smith, Ophiceras 

dieneri Hyatt and Smith, Paranannites aspenensis 

Hyatt and Smith, Cordillerites angulatus Hyatt and 

Smith, A.spidites, and many other forms characteristic 

of this horizon.

33 Frocli, Fritz, Dio Dyas: Lothnca gcognostica, Teil ], Das Palaeozoicum, 

Hand 2, Liof. 4, p. 059, 11)02.

Genus STURIA Mojsisovics

1882. Sturia. Mojsisovics, Die Cephalopoden der Mediterranen Triasprovinz: K.-k. geol. Reichsanstalt Wien 

Abh., Band 10, p. 240.

1892. Sturia. Hauer, Beitriige zur Kenntniss der Cephalopoden aus der Trias von Bosnian: K. Akad. Wiss. Wien 

Denkschr., Band 59, p. 283.

1895. Sturia. Diener, Cephalopoda of the Muschelkalk: 

India Geol. Survey Mem., Palaeontologia Indica, 

15th ser., Himalayan fossils, vol. 2, pt. 2, p. 113.

1902. Sturia. Mojsisovics, Die Cephalopoden der Hallstatter 

Kalke: K.-k. geol. Reichsanstalt Wien Abh., Band 6, 

Supplement-Heft, p. 309.

1910. Sturia. Renz, Triadische Faunen der Argolis: Palaeontographica, Band 58, p. 24.

1914. Sturia. Welter, Die Obertriadischen Ammoniten und 

Nautiloiden von Timor: Palaeontologie von Timor, 

Lief. 1, p. 198.

Robust, involute, laterally compressed, deeply embracing, narrowly umbilicate, high whorled. Surface 

without ribs or constrictions but with sharp spiral 

lines. Septa ammonitic, deeply digitate, with ground 

plan of lobes and saddles pyramid shaped. There 

are a divided ventral lobe, a large first lateral, a smaller 

second lateral, and a series of several auxiliaries, 

decreasing regularly in size toward the umbilicus. 

Inner septa unknown. Length of body chamber less 

than a revolution.

Sturia is supposed to be related to the Thalassoceratidae, but its real kinship is unknown, for its 

development has not been worked out. The septal 

plan is somewhat like that of Procarnites Arthaber, 

but intimate relationship with that genus is improbable. 

The external form and spiral lines have some resemblance to Cladiscites Mojsisovics, but the plans of the 

septa of the two genera have no resemblance.

Sturia is essentially characteristic of the Middle 

Triassic but occurs also in the Upper Triassic, and two 

species have been found in the Owenites subzone of 

the Lower Triassic Meekoceras zone of California, 

Sturia compressa Hyatt and Smith, and S. woodini 

Smith.

Sturia compressa Hyatt and Smith

Plate 3, Figures 6-11

1905. Ussuria compressa. Hyatt and Smith, The Triassic 

cephalopod genera of America: U. S. Geol. Survey 

Prof. Paper 40, p. 89, pi. 3, figs. 6-11.

Form compressed, involute, discoidal; whorls deeply 

embracing and increasing rapidly in height, the outer 

whorl being indented to one-fourth of its height by 

the inner. Umbilicus closed, umbilical shoulders 

broadly rounded. Sides gently convex, with greatest 

breadth opposite the top of the inner volution. Venter 

rounded but very narrow. The whole form is thus 

seen to be lenticular, with the greatest thickness of the 

lens exactly in the middle, and one-third of the 

diameter.

The surface of the cast is perfectly smooth, devoid 

of ribs, constrictions, or other ornamentation; but in a
94 LOWER TRIASS1C AMMONOIDS OF NORTH AMERICA

few places the outer shell was preserved, adhering to 

the cast, and on this were observed fine spiral lines 

like those on the shell of other species of Sturia.

The septa are very complex, both lobes and saddles 

being thoroughly ammonitic, much more complex 

than those of Ussuria schamarae Diener and U. 

iwanowi- Diener. The ventral lobe is divided by a 

broad, siphonal saddle, which in turn is broken up by 

several small, short digitations, almost becoming 

adventitious lobes; the two lateral lobes are deeply 

"digitate, the first being much more complex than the 

second. The auxiliary series consists of four or five 

small lobes, scarcely individualized, and inclined 

backward to the umbilical margin. The internal 

septa could not be observed in detail, but broken 

whorls showed a large antisiphonal lobe, flanked by a 

pair of principal internal laterals on each side.

Sturia compressa has more compressed whorls than 

either of the Siberian species and also greater complexity of the septa and can not belong to the same 

genus with them.

Dimensions of the type specimen of Sturia compressa

Millimeters

Diameter _______________________________ 66

Height of last whorl.______________________ 45

Height of last whorl from the preceding- _____ 35

Width of last whorl. _____________________ 20

Involution.________---____---___--_-__- _ 10

Width of umbilicus_---_______--____---__- 0

This specimen was chambered throughout, and the 

species probably grew to twice this diameter.

Horizon and locality: In the Lower Triassic Owenites subzone of the Meekoceras zone of Union Wash, 

near Union Spring, about 15 miles southeast of Independence, Inyo County, Calif., collected by J. P.

Smith.

Sturia woodini Smith, n. sp.

Plate 51, Figures 5, 6

Form, robust, involute, laterally compressed, narrowly iimbilicate. Venter gently rounded. Umbilicus 

shallow and entirely without umbilical shoulders, so 

that the slope of each succeeding whorl coincides with 

that of the preceding one, giving a uniform slope to the 

center of the umbilicus. Surface ornamented with 

fine strong spiral lines.

The outer whorl embraces four-fifths of the inner 

and is indented to one-third of its height. The height 

of the last whorl is half the total diameter of the shell, 

and the width is two-fifths of the height. The width 

of the umbilicus is one-eighth of the diameter of the 

shell.

Sturia woodini is related to S. compressa Hyatt and 

Smith, with which it is associated, but differs in its 

more robust and less compressed whorl, broader venter, and stronger spiral lines.

Septa unknown, but the similarity to Sturia compressa makes the generic reference rather certain.

Named in memory of Doctor Woodin, in recognition 

of his hospitality and assistance.

Horizon and locality: Very rare in the Lower 

Triassic Owenites subzone of the Meekoceras zone of 

Union Wash, 1% miles east of Union Spring, 15 miles 

southeast of Independence, Inyo County, Calif.; 

associated with Owenites koeneni, Inyoites oweni, 

Lanceolites compactus, Meekoceras gracilitatis, Aspenites acutus, Anasibirites noetlingi, and many other 

species characteristic of the higher part of the Meekoceras zone.

PRONORITOIDEA

Family PRONORITIDAE

Under this head the writer groups all forms closely 

allied with Pronorites; these are characterized by compressed whorls, little sculpture of the shell, rather short 

body chambers, and lanceolate septa, with pronounced 

development of the auxiliary and little development of 

the adventitious series of lobes. Karpinsky 59 has 

given almost a monograph of this family and has traced 

the ontogeny of several Paleozoic genera, so that a 

comparison of later forms is easy, and the relations 

between phylogeny and ontogeny are clear. This is 

one of the few families in which we can trace with certainty a series of forms, leading up from those with 

simple goniatitic lobes to those with complex ammonitic septa and in which in the ontogeny of each genus we 

can find its family history repeated in abridged form.

This family includes Pronorites Mojsisovics, Uddenites Boese, Sicanites Gemmellaro, Propinacoceras Gemmellaro, Medlicottia Waagen, -Sundaites Haniel, of the 

Paleozoic, and Cordillerites Hyatt and Smith and 

Albanites Arthaber of the Lower Triassic; Medlicottia 

(Episageceras) also occurs in the Lower Triassic of 

India and Timor. Karpinsky has shown that Pronorites in its development can be traced back to Prolecanites; that Sicanites, Propinacoceras, and Medlicottia all show in their ontogeny their origin in Pronorites. In this paper the writer describes the ontogeny 

of Cordillerites, which genus goes through stages corresponding in succession to Proiecanites, Pronorites, and 

Cordillerites. The American representative of the 

Triassic Pronoritidae is so primitive in its stage of 

evolution that it appears to be rather a little-modified 

survivor of Permian type than a characteristic Lower 

Triassic ammonite.

Diener 60 has described, from the Middle Triassic of 

the Alps, a genus Arthaberites, which apparently is 

closely allied with Cordillerites, on account of its tri59 Karpinsky, A., Ueber die Ammoneen der Artinsk-Stufe: Acad. imp. sci. St., 

Petersbourg Mem., 7th ser., vol. 37, No. 2, 1889.

6° Diener, Carl, Die Triadische Cephalopodcn-Fauna der Schiechliughohe bei 

Hallstatt: Beitr. Palaontologie Oesterr.-Ungarns u. des Orients, Band 13, p. 17, pi. 2, 

fig. 4 a-c, 1901
PRONORITIDAE 95

partite external lobe and the lanceolate characters of 

its lobes and saddles. It differs from the rest of the 

Triassic members of the Pronoritidae in the minor 

development of the adventitious series. This is the 

only genus above the Lower Triassic that is thought 

to represent the stock of Pronorites.

Genus CORDILLERITES Hyatt and Smith

1905. Cordilleriles. Hyatt and Smith, The Triassic cephalopod

genera of America: U. S. Geol. Survey Prof. Paper

40, p. 109. 

1917. Cordillerites. Diener, Ueber Ammoniten mit Adventivloben: K. Akad. Wiss. Wien Denkschr., Band 93, p. 175. 

1929. Cordillerites. Mathews, The Lower Triassic cephalopod

fauna of the Fort Douglas area, Utah: Walker Mus.

Mem., vol. 1, No. 1, p. 3.

Type: Cordillerites angulatus Hyatt and Smith, 

Lower Triassic.

This genus is compressed, involute, deeply embracing, 

robust, with flattened sides, flat angular venter, and 

narrow umbilicus. The only surface sculpture visible 

on the casts consists of faint radial folds and striae of 

growth. The septa are lanceolate, with rounded 

saddles, and lobes partly serrated. The external or 

siphonal lobe is tripartite, as in Pronorites. There is 

a short series of lanceolate simple or bifid adventitious 

lobes, a series of laterals that are partly bifid and partly 

trifid, and a long series of auxiliaries, of which those 

nearest the umbilicus are undivided. The general 

plan of the septa is very like that of Pseudosageceras, 

but the lobes are not nearly so complex nor so numerous. 

There is a closer resemblance to Arthaberites Diener,61 

but the lobes of Artliaberites are uniformly trifid, and 

are of simpler plan than those of Cordillerites.

An equally close resemblance exists with Prodromites 

Smith and Weller, of the Mississippian ("Lower Carboniferous ")> but Cordillerites has a flattened venter 

and no keel, and the general plan of the septa, though 

superficially similar, in noteworthy details is quite 

dissimilar.

The ontogeny of the only known species of Cordillerites shows clearly the origin of the genus. The 

earliest observed stage resembles Prolecanites, having 

a somewhat compressed moderately involute form, 

with an undivided ventral lobe . and two or more 

lanceolate lateral lobes. After this follows a stage in 

which the ventral lobe becomes tripartite, corresponding to Paraprolecanites. The outline of the whorl then 

becomes subqiiadraugular, and the first lateral lobe 

becomes bifid, corresponding to Pronorites. Shortly 

after this, the first lateral lobe becomes tripartite, still 

corresponding to Pronorites, as some species of that 

genus have this character. Then the second lateral 

lobe becomes bifid, and the form is transitional from 

Pronorites toward Cordillerites. Next, the first lateral

oi Dioncr, Cnrl, op. cit. (Die Triadischo Cephalopodcn-Fauna dcr Scbiechlinghohe 

boi Uallstatt), p. 17, pi. 2, figs. 4 a-c.

saddle becomes indented, the beginning of the adventitious series, which develops with great rapidity, 

though not reaching the number of the auxiliaries, 

which began earlier; that is, with the Pronorites stage.

The large tripartite lateral lobe of Cordillerites corresponds to the bifid or tripartite lateral of Pronorites; 

the adventitious lobes are made by subdivision of the 

first lateral saddle and at maturity may number as 

many as three. The second lateral lobe at maturity is 

tripartite and just before maturity is bifid. The third 

lateral lobe becomes bifid at maturity and before 

maturity is undivided. The auxiliaries decrease in 

size and complexity toward the umbilicus, as they do in 

all genera of the Pronoritidae.

This development shows the intimate Idnship of 

Cordillerites with Medlicottia, from which it differs only 

in the form of the external lobe, the exaggerated development of the lanceolate adventitious lobes, :and the 

tripartite laterals. Medlicottia in its ontogeny goes 

through stages corresponding successively to Prolecanites, Paraprolecanites, and Pronorites, somewhat 

as does Cordillerites but diverges in the peculiar development of the siphonal lobe and the external saddle.

Cordillerites is known only from the Lower Triassic 

.Meekoceras zone of the Aspen Ridge, in southeast 

Idaho, where it is represented by a single species.

Diener 62 declines to accept Cordillerites as a member 

of the Pronoritidae but would place it either with 

Pledenstroemia or with Pseudosageceras. If it belongs 

with Hedenstroemia, it is a member of the Meekoceratidae and should show young like Xenodiscus. If it 

belongs to Pseudosageceras it should show young like 

Beloceras. But it does neither. Its young are compact, involute, subquadratic, with a very early appearance of division and complication of the.lobes, utterly 

unlike any Xenodiscidae, though not quite like any 

known species of Pronorites. The resemblance is somewhat greater to Pseudosageceras, but that genus in its 

youth shows the long series of multiplicate serial lobes, 

with early development of both adventitious and 

auxiliary lobes, utterly foreign alike to the Pronoritidae 

and to descendants of the Xenodiscidae.

The genus Uddenites, described by Bose,63 after the 

observations of Diener and the writer, shows a descendant of Pronorites, tending toward Medlicottia. 

Arthaber's genus Albanites,64 which he later withdrew 

and renamed "Pronorites," is another example of the 

same sort of thing. There are probably many as yet 

unknown genera of the Pronorites stock which will 

help us to fill out the gaps suggested by ontogenetic 

studies. In the meantime we need not feel com02 Diener, Carl, Ueber Ammoniten mit Adventivloben: K. Akad. Wiss. Wien 

Denkschr., Band 93, p. 175, 1917.

83 Bose, Emil, The Permo-Carboniferous ammonoids of the Glass Mountains, 

west Texas: Texas Univ. Bull. 1762, p. 55, 1917.

' Arthaber, G. von, Ueber neue Funde in der Trias von Albanien: Geol. Gesell. 

Wien Mitt., Band 2, p. 232, 1909; Die Trias von Albanien: Beitr. Palaontologie 

Oesterr.-Ungarns u. des Orients, Band 24, p. 204, 1911.
96 LOWER TEIASSIC AMMONOIDS OF NORTH AMERICA

pelled to throw all these somewhat doubtful forms 

into the too generous and receptive Meekoceratidae.

Cordillerites angulatus Hyatt and Smith

Plate 2, Figures 1-8; Plate 42, Figures 14-20; Plate 60, 

Figure 14; Plate 68, Figures 1-10; Plate 71, Figures 1-6

1905. Cordilleriles angulatus. Hyatt and Smith, The Triassic 

cephalopod genera of America: U. S. Geol. Survey 

Prof. Paper 40, p. 110, pi. 2, figs. 1-8; pi. 68, figs. 1-10; 

pi. 71, figs. 1-6; pi. 85, figs. 14-20.

Form compressed, involute, discoidal, deeply embracing, the outer whorl being indented to one-third 

of its height by the preceding whorl. Umbilicus 

closed. Sides with rather abrupt umbilical shoulders, 

and gentle convex curve up to the abdominal shoulder 

angles. Venter flat and rather broad, with abdominal 

furrow in youth, which disappears in age. Surface 

ornamentation consisting of obscure radial folds and 

striae of growth. The length of the body chamber 

is unknown.

Septa lanceolate, with rounded saddles, and tongueshaped lobes, mostly either bifid or trifid. The 

ventral lobe is rather short and tripartite. Near the 

abdominal shoulders is a series of three adventitious 

lobes, increasing in size away from the venter; the 

first of these is undivided, the second and third bifid. 

The third adventitious lobe is very large, deeply 

bifid, and occurs well down on the flanks; from its 

size and position it might well be called a lateral lobe 

if it were not a secondary development out of the 

external saddle. Its nature as an adventitious lobe 

would not even be suspected if one could not trace 

its gradual growth from a mere notch in the external 

saddle.

The true lateral lobes number two; the first is 

regularly and deeply tripartite, and longer and 

broader than the third adventitious lobe; the second 

is irregularly tripartite, with the prong nearest the 

venter longer than the other two, which are separated 

only by a shallow notch.

After this follows a long series of auxiliary lobes, 

growing smaller toward the umbilicus; the first three 

are distinctly bifid, the two others are apparently 

simple. The details of the internal septa could not 

be seen, but there is a long antisiphonal lobe, flanked 

by at least five internal laterals.

In its ontogeny Cordillerites angulatus shows its 

history and derivation from Pronorites. In the 

youngest stage seen, at a diameter of 2.5 millimeters, 

the whorl is moderately involute, rounded and somewhat compressed laterally. The septa consist of an 

undivided ventral lobe and two laterals. This stage 

corresponds to Prolecanites of the Devonian and Carboniferous.

At a quarter of a revolution farther on, at a diameter 

of 3.5 millimeters, the ventral lobe begins to divide

and becomes indistinctly tripartite, and at the same 

time a third lobe is added outside of the umbilicus.

At a diameter of 4 millimeters, two septa farther 

on and about one-eighth of a revolution more, the 

first lateral lobe begins to divide. This is the beginning of the Pronorites stage, and the likeness is made 

greater by the accompanying development of the 

auxiliary series.

A quarter of a revolution farther on, at a diameter 

of 5.5 millimeters', the second lateral lobe becomes 

bifid, and the first is distinctly tripartite. Pronorites 

never had this character, but a descendant of that 

genus, Sicanites, of the Permian, did have it. This 

stage may therefore be said to be transitional from 

Pronorites to a genus somewhat like Sicanites. It lacks, 

however, a character that was distinctive of Sicanites, 

the division or notching of the external saddle.

At the diameter of about 7 millimeters the notching 

of the external saddle and the development of the 

adventitious series of lobes begin. Even then this 

stage can not be said to correspond with Sicanites, for 

the parallelism is obscured by the earlier inheritance 

in the larva of the tripartite principal lateral lobe, a 

character that Sicanites never acquired. This merely 

means that we have occurring simultaneously in this 

stage of growth some characters that were characteristic of Sicanites, along with others that were characteristic of kinsmen of that genus.

The Sicanites-like stage of growth is very short, just 

as was the life of that genus in the geologic succession, 

and very soon it is obscured by the appearance of 

characters that belonged to the mature stage. This 

follows naturally from the unequal acceleration of 

characters in inheritance.

When the adolescent stage is well advanced there 

is a single adventitious lobe, but this is soon followed 

by the appearance of a second smaller lobe nearer the 

venter, by further division of the external saddle. 

The first adventitious lobe by this time has become 

bifid, and the second soon becomes so.

At a diameter of 10 millimeters the septa resemble 

Sicanites, and at 12 millimeters they resemble those 

of the more primitive species of Propinacoceras, in the 

development of two distinct adventitious lobes.

At the diameter of 17 millimeters the first adventitious lobe is divided, the second still simple, and the 

third is just beginning to form. No change has taken 

place in the first lateral lobe, but the second has become 

tripartite instead of bifid, and the first auxiliary has 

become bifid. The other auxiliaries remain simple, 

as they do through life. At this stage there is a simultaneous occurrenceof characters that belonged to 

Propinacoceras and Cordillerites.

The only advance to be made now is the development 

of the third adventitious lobe by a further division of 

the external saddle. This takes place at the diameter
PRONOB1TIDAE 97

of 30 millimeters, and the species has attained its full 

generic characters, although not yet mature size

It is easy to trace this development because the 

first lateral lobe is constant from the Pronorites stage 

until maturity, and the new elements' are added and 

changes introduced into the lobe on both sides of it. 

The adventitious lobes are of simple character, and 

progress but little beyond the development attained 

in Sicanites and Propinacoceras. The same thing is 

true of the auxiliary series. The advance over those 

two genera is made chiefly in the prominence and special development of the two lateral lobes.

Pronorites, of the Carboniferous, progressed up to 

the stage shown on Plate 71, Figures 7 and 8, and 

stopped. Sicanites, of the lower Permian, went through 

the Pronorites stage and began the formation of the 

adventitious series by indentation of the external 

saddle. Propinacoceras, of the Permian, went through 

all the stages of Pronorites and Uddenites and advanced 

beyond them in the formation of two distinct adventitious lobes in the same way. Cordillerites in the Lower 

Triassic went through the stages corresponding to 

Pronorites and later to unknown genera resembling 

somew.li.at Propinacoceras, and it went beyond them 

in the further development of the adventitious series 

and in the greater complexity of the first and second 

lateral lobes.

The septa of these forms, showing their gradual 

advance, are figured in PI ate 71. In the development of 

Cordillerites we see a species going through in its ontogeny all the stages gone through by its Paleozoic ancestors and in the same succession as did the genetic 

series of mature forms.

Horizon and locality: Cordillerites angulatus is not 

uncommon in the Lower Triassic Meekoceras zone of 

Wood Canyon, 9 miles east of Soda Springs, Aspen 

'.Ridge, southeastern Idaho. It was accompanied by 

Meekoceras gracilitatis, M. mushbachanum, Flemingites 

russelli, Hedenstroemia kossmati, Lanceolites compactus, 

Pseudosageceras multilobatum, Aspenites acutus, Paranannites aspenensis, and other species.

Cordillerites compressus Mathews 

Plate 79, Figures 3, 4

1929. Cordillerites compressus. Mathews, The Lower Triassic 

cephalopod fauna of the Fort Douglas area, Utah: 

Walker Mus. Mem., vol. 1, No. 1, p. 3, pi. 1, figs. 15-17.

The following description is taken from Mathews's 

paper:

Form extremely involute, discoidal, highly compressed 

laterally; whorls increasing rapidly in height, completely embracing, and greatly indented by the penultimate volution. 

Sides nearly flat and sloping from the greatest width of the shell 

which is at the umbilical shoulder to the ventral shoulder forming a sharp wedge in cross section. Umbilicus is closed. 

Umbilical shoulder is almost indistinguishable. Inner wall 

sloping at an angle of about 8° with the side of the preceding 

whorl. The height of the last whorl is over three times its

greatest thickness and five-eighths its diameter. It is indented 

to over two-fifths its height by the penultimate volution and 

conceals .this volution. The distance across the preceding 

volution from suture to suture is less than one-half its involution. The venter is flat and narrow, forming square shoulders 

with the side walls. The shell is very thin and smooth. The 

living chamber is unknown.

The sutures are lanceolate, with sharply rounded to slightly 

angular saddles and tongue-shaped lobes, mostly bifid with one 

medial lateral trifid. The ventral saddle is very simple, with 

two slight lobate irregularities. The first lateral adventitious 

lobe is short, narrow, and simple and is situated at the ventral 

shoulder; the second lateral is slightly notched; the third and 

fourth are forked, with the latter being the larger. The first 

lateral lobe, which is medial on the side wall, is tripartite. It 

is well developed, much longer than any of the others, and distinctly different. The second lateral lobe is bipartite with 

each of the prongs bifid, so that there are four denticulations 

present. The central notch is nearly three times as deep as 

the lateral notches. The first auxiliary is bifid, which is followed 

by a series of lobes decreasing in size. There are 10 auxiliaries 

in all. . This species differs from Cordillerites angulatus Hyatt and 

Smith by being greatly compressed, with narrow venter and 

with the second lateral lobe bifid with each lateral prong 

notched.

Horizon and locality: Found only in the upper Anasibirites 

beds, Pinecrest formation, Baffle Ridge, Fort Douglas Military 

Reservation, Utah.

Clan GASTRIOCERATEA

Superfamily ARCESTOIDEA

Forms with long body chamber, smooth subglobose 

whorls, and septa either goniatitic, ceratitic, or ammonitic, of the brachyphyllic type. The Arcestoidea 

seem to be derived from the gastrioceran branch of 

the Glyphioceratidae, probably from Adrianites or 

Agathiceras. Under this group belong the Cyclolobidae, Arcestidae, Cladiscitidae, and Ptychitidae.

Family CYCLOLOBIDAE 

Genus PROSPHINGITES Mojsisovics

1886. Prosphingites. Mojsisovics, ArktischeTriasfaunen: Acad. 

imp. sci. St.-Pe'tersbourg M6m., 7th ser., vol. 33, 

No. 6, p. 64.

1905. Prosphingites. Hyatt and Smith, The Triassic cephalopod genera of America: U. S. Geol. Survey Prof. 

Paper 40, p. 72.

Type: Prosphingites czekanowskii Mojsisovics.65

Subglobose, laterally compressed, with helmetshaped whorls and highly arched venter. Umbilicus 

deep and showing the inner volutions.

Surface smooth, except the cross striae of growth.

Septa consisting of an external and two lateral serrated lobes, and a fourth lobe, goniatitic in character, 

on the umbilical border. Internal lobes consisting of 

a long, serrated antisiphonal and two or more narrow 

laterals on each side.

Horizon and locality: Prosphingites is known only 

in the Lower Triassic and up to the present only from

is Mojsisovics, E. von, Arktische Triasfaunen: Acad. imp. sci. St.-P6tersbourg 

M6in., 7th ser., vol. 33, No. 6, p. 64, pi. 15, figs. 10-12,1886.
98

the Arctic-Pacific regions. A single species has been 

found in the Lower Triassic of California.

Prosphingites austini Hyatt and Smith

Plate 7, Figures 1-4

1905. Prosphingites austini. Hyatt and Smith, The Triassic 

cephalopod genera of America: U. S. Geol. Survey 

Prof. Paper 40, p. 72, pi. 7, figs. 1-4.

Shell subglobose, rather involute, with helmetshaped whorls, impressed to about half their height 

by the inner coils. Surface smooth, except for the 

periodic constrictions or varices that occur to the 

number of six or eight to a volution. External septa 

consisting of a divided antisiphonal lobe, and two 

principal laterals, all serrated, and a third lateral or 

auxiliary, goniatitic. The external lobe is narrow, and 

the first and second laterals are broad and shallow. 

The saddles are entire, rounded, and broader than the 

lobes. The internal lobes consist of a short antisiphonal, flanked by three laterals.

Named in honor of Mr. S. W. Austin.

Horizon and locality: In the Lower Triassic Meekoceras zone on Union Wash, 3 miles east of Skinner's 

ranch, Inyo Range, Inyo County, Calif.

Family PTYCHITIDAE

The Ptychitidae are represented by the subfamily 

Nannitinae, with Nannites, Paranannites, and Paraganides, and by the subfamily Ptychitinae, with 

Ptychites and Proptychites. ' The Nannitinae are largely 

confined to the Lower Triassic, whereas of the Ptychitinae Proptychites is confined to the Lower Triassic 

and Ptychites is characteristic of the Middle Triassic.

Subfamily NANNITINAE

Involute, robust, subglobose; body chamber short; 

surface nearly smooth but ornamented with periodic 

constrictions. Septa goniatitic or weakly ceratitic. 

Found throughout the Triassic.

This subfamily is composed of Paraganides Hyatt 

and Smith, Nannites Mojsisovics, and Paranannites 

Hyatt and Smith, all represented in the American 

Triassic.

Genus PARANANNITES Hyatt and Smith

1905. Paranannites. Hyatt and Smith, The Triassic cephalopod

genera of America: U. S. Geol. Survey Prof. Paper 40,

p. 80. 

1911. Paranannites. Arthaber, Die Trias von Albanien: Beitr.

Palaontologie Oesterr.-Ungarns u. des Orients, Band

24, p. 220.

Type: Paranannites aspenensis Hyatt and Smith.

Form subglobose, laterally compressed, sides convex, 

venter broadly rounded. Umbilicus narrow; whorls 

involute, deeply embracing.

Surface nearly smooth or ornamented only with 

radial folds or constrictions.

Septa ceratitic, lobes partly serrated, saddles all 

rounded and entire. The external lobe is divided by a 

small siphonal notch into two short branches. The 

lateral lobe is broad and serrated; the small auxiliary 

is serrated on the type species. The internal septa 

are goniatitic, and consist of a rather long antisiphonal 

lobe flanked by a pair of laterals on each side.

The form and surface ornamentation are exactly 

like those of Juvenites, from which Paranannites can be 

distinguished only by its ceratitic septa. It is probably an intermediate form between Juvenites and the 

true Ptychitidae.

Paranannites is known at present only from the 

Lower Triassic Meekoceras zone of southeast Idaho, 

where several species of it occur, together with Juve' 

nites, Meekoceras, Flemingites, Pseudosageceras, Ophiceras, and other genera characteristic of the Lower 

Triassic.

Paranannites aspenensis Hyatt and Smith

Plate 8, Figures 1-15; Plate 73, Figures 1-30

1905. Paranannites aspenensis. Hyatt and Smith, The Triassic 

cephalopod genera of America: U. S. Geol. Survey 

Prof. Paper 40, p. 81, pi. 8, figs. 1-15, pi. 73, figs. 1-30.

Form robust, involute, somewhat compressed laterally. Whorl highly arched, with flattened sides and 

rather broadly rounded venter. Abdominal shoulders 

indistinct. The umbilicus is very narrow, and the 

whorl is deeply embracing and deeply indented by the 

inner volution. The height of the whorl is half of the 

total diameter of the shell; the breadth is slightly less 

than the height; the indentation is somewhat more than 

half the height. The width of the umbilicus is about 

one-eighth of the diameter of the shell.

The surface is nearly smooth but has faint cross 

striae of growth visible only on the shell, which is 

rarely preserved. These striae become later on weak 

folds, giving a sculpture like that of the Glyphioceratidae. There are also a few constrictions, which 

are visible on the cast.

The septa are ceratitic but comparatively simple. 

The' external lobe is divided by a siphonal notch into 

two narrow branches with serrated ends. The lateral 

lobe is broad and deep, with four or five serrations; the 

auxiliary is similar but smaller and also serrated. The 

antisiphonal lobe is long and narrow, not divided, and 

is flanked on each side by a pair of similar smaller 

internal laterals.

In the young stages this species is a typical Juvenites, 

the serration of the lobes beginning at the diameter of 

5 millimeters. In the Juvenites stage the varices are 

much more numerous, and the form is more robust 

than in later life.

Horizon and locality: In the Lower Triassic Meekoceras zone of the Aspen Ridge, Wood Canyon, southeastern Idaho, about 9 miles east of Soda Springs.
PTYCHITIDAE 99

Paranannites columbianus Smith, n. sp.

Plate 32, Figures 11-25

Shell small, high whorled, involute, laterally compressed, with narrow but open umbilicus, rounded 

flanks, and high helmet-shaped venter. Surface with 

very numerous close-set constrictions.

Septa ceratitic, with rounded entire saddles and 

sharply serrated lobes, of which there are a divided 

external, large lateral, small auxiliary, and a divided 

antisiphonal, flanked by two internal laterals.

Parana/unites columbianus is closely related to P. 

aspenensis but differs in its more robust whorl, wider 

umbilicus, and stronger sculpture. It has no close 

resemblance to any other known species of this widely 

distributed genus.

Horizon and locality: Rather common in the Lower 

Triassic Meekoceras zone of southeastern Idaho, at 

locality 1, 5 miles east of Grays Lake; locality 3, head 

of Wood Canyon, 9 miles east of Soda Springs; and 

locality 5, 1 mile east of Hot Springs, at the north end 

of Bear Lake; associated with Meekoceras gracilitatis, 

Flemingites russelli, Hedenstroemia kossmati, Cordillerites angulatus, Lanceolites compactus, Aspenites acutus, 

and other forms.

Paranannites compressus Smith, n. sp.

Plate 31, Figures 19-21

Shell small, involute, laterally compressed, with 

flattened sides, narrow venter with subangular ventral 

shoulders, and narrow umbilicus. Surface shows 

weak constrictions.

Septa ceratitic, with rounded entire saddles and 

serrated lobes, as in all members of the genus.

Paranannites compressus differs from P. aspenensis 

in its smaller size, higher and more compressed whorls, 

flattened narrow venter and weaker sculpture. It 

differs from P. pertenuis in its thicker whorls and 

broader venter.

Horizon and locality: Rather rare in the Lower 

Triassic Meekoceras zone, at locality 3, head of Wood 

Canyon, Aspen Mountains, 9 miles east of Soda 

Springs, southeastern Idaho; associated with Meekoceras gracilitatis, M. mushbachanum, Flemingites russelli, Hedenstroemia kossmati, Aspenites acutus, Pseudosageceras multilobatum, Cordillerites angulatus, Lanceolites compactus, Clypeoceras muthianum, Xenodiscus 

intermontanus, Lecanites arnoldi, and other forms.

Paranannites pertenuis Smith, n. sp.

Plate 31, Figures 13-15

Shell small, involute, laterally compressed, with 

high subrectangular whorl, flattened sides, abrupt 

ventral shoulders, and somewhat flattened venter. 

Septa ceratitic, with rounded entire saddles, and three 

external serrated lobes. Length of body chamber

unknown. Surface with numerous folds and several 

weak constrictions.

Paranannites pertenuis is closely related to P. 

compressus but differs in its greater lateral compression 

and stronger sculpture. It is not nearly related to 

any other known species of this widely distributed 

genus.

Horizon and locality: Very rare in the Lower Triassic Meekoceras zone of southeastern Idaho, at locality 

3, head of Wood Canyon, Aspen Mountains, 9 miles 

east of Soda Springs; associated with Meekoceras 

gracilitatis, M. mushbachanum, Flemingites russelli, 

Hedenstroemia kossmati, Aspenites acutus, Cordillerites 

angulatus, Lanceolites compactus, Ussuria waageni, 

Pseudosageceras multilobatum, and other forms.

Subfamily PTYCHITINAE

Subglobose, laterally compressed, involute forms, 

with short body chamber, and surface ornamented 

only with obscure folds. Septa either ceratitic or 

ammonitic. Venter rarely acute, forming a sort of 

keel, more commonly arched.

All members of this group go through a Nannites 

stage of growth in their youth, but the separation 

from the parent stock must have taken place in Paleozoic time, for typical members of the Ptychitinae are 

present in the Lower Triassic of Asia and America.

This subfamily is represented in the American 

Triassic by three genera Owenites Hyatt and Smith, 

known in the Lower Triassic of California, and in 

Timor; Proptychites Waagen, known in America only 

from the Lower Triassic of California but common in 

the same series in Siberia and India, rare in the 

Middle Triassic of the Alpine province; and Ptychites, 

characteristic of the Middle Triassic in America, Asia, 

and Europe; and probably by a fourth genus, Proteusites Hauer, common in the Middle Triassic of the 

Balkan Peninsula and rare in the Lower Triassic 

Owenites subzone of the Meekoceras zone of California.

Genus OWENITES Hyatt and Smith

1905. Owenites. Hyatt and Smith, The Triassic cephalopod

genera of America: U. S. Geol. Survey Prof. Paper 40,

p. 82. 

1922. Owenites. Welter, Die Ammoniten der Unteren Trias

von Timor: Palaeontologie von Timor, Lief. 11, Abh.

19, p. 151.

Type: Owenites koeneni Hyatt and Smith.

Body chamber long, comprising the last volution. 

Form, lenticular, involute, deeply embracing, with 

closed umbilicus, rounded sides, and acute venter 

without any real keel or shoulder angles.

Surface smooth or ornamented with radial folds, 

occasionally with bundled ribs, which run straight up 

the sides and become obsolete on the venter.

Septa ceratitic, the saddles mostly rounded, the 

lobes serrated. The siphonal saddle may occasionally
100 LOWER TRIASSIC AMMONOIDS OF NORTH AMERICA

be digitate but is generally entire. There are no 

adventitious lobes. The external and the two principal laterals are similar, usually short and rather wide. 

Some species have a third lateral before the auxiliary 

series, which is composed of two or more denticulations, becoming with age independent auxiliaries but 

never serrated. The internal lobes and saddles are 

also very numerous. This genus resembles Hungarites 

but differs in lacking the abdominal shoulder angles 

arid in having the young globose and involute, with 

Nannites form and septa. It is therefore classed in the 

Ptychitidae as a descendant of Nannites. The young 

also possess rather strong radial ribs and constrictions, 

wholly unlike the young stages of any of the true 

Ceratitoidea. Toula 66 has described from the lower 

Muschelkalk of Asia Minor some species which he 

assigned to Hungarites but which are said to have 

globose young. In form and septa they resemble 

Owenites, and it is quite possible that this genus has 

lasted into the Middle Triassic in that region.

Owenites has a strong external resemblance to 

Dalmatites Kittl,67 which that author assigned to the 

Hungaritidae, but the European genus differs from the 

American in lacking the auxiliary lobes. Kittl regarded Dalmatites as nearly related to the radicle of 

the Hungaritidae, whereas the ontogeny of Owenites 

shows that it does not belong to the Hungaritidae and 

that it is rather closely related to definite members of 

the Ptychitidae.

Owenites is known at present from the Lower Triassic Owenites subzone of the Meekoceras zone of the 

Inyo Range, Inyo County, Calif., where several species 

have been found, besides Owenites koeneni; it is also 

fairly common and characteristic of the Lower Triassic 

Owenites zone of Timor, in the East Indies.

Owenites carpenter! Smith, n. sp.

Plate 54, Figures 31-34

Shell small, involute, laterally compressed, with 

closed umbilicus, flattened sides, and blunt subangular 

venter. Surface ornamented with rather strong bundled radial ribs. Septa ceratitic, with an external 

divided lobe, larger first lateral, smaller second lateral, 

and short series of several small auxiliaries. The 

siphonal saddle that divides the external lobe shows a 

tendency to form adventitious lobes, as is frequently 

seen in members of the Meekoceratidae. But the young 

of this species are like Juvenites with gastrioceran septa 

and with well-defined ribs and constrictions, and it must 

be assigned to the Ptychitidae.

Owenites carpenteri is not closely related to any 

other known members of the genus, differing from all

86 Toula, F., Eine Muschelkalkfauna am Golfe von Ismid in Kleinasien: BeitrPalaontologie Oesterr.-Ungarns u. des Orients, Band 10, Heft 4, p. 176, 1896.

87 Kittl, Ernst, Die Cephalopoden der oberen Werfener Schichten von Muc in 

Dalmatien: K.-k. geol. Reichsanstalt Wien Abh., Band 20, Heft 1, p. 72, 1903.

in the bluntness of the venter and in the stronger 

sculpture.

Named in honor of Philip P. Carpenter, who after 

60 years still exerts a lasting and wholesome influence 

on the study of American paleontology.

Horizon and locality: Rather rare in the Lower 

Triassic Owenites subzone ot the Meekoceras zone, of 

Union Wash, Inyo Mountains, Inyo County, Calif., 

about 15 miles southeast of Independence; associated 

with Meekoceras gracilitatis, Owenites koeneni, Lecanites 

arnoldi, Xenodiscus waageni, Anasibirites desertorum, 

A. noetlingi, Lanceolites compactus, Pseudosageceras 

multilobatum, Inyoites oweni, and other forms.

Owenites egrediens Welter

Plate 52, Figure 6-8

1922. Owenites egrediens. Welter, Die Ammoniten des Unteren 

Trias von Timor: Palaeontologie von Timor, Lief. 

11, Abh. 19, p. 151, pi. 168, figs. 22-29, and text 

figs. 14-18.

Form robust, lenticular, with narrow egredient 

umbilicus and arched whorls, curving to the steep, 

roof-shaped venter. Surface with very fine curved 

striae of growth, and nearly obsolete folds. Septa 

ceratitic, with rounded entire saddles and four external 

serrated lobes, of which the fourth, next to the umbilicus, is broken up into a short auxiliary series.

Until the diameter of 20 millimeters is reached the 

umbilicus is closed and at this stage begins to egress, 

the egression being more pronounced in age.

Owenites egrediens is rather closely related to 0. 

koeneni, differing in its more robust shell, greater 

egression of the whorl, and simpler septa.

Horizon and locality: Owenites egrediens was first 

found in the Lower Triassic Owenites zone of Timor; 

it is rather rare in the Lower Triassic Owenites subzone of the Meekoceras zone of Union Wash, Inyo 

Mountains, about 15 miles southeast of Independence, 

Inyo County, Calif., associated with Meekoceras 

gracilitatis, Owenites koeneni, Lanceolites bicarinatus, 

Pseudosageceras multilobatum, Sturia compressa, Juvenites dienerl, and other forms.

Owenites koeneni Hyatt and Smith

Plate 10, Figures 1-22

1905. Owenites koeneni. Hyatt and Smith, The Triassic 

cephalopod genera of America: U. S. Geol. Survey 

Prof. Paper 40, p. 83, pi. 10, figs. 1-22.

Form involute, laterally compressed, lenticular. 

Whorl deeply embracing and deeply indented by the 

inner volutions; sides flattened-convex, curving without abdominal shoulders to the acute venter. There is 

no keel, but the abdomen grows gradually narrower 

until it resembles a keel. Umbilicus narrow, growing 

wider with age. The height of the last whorl is half 

the total diameter, and the indentation or involution is
PTYCHITIDAE 101

half the height. The width of the whorl is threefifths of the height. The width of the umbilicus is abo at 

one-sixth of the total diameter.

The surface of the shell and of the cast is smooth at 

maturity, being destitute of ribs, constrictions, or 

other ornamentation.

The septa are ceratitic, the saddles are all rounded 

and entire, the lobes all serrated. The external lobe 

is divided by a siphonal notch or saddle into two short 

branches; the first lateral is similar but larger; the 

second lateral is similar to the first but only two-thirds 

of its size. First auxiliary bifid, each of the small 

divisions being serrated; second auxiliary undivided 

but serrated. Antisiphonal lobenarrowand undivided, 

flanked by five internal lobes on each side.

In the young stages the whorl is rounded, robust, 

with rounded venter, constrictions, and radial ribs. 

In this stage it resembles Juvenites in form and the 

simple septa. The venter becomes acute at the diameter of about 6 millimeters; the constrictions cease and 

the ribs become less distinct at 8 millimeters, and the 

septa cease to be goniatitic and become serrated at 

about 10 millimeters. From this stage onward no 

change in development takes place, except in the widening of the umbilicus at maturity.

Owenites koeneni resembles Hungarites but differs 

externally from that genus in its merely sharpened 

venter, without abdominal shoulder angles. The 

inner volutions, however, show still greater differences, 

being involute and rounded, like Juvenites, the radicle 

of the Ptychitidae, instead of evolute and discoidal, 

like the young of the Ceratitoidea.

The only species with which Owenites koeneni may 

be compared is 0. egrediens of the same fauna, from 

which it differs in greater involution, more compressed 

form, and more complex septa.

."Horizon and. locality: Owenites koeneni was found by 

J. P. Smith in the Lower Triassic Owenites sub zone of 

the Meekoceras zone of the Inyo Range, 1% miles east 

of Union Spring, on the old McAvoy trail across to 

Saline Valley, about 15 miles southeast of Independence, Inyo County, Calif.

Owenites zitteli Smith, n. sp.

Plate 52, Figures 1-5

Form involute, narrowly umbilicate, sides flattened, 

sloping rather abruptly to the umbilicus and very gently 

to the high, narrow venter, which is extended in a 

rather sharp keel. Surface at maturity nearly smooth, 

except for the fine growth lines. Septa ceratitic, with 

the divided ventral lobe narrow, tongue-shaped, and 

longer than the first lateral; there is also a smaller 

second lateral and a long series of auxiliaries. The 

ventral saddle shows on the siphonal side a small 

notch that resembles an incipient adventitious lobe.

Body chamber at least a revolution long.

Owenites zitteli resembles 0. koeneni, the genotype, 

but differs in its greater compression, higher whorl, 

sharper keel, and more complicated septa. Its young 

stages are like those of 0. koeneni, with gastrioceran 

septa, ribs, and constrictions.

Named in memory of Karl A. von Zittel.

Horizon and locality: Rare in the Lower Triassic 

Ownites subzone of the Meekoceras zone, of Union 

Wash, Inyo Mountains, about 15 miles southeast of 

Independence, Inyo County, Calif.; associated with 

Meekoceras gracilitatis, Owenites koeneni, Lecanites 

arnoldi, Xenodiscus waageni, Anasibirites desertorum, 

A. noetlingi, Lanceolites compactus, Sturia compressa, 

Pseudosageceras multilobatum, Inyoites oweni, and 

other forms.

Genus PROPTYCHITES Waagen

1892. Proptychites. Waagen, India Geol. Survey Rec., vol. 

25, p. 183.

1892. Proptychites. Waagen, K.-k. geol. Reichsanstalt Wien 

Jahrb., Band 42, p. 379.

1895. Proptychites. Waagen, Fossils from the Ceratite formation: India Geol. Survey Mem., Palaeontologia Indica, 

13th ser., Salt Range fossils, vol. 2, p. 162.

1895. Proptychites. Diener, Triadische Cephalopodenfaunen 

der ostsibirischen Kustenprovinz: Com. g<5ol. [St.- 

P6tersbourg] Mem., vol. 14, No. 3, p. 31.

1897. Proptychiles. Diener, Cephalopoda of the Lower Trias: 

India Geol. Survey Mem., Palaeontologia Indica, 

15th ser., Himalayan fossils, vol. 2, pt. 1, p. 70.

1902. Aspidites (part). Frech, Lethaea geognostica, Teil 1, 

Das Palaeozoicum, Band 2, Lief. 4, p. 637.

1905. Proptychites. Hyatt and Smith, The Triassic cephalopod 

genera of America: U. S. Geol. Survey Prof. Paper 40, 

p. 84.

1911. Proptychites. Arthaber, Die Trias von Albanien: Beitr. 

Palaontologie Oesterr.-Ungarns u. des Orients, Band 

24, p. 221.

Type: "Ceratites" lawrencianus De Koninck, 68 from 

the Lower Triassic of the Salt Range.

Form thickly lenticular, robust, with narrow umbilicus, flattened sides, and broadly rounded venter. 

Surface smooth or ornamented with faint radial folds. 

Septa distinctly ceratitic, the saddles long, narrow, 

and rounded, the lobes usually broader and serrated. 

There is usually an external lobe divided by a rather 

deep siphonal saddle, two principal laterals, and an 

auxiliary series, which may consist of a single ceratitic 

lobe or a series of denticulations, some of which may 

become individualized into secondary lobes. The 

internal septa consist of an antisiphonal lobe, with a 

single lateral.

Mojsisovics69 classes Proptychites lawrencianus under 

Meekoceras, whereas Griesbach classes it with Ptychites. 

But the young of Proptychites are said to be invariably 

globose, of the Nannites type, and the mature forms

"8 De Koninck, L. G., Descriptions of some fossils from India: Geol. Soc. London 

Quart. Jour., vol. 19, p. 14, pi. 6, fig. 3, 1863.

M Mojsisovics, E. von, Arktische Triasfaunen: Acad. imp. sci. St.-P6tersbourg 

Mem., 7th ser., vol. 33, No. 6, p. 79, 1886.
102 LOWER TRIASSIC AMMONOIDS OF NORTH AMERICA

invariably have ceratitic septa characters which distinguish Proptychites from those two genera. Waagen 

considers this genus the ancestor of Ptychites, although 

he knew of no transitional forms between the two.

Frech 70 proposes to drop the genus Proptychites and 

to assign all the species of this group to Aspidites. 

The writer is of the opinion that this view is probably 

correct, but a further study of the ontogeny of the two 

genera would be necessary before such a reference 

could be decisive. Waagen was of the opinion that 

Proptychites was an ancestral form of the Ptychitidae, 

but Frech believes that this family was not differentiated before the Middle Triassic. Mojsisovics, Diener, 

and the writer, however, agree in regarding Nannites 

as the ancestor of Ptychites.

Proptychites is almost exclusively confined to the 

Lower Triassic, being found at that horizon in the Salt 

Range and the Himalayas in India, at Ussuri Bay in 

eastern Siberia, and in the Owenites subzone of the 

Meekoceras zone of Inyo County, Calif. Proptychites 

walcotti is the only species known to occur in America.

Proptychites walcotti Hyatt and Smith

Plate 19, Figures 1-7; Plate 52, Figures 18-20

1905. Proptychites walcotti. Hyatt and Smith, The Triassic 

cephalopod genera of America: U. S. Geol. Survey 

Prof. Paper 40, p. 85, pi. 19, figs. 1-7.

Robust, involute, deeply embracing, laterally compressed, abdomen rounded so that there are no shoulders. Outer whorl twice as high as broad, embracing 

about half the inner and being indented to about onefourth the height by it. Umbilicus narrow, only about 

one-sixth of the diameter. Umbilical shoulders abrupt, 

almost angular.

Surface smooth, so far as known.

Septa ceratitic, with rounded, entire, and constricted 

saddles and serrated lobes. External lobe divided 

into two very broad branches by a broad, digitate 

siphonal saddle; the first lateral lobe is twice as long as 

the external and serrated not only on the ends but also 

more than halfway up its sides; second lateral about 

the size of the external; auxiliary series, consisting of 

four or five denticulations forming a broad lobe, somewhat after the manner of Clypeoceras (Aspidites) "but 

perfectly regular. Internal septa not seen in detail 

but consisting of a large antisiphonal and one smaller 

lateral. The form and septa greatly resemble those of 

"Paranorites" ambiensis Waagen 71 but differ in being 

more robust, having narrower umbilicus, and having 

fewer denticulations on the auxiliary series. This 

species might well be assigned to Paranorites, but that 

genus is probably based merely on a highly specialized 

form of Proptychites. The present species also resem10 Frech, Fritz, Lethaea geognostica, Teil 1, Das Palaeozoicum, Band 2, Lief. 4, 

p. 637. 1902.

71 Waagen, W., Fossils from the Ceratite formation: India Oeol. Survey Mem., 

Palaeontologia Indica, 13th ser., Salt Range fossils, vol. 2, p. 158, pi. 22, fig. 1, 1895.

bles somewhat Proptychites khoorensis Waagen 72 but 

has the septa much more specialized, as the ventral 

saddle is digitate and the serrations are not confined 

to the ends of the lobes. This sort of digitation of the 

lobes and the bases of the saddles is quite common in 

Proptychites but does not seem to be transitional to 

Ptychites. The writer has not yet had the opportunity 

to study the complete ontogeny of this genus but is of 

the opinion that it will turn out to be a member of 

the Meekoceratidae, which it so greatly resembles 

that even Mojsisovics has not been able to draw a 

line between them. It seems to be more nearly 

related to Clypeoceras than to any other member of 

the group and may be the ancestral form of that genus. 

Horizon and locality: Proptychites walcotti was 

found by J. P. Smith in the Owenites subzone of the 

Lower Triassic Meekoceras zone of Union Wash, Inyo 

Range, east side of Owens Valley, about 15 miles 

southeast of Independence, Inyo County, Calif., associated with Meekoceras gracilitatis White and M. 

(Koninckites) mushbachanum White.

Genus PROTEUSITES Hauer

1887. Proteusites. Hauer, Die Cephalopoden des bosnischen 

Muschelkalkes von Han Bulog bei Sarajevo: K. Akad. 

Wiss. Wien Denkschr., Band 54, p. 27.

1892. Proteusiles. Hauer, Beitrage zur Kenntniss der Cephalopoden aus der Trias von Bosnien, I: K. Akad. Wiss. 

Wien Denkschr., Band 59, p. 267.

1905. Proteites. Diener, Entwurf einer Systematik der Ceratitiden des Muschelkalkes: Akad. Wiss. Wien Sitzungsber., Band 114, p. 797.

1915. Proteites. Diener, Fossilium Catalogus, pt. 8, Cephalopoda Triadica, p. 233.

Type: Proteusites kellneri Hauer 73 from the Middle 

Triassic of the Balkan Peninsula.

Form robust, subrotund, with rather wide umbilicus 

and rounded whorls. Surface with umbilical ribs and 

nodes prolonged up the flanks. Some species show 

spiral lines on the shell. Septa ceratitic on the type 

but slightly ammonitic on some species. Length of 

body chamber unknown.

This genus was assigned by F. von Hauer to the 

Ceratitidae, but its form and sculpture point certainly 

to a derivation from the Glyphioceratidae and to kinship with either the Tropitidae or the Ptychitidae, 

probably the latter.

Horizon and locality: Common in the Middle Triassic of the Balkan Pennisula; rare in the Lower 

Triassic Owenites subzone of the Meekoceras zone of 

Inyo County, Calif.

Proteusites rotundus Smith, n. sp.

Plate 53, Figures 5-8

Shell of moderate size, robust, subrotund, somewhat 

evolute, little embracing; with helmet-shaped whorls,

72 Idem, p. 176, pi. 20, flg. 4.

73 Hauer, F. von, Die Cephalopoden des bosnischen Muschelkalkes von Han 

Bulog bei Sarajevo: K. Akad. Wiss. Wien Denkschr., Band 54, p. 27, pi. 7, figs. 1-4, 

1887.
CELTITIDAE 103

rounded and broad. Surface with strong, straight umbilical ribs, running more than halfway up the flanks, 

and crossed by fine, strong transverse striae. Septa 

ceratitic, with entire saddles and four external serrated 

lobes. No spiral striae are visible on the specimens at 

hand, but they would hardly be preserved.

The height of the last whorl is two-fifths of the 

diameter of the shell; the width is more than threefourths of the height; the width of the umbilicus is more 

than one-third of the diameter of the shell.

Proteusites rotundus is not nearly related to any of the 

Middle Triassic members of the genus, the only ones 

known up to this time.

Horizon and locality: Rare in the Lower Triassic 

Owenites subzone of the Meekoceras zone, in Union 

Wash, Inyo Mountains, about 15 miles southeast of 

Independence, Inyo County, Calif.; associated with 

Meekoceras gracilitatis, Owenites koeneni, Inyoites 

oweni, Lanceolites bicarinatus, Aspenites acutus, Pseudosacjeceras multilobatum, Anasibirites desertorum, A. 

noetlingi, and other forms.

TROPITOIDEA

Forms with long body chamber, ammonitic, rarely 

goniatitic, simple septa, strong sculpture, either lateral 

ribs, or spines, or ventral keel. The young are involute 

and subglobose, resembling in form and septa the 

Carboniferous family Glyphioceratidae. Under this 

group are included the Haloritidae, Tropitidae, and 

Celtitidae.

Family CELTITIDAE

Whorls evolute, slender, rounded or subquadratic in 

cross section, little embracing and little indented by 

the inner whorls.

Surface ornamented with umbilical or lateral ribs 

that usually become obsolete on the flanks, commonly 

also with weak spiral lines. The inner whorls often 

show varices or constrictions. The septa are simple, 

being either goniatitic or weakly serrated. The body 

chamber is long, more than a revolution in length. 

The young stages of all members of this family resemble 

Gastrioceras of the Carboniferous, from which group the 

Celtitidae no doubt descended.

Celtites has usually been regarded as the radicle of the 

Tropitidae, but the writer is of the opinion that, 

although it is nearly related to the ancestral stock of 

Tropites, it should rather be regarded as a lateral 

branch, degenerate in character. The earlier species 

of Celtites may have been connecting links between 

Gastrioceras and Columbites, but the species found in 

the higher horizons of the Triassic are merely littlemodified survivors.

Hyatt and Smith n placed the Celtitidae under the 

Ceratitoidea, but this was done because of the inclusion

74 Hyatt, Alphous, and Smith, J. P., The Triassic cephalopod genera of America: 

U. S. CI col. Survey Prof. Paper 40, p. 121,1905.

of Xenodiscus in the family. It is pretty generally 

agreed now that Xenodiscus is allied to the group of 

Meekoceras and Ceratites and has no kinship with the 

true Celtitidae.

The Celtitidae, in the restricted sense, are represented in America by Celtites and Columbites in the 

Lower and Middle Triassic. Tropigastrites Smith might 

also be included in the family, but its more complex 

septa and its high acute venter show greater affinity 

to the Tropitidae and afford a connecting link between 

Columbites and Tropites.

Hauer has described, from the Middle Triassic of 

Bosnia, the genus Proteusites,'15 with which also the 

group of "Ceratites" decrescens Hauer may be united. 

This group is characterized by robust form, wide 

umbilicus, semilunar cross section, strong lateral ribs, 

many constrictions, ceratitic or brachyphyllic septa, 

and semiglobose young. These forms certainly do 

not belong to the Ceratitoidea but are descendants of 

the stock of Glyphioceratidae. Philippi 76 is inclined 

to unite Proteusites and its kindred with the Arcestidae, but the strong sculpture in youth as well as 

age would forbid this. All the characters of Proteusites remind one strongty of Columbites, and this is 

especially true of Proteusites striatus Hauer, 77 which 

agrees with Columbites in the lateral ribs, evolute 

whorl, and spiral lines on the shell and differs only in 

its more numerous lobes and brachyphyllic saddles. 

The writer is of the opinion that Proteusites is a littlemodified descendant of Columbites and a parallel development with Tropigastrites. Celtites and Columbites are not found below the Triassic.

Genus CEITITES Mojsisovics

1882. Celtites. Mojsisovics, Cephalopoden der Mediterranen 

Triasprovinz: K.-k. geol. Reichsanstalt Wien Abh., 

Band 10, p. 145.

1892. Celtites. Hauer, Beitiiige zur Kenntniss der Cephalopoden der Trias von Bosnien, I: K. Akad. Wiss. 

Wien Denkschr., Band 59, p. 273.

1893. Celtites. Mojsisovics, Die Cephalopoden der Hallstiitter Kalke: K.-k. geol. Reichsanstalt Wien Abh., 

Band 6, Halfte 2, p. 346.

1905. Celtites (part). Hyatt and Smith, The Triassic cephalopod genera of America: U. S. Geol. Survey Prof. 

Paper 40, p. 125.

1911. Celtites (part). Arthaber, Die Trias von Albanien: 

Beitr. Puliiontologie Oesterr.-Ungarns u. des Orients, 

Band 24, p. 266, 1911.

1914. Celtites. Smith, The Middle Triassic marine invertebrate faunas of North America: U. S. Geol. Survey 

Prof. Paper 83, p. 34.

"5 Hauer, F. von, Die Cephalopoden des bosnischen Muschelkalkes von Han 

Bulog bei Sarajevo: K. Akad. Wiss. Wien Denkschr., Band 54, p. 27, 1887.

"6 Philippi, E., Die Ceratiten des oberen deutschen Muschelkalkes: Palaeont. 

Abh. (Dames & Koken), new ser., Band 4, p. 438, 1901.

" Hauer, F. von, Beitrfige zur Kenntniss der Cephalopoden aus der Trias von 

Bosnien, I: K. Akad. Wiss. Wien Denkschr., Band 59, p. 263, pi. 4, figs, la-c, 1892.
104 LOWER TRIASSIC AMMONOIDS OF NORTH AMERICA

Not 1895. Celtites. Waagen, Fossils from the Ceratite formation: India Geol. Survey Mem., Palaeontologia 

Indica, 13th ser., Salt Range fossils, vol. 2, p. 69.

Not 1906. Celtites. Koken, in Noetling, Die asiatische Trias: 

Lethaea geognostica, Teil 2, Das Mesozoicum, Band 1, 

Trias, pi. 22 and explanation of plate.

Type: "Trachyceras" epolense Mojsisovics. 78 

Whorls evolute, little embracing, low, increasing 

very slowly in height. Cross section quadratic, sides 

flattened, abdominal shoulders abruptly rounded, 

venter flattened. Sides ornamented with simple 

straight ribs that become obsolete at the shoulders. 

Fine spiral lines appear on the venters of some species, 

and occasionally the sculpture crosses the venter in 

old age. Body chamber long. Septa goniatitic. 

Ventral lobe generally divided but in some specimens 

undivided. There are usually two laterals and an 

auxiliary. Antisiphonal lobe divided.

Celtites ranges from the bottom to the top of the 

Triassic. In America it has been found .in the Middle 

Triassic of the West Humboldt Range of Nevada, two 

species having been described from that place. Several species occur in the Lower Triassic of southeast

Idaho.

Celtites apostolicus Smith, n. sp.

Plate 48, Figures 1-10

Shell small, evolute, widely umbilicate; whorls with 

subquadratic section, higher than wide, very slender, 

and increasing very slowly in size. Surface with 

weak constrictions curving forward in a broad sinus 

on the venter; also with very fine spiral lines. In 

youth these are weak umbilical nodes, becoming obsolete with age. Septa goniatitic, with divided 

ventral lobe, larger lateral, small auxiliary; narrow 

antisiphonal lobe, with small internal lateral.

Celtites apostolicus is very closely related to C. 

ursensis, with which it is associated, differing only in 

the higher and more slender whorl. It agrees perfectly with that species in its long body chamber, 

almost obsolete sculpture and gastrioceran septation. It, too, is little modified from the ancestral 

Gastrioceras from which it must have sprung.

Horizon and locality: Rather common in the 

Lower Triassic Columbites zone of Paris Canyon, 1 

mile west of Paris, Idaho; associated with Meekoceras 

pilatum, Columbites parisianus, C. spencei, Ophiceras 

spencei, Pseudharpoceras idahoense, Celtites planovolvis, C. ursensis, and other forms.

Celtites planovolvis Smith, n. sp.

Plate 48, Figures 11-20

Shell small, evolute, widely umbilicate; whorls low 

and flattened, wider than high, with broad subquad-

 "8 Mojsisovics, E. von, Die Dolomitriffe von Siidtirol und Venetien, p. 57, 1878; 

Die Gephalopoden der Mediterranen Triasprovinz: K.-k. geol. Eeichsanstalt Wien 

Abh., Band 10, p. 149, pi. 29, figs. 1, 2; pi. 38, fig. 13, 1882.

ratio section, subangular shoulders, narrow flanks and 

flattened venter. Surface with very weak constrictions 

and fine spiral lines, stronger in youth, becoming almost 

obsolete with age. Septa goniatitic, with divided ventral lobe, larger lateral, small auxiliary and tongueshaped antisiphonal, flanked by a small lateral.

Dimensions of a large specimen of Celtites .planovolvis

Millimeters 

Diameter. ____-______.-:-_____-__--___ 33

Height of last whorl.___________________ 7. 5

Height of last whorl from the preceding _ _ 6 

Width of last whorl______ -.__ ._______ 9. 5

Width of umbilicus______-_-_-_________ 19.5

Celtites planovolvis is closely related to C. ursensis, 

from which it differs in its lower and broader whorl; 

from C. apostolicus it differs in the same characters 

but to a much greater degree. It is not nearly related 

to any other known species of Celtites, but its form, 

sculpture, and septation suggest a very decided kinship 

with the ancestral Gastrioceras or Paragastrioceras.

Horizon and locality: Rather rare in the Lower 

Triassic Columbites zone of Paris Canyon, 1 mile west 

of Paris, Idaho; associated with Meekoceras pilatum, 

Columbites parisianus, C. spencei, Ophiceras spencei, 

Pseudharpoceras idahoense. Celtites ursensis, C. apostolicus, and other forms.

Celfites ursensis Smith, n. sp.

Plate 47, Figures 11-23

Shell small, evolute, widely umbilicate; whorls subquadratic in section, with flattened sides, gently arched 

venter, and subangular ventral and umbilical shoulders, 

slightly higher than wide; little embracing, and increasing very slowly in height. Surface with weak 

lateral folds and constrictions that curve forward on 

the flanks and become nearly obsolete on the venter; 

also faint spiral lines on the shell and the cast. Septa 

goniatitic, with a ventral lobe divided into two narrow 

branches, a larger lateral, small auxiliary on the umbilical slope, and a longer bifid antisiphonal lobe flanked 

by a small internal lateral.

Length of body chamber greater than a revolution.

Dimensions of a large specimen of Celtites ursensis

Millimeters 

Diameter. __-_-____-__-_--_______-'-_-_ 42

Height of last whorl____.._ _______________ 10

Height of last whorl from the preceding.-_ 9 

Width of last whorl.___________________ 9

Width of umbilicus-___________________ 25

Celtites ursensis is closely related to C. planovolvis of 

the same fauna but differs in its narrower and .higher 

whorl; from C. apostolicus, also of the same fauna, it 

differs in its broader and squarer whorl. C. ursensis 

has some remote kinship with C. polyyyratus Smith, of 

the Middle Triassic of Nevada, but differs in its more 

robust whorl and weaker sculpture.
CELTITIDAE 105

Horizon and locality: Rather common in the Lower 

Triassic Columbites zone, Paris Canyon, 1 mile west of 

Paris, Idaho; associated with Columbites parisianus, 

C. spencei, Meekoceras pilatum, Ophiceras spencei, 

Pseudharpoceras idahoense, Celtites apostolicus, C. planovolvis, etc.

Genus COLUMBITES Hyatt and Smith

1905. Columbites. Hyatt and Smith, The Triassic cephalopod 

genera of America: U. S. Geol. Survey Prof. Paper 40, 

p. 50.

1908. Columbites. Arthaber, Uebcr die Entdeckung von Unter 

Trias in Albanian und ihre faunistische Bewertung: 

Geol. Gesell. Wien Mitt., Band 1, p. 276.

1911. Columbites. Arthaber, Die Trias von Albanien: Beitr. 

Paliiontologie Oesterr.-Ungarns u. des Orients, Band 

24, p. 260.

1914. Columbites. Smith, The Middle Triassic marine invertebrate faunas of North America: U. S. Geol. Survey 

Prof. Paper S3, p. 36.

Not .1.922. Columbites. Welter, Die Ammoniten der Untereri 

Trias von Timor: Palaeontologie von Timor, Lief. 11, 

Abh. 19, p. 150.

Type: Columbites parisianus Hyatt and Smith.

Form evolute, discoidal; whorls little embracing 

and little impressed by the inner volutions, low and 

increasing slowly in height. Cross section helmet 

shaped. Umbilicus wide. Body chamber at least one 

revolution in length. Surface ornamented with lateral 

ribs, spiral striae, and many constrictions.

Septa consisting of a divided ventral lobe, a principal lateral lobe, and an auxiliary. Internal septa 

consisting of a narrow antisiphonal lobe flanked by a 

similar lateral on each side. The divided ventral 

lobe and the principal lateral are slightly serrated, 

the other lobes and all the saddles are goniatitic, 

except the auxiliary lateral lobe, which is occasionally 

serrated.

In adolescence the whorl is trapezoidal in shape and 

is much broader and more depressed than at maturitj^. 

At this stage the septa are goniatitic, and all the 

characters resemble Gastrioceras of the Carboniferous, 

from which genus Columbites seems to have originated, 

and it is probably a connecting link between the 

Tropitidae of the Triassic and the Glyphioceratidae of 

the Carboniferous.

For a long time Celtites has been regarded by some 

paleontologists as the ancestor of the Tropitidae, in 

spite of the fact that no certain members of the Tropitidae were known to have young stages resembling 

Celtites. This was because the ontogeny of the Tropitidae points to an evolute ancestor with long body 

chamber and lateral ribs and destitute of keel and 

abdominal furrows. Columbites meets these requirements and is like the young stages of the more primitive members of the Tropitidae, whereas Celtites is 

somewhat retrograde and almost too primitive to be 

the radicle.

Columbites is apparently tending directly toward the 

Tropitidae. In its youth it is decidedly like Gastrioceras and Paragastrioceras and in adolescence takes on 

the serration of the lobes. The development of two 

species of this genus has been fully described by the 

writer, 79 and the young stages of C. parisianus Hyatt 

and Smith and of C. spencei Smith fully figured, with 

detailed comparisons with Gastrioceras. Arthaber 80 

has described from Albania several species of Columbites 

that appear to approach more nearly to Tropites than 

the American species do, in spite of the somewhat 

adverse opinion of that author. At that time Arthaber 

could not know of the intergradation of Columbites 

and Tropicjastrites, which was not published until 1914 

and was consequently inaccessible to him for several 

years.

The writer does not mean to assert that any known 

species of Columbites in either the American or the 

Albanian fauna was the ancestor of Tropites but that 

something like a Columbites certainly was.

Columbites is chiefly characteristic of the lower 

Triassic Columbites zone of Idaho and Albania, but 

some retarded species are found in the middle Triassic 

of Nevada. It has been assumed by Mojsisovics 8l 

that the Tropitidae developed out of Gastrioceras, of 

the Carboniferous, in spite of the enormous gap that 

existed from Permian to Upper Triassic. It was 

supposed that Paraceltites, of the Permian, and Isculites, of the Middle Triassic, partly filled the gap, but 

the former genus is now assigned to Xenodiscidae and 

the latter to Haloritidae. The writer 82 has described 

several species of Columbites from the Lower Triassic 

of Ida.ho.

Arthaber 83 recognized Columbites as a common member of the Lower Triassic fauna of Albania, and along 

with it he described the genus Protropites, 84 which in 

his opinion has even greater right than Columbites to 

be considered the radicle of the Tropitidae. It is 

certainl}7" true that the late larval stages of Tropites 

subbullatus, Paratropites sellai, and Discotropites sandlingensis, as figured by the writer 85 six years before the 

publication of Arthaber's work, resemble greatly the 

adults of Protropites. The writer accepts Protropites

"» The Triassic cephalopod genera of America: U. S. Geol. Survey Prof. Paper 40, 

p. 51, 1905; The Middle Triassic marine invertebrate faunas of North America: 

U. S. Geol. Survey Prof. Paper 83, pp. 36, 37, 1914.

8° Arthaber, G. von, Die Trias von Albanien: Beitr. Paliiontologie Oesterr.- 

Ungarns u. des Orients, Band 24, pp. 200-204, 1911.

61 Mojsisovics, E. von, Die Cephalopoden der IIallstatter Kalke: K.-k. geol. 

Reichsanstalt Wien Abh., Band 0, Hfilfte 2, p. 7, 1893.

52 Smith, J. P., The Triassie cephalopod genera of America: U. S. Geol. Survey 

Prof. Paper 40, p. 50, 1905; The Middle Triassic marine invertebrate faunas of 

North America: U. S. Geol. Survey Prof. Paper 83, p. 30, 1914.

53 Arthaber, G. von, op. cit. (Die Trias von Albanien), p. 201.

E< Idem, p. 255.

M Smith, J. P., The Triassic cephalopod genera of America: U. S. Geol. Survey 

Prof. Paper 40, 1905. (Paratropites sellai, pi. 31, figs. 14-33; Discotropites sandlingensis, pi. 30, figs. 1-9; Tropites subbullatus, pi. 79, figs. 1-0.)
106 LOWER TRIASSIC AMMONOIDS OF NORTH AMERICA

as an ancestral form but considers it a possible link 

between Columbites and Tropigastrites.

Columbites was first described by Hyatt and Smith 

from the Columbites zone, upper part of Lower Triassic, 

of the Wasatch Mountains, in southeastern Idaho. 

In this fauna it is represented by Columbites consanguineus Smith, C. ligatus Smith, C. minimus Smith, 

C. ornatus Smith, C. parisianus Hyatt and Smith, and 

C. spencei Smith.

In the Albanian fauna, at the same horizon, Columbites is represented by C. dusmani Arthaber, C. europaeus Arthaber, C. mirditensis Arthaber, and C. perrini-smithi Arthaber, all apparently more specialized 

than the American type.

The writer 86 has also recognized somewhat doubtfully two Middle Triassic species of this genus Columbites humboldtensis Smith and C. plicatulus Smith. No 

other authentic species of the genus are known.

Columbites consanguineus Smith, n. sp.

Plate 46, Figures 1-13

Shell large, robust, discoidal, widely umbilicate, 

little embracing. Whorls higher than wide, with 

abruptly rounded umbilical shoulders, flattened flanks, 

gently rounded ventral shoulders, and rounded venter. 

Ornamented with rather coarse umbilical ribs that thin 

out on the flanks, curve gently forward and cross the 

venter without interruption. Up to a diameter of 37 

millimeters the sculpture is coarse, and then becomes 

finer, though never obsolete. There are also very fine 

spiral lines visible on the outer shell, as on all American 

species of Columbites. Septa ceratitic, with rounded 

saddles, serrated ventral and lateral lobe, and goniatitic auxiliary. The antisiphonal lobe is flanked by a 

rather long internal lateral.

The height of the last whorl is somewhat less than 

one-third of the diameter of the shell, the width is twothirds of the height; the width of the umbilicus is 

about two-fifths, of the diameter of the shell.

Columbites consanguineus is very closely related to 

C. spencei, differing in its greater lateral compression, 

higher whorl, and somewhat weaker sculpture, also in 

the reduction of the coarse umbilical ribs at a much 

smaller size. It is also related to C. parisianus but is 

much more robust than that species, has stronger 

sculpture through life, and is more narrowly umbilicate. In youth, up to a diameter of about 20 millimeters, the two species are indistinguishable, but from 

then on C. consanguineus diverges rapidly from its 

kinsman, becoming at maturity much more like C. 

spencei.

Horizon and locality: Rare in the Lower Triassic 

Columbites zone of Paris Canyon, 1 mile west of Paris, 

southeastern Idaho; associated with Columbites parisa Smith, J. P., The Middle Triassic marine invertebrate faunas of North America: 

U. S. Oeol. Survey Prof. Paper 83, pp. 36-37, 1914.

sianus, C. spencei, C. ligatus, C. ornatus, Meekoceras 

micromphalus, M. pilatum, M. curticostatum, Pseudosageceras multilobatum, and other forms.

Columbites ligatus Smith, n. sp.

Plate 47, Figures 1-8

Shell evolute, discoidal, little embracing, somewhat 

compressed laterally. Whorls trapezoidal in section, 

with abrupt umbilical shoulders, flattened sides, and 

bluntly rounded ventral shoulders, with broad, nearly 

flat venter. Ornamented with strong umbilical ribs 

that curve forward up the flanks and continue across 

the venter, forming a broad sinus. Parallel with these 

ribs are numerous shallow constrictions that also cross 

the venter. On the outer shell are fine spiral lines, as 

on all members of Columbites. Septa ceratitic, with 

entire saddles and serrated lobes; the ventral lobe is 

divided into two rather short, narrow branches; the 

first lateral is large and strongly serrated; the second 

lateral or auxiliary is small, narrow, and unserrated. 

The internal, antisiphonal lobe is long, narrow, and 

bifid, flanked by a shorter interior lateral. Body 

chamber more than a revolution in length.

In early youth the shell is decidedly gastrioceran in 

shape, ornamentation and septa, having broad trapezoidal section, coarse umbilical knots; strong constrictions, and goniatitic gastrioceran septa.

The height of the last whorl is one-third of the 

diameter of the shell, the width is more than threefourths of the height, the width of the umbilicus is 

slightly less than half the diameter of the shell. These 

dimensions apply only to the mature shell, for in 

youth the whorl is wider than high.

Columbites ligatus is closely related to C. spencei but 

differs in being somewhat more slender and in the 

stronger sculpture, which persists through life. It 

differs in the same way from C. parisianus but to a 

greater degree. It is not closely related to any of the 

Albanian species of this genus, which is known at 

present only in America and in Albania.

In some respects Columbites ligatus shows its gas 

trioceran ancestry more decidedly than 'any other 

species of the group. It also stands out as further 

removed from its near kinsmen with which it is associated.

Horizon and locality: Rare in the Columbites zone 

of the Lower Triassic of southeastern Idaho, at Paris 

Canyon, 1 mile west of Paris; associated with Columbites parisianus, C. spencei, Ophiceras spencei, 0. jacksoni, Pseudharpoceras idahoense, Pseudosageceras multilobatum Noetling, Meekoceras pilatum, M. curticostatum, and other forms.

Columbites minimus Smith, n. sp.

Plate 47, Figures 9, 10

Shell small, evolute, widely umbilicate, with trapezoidal whorls and gently rounded venter. Surface in
CELTITIDAE 107

youth with strong umbilical ribs, and in age with fine 

ribs, folds, and constrictions crossing the venter.

Columbites minimus is evidently a dwarf of the vigorous stock, not merely the young of some unknown 

species; it is certainly not like the young of any known 

species. It shows the beginning of the phenomenon 

of retardation and degeneration, which later will play 

such a significant part in this stock.

.'Horizon and locality: Very rare in the Lower Triassic Columbites zone in Paris Canyon, 1 mile west of 

Paris, Idaho; associated with Columbites parisianus, C. 

spencei, Meekoceras pilatum, Ophiceras spencei, 0. 

jacksoni, Pseudharpoceras idahoense, and other forms.

Columbites ornatus Smith, n. sp.

Plate 46, Figures 14-21

Evolute, discoidal, widely umbilicate, little embracing; whorls low, helmet shaped, somewhat trapezoidal, 

with abrupt umbilical shoulders, rounded flanks, 

broadly rounded ventral shoulders, and arched venter. 

Ornamented with numerous fine umbilical ribs that 

extend, across the flanks, becoming finer on the venter 

but persisting throughout life; also with faint constrictions that become obsolete with age. Surface of the 

shell with fine spiral lines, becoming obsolete at maturity. The young shells are broader and more gastrioceran, but even then the umbilical ribs are never 

coarse. Septa ceratitic, with rounded entire saddles 

and three external lobes, of which the ventral and the 

lateral are strongly serrated and the short auxiliary is 

goniatitic.

The height of the last whorl is less than one-third of 

the diameter of the shell, the width is three-fourths of 

the height, and the width of the umbilicus is less than 

half the diameter of the shell.

Columbites ornatus is most nearly related to C. parisianus, from which it is distinguished by its greater 

slenderness, its much finer and sharper sculpture, and 

the persistence of this sculpture through life. The 

young stages are even more slender and graceful and 

lack the coarse gastrioceran umbilical ribs' of C. 

parisianus and C. spencei.

Horizon and locality: Rare in the Lower Triassic 

Columbites zone of southeastern Idaho, at Paris Canyon, 1 mile west of Paris; associated with Columbites 

parisianus, C. spencei, Ophiceras spencei, 0. jacksoni, 

Meekoceras pilatum, M. curticostatum, Pseudosageceras 

multilobatum, and other forms.

Columbites parisianus Hyatt and Smith

Plate 1, Figures 9-14; Plate 61, Figures 1-21; Plate 72, 

Figures 1-24

1905. Columbites parisiamis. Hyatt and Smith, The Triassic 

cephalopod genera of America: U. S. Geol. Survey 

Prof. Paper 40, p. 51, pi. 1, figs. 9-14; pi. 61, figs. 1-21; 

pi. 72, figs. 1-24.

This species is the type of Columbites Hyatt and 

Smith.

67664 32 S

Form evolute, discoidal, laterally compressed. 

Whorls little embracing and little indented by the 

inner volutions. Cross section high helmet shaped, 

the width being about two-thirds of the height of the 

whorl. The sides are convex, curving without marked 

shoulders to the rounded venter. The indentation is 

shallow, being less than one-fourth of the height of the 

whorl. The outer whorl embraces about three-eighths 

of the inner. The height of the whorl is somewhat 

less than one-third of the entire diameter of the shell.

The umbilicus is broad and shallow, being about 

three-eighths of the entire diameter of the shell.

At maturity the sculpture is weak, consisting of low 

umbilical folds, which extend up the sides and oc^ 

casionally across the venter, being much weaker on 

the ventral portion of the whorl. These folds curve 

sharply forward on the flanks, forming a broad sinus 

on the venter. Parallel with them are numerous 

weak varices, which are distinct on the cast but 

scarcely visible on the outer shell. The surface of the 

shell is ornamented with fine cross striae of growth, 

parallel with the folds, and weaker spiral striae.

The body chamber was seen on several specimens 

to be at least a complete revolution in length, and the 

sculpture persists on the body whorl as well as on the 

chambered portion of the shell.

The septa consist of a ventral lobe divided by a 

deep saddle into two narrow branches, a principal 

lateral lobe in the middle of the flank, and a short, 

narrow auxiliary on the umbilical shoulder. There 

are also a narrow antisiphonal lobe and a single small 

internal lateral. The ventral lobe, the principal 

lateral, and the auxiliary are slightly serrated, and the 

internal lobes are goniatitic. All the saddles are 

rounded and entire.

The foregoing description applies only to the 

mature shell, for up to the diameter of 20 millimeters 

the whorl is low and trapezoidal in cross section, 

sloping outwardly to the angular ventral shoulders, 

where the umbilical ribs end in knots. At this stage 

the sculpture is almost obsolete on the venter, but the 

varices are more strongly marked than at maturity. 

The spiral striae are also very distinct, and the septa 

are all goniatitic. Up to the diameter of 15 millimeters 

the shape, ornamentation, and septa are exactly like 

those of Gastrioceras of the Carboniferous, from which 

genus Columbites appears to have been derived by increasing the involution and height of the whorl and 

by the slight serration of the ventral and lateral lobes. 

This transition is just such as one would expect to 

find in the upper Permian or the lowest Triassic, and 

the beds in which Columbites was found are in the 

Lower Triassic, but that they belong to the Mesozoic 

is shown by the association of Meekoceras, Prionolobus, 

Celtites, and Pseudosageceras, of which the species are 

in part identical with forms from the Meekoceras zone, 

which lies below the Columbites zone.
108 LOWER TRIASSIC AMMONOIDS OF NORTH AMERICA

Columbites parisianus resembles externally Danubites 

strongi Hyatt and Smith but differs from that species 

in its stronger sculpture, especially in the young 

whorls, in its varices, longer body chamber, and in 

lacking a third lateral lobe. The young stages of the 

two genera are so unlike that they must belong to 

different stocks, in spite of their convergence in 

appearance at maturity.

Horizon and locality: Columbites parisianus was 

found by Mr. R. S. Spence in the Lower Triassic 

Columbites zone, 1 mile west of Paris, Bear Lake 

County, southeastern Idaho, associated with Pseudosayeceras multilobatum, Ophiceras jacksoni, Meekoceras 

pilatum, Ophiceras spencei, Celtites ursensis, several 

other species of Columbites, and a few other forms. 

This bed lies above the beds with Meekoceras gracilitatis, which crop out near by, but it still belongs to 

the Lower Triassic and is the probable equivalent of 

the Olenek horizon of northern Siberia.

Columbites spencei Smith

Plate 77, Figures 1-21; Plate 78, Figures 1-16

1914. Columbites spencei. Smith, The Middle Triassic marine 

invertebrate faunas of North America: U. S. Geol. 

Survey Prof. Paper 83, p. 36, pi. 70, figs. 1-16; pi. 

71, figs. 1-16.

Form evolute, discoidal, robust. Whorls helmet 

shaped, slightly higher than wide, embracing half of 

the inner whorl and indented by it to one-sixth of the 

height. Flanks and venter rounded, without ventral 

shoulders at the junction. Umbilical shoulders hardly 

developed, umbilicus wide and shallow, being half the 

diameter of the shell. The surface is ornamented at 

maturity with rather weak lateral ribs that swing 

forward on the venter in a strong sinus and with weak 

constrictions at distant and irregular intervals. There 

are also weak spiral lines on the shell. The body 

chamber is more than a revolution in length. The 

septa are ceratitic, the saddles being entire, the 

ventral lobe divided and slightly serrated, the lateral 

lobe distinctly serrated, and the auxiliary either goniatitic or slightly serrated. Of the inner lobes the antisiphonal is bifid, and it is flanked by a simple lateral.

Up to a diameter of 10 millimeters this species is a 

typical Gastrioceras, having simple gastrioceran lobes, 

trapezoidal cross section, coarse umbilical ribs, and 

strong constrictions. At about 10 millimeters the 

septa become slightly serrated, but the gastrioceran 

form and sculpture persist until a diameter of about 

35 millimeters is reached, when the whorl becomes. 

higher and more compressed laterally. The shoulders 

become obsolete, and the umbilical ribs become weaker 

and extend across the venter. These stages are 

figured on Plates 77 and 78.

Columbites spencei greatly resembles C. parisianus 

Hyatt and Smith 87 but differs from th,at species in the 

more robust form, stronger sculpture, and the persistence of the gastrioceran stage much later in life.

The specific name was given in honor of Mr. R. S. 

Spence, the discoverer of this fauna and a pioneer 

collector of Triassic fossils.

This species should have been the type of Columbites, 

instead of C. parisianus, for it is much more distinctive 

and characteristic, but the material illustrating it was 

obtained after the descriptions and illustrations of 

C. parisianus were completed and ready for publication.

Horizon and locality: Rather common in the Lower 

Triassic Columbites zone, Paris Canyon, a mile west of 

Paris, Idaho; associated with Columbites parisianus, 

Ophiceras spencei, 0. jacksoni, Meekoceras pilatum, 

Pseudosageceras multilobatum, Pseudharpoceras idahoense, and other forms.

Family HALORITIDAE

Subglobose, involute genera, with lateral ribs, commonly crossing the venter, and in some groups with 

spines or knots on the ribs. No keels nor ventral 

furrows are known hi this group, but the interruption 

of the ribs on the venter in some specimens gives the 

appearance of a furrow.

The septa are ammonitic, dolichophyllic, or ceratitic. 

The young of this family resemble the Glyphioceratidae 

and more especially the genus Pericyclus Mojsisovics, 

of the Carboniferous.

This family was formerly classed by Mojsisovics 

under the Tropitidae, but it did not come from the 

main stock, being rather a parallel development from 

the same Carboniferous radicle but probably from 

different branches of the same family.

The Haloritidae are known chiefly from the Upper 

Triassic, in the Karnic and Noric stages, in the Alpine 

Province, the Himalayas, and western America. They 

are represented in America by Leconteiceras Smith, 

Sagenites Mojsisovics, Halorites Mojsisovics, Metasibirites Mojsisovics, Juvavites Mojsisovics, and Gonionotites Gemmellaro, all confined to the Upper Triassic. 

They are sparingly represented in the Lower Triassic 

by Juvenites Smith, Thermalites Smith, and Prenkites 

Arthaber; also in the Middle Triassic by Isculites

Mojsisovics.

Genus JUVENITES Smith

1927. Juvenites. Smith, Upper Triassic marine invertebrate 

faunas of North America: U. S. Geol. Survey Prof. 

Paper 141, p. 23.

Type:. Juvenites kraffti Smith.

s 7 Hyatt, Alpheus, and Smith, J. P., The Triassic cephalopod genera of America: 

U. S. Geol. Survey Prof. Paper 40, p. 51, pi. 1, figs. 9-14; pi. 61, figs. 1-21; pi. 62, 

figs. 1-24, 1905.
HALOBJTIDAE 109

Form robust, moderately involute, widely umbilicate, 

cross sections trapezoidal. Surface with numerous 

close-set periodic constrictions. Body chamber long. 

Septa simple, goniatitic, with divided ventral lobe and 

two simple laterals.

Juvenites includes the primitive Lower Triassic 

forms that have hitherto been classed under the 

arrested and reversionary Nannites Nannites dieneri 

Hyatt and Smith, Nannites medius Krafft, Nannites 

herberti Diener, Nannites? hindostanus Diener.

So far as known, this genus is confined to the Lower 

Triassic of western America and the Indian region, 

in which horizon it is represented by several species. 

It forms a connecting link between Gastrioceras of the 

group of G. ylobulosum and the Ptychitidae and probably also the Haloritidae. It is quite Paleozoic in 

aspect, little removed in characters and in time from 

the ancestral group, still progressive, or at most 

slightly retarded. The true Nannites, of the Middle 

Triassic is decidedly reversionary and can- hardh7 be 

congeneric with the Lower Triassic species.

Juvenites dieneri Hyatt and Smith

Plate 7, Figures 5-25; Plate 32, Figures 1-lC

1905. Nannites dieneri. Hyatt and Smith, The Triassic cephalopod genera of America: U. S. Geol. Survey Prof. 

Paper 40, p. 79, pi. 7, figs. 5-25.

Form subglobose, involute, deeply embracing; whorls 

depressed, helmet shaped, wider than high, indented 

more than half the height by the preceding whorl. 

Breadth of whorl slightly greater than its height, 9:7. 

Umbilicus narrow, deep, one-fifth of the total diameter 

of the shell. Venter broadly rounded. Umbilical 

shoulders abrupt and umbilical slope steep. Body 

chamber long, comprising about the last volution.

Surface nearly smooth in youth but marked with 

varices and constrictions that become more numerous 

as the shell grows older, until there are as many as 10 

to a revolution. Between the principal constrictions 

and varices intervene minor cross ribs, and the entire 

shell is ornamented with fine radial striae, like those 

in the Glyphioceratidae.

Septa goniatitic; external lobe divided by a small 

siphonal notch into two sharp-pointed lobes; lateral 

lobe broader and not so deep; shallow auxiliary on the 

umbilical slope. The two lateral saddles are broadly 

rounded. The internal antisiphonal lobe is narrow 

and short, the lateral is similar, and there is a smaller 

auxiliary inside of the umbilical suture. The internal 

saddles are broadly rounded.

This species is most nearly related to Juvenites? 

hindostanus Diener 88 but differs from the Indian species 

in being broader and having fewer constrictions of the

88 Dionor, Carl, Cephalopoda of the Lower Trias: India Oeol. Survey Mem., 

Palnoonlologifi Indica, 15th ser., Himalayan fossils, vol. 2, pt. 1, p. 68, pi. 7, figs. 3, 

12,1897.

shell. The divisions of the ventral lobe are also somewhat sharper. The constrictions are as distinctly 

marked on the shell as on the cast, whereas on J. 

hindostanus they are visible chiefly on the cast.

These differences would be considered by the writer 

not to have a greater than varietal significance if Diener 

had not used even smaller differences to separate his 

Juvenites herberti from J.? hindostanus. But in small 

shells with few distinctive characters, those marks 

that are seen should be accorded greater significance 

in classification than those on shells with many characters.

This species grew to the diameter of at least 24 

millimeters.

Dimensions of a symmetrical specimen of Juvenites dieneri

Millimeters

Diameter.___________---__-_-_-_-___-- 13. 5

Height of whorl...._-------.-_-_-____-- 7

Height of last whorl from the preceding... 3

Width of last whorl__----_-_----__--_-_ 9

Width of umbilicus--.-___-__-_____._.-_ 2. 75

Involution ____________________________ 4

Horizon and locality: Juvenites dieneri is common 

in the Lower Triassic Meekoceras zone of Union Wash, 

about \% miles east of Union Spring, Inyo Range, east 

side of Owens Valley, about 15 miles southeast of 

Independence, Inyo County, Calif.

Juvenites kraffli Smith

Plate 21, Figures 1-10

1927. Juvenites kraffti. Smith, Upper Triassic marine invertebrate faunas of North America: U. S. Geol. Survey 

Prof. Paper 141, p. 23, pi. 21, figs. 1-10.

Form broad, widely umbilicate, with low crescentic 

cross section. Surface with very numerous closepressed folds, giving an imbricated appearance. Body 

chamber long. Septa simple, goniatitic, with divided 

ventral and two laterals.

Closely related to Juvenites dieneri Hyatt and 

Smith 89 of the Lower Triassic but broader, less involute, more strongly sculptured, and more decidedly 

gastrioceran in appearance. ' Horizon and locality: Lower Triassic Meekoceras 

zone at locality 5, 1 mile east of Hot Springs, north end 

of Bear Lake, southeastern Idaho; also at locality 1, 

5 miles east of Grays Lake; also at locality 3, Wood 

Canyon, Aspen Mountains, 9 miles east of Soda 

Springs. It is confined to the zone of Pseudosageceras 

multilobatum and associated with Meekoceras gracilitatis, M. mushbachanum, Flemingites russelli, Hedenstroemia kossmati, Aspenites acutus, Cordillerites angulatus, Lanceolites compactus, Ussuria-waageni, Xenodiscus intermontanus, Lecanites arnoldi, and other forms.

M Hyatt, Alpheus, and Smith, J. P., The Triassic cephalopod genera of America: 

U. S. Qeol. Survey Prof. Paper 40, p. 79, pi. 7, figs. 5-25,1905.
110 LOWER TBJASSIC AMMONOIDS OF NORTH AMERICA

Juveniles sanctorum Smith, n. sp.

Plate 31, Figures 22-30

Shell small, laterally compressed, with flattened 

sides, and broadly arched venter; narrowly umbilicate, 

involute and deeply impressed by the inner whorl. 

Surface with numerous shallow constrictions, giving a 

strong sculpture to the surface of the shell and the cast.

Septa goniatitic, with small external lobe, longer 

lateral, and small auxiliary on the umbilical border.

Dimensions of the type specimen of Juveniles sanctorum

Millimeters 

Diameter. __----..__------___--______-_ 13. 5

Height of last \vhorl_-_---_____..._______ 6. 0

Height of last whorl from the preceding-- 3. 5 

Width of last whorl___.______________ 6. 0

Width of umbilicus.---_--__-_ .___.._____ 2. 5

Juvenites sanctorum is closely related to "Nannites" 

medius Krafft and Diener, of the Lower Triassic of 

India, differing only in its somewhat stronger sculpture. 

It is also related to J. septentrionalis, from which it 

differs in its greater involution, compression of the 

whorl, and weaker sculpture.

Horizon and locality: Rather rare in the Lower 

Triassic Meekoceras zone of southeastern Idaho, at 

locality 3, head of Wood Canyon, Aspen Mountains, 

9 miles east of Soda Springs; associated with Meekoceras gracilitatis, Flemingites russelli, Hedenstroemia 

kossmati, Aspenites acutus, Cordillerites angulatus, 

Lanceolites compactus, and other forms.

Juvenites septentrionalis Smith, n. sp.

Plate 31, Figures 31-40

Shell small, robust, rather evolute, with broad semiangular whorls and wide umbilicus. Surface with 

very numerous close-set constrictions, showing on 

both shell and cast. Body chamber long, more than a 

revolution. Septa goniatitic, with short, narrow external lobe divided into two branches, a larger lateral, 

small auxiliary on the umbilical shoulder; and a divided 

long, narrow antisiphonal lobe, flanked by a short 

internal lateral.

Juvenites septentrionalis is very similar to "Nannites" hindostanus Diener 90 but differs from the Indian 

species in its slightly wider umbilicus, somewhat more 

compressed whorl, and stronger sculpture.

Krafft 91 makes the statement that delicate denticulations may be seen on the type specimen of "Nannites" hindostanus and on other specimens from the 

same region. This alone would prevent identification

9° Diener, Carl, Cephalopoda of the Lower Trias: India Geol. Survey Mem., 

Palaeontologia Indica, 15th ser., Himalayan fossils, vol. 2, pt. 1, p. 68, pi. 7, figs. 

3a-b, 1897.

91 Kraflt, A. von, and Diener, Carl, Lower Triassic Cephalopoda from Spiti, 

Malla Johar, and Byans: India Geol. Survey Mem., Palaeontologia Indica, 15th 

ser., vol. 6, Mom. 1, p. 141, 1909.

of the American with the Indian species, for on the 

numerous specimens of Juvenites septentrionalis the 

septa are distinctly goniatitic.

Horizon and locality: Rather common in the Lower 

Triassic Meekoceras zone of southeastern Idaho, at 

localities 1, 2, 3, 4, and 5, associated with Meekoceras 

gracilitatis, Flemingites russelli, Cordillerites angulatus, 

Lanceolites compactus, Hedenstroemia kossmati, Aspenites acutus, Pseudosageceras multilobatum, and 

other forms.

Genus PRENKITES Arthaber

1911. Prenkites. Arthaber, Die Trias von Albanien: Beitr.

Palaontologie Oesterr.-Ungarns u. des Orients, Band

24, p. 258. 

1922. Prenkites. Welter, Die Ammoniten der Unteren Trias

von Timor: Palaeontologie von Timor, Lief. 11, Abh.

19, p. 150.

Form evolute, robust, depressed, widely umbilicate, 

little embracing. Whorls low and broad, flanks reduced to little or nothing. Body chamber long.

Septa ceratitic, with rounded entire saddles and 

serrated lobes, of which there are only three visible 

externally, the short ventral, the relatively enormous 

lateral, and a small auxiliary.

Prenkites differs from Isculites in the ceratitic 

instead of slightly ammonitic lobes and in the very 

depressed instead of the highly arched whorl. It 

differs from Thermalites in the greater simplicity of 

the septa and in the more exaggerated gastrioceran 

shape of the whorls.

The type of Prenkites is P. malsorensis Arthaber, 92 

from the Lower Triassic Columbites beds of Albania. 

It is represented in America by a single species, which 

is described below.

Prenkites depressus Smith, n. sp.

Plate 31, Figures 16-18

Form evolute, broadly umbilicate, depressed, broad, 

little embracing, and little indented by the inner 

whorl. Flanks exceedingly narrow, being merely the 

meeting of the abrupt ventral shoulder with the umbilical slope.

Surface nearly smooth, without ribs or constrictions. 

Septa distinctly serrated, with rounded saddles, and 

with a small ventral, very large lateral lobe, and a 

small auxiliary just visible on the umbilical border. 

Body chamber apparently long but uncertain.

Prenkites depressus has some resemblance to Thermalites thermarum but differs in the greater evolution, 

wider umbilicus, weaker sculpture, and flattened 

whorl. It is more nearly related to Prenkites malsorensis Arthaber 93 but differs in the less pronounced

92 Arthaber, G. von, Die Trias von Albanien: Beitr. Palaontologie Oesterr. 

Ungarns u. des Orients, Band 24, p. 258, pi. 22, figs. 17-19,1911. 

as Idem.
HALORITIDAE 111

flattening of the whorl, and entirely in the faunal 

association.

Horizon and locality: Very rare in the Lower 

Triassic Meekoceras zone of southeast Idaho, at locality 3, head of Wood Canyon, Aspen Mountains, 9 

miles east of Soda Springs; associated with Meekoceras gracilitatis, Flemingites russelli, Hedenstroemia 

kossmati, Cordillerites angulatus, Pseudosageceras multilobatum, and other forms.

Genus THERMALITES Smith

1927. Thermaliles. Smith, Upper Triassic marine invertebrate

faunas of North America: U. S. Geol. Survey Prof.

Paper 141, p. 24. 

1.911. Isculiles (part). Arthaber, Die Trias von Albanien:

Beitr. Paliiontologie Oesterr.-Ungarns u. des Orients,

vol. 24, p. 259. 

Not 1893. Isculiles. Mojsisovics, Die Cephalopoden der

Hallstatter Kalke: K.-k. geol. Reichsanstalt Wien

Abh., Band 6, Halfte 2, p. 64.

Type: Thermalites thermarum Smith. 94

Form robust, subspherical, with broad subtrapezoidal whorls, wide umbilicus. Surface with numerous 

constrictions and folds. Body chamber long. Septa 

with entire saddles and slightly serrated lobes of 

simple pattern.

Tins genus is transitional from Juvenites to the 

Haloritidae, differing from the former only in the 

serration of the lobes and from the latter only in the 

rudimentary sculpture and the very primitive septa.

Tliermalites should probably include "Isculites" 

originis Arthaber, 95 which is certainly not a member 

of Isculites and which is closely related to Thermalites 

thermarum.

This genus is confined to the Lower Triassic of 

western America, and, somewhat doubtfully, Albania; 

it is probably ancestral to the true Isculites of the 

Columbites zone of the Lower Triassic and of the 

Middle Triassic.

"Smith, J. P., Upper Triassic marine invertebrate faunas of North America: 

U. S. Cleol. Survey Prof. Paper 141, p. 24,1927. 

«s Arthaber, O. von, op. cit. (Die Trias von Albanien), p. 259, pi. 23, figs. 1-10.

Thermalites thermarum Smith

Plate 21, Figures 11-20

1927. Thermalites thermarum. Smith, Upper Triassic marine 

invertebrate faunas of North America: U. S. Geol. 

Survey Prof. Paper 141, p. 24, pi. 21, figs. 11-20.

Form robust, with highly arched, helmet-shaped, 

deeply embracing whorls. and subtrapezoidal, moderately wide umbilicus. Surface with numerous strong 

 constrictions, which become nearly obsolete with age 

and are replaced by rather weak folds. Septa with 

rounded entire saddles and serrated lobes. The external septa.consist of a divided ventral lobe and two 

laterals; the internal septa consist of a divided antisiphonal and two laterals, all slightly serrated. The 

body chamber is more than one revolution in length. 

The height of the last whorl is nearly half the total 

diameter of the shell, and the width is one and a half 

times the height. The whorl is rather deeply embracing and is indented to half its height by the inner 

whorl. The width of the umbilicus is one-third of the 

diameter of the shell.

Thermalites thermarum differs from "Isculites" 

originis Arthaber in being more trapezoidal and in 

having stronger sculpture. It is almost certainly congeneric with that species, and neither can belong to 

Isculites. It has also a very close resemblance to 

Juvenites kraffti Smith, differing only in the serration 

of the lobes, the form, sculpture, and ground plan of 

the septa being the same in both species. In both 

species the shell is ornamented with very fine cross 

striae of growth and both lack suggestion of spiral 

lines, so common on descendants of the gastrioceran 

stock.

Horizon and locality: Rather common in the Lower 

Triassic Meekoceras zone of Aspen Ridge, Wood Canyon, locality 1, 9 miles east of Soda Springs; and at 

locality 5, 1 mile east of Hot Springs, north end of Bear 

Lake, southeastern Idaho. It was associated with 

Meekoceras gracilitatis, M. mushbachanum, Flemingites russelli, F. aj)lanatus, F. cirratus, Hedenstroemia 

kossmati, Cordillerites angulatus, Lanceolites compactus, 

Ussuria waageni, Aspenites acutus, Pseudosageceras 

multilobatum, and other forms.

PLATES

113
PLATE 1

FIGURES 1-3. Flemingites russelli Hyatt and Smith (p. 53). 

1-3. Side and front views and septum.

 From Lower Triassic Meekoceras zone, 9 miles northeast of Wood Canyon, Aspen Ridge, Idaho. Collection of United

States National Museum.

FIGURES 4-8. Hedenstroemia (Clypites) tennis Hyatt and Smith (p. 79). 

4-6. Side and rear views and septum. 

7, 8. A young specimen of the same species, showing the Ambites stage of growth; diameter 9 millimeters. This species may

prove to be merely the young of Hedenstroemia kossmati Hyatt and Smith. 

From Lower Triassic Meekoceras zone, 9 miles east of Wood Canyon, Aspen Ridge, Idaho. Collection of United

States National Museum. 

FIGURES 9-14. Columbites parisianus Hyatt and Smith (p. 107).

9-11. Left side and front views and septum of type specimen.

12-14. Left side, front, and rear views of an adolescent specimen; diameter 33 millimeters.

From Lower Triassic Columbites zone, 1 mile west of Paris, southeastern Idaho. Collection of United States National 

Museum.

114
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PLATE 2

FIGURES 1-8. Cordilleriles angulalus Hyatt and Smith (p. 96).

1-3. Side and front views and septum.

4, 5. Side and rear view of another specimen.

7, 8. Side view and septum of an adolescent specimen. Sicanites stage; diameter of 7 millimeters.

6. Side view of an adolescent specimen, showing transition from Sicanites to Cordillerites. 

FIGURES 9-13. Aspeniles acutus Hyatt and Smith (p. 86).

9-11. Side and front views and septum of an immature specimen.

12, 13. Left side view and septum of a larger specimen.

All specimens figured in this plate came from Lower Triassic Meekoceras zone, Wood Canyon, 9 miles east of Soda 

Springs, Aspen Ridge, Idaho. Collection of United States National Museum. .

115
PLATE 3

FIGURES 1-5. Aspenites acutus Hyatt and Smith (p. 86). 

1, 2. Side and front views of the type specimen.

3. Side view of a larger specimen, showing the septa.

4. 5. Side and rear views of a young specimen; diameter 4.5 millimeters. 

FIGURES 6-11. Sturia compressa Hyatt and Smith (p. 93). 

6, 7. Side and front view of the type specimen. 

8, 9. Septa drawn from both sides of another specimen. 

10, 11. Side view and septum of a smaller specimen.

All specimens figured in this plate came from Lower Triassic Meekoceras zone, Owenites subzone, Union Wash, Inyo 

Range, Inyo County, Calif. Collection of United States National Museum.

116
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LOWER TRIASSIC AMMONOIDS
PLATE 4

FIGURES 1-3. Pseudosageceras multilobaluin Noetling (p. 87). Side and front views and septum of the type specimen. 

FIGURES 4-10. Lanceolites compactus Hyatt and Smith (p. 90). 

4-6. Side and rear views and septum. 

7. Septum of another specimen. 

S-10. Side and front views and septum of a young specimen; diameter 12 millimeters.

All the specimens of Lanceolites compaclus figured in this plate are immature and have not yet acquired the lanceolate 

type of septa which is characteristic of maturity in this genus. The mature stage is shown in Plate 40, Figures 9-11. 

All specimens figured came from Lower Triassic Meekoceras zone, Wood Canyon, 9 miles east of Soda Springs, 

Aspen Ridge, Idaho. Collection of United States National Museum.

117
PLATE 5

FIGURES 1-6. Pseudosageceras multilobatum Noetling (p. 87). 

1, 2. Side and front views of a large specimen. 

3, 4. Side view and septum of a smaller specimen. 

5, 6. View of ventral keel. 

FIGURES 7-9. Lanceolites compactus Hyatt and Smith (p. 90).

7, 8. Side view and septum considerably modified by weathering.

9. Septum from a small specimen. Details of septum not quite correct and greatly modified by weathering.

The specimens shown in. this plate are immature and have not yet acquired the lanceolate type of septum that characterizes maturity. The mature stage is shown on Plate 40, Figures 9-11. All specimens figured in this plate came 

from Lower Triassic Meekoceras zone, Owenites subzone, Union Wash, Inyo Range, Inyo County, Calif. Collection 

of United States National Museum.

118
U. S. GEOLOGICAL SURVEY PROFESSIONAL PAPER 167 PLATE 5

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12

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LOWER TRIASSIC AMMONOIDS

X 2
PLATE 6

FIGURES 1-16. Inyoites oweni Hyatt and Smith (p. SO).

1. Side view.

2. Septum drawn from a specimen of the same size as Figure 1.

3. 4. Side and front views of a smaller specimen.

5. Septum from a smaller specimen; diameter about 25 millimeters.

6. Side view of small specimen.

7. 8. Front view and septum of a fragment of the whorl.

9-11. Side, front, and rear views of a fragment of whorl of young specimen; diameter about 15 millimeters.

12. Septum, external and internal, from the same specimen.

13. Side view of young specimen.

14-16. Side, front, and rear views and septum of larval specimen; diameter 2.5 millimeters.

From Lower Triassic Meekoceras zone, Oweniles subzone, Union Wash, Inyo Range, Inyo County, Calif. Collection of 

United States National Museum.

119
PLATE 7

FIGURES 1-4. Prosphingites aitsfinrHyatt and Smith (p. 98). Side, front, and rear views and septum of the type specimen. 

FIGURES 5-25. Juveniles dieneri Hyatt and Smith (p. 109).

5, 6. Side and rear views.

7-9. Side and front views and septum.

10-13. Side, front, and rear views and septum of the type specimen.

14. Inside view of part of the body chamber broken from the specimen shown in Figures 10-13.

15-18. Side, front, and rear views and septum of an adolescent specimen; diameter 9.5 millimeters.

19-21. Side, front, and rear views of an adolescent specimen, showing the shell.

22-25. Side, front, and rear views and septum of a larval specimen having a diameter of 2.6 millimeters. 

FIGURES 26-33. Xenodiscus marcoui Hyatt and Smith (p. 47).

26. Side view.

27. 28. Side view and cross section of a broken whorl.

29-31. Side view, cross section, and septum.

32, 33. Side and front views of an adolescent specimen.

All specimens figured in this plate came from Lower Triassic Meekoceras zone, Owenites subzone, Union Wash, Inyo 

' Range, Inyo County, Calif. Collection of United States National Museum.

120
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X 2

11

12

I

13

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19

X 7

25 26

LOWER TRIASSIC AMMONOIDS

X 7 X 7

27

 *7 28 29
PLATE 8

FIGURES 1-1.5. Paranannites aspenensis Hyatt and Smith (p. 98).

1-3. Side and rear views and septum of a specimen of which the outline has been partly restored, as shown in the shading.

4-6. Side, front, and rear views.

7. Septum of the same specimen.

S-10. Side, front, and rear view of an adolescent specimen.

11. Septum from specimen shown in Figures 8-10.

12. 13. Side and rear views of an adolescent specimen; diameter 6 millimeters.

14, 15. Side and rear views of a specimen showing the transition from Aganides to Nannites; diameter 4 millimeters. 

FJGUKES 16-29. Ophiceras dieneri Hyatt and Smith (p. 48).

16-18. Side and front views and septum of the type specimen. 

19, 20. Side and front views of a smaller specimen.

21. Side view of an adolescent specimen.

22. 23. Side and rear views of a specimen; diameter 5.5 millimeters.

24. Septum of the same specimen.

25-27. Side, front, and rear views of young specimen; diameter 3.5 millimeters.

28, 29. Side and rear views of larval specimen; diameter 2.5 millimeters.

All specimens figured in this plate came from Lower Triassic Meekoceras zone, Wood Canyon, 9 miles east of Soda 

Springs, Aspen Ridge, Idaho. Collection of United States National Museum.

121
PLATE 9 .

FIGURES 1-3. Anasibirites noetlingi Hyatt and Smith (p. 74). Side, front, and rear view's. 

FIGURES 4-10. Danubites strongi Hyatt and Smith (p. 85).

4-6. Side and front views and septum of the type specimen.

7, 8. Side and end views of a fragment of the body, chamber, showing the normal shape of the cross section. '.

9,10. Side and front views of a smaller specimen. ' ' . . ' ' 

FIGURES 11-16. Lecanites knechti Hyatt and Smith (p. 41).

11-13. Side and front views and septum of the type specimen.

14-16. Side and front views and septum of a smaller specimen.

All specimens figured in this plate came from Lower Triassic Meekoceras zone, Owenites subzone, Union Wash,_Inyo 

Range, Inyo County, Calif. Collection of United States National Museum.

122
U. S. GEOLOGICAL SURVEY PROFESSIONAL PAPER 167 PLATE 9

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16

LOWER TRIASSIC AMMONOIDS

X6
TJ. S. GEOLOGICAL SURVEY PROFESSIONAL PAPER 167 PLATE 10

X2

10

^^

11 12 13

X 2

18

X 2

^ ^

14

15 16

X4 t

17

23d *t32 21 20 19 xie

LOWER TRIASSIC AMMONOIDS
PLATE 10

FIGURES 1-23. Owenites koeneni Hyatt and Smith (p. 100).

I-4. Side, front, and rear views and septum of the type specimen.

5, 6. Side and front views of a specimen showing only the body chamber in the last volution.

7-10. Side, front, and rear views and septum of adolescent specimen, showing the transition from goniatite to ceratitic stage; 

diameter 15 millimeters.

II-13. Side, front, and rear views of an adolescent specimen, showing only the goniatite stage; diameter 9 millimeters.

14. Septum from the same specimen.

15-17. Side, front, and rear views of small adolescent specimen; diameter 5 millimeters.

18, 19. Left side and septum of larval specimen, showing Nannites stage; diameter 2.4 millimeters.

20-23. Side, front, and rear views and septum of larval shell showing the Nannites stage; diameter 1.9 millimeters.

All specimens figured in this plate came from Lower Triassic Meekoceras zone, Owenites subzone, Union Wash, Inyo 

Range, Inyo County, Calif. Collection of United States National Museum.

123
PLATE 11

FIGURES 1-14. Flemingites aplanatus White (p. 52).

1-3. Side and front views and septum of White's type specimen. (U. S. Geol. and Geog. Survey Terr. Twelfth Ann. Kept., 

pt. 1, pi. 31, figs, la, Ib, and Id, 1880.)

4-7. Side, front, and rear views and septum of an adult specimen.

8-10. Side and front views and septum of a fragment of the chambered shell.

11, 12. Side view and septum of an adolescent specimen, showing the Lecanites stage.

13, 14. Side and cross section.

From Lower Triassic Meekoceras zone, southeastern Idaho. Specimen shown in Figures 1-3 from locality 2 of White, 

50 miles north of the Utah line and 'about 18 miles west of the Wyoming line; specimen shown in Figures 4-14 from 

Wood Canyon, 9 miles east of Soda Springs, Aspen Mountains, Idaho. Collection of United States National 

Museum. .

124
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10

11

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LOWER TRIASSIC AMMONOIDS
PLATE 12

FIGURES 1-13. Meekoceras gracilitatis White (p. 57).

1. Side view of White's type specimen. (Copied from pi. 31, fig. 2a, of White, U. S. Geol. and Geog. Survey Terr. Twelfth 

Ann. Rept., pt. 1.)

2. 3. Side and front views of a smaller specimen. (Copied from White's pi. 31, figs. 2b, 2c.)

4. Septum of a larger specimen. (Copied from White's pi. 31, fig. 2d.)

5. 6. Side view and septum of a large specimen.

7-10. Side, front, and rear views and septum of a smaller specimen.

11-13. Side, front, and rear.

From Lower Triassic Meekoceras zone, southeastern Idaho. Specimens shown in Figures 1-4 from locality 1 of White, 

65 miles north of the Utah line and 18 miles west of Wyoming; specimens shown in Figures 5-13 from Wood Canyon, 

9 miles east of Soda Springs, Aspen Ridge, Idaho. Collection of United States National Museum.

125
PLATE 13

FIGTJKES 1-18. Meekoceras gracilitatis White (p. 57).

1. Broken specimen showing cross section of the whorls (locality 1 of White). 

2-4. Side and front views and septum; diameter 14.5 millimeters.

5. Side view of the adolescent specimen, showing the end of the goniatite stage; diameter 12 millimeters.

6. 7. Side and front views; diameter 5.5 millimeters.

8, 9. Side and front views; diameter 4.5 millimeters.

10-12. Side, front, and rear views; diameter 2.56 millimeters.

13-15. Side, front, and rear views of larval specimens; diameter 1.32 millimeters.

16-18. Front and top views; protoconch with two chambers attached; diameter 0.6 millimeter.

From Lower Triassic Meekoceras zone, Wood Canyon, 9 miles east of Soda Springs, Aspen Ridge, Idaho. Collection

of United States National Museum. 

126
tT. S. GEOLOGICAL SURVEY PROFESSIONAL PAPER 167 PLATE 13

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X 20

14

X 20 X 2tt

15

10

16

67664 32 10

X30

17 18

LOWER THIASSIC AMMONOIDS
TJ. S. GEOLOGICAL SURVEY PBOFESSIONAL PAPER 167 PLATE 14

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LOWER TRIASSIC AMMONOIDS
PLATE 14

FIGTJKES 1-8. Meekoceras gracililatis White (p. 57).

1-3. Side and rear views and septum of a broken specimen, showing cross section of the younger whorls. 

4, 5. Side and front views of a smaller specimen.

6. Side view of a large specimen, showing the increasing evolution of the old whorl.

7. S. Side and front views of an adolescent specimen.

From Lower Triassic Meekoceras zone, Owenites subzone, Union Wash, Inyo Mountains, Inyo County, Calif. Collection of United States National Museum.

127
PLATE 15

FIGURES 1-9. Meekoceras (Koninckites) mushbachanum White (p. 61).

1-3. Side and front views and cross section of White's type specimen, after his Plate 31, Figures la, Ib, Ic.

4. Septum from a larger specimen, after White's Plate 31, Figure Id. ' . 5-7. Side and rear views and septum of a smaller specimen.' ''",..

8, 9. Side view and septum of an adolescent specimen. ' ' '

From Lower Triassic Mee'koceras zone, Aspen Ridge, Idaho. Specimens shown, in Figures 1-4 from locality 1 of 

White, 65 miles north .of the Utah line and 18 miles west of the Wyoming line;.specimens shown in Figures 5-9 

from Wood Canyon, 9 rriiles east of Soda Springs. Collection of United States National Museum.'

128
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LOWER THIASSIC AMMONOIDS
PLATE 16

FIGURES 1-3. Meekoceras (Koninckites) tmishbachanum White (p. 61). Side views and septum of a large specimen, showing the

characteristic septum and shape of the whorl.

From Lower Triassic Meekoceras zone, southeastern Idaho, locality 1 of White, 65 miles north of the Utah line and 

IS miles west of the Wyoming line. Collection of United States National Museum.

129
PLATE 17

FIGURES 1-12. Clypeoceras hooveri Hyatt and Smith (p. 63).

1-3. Side and rear views and septum of the type specimen. (Fig. 3, septum not correct in detail.) 

4-6. Side and front views and septum of an adolescent specimen. . 

7, 8. Side and front views of a small specimen showing the Meekoceras stage. 

 9. Septum of the same specimen.

10-12. Side and front views and septum of an adolescent specimen, showing the Lecanites stage, broken out of a larger 

specimen. From Lower Triassic Meekoceras zone, Owenites subzone, Union Wash, Inyo Range, Inyo_County, Calif. 

Collection of United States National Museum.

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LOWER TRIASSIC AMMONOIDS
PLATE 18

FIQTJHES 1-7. Meekoceras (Koninckites) mushbachanum White (p. 61). 

1, 2. Side view and septum of a large specimen. 

3-5. Side and rear views and septum of a smaller specimen. 

6, 7. Side and front views of an immature specimen.

From Lower Triassic Meekoceras zone, Owenites subzone, Union Wash, Inyo Range, Inyo County, Calif. Collection 

of United States National Museum.

131
PLATE 19

FIGURES 1-7. Proptychites walcotti Hyatt and Smith (p. 102). ; 

1-3. Side and front views and septum of the type specimen.

4-6. Side and front views and septum of a small specimen (broken out of the shell shown in fig. 7); diameter 10 millimeters. 

7. Side view of a large shell out of which was broken the small specimen shown in Figures 4-6.

From Lower Triassic Meekoceras zone, Owenites subzone, Union Wash, Inyo Range, Inyo County, Calif. Collection of

United States National Museum. 

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LOWER TR1ASSIC AMMONOIDS
PLATE 20

Flemingites cirratus (White) (p. 53). Side view.

Lower Triassic Meekoceras zone, Rohner's ranch, 1 mile west of Paris, Idaho. Collection of United States Geological 

Survey.

133
PLATE 21

FIGURES 1-10. Juveniles kraffti Smith (p. 109).

I-3. Type.

4-6. Same specimen with, half of the whorl removed. 

7. Old-age form, showing sculpture and septum. 

8-10. Adolescent stage; diameter 5 millimeters. 

FIGURES 11-20. Thermalites thermarum Smith (p. 111).

II-14. Type.

15. Septum of another specimen.

16-18. Adult specimen, showing typical sculpture.

19, 20. Early mature stage; diameter 10 millimeters. . . 

FIGURES 21-23. Lanceolites compactus Hyatt and Smith (p. 90). Adolescent.stage'; diameter 8'millimeters. 

FIGURES'24-40. Ussuria waageni Hyatt and Smith (p. 92).

24-26. Larval stage, corresponding to Manlicoceras; diameter 1.8 millimeters.

27-29. Larval stage, transitional from Manticoceras to Dimorphoceras; diameter 4.4 millimeters.

30-33. Early adolescent stage, transitional from Dimorphoceras to Thalassoceras; diameter 6.5 millimeters.

34-36. Adolescent stage, diameter 12 millimeters; resembling Thalassoceras.

37, 38. Early mature stage, showing beginning of adventitious lobes.

39, 40. Early mature stage, showing adventitious lobes.

All specimens figured in this plate came from the Lower Triassic Meekoceras zone of southeastern Idaho. Collection

of United States Geological Survey. 

134
U. S. GEOLOGICAL SURVEY PROFESSIONAL PAPEK 167 PLATE 21

X 2

LOWER TRIASSIC AMMONOIDS
U. S. GEOLOGICAL SURVEY PROFESSIONAL PAPER 167 PLATE 22

I

\

X3

10

X2C2 X 2/2

16

17 xto

12 * s fP r;"<

13

20 23 X 15

18

LOWER TRIASSIC AMMONOIDS
. PLATE 22

FIGURES 1-23. Flemingites aplanafots White (p. 51). 

1, 2. Adult specimen, side and front views.

3. Septum of the same specimen.

4. Early mature stage, side view.

5. Septum of the same specimen.

6. Early mature stage, diameter 34 millimeters.

7. Septum of the same specimen.

S, 9. Late adolescent stage, diameter 27 millimeters, transitional from Xenodiscus to Flemingites.

10. Septum of the same specimen.

11. Larval stage at diameter 6 millimeters corresponding to Lecanites, included in broken specimen of diameter 13 millimeters 

corresponding to Xenodiscus.

12. Septum of the same specimen at diameter 12 millimeters.

13. Septum of the same specimen at diameter 5 millimeters.

14. 15. Larval stage, diameter 10 millimeters, corresponding to Xenodiscus, showing transition from Lecanites at 7 millimeters diameter.

16. Septum of the same specimen, Xenodiscus stage, diameter 10 millimeters.

17. Septum of the same specimen, Lecanites stage, diameter 6 millimeters.

IS, 19. Larval stage, diameter 7 millimeters, corresponding to Lecanites, showing transition from Prolecanites.

20. Septum of the same specimen.

21. 22. Early larval stage, diameter 3 millimeters, transitional from Gephyroceras to Prolecanites.

23. Septum of the same specimen.

The original of Figure 1 came from locality 3, Wood Canyon, 9 miles east of Soda Springs, Idaho; the originals of 

Figures 4 and 8 from locality 2, head of Slug Creek, 14 miles east of Hot Springs, Idaho; the original of Figure 6 

from locality 1, 1 mile east of Grays Lake, Idaho; the originals of Figures 11, 14, 18, and 21 from locality 1, 5 miles 

east of Grays Lake. They were collected from the Lower Triassic Meekoceras zone by J. P. Smith and are in the 

collection of the United States Geological Survey. .

135
PLATE 23 '

FIGURES 1-5. Flemingites russelli Hyatt and Smith var. gracilis Smith (p. 53). 

1, 2. Type.

3. Septum of the same specimen.

4. 5. Adolescent specimen.

FIGURES 6-11. Flemingites aspenensis Smith, n. sp. (p. 52). 

6, 7. Type.

8. Septum of the type.

9. 10. Adolescent stage, transitional from Lecanites to Xenodiscus, diameter 13 millimeters.

11. Septum of the same specimen. 

FIGURES 12-17. Xenodiscus waageni Hyatt and Smith (p. 46).

12. 13. Type.

14. Septum of the same specimen. 

15. 16. Larval stage, diameter 4 millimeters, corresponding to Prolecanites.

17. Septum of the same specimen. 

FIGURES 18-26. Flemingites bannockensis Smith (p. 52).

18. 19. Type.

20. Septum of the type.

21. 22. Adolescent specimen, Xenodiscus stage, diameter 21 millimeters.

23. Septum of the same specimen.

24. 25. Larval stage, corresponding to Lecanites, diameter 12 millimeters. 

26. Septum of the same specimen.

The originals of Figures 1, 4, 18, 21, and 24 came from locality 2, head of Slug Creek, Aspen Mountains, 14 miles 

. east of Soda Springs, Idaho; the originals of Figures 6, 9,' 12, and 15 from locality 1, 5 miles southeast of Grays 

Lake, southeastern Idaho. They were collected from the Lower Triassic Meekoceras zone by J. P. Smith and are in 

the collection of the United States Geological Survey.

136
IT. S. GEOLOGICAL SURVEY PROFESSIONAL PAPER 167 PLATE 23

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10

20

15 16

14

17 xio

12 13

x t'/i

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23

24

26

LOWER TRIASSIC AMMONOIDS
U. 8. GEOLOGICAL SURVEY PROFESSIONAL PAPER 167 PLATE 24

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18

I

19

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17 X 2

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LOWER TRIASSIC AMMONOIDS

29
PLATE 24

FIGURES 1-9. Xenodiscus gilberli Smith, n. sp. (p. 43). 

1, 2. Type.

3. Septum of the type.

4. Late larval stage, corresponding to Lecanites, diameter 10 millimeters.

5. Septum of the same specimen.

6. 7. Late larval stage.

S. Septum of the same specimen at diameter 12 millimeters.

9. Septum of the inner whorl of the same specimen, showing Prolecanites stage. 

FIGURES 10-20. Xenodiscus intermontanus Smith, n. sp. (p. 44).

10. 11. Type.

12. Paratype. Side view.

13. Septum of paratype.

14. 15. Early mature stage.

16. Septum of the same specimen.

17. Septum of an older part of the same specimen.

18. 19. Larval stage, diameter 4 millimeters, corresponding to Prolecanites.

20. Septum of the same specimen. 

FIGURES 21-29. Xenodiscus cordillerahus Smith, n. sp. (p. 43).

21. 22. Type.

23. Septum of the type.

24. 25. Adolescent specimen, beginning of Xenodiscus stage.

26. Septum of the same specimen.

27. 28. Late larval stage, diameter 19 millimeters, corresponding to Lecanites. 

29. Septum of the same specimen.

The original of Figures 1, 4, 6, 12, 14, 18, 21 came from the Lower Triassic Meekoceras zone, locality 3, Wood Canyon, 

Aspen Mountains, 9 miles east of Soda Springs, southeastern Idaho; the original of Figure 10 from the same horizon, 

locality 2, head of Slug Creek, Aspen Mountains, 14 miles east of Soda Springs; the originals of Figures 24 and 27 

from the same horizon, locality 1, 5 miles southeast of Grays Lake, southeastern Idaho. They were collected by 

J. P. Smith and are in the collection of the United States Geological Survey.

137
PLATE 25

FIGURES 1-3. Xenodiscus toulai Smith, n. sp. (p. 45).

1,2. Type. " . .

3. Septum of the type. 

FIGURES 4-6. Xenodiscus tarpeyi Smith, n. sp. (p. 45).

4. 5. Type.

6. Septum of the type. 

FIGURES 7-11. Pseudosageceras multilobatum Noetling (p. 87).

7. 8. Mature specimen.

9. 'Septum of the same specimen.

10. 11. Larval stage, diameter 12.5 millimeters, showing transition from Beloceras-like stage toward Pseudosageceras:

12. Septum of the same specimen at diameter 9 millimeters, showing beginning of Pseudosageceras stage.

13. Septum of the same specimen, diameter 8.5 millimeters.

14. Septum of the same specimen, diameter 5.5 millimeters, showing resemblance to Beloceras.

15. Adolescent stage, diameter 38 millimeters, natural size.

16. Septum of the same specimen (X 2).

FIGURE 17. Xenodiscus whiteanus Waagen (p. 46). Type figure. (Copied from White, C. A., U. S..Geol. and Geog. Survey Terr. 

Twelfth Ann. Rept., pt. l,pl. 31, fig. Ic [= "Meekoceras aplanatum White," part], locality 2, Slug Creek, southeastern 

Idaho.)

The originals of Figures 1, 4, and 10 came from the Meekoceras zone, at locality 3, Wood Canyon, Aspen 

Mountains, 9 miles east of Soda Springs, Idaho; the originals of Figures 7, 15, and 17 from the same horizon, at 

locality 2, Slug Creek, Aspen Mountains, 14 miles east of Soda Springs; they were collected by J. P. Smith and 

are in the collection of the United States Geological Survey. 

138
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PROFESSIONAL PAPEK 167 PLATE 25

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LOWER TRIASSIC AMMONOIDS 16

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IT. S. GEOLOGICAL SURVEY PROFESSIONAL PAPER 167 PLATE 26

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LOWER TRIASSIC AMMONOIDS

21 22
PLATE 26

FIGURES 1-13. Flemingites cirratus (White) (p. 53).

1. Left side.

2. 3, 4. Left and front views and septum.

5, 6. Adolescent specimen, diameter 10.5 millimeters, left and front views.

7. Septum of the same specimen.

8. Septum of the same specimen at diameter 6 millimeters, showing Lecanites stage.

9. Larval stage, diameter 5 millimeters.

10. Septum of the same specimen at diameter 2.5 millimeters, Paralecanites stage.

11. 12. Early larval stage, diameter 1.5 millimeters, Gephyroceras stage.

13. Septum of the same specimen. 

FIGURES 14-23. Flemingites russelli Hyatt and Smith (p. 53).

14. Adolescent stage, diameter 28 millimeters, showing Flemingites stage. With inner coil exposed, showing Lecanites 

stage, at diameter 7 millimeters.

15. Septum of the same specimen, Flemingites stage.

16. Septum of the same specimen at diameter 7 millimeters, Lecanites stage.

17. 18. Xenodiscus stage, diameter 11 millimeters, right side and front.

19. Septum of the same specimen.

20. Septum of the same specimen at diameter 6 millimeters, showing Lecanites stage.

21. 22. Larval stage, diameter 4J^ millimeters, showing Prolecanites stage. 

23. Septum of the same specimen.

From Lower Triassic Meekoceras zone, southeastern Idaho. The originals of Figures 1, 5, 9, 11, 14, and 17 came 

from locality 5, 1 mile east of Hot Spring, Bear Lake County, Idaho; the originals of Figures 2 and 21 from locality 

9 of White, 5 miles east of ,Grays Lake and \y> miles west of Williamsburg, Bannock County, Idaho. They were 

collected by J. P. Smith and are in the collection of the United States Geological Survey.

139
PLATE 27

FIGURES 1-7. Clypeoceras muthianum (Krafft) (p. 64).

1. Adult stage.

2. Septum of the same specimen.

3. 4. Early adult stage.

5. Septum of the same specimen.

6. Adolescent stage, diameter 20 millimeters.

7. Septum of the same specimen. 

FIGURES 8-12. Ussuria occidentalis Smith, n. sp.' (p. 91).

8. 9. Type.

10. Septum of the type.

11. Adolescent specimen, diameter 25 millimeters.

12. Septum of the same specimen. 

FIGURES 13-18. Hedenstroemia hyatti Smith, n. sp. (p. 78).

13. 14. Type.

15. Septum of the type.

16. 17. Adolescent specimen, diameter 20 millimeters. 

18. Septum of same specimen. .

The originals of Figures 1, 3, 6, 8,. and 11 came from the Lower Triassic Meekoceras zone, locality 3, 9 miles east of 

Soda Springs, Aspen Mountains, southeastern Idaho; the original of Figure 13 from the same horizon, at locality 1, 

5 miles southeast of Grays Lake, southeastern Idaho; the original of Figure 16 from the same horizon, at locality 2, 

Slug Creek, Aspen Mountains, 14 miles east of Soda Springs. They were collected by J. P. Smith and are in the 

collection of the United States Geological Survey. 

140
U. S. GEOLOGICAL SURVEY PROFESSIONAL PAPER 167 PLATE 27

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LOWER TRIASSIC AMMONOIDS

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U. S. GEOLOGICAL SURVEY PROFESSIONAL PAPER 167 PLATE 28

32 31

LOWER TRIASSIC AMMONOIDS
PLATE 28

FIGURES 1-7. Lecanites knechti Hyatt and Smith (p. 41). 

1, 2. Adult specimen.

3. Septum of the same specimen.

4. Septum of a smaller specimen.

5. 6. Larval stage, diameter 7 millimeters.

7. Septum of the same specimen. 

FiGuriBS 8, 9. Lecanites arnoldi Hyatt and Smith (p. 41).

8. 9. Larval stage, diameter 1.75 millimeters, corresponding to Prolecaniles.

10. Septum of the same specimen. 

FIGURE 11-16. Hedenstroemia kossmati Hyatt and Smith (p. 78).

11. 12. Late larval stage, diameter 7.5 millimeters.

13. Inner coil of the same specimen.

14. Same specimen, septum at diameter 7 millimeters.

15. Broken coil of the same specimen at diameter 4 millimeters.

16. Septum of the same specimen. 

FIGURES 17-20. Lanceolites compactus Hyatt and Smith (p. 90).

17-19. Larval stage, diameter 5.5 millimeters; shell and septum.

20. Septum of larval stage, diameter 4.5 millimeters. 

FIGURES 21-27. Meekoceras patelliforme Smith, n. sp. (p. 58).

21. 22. Type,

23. Septum of the type.

24. Early mature stage.

25. Septum of the same specimen.

26. 27. Early mature stage, showing faint sculpture. 

FIGURES 28-33. Aspenites laevis Welter (p. 86). 

28, 29. Adult specimen.

30. Septum of the same specimen.

31. 32. Adolescent stage, diameter 17 millimeters.

33. Septum of the same specimen.

All specimens figured in this plate came from the Lower Triassic Meekoceras zone of southeastern Idaho. The originals of Figures 1, 8, 21, 24, 26, and 31 came from locality 3, Wood Canyon, Aspen Mountains, 9 miles east of Soda 

Springs; the originals of Figures 4 and 5 from locality 2, Slug Creek; the originals of Figures 11, 17, and 28 from 

locality 1, 5 miles east of Grays Lake. Collection of United States Geological Survey.

141
PLATE 29

FIGURES 1-8. Dagnoceras haydeni Smith, n. sp. (p. 66).

1-3. Type.

4, 5. Adolescent stage, diameter 14 millimeters.

6-8. Inside whorl of the same specimen, with one-third of a revolution removed. Shell, diameter 11.5 millimeters, and.

septum. 

FIGURES 9-23. Dagnoceras bonnevillense Smith, n. sp. (p. 65).

9-11. Type.

12-14. Adult shell.

15-17. Transitional from larval to adolescent stage, diameter 11 millimeters; showing beginning of serration of septum, at 

diameter 7 millimeters.

18-20. Larval stage, diameter 5.5 millimeters, corresponding to Lecanites.

21-23. Larval stage, diameter 3 millimeters, transitional from Prolecanites to Lecanites. 

FIGURES 24-37. Dagnoceras pealei Smith, n. sp. (p. 66).

24-26. Type.

27, 28. Perfect specimen, with shell preserved.

29-31. Transitional from larval to adolescent stage, diameter 12 millimeters.

32-34. Larval stage, diameter 6 millimeters.

35-37. Larval stage, diameter 1.5 millimeters.

The originals of all figures on this plate came from the Lower Triassic Meekoceras zone of southeastern Idaho, collected by J. P. Smith; collection of United States Geological Survey; the originals of Figures 1, 4, 24, 27, 29, and 

32 from locality 5, 1 mile east of Hot .Spring, north end of Bear Lake; the originals of Figures 12, 15, 18, 21, 

and 35 from locality 1, 5 miles east of Grays Lake; the original of Figure 9 from locality 3, Wood Canyon, Aspen 

Mountains, 9 miles east of Soda Springs.

142
U. S. GEOLOGICAL SURVEY PROFESSIONAL PAPER 167 PLATE 29

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32

67664 32 12

33 34 

LOWER TRIASSIC AMMONOIDS

f

37 36 x '° 35 :
U. 8. GEOLOGICAL SURVEY PROFESSIONAL PAPER 167 PLATE 30

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11 12

3 X 2

21 22 x 10

19

23

26

20 X24 

LOWER TRIASSIC AMMONOIDS

25 24 X 20
PLATE 30

FIGURES 1-26. Aspeniles acutus Hyatt and Smith (p. 86).

I-3. Adult specimen. 

4, 5. Adult specimen. 

6, 7. Adolescent stage, diameter 11 millimeters.

8. Septum of another specimen, at diameter 10 millimeters.

9. 10. Shell at diameter 8.5 millimeters, and septum.

II-13. Shell at diameter 5.5 millimeters; septum at diameter 6.5 millimeters.

14. Septum at 5 millimeters.

15-18. Larval stage, diameter 4 millimeters.

19. Septum at diameter 2.75 millimeters.

20. Septum at diameter 2 millimeters.

21-23. Larval stage, diameter 1.5 millimeters.

24-26. Larval stage, diameter 0.85 millimeter.

The originals of all figures on this plate were collected by J. P. Smith in the Meekoceras zone, Lower Triassic, southeastern Idaho, and are in the collection of the United States Geological Survey. The originals of Figures 1, 4, and 

20 came from locality 5, 1 mile east of Hot Spring; the originals of Figures 6, 8, 11, 21, and 24 from locality 1, 5 

miles east of Grays Lake; the originals of Figures 9, 14, and 19 from locality 3, Wood Canyon, 9 miles east of 

Soda Springs.

143
PLATE 31

FIGURES 1-7. Dagnoceras bridgesi Smith, n. sp. (p. 65). 

1-3. Type.

4-7. Larval stage, diameter 3 millimeters. . 

FIGURES 8-10. Aspenites obtusus Smith, n. sp. (p. 86). Type. 

FIGURES 11, 12. Anasibirites (Goniodiscus) typus Waagen (p. 76). 

FIGURES 13-15. Paranannites pertenuis Smith, n. sp. (p. 99). Type. 

FIGURES 16-18. Prenkites depressus Smith, n. sp. (p. 110). Type. 

FIGURES 19-21. Paranannites compressus Smith, n. sp. (p. 99). Type. 

FIGURES 22-27. Juveniles sanctorum Smith, n. sp. (p. 110). 

22-24. Type.

25-27. Adolescent stage, diameter 6.5 millimeters. 

28-30. Larval stage, diameter 5 millimeters. 

F/GURES 31-40. Juveniles seplentrionalis Smith, n. sp. (p. 110). 

31-33. Type.

34. Septum, outside and inside, of an adult specimen. 

35-37. Larval stage, diameter 4 millimeters. 

38-40. Adolescent stage, diameter 8 millimeters.

The originals of all figures in this plate were collected by J. P. Smith in the Lower Triassic Meekoceras zone of southeastern Idaho;.the originals of Figures 1, 31, 34, and 35 came from locality 2, Slug Creek, Aspen Mountains; the 

originals of Figures 4 and 13, from locality 3, Wood Canyon, Aspen Mountains;.the originals of Figures 8, 16, 

19, 22, 25, 28, and 38, from locality 5, 1 mile east of Hot Spring; the original of Figure 11 from locality 4/Rohner's 

ranch, 1 mile west of Paris. They are in the collection of the United States Geological Survey.

144
IT. S. GEOLOGICAL SURVEY PROFESSIONAL PAPER 167 PLATE 31

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25

i

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26

31 32

13 16

14

vV

22

24

27

28 29

17

y i'/«

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Xl/2

33

35 " 36

x 5

37

. X 3

34 40 

LOWER TRIASSIC AMMONOIDS

38 39
TT. 8. GEOLOGICAL SURVEY PROFESSIONAL PAPER 167 PLATE 32

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t it

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22

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17

30

10 x 10

18

29 ^ 

LOWER TRIASSIC AMMONOIDS

11 12

14

13 xz

X 2

23 24

25

II

32
PLATE 32

FIGURES 1-1.0. Juveniles dieneri Hyatt and Smith (p. 109).

I-3. Adult specimen. 

4-6. Adolescent stage.

7-10. Transition from larval to adolescent stage, diameter 2.5 millimeters. 

FIGURES 11-25. Paranannites columbianus Smith, n. sp. (p. 99).

II-13. Type.

14. Septum of another specimen, showing the inner lobes.

15. Early mature stage, showing the outer shell.

16-18. Earl}' mature stage, diameter 13 millimeters.

19. Same specimen, broken across the center, diameter 6.5 millimeters, showing the inner whorl, larval stage.

20-22. Larval stage, diameter 4.5 millimeters.

23-25. Larval stage, diameter 3.5 millimeters. 

FIGURES 26-30. Meekoceras arLliaberi Smith, n. sp. (p. 56).

26-28. Type.

29, 30. Adolescent stage, diameter 9.5 millimeters, showing goniatite stage of development.

31-33. Larval stage, diameter 2.5 millimeters.

The originals of all figures in this plate were collected by J. P. Smith in the Lower Triassic Meekoceras zone of southeastern Idaho and are in the collection of the United States Geological Survey. The originals of Figures 1, 4, 7, 14, 16, 23, 

26, 29, and 31 came from locality 5, 1 mile east of Hot Spring; the originals of Figures 11 and 20 from locality 3, 

Wood Canyon, Aspen Mountains.

145
PLATE 33

FIGURES 1-14. Meekoceras sylvanum Smith, n. sp. (p. 59). 

1-3. Type.

4. Septum, outer and inner, of another specimen.

5. Early mature stage.

7-9. Adolescent stage, diameter 17 millimeters.

10, 11. Adolescent stage, diameter 12 millimeters.

12-14. Adolescent stage, diameter 10 millimeters. 

FIGUKES 15-20. Meekoceras cristatum Smith, n. sp. (p. 56).

15-17. Adult shell.

18-20. Larval stage, diameter 3 millimeters.

The originals of all figures in this plate were collected by J. P. Smith in the Lower Triassic Meekoceras zone of southeastern Idaho and are in the collection of the United States Geological Survey. The originals of Figures 1, 14, and 

17 came from locality 1, 5 miles east of Grays Lake; the originals of Figures 4, 10, and 11 from locality 5, 1 mile 

east of Hot Springs, at the north end of Bear Lake; the originals of Figures 5 and 7 from locality 3, head of Wood 

Canyon, Aspen Mountains, 9 miles east of Soda Springs.

146
U. 8. GEOLOGICAL SURVEY PROFESSIONAL PAPER 167 PLATE 33

X 2

Xl'/2

xi)4

X 1/2

11

10

12

\J

14

18 19 X 5 20

X 2

LOWER TRIASSIC AMMONOIDS
U. S. GEOLOGICAL SURVEY PHOFESSIONAL PAPER 167 PLATE 34

i

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LOWER TRIASSIC AMMONOIDS
PLATE 34

FIG nines 1-6. Meekoceras cristalum Smith, n. sp. (p. 56). 

1-3. Type. 

4-6. Early adult stage.

The originals of the figures in this plate were collected by J. P. Smith in the Lower Triassic Meekoceras zone in southeastern Idaho, at locality 5, 1 mile east of Hot Springs at the north end of Bear Lake. They are in the collection 

of the United States Geological Survey.

147
PLATE 35

FIGURES 1-3. Meekoceras evansi Smith, n. sp. (p. 60). Type.

The original specimen was collected by J. P. Smith in the Lower Triassic Meekoceras zone, at locality 5, 1 mile east 

of Hot Springs, at the north end of Bear Lake, southeastern Idaho. It is in the collection of the United States 

Geological Survey.

148
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LOWER TRIASSIC AMMONOIDS
U. S. GEOLOGICAL SURVEY PROFESSIONAL PAPER 167 PLATE 36

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U J

11

X3

12 13 14

v t ^^^^ V

18

15 16 17

21 * 

19

I

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24 X '° ' 28 

LOWER TRIASSIC AMMONOIDS

26 27
PLATE 36

FIGURES 1-18. Meekoceras evansi Smith, n. sp. (p. 60).

1. Early mature stage, showing sculpture.

2-4. Early mature stage.

5, 6. Early mature stage, diameter 27 millimeters, broken so as to show the larval coil inside. Side view and front view 

of the interior coils.

7, S. Adolescent stage, diameter 17 millimeters, showing transition from Lecanites to Xenodiscus at 6 millimeters, and from 

Xenodiscus to Meekoceras at 15 millimeters.

9-11. Adolescent stage, diameter 9 millimeters, showing transition from Lecanites to Xenodiscus.

12-14. Larval stage, transitional from Prolecanites to Lecanites, diameter 4.5 millimeters.

15-18. Larval stage, diameter 3.5 millimeters, corresponding to Prolecanites. 

FIGURES 19-28. Meekoceras gracilitatis White (p. 57).

19-21. Larval stage, diameter 5 millimeters, corresponding to Lecanites.

22-25. Larval stage, diameter 2 millimeters, transitional to Prolecanites.

26-28. Adolescent stage, diameter 16 millimeters, showing transition from goniatitic to serrated stage at 13 millimeters.

The originals of all figures in this plate were collected by J. P. Smith in the Lower Triassic Meekoceras zone, of southeastern Idaho and are in the collection of the United States Geological Survey. The originals of Figures 1, 2, 5, 

7, 9, 12, 15, and 19 came from locality 1, 5 miles east of Grays Lake; the original of Figure 22 from locality 5, 

1 mile east of Hot Springs, at north end of Bear Lake.

149
PLATE 37

FIGURES 1-7. Meekoceras gracilitatis White (p. 57).

1.;Aged specimen, showing aperture.

2. 3. Large specimen.

4. Perfect specimen showing sculpture of shell.

5-7. Early mature stage, broken so as to show the goniatite stage of the inner whorl; shell, septum of the outer whorl, and

septum of the inner whorl, goniatite stage. 

The specimens figured in this plate were collected by J. P. Smith in the Lower Triassic Meekoceras zone of southeastern

Idaho and are in the collection of the United States Geological Survey. The originals of Figures 1, 2, and 5 came

from locality 1, 5 miles east of Grays Lake; the original of Figure 4 from locality 3, head of Wood Canyon, 9 miles

east of Soda Springs.

150
U. S. GEOLOGICAL SUBVEY PROFESSIONAL PAPER 167 PLATE 37

rv

X 2

67GG4 32 13 LOWER TRIASSIC AMMONOIDS
U. S. GEOLOGICAL SURVEY PROFESSIONAL PAPER 167 PLATE 38

Xl'/fc

LOWER TRIASSIC AMMONOIDS
PLATE 38

FIGURE 1. Meekoceras mushbachanum White var. corrugala Smith, n. var. (p. 61). Type. 

FIGURES 2-6. Meekoceras gracilitatis White (p. 57). 

2, 3. Mature specimen with shell removed. 

4-6. Mature shell broken so as to show the adolescent stage inside; shell, septum of mature stage, and septum of adolescent

stage.

The originals of the figures in this plate were collected by J. P. Smith in the Lower Triassic Meekoceras zone of southeastern Idaho and are in the collection of the United States Geological Survey; the originals of Figures 1 and 2 

came from locality 5, 1 mile east of Hot Springs, north end of Bear Lake; the original of Figure 4 from locality 

1, 5 miles east of Grays Lake.

151
PLATE 39

FIGURES 1, 2. Flemingites aplanatus (White) (p. 51). Side view and septum. 

FIGURES 3-8. Xenodiscus waageni Hyatt.and Smith (p. 46). 

3, 4. Side and front views.

5. Septum of the same specimen.

6. 7. Smaller specimen. 

8. Septum of the same specimen.

FIGURES 9-12. Lecanites (Paralecanites) arnoldi Hyatt and Smith (p. 41). 

9-11. Adult stage. 

12. Septum of the same specimen.

All specimens figured in this plate came from Lower Triassic Meekoceras zone, Union Wash, Inyo Range, Inyo County, 

Calif. Collection of United States National Museum.
U. S. GEOLOGICAL SURVEY PROFESSIONAL PAPER 167 PLATE 39

Iff

11

12 X6 

LOWER TRIASS1C AMMONOIDS
U. S. GEOLOGICAL SURVEY PROFESSIONAL PAPER 107 PLATE 40

XI '/z

LOWER TRIASSIC AMMONOIDS
PLATE 40

FIGURES .1-8. Inyoites oweni Hyatt and Smith (p. SO).

1. Septum of a young specimen; diameter 3 millimeters.

2. 3. Adolescent stage; diameter 33 millimeters.

4, 5. Above specimen, with one-third of a revolution removed, giving a diameter of 22 millimeters.

6, 7. The same specimen, with another third of a revolution removed, giving a diameter of 17 millimeters.

8. Septum of the same specimen. 

FIGURES 9-11. Lanceolites compactus Hyatt and Smith (p. 90).

9. 10. Mature specimen; diameter 65 millimeters. 

11. Septum of the same specimen.

All specimens figured in this plate came from Lower Triassic Owenites subzone of the Meekoceras zone, Union Wash, 

Inyo Range, Inyo County, Calif. Collection of United States National Museum.

153
PLATE 41

FIGTJKES 1-10. Hedenstroemia kossmati Hyatt and Smith (p. 78).

1. Side view of an adult specimen.

2. Septum of the same specimen.

3-5. Adolescent stage; diameter 23 millimeters.

6. Septum of the same specimen.

7. Septum of another specimen; diameter 20 millimeters. 

8-10. End of larval stage; diameter 5.5 millimeters.

From Lower Triassic Meekoceras zone, Wood Canyon, Aspen Ridge, 9 miles east of Soda Springs, Idaho. Collection

of United States National Museum. 

154
U. S. GEOLOGICAL, SURVEY PROFESSIONAL PAPER 167 PLATE 41

.4

LOWER TRIASSIC AMMONOIDS
U. S. GEOLOGICAL SURVEY PROFESSIONAL PAPER 167 PLATE 42

LOWER TRIASSIC AMMONOIDS
PLATE 42

FIGURES 1-8. Ussitria ivaageni Hyatt and Smith (p. 92).

1-3. Left side, front, and rear views, transition from Dimorphoceras to Thalassoceras; diameter 11 millimeters.

4. Septum of the same specimen.

5-7. Right side, front, and rear views, Dimorphoceras stage; diameter 5.5 millimeters.

8. Septum of the same specimen.

From Lower Triassic Meekoceras zone, Wood Canyon, Aspen Ridge, 9 miles east of Soda Springs, Idaho. Collection

of United States National Museum. 

FIGURE 9. Septum of Thalassoceras phillipsi Gemmellaro (for comparison). (Copied from Frech, Fritz, Lethaea geognostica,

Teil 1, Das Palaeozoicum, Band 2, Lief. 3, fig. 8.) 

FIGURE 10. Septum of Thalassoceras gemmellaroi Karpinsky (for comparison). (Copied from Karpinsky, A., Ammoneen der

Artinsk Stufe, pi. 4, fig. 3c.) 

FIGURE 11. Septum of Dimorphoceras atratum Goldfuss (for comparison). (Copied from Frech, Fritz, Lethaea geognostica, Teil 1,

Das Palaeozoicum, Band 2, Lief. 2, pi. 46b, fig. lib.) 

FIGURE 12. Septum of Dimorphoceras gilbertsoni Phillips (for comparison). (Copied from Foord and Crick, Catalogue of

fossil Cephalopoda, British Museum, pt. 3, p. 221, fig. 105.) 

FIGURE 13. Septum of Ussuria iwanowi Diener (for comparison). (Copied from Diener, Carl, Triadische Cephalopodenfaunen

der ostsibirischen Kiistenprovinz: Com. g6ol. [St.-Pe"tersbourg] M(5m., vol. 14, No. 3, pi. 3, fig. 5, 1895. 

FIGURES 14-20. Cordillerites angulatus Hyatt and Smith (p. 96). 

14, 15. Adolescent stage; diameter 15 millimeters. 

16. Septum of the same specimen. 

17-19. Larval stage; diameter 6.5 millimeters. 

20. Septum of the same specimen.

From Lower Triassic Meekoceras zone, Wood Canyon, Aspen Ridge, 9 miles east of Soda Springs, Idaho. Collection of United States National Museum.

155
PLATE 43

FIGURES 1-3. Goniolobocerds welleri Smith (p. 24). .Type, refigured. Cisco group (Pennsylvanian), Graham, Tex. 

FIGURES 4-7. Neodimorphoceras texanum Smith (p. 23). Type, refigured. Cisco group (Pennsylvanian), Graham, Tex. 

FIGURES 8-13. Gastrioceras listeri Martin (p. 24). Typical specimen, Middle Coal Measures, Manchester, England. Larval

stages. 

FIGURES 14-17. Gastrioceras welleri Smith (p. 24). Typical specimen, from the "Upper Coal Measures" (Pennsylvanian) at

Howard, Kans.

FIGURES 18-20. Marathonites ganii Smith (p. 24). . "Upper Coal Measures" (Pennsylvanian) at Howard, Kans. 

FIGURE 21. Prodromites gorbyi Miller (p. 24). Typical specimen. Chouteau limestone (Mississippian), Pettis County, Mo. 

FIGURES 22-24. Agathiceras ciscoense Smith (p. 24). Type, refigured. Cisco group (Pennsylvanian), Graham, Young County, Tex. 

Figures 1-7 and 21-24 are from U. S. Geol. Survey Mon. 42 (The Carboniferous ammonoids of America). These

figures are introduced here for comparison with young stages of Triassic ammonites. This plate is reprinted from

Plate 20, U. S. Geol. Survey Prof. Paper 141, 1927.

156
U. S. GEOLOGICAL SURVEY PROFESSIONAL PAPER 167 PLATE 43

24

22 21

V

LOWER TRIASSIC AMMONOIDS
TJ. S. GEOLOGICAL SURVEY PROFESSIONAL PAPER 167 PLATE 44

10

LOWER TRIASSIC AMMONOIDS
PLATE 44

FIOTJUE 1. Prolecanites applanatus Frech (p. 23). Lower Carboniferous, Krumberg, Germany. (After Holzapfel, E., Die Cephalo 

t ( podenfiihrenden Kalke des Unteren Carbon von Erdbach-Breitscheid bei Herborn: Paleont. Abh. (Dames & Kay 

"' ser), n. F., Band 1, pi. 5, fig. 1.) 

FIGURES 2-4. Timanites acutus Keyserling (p. 24). Upper Devonian, Timan, Russia. (After Holzapfel, E., Die Cephalopoden

des Domanik im siidlichen Timan: Com. giSol. [St.-Pe'tersbourg] Mdm., vol. 12, No. 3, pi. 7, figs. 6, 6b, 7.) 

FIGURE 5. Beloceras multilobatum Beyrich (p. 24). Upper Devonian, Cabrieres, France. (After Frech, Fritz, Lethaea geoghostica, Teil 1, Das Palaeozoicum, Band 2, Lief. 1, pi. 32a, fig. 9a.) 

FIGURES 6-8. Gepkyroceras regale Holzapfel (p. 23). Upper Devonian, Timan, Russia. (After Holzapfel, E., Die Cephalopoden

des Domanik im siidlichen Timan: Com. g6ol. ISt.-Petersbourg] M6m., vol. 12, No. 3, pi. 3, figs. 5, 5a, 5c.) 

FIGURE 9. Acrocanites mullilobatus Schindewolf (p. 89). Lower Carboniferous. (After Schindewolf, 0. H., Ueber eine Unterkarbonfauua aus Ostthuringen: Senckenbergiana, vol. 4, Heft 1, 2, p. 15, fig. 2d.) 

FIGURES 10-14. Paraceltiles mullicostatus Bose (p. 41).

10, 11. From Delaware Mountain formation, lower Permian, near Van Horn, Culberson County, Tex.

12-14. From Word formation, lower Permian, Nos. 17-34. Section N. 55° W. from Hess ranch house, near Marathon,

Brewster County, Tex. 

These Paleozoic species are introduced here for comparison with young stages of Triassic ammonites.

157
PLATE 45

FIGURES 1-3. Aphyllites (Agoniatites) marcellensis Hall (p. 23). Middle Devonian. (After a specimen in the Stanford collection.) 

FIGURES 4, 5. Pronorites iimorensis Haniel (p. 24). Lower Permian, Somohole, Timor. (After a specimen in the Stanford

collection.) 

FIGURES 6-8. Gastrioceras (Paragastribceras) zitteli Gemmellaro (p. 24). Lower Permian, Sicily. (After Gemmellaro, G. G., La

fauna dei calcari con Fusulina della Valle del Fiume Sosio nella Provincia di Palermo, pi. 6, figs. 21-23, 1887.) 

FIGURES 9-11. Adrianites timorensis Boehm (p. 24). Middle Permian, Timor. (After Haniel, C., Die Cephalopoden der Dyas

von Timor: Palaeontologie von Timor, Lief. 3, pi. 50, figs. 7a, 7b, 11.) 

FIGURES 12-15. Uddenites schucherti Bose (p. 24).

12, 13. Lower Permian, Wolfcamp formation, Glass Mountains, Tex. (After Smith, J. P., Am. Jour. Sci., 5th ser., vol.

17, p. 72, 1929.) 12, Pronorites stage; diameter 5.5 millimeters. 13, Transitional toward Uddenites; diameter

10 millimeters.

14, 15. Same locality and horizon as Figures 12 and 13. Adult shell and septum. 

FIGURES 16, 17. Sageceras gabbi Mojsisovics (p. 89).

16. Septum. Middle Triassic, Fossil Hill, West Humboldt Range, Nev. Larval-stage, diameter 45 millimeters.

17. Middle Triassic, same locality as specimen shown in Figure 16. Adolescent stage, diameter 7 millimeters.

158
U. S. GEOLOGICAL SURVEY PKOFESSIONAL PAPER 167 PLATE 45

15

16 X 18

67664 32 14

LOWER TRIASSIC AMMONOIDS
U. S. GEOLOGICAL SURVEY PROFESSIONAL PAPER 167 PLATE 46

Xl'/fe

10

13

11

V

r

§12

X3

20

LOWER TRIASSIC AMMONOIDS
PLATE 46

FIGURES 1-13. Columbites consanguineus Smith, n. sp. (p. 106). 

1, 2. Type.

3, 4. Adult showing septum. 

5, 6. Adolescent stage; diameter 28 millimeters.

7-9. Adolescent stage, diameter 13 millimeters, corresponding to Paragastrioceras. 

10-13. Adolescent stage, diameter 8.5 millimeters, corresponding to Gastrioceras. 

FIGURES 14-21. Columbites ornatus Smith, n. sp. (p. 107). 

14, 15. Type.

16-18. Early mature stage, diameter 25 millimeters. 

19-21. Adolescent stage, diameter 9 millimeters, corresponding to Paragastrioceras.

All specimens figured in this plate came from the Lower Triassic Cohimbites zone, 1 mile west of Paris, Idaho, and are 

in the collection of the United States Geological Survey.

159
PLATE 47

FIGURES 1-8. Columbites ligatus Smith, n. sp. (p. 106). 

1-3. Type. 

4, 5. Adult shell. 

6-8. Adult shell.

FIGURES 9, 10. Columbites 'minimus Smith, 11. sp. (p. 106). Type. 

FIGURES 11-23. Celtites ursensis Smith, n.-sp. (p. 104). 

11, 12. Type.

13, 14. Shell and spiral lines.

15-17. Adult shell, showing septum and surface sculpture. 

18-20. Adult shell. 

21-23. Late larval stage, corresponding to Paragastrioceras; diameter 5.5 millimeters.

The originals of all figures on this plate came from the Lower Triassic Columbites zone, 1 mile west of Paris, Idaho, 

and are in the collection of the United States Geological Survey.

160
U. S. GEOLOGICAL SURVEY PROFESSIONAL PAPER 167 PLATE 47

10

15 22

I

18 19 20 X3

17 23

LOWER TRIASSIC AMMONOIDS
TJ. S. GEOLOGICAL SURVEY PROFESSIONAL PAPER 167 PLATE 48

2 y

LOWER TRIASSIC AMMONOIDS
PLATE 48

FIGURES 1-10. Celtites apostolicus Smith, n. sp. (p. 104).

I,2. Type.

3, 4. Shell and sculpture.

5-7. Shell, diameter 18 millimeters, and septum.

S-10. Adolescent stage, diameter 7 millimeters; corresponding to Gastrioceras. 

FIGURES 11-20. Celtites planovolvis Smith, n. sp. (p. 104).

II, 12. Type. 

13-15. Adult shell.

16. Septum from specimen at diameter 15 millimeters.

17 20. Adolescent stage, diameter 6.5 millimeters, corresponding to Gastrioceras. 

FIGU.UES 21-30. Meekoceras curticostatum Smith, n. sp. (p. 56). 

21, 22. Type. 

23, 24. Adult shell. 

25, 26. Adult shell. 

27, 28. Adult shell. 

29, 30. Shell and septum, showing transition from Lecanites to Xenodiscus.

The originals of all figures on this plate came from the Lower Triassic Columbites zone, 1 mile west of Paris, Idaho, 

and are in the collection of the United States Geological Survey.

161
PLATE 49

FIGURES 1-4. Meekoceras sanctorum Smith, n. sp. (p. 59).

1, 2. Type.

3, 4. Paratype, showing septum. 

FIGURES 5-11. Meekoceras micromphalus Smith, n. sp. (p. 58).

5-8. Type.

9-11. Adolescent stage, diameter 17 millimeters. 

FIGURES 12-16. Tirolites illyricus Mojsisovics (p. 84).

12, 13. Adult shell.

14-16. Adolescent stage, diameter 9 millimeters, showing transition from Xenodiscus to Paratirolites. ' 

FIGURES 17-19. Pseudharpoceras idahoense Smith, n. sp. (p. 81). Type.

The originals of all figures in this plate came from the Lower Triassic Columbites zone, 1 mile west of Paris. Idaho, 

and are in the collection of the United States Geological Survey.

162
U. S. GEOLOGICAL SURVEY PROFESSIONAL PAPER 167 PLATE 49

18

LOWER TRIASSIC AMMONOIDS
U. S. GEOLOGICAL SURVEY PROFESSIONAL PAPER 167 PLATE 50

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LOWER THIASSIC AMMONOIDS
PLATE 50

FIGURES 1-4. Meekoceras luberculalum Smith, n. sp. (p. 62). 

1-3. Type. 

4. Septum of another specimen.

The specimens figured in this plate came from the Lower Triassic Meekoceras zone, Owenites subzone, of Union 

Wash, Inyo Mountains, about 15 miles southeast of Independence, 'Inyo County, Calif. They were collected by 

J. P. Smith and are in the collection of the United States Geological Survey.

163
PLATE 51

FIGURES 1-4. Meekoceras radiosum Waagen (p. 59). 

1, 2. Adult shell. 

3, 4. Adult shell.

FIGURES 5, 6. Sturia woodini Smith, n. sp. (p. 94). Type. 

FIGURES 7-10. Anasibirites desertorum Smith, n. sp. (p. 71). 

7, 8. Type. 

9, 10. Adult shell. 

FIGURES 11-13. Clypeoceras pusillum Smith, n. sp. (p. 64). Type.

All specimens figured in this plate came from the Lower Triassic Meekoceras zone, Owenites subzone, of Union Wash, 

Inyo Mountains, about 15 miles southeast of Independence, Inyo County, Calif. They were collected by J. P. 

Smith and are in the collection of the United States Geological Survey.

164
U. S. GEOLOGICAL SURVEY PROFESSIONAL PAPER 167 PLATE 51

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U. S. GEOLOGICAL SURVEY PROFESSIONAL PAPER 167 PLATE 52

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11

X 2

20

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LOWER TRIASSIC AMMONOIDS
PLATE 52

FIGURES 1-5. Oiveniles zilteli Smith, n. sp. (p. 101). 

1-3. Type. 

4, 5. Adult shell.

FIGURES 6-8. Oivenites egrediens Welter (p. 101). Adult specimen. 

FIGURES 9-11. Meekoceras patelliforme Smith, n. sp. (p. 58). Adult stage. 

FIGURES 12-17. Meekoceras strongi Smith, n. sp. (p. 62). 

12-14. Type. 

15-17. Adolescent stage. 

FIGURES 18-20. Proptychites walcotti Hyatt and Smith (p. 102).

All specimens figured in this plate were collected by J. P. Smith in the Meekoceras zone, Owenites subzone, Union 

Wash, Inyo Mountains, 15 miles southeast of Independence, Inyo County, Calif. Collection of United States 

National Museum.

165
PLATE 53

FIGURES 1. Meekoceras (Koninckites) newberryi Smith, n. sp. (p. 62). , 

1-3. Type.

4. Septum of another specimen.

FIGURES 5-8. Proleusites rolundus Smith, n. sp. (p. 102). 

5,6. Type.

7, 8. Another specimen.

FIGURES 9-12. Xenodiscus toulai Smith, n. sp. (p. 45). Type. 

FIGURES 13-17. Anasibirites lindgreni Smith, n. sp. (p. 73). 

13-15. Type. 

16, 17. Adolescent specimen.

All specimens figured in this plate were collected by J. P. Smith in the Lower Triassic Meekoceras zone, Oroenites 

subzone, Union Wash, Inyo Mountains, about 15 miles southeast of Independence, Inyo County, Calif. Collection 

of United States National Museum. 

166
U. S. GEOLOGICAL SURVEY PROFESSIONAL PAPER 167 PLATE 53

16 17

10

11

12

67664 32 15 LOWER TRIASSIC AMMONOIDS

14 15
U. S. GEOLOGICAL SURVEY PROFESSIONAL PAPER 167 PLATE 54

X 2

LOWER TRIASSIC AMMONOIDS
PLATE 54 .

FIGURES 1-17. Ophiceras sakunlala Diener (p. 50). 

1, 2. Mature stage. 

3-5. Younger shell. 

6-8. Xenodiscus stage. 

9-12. Transition from Lecanites to Xenodiscus, diameter 10 millimeters; 11, septum at diameter of 10 millimeters; 12, septum

at diameter of 8 millimeters. 

13, 14. Xenodiscus stage, diameter 9 millimeters. 

15-17. Transition from Prolecanites through Lecanites to Xenodiscus. 

FIGURES 18-24. Ophiceras subquadratum Smith, n. sp. (p. 50). 

18-20. Type.

21-24. Adolescent stage, diameter 20 millimeters, showing transition from Lecanites through Xenodiscus to Ophiceras, 23 

septum in Ophiceras stage, at diameter of 20 millimeters; 24, septum in Lecanites stage, diameter 9.5 millimeters. 

FIGURES 25-30. Ophiceras parvum Smith, n. sp. (p. 49). 

25-27. Type.

28-30. Adolescent stage, diameter 9 millimeters, corresponding to Lecanites. 

FIGURES 31-34. Owenites carpenteri Smith, n. sp. (p. 100). 

31, 32. Type. 

33, 34. Shell; septum.

All specimens figured in this plate were collected by J. P. Smith, in the Lower Triassic Meekoceras zone, Owenites subzone, of. Union Wash, Inyo Mountains, about 15 miles southeast of Independence, Inyo County, Calif. They are 

in the collection of the United States Geological Survey.

167
PLATE 55

FIGURES 1-13: Lanceolites bicarinatus Smith, n. sp. (p. 90).

I-3. Type.

4, 5. Adult shell.

6, 7. Adult shell.

8-10. Adolescent stage.

II-13. Larval stage, diameter 6 millimeters, corresponding to Aphyllites. 

FIGURES 14-16. Meekoceras elkoense Smith, n. sp. (p. 56). Type.

The specimens figured in this plate were collected by J. P. Smith in the Lower Triassic Meekoceras zone, Oweniles subzone. Originals of Figures 1-4 and 14-16 came from Phelan ranch, mouth of Cottonwood Canyon, east side of 

Ruby Range, about 70 miles south of Wells, Elko County, Nev. Originals of Figures 5-13 came from Union Wash, 

Inyo Mountains, 15 miles southeast of Independence, Inyo County, Calif. Collection of United States National 

Museum.

168
U. S. GEOLOGICAL SURVEY PROFESSIONAL PAPER 167 PLATE 55

X1/2

11

10

I

12

16

xil

LOWER TRIASSIC AMMONOIDS
U. S. GEOLOGICAL SURVEY PROFESSIONAL PAPER 167 PLATE 56

X2

12

15 18

LOWER TRIASSIC AMMONOIDS
FIGURES 1-5. Xenodiscus nevadanus Smith, n. sp. (p. 47). 

1, 2. Type. 

3, 4. Paratype.

5. Slab containing two large septate specimens. 

FIGURES 6-12. Xenodiscus nivalis Diener (p. 44).

6. 7. Adult shell. 

8, 9. Adult shell. 

10-12. Adolescent stage.

FIGURES 13-18. Ophiceras sakuntala Diener (p. 50). 

13-15. Adult shell. 

16-18. Adult shell. 

FIGURES 19, 20. Anasibirites desertorum Smith, n. sp. (p. 71).

All specimens figured in this plate were collected by J. P. Smith in the Lower Triassic Meekoceras zone, Oweniles subzone. Originals of Figures 1-18 came from Phelan ranch, Cottonwood Canyon, east side of Ruby Range, 70 miles 

south of Wells, Elko County, Nev. Originals of Figures 19 and 20 came from Rohner ranch (locality 4), south 

side of Paris Canyon, 1 mile west of Paris, Idaho. Collection of United States National Museum.

169
PLATE 57

FIGURES 1-4. Tirolites knighti Smith, n. sp. (p. 84). 

1, 2. Type. " ' 

3, 4. Paratype. 

FIGURES 5-8. Tirolites pealei Smith, n. sp. (p. 84).

5, 6. Type. . , ' . - . 

7, 8. Another specimen.

FIGURES 9, 10. Tirolites harti Smith (p. 83). Type.

FIGURES 11-13. Dalmatites attenuatus Smith, n. sp. (p. 81). Type. . . . . All specimens figured in this plate were collected by J. P. Smith in the Lower Triassic Tirolites zone, Paris Canyon,

\}'i miles west of Paris, Idaho. Collection of United States National Museum. 

170 . . . -
U. S. GEOLOGICAL SURVEY PROFESSIONAL PAPER 167 PLATE 57

10 12

LOWER TRIASSIC AMMONOIDS

13 X 1X2

11
U. S. GEOLOGICAL SURVET PROFESSIONAL PAPER 167 PLATE 58

.X 5

X 10

X 10

12 x 10

X 6

13

X 8

14

X 6 1|<B^F X 6

16 17

18 19 20

X3

42

LOWER TRIASSIC AMMONOIDS
PLATE 58 

RECAPITULATION OF GASTRIOCERAN STAGES OF GROWTH IN TRIASSIC GASTRIOCERATEA

FIGURES 1 3. 7\opigaslrites trojanus Smith (p. 22). Larval stage, diameter 4.5 millimeters. Middle Triassic, Nevada-. 

FIGURES 4-6. Tropigaslrites halli Mojsisovics (p. 22). Larval stage, diameter 4 millimeters. Middle Triassic, Nevada. 

FIGURES 7-9. Tropigaslrites lahontanus Smith (p. 22). Larval stage, diameter 3.5 millimeters. 

FIGURES 10-12. Columbites spencei Smith (p. 22). Larval stage, diameter 4.5 millimeters. Lower Triassic, Idaho. 

FIGURES 13-15. Tropites torquillus Mojsisovics (p. 22). Larval stage, diameter 2 millimeters. Upper Triassic, California. 

FIGURES 16-18. Tropites welleri Smith (p. 22). Larval stage, diameter 2.5 millimeters. Upper Triassic, California. 

FIGURES 19-21. Tropites occidentalis Smith (p. 22). Larval stage, diameter 6 millimeters. Upper Triassic, California. 

FIGURES 22-24. Tropites subbullatus Hauer (p. 22). Larval stage, diameter 1.83 millimeters. Upper Triassic, California. 

FIGURES 25-27. Paratropites sellai Mojsisovics (p. 22). Larval stage, diameter 2.3 millimeters. Upper Triassic, California. 

FIGURES 28-31. Discotropites sandlingensis Hauer (p. 22). Upper Triassic, California. 

28, 29. Larval stage, diameter 3.2 millimeters. 

30, 31. Larval stage, diameter 2.68 millimeters.

FIGURES 32-35. Discolropites mojsvarensis Smith (p. 22). Larval stage, diameter 3 millimeters. Upper Triassic, California. 

FIGURES 36, 37. Sagenites herbichi Mojsisovics (p. 22). Larval stage, diameter 2.4 millimeters. Upper Triassic, California. 

FIGURES 38-40. Juvavites siibintermittens Hyatt and Smith (p. 22). Larval stage, diameter 5 millimeters. Upper Triassic, California.

FIGURES 41-43. Metasibirites frechi Hyatt and Smith (p. 22). Larval stage, diameter 4.5 millimeters. Upper Triassic, California. 

FIGURE 44. Juvavites brockensis Smith (p. 22). Larval stage, diameter 5 millimeters.

The figures in this plate are introduced to show the similarity of larval stages of growth of Triassic ammonites to 

their Carboniferous predecessors and supposed ancestors. Figures 1-12 are from U. S. Geol. Survey Prof. Paper 

83 (figs. 1-3, pi. 17; figs. 4-6, pi. 18; figs. 7-9, pi. 19; figs. 10-12, pi. 71). Figures 13-44 are from U. S. Geol. Survey 

Prof. Paper 141 (figs. 13-15, pi. 68; figs. 16-18, pi. 78; figs. 19-21, pi. 70; figs. 22-24, pi. 79; figs. 25-27, pi. 31; 

figs. 28-31, pi. 36; figs. 32-35, pi. 8; figs. 36, 37, pi. 28; figs. 38-40, pi. 16; figs. 41-43, pi. 60; fig. 44, pi. 16).

171
PLATE 59

RECAPITULATION OF ADRIANITES STAGES OF GROWTH IN THE AGATHICERATEA BRANCH OF TRIASSIC

GASTRIOCERATEA

FIGURES 1-3. Arcestes pacificus Hyatt and Smith (p. 22). Upper Triassic, California.

1, 2. Larval stage, diameter 3 millimeters, transitional from Adrianites to Marathonites.

3. Larval stage, younger part of same specimen, diameter 2.0 millimeters, corresponding to Adrianites. 

FIGURES 4-7. Arcestes traski Smith (p. 22). Upper Triassic, California.

4-6. Larval stage, diameter 3 millimeters.

7. Larval stage, younger part of same specimen, diameter 2.5 millimeters; showing transition from Adrianites to primitive 

Marathonites.

RECAPITULATION OF LECANITES AND PROLECANITES STAGES IN TRIASSIC CERATITOIDEA

FIGURES 8-10. Lecanites arnoldi Hyatt and Smith (p. 22). Larval stage, corresponding to Prolecanites, diameter 3.36 millimeters.

Lower Triassic, Idaho.

FIGURES 11-16. Xenodiscus bittneri Hyatt and Smith (p. 22). Middle Triassic, California. 

11-13. Larval stage, corresponding to Prolecanites, diameter 2.20 millimeters. 

14-16. Larval stage, diameter 4 millimeters, corresponding to Lecanites. 

FIGURES 17-21. Meekoceras mushbachanum White (p. 22). Lower Triassic, Idaho. 

17, 18. Larval stage, corresponding to Prolecanites, diameter 4 millimeters. 

19-21. Adolescent stage, corresponding to Lecanites, diameter 10 millimeters. 

FIGURES 22-24. Beyrichites rotelliformis White (p. 22). Larval stage, diameter 3.4 millimeters, corresponding to Lecanites. Middle

Triassic, Nevada. 

FIGURES 25-27. Gymnoticeras blakei Gabb (p. 22). Larval stage, diameter 3 millimeters, corresponding to Lecanites. Middle

Triassic, Nevada. 

FIGURES 28, 29. Hollandites organi Smith (p. 22). Adolescent stage, corresponding to Lecanites, diameter 11 millimeters. Middle

Triassic, Nevada. 

FIGURES 30-32. Nevadites merriami Smith (p. 22). Larval stage, corresponding to transition from Lecanites to primitive Xenodiscus,

diameter 6.5 millimeters. Middle Triassic, Nevada. 

FIGURES 33-35. Arpadites gabbi Hyatt and Smith (p. 22). Larval stage, diameter 3.46 millimeters; transitional from Prolecanites

to Lecanites. Upper Triassic, California.

The figures in this plate are introduced for comparison of larval stages of Triassic ammonites with antecedent and 

supposedly ancestral Paleozoic or early genera. Figures 1-3, 4-7, 33-35, from U. S. Geol. Survey Prof. Paper 141, 

pis. 23, 22, 83; Figures 8-10 from U. S. Geol. Survey Prof. Paper 40, pi. 64; Figures 11-16, 17-21, 22-24, 25-27, 28-29, 

30-32 from U. S. Geol. Survey Prof. Paper 83, pis, 2, 74, 8, 66, 55, 8. 

172
TJ. S. GEOLOGICAL SURVEY PROFESSIONAL PAPER 167 PLATE S9

2 xio 

»

^H^ X4

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32

X 5

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LOWER TRIASSIC AMMONOIDS
H. S. GEOLOGICAL SUEVEY PBOFESSIONAL PAPER 167 PLATE 60

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29 30 X2

LOWER TRIASSIC AMMONOIDS
PLATE 60

FIGURES 1-3. Sageceras gabbi Mojsisovics (p. 22). Middle Triassic, Nevada.

1. Larval stage, diameter 4.5 millimeters; transitional from Gephyroceras toward Beloceras.

2. Late larval stage, diameter 7 millimeters; transitional from Beloceras toward primitive Sageceras.

3. Adolescent stage, diameter 18 millimeters. 

FIGURES 4-6. Aspenites acidus Hyatt and Smith (p. 22).' Lower Triassic, Idaho.

4. Larval stage, transitional toward Gephyroceras, diameter 2 millimeters.

5. Larval stage, corresponding to Gephyroceras, diameter 2.75 millimeters.

6. Larval stage, corresponding to Timaniles, diameter 5 millimeters.

FIGURES 7-9. Dieneria arthaberi Hyatt and Smith (p. 22). Larval stage, diameter 3.6 millimeters. Upper Triassic, Calif. 

FIGURE 10. LanceoUles compactus Hyatt and Smith (p. 22). Larval stage, diameter 4.5 millimeters; corresponding to Aphylliles.

Lower Triassic, Idaho. 

FIGURES 11-13. Fremonlites ashleyi Hyatt and Smith (p. 22). Larval stage, diameter 8 millimeters; corresponding to Aphyllites.

Upper Triassic, California. 

FIGURE 14. Cordillerites angulatus Hyatt and Smith (p. 22). Larval stage, showing development from the Prolecanites to the

Pronoriles stage, diameter 6.5 millimeters. Lower Triassic, Idaho. 

FIGURES 15-20. Ussuria waageni Hyatt and Smith (p. 22). Lower Triassic, Idaho. 

15-17. Larval stage, diameter 1.8 millimeters; corresponding to Gephyroceras. 

18-20. Larval stage, diameter 4.4 millimeters; corresponding to Dimorphoceras. 

FIGURES 21-23. Eutomoceras laubei Meek (p. 22). Larval stage, diameter 2.5 millimeters; corresponding to Lecanites. Middle

Triassic, Nevada. 

FIGURES 24-26. Dalmatites parvus Smith (p. 22). Larval stage, diameter 7 millimeters; corresponding to Lecanites. Middle

Triassic, Nevada. 

FIGURES 27, 28. Longobardiles nevadanus Hyatt and Smith (p. 22). Larval stage, diameter 4 millimeters. Middle Triassic,

Nevada. 

FIGURES 29-31. Discophyllites patens Mojsisovics (p. 22). Larval stage, diameter 5 millimeters; septa drawn from same specimen

at diameter of 2 millimeters, showing transition from goniatite stage to primitive Xenodiscus. Upper Triassic,

California. 

FIGURIS 32. Pseudosageceras multilobatum Noetling (p. 22). Larval stage, diameter 5.5 millimeters; corresponding to Beloceras.

Lower Triassic, Idaho. 

The figures in this'plate are introduced to show comparison of young stages of Triassic ammonites with Paleozoic

antecedents and supposed ancestors. Figures 1, 2, 4-6, 10, and 32 are originals; Figure 14 is from U. S. Geol.

Survey Prof. Paper 40, pi. 71; Figures 7-9, 11-13, 15-20, 29-31 from U. S. Geol. Survey Prof. Pape,r 141, pis. 81,

63, 21, 62; Figures 3, 21-23, 24-26, 27-28 from U. S. Geol. Survey Prof. Paper 83, pis. 12, 27, 30, 12.

173
PLATE 61

FIGURES 1-21. Columbites parisianus Hyatt and Smith (p. 107).

1. Mature specimen, showing the body chamber to be one revolution in length, also the obsolescence of sculpture at maturity.

2-4. Side and front views and septum, early maturity.

5-7. Side, front, and rear views, to show the sculpture on both shell.and past. 

8, 9. Side and front views, end of adolescent stage; diameter 33 millimeters.

10. Front view, broken, showing the inner whorl; diameter 28 millimeters.

11. 12. Side and front views of whole specimen, adolescent stage; diameter 26 millimeters.

13. Front view of broken whorl of same specimen, showing the inner whorl.

14. 15. Side and front views, showing Gastrioceras stage of growth, adolescent stage, diameter 16 millimeters. 

16-18. Side and front views and septa, early adolescent stage; diameter 10 millimeters. 

19-21. Side, front, and rear views, early adolescent stage; diameter 3.32 millimeters.

From Lower Triassic, Columbites zone, 1 mile west of Paris, Idaho (locality 1981, United States Geological Survey).

174 -
U. S. GEOLOGICAL SURVEY PROFESSIONAL PAPER 167 PLATE 61

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15

X 2

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67664 32 16

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LOWER TRIASSIC AMMONOIDS

20

X6 21
U. S. GEOLOGICAL SURVEY PROFESSIONAL PAPER 167 PLATE 62

13

I

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17

20 1ft

LOWER TRIASSIC AMMONOIDS
PLATE 62

FIGURES 1-10. Ophiceras spencei Hyatt and Smith (p. 50).

I-4. Side, front, and rear views and septum. (The septa do not show the auxiliary lobes shown by mistake in the drawing.) 

5-7. Side and front views and septum.

8-10. Side, front, and rear views, early adolescent stage; diameter 5.5 millimeters. 

Fiotrniss 11-21. Ophiceras jacksoni Hyatt and Smith (p. 49).

II-13. Side and front views and septum of type specimen.

1.4. Side view.

15. 16. Side view and septum, adult stage.

17, 18. Side view and septum, end of adolescent stage; diameter 25 millimeters.

19-21. Side, front, and rear views, larval stage; diameter 3.2 millimeters.

All specimens figured in this plate from Lower Triassic Columbites zone, 1 mile west of Paris, Idaho. Collection of 

United States National Museum.

 ' ' "". '/ ;..' 175
PLATE 63

FIGURES 1-6. Pseudosageceras multilobatum Noetling (p. 87). 

1, 2. Side and front views. 

4, 5. Side and rear views.

6. Septum of the same specimen. 

FIGURES 7-13. Meekoceras pilatum Hyatt and Smith (p. 59).

7. 8. Side and front views.

9. Septum of the same specimen.

10-12. Side, front, and rear views of a smaller specimen.

13. Septum of the same specimen.

All specimens figured in this plate from Lower Triassic, Columbites zone, 1 mile west of Paris, Idaho. Locality 1981, 

United States Geological Survey.

176
U. S. GEOLOGICAL SURVEY PROFESSIONAL PAPER 167 PLATE 63

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LOWER TRIASSIC AMMONOIDS
U. S. GEOLOGICAL, SURVEY PROFESSIONAL PAPER 167 PLATE 64

13 14

X

15

X6 y fi

LOWER TRIASSIC AMMONOIDS
PLATE 64

FiamiES 1-16. Lecanites (Paralecanites) arnoldi Hyatt and Smith (p. 41). 

1-3. Right side, front, and rear views of. type specimen.

4. Septum of the same specimen.

5. Cross section.

C, 7. Right side and front views, adolescent1 specimen; diameter 15 millimeters.

8. Septum of the same specimen.

9-11. Right side, front, and rear views, adolescent stage; diameter 5 millimeters.

12. Septum of the same specimen.

13-15. Left side, front, and rear views; diameter 3.36 millimeters.

16. Septum of the same specimen. 

FICUKISS 17-22. Flemingites aplanatus (White) (p. 51).

17. 18. Side and front views.

19. Septum of the same specimen.

20. 21. Side and front views, adolescent stage; diameter 14 millimeters. 

22. Septum of the same specimen.

All specimens figured in this plate from Lower Triassic Meekoceras zone, Wood Canyon, Aspen Ridge, 9 miles east of 

Soda Springs, Idaho.

177
PLATE 65

FIGURES 1-5. Ussuria waageni Hyatt and Smith (p. 92).

1. Side view of large specimen, showing the mature septa.

2. Septum of the same specimen.

3. 4. Side and front views of a younger specimen; diameter 75 millimeters. 

5. Septum of the same specimen.

From Lower Triassic Meekoceras zone, Wood Canyon, Aspen Ridge, 9 miles east of Soda Springs, Idaho.

178
U. S. GEOLOGICAL SURVEY PROFESSIONA

LOWER TRIASSIC AMMONOIDS
0. S. GEOLOGICAL SURVEY PROFESSIONAL PAPER 167 PLATE

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LOWER TRIASSIG AMMONOIDS
PLATE 66

FIGURES 1 12. Ussuria waageni Hyatt and Smith (p. 92).

1, 2. Right side and rear views, adolescent stage, showing the early Ussuria stage; diameter 35 millimeters.

3. Septum of the same specimen.

4. 5. Right side and front views, adolescent stage; diameter 30 millimeters.

6. Septum of the same specimen.

7. 8. Side and front views, adolescent stage, showing transition from Thalassoceras to Ussuria; diameter 17 millimeters.

9. Septum of the same specimen.

10. 11. Right side and front views, Thalassoceras stage; diameter 13 millimeters. 

12. Septum of the same specimen.

From Lower Triassic Meekoceras zone, Wood Canyon, Aspen Ridge, 9 miles east of Soda Springs, Idaho.

179
PLATE 67

FIGURES 1, 2. Ussuria waageni Hyatt and Smith (p. 92). Side and front views of a large specimen with the details of the septa

somewhat obliterated by weathering. 

FIGURES 3-7. Hedenstroemia kossmati Hyatt and Smith (p. 78).

3-6. Left side, right side, front, and rear views of the type specimen. 

7. Septum of the same specimen.

All specimens figured in this plate from Lower Triassic Meekoceras zone, Wood Canyon, Aspen Ridge, 9 miles east

of Soda Springs, Idaho. 

180
U. S. GEOLOGICAL SUKVEY PROFESSIONAL PAPER 167 PLATE 67

7 X 2 

LOWER TRIASSIC AMMONOIDS
U. S. GEOLOGICAL SURVEY PROFESSIONAL PAPER 167 PLATE 68

LOWER TRIASSIC AMMONOIDS
PLATE 68

FIGURES 1-10. Cordilleriles angulalus Hyatt and Smith (p. 96).

1-3. Side and front views and septum of a very large specimen; diameter 95 millimeters. 

4-6. Side, front, and septum of a smaller specimen; diameter 80 millimeters.

7. Side view of inner coil, inclosed in the same specimen; diameter about 20 millimeters.

8. 9. Right side and rear views, adolescent stage; diameter 25 millimeters. 

10. Septum of the same specimen.

From Lower Triassic Meekoceras zone, Wood Canyon, Aspen Ridge, 9 miles east of Soda Springs, Idaho.

181
PLATE 69

FIGURES 1-9. Inyoites oiveni Hyatt and Smith (p. 80).

1. Side view of large specimen showing the characteristic sculpture and the septa; diameter 90 millimeters.

2. 3. Side and front views; diameter 72 millimeters.

4-6. Left side, front, and rear views, adolescent specimen; diameter 36 millimeters.

7, 8. Left side and front views, adolescent stage; diameter 27 millimeters.

9. Septum of the same specimen.

From Lower Triassic Meekoceras zone, Oweniles subzone, Union Canyon, 15 miles southeast of Independence, Inyo

County, Calif. 

182
IT. 8. GEOLOGICAL SURVEY PROFESSIONAL PAPER 167 PLATE 69

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67664 32 17 LOWER TRIASSIC AMMONOIDS
U. S. GEOLOGICAL SURVEY PROFESSIONAL PAPER 167 PLATE 70

LOWER TRIASSIC AMMONOIDS
PLATE 70

FIGUKES 1-3. Flemingites russelli Hyatt and Smith (p. 53). 

1, 2. Side and front views.

3. Septum of the same specimen. 

FIGTJHES 4-7. Meekoceras gracilitatis White (p. 57).

4. 5. Side and front views, showing the full length of the body chamber; diameter 77 millimeters. 

6, 7. Side and front views, showing the radial folds; diameter 67 millimeters. 

FLGUKES 8-10. Meekoceras (Koninckites) mushbachanum White (p. 61). 

S, 9. Side and front views (natural size). 

10. Septum of the same specimen.

All specimens figured in this plate from Lower Triassic Meekoceras zone, Wood Canyon, Aspen Ridge, 9 miles east 

of Soda Springs, Idaho.

183
PLATE 71

FIGURES 1-6. Cordilleriles angulatus Hyatt and Smith (p. 96).

1. Larval shell, showing development from Prolecanites to Pronorites stage; diameter 6.5 millimeters.

2. Septum, adolescent stage; diameter 10 millimeters.

3. Septum, adolescent stage; diameter 11 millimeters.

4. Septum; diameter J.2 millimeters.

5. Septum, showing transition to Cordilleriles; diameter 17 millimeters.

6. Adult stage, showing Cordillerites characters.

From Lower Triassic Meekoceras, zone, Wood Canyon, 9 miles east of Soda Springs, Idaho. 

FIGURE 7. Pronorites mixolobus, to show the tripartite first lateral lobe of Pronorites (p. 97). (After De Koninck, Faune du

calcaire carbonifere de la Belgique, pt. 2, p. 122, fig. 1.) 

FIG'URES 8a-h. Pronorites praepermicus Karpinsky, to show the development of the septum up to the Pronorites stage (p. 97).

(After Karpinsky, Ueber die Ammoneen der Artinsk-Stufe, pi. 1, fig. 2, f-n.) 

FIGURE 9. Sicanites mojsvari Gemmellaro, to show the Sicanites stage (p. 97). (After Frech, Fritz, Lethaea geognostica, Teil 1,

Das Palaeozoicum, Band 2, Lief. 3, pi. 59d, fig. 2a.) 

FIGURE 10. Propinacoceras beyrichi Gemmellaro, to show the Propinacoceras stage (p. 97). (After Frech, Fritz, Lethaea

geognostica, Teil 1, Das Palaeozoicum, Band 2, Lief. 3, p. 476, fig. 8.)

184
TJ. S. GEOLOGICAL SURVEY PROFESSIONAL PAPER 167 PLATE 71

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LOWER TRIASSIC AMMONOIDS
U. S. GEOLOGICAL SURVEY PROFESSIONAL PAPER 107 PLATE 72

X 30 X 30 X 30 X 30

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LOWER TRIASSIC AMMONOIDS
PLATE 72

FIGURES 1-24. Columbiles parisianus Hyatt and Smith (p. 107).

1-4. Protoconch and three chambers; diameter 0.50 millimeter. Figure 1 from front, 2 from right side, 3 from below, and 4

from above. 

5, 6. Protoconch and two-thirds of a revolution of the larval shell; diameter 0.75 millimeter. Figure 5 from front, 6 from

right side.

7-9. Left side, front, and rear views, larval stage; diameter 1.50 millimeters. 

10-12. Right side, front, and rear views, larval stage; diameter 1.75 millimeters. 

13-15. Right side, front, and rear views, larval stage; diameter 3 millimeters. 

16-18. Right side, front, and rear views, adolescent stage; diameter 8.50 millimeters. 

19-21. Left side, front, and rear views, adolescent stage; diameter 10 millimeters. 

22-24. Left side, front, and rear views, adolescent stage; diameter 15 millimeters.

From Lower Triassic Columbites zone, 1 mile west of Paris, Idaho. Collection of United States Geological Survey.

185
PLATE 73

FIGURES 1-30. Paranannites aspenensis Hyatt and Smith (p. 98). 

1, 2. Left side and front views of the type specimen.

3. Septum of the same specimen. 

4, 5. Right side and front views of a smaller specimen.

6. Septum of the same specimen with the inner septum drawn from a piece broken off the coil. 

7, 8. Left side and front views; diameter 12 millimeters.

9. Septum of the same specimen. 

10, 11. Right side and front views; diameter 9 millimeters.

12. Septum of the same specimen. 

13-15. Left side, front, and rear views, Nannites stage; diameter 7 millimeters.

16. Septum of the same specimen.

17, 18. Right side and front views, Nannites stage; diameter 5.5 millimeters. 

20, 21. Right side and front views, Nannites stage; diameter 3.88 millimeters.

22. Septum of the same specimen! 

23, 24. Right side and front views, Prondnnites stage; diameter 2.5 millimeters.

25. Septum of the same specimen.

26, 28. Right side, front, and rear views, transition from Parodoceras to Pronannites stage; diameter 1.40 millimeters. 

29, 30. Side and front views, early larval stage showing the latisellate first septum; diameter 0.54 millimeter.

From Lower Triassic Meekoceras zone, Wood Canyon, Aspen Ridge, 9 miles east of Soda Springs, Idaho. Collection 

of United States Geological Survey.

186
U. S. GEOLOGICAL SURVEY PROFESSIONAL PAPER 167 PLATE 73

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LOWER TRIASSIC AMMONOIDS
U. S. GEOLOGICAL SURVEY PBOFESSIONAL PAPEK 167 PLATE 74

21 22 24 25

X5

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LOWER TRIASSIC AMMONOIDS
PLATE 74

FIGURES 1-25. Meekoceras mushbachanum White (p. 61).

1-3. Mature sculpture and septum, corresponding to Arctoceras.

4.. Septum of another specimen.

5. 6. Adolescent stage, showing the nearly smooth compressed whorl.

7. Septum of the same specimen.

8. 9. Adolescent stage; diameter, 31 millimeters.

10. Septum of the same specimen.

11. 12. Adolescent stage; diameter, 25 millimeters.

13. Septum of the same specimen.

14. 15. Adolescent stage; diameter, 20 millimeters.

16, 17. Adolescent stage, showing the siphuncle; diameter, 14 millimeters.

IS. Septum of the same specimen.

19, 20. Adolescent stage showing goniatitic septa; diameter, 10 millimeters.

21. Septum of the same specimen.

22. 23. Adolescent stage; diameter, 6.5 millimeters. 

24, 25. End of larval stage; diameter, 4 millimeters.

Lower Triassic Meekoceras zone, southeastern Idaho, 5 miles southeast of Grays Lake. Shows the transition from 

Meekoceras to Ceratites.

187
PLATE 75

FIGURES 1-6. Meekoceras mushbachanum White (p. 61).

1". Specimen showing the ribs of maturity and the nearly smooth flat inner whorl. 

2, 3. Adolescent inner whorl of the same specimen; diameter, 25 millimeters. 

4-6. Adult stage.

Lower Triassic Meekoceras zone, southeastern Idaho. Collection of United States Geological Survey. Specimens 

shown in Figures 1-3 are from 5 miles southeast of Grays Lake. Those shown in Figures 4-6 are from !}>£ miles 

east of Hot Springs.

188
U. S. GEOLOGICAL SURVEY PROFESSIONAL PAPER 167 PLATE 75

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11 I ^

LOWER TRIASSIC AMMONOIDS
TJ. S. GEOLOGICAL SURVEY PROFESSIO

LOWER TRIASSIC AMMONOIDS
PLATE 76

FIGURES 1-3. Meekoceras mushbachanum White (p. 61).

1. Adult shell, showing the rough sculpture of the mature stage and the smooth, flat, adolescent whorls.

2. 3. Adult shell, showing the sculpture and septa of maturity.

Lower Triassic Meekoceras zone, 5 miles southeast of Grays Lake, Idaho. Shows the transition between Meekoceras 

and Ceraiiles. Collection of United States Geological Survey.

189
PLATE 77 

FIGURES 1-21. Columbites spencei Smith (p. 108).

1-3. Adolescent gastrioceran stage; diameter, 15 millimeters.

4. Septum of the same specimen.

5-7. Adolescent stage; diameter, 11 millimeters.

8. Septum of the same specimen.

9-11. Early adolescent stage; diameter, 9.5 millimeters.

12. Septum of the same specimen.

13-15. Diameter, 7.5 millimeters.

16. Septum of the same specimen.

17. 18. Diameter, 4.5 millimeters.

19. Septum of the same specimen.

20. 21. Diameter, 3 millimeters.

From the Lower Triassic Cohimbites zone in Paris Canyon, \% miles west of Paris, Bear Lake County, Idaho. Collection of United States Geological Survey.

190
U. S. GEOLOGICAL SURVEY PROFESSIONAL PAPER 167 PLATE 77

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67664 32 18

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21

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LOWER TRIASSIG AMMONOIDS
IT. S. GEOLOGICAL SURVEY PEOFES8IONAL PAPER 167 PLATE 78

LOWER TRIASSIC AMMONOIDS
PLATE 78

FIGUKKS 1-16. ColumbiLes spencei Smith (p. 108).

I, 2. Type specimen.

3. Fragment of an adult specimen, showing septa.

4. Septum of the same specimen.

5. 6. Late adolescent stage; diameter 40 millimeters. 

6a. Septum of the same specimen. 

7, 8. Adolescent stage; diameter 31 millimeters. 

9, 10. Adolescent stage; diameter 25 millimeters.

II, 12. Adolescent stage, corresponding to Gastrioceras; diameter 20 millimeters.

13-15. Adolescent stage; diameter 23 millimeters.

16. Septum of the same specimen, drawn at diameter of 15 millimeters.

Lower Triassic Columbites zone, Paris Canyon, lYz miles west of Paris, Bear Lake County, Idaho. Collection of 

United States Geological Survey.

191
PLATE 79

FIGURES 1, 2. Xenodiscus nivalis Diener (p. 44). (After Mathews, op. cit., pi. 1, figs. 1, 4.)

FIGURES 3, 4. Cordillerites compressus Mathews (p. 97). (After Mathews, op. cit., pi. -1, figs. 16, 17.)

FIGURES 5, 6. Xenodiscus rotula Waagen (p. 45). (After Mathews, op. cit., pi. 1, figs. 38, 40.)

FIGURES 7, 8. Meekoceras davisi Mathews. (p. 58). (After Mathews, op. cit., pi. 1, figs. 8, 11.)

FIGURES 9, 10. Anasibirites tenuistriatus (Waagen) (p. 74). (After Mathews, op. cit., pi. 4, figs. 1, 2, " Anasibirites mcdintocki.")

FIGURES 11, 12. Anasibirites hircinus (Waagen) (p. 72). (After Mathews, op. cit., pi. 2, figs. 10, 11, "Anasibirites blackwelderi.")

FIGURES 13-15. Anasibirites angulosus (Waagen) (p. 70). (After Mathews, op. cit., pi. 3, figs. 28, 29, 31, "Anasibirites pseudoibex.")

FIGURES 16, 17. Anasibirites kingianus (Waagen) var, inaequicostatus Waagen (p. 72). (After Mathews, op. cit., pi. 3, figs. 34, 36,

"Anasibirites perrini.")

FIGURE 18. Anasibirites multiformis Welter (p. 74). (After Mathews, op. cit., pi. 4, fig. 24, "Anasibirites romeri.") 

FIGURES 19-21. Anasibirites kingianus (Waagen) (p. 72). (After Mathews, op. cit., pi. 4, figs. 29, 31, 32, "Anasibirites edsoni."} 

FIGURES 22-24. Anasibirites emmonsi Mathews (p. 71). (After Mathews, op. cit., pi. 2, figs. 23, 25, 26, Anasibirites emmonsi.} 

All specimens figured in this plate came from the Anasibirites subzone of the Fort Douglas area, Utah. The figures 

are copied from the paper by A. A. L. Mathews, The Lower Triassic cephalopod fauna of the Fort Douglas area, 

Utah: Walker Mus. Mem., vol. 1, No. 1, 1929. The originals are in The Walker Museum, University of Chicago. 

192
TJ. S. GEOLOGICAL SURVEY PROFESSIONAL PAPER 167 PLATE 79

11

16

17

18

/ f

!

/*;

23

LOWER TRIASSIC AMMONOIDS
TJ. S. GEOLOGICAL SURVEY PROFESSIONAL PAPER 167 PLATE 80

15

LOWER TRIASSIC AMMONOIDS
PLATE 80

FIGURES 1, 2. Anasibirites mojsisovicsi Mathews (p. 73). (After Mathews, op. cit., pi. 5, figs. 2, 3.) 

FIGURES 3-5. Anasibirites bastini Mathews (p. 70). (After Mathews, op. cit., pi. 10, figs. 7, 10, 11.)

FIGURES 6-8. Anasibirites (Goniodiscus) typus Waagen (p. 76). (After Mathews, op. cit.,pi. 5, figs. 22, 26,27, " Goniodiscus americanus.") 

FIGURES 9, 10. Anasibirites (Goniodiscus) utahensis Mathews (p. 77). (After Mathews, op. cit., pi. 6, figs. 29, 30.) 

FIGURES 11, 12. Anasibirites (Goniodiscus) ornatus Mathews (p. 75). (After Mathews, op. cit., pi. 6, figs. 6, 9.) 

FIGURES 13-15. Anasibirites (Goniodiscus) smithi (Mathews) (p. 76). (After Mathews, op. cit., pi. 10, figs. 1, 3, 4, "Gurleyites smithi.") 

All specimens figured in this plate came from the Anasibirites subzone of the Fort Douglas area, Utah. The figures 

are copied from the paper by A. A. L. Mathews, The Lower Triassic cephalopod fauna of the Fort Douglas area, 

Utah: Walker Mus. Mem., vol. 1, No. 1, 1929. The originals are in The Walker Museum, University of Chicago.

193
PLATE 81

FIGURES 1, 2. Kashmirites meeki (Mathews) (p. 67). (After Mathews, op. cit., pi. 8, figs. 12, 14, "Wasalchiles meeki.") 

FIGURES 3-5. Kashmirites wasatchensis Mathews (p. 69). (After Mathews, op. cit., pi. 7, figs. 6, 7, 9, "Kashmirites gilberti.") 

FIGXJKES 6-8. Kashmirites perrini (Mathews) (p. 67). (After Mathews, op. cit., pi. 9, figs. 1, 3, 9, "Wasatchites perrini."') 

FIGURES 9, 10. Kashmirites resseri Mathews (p. 67). (After Mathews, op. cit., pi. 7, figs. 4, 5, Kashmirites resseri.) 

FIGURES 11, 12. Kashmirites seerleyi (Mathews) (p. 68). (After Mathews, op. cit., pi. 8, figs. 8, 9, " Keyserlingites seerleyi.")

All specimens figured on this plate came from the Anasibirites subzone of the Fort Douglas area, Utah. The figures 

are copied from the paper by A. A. L. Mathews, The Lower Triassic cephalopod fauna of the Fort Douglas area 

Utah: Walker Mus. Mem., vol. 1, No. 1, 1929. The originals are in the Walker Museum, University of Chicago

194
U. S. GEOLOGICAL SURVEY PROFESSIONAL PAPER 167 PLATE 81

LOWER TRIASSIC AMMONOIDS
Acknowledgments for aid...........__....... ._..___ ..___ 1,4

Acrocanitos Schindowolf ........__._..______....__-.. 24,25,34, pi. 44

inultilobatiis Schindewolf.......__.__........_____...___ 89, pi.44

Acrochordicoras ____......................._____._.__ 22,26,29,31,32

Adrlanitcs Gonimcllnro.............................. 22, 24, 20, 27, 28, SC, 38, 39, pi. 59

tlinoronsis__...................................._......._...... 24, pi.45

AgaMidcs- . - - - - ---- 23

Agathlccras Gommellaro... .._ ......_. .- -_ ._-- 24, 20,30,38, pi.43

ciscoonso.... -...-........------.-.-.-..-......-...-----.---.....-. 24, pi.43

Agoniatltos.._____-----_-..-.-..___......_._____......_._ 23

Albanltos Arthaber ............._.......____......._..---._ 25,28,35,36

nrbanus Artlmbcr....___.__.......___..................._.... 19,20

osmanicus Artlmbcr......._...........--.....---.-.......-.-.......-.. 20

triadicus Artlmbor....___.....__.........__._...._.__.__ 20

Ambitos Wnagou__......___....................._..........___ 27,28,31

Amphyllites...___.............................................._____ 35

AnahcdonstrooiiiiaHyatt.. . __ _ __. _. _ 77

Annsibiritos Mojsisovics........................ 23, 25, 27, 28, 30, 31, 32,37, 38, 69-70

altonmtus Mnthews..-.......-...-.-----...-.--- .......--.---...-.-. 73

angulostis (Wangen) ...-...-......-------...--- .- 3,0,10,17,70, pi. 79

basslori Mathows,.................................................._... 72

bnstinl Mathews___-----_.............._._. . 3,10, 70-71, pi.80

black welder! Mathews.................................................. 72

brotzi Mathows... ....-...-.-.-....- ........ ....-.-....--.--. 75

coratitoides (Waagen)..........._........... ....................... 17

dark! Mathews..... -.............-.-.-...-..-..-.-.......---..----.. 74

crickmayi M.'athcws.....-......--.__ . . 71

dcsortorum Smith, n. sp...... 2,6, 9,10,46,48,49, 50, 58, 62, 71, 80,103, pis. 52, 56

dioncri Mathews....-.--..-..-...-..-.---.-.---._..._...--..--:__. 74

oclsoni Mathows_. --.. ..:----- __ --- 72

emmonsi Mathows..--.....--.-.-.-...-----..--------.-.--.---- 3,10, 71, pi. 79

flsheri Miathows._--------------_.-.--.-..-...-.........-.-.._.-.. 74

gayi Mathews. . ______........ . ....__.__ . 75

gibsoni Mathows... .__....._.......... ..........._____ 73

hirciiius (Waagon).......... ... ..- ...-.. ........ 3,10,17,72, pi. 79

hyatti M'athows........... _.-...--...-------.......---. ..... 74

ibex Waagon--------.. 7,17,73

inaociuicostatus Waagon......---...------------.----.-.....----.--.----- 17,72

johannsoni Mathews.................................................... 74

kotchami Mathews ........-...--.----.------.-----......---. .. 74

kingianus (Waagen) 3, 6,10,17, 73, pi. 79

kiiigiaiuis (Waagen) var. inaeciuicostatus Waagen.......... 3,10, 72-73, pi. 79

lindgroni Smith, n.sp.____________.__.__... 2,7,9,10,17, 73, pi. 53 

madisoni Mathews__..._-.-....-..--.-.......----.-...--_..--. 73, pi. 79

mcclintocki M!athews._._. - ---.- -- __. .... 74,75

mojsisovicsi Miathows ... . 3,10,73, pi.80

rnultiforrnis Welter 3,7,10,71,72,73-74, 76, pi. 79

inultiformis Welter var. hyatti Mathews.......__....._.-.---.-.- 3,10,74

nootlingi Hyattand Smith......-.-.....--...--. 2,46,49, 50, 73, 74, 90,103, pi. 9

ornatus Mathows_-.--............---.--.-....----.__...... 75-76, pi. 80

porrini Mathows........__.__._.....I .........- ..... 72

psoudoibox Mathows.... ...........-------------------..---.-.-----.- 70

rollini Mathews......_____............----....--..._..-.--..---... 75

romeri Mathows_.. _ _______ __-- ._ _ _.. . __ 73

Salisbury! Mathows....-.-.---.......-.-.-..------..-......----.-.. .. 74

smithi (Mathews). .................. 75, 76, pi. 80

spinigor KrafTt.... ... .._. . . .... . ..... 17

tonuistriatus (Waagon)._......._.....______ 3,0,10,71, 74-75, pi. 79

typus (Waagon). .................-. ...... 75, 76-77, pi. 31

utahonsis Mathows....._._.......... __.___ .. 75, 77, pi. 80 j

vanbuskirki Mathows . _.___-.- - - -- _.. --- _. 71 

varians Mathows..-.---.I... ..-.-.-.--. .......................... 77

voranus Mathows- -_--_--.......----------- -. . - -- 74

ward! Mathews... --...-.-.......--.-.-.------.- .-.-.-.-..---.---- 74

woavori Mathews......._ . _ ----------------_.-..-....---...-- 74

wollori Mathows........__---.....--..--.-__.._......---..-.-.---. 71

Anasibirites subzono, characteristic species and general character of fauna of.. 17 

geographic distribution of......._......... _ . -. - -- - 13

Anolcitos ........._ _ .._.. _ --- . _- - 23,33

Aphyllites.. -- 22, 23, 25, 27, pi. 60

inarcellonsis Hall... . .... . _ 23

Arcostos .... .............. 27,36,39

cirratns White__. .- -. - - - ..... 53

paciflous Hyatt and Smith._ _ . 22, pi. 59 

trask.i Hyalt and Smith .. 22, pi. 59

Page 

Arcestidae _ . ._ _ .. . 38-39

Arcostoidea..... --_____ _ __ ._ _.__ 38-39,97-103

ArctocerasHyatt._____......._____...__.___.........._..._ 31,54

Arnautoceltites Diener................................................... 26, 29, 37

arnauticus Arthaber_.................................................. 20

Arpadites Mojsisovics..__...._............................_...._.... 27,32

gabbi Hyattand Smith.....__.__.....__.._______.___._ pi. 59

Arthaberites Diener- -.-.........----....._........................... 35

Artinskia Karpinsky.. ..............._................................. 36

Aspenites Hyatt and Smith.................... 21, 22, 23, 24, 25, 28, 34, 85-86, pi. CO

acutus Hyatt and Smith............. ___._._ passim 2-111, 86, pis. 2, 3, 30. 60

laevis Welter....... .................................... 2, 7,8,16, 86, pi. 28

layeriformis Welter _ _--...-.__. 86

obtusus Smith, n. sp. _.. . 2,8, 86-67, pi. 31 

Aspidites Waagen.............................................. 31, 60, 02, 63, 79,101

eurasiaticus Frech. --......--.----..-.-..........-.._......____ 64

hooveri Hyatt and Smith _.....---....-.--.._....................... 63

muthianus Krafft.....- _.. __--- ----_____. ____.______ __ 64

superbus Waagen....................................................... 63

B

Balatonites__..-...-....-..,.......-----.....---.....----.................. 33

Bambanagites__._....___________.__-...__..__..-....-.._ 35

Beatites Arthaber........................................................... 27, 28

Beloceras Hyatt . ---....... 22, 23, 24, 25, 26, 27, 29, 34, pi. 60

multilobatum Beyrich...___..__.---.--..--._______.... 24, pi. 44

Beloceratoidea, phylogenetic classification of .. .--...-------.----.--.- 34

Beneckeia Mojsisovics-------.-.--...-.----.-..----.-..------.-.----..---.-.- 28

Beyrichites Waagen... -_._......_-...-_ ...--..---_ .-.--.....- 23,31,32

rotelliformis White...._...__.______._.____.______ 27, pi.59

Bibliography.......----------.......---.-....----..............-...........- 4-6

Brancoceras__.--..----.--...-_...__----------_................... 23

California, Meekoceras zone of, general features of...-.---.---.--.....--.-.-- 9

California, Owenites fauna of.....__.._----...--.-..-.--..-.--...-.-.-- 2-3

Carnites.....--.-------.--_................................................. 34,35

noridus................ 27

Celtites Mojsisovics--..---.-....-.-..---..-..-- 22, 24, 26, 27, 29, 30, 36, 37,103-104

apostolicus Smith, n. sp.__...___- ..-_._..__-.... 3,11,37,104, pi. 48

armatus Waagen. -.--........------.---.-...-.---.--....-...-----.--- 66

arnauticus Arthaber __ __ .. ._ ---. _ - ...... 37

floriani Mojsisovics.-----.-.--.-.-----_----..-....---.....---.-.-...--- 84

fortis . 15,37

lidacensis - -------...---....--.----...---...-------..---..--. 15

planorbis Smith..._................................................... 20

planovolvis Smith, n.sp... ... ..---...--- 3,11,27,37,104, pi. 48 

polygyratus Smith..-...........--.-.....-......--.-... ........ 104

radiosus. _--- ------.- _ ..---.--...-----.-. 15,37

ursensis Smith, n. sp.................. 3,11,20,27,37,49,59,88,104-105, pi. 47

Celtitidae.. __.......----..._ 36-37,103

Ceratites De Haan..._ ....___.___. ...... __.. _........ 22,23,30,31,32

binodosus, zone of. -------.. -. _............................. 18

carbonarius... .. ..__-. ------ ,- ----- ..---- _.. 43

decrescens Hauer_..__....__...__..__.-..-...--..-. ___ 39,103

flemingianus De Koninck._._ .. __. . _ __. . __ 51

glaucus Muenster.------_-....--...-.-----.---.---...-.-.-.----....--. 40

haguei Smith.__ ...__......--...-..-.....--- ..----......--.-.. 33

humboldtensis Hyatt and Smith--- --- --_--...._-.--. 32

idrianus Hauer________...-...--.-------..-.-.-.-.---.-.---...--. 83

lawrencianus De Koninck......_- . ._.._..---.....-...... 101

nodosus ----------- ----...----.--.--....--. .... ----.-.--.--- 82

robustus Mojsisovics...-.........---......--...-----,..----......-...... 68

subrobustus Mojsisovics-_....--... -----..----.-.-......-......--... 67

trinodosus, zone of.--................................................... 18

Ceratitidae.---.-------------------.--------------------.-.----------- 31-32,82-83

Ceratitoidea.______.___...__.___.____________.__ 30 

Clionites....-.-.------------..-----.-------------....-.---...--...-..----... 23,33

Clypeoceras Smith----...-....--....-..-.............-..---.-- 25,27,28,31,62-63

brouweri Smith............____._................_._....__.. 15

hooveri Hyatt and Smith..________....__.....__ 2,9,63-64, pi. 17

muthianum (KrafEt).__................................. 2,6,8,16,64, pi. 27

pusillum Smith, n. sp..__________.__________ 2,9,64-65, pi. 51 

spitiense Krafft.- _._.. .._ . .. 15

195
196 INDEX

Page, 

Clypites Waagen.--.._ .- -.-_..__ _. .- ____ 79

tenuis Hyatt and Smith........................................_.- 79, pi. 1

typicus Waagen-.-.-__-------------------------__ _ .. .... 79

Columbites Hyatt and Smith..--------- ....... 21,22,24,26,27,29,36,37,105-106

consanguineus Smith, n. sp__._________________ 3, 11, 106, pi. 46 

dusmani Arthaber__.-.----.-.........-...._.._.._..1.._..._ 7,106

europaeus Arthaber.--------------------------------_.-.--.__---- 7, 20,106

humboldtensis Smith__.---.....---.--..........-.__..___.._- 106

ligatus Smith, n. sp.____.____...__________x_ 3, 7, 11, 106, pi. 47 

minimus Smith, n. sp..--..-.....--.-...-...----...-... 3, 11, 106-107, pi. 47

mirditensis Arthaber._________-------___________.:__ 20,106

ornatus Smith, n. sp.___-__.____._________ 3, 11, 106, 107, pi. 46 

parisianus Hyatt and Smith._....__ passim 3-108, 107-108, pis. 1, 61, 72

perrini-smithi............................._______....__.......... 106

plicatulus Smith.............._-----------____------_---------- 106

spencei Smith________...._____.___ passim 3-108, 1O8, pis. 77, 78

sp. indet---.________:._ ___ _ _ ______........_____ 7

Columbites zone, characteristic species of -'.----...--...-_L............... 20

general character of fauna of.___...................................... 18-19

geographic distribution of._-------------.----.-----............_...... 13

Cordillerites Hyatt and Smith............... 21, 22, 23, 24, 25, 28, 36, 95-96, pi. 60

angulatus Hyatt and Smith_____ passim 2-111, 96-97, pis. 2, 42, 60, 68, 71 

compressus Mathews______-.-.-......-._...__...... 3, 10, 97, pi. 79

Correlation table of Lower Triassic faunas_----------------_.._-------- 34

Cosmacanthus elegans Evans__..-_-.--.-.--.-.----..-------.----.-----. 11

Cuccoceras Diener__...................................................... 31

Cyclolobidae.______.__......____..______..-----....--..-_ 97-98

Cyclolobus____._______.--......---.__-_-___-__.--.....---._ 26,38

Cyrtopleurites__.......................................................... 35

Czekanowskites, Diener___--.-._--..----......_--------.....-.-.-.--- 28

D 

Dagnoceras Arthaber______.-__---------------_........_. 25, 28, 31, 65

bonnevillense Smith, n. sp.------------------------------------ 2, 8, 65, pi. 29

bridges! Smith, n. sp_______..__.__....__....__... 2, 8, 65, pi. 31

haydeni Smith, n. sp.___-----------__..__......__ 2, 8, 65, 66, pi. 29

komanum Arthaber....................................._.._..._.. 65

pealei Smith, n. sp._____.........___.......__... 2, 8, 27, 65, 66, pi. 29

terbunicum Arthaber ._.............................................. 65, 66

Dalmatites Kittl. -.-......... ............................... 25, 28, 34, 80-81

attenuates Smith, n. sp........................ 3, 7, 10, 11, 18, 81, 83, 84, pi. 57

minutus Smith______.__..___._____._______._.___________ _...._____ 81

morlaccus Kittl..________._______..__.__.____ 7,18,80,81 

parvtis Smith...___._____....__.__.____._____ 27, 81, pi. 60

richardsi Smith, n. sp.........._.............................._... 2, 8, 81

Dauubites Mojsisovics_________.___.____....____.. 28, 32, 42, 84-85

nivalis Diener-___.--_-._......_------------------------___.. 44

strong! Hyatt and Smith......----__............................ 3, 85, pi. 9

whiteanus Waagen.___..........................................._ 46

Daraelites Oemmellaro_________..__...._____.. 21, 23, 24, 25, 27, 33, 35, 36

Diener, Carl, quoted.-.---__.._-.-.--.--------.----...---.__-------- 68

Dieneria arthaberi Hyatt and Smith.._................................... pi. 60

Dimorphoceras.--.-------_...._............................. 23, 25, 26, 27, 34, 35

atratum Ooldfuss___.--_-.__..............................__ 92

gilbertsoni Phillips.____________.__.._____.......__ 92, pi. 42

Dimorphoceratoidea, phylogenetic classification o(.......-......'-.-.......-.. 35

Dinarites Mojsisovics.......__..__.................................... 28,32

dalmatinus Hauer..___.._.---------............................... 18

muchianus Mojsisovics-----------_.................................... 18

Discophyllites__.-.-..-._....----............................._.......... 33

patens... .. ______..__________............_____ 27, pi. 60

Discotropites..---__-..------.-----.................'.......-.--.... ....... 34

mojsvarensis Smith......._____.__.__..___...._.____ 22, pi. 58

sandlingensis Hauer....-__.______...............__ 22, 27,37,105, pi. 58

Doricranites Hyatt.....................................^.............._... 28

Durgaites Diener..__..___._....__.___.__.........__.___ 28,32

E 

Epiceltites Arthaber..-.______.__._.__...._._.__....... 28,31,37

Episageceras Noetling...................^................................. 25,28,36

dalailamae Diener_--.---.----.-..----..---......................-...... 15

Eutornoceras__---.-.---.--.-.--.........---................,......--..... 34

laubei---------__................................................... 27, pi. 60

F

Fauna, Lower Triassic amrnonoid, general features of...-------.----.----.... 6

Faunal zones, general features of Lower Triassic.-..---._--------_-_.---.-- 7-11

Flemingites Waagen______...._______________ 22, 25, 28, 30, 31,33, 51

aplanatus (White)......-.. ..--........ passim 1-111, 51-53, pis. 11,22,39,64

aspenensis Smith n. sp_........................___...... 1, 8, 51, 52, pi. 23

bannockensis Smith, n. sp__.___-__.._______ 1,8,51,52-53, pi. 23 

cirratus (White)... . .--.-..-.................. passim 1-111, 53, pis. 20, 26

compressus (White)_................................__.._......... 16

flemingianus De Koninck............................................... 53

rohilla Diener.._______...................__--------__ 6,15,16,51-52

Page

Flemingites russelli Hyatt and Smith._____._ passim 2-111, 53, pis. 1,26,70 

russelli Hyatt and Smith var. gracilis Smith, n. var__ 2,8, 53-54, pi. 23 

salya Diener___..._____---..---.---------------------.--.----.... 6, 53

Flemingites beds, correlation of_.--------------------------------.......-. 15

Florianites Hyatt....._.............................._.---.---.......... 84

Frechites Smith, n. gen__................................................. 32

Fremontites Smith.................................................._.. 23, 24,35

ashleyi Hyatt and Smith_._..........___.______......._ 27,90, pi. 60

Gastrioceras Hyatt.. ............................................ 24,26,27,36,37,38

branneri __ ---------------------------------------.---.-.-. _ ..... _ . 24

globulosum...- ______ . _ --. _ . _ ------ _______________ 38, 109

listeri... ..-.---...-------.--.-..--.------.-..---.-..-----..--.-. 22,24,37, pi. 43

welleri __ .... _____ . _ ... _ . __ . __________ . ____ 24, pi. 43

zitteli. .-.'---..--- ----.--.----------......-.-.---......--. .... 24, pi. 45

Gastrioceratea.--.--------- __ .. ______ ... _ . _____ ..... _ .. 36-39,97-111

Genodiscus Smith.--.. _ ... __ ... _____ . _______ . __ ... 23, 25, 28, 30, 32 

lidacensis Welter.---------.--------------.-.---.----.--------.-..------. 15

radiosus Krafft.. ------ __ -.---------------.----------.--...-..---. _ 15

Genodiscus zone, general character of fauna of---.--.------------------------ 15

geographic distribution of... ..--------.----.----.-...-...--------------. 13

Gephyroceras... _______ .. __ .. ____ . _ . ___ ..... ____ 23,24,25,27,29 

regale. - ____ -------- __ - _ . _ . _ . ____ .. _ . _ 23, pi. 44

uchtense Holzapfel. ---..-----.-.----.-----.--..-------------------- _ .. 40

Gephyroceratea... _ .... _______ ------- _ - _ .... ___ ..' . _ 29-36,39-96

"airtyites".. - - -- 24

Glyphioceras ________ . ____ ---------- _ ------- ____ . _ .. ____ 21, 26

Goniatite stages, recapitulation of --------.-_-----.-_------------------------ 27

Goniodiscus Waagen.... ______ ........ __ . ___ . ____ ----- 28,31, 75-77

1 americanus Mathows.. --...-----...----.-------------.-...-....----.-.-- 76

beyrichi.. _ . ____ . __ ........ _ ... __ . __ . _ . ____ ..--. 27

ornatus Mathews. ...... --.----.--.--.----.---...--..---- 3, 10, 75-76, pi. 80

shumardi Mathews __ .-------..-.--..-.-----'---.--..-.-.-- _ ... .. 76

slocumi Mathews. -------------------- -- --^- ------------- _ .. _ -.... 76

smithi (Mathews)-..-.-..----..-.-.--.-..-.----.- - .-. 3, 10, 76, pi. 80

typus Waagen...-.----..--.-..-.---..--.--.--.-- 2, 3, 7, 10, 17, 75, 76-77, pi. 80

utahensis Mathews. _ .--..- . _____ .. _________ 3, 10, 77, pi. 80 

(?) varians Mathews..--- -------------- ____ - ________ ----- 77

walcottiMathews. ---------------- _ -------.----...---.---------------- 76

Gonioloboceras _____ . _ ---------------------------------- ----- .. 23

welleri Smith.... - 23, 24, pi. 43

Gurleyites bastini Mathews.--- - 70

smithi Mathews __ _-. - - --- 76

Gymnites. 30,33,39

Gymnitidae.--.-----.------- ------------------------------------------------ 33

GymnotocerasHyatt - .. - 23,31,32,35

blakei Gabb 27, pi. 59

Gyronites frequens Waagen. .......... ...............................^...... 52

mojsisovicsi Waagen __ ....___----------------_------.----------.----.- 66

nangaensis Waagen __ -----------.----.-.--...-----------.---.---------- 52

radians Waagen. .... -------------------------------------- ------ 45

rotula Waagen. ------------.----__-.------------------------ ---. -. 45

whiteanus Waagen.. .. _ ..........-..---------------------------------- 52

H 

HaliluciteS-. ---------------------------------------------------------------- 34

. Halorites... 36,38

Haloritidae - , -- - -- - - 38,108

Hanielites Welter.. . 28

Harpoceras.--------------- ----------------------------- .-..----. .. 81

Hauerites Mojsisovics-- _ .----.-------. -.---. ------------- -. 35

Haueritidae.----------- _ -------- _ -----.--.-..----- ..- -- 35,89

Haydenites Diener.- _ ___ __._ ......... ------ ... ..-. .- 32

Hedenstroemia Waagen... - - -.-- - -- 28,30,31,34, 77-78 

hyatti Smith, n. sp..... 2, 8, 78, pi. 27

kasliuensis Haniel. ... ..........----------- ... ....- 16

kastriotae Arthaber.. ------------------------------ .-... . 20

kossmati Hyatt and Smith passim 2-111, 78-79, pis. 28,41,67

lilangensis Krafft _____ . __ .... __ - _ .. . . - - 15

mojsisovicsi Diener _ _-----------------_-------------.-------------- 7, 16, 78

tenuis Hyatt and Smith.......-------....------.----------------.- 2, 79, pi. 1

Hedenstroemia fauna, correlation of-.------------------------ ... ... 15

Hemiprionites Spath..-.. ........................ .. ._ -------- 75

Hoffmannia Gemmellaro-.-.------------ --- ----- ---------------- 26,36, 38

Hollandites Diener .-.--- ----------------------------- 23, 31, 32

organi Smith-.. 27, pi. 59

Hololobus Kittl.. 27

Homerites Mojsisovics...------------- -------------------------------- -- 38

Homoceras- ------------------ __ -.--_--. -- - - - 26

Hungarites Mojsisovics _ ......--.----...------.. __ __ -.---..- 25, 28, 34

Hungaritidae - - 34,79-80

Hyatt, Alpheus, and Smith, J. P., cited. __ . _ - ______ - ----- 32

H-yattbceras. --------- ... ___-_- - -.----.-.-.----------------- 26
INDEX 197

I Pnge

"Iborglcoras ".._~___....-__.--.-..____..........._.............. 35

Idaho, Columbitos fauna of _______.___._..._____._..... 3

Oolumbitos zone of, general features and fauna of.........---..-.-.--..-- 11

Mookocoras zone of, fauna of.......---...--......-......----............ 1-2

general features of...--.......-..------.-.-.-........ ..--.-----.-.-. 7-8

Owonitos stibzono of, fauna of.-..-.-........-...-.......-------.-------- 10

Psoudosagccoras multilobatum subzono of, fauna of_................... S

general features of ....._. _.__.-,- -. .__. . .. .. -. 7-8

Tirolitos fauna of...-.........----.--..-................................. 3

Tirolitos zone of, general features of__.................................. 10-11

Iniitoccras.................................................................. 23

Inyo County, Calif., Owenites subzono of, fauna of...-...................... 9

Inyoitcs Hyatt and Smith . . .. ... 25, 28, 80

disooidalis Welter..................................................... 7,16,80

kashmiricus Dioncr..--..........-.-.-.-------........_..__........ 16,80

owonl Hyatt and Smith.. .___.__.___.__._. ..passim 3-103, 80, pis. 6, 40, 69 

Isculitcs.- .-..................---...-....-J-- 24, 26, 29, 37, 38, 111

originis Artliabor..........................................._--------- 20, 111

stoliczkai Smith....._...-.-...-..-..........----......---.-.........-. 20

Japonitos Mojsisovics. 

Joannitos__..........

................................................. 28

.-. 38

Juvavitos____._.__._____.....__-.....--..__ 22,24,27,36,38, pi. 58 

subintcrinittons Hyatt and Smith___........___.________ 22, pi. 58

JuvonitosSmith................................................26, 27, 38,108-109

dionori Hyatt and Smith................. 2, 3. 7, 8, 9,10, 62, 87, 90,109, pis. 7, 32

horberti Dioncr.....................................__............... 7,109

(?) hindostfums Dioncr.................._-.--.._...._.--..._... 109

krafTti Smith........................ 2,8,10,27,44,65,66,87,108,109, 111, pi. 21

mod ins Krftfft..................................._..................... 7

sanctorum Smith, n.'sp_____....__......__...--..-_ 2, 7, 8,110, pi. 31

soptontrionalis Smith, n. sp_................................ 2,8,110, pi. 31

Kashmiritcs Dioncr..._____......_.__._......... 25, 28, 31, 32, 37, 66-67

acutangulatus AVeltcr...__....._...__.__.........__...___ 69

armatus Waagon........................................................ 16, 68

blasehkci......___.................................................. 68

donsistriat;is Welter_........-.--...............-......-......------... 16

gilbert! Miathows ..__................................................ 69

meoki (Mathows) ..___._.-...__................__ 3,10,67, pi. 81

' pcrrini (Mathows)_________.....__................... 3, 10, 67, pi. 81

rossori MiUhows___.__...........__..-.___...... 3,10,67-68, pi. 81

socrloyi (Mathows)...----................................... 3,10,68, pi. 81

subarmatus Dioncr......-.................'.................. 3,7,10,16,68, 69

thornoi Mathcws........................................................ 69

wasatchonsis Mathows___.__.__.........._....._ 3,7,10,69, pi. 81

Kollnoritos Arthabor.....___............__..........__......_____ 32.33

Koysorllngitos Hyatt____.____.-.-...-.-.-I---__..............__ 28,32

soerloyi Mathows__.......-.-.........................---....'......... 68

subrobustus Mojsisovics....___...._...._......___--------_ 20

Klnrnathitcs Smith.._________.............__...................._ 35

Koninckitos Waagen.__................................................ 60-62

ovansi Smith, n. sp... ..___............____..... 60-61, pis. 35,36

mushbachamim White.-.................. 61, pis. 15,16,18, 38, 59, 70, 74, 75, 76

inushbaehanuin White, var. corrugatum Smith, n. var......--_..- 61, pi. 38

nowberryi Smith, n. sp....______..........__.___......... 62, pi. 53

strong! Smith, n. sp....-___._.__......___.......__....... 62, pi. 52

tiiborculatiim Smith, n. sp..__..__......___................ 62, pi. 50

votustus Waogon._____..._....__........__................_ 60, 61

Kymatitcs Waagon___................................................. 27,28,31

L

Lanccolites Hyatt and Smith.................................... 23,24,25,28,35,89

bicarimvtus Smith, n.sp .__......___ 3,9,10,27,44,46,48,49,50,90, pi. 55

coinpactus Hyatt'and'Smith_______. passim 2-111, 90, pis. 4, 5, 21, 28,40, 60

Lccanitos Mojsisovics..................... 22, 23, 25, 26, 27, 28,30, 31, 32, 33, 34, 39, 40

arnoldi Hyatt and Smith.......................... 1, 2,8, 9, 41, pis. 28, 39, 59, 64

gangotieus Do Koninck................_..____.___._____... 42

glancus Muonstor....................................................... 42

kncchti Hyatt and Smith............................ 1,2,8,9,41-42, pis.9,28

vogdesi..... .... ........_.....__........____...__.. 40

Lccontciceras Smith_...................................................... 38

cnlifornicum ......................................................... 27

Loiophyllites Dioner___..__......................................... 25,28,30

diencri Arthabor..................................................... 19, 20,33

harn Dioner......__................................................... 20

king! Dienor....___._..._..........._........___.-.-... 19,20,27,33

pitamalm Dicncr_............................................... 19,20,27,33

pradyumna_______................................................. 20

Longobarditcs M'ojsisovics...._______..........__._............:.: 34

novadaniis.. ___ ..._______._________...._...-27, pi. 60

Lower Triussic genera of ammonites, geographic distribution of..------------ 28-29

Page

Lower Triassic interregional correlation zones, geographic distribution of..-.. 13-14 

historical summary of..........-.....--------.......-------...--------.. 11-13

Lytoceras..---.--....-..-...-....--.......-------.....-.-.------.-..------.- 30,33

M 

Marathonites. - - 21,22, 24, 26; 27,36,38, pi. 59

ganti. . . -.- __. . - 24, pi. 43

Margarites. _..__.................................................... 38

Mathews, A. A. L., quoted................. 58, 67, 68, 69, 70, 71, 72, 73, 74,-75, 76, 77,97

Medlicottia Waagen........................ ......... 21, 22, 23, 24, 25, 27,34, 35, 36

noetlingi Haniel.._--.-..---.......-----.-.--.......------.-.- --.... 17

Meekoceras Hyatt.._............................ 21,25,28,30,31,32,34,36,54-56

amne Mojsisovics--.-..-------.-....--------------.-.-------.-- ------ 7

aplanatum White......---------------------------------------------- 46, 51, 55

nrthaberi Smith, n.sp..-. .-...-... --.. . .-- 2,6,8,9,56, pi. 32 

.boreale Diener___-.------....-......----.......-....-----.-.. -.. '6, 57, 59

costatum Oeberg....._....---.-......-.---.....---..----..-...--- .. 61

cristatum Smith, n. sp....................................... 2,8, 56, pis. 33, 34

curticostatum Smith, n. sp...---.-..----.---.-... 3,11, 56, 58, 59,106, pi. 48

davisi Mathews -- ---- ..-------------------------- 3,10, 58, pi. 79

disciforme Krafft and Diener...___.._.._....._________---_.------.-.._-- 60

discoides Waagen__.............---.................---.----.-.-.-.--- 15

elkoense Smith......-- .-.----...--...---..........-.... 2, 56-57, 59, pi. 55

evansi Smith, n. sp.---..-...........- --- .-- 2,8,60-61, pis. 35,36

fulguratum Waagen.------.--.---.......---...-------.---------.- -.-- 6

furcatum M^ojsisovics---.-----.-_...-----..-------_------------------ 78

gracilitatis AVhite passim 2-111,57, pis. 12,13,14,36,37,38,70

hertleini Mathews_------------------_-...-.._.._---._ ------ - 58

hodgsoni Diener___-----------....---...--.._---------_-...-..--- 60

jolinkense Kraflt...___----------____._.__-----__..__..- 16

keyserlingi Mojsisovics.- -----.. - ---. ------ 7, 58

lindstroemi Mojsisovics----...----.-----.----...--...---------- ------- 17

malayicum Welter___----------------------.-.._..--- -------- 76

marginale Arthaber.-________.__.. ..__... ..... 7

markhami Dieuer.____-------....---_.__.........--....-----.... 15

micromphalus Smith, n. sp.______.________ 3,7,11,58, 59,106, pi. 49 

mushbachamim White.--..-, passim 2-111, 61, pis. 15,16,18, 38, 59,70,74, 75, 76 

mushbachanum White var. corrugatum Smith, n. var.- .. 2,8, 61-62, pi. 38 

newberryi Smith, n.sp.. ......... ......-'..........------_ 2,9,62, pi. 53

patelliforme Smith, n. sp...---------......... -... . 2,8,58, pis. 28,52

pilatum Hyatt and Smith-----.--.....--- 3, 7,11,49, 50, 58, 59, 84,88,106, pi. 63

polare M'ojsisovics_-_------------------------------ '.--.......... 17

radiosum Waagen....__...._______....._____ 2,6,9,16,57,59, pi. 51

rotundatum Mojsisovios_-...--....---------------.-----------...------ 7

sanctorum Smith, n. sp ..---....-------- -.-. 2, 3, 7,11, 20, 58, 59, pi. 49

sibiricum Mojsisovics--.-.-------------------..-.---------- ----------. 20

strongi Smith, n. sp - - - 2, 62, pi. 52

sylvanum Smith, n. sp .. ..-.-... ............ 2,8,44,56,59-60, pi. 33

tuberculatum Smith, n. sp_.__...__-----_____..._- 2,6,9,62, pi. 50

vercheri Waagen-...-.-- . -.--........----..........------..--... 60

waageni Hyatt and Smith_____.____ _._....______ ._____ --. . 46

yudisthira Diener....___________-.-._____ ... - 16

Meekoceras zone, general character of fauna of.- _ _ .__.-- ----- .--. 15-17

subdivisions of.-----------____...---.---........-.-----.-----------. 13

Meekoceratidae..----------_----__ _ _-.- .-_ -.--.. ---------- 31,54

Metacarnites...__.--.-..__..____... _ ___._- -- --.--. 35

M^etasibirites Mojsisovics___-----.....- -.-.------ ..-..----------.--. 27,38

frechi Hyatt and Smith._.___._____...-_.__.__.....__ pi. 58

Monophyllites._____-__._______._.._.._..-..--.-- 33

N 

Nannites Mojsisovics_-_...------.....----..-...-.---..-------------. 26,27,39

dieneri Hyatt and Smith.......-.-_........--.-----..--........---. 109

herberti Diener. _. __....... .... 109

hindostanus Diener:_____.-._______..___._____..._ 109,110 

medius Krafft- ..-- . -- --- - 109

Nannitinae ---..-.... . ____.--.._-._. ..-.-...-..------..... 98

Nautilus (Pleuronautilus) sp. indet _------------ ------- -.... 11

Nautilus sp. indet_..---__------ _____---_ -_-- --- 11

Neodimorphoceras Schmidt--.-----.-.....--------.------.------------ 23,24,25,35

texanurn Smith.__________________.--._________ 23, pi. 43 

Nevada, Owenites fauna of........---.....---- ........... ..--- .... 2-3

Nevadites- , - 23,33

merriami__..........-----------.....--..-.-._ - --- 27, pi. 59

?Nomismoceras Hyatt___.---------...._-..._.......------.....------- 26,33

0

Olenekites Hyatt .. 28,32

spiniplicatus Mlojsiso vies------------------------------------- --__ 20

Ophiceras driesbach......... .-- .-. --.- ...-... 22,25,28,30,31,32,48

aplanatum Frech___.............--------...-.---------...-..-----.. 51

demissum Oppel.. ---------- ---.-- -------- - - -- ----- 6,15,49

dieneri Hyatt and Smith. 1,6,8,27,48-49, 66, pi. 8

himalayanum Griesbach....-----,-..................................... 48
198 INDEX

Page 

Ophiceras involutum Smith.____.__ _ __ __._ __ -- .- 9

jacksoni Hyatt and Smith..........------.--. 3, 7,11, 27, 49,50, 56, 59,88, pi. 62

matheri Mathevvs.-------------------------------------------------------- 45

parvum Smith, n. sp._------------------------------------ 2,9,49, 50, pi. 54

ptychodes Diener..-------------------------------- ----------------- 50

sakuntala Diener -________-------___._____ 2,6,9,15,50, pis. 54, 56

spencei Hyatt and Smith..-..... .... 3, 7,11,49, 50, 56, 59,84,86,107, pi. 62

subquadratum Smith, n. sp_ - - 2,9,49, 50, pi. 54

tibeticum Griesbach_-------_. _---.-._----------------.--------- 15,48

Orthoceras sp. indet__----------------.----.-------...---------- ------- 11

Otoceras Griesbach... 25,28,34

woodwardi Griesbach...-_ - - - - - 15

Otoceras zone, general character of fauna of- ---- - 15

geographic distribution of--- - - 13

Owenites Hyatt and Smith.. 29,39,99-100

carpenteri Smith, n. sp -_-_____-----__ _______ 3,9,100, pi. 54

egrediens Welter....-_ .- 3, 7,16, 64,100, pi. 52

koeneni Hyatt and Smith...-.-____.__.. passim 3-103,100-101, pi. 10 

simplex Welter______--------------------------------____.... 16

zitteli Smith, n. sp.____________ .-..._________ 3, 9,101, pi. 52

Owenites subzone, characteristic species of ------------------ 16

geographic distribution of-.- ,. - - .. 13

P 

Palaeophyllites? --------------------------------------------------------- 28

Paraceltites Gemmellaro..._-__ __. __.__...._ 25,27,28,30,36,37

elegans Gemmellaro----------------------------------------------------- 27,41

multicostatus B5se.--------------------------------------------_ 27,41, pi. 44

Paraceratites Hyatt.-------------------------------------------------------- 23,32

Paragastrioceras Tchernow..._.. _. 22,24,26,29,36,37

Parakymatites-..-..___ _ --- -... ... ------ 31

Paralecanites Diener...-.----------------- 21, 22, 25, 26, 27, 28, 30, 31, 39, 40-43

arnoldi Hyatt and Smith . _ 27, 41, pis. 28,39, 59, 64

knechti Hyatt and Smith.---------__ _____-____ 41-43, pis. 9,28

sextensis Diener. - 41

Paralegoceras Hyatt ---.-_ 24,25,26,27,38

Paranannites Hyatt and Smith...--------------_--------------- 24, 26, 27, 39,98

aspenensis Hyatt and Smith- -- 2, 3,8,10,16,27,41,44,46, 53, 58, 65, 66, 98, 99,

pis. 8, 73 

columbianus Smith, n. sp.---------_-__ T ._-_-__-_ 2,8,99, pi.32

compressus Smith, n. sp_-------------------------------------- 2,8,99, pi. 31

pertenuis Smith, n. sp__--------_ 2,8,99, pi. 31

Paranorites ambiensis Waagen..__ ..____ ____ _ _ __ - 102, pis. 19, 52

Parapopanoceras Haug____...__-____..____.__...-__.__ 26,27,39 

Parapronorites Gemmellaro--___..._._..._-------------_ 21. 24,25,27,36

Paratirolites Stoyanow. 25, 28, 30, 31, 33

kittli Stoyanow--------.--__. _ -_ -. _ - _--------- 16

Paratropites sellai. . .__. - .-- -------------.-- 22, 27, 37,105

Pentacrinus smithi Clark and Twitchell__ __------------------------- 11,83

Perrinites.------------------___._. __------------------__- 26,36,38

Phelan ranch, Elko County, Nov., Meekoceras zone of, general features and

fauna of.__.___.--.__.________.___.._'. . 9-10 

Pheinacoceras___---------__---------------_........................... 25

Phlippites Diener .-.--.--.----_-.--------------------------------- 23,31,32

Phylloceras- -- ----.------- 30,33

ramosum.-__ __.---____---------_.-__.--.__---------- 33

Phylogeny of Triassic ammonites, limitations of field considered in study of- 21-22 

methods of study of..._____ _--------------_------------------ 20

principles of interpretation of ------------------------------------------ 21

recapitulation of, with examples.-----------------.---------------------- 22-23

summary of.------------------------------------------------------------ 25-26

Pinacoeeras-.--.._ _... .... - - - 33

Pinacoceratidae, phylogenetic classification of.-..--.....-_..._.__-_--.----- 33

Polycyclus-----------------.-...---.------------------------------------ 23,27

Popanoceras____ __.---_-.-------------.........----------------- 24

Prenkites Arthaber...... 29,110

depressus Smith, n. sp...--------------------------- 2,8,66, 110-111, pi. 31

malsorensis Arthaber-- - - - - 110

Prionites Waagen.... _-.._. _ . - - --- 25, 28,31

laevis Welter..-... _____. - 17

undatus Waagen - - . 17

Prionolobus falcatum, Waagen.- -- 45

gracilitatis Frech-..________._. ._ ___ ____ __ __ - __-_ 57

jacksoui. .. ---------- _ __.- 49

mushbachanus Frech..............-......................---------_-..... 61

Proavites Arthaber .... ---------------------. 27,28,30,31,40

Procarnites Arthaber..----..-----------------------.------------------ 25,28,34,35

kokeni Arthaber___....______..__..._____-___-._------__ 19, 20

skanderbegis Arthaber---- - - - - - _ 19, 20

Proceratites . ______ _ ._._._ _ _ 42,46

Prodromites Smith and Weller......____....__------___-___ 24,25,26,34

gorbyi Miller .._ . ._ _ 24, pi. 43

Prolecanites _- ...-..- -.-.---.-- ---. 22, 23, 25, 26, 27, 30, 33, 34, pi. 59 

applanatus Frech___...____ .. ------__-------------- 23, pi. 44

Prolecanitoidea . - .... -- -- - 29-34,39-85

Pronorites Mojsisovics. - 21, 22, 23, 24, 25, 26, 27, 34, 35, 36, pi. 45

Page 

Pronorites mixolobus .. ...--.......-.-----------.-------------------... pi. 71

praepermicus Karpinsky................................................ pi. 71

timorensis Haniel---------- - - - --- --- -- -- --------- - 24, pi. 45

Pronoritidae____________.................__._------------ 35-36,94-95

Pronoritoidea-..-_______-------------____-------_. . __ 35-36,94-97

Propinacoceras Gemmellaro--- -------------------------------------------- 27, 36

beyrichi Gemmellaro__------_....................................... pi. 71

Proptychites Waagen... . . 29,31,39,101-103

ammonoides Waagen - .------------------------------------__ 63

latifimbriatus Waagen__................................_----.--.... 20

scheibleri Diener--___............................_......_..__.. 15

walcotti Hyatt and Smith ....... . ..... . . . 3,9,108, pis. 19,52

Prosphingites Mojsisovics...-.-_ __._.__.__ 26, 27, 36, 38, 97-98 

aequitorialis Smith..___.............................................. 16

ali Arthaber_.____.....-....--------..........-.--._-----_..__ 20

austini Hyatt and Smith ._ __ ....__ 3, 9,16, 98, pi. 7

czekanowskii Mojsisovics----------------------_.-------............... 97

nala Diener___---------------------_------.-.----.-..-------------. 15

Proteites Diener__-------_...........__............................... 102

ProteusitesHauer_____-_____.___-__._..._________ 39,103 

kellneri Hauer__--------------___---------_-------.----------... 102

rotundus Smith, n. sp - _ _- - - 3, 9,1O3-103, pi. 53. 

striatus Hauer__..................___-------------_------__.... 103

ProtrachyceraS---.-_ _------.-------.-..... 23

Protropites Arthaber__-____.__.__-_ ._-__...._._ 26, 29, 36, 37

hilmi Arthaber.__.__._______.________.__....__ 20

Pseudharpoceras Waagen__............__..._..-_._-.-.-.-_ 20, 28, 81

idahoense Smith, n. sp.__-__._______._ passim 3-108, 81-83, pi. 49 

praematurum Arthaber._.......__------_........................ 7,82

spiniger Waagen.........._............................................ 81,82

Pseudomonotis idahoensis White. - -- -- -- -- ----- - 11

pealei White.----------------------------------------------------------- 11

Pseudosageceras Diener-. -- -- - 21, 23, 24, 25, 28, 34, 87

drinense Arthaber___.................___-_ - ------__-- 7, 20

intermontanum Hyatt and Smith.............._............__------ 87,88

multilobatum Noetling... .-.. . passim 2-111, 87-89, pis. 4, 5, 25, 60, 63 

sp. indet. Diener--__ __.-.-__ __--___-------------------- 16, 87

Pseudosageceras multilobatum subzone, characteristic species of. - ------ 16

general character of fauna of_ - _ _._-._ 15-16

geographic distribution of.__..--------.--.--------.-----.---------...- . 13

Pseudosibirites Arthaber- ---- ----_------_...... 69

Ptychites .... . .. . . . - .-.. 39

Ptychitidae..__-_______.--... ...______.__-____....._.. 39,98

Ptychitinae.---------------------------------------------------------------- 99

Pugnoides triassicus Girty___-----.---...----------------_-----.---------- 11,83

R 

Radicles, general features of.-.-- ----------------------------------------- 23-25

Reiflingites Arthaber__--------------------------------------------------- 32

Rhacophyllites. _-------------------------------------.----------.------. 33

Sageceras Mojsisovics.-------- ----__..........__...-...-.-.-. 23,24,25, 28,34

albanicum Arthaber_..-........_.--------.........._---------------- 20

gabbi --- -.- 27, 89, pis. 45,60

Sagenites__________....__.-. .......... .. ....__....... 22, 38, pi. 58

herbichi Mojsisovics------------------------------------------------- 27, pi. 58

Semiornites Arthaber_ -. 32

SchistocerasHyatt , _ .. . . -..-..-. 24,26,27

Shumardites-.--___-------__ __.....__.-.___-_ 26,27,36,38

Sibirites Mojsisovics .- -- . 28,31,38,69

angulosus Waagen_------------------------_------------_------- 70

eichwaldi Keyserling..--------......................................... 70

hircinus Waagen.._____------__.._--------_____..__.___ 72

ibex Waagen.-.- ___.__ _. __.__.___.... .__._ .. 70

kingianus Waagen ..........................._........-............... 69,72

noetlingi Hyatt and Smith----.------.------------------.-.------------. 74

prahlada Diener___----.-.-........--.---...-...................-.... 19

pretiosus Mojsisovics------------------- -------------------------------- 20, 70

tenuistriatus Waagen__-------------------__........................ 74

"Sibirites" spiniger, zone of -- - __------.-..-------.-----..- 17

Sibyllites._______________.--.-..____________-__ __ 38 

Sicanites Gemmellaro------------------------------------------------------- 25,36

mojsvari Gemmellaro--_ -. - . --- -------- pi. 71

Sirenites..---- --------------.------------------ ----- 33

Smith, J. P., Hyatt, Alpheus, and, cited. 

Smithoceras Diener.------_ _.

Stacheites Kittl-..__---------------..

Stacheoceras.--.------------------------.

.- . - 32 

. .. . 29

 28

 24

Stephanites.___._____..._---------_____...._.._________ 26,29

superbus Waagen.-------------------__.. .._._._.__ ------- .. 17

SturiaMojsisovics ..-..---.-------------.-... ..._ 25,28,35,93

compressa Hyatt and Smith-_......__._____ 3,9,59,65,90,93-94, pi. 3

woodini Smith, n. sp_._--.-.--..----.---..--.-----..------..- 3,9,94, pi. 51

Styrites Mojsisovics.-------.------------------------------------------_ 26,29

Sundaites Haniel-. . _. -... ___ . - . 25,36
INDEX 199

T Page

"Toxitos" ............. . . - -. . 23

Tlmlassocoras.__...... ._ ..... . .- 23,25,27,34,35

gommollarol Knrpinsky.............................. ..-- .... 92, pi. 42

inicrocllsciis._____.........--.-.-._..-. ..-...-_. ..-. 35

phlllipsi Goimnollaro__........_...______.._____-__ 92, pi. 42

Thnlassoccratldao..__.___._-____.__.-.'._______-__ 35,90-91 

Thormalitcs Smith............................................ 24,26,27,29,38,111

thermaruiii Sinith........................-.----. 2,8,27,110,111, pi. 21

Tibotitcs - - 35

Timanitos Mojsisovics.. ........ ............ 22,24,25,26,27,34, pi. 60

ucutus Koyscrllng..................._......-....----.---.-.- .. 24, pi. 44

TiinorltcsHaiilol..-.-............-..-----------.------------------------- 26,36,38

Tirolltos Mojsisovics............--.---------------------------------- 28,32,33,83

cnsslanus Quonstodt.___.... . -. 7,17,83 

ImrU Sinith, n. sp................................... 3, 7,11,18,81, 83, 84, pi. 57

Imiiori Mojsisovics-..-----.-.-........_. . 7,83

idriiuius Miojsisovics_..................__----------_________ 18

lllyrlcns Mojsisovics .. ... ........................ 3,7,11,18,20, 84, pi. 49

knighti Smith, n.sp.. .................... - 3, 7,11,81,83, 84, pi. 57

moriciiaiius__-....-._........-.------.--.-------..-..----_'.____ 19

pcnloi Smith.................................... 3,7,11,18,81,83, 84, pi.57

(luonstoclti M'ojsisovics.... - . _..-.--------------.-- . 18

rcctangularis Mojsisovics.............----.-.-- ..._..----_ ._..-. 20

sominiidiis Mojsisovics....-..---------....-...__-------_-------- 18,20,59

srniriagini Aucrbach..____....______ __._ ..__ 7

spinosl__._..........__ __...___ ___ __... 18,83

Tirolitcs zone, characteristic species and general character of fauna of...--_ 18

geographic distribution of_ ...--.___ ... .. 13

Toruocorns___-________________________________ 39

Tracliycoras_______________.__.___________________ 33

opolonso Miojsisovics___...-...-.--_...-------------_------------ 104

Trachyccratoa_____-...........---------.-----------------------.---. 33

Tropicoltites....________ ............................................'.. 38,81

praoinatiiriis Arthabor__..__..----.----.---------------.----------.. 81

Tropignstrltos_________....-_____________-.._---- 21, 22, 24, 27, 37

Imlli...........-.-.....---.........-.-.-.-....-..............-------.- 22, pi. 58

laliontanus Smith....___..._____.________.....-.-__ 22, pi. 58

trojanus_____.....-.-.....-------......_----------------------- 22, pi. 58

Tropitcs ....._.............................................. 21, 22, 24, 27, 36, 37

occidentals Smith...___...______________.--.. .__ 22, pi. 58 

subbullatus....._.....-..-................--------------..-------- 22,37,105

torquillus Mojsisovics...______.-.._________________ 22, pi. 58 

wollori Smith......__._.......-......-.---------------.---------- 22, pi. 58

Tropitidao, phylogonctic classification of.....___.______________ 37-38

Tropitoidca.................-.......-..-.-...........-.--..-.-...-.-. 36-38,103-111

U

Uddonites Base............................................ 21,22, 23, 24, 25, 27,35, 36

sclmchorti Bo'so.-____.________.________________ 24, pi. 45

UssuriaDionor... . .. 21,23,25,28,29,34,35,91, pi. 60 

cornprossa Hyatt and Smith......_____..-.._______ _____ 93

iwanowi Dloncr...._____....._...__............ 7,16, 91,92,93, 94, pi. 66

Page 

Ussuria occidentalis Smith, n. sp_---------------------------- 2,8,91-92, pi. 27

schamarae Diener..._.________________.________ . 92,93,94 

waageni Hyatt and Smith......... passim 2-111,93-93, pis. 21,42,60,65,66,67

Utah, Anasibirites fauna of_----------- ____-------------- .. 3,10

V 

Vishnuites Diener-___________..._____-..__............___ 28,80

Waagenoceras______.-.___--------_..._______._.__ 26,36,38

Wasatchites Mathews___-.-.--.--.---..----.......--.-.--.--.----..-.--- 66

magnus Mathews..__ . _--------- 67

meeki Mathews__-------------------_--.----..---.--.-_----------- 67

perrini Mathews___-_.----.----.------.-.........-----..----------- 67

quadratus Mathews._____----- ----___-________ 69

Wyomingites-.__.....---.-.-.--.--......-....-.......----------.-.....-..- 42

aplanatus Hyatt....-...-.-.........-.-.----........-.-.---------..---.-. 51

Xenaspis AVaagen.... .....-....-....................---... . 25,30,33, 46-48

(?) aplanata Waagen...---_--------- --.----.-.---------__ 51

carbonaria Waagen ------------ --------------------------- --- 43,47

marcoui Hyatt and Smith- .__-.-.- ___.__-. . 47, pi. 7 

nevadanus Smith, n. sp__.._....---..._...._....---__ 47-48, pi. 56

Xenodiscidae-__--..........-....------- -.-.-.-----------.-__ 29-31,39-40

Xenodiscus Waagen.- ------ 21, 22, 23,25, 28,30, 31,32,33, 34, 36, 37,43-43, 46

aplanatus Mojsisovics-__ __ ___ - __ -. 51 

bittneri Hyatt and Smith__.-....--. -........-----------_------- pi. 59

carbonarius Waagen .. ---------------..-..-- ------------ 43

cordilleranus Smith, n. sp_____ -__...__---------- 1,2,8,43, pi. 24

coronatus White___----.-----------------.-...-.--------.------------- 16

douglasi Mathews -- -.--. -------------------- 45

euomphalus Keyserling _ __--. - -------- 7

gilberti Smith, n. sp -______-__..--.....__--.._ 1,8,43-44, pi. 24

hannai Matbews ---------------------------------- .. .. 44

himalayanus Oriesbach__.----------------------.----------.---------- 15,45

intermontanus Smith, n. sp. .___-________ 1,8,43,44, 65,109, pi. 24 

jacksoni Hyatt and Smith.__ ____ 20 

marcoui Hyatt and Smith. .............. ...... .. 2,9,43,47, pi. 7

nevadanus Smith, n.sp.______.. ___ 2,9,47-48, pi. 56 

nivalis Diener.. .... 2, 3, 6, 9,10,15,16, 27,43, 44, 64, pis. 56,79

plicatus Waagen..-. 42,43,47,48

radians Waagen__ ----- .......................................... 15

rotula Waagen 3,6,10,15,43,45, pi. 79

schmidti Mojsisovics 7,20,44,66, pi. 29

strong! Hyatt and Smith__ _____ 9

sulioticus Arthaber. ,, 20

tarpeyi Smith, n. sp.______......__-___.. -______ 1,8,45, pi. 25

toulai Smith... 1,3,8,9,43,45-46, pis. 25,55

waageni Hyatt and Smith....... . .i 1,2,8,9,43,46, pis. 23, 39, 49

whiteanus.(Waagen) ...................................... 1,8,43,46, pi. 32

o