North American Species of Tempskya and 

Their Stratigraphic Significance 

GEOLOGICAL SURVEY PROFESSIONAL PAPER 874 

North American Species of Tempskya and 

Their Stratigraphic Significance 

By SIDNEY R. ASH and CHARLES B. READ 

With a section on STRATIGRAPHY AND 

AGE OF THE TEMPSKY A-BEARING ROCKS 

OF SOUTHERN HIDALGO COUNTY, 

NEW MEXICO 

By ROBERT A. ZELLER, JR. 

GEOLOGICAL SURVEY PROFESSIONAL PAPER 874 

A description of two new species of the Early Cretaceous 

tree fern Tempskya and a discussion of the characters and 

distribution of the other North American species 

UNITED STATES GOVERNMENT PRINTING OFFICE, WASHINGTON 1976 
UNITED STATES DEPARTMENT OF THE INTERIOR 

GEOLOGICAL SURVEY 

V. E. McKelvey, Director 

Library of Congress Cataloging in Publication Data 

Ash, Sidney R 1928-

North American species of Tempskya and their stratigraphic significance. 

(Geological Survey professional paper ; 87 4) 

Bibliography: p. 

Includes index. 

Supt. of Docs. no.: I 19.16:874 

1. Tempskya. 2. Paleobotany-Cretaceous. 3. Paleobotany-New Mexico--Hidalgo Co. 4. PaleobotanyNorth America. 5. Geology, Stratigraphic-Cretaceous. I. Read, Charles Brian, 1907- joint author. 

II. Title. III. Series: United States. Geological Survey. Professional paper ; 874. 

QE965.A83 561'.73 75-619201 

For sale by the Superintendent of Documents, U.S. Government Printing Office 

Washington D.C. 20402 

Stock Number 024-001-0732-1 
CONTENTS 

Page 

Albstract ---------------------------------------- 1 

1 

2 

2 

6 

6 

6 

6 

6 

9 

9 

Stratigraphy and age of the Tempskya-bearing rocks 

of southern Hidalgo County, New Mexico, by Introduction ____________________________________ _ 

AlcR:nowledgments ____________________________ - ___ _ Robert Al. Zeller, Jr ----------------------------- History of investigations of Tempskya -------------- Introduction ________________________ --------- Occurrences of Tempskya in the United States ______ _ Cretaceous stratigraphy _________________ - ___ -- In-place specimens ---------------------------

Rocky Mountain geosyncline ---------------

Blackleaf Formation -----------------·-

Late Allbian biota in the Mojado Formation 

Biota in the type Mojado Formation in 

Colorado Group (undifferentiated) ____ _ 

Wayan Formation --------------------

Aspen Shale -------------------------

Thermopolis Shale --------------------

Willow Tank Formation -------------- Cedar Mountain Formation ___________ _ 

Burro Canyon Formation ____________ _ 

Dakota Sandstone --------------------

Mojado Pass ---------------------------

Biota in the Mojado Formation of the 

Alnimas Mountains ----------------------

Conclusions rzgarding the age of the biota __ 

Systematic descriptions ---------------------------

Tempskya reesidei Ash and Read, n. sp ________ _ 

Mexican geosyncline ----------------------

Mojado Formation --------------------

Altlantic Coastal Plain --------------------

Patapsco Formation -------------------

tO 

10 

11 

12 

12 

13 

13 

13 

13 

14 

Tempskya zelleri Ash and Read, n. sp -----------

Comparisons of the species of Tempskya -------------

Synopsis -----------------------------------------

Selected references _________ --- ___ ----------------

Reworked specimens __________________________ _ Index -------------------------------------------

PLATES 1-4. 

5-7. 

8. 

9. 

10. 

11. 

12. 

13. 

FIGURE 1. 

2. 

3. 

4. 

5. 

6. 

7-11. 

ILLUSTRATIONS 

Tempskya reesidei Ash and Read, n. sp. 

Tempskya zelleri Ash and Read, n. sp. 

Tempskya knowltoni Seward. 

Tempskya minor Read and Brown. 

Tempskya grandis Read and Brown. 

Tempskya wyomingensis Arnold. 

Tempskya wesselli Arnold. 

Tempskya superba Arnold. 

[Plates follow index I 

Reconstruction of Tempskya rossica by Kidston and Gwynne-Vaughn --------------------------------

Reconstruction of Tempskya by Andrews and Kern -------------------------------------------------

Index map of the United States showing general location of occurrences of Tempskya spp ------------

Correlation chart of parts of the Cretaceous system in the United States showing rock sequences where 

Tempskya spp. have been reported ----------------------------------------------------------- Index and topographic map of part of southwestern New Mexico showing known exposures of the Mojado 

Formation, Tempskya localities, and the type sections of the several Cretaceous formations mentioned 

in this report ----------------- _____________________________________________________________ _ 

Stratigraphic sections of the Mojado Formation ---------------------------------------------------

Drawings: 

7. Cross section of the false trunk of Tempskya reesidei n. sp ---------------------------------

8. Reconstruction of the basal part of the false trunk of Tempskya reesidei n. sp ----------------

9. Cross sections of the false trunk of Ten'"pskya reesidei n. sp __ ----------------------------

10. Cross section of the false trunk of Tempskya zelleri n. sp ----------------------------------

11. Diagrammatic sketches of the well-known species of Tempskya ----------------------------

III 

Page 

16 

16 

17 

18 

20 

21 

22 

22 

25 

28 

31 

33 

36 

41 

Page 

4 

5 

7 

8 

16 

19 

27 

28 

29 

30 

34 

NORTH AMERICAN SPECIES O·F TEMPSKYA AND 

THEIR STRATIGRAPHIC SIGNIFICANCE 

By SIDNEY R. AsH and CHARLES B. READ 

ABSTRACT 

Two new species of the fossil tree fern Tempskya-T. reesidei 

and T. zelleri-are described in this report. Both are from the 

Lower Cretaceous Mojado Formation of Hidalgo County, N. 

Mex., and are associated with marine invertebrates that date 

them quite adequately. T. reesidei is somewhat smaller than, 

but reminiscent of, T. grandis, whereas T. zelleri appears to 

be related to the group that is characterized by T. knowltoni. 

The report also contains a history of the investigations of 

Tempskya and a resume of the 43 reported occurrences of 

Tempskya in the United States. In-place occurrence of the 

genus Tempskya in the United States now total 34; all but one 

are from west of the Mississippi River, and most of them are 

in strata in the Rocky Mountain area. In addition, rocks of 

Late Cretaceous or Cenozoic age, particularly, contain much 

reworked Tempskya material, once again in the Western 

United States. 

In-place occurrences of the genus Tempskya seem to be mainly in rocks of latest Early Cretaceous (Albian) age, as 

indicated by the associated invertebrate fossils. The age of a 

few of these localities, however, is still questioned by some 

observers. 

INTRODUCTION 

In 1955, Robert A. Zeller, Jr., of the State Bureau 

of Mine~ and Mineral Resources Division of the New 

Mexico Institute of Mining and Technology, showed 

the junior author of the present report a peculiar 

specimen of obviously organic origin in an effort to 

obtain an approximate generic identification. The 

specimen was a poorly preserved cast in fine-grained 

sandstone. Read expressed the opinion that the 

specimen might be a fragment of the enigmatic fern 

genus Tempskya rather than a sponge which it 

superficially resembled. Later in 1955, the junior 

author accompanied Carle H. Dane, of the U.S. 

Geological Survey, and Zeller to the locality in the 

southern part of the Big Hatchet Mountain area, 

Hidalgo County, N. Mex., where the fossil had been 

obtained. On that trip, many well-preserved speciments of Tempskya were collected. At first (Zeller 

and Read, 1956), these specimens were thought to 

be examples of Tempskya ';ninor Read and Brown. 

Additional study, however, now indicates that the 

species actually differs from all others, and it is 

described as Tempskya zelleri n. sp. in this report. 

During the 1955 field trip, Zeller pointed out that 

the specimens of Tempskya were associated with 

many marine invertebrates. A few collections of the 

invertebrates were made and sent to the late John B. 

Reeside, Jr., for study. Later in 1955, and from then 

until his death in July 1958, there was active correspondence between the authors of this report and 

Reeside concerning the nature of the occurrence and 

the .age of the containing strata. In the spring of 

1956, Reeside visited the localities in Hidalgo County 

and m·ade additional collections of the invertebrates. 

As indicated elsewhere in this report, he concluded, 

on the basis of the marine fossils, that the containing rocks are Early Cretaceous (Albian) in age. 

Continued correspondence between Reeside .and 

Read led to speculation that all the American occurrences of the genus Tempskya may be in Albian 

strata. Unfortunately, before Dr. Reeside's death, it 

was impossible for the junior author of this report 

to go into the details of the many occurrences. However, early in 1959, a detailed study of the new 

species from the Big Hatchet Mountains began, 

together with the assembling of data on American 

occurrences in general. 

Later in 1959, Robert A. Zeller obtained additional 

specimens of Tetnpskya in similar Cretaceous marine 

strata on the eastern flanks of the Animas Mountains, Hidalgo County, N. Mex. These specimens 

were determined to belong to a second new species, 

here to be named and described as Tempskya 

reesidei. In 1960, the authors of this report visited 

the locality with Zeller and collected a considerable 

quantity of material, including additional pieces of 

the false trunk of the holotype and of the paratype 

as shown in figure 8. 

It was then decided to reevaluate the various 

species of Tempskya that are known in the United 

1 
2 NORTH AMERICAN SPECIES OF TEMPSKY A 

States, both as regards their morphologic characteristics and also the stratigraphic occurrences. The 

principal product of the study is this report, although a preliminary paper assessing the stratigraphic value of Tempskya in the western United 

States has been published (Read and Ash, 1961b). 

Early during this investigation it was recognized 

that the association of marine invertebrates with 

Tempskya in southwestern New Mexico was especially significant. As a result, during the mid-1960's, 

Zeller prepared a section for this report in which he 

discussed the Lower Cretaceous stratigraphy of the 

area and described the occurrence of invertebrates 

with the fern in some detail. Since then, it has 

become necessary to make a few changes in the section in order to bring it up to date. Unfortunately, 

Zeller's unexpected death early in 1970 prevented 

him from seeing these changes. They, however, are 

so small that they do not modify the section in any 

essentials, and it is still very close to the version 

originally submitted by Zeller. 

ACKNOWLEDGMENTS 

The writers are indebted to Professor Chester A. 

Arnold, University of Michigan, for the loan of type 

slides and the gift of type material of Tempskya 

wesselii, T. wyomingensis, and T. superba, which 

have been used in this report. We are also indebted 

to Sergius H. Mamay and Arthur D. Watt, U.S. 

Geological Survey, for the loan of thin sections and 

type material of T. grandis, T. knowltoni, and T. 

minor, and also for locality data regarding occurrences of Tempskya. E. Guerry Newton, U.S. Geological Survey, has checked the bibliography used 

in this report. 

John D. Strobell, U.S. Geological Survey, made a 

special trip to the Carrizo· Mountains, Ariz. and 

N. Mex., to help the junior author collect from a 

locality earlier discovered by Strobell. Thanks are 

here expressed for the interest and encouragement 

given by the late Carle H. Dane, U.S. Geological 

Survey, in connection with the study. 

The late Esther R. Applin, U.S. Geological Survey, 

supplied helpful information on the vertical range 

of Cribratina texana, one of the critically diagnostic 

Foraminifera used in stratigraphic correlation of 

the Lower Cretaceous rocks in southwestern New 

Mexico. Mr. Takio Suski, University of California, 

Los Angeles, identified some of the earlier invertebrate collections that were made by Zeller. The staff 

of paleontologists of the U.S. Geological Survey and 

the U.S. National Museum (Natural History) have 

made identifications of most of the collections of 

invertebrate fossils, and their contributions are 

acknowledged with thanks. They include Norman F. 

Sohl, who studied the gastropods; Ruth Todd, who 

examined the Foraminifera; the late John B. Reeside, Jr., who reviewed the entire fauna; and W. A. 

Cobban, who worked on the marine fauna from the 

Animas Mountains. 

Dr. Eugene Callaghan, former director of New 

Mexico Bureau of Mines and Mineral Resources, 

supported and personally encouraged the earlier 

efforts of Zeller in connection with the stratigraphic 

study of the Cretaceous rocks that led to the discovery of Tempskya in southwestern New Mexico. Mr. 

Allen M. Alper of the Corning Glass Company 

worked with Zeller in the mapping of the Mojado 

Formation in the Animas Mountains, a project that 

led to the discovery of one of the new species here 

described. 

The assistance of Mr. W. R. West, Carolina Biological Supply Company, who supplied us with information on the new occurrence of Tempskya in 

North Carolina, is appreciated. 

Finally, the writers wish to acknowledge particularly the aid and encouragement of W. W. Rubey 

and the late John B. Reeside, Jr. Rubey, who for 

many years has conducted stratigraphic and structural studies in western Wyoming and adjacent parts 

of Idaho, is responsible for many of the discoveries 

of Tempskya localities and has provided much 

thoughtful and helpful information regarding the 

stratigraphic occurrences. Reeside encouraged 

Brown and Read during their earlier investigations 

of Te1npskya and was both extremely interested in 

and actively concerned with the occurrences of 

Te1npskya in southwestern New Mexico. 

HISTORY OF INVESTIGATIONS OF TEMP SKY A 

In 1937, the junior author and one of his associates published a historical statement regarding 

the genus Tempskya. The report (Read and Brown, 

1937) has been out of print for some time. In consequence, a summary is needed of the historical account earlier published. 

The first written record of Tempskya is an account of Endogenites erosa (Stokes and Webb, 1824) 

in a report on the plant material collected by Mantell 

in Tilgate forest. The plant material was believed 

to have affinities with palms, hence the name. 

Cotta (1832) described similar material under the 

name Porosus marginatus and suggested that it 

might be part of a large fern stem. Mantell (1833) 

agreed with this opinion after reexamining m~aterial 

he himself had collected some 10 years before. 
HISTORY OF INVESTIGATIONS 3 

Fitten (1836) described similar material collected 

near Hastings. He returned apparently to the opinion of Stokes and Webb (1824) and referred the 

specimens to Endogenites erosa. 

Unger (1845) reexamined the material under 

question, as well as new collections, and expressed 

his opinion that Endogenites erosa was simply a 

mode of preservation of Protopteris. Protopteris 

was the generic name used in the early days of paleobotany for certain fern ste111s that were either petrified or preserved as casts or molds. 

In 1845, Corda published his observations on a 

large series of petrifications of various types and 

established the genus Tempskya in honor of a contemporary naturalist, Tempsky. The type material 

was four specimens from localities in Bohemia and 

adjacent regions. The generic description (Corda, 

1845, p. 81) is as follows : 

Truncus * * * Rachis rotundata, plicata vel alata; cortice 

crassiuscula, fasciculis vasorum ternatis, majori clauso vel 

lunulato et supra incurvo, minoribus oppositis lunulatis. 

Radices minutae numerosissimae; fasciculo vasorum centrali 

unico. 

Corda's interpretation was that Tempskya was a 

member of the Phthoropterides. The material was 

believed to be silicified masses of branched petioles, 

sheathed by a thick mat of roots. The species T. 

pulchra, T. macrocaula, T. microrrhiza, and T. 

schimperi were described. The preservation of the 

material that Corda studied appears to be rather 

poor. In consequence, although the account is historically quite important, few data of morphological 

value resulted from the investigation. 

In 1871, Schenk suggested that Tempskya is a 

complete stem of marattiaceous affinities, the vascular bundles being sheathed in a ground mass of 

parenchyma and sclerenchyma. 

Feistmantel in 1872 suggested that Tempskya is 

not a valid genus but rather a type of preservation 

of certain kinds of fern stems. This opinion impressed a number of investigators, and several 

papers were published in support of the opinion. 

Velenovsky (1888) supported the theory and produced additional corroborative evidence. 

Seward, in his catalog of the Wealden flora published in 1894, included a very interesting and valuable account of the literature on Tempskya. Feistmantei's ideas were seriously questioned, although 

not completely discredited. Seward's conclusions 

( 1894, p. 158) are as follows: 

In Tempskya schimperi we have masses of branched diarch 

fern roots associated with petiole axes, which occasionally 

afford evidence of branching; probably some forms of Tempskya 

and Protopteris are very closely related, if not identical plants; 

but, so far as English specimens are concerned, there is an 

absence of any direct proof of such organic connection between 

the two fossils, as Feistmantel and Velenovsky have previously suggested. 

The true nature of Tempskya was first tentatively 

hinted in 1897 by Stenzel, who offered three possible 

morphological explanations: 

1. Lateral organs of a tree fern growing downward 

and encased in downward-growing roots. (This 

hypothesis is similar to that suggested by 

Corda, although not identical with it.) 

2. Independent stems climbing upward between 

roots. 

3. Upward-growing and branching fern stems encased in their own downward-growing roots. 

Stenzel appears to have preferred the third explanation, although there is no final commitment. 

This explanation is the one accepted by all later 

investigators. 

Detailed morphological studies of well-preserved 

Tempskya material were carried out for the first 

time in 1911 by Kidston and Gwynne-Vaughan. 

These investigators described T. rossica from the 

Karanganda River basin in Russia. Although the 

material is very well preserved, its geologic age is 

uncertain; the material came from a Tertiary conglomerate but, in the opinion of all investigators, 

has been reworked from older strata. These investigators concluded that the siliceous masses that had 

caused so much speculation in the past were false 

trunks, or dichotomously branching systems of stems 

sheathed in a mass of adventitious roots. Kidston 

and Gwynne-Vaughan speculated on the growth 

habit of T. rossica and suggested that it may have 

stood erect and produced a crown of leaves or fronds. 

Although they were unable to establish close affinities, they suggested that Tempskya belongs in some 

family of the Leptosporangiatae. 

The first American material referred to Tempskya 

was described by Berry (1911b) from the Patapsco 

Formation of the Atlantic Coastal Plain. The material is poorly preserved, and although the validity 

of the generic identification is unquestioned, Berry's 

account of T. whitei does not contribute greatly to 

morphological knowledge. 

In 1915, Dr. Marie Stopes presented a summary of 

investigations of Tempskya in the catalog of Lower 

Greensand plants of Great Britain. In addition, she 

redescribed T. erosa which, as stated above, was the 

first S'pecies to be noted. Stopes included a reconstruction of T. rossica which was provided by Kidston and Gwynne-Vaughn. The drawing shows an 

erect false trunk with a terminal cluster of small 

fronds similar to those borne by modern tree ferns 

and cycads. (See fig. 1.) 
4 NORTH AMERICAN SPECIES OF TEMPSKY A 

FIGURE !.-Restoration of Tempskya rossica 

by Kidston and Gwynne-Vaughn. The figure 

is based mainly on the specimen of T. rossica 

they described in 1911 from the Karaganda 

River basin of Russia. It was first publi~hed 

by Stapes ( 1915, text-fig. 5, p. 15) and is 

reproduced here with the permission of the 

Trustees of the British Museum (Natural 

History). 

Professor A. C. Seward of Cambridge University 

described the first well-preserved specimen of 

Tempskya from the United States in 1924. The 

specimen was obtained by A. C. Silberling in 1908 

from the Cretaceous rocks in the valley of the 

Musselshell River in central Montana. Because of 

the nature of the preservation, the specimen was at 

first interpreted as a caudal spine of the dinosaur 

Stegosaur2l3. (See Seward 1924, p. 485.) F. H. 

Knowlton recognized the true nature of the material, 

but, being busy on other investigations, suggested 

that it would be appropriate for Seward to study the 

specimen. Tempskya knowltoni is a very well preserved specimen, and the study in general corroborates that of Kidston and Gwynne-Vaughn on T. 

rossica. There is one significant difference between 

the two species, however. In T. knowltoni, the entire 

false stem is dorsiventral by reason of the orientation of the individual true stems; this arrangement 

caused Seward (1924, p. 505) to describe T. knowltoni as "a root-encircled bundle of stems, obconical 

and tapering, lying obliquely in the soil, a few of 

the stem branches bearing crowded fronds near the 

ground level." Seward suggested that Tempskya 

may be a member of the Schizaeaceae. This conclusion was arrived at partly on the basis of stelar similarities and in part on the characteristics of spores 

and sporangia that were found not only in T. 

knowltoni, but also in some of the English material. 

During the period 1930-35, W. W. Rubey and several of his associates were quite active in carrying 

out a mapping program in eastern Idaho and adjacent parts of Wyoming. Many specimens of Tempskya were collected from the Wayan Formation of 

Idaho and the Aspen Shale of Wyoming. These units, 

which are in part correlative, are classified as Cretaceous in age. The abundant well-preserved material 

collected by this group was of sufficient interest to 

Read and Brown that they decided to collaborate in 

an account. The report was published in 1937 and 

was an attempt to discuss all the Tetnpskya material 

known at that time in the United States. Two new 

species, T. grand1~s and T. minor, were described, and 

additional observations were published on T. knowltoni and T. whitei. 

Two groups or subgenera of Te-rnpskya were recognized on the basis of radial symmetry of the false 

trunks in one group as opposed to the dorsiventral 

nature of the false trunks in the other group. After 

the characteristics of the various species of Tempskya had been reviewed and compared with those 

of modern ferns, it was concluded that a new family, the Tempskyaceae, should be provisionally established inasmuch as within the Leptosporangiatae 

reasonable comparisons may be made between the 

species of Tempskya and the Schizaeaceae, the Loxsomaceae, and the Gleicheniaceae. 

Read and Brown (1937) speculated on the probable growth habit of the species of Tempskya and 

suggested that in the case of the group represented 

by T. grandis, all the facts, including the radial symmetry of the false trunks, supported the idea that 

these ferns had a habit similar to that of low tree 

ferns. However, they noted that the plants represented by the dorsiventral false trunk types typified 

by T. knowltoni might have had a liana- or vinelike 

growth habit. An attempt was made to discuss the 

stratigraphic significance of the American temp-
HISTORY OF INVESTIGATIONS 5 

skyas. Read and Brown concluded that in the Western United States, the genus Tempskya ranges in age 

from Turonian to Senonian. However, in the Eastern 

United States, T. whitei occurs in Albian rocks and 

hence is older than the western occurrences. These 

conclusions were, of course, based to a large extent 

on the opinions then held by invertebrate paleontologists regarding the age of the containing rocks. 

Material was reported from Wyoming, Idaho, Montana, Oregon, Nevada, Utah, and Maryland. 

In 1939, Read published a summary of his views 

on the growth habit of Tempskya and on the possible 

course of development of the habit. He restated the 

opinion that on the basis of the morphology of the 

false trunks there are two groups of Tempskya, one 

of which is radially symmetrical and the other dorsiventral. The dorsiventral false trunk types were 

believed to have been lianalike and also to have been 

the more primitive group. He speculated that the 

radial forms were developed from these climbing 

types as a result of the assumption of a free upright 

habit. This change may have been quite accidental, 

or possibly the result of an increase in rigidity of the 

composite organ because of. increase in size of the 

true stems. 

Another American who has studied Tempskya is 

Chester A. Arnold. In 1945, he described two new 

species, T. wesselii from Montana and Oregon and 

T. wyomingensis from Wyoming. The concept of two 

groups or subgenera of Tempskya proposed by Read 

and Brown (1937) was accepted by Arnold, with 

certain reservations, and he placed his new species 

in the radially symmetrical group. 

Later, Arnold (1958) described a new species of 

Tempskya from Nebraska and named itT. superba. 

This species is similar to T. g1·andis internally, but 

the stems of T. superba are larger than those of T. 

grandis. This new species also was assigned to the 

radially symmetrical group. 

In 1947, Andrews and Kern published a very excellent discussion of large collections of Tempskya 

material made by Thomas, Manion, and Andrews. 

Their report contributes very little to the morphological details described by Kidston and GwynneVaughn, Seward, and Read and Brown, but the paper 

has a very stimulating discussion of false trunk 

morphology. These investigators suggested that in 

all probability all the false trunks referred to 

Tempskya were originally radially symmetrical and 

that accidents of preservation are responsible for 

the alleged dorsiventral types. Their reconstruction 

of a radially symmetrical Tempskya shows a treelike 

fern in which the upper two-thirds of the false 

trunk is characterized by irregular clusters of small 

fronds (see fig. 2). Andrews and Kern made comparisons between Tempskya and H emitelia smithii, 

H. crenulata, Todea barbara, and Dicksonia fibrosa. 

In addition, they discussed the late Paleozoic zygopFIGURE 2.-Reconstruction of Tempskya by 

Andrews and Kern (1947). The figure is based 

mainly on specimens of T. wesselii Arnold 

(1945) from the Wayan Formation of southeastern Idaho. Reprinted with the kind permission of H. N. Andrews. 
6 NORTH AMERICAN SPECIES OF TEMPSKYA 

terid tree fern Clepsydropsis australis and pointed 

out analogies with Tempskya. 

In 1961, the authors of the present report reappraised (Read and Ash, 1961a, b) the stratigraphic distribution of Tempskya in the western 

part of the United States in the light of modern 

data. We showed that specimens of the genus often 

occur in or adjacent to marine units containing invertebrates of latest Early Cretaceous (Albian) age. 

We concluded, therefore, that the age of Tempskya 

is more restricted than formerly thought (Read 

and Brown, 1937) and that the genus is probably 

of latest Early Cretaceous (Albian) age in the Western United States. 

In 1968, a new Te,mpskya was described from 

southern England by Chandler. The single small 

specimen on which her study is based resembles T. 

grandis, but because of the limited amount of material available, it was not referred to a species. The 

age of the specimen is questionable, as it was found 

on the surface of the beach at the famous upper 

Eocene London Clay plant locality near Sheppey in 

Kent. The new Tempskya is silicified, whereas plant 

remains in the London Clay are usually pyritized or 

preserved in some other manner. Thus, it seems 

unlikely that the new Te,mpskya was originally deposited in the London Clay. Chandler suggested 

( 1968, p. 179) that the most likely source of the 

specimen is the lower Eocene Woolwich Beds, which 

are exposed at nearby Herne Bay and which contain 

silicified dicotyledonous wood. Another likely source 

for the specimen is the Lower Cretaceous Lower 

Greensand, which is exposed in nearby areas and 

which yielded T. erosa, the first species of the genus 

to be recognized. 

Several nicely preserved specimens of Tempskya 

have been reported from gravel deposits in Harnett 

County, N.C., by West (1968, 1970) of the Carolina 

Biological Supply Company. The fossils have not yet 

been described, but pictures supplied by Mr. West 

show that they do not represent any of the species 

considered in this report. 

OCCURRENCES OF TEMPSKY A IN THE 

UNITED STATES 

Specimens of Tempskya have been reported from 

about 43 localities in the United States (fig. 3). 

Most of the localities are in the Rocky Mountain 

geosyncline region of the western interior of the 

United States. Two are in the Mexican geosyncline 

area in the southwestern United States, and two are 

in the Eastern United States. Thirty-four of these 

localities contain specimens that are in place. These 

in-place specimens in the Rocky Mountain geosyncline area are considered first, by formations from 

north to south. Those in the Mexican geosyncline 

region and the one in the Atlantic Coastal Plain 

in the Eastern United States are then briefly discussed. Specimens that clearly have been reworked 

into Tertiary or Quaterna,ry formations from older 

rocks are dealt with last. Locality numbers used in 

the text 1are keyed to the index m:ap (fig. 3), and 

in-plac'e 'specimens are keyed to the correlation chart 

(fig. 4). 

IN -PLACE SPECIMENS 

ROCKY MOUNTAIN GEOSYNCLINE 

BLACKLEAF FORMATION 

The holotype of Tempskya wesselii was collected 

from the "bad lands" northwest of Great Falls, 

Mont., at locality 1 (fig. 4) by Louis Wessel (Arnold, 

1945, p. 26). The collector thought that the specimen 

came from the Kootenai Formation of Early Cretaceous age. It may have come, however, from the 

overlying Blackleaf Formation, which is also exposed in the area and which is known to contain 

Tempskya a few miles south of the "bad lands" at 

locality 2. Specimens of T. knowltoni have been collected from the Vaughn Member of the Blackleaf 

Formation (of the Colorado Group) west of Great 

Falls at locality 2, as reported by Cobban (1951, 

p. 2180). These specimens, which were identified by 

R. W. Brown, occur in the so-called red speck zone. 

An additional specimen of Tempskya sp. was collected by Fergus Mitchell in 1947 near locality 3. It 

probably was also derived from the "red speck zone" 

or adjacent strata. 

The Bootlegger Member of the Blackleaf, which 

overlies the Vaughn Member, contains the ammonite 

N eogastroplites, which is considered to be of late 

Albian Age (Reeside and Cobban, 1960, p. 17, 60; 

Cobban and others, 1959, p. 2792). Thus, the specimens of Tempskya in the Blackleaf are of late 

Early Cretaceous (Albian) age or slightly older. 

COLORADO GROUP (UNDIFFERENTIATED) 

The first well-preserved example of the genus 

Tempskya to be described from the United States 

was obtained by A. C. Silberling in 1908 in Montana 

at locality 4. The fossil was eventually sent to Professor A. C. Seward who published (1924) an account of the specimen, naming it T. knowltoni. At 

that time it was thought that the specimen probably 

came from the Kootenai Formation of Early Cretaceous age. Later, when Read and Brown (1937) 

redescribed T. knowltoni, they showed that the specimen undoubtedly came from what is now called the 

shale and sandstone member of the Colorado Shale. 
41° 

Baker0 X 

7(R) 

NEVADA 

' ' 

""' \.Las Vegas 

' 0 

~ \. 

CALIFORNIA 

OCCURRENCES 

I "l> 

3xl Gx 24(R) 

12X 

I 14 

191 ~16 20 X 171 

s-uxl 15~ 

---~X X 

I

I ~3(R)llx ~:822 Great --' 

1 Salt Salt Lake City I Lake 

I 

0 100 200 300 Kl LOM ETR ES 

I 

I 

NORTH DAKOTA 

\ 

~-----

~Q, 

Q,~ 

Q,~ 

0~ 

28(R) ----

0 Chadron 

NEBRASKA 

oDenver 

0 Santa Fe 

Albuquerque 

7 

FIGURE 3.-General location of occurrences (X) of Tempskya spp. in the United States. Numbers refer to localities mentioned 

in text and figure 4; (R) indicates that remains of this plant have been reworked from Cretaceous rocks into younger units. 
STANDARD CLASSIFICATION ROCKY MOUNTAIN GEOSYNCLINE (PART) 

(/) TEXAS GULF MONTANA IDAHO WYOMING 

LI.J EUROPEAN Upper part of Uinta and Lincoln Ci: COASTAL Northwestern part Southeastern part Central-eastern part Cokeville-Afton region Kaycee-Buffalo region LI.J STAGES Musselshell Valley Counties (/) PLAIN Localities 1-3 Localities 4-6 Localities 8-12 Locality 13 !Localities 14-18.21and22 Localities 19 and 20 Localities 26 and 27 

<;::: I I I ~~ 0: :§I,_ 

~;::: Q)- ·.;:; 1-o: .~ ~ <0 

~c( 0: Shales equivalent to 

u':; ;;; Ez CENO- Zc( Woodbine O:c. Floweree Shale Shale Frontier Formation *Porcelanite,shale, I 

se: ~; .e Frontier Formation o~ the Greenhorn 0:(/) Member (lower part) ~! I 

LI.J;:) MAN IAN ~(/) Formation 'i::co <I> sandstone, limestone, limestone and a..o ::::l!::!::! <O..c: ~ 

a..LI.J (!l minor coal beds. ~ 

~~. ~ Belle Fourche ::::lU ,..-... ~ 

~~0 - ?--._,..C-.....__.-'--.,__... Mostly nonmarine ~( Shale 7 ~ ..---- 'C 

Washita ger Member ~ Big ~~~~~rdstone *Wayan Formation *Aspen Shale *Aspen Shale Mowry Shale 1.1.. 0 

;::: Group ..... ~*Vaughn Member 8 *Shale and 0: (/) I Red shale Dark sha~ *Thermopolis ~i:dc;t~~~ ~·J Taft Hill (7 c( LI.J sandstone member Bear River and ':; sandston~anegated Ci: ~E Member ( Formation sandstone ~ Bear River Formation Bear River Formation and limestone· shale Shale :SK'S'~~1~eek ALBIAN LI.J (/) (/) Fredericks- §.! F19.Qd?~~,......_,__ "First Cat Creek Sand" l Tygee Ss. nonmarine :::;) Cloverly Formation h h r-- ?...__...."'.._/'~"---""' 

lTI~ 0 z burg Group ~~1'--'? 

~ t:ft ~ ~ --?__...--~___..---... 

LI.J c( ~ ~ 

u LI.J 

~ l~l ~ c( ::t: 1- u LI.J z ?~ ~ ~ 

0: c( u ::i: Trinity Beckwith Formation 0: 0 LI.J u Group ..-.. ,......_ ~?---.._v--.-..._v----.._ ,._......__~v--....7------.~~ ~~~ ?./"....--.....v--... (part) ~ GannettGroup (part) 

L APTIAN Kootenai Formation Kootenai Formation Gannett Group (part) Gannett Group (part) (PART) 

l.; Usage by U.S. Geological Survey now abandoned. 

STANDARD CLASSIFICATION ROCKY MOUNTAIN GEOSYNCLINE (PART) MEXICAN GEOSYNCLINE ATLANTIC COASTAL 

PLAIN 

(/) NEVADA UTAH UT ~~W C~LEOX~t8o, NEW MEXICO MARYLAND 

LI.J EUROPEAN TEXAS GULF East side South side Anne Arundel and ii:: STAGES COASTAL PLAIN Southeastern part Central Utah Eastern Utah Four Corners area LI.J Animas Mountains Bill Hatchet Peak Prince Georlles~~ (/) Locality 29 Locality 30 Locality 31 Localities 32-36 Locality 40 Locality 41 Locality 42 

1-o: 

LI.Jc( 

<;::: cno: 

~;::: I I ~~~ Mancos 

(part) 

Shale Mancos 

(part) 

Shale Mancos 

(part) 

Shale 

kiL!~ ~!JI 5~ CENO- zct 

~~ Woodbine Baseline Sandstone Raritan Formation Q:(l) MAN IAN ~(/) Formation Upper sandstone LI.J;:) Cowboy Spring JI!II a..o ::::l!::!::! member O..LI.J (!l ?*Dakota Sandstone ? *Dakota Sandstone Q) ? Formation ::::lU c: 

7 ~ *Coal-bearing Washita 'C ? 

*Willow Tank Formation :;; member ~/"-.....,........__?.....___~,_____, 

Group (/) 

;::: (/) '-./""-~ ?- ~ <0 0: LI.J *Patapsco v---. ..----...... ,...,--.. ? _.-.-.,__ _..-._.__ ['-. ]i ? c( *Mojado Formation ii:: ---!'---"?../"'~~ 

I 

*Mojado Formation ':; LI.J 

I 

<0 *Conglomerate 

~ Formation 

ALBIAN (/) Fredericks- 0 (/) member :::;) z burg Group OIT:Q ? ? .e 0 c( 

LI.J LI.J g. u ::t: 0 

~~'1T 1-

c( 

z 

u ~'--""'"~?,./"'~~ ...-..~'-""".C,...--?-.,_...."'-._...."'-._.... ~ LI.J c( tJ 0: ::i: Trinity <0 u 0 U-Bar Formation U-Bar Formation E 0: u ?*Cedar Mountain 0 

LI.J Group Formation ?*Burro Canyon Burro Canyon (part) (part) 0 ~ a.. 

0 APTIAN Formation Formation ...J 

(PART) 

I 

FIGURE 4.-Correlation chart of parts of the Cretaceous System at selected localities in the United States showing rock sequences where Tempskya spp. have 

been reported. Formations containing Tempskya are marked by an asterisk (*). Locality numbers keyed to figure 3 and text. Correlations from Cobban 

and Reeside (1952), Reeside and Cobban (1960), and L. C. Craig (written commun., 1963). 

00 

z 

0 

~ 

1-3 

~ 

> 

~ 

M 

~ H 

(") 

> z 

r.n 

1-0 

M 

(") 

H 

M 

r.n 

0 

~ 

~ ~ 

~ 
OCCURRENCES 9 

Arnold ( 1945, p. 30) reported the occurrence of 

T. grandis in Wheatland County, Mont. Probably 

this specimen also came from the Tempskya-bearing 

zone in the lower part of the Colorado Shale in the 

Musselshell valley, Mont., near locality 5. An additional specimen of Tempskya was obtained from the 

lower part of the Colorado Shale at locality 6 in 

Broadwater County, Mont., by Klepper (1950). The 

strata at the locality are equivalent to the Tempskyabearing Mowry Shale to the south and the shale and 

sandstone member of the Colorado Shale which contains Tempskya several miles to the east. 

Several species of the late Albian fossil N eogastroplites have been identified (Reeside and Cobban, 

1960, p. 17, 21, 27) in the same zone that contains 

Tempskya at localities 4-6 in Montana. Thus, the 

specimens of Tempskya occurring at these localities 

evidently are of late Early Cretaceous (Albian) age. 

WAYAN FORMATION 

Read and Brown (1937, p. 127) reported that 

G. R. Mansfield, W. W. Rubey, and J. S. Williams 

found several specimens of T. minor loose on the 

surface of the Wayan Formation southeast of Grays 

Lake, Idaho, at locality 8. Additional specimens also 

were seen but not collected at locality 9, northwest 

of Grays Lake. It was thought that all the specimens 

were derived from the uppermost part of the Wayan 

Formation. 

Additional collections were made in nearby areas 

at localities 10 and 11 by C. Henry Thomas and 

Henry N. Andrews during the late 1930's and in the 

1940's. Another locality (12) was found about 40 

miles to the northwest. Collections were made here 

during the 1940's by Mr. E. Manion and Mr. H. N. 

Andrews. Andrews (1961, p. 117) believes that at 

this new locality Tempskya occurs in the Wayan 

Formation. The collections of Thomas and Andrews and Manion and Andrews have been discussed 

in several publications (Andrews 1943, 1948, 1961; 

Andrews and Kern, 1947). 

Apparently in all of these localities Tempskya 

spp. are present only in the upper half of the Wayan 

in Rubey's units D and E (Moritz, 1953, p. 68-69). 

Rubey correlated his unit D with the upper part of 

the Bear River Formation of Wyoming and his unit 

E with the Aspen Shale and the basal part of the 

Frontier Formation of Wyoming. Cobban and Reeside (1952a, chart lOb, cols. 62 and 63) showed the 

Wayan as being equivalent to the Aspen Shale and 

the base of the Frontier Formation. 

As shown elsewhere in this report, it has been 

established on the basis of marine faunas that the 

Bear River Formation and the Aspen Shale are of 

late Early Cretaceous (Albian) age. If the stratigraphic correlations between these formations and 

the Tempskya-bearing upper part of the Wayan 

Formation are correct, then the age of that part of 

the Wayan and of the Tempskya spp. in it is also 

late Early Cretaceous (Albian). 

The present writers agree with the statement by 

Read and Brown (1937, p. 127) that 

The finding of Tempskya minor in the Wayan formation only 

40 miles distant from the Aspen localities in Wyoming, in a 

region of relatively similar lithology, indicates a fairly close 

correlation in age, and that the Wayan formation, or a portion of it, may reasonably be regarded as of Colorado age 

and the time equivalent of the Aspen shale of Wyoming. 

ASPEN SHALE 

Idaho.-A specimen of Tempskya sp. was collected 

by W. W. Rubey in 1934 from the Aspen Shale about 

400 feet above the Bear River Formation in eastern 

Idaho at locality 13 (USGS fossil plant loc. 8425 

TBI). Here, as in western Wyoming, the Aspen consists of olive-green and gray-green siliceous shale, 

tan sandstone, porcelanite and greenish siltstone or 

fine-grained sandstone, according to Moritz (1953, 

p. 69) . The Aspen Shale of Idaho is generally considered to be correlative with the Aspen Shale of 

southwestern Wyoming (Cobban and Reeside, 

1952a). The occurrence of Tempskya sp. in the 

Aspen Shale in both Idaho and Wyoming is additional evidence for this correlation. 

In Wyoming, the Aspen Shale is now thought to 

be of late Early Cretaceous (Albian) age .by most 

geologists as discussed below. If the correlation of 

the Aspen Shale in Idaho and Wyoming is justified 

and the current age assignment of the Aspen in 

Wyoming is correct, then it can be concluded that 

the Aspen Shale in Idaho and the specimens of 

Tempskya sp. which occur in it are probably of late 

Early Cretaceous (Albian) age. 

Wyoming.-Several specimens of T. grandis and 

T. minor were collected by W. W. Rubey and J. S. 

Williams during the early 1930's from the Aspen 

Shale at localities 14 and 15 in western Wyoming. 

There is a good exposure of the Aspen Shale and 

adjacent formations in sec. 17, T. 35 N., R. 115 W., 

near locality 14; a generalized section which illustrates the lithology of these rocks was published 

previously (Read and Brown, 1937, p. 126). It shows 

that the Aspen Shale is about 1,200 feet thick in 

this area and consists mainly of gray shale and thin 

beds of gray tuffaceous sandstone. The specimens of 

Tempskya occur in the lower part of the Aspen 
10 NORTH AMERICAN SPECIES OF TEMPSKY A 

approximately 400 feet above the Bear River Formation. 

Other examples of Tempskya have been obtained 

from the Aspen Shale in western and southwestern 

Wyoming at localities 16-18 by Rubey during the 

1950's. He and Reeside also collected specimens from 

a porcelanite bed at localities 19 and 20 that they 

consider to be a nearshore equivalent of the Aspen 

Shale. 

Several specimens of Tempskya have been collected in southwestern Wyoming near locality 21 by 

Rubey and Reeside in 1949 and at locality 22 by 

H. R. Christner in 1950. Here they were found in 

strata which have been referred to the basal part of 

of the Frontier by Cobban and Reeside (1952b). 

Rubey, however, preferred to place these strata in 

the Aspen Shale (written commun., 1961). Judging 

by the other occurrences of Tempskya in the Aspen 

Shale of nearby areas, the writers agree with Rubey 

and would prefer to consider the strata in question 

as the upper part of the Aspen Shale rather than 

basal Frontier. 

The Aspen Shale was considered to be of early 

Late Cretaceous (Cenomanian) age until 1951. In 

that year, Cobban and Reeside (1951) demonstrated 

that the impressions and crushed internal molds of 

ammonites that occur in the Aspen and other formations in the western United States had been misidentified. Actually the fossils belong to genera that 

are apparently of late Early Cretaceous (Albian) 

age. Thus, the Aspen and certain other formations 

in the western interior of the United States were 

classified as probably of late Early Cretaceous age. 

Yen (1952, p. 757, 764) disagreed with the age revision because he identified fresh-water mollusks 

that he considered to be of early Late Cretaceous 

(Cenomanian) age in the· underlying Bear River 

Formation. Nevertheless, Cobban and Reeside have 

continued to argue for a late Early Cretaceous age 

for the Aspen, although they recognize that it might 

possibly be of early Late Cretaceous (Cenomanian) 

age (Cobban and Reeside, 1952a; Reeside and Cobban, 1960; Moritz, 1953, p. 69). At any rate, the 

Aspen Shale now is generally regarded as being of 

late Early Cretaceous (Albian) age. Thus, the specimens of Tempskya sp. occurring in the Aspen are 

also of latest Early Cretaceous (Albian) age. 

THERM:OPOLIS SHALE 

A specimen of Tempskya mino1· was collected 

from the Thermopolis Shale in the Powder River 

valley area of Wyoming at locality 26 by C. H. 

Wegemann in 1910 (Read and Brown, 1937, p. 127). 

It was associated with a coal bed 25 feet below the 

base of the overlying Mowry Shale and in a unit just 

above the Muddy Sandstone Member of the Thermopolis, which is sometimes included in the Mowry 

(Reeside and Cobban, 1960, p. 4). Another specimen of Tempskya was collected about 35 miles northeast of Medicine Bow, Wyo., at locality 27 by B. W. 

Siegmund in 1939. He indicated that the specimen 

came from a gray shale bed. The Thermopolis Shale 

is exposed in this area and does contain Tempskya 

about 100 miles to the north at locality 26 in the 

Powder River area, so it is assumed that the 

Tempskya at locality 27 probably came from the 

Thermopolis. 

Until recently the Thermopolis Shale was thought 

to be of early Late Cretaceous age. However, the 

recognition of the probable late Early Cretaceous 

ammonite N eogastroplites in it at several localities 

has recently caused geologists to regard it as Albian 

(Cobban and Reeside, 1951, p, 1893; Reeside and 

Cobban, 1960, p. 48-49). This age assignment is 

supported by the discovery of arenaceous Foraminifera in the Thermopolis as reported by Eicher (1958, 

p. 80-81). He found that the previously described 

species that occur in the shale below the Muddy 

Sandstone Member of the Thermopolis had been 

reported from rocks of late Early Cretaceous age in 

Kansas, Texas, Alaska, and western Canada. Some 

of the species in the shale overlying the Muddy 

Sandstone Member are known only from rocks of 

late Early Cretaceous age in Alaska and western 

Canada. Skolnick (1958a, b) ha,s described an assemblage of Early Cretaceous Foraminifera in the Newcastle Sandstone and the Skull Creek Shale, which 

are equivalent to the Thermopolis, and in the lower 

part of the Mowry Shale, which overlies the Thermopolis Shale. Thus, it can be concluded that the 

Thermopolis Shale in the Powder River valley and 

the specimens of Tempskya occurring in it at locality 26 and possibly at locality 27 are of late Early 

Cretaceous (Albian) age. 

WILLOW TANK FORMATION 

In 1934, fragments of silicified plant material collected from the Overton Fanglomerate of southeastern Nevada at locality 29 by Eugene Callaghan and 

W. W. Rubey were identified by R. W. Brown as 

Tempskya sp. In 1937, these fragments were referred to the new species T. minor by Read and 

Brown. They were obtained from a bed of gray clay 

about 100 feet thick that overlies a thin conglomerate in the lower part of the Overton, 6 miles south-
OCCURRENCES 11 

west of Kaolin, Nev. (Rubey and Callaghan, 1936, 

p. 121). The remains of another fern Microtaenia 

paucifolia were found several hundred feet above 

the zone containing Tempskya. Such fern fronds are 

known elsewhere only in the Aspen and Frontier 

Formations. Originally the entire thickness of the 

Overton had been considered of probable Tertiary 

age by Longwell (1928, p. 89). However, on the 

basis of the specimens of T. minor and Microtaenia 

paucifolia, both of which were known only from 

what was thought at that time to be the lower to 

middle part of the Upper Cretaceous, the lower part 

of the Overton was classified as of early or middle 

Late Cretaceous age (Rubey and Callaghan, 1936, 

p. 121-122; Read and Brown, 1937, p. 127). 

Subsequently, Longwell (1949) divided the lower 

half of the Overton into two formations, applying 

the name Willow Tank to the lower formation, which 

includes the Tempskya-bearing zone, and the name 

Baseline Sandstone to the overlying formation, 

which- contains Microtaenia paucifolia near the base. 

The name Overton Fanglomerate was retained for 

only the upper half of the original Overton. An additional collection of fossHs was obtained from the 

Willow Tank Formation by Longwell, who submitted 

it to John B. Reeside, Jr., for study. The following 

forms were identified by him: 

Unio aff. U. hamili McLearn and U. vetustus Meek 

Unio sp., fragments of a large oval form 

Diplodon? n. sp. 

M usculiopsis? sp. 

Viviparus cf. V. montanensis Stanton 

Lioplax? cf. L.? endlichi (White) and Coniobasis O'rfmanni 

Stanton 

Melampus? cf. M. caurinus McLearn 

Physa cf. P. usitata White 

Lymnaea (Pleurolimnaea) n. sp. 

Planorbis ( Gyraulus) cf. P. p'raecursor·is White 

Helix? sp; 

Cyprid ostracodes, several species 

Fish teeth and bones 

Fruits of Chara or a related plant 

Reeside (written commun., 1956) stated: 

The most significant specimens are two beak fragments of 

a corrugated Unio· that belongs to a type we have not had 

above the Bear River, i.e., early Upper Cretaceous. ':' ':' ':' My 

best judgment of the age of the beds, based on the fauna alone, 

is that they are not younger than early Upper Cretaceous and 

might be as old as the Lower Cretaceous beds at Eureka, 

Nevada. However, the Tempskya argues strongly for early 

Upper Cretaceous. The assemblage, incidentally, is that of a 

quiet pond. 

R. E. Peck (written commun., 1956) identified 

the fossil fruits of Chara and related plants collected 

by Longwell and concluded that the Chara-bearing 

bed 

is pretty close to Bear River in age. My conclusion is based 

on the occurrence of Aclistochara mundula Peck-range, Upper 

and Lower Cretac,eous, abundant throughout the Gannett 

group, upper part of the Kootenai, and Bear River, especially 

characteristic of the Bear River; Chara cf. C. stantoni Knowlton 

-C. stan toni is known only from the Bear River; numerous 

specimens of a species of Metacypris that are also found in 

the Gannett group and Bear River. 

Peck (1957) has confirmed these stratigraphic 

occurrences of the fruits of Chara and related plants. 

In summary, the fossils indicate that the Willow 

Tank Formation is probably equivalent to the Bear 

River and possibly to older formations, and that the 

lower part of the overlying Baseline Srandstone is 

equivalent to the younger Aspen Shale and Frontier 

Formation. Following the findings of the paleontologists, Longwell classified the Willow Tank Formation 

and the Baseline Sandstone as of Late Cretaceous 

age and the restricted Overton Fanglomerate as of 

early Cenozoic or Late Cretaceous age. 

Since the work of Longwell, the Bear River Formation and the Aspen Shale have been reclassified 

as of late Early Cretaceous age (Albian) by Cobban 

and Reeside (1952a), and Rees.ide and Cobban 

(1960). Therefore, it can be concluded that the 

T-empskya-bearing Willow Tank Formation, which 

has been correlated with the Bear River, is of late 

Early Cretaceous age and that the specimens of 

Tempskya minor· found in that formation are also 

of that age. 

CEDAR MOUNTAIN FORMATION 

Specimens of Tempskya have been collected from 

the Cedar Mountain Formation near the type locality of that formation in central Utah at locality 30 

by W. L. Stokes (1944) and P. J. Katich, Jr. (1951). 

Those collected by Katich (1951, p. 2094) were 

identified only as Tempskya sp., whereas those collected by Stokes ( 1952, p. 17 69) were identified 

tentatively as T. minor. More recently, Tidwell and 

Hebbert (1972) have discussed the occurrence of 

Tempskya in the Cedar Mountain near locality 30. 

The Cedar Mountain Formation contains a few 

other fossils besides Tempskya, such as bone fragments of dinosaurs and other vertebrates, freshwater ostracodes, pelecypods, gastropods, and several plant fossils. Peck examined some of the fossils 

and came to the following conclusions regarding the 

ostracodes and the charophytes, as quoted by Stokes 

(1952, p. 1768): 

All of th2se are common fossils in the Gannett group, the 

Cloverly of northwestern Wyoming, and the limestones in the 

upper Kootenai of Montana. Clavator harrisi is common in the 

Trinity of the Gulf coast. None of these species occurs in the 

Morrison of the Front Range in Colorado, in eastern Wyoming, 
12 NORTH AMERICAN SPECIES OF TEMPSKY A 

or in the Black Hills. Their occurrence is an excellent indication of the Lower Cretaceous age of the formation. 

Eupora onestae, a pelecypod of Aptian Age, which 

has been found in the Cedar Mountain is very common in the Kootenai Formation of Montana, according to Cobban (Katich, 1951, p. 2093). 

Thus it is apparent that the Cedar Mountain is of 

Early ·Cretaceous age and correlates, at least in part, 

with the Kootenai Formation, Gannett Group, and 

Cloverly Formation of Wyoming and Montana. 

There is a question in regard to the part of the Early 

Cretaceous with which the Cedar Mountain correlates. The presence of Tempskya argues for a late 

Early Cretaceous (Albian) age, whereas the pelecypod, charophytes, and ostracodes suggest a middle 

Early Cretaceous (Aptian) age for the formation. 

At present, the authors regard the upper part of 

the Cedar Mountain as being of Albian Age and the 

lower part, of Aptian Age. They recognize, however, that the range of Tempskya may be longer 

than now thought and may include a part of Aptian 

time as suggested by the age of the other fossils in 

the Cedar Mountain Formation. 

BURRO CANYON FORMATION 

Specimens of an unidentified species of Tempskya 

have been collected from the upper part of the 

Burro Canyon Formation at locality 31 northwest 

of Moab, Utah (McKnight and Rigby, 1963). The 

fern is represented by many fragments, including 

several that resemble the holotype of T. knowltoni 

in external morphology. The Burro Canyon Formation is generally considered to be of Early Cretaceous age, but there is some question about its 

exact position within that part of the Cretaceous. A 

few additional fossils have been identified from the 

formation (Shawe. and others, 1968, p. A73), of 

which the most significant for our purposes are the 

pelecypods Protelliptio douglassi Stanton and Lampsilis farri Stanton. They "are well known and widespread Early Cretaceous (Aptian) species," according to Shaw·e, Simmons, and Archbold (1968, 

p. A73). The presence of Tempskya sp. in the upper 

part of the formation suggests to the authors of this 

report that at least the upper p~art of the Burro 

Canyon Form,ation is probably Albian in age. 

DAKOTA SANDSTONE 

Utah.-Specimens of Tempskya sp. were collected 

in San Juan County, Utah, at locality 32 by C. B. 

Read during 1943. The specimens came from the 

middle coal-bearing member of the Dakota Sandstone. 

Read and Brown (1937, p. 127) described the 

occurrence of Tempskya in the La Sal Mountains 

of Utah at locality 33 as follows: 

Frank L. Hess, of the United States Bureau of Mines, during an investigation of the carnotite deposits in the region of 

the La Sal Mountains, Utah, found a specimen of Tempskya 

lying in the soil on deposits overlying the Upper Jurassic 

Morrison formation (McElmo of some reports). The locality 

is on the divide southwest of Winburn's ranch, near the head 

and on the northwest side of Pack Creek, just west of Mount 

Peale in the La Sal Mountains. As the specimen came from 

deposits above the Morrison, its source must lie between the 

Cretaceous Dakota ( ?) sandstone and the Mancos shale. The 

Mancos shale is a dark marine shale deposit and is not likely 

to have contained the Tempskya. There remains the relatively 

thin deposit of light-colored Dakota ( ? ) sandstone about 40 

feet), which, however, Hess did not distinguish as a separate 

unit in the section at the time of his visit. The outcrop of the 

Dakota ( ? ) thickens and thins considerably in this area because its top was greatly eroded before the first deposits of 

the Mancos were laid down. It appears probable, therefore, 

that the Dakota<?) was the source of the Tempskya collected 

by Hess. 

The locality (loc. 32) at which Read collected 

Tempskya is about 15 miles south of the area in 

which Hess made his collection. Therefore, judging 

by the nearness of the two localities, the Hess specimen probably also came from the middle coal-bearing member of the Dakota Sandstone. 

During 1944, W. L. Stokes collected a specimen of 

Tempskya knowltoni from the lower part of the 

Dakota Sandstone at locality 34 in Grand County. 

The specimen was described and illustrated by 

Brown in 1950. 

Colorado.-A specimen of Tempskya was collected 

in Montezuma County, Colo., at locality 35 by R. 

Clare Coffin. Although its stratigraphic position is 

unknown, it probably came from the middle coalbearing member of the Dakota Sandstone, which is 

known to contain Tempskya elsewhere on the Colorado Plateau. 

New Mexico.-In 1956, J.D. Strobell reported the 

occurrence of Tempskya in the basal beds of the 

Dakota Sandstone in northwestern New Mexico at 

locality 36. In 1961, Strobell and Read returned to 

the locality and made additional collections of Tempskya. A stratigraphic section of the rocks exposed 

at this locality is as follows: 

Section of Dakota Sandstone 6 miles north of Bitlabito Tt·ading Post, San Juan County, N.Mex., in E%SE1

4 sec. 1, T. 

31 N., R. 21 W., Pastora Peak quadrangle 

[Measured by J.D. Strobell, Sept. 1961] 

Top of section, top of pediment. 

19. Covered by pediment gravel float. Consists of 

Mancos Shale and pediment gravel. Laterally 

to the south on the east and west sides of 

Feet 

this ridge Mancos Shale is exposed and 

Gryphaea shells are abundant----------------- 20 
OCCURRENCES 13 

Section of Dakota Sandstone 6 miles north of Bitlabito Tradin,g 

Post, San Juan County, N.Mex., in E%SE1)~ sec. 1, T. 31 N., 

R. 21 W., Pastora Peak quad?·angle-Continued 

Dakota Sandstone: 

18. Sandstone, crosslaminated, ripple-marked; has 

more marine aspect than the lower sandFeet 

stones ----------------------------------- 4 

17. Covered, dark-gray shale exposed by digging _ 7 

16. Sandstone and sandy shale, forms cliff 

laterally --------------------------------- 7 

15. Gray to black carbonaceous shale, lower part 

covered ---------------------------------- 15 

14. Sandstone and sandy claystone ------------- 5 

13. Coaly black shale containing thin beds of 

very fine grained white sandstone bearing root 

casts (like ganister) ---------------------- 23 

12. Covered interval containing 2-ft bed of sandstone at top; coaly shale exposed by digging 

in lower part ----------------------------- 11 

11. Sandstone, thin-bedded, platy, poorly sorted _ 2 

10. Shale, sandy, greenish-gray, passing laterally 

into coaly shale, and containing some beds; of 

sandstone 1 to 2 ft thick -------------------- 6 

9. Sandstone and coarse conglomerate, containing 

silicified wood and plant impressions. This 

ledge caps the cliff and contras:ts with the 

lighter colored underlying unit. Traced lateralJy it range's from 2 ~to 8 ft in thickness 

and forms a broad bench to the south where 

Tempskya was found in it in NW%NW%, 

sec. 12, T. 31 N., R. 21 W. (USGS fossil 

plant loc. 9787) --------------------------- 6 

Total Dakota Sands,tone ------------- 86 

Morrison Formation: 

8. Sandstone, weathers light with greenish cast, 

fine-grained, clayey, limonitic; forms cliff below the thin dark resistant basal ledge of 

the Dakota Sandstone --------------------- 20 

7. Claystone, dark-gray, weathers pale green __ 

6. Sandstone, thin-bedded, crosslaminated, lighttan --------------------------------------

5. Claystone, sandy, some tendency to weather 

puffy, weathers pale greenish; two thin beds 

3 

2 

of sandstone near top ---------------------- 6 

4. Conglomeratic sandstone, light-tan, matrix 

fine grained and clayey, pebbles mostly less 

than 1 inch, few as much as 2 inches, in 

middle part of unit; some angular red chert 

pebbles one-fourth to one-half inch possibly 

from underlying Brushy Basin Shale Member; 

fluvial type of crossbedding ---------------- 5 

3. Claystone, dark-gray, greenish-weathering, 

very argillaceous and not at all puffy like 

next unit below -------------------------- 21 

(Units 3 through 8, 57 feet thick, may represent the Burro Canyon Formation.) 

2. Puffy bentonitic light-gray claystone and 

siltstone; thickness estimated -------------- 30 

1. Bright-red silty claystone, somewhat bentonitic and puffy, not measured. 

Base of measurements, not base of exposures. 

The lower two members of the Dakota Sandstone 

on the Colorado Plateau were considered to be of 

middle Early Cretaceous (Aptian) age by Cobban 

and Reeside (1952a). However, the finding of 

Tempskya in the middle coal-bearing member of the 

Dakota suggests to the authors that at least a part 

of this member is of Albian Age. 

MEXICAN GEOSYNCLINE 

MOJADO FORMATION 

The two new species of Tempskya described in 

this paper, Tempskya reesidei and Tempskya zelleri, 

occur in the Mojado Formation 1 southwest of Deming, N. Mex., at localities 40 and 41. Details of the 

stratigraphy of the occurrences and lists of the 

marine fossils associated with Tempskya are given 

in the part of this report written by Zeller, so only 

the following brief summary is given here. 

The mollusks, smaller Foraminifera, and gastropods found in rocks above and below those containing Tempskya were examined by several paleontologists. From their findings, it is apparent that the 

part of the Mojado Formation that contains the 

marine fossils ~and Tempskya is of late Fredericksburg (middle Albian) to late Washita (late Albian) 

age. 

ATLANTIC COASTAL PLAIN 

PATAPSCO FORMATION 

Specimens of the first American Tempskya to be 

described, T. whitei Berry, were collected at locality 

42 in the valleys of Stony Run and Deep Run, southeast of Annapolis, Anne Arundel County, Md. The 

type specimen and others are from the Patapsco 

Formation which, in the Maryland Geological Survey's volume on the Lower Cretaceous (Clark and 

others, 1911), was classed as the uppermost formation of the Potomac Group (Lower Cretaceous). 

E. W. Berry, in discussing the age of the relatively 

large flora of the Patapsco Formation, said (1911a, 

p. 160): 

Moreover, the latter flora [Albian of Portugal] closely 

parallels the Patapsco, in that both mark the fir8t abundant 

appearance of undoubted dicotyledons and a persistence of 

a considerable number of the earlier Cretaceous types, which 

survive in both the Patapsco flora and that of the Albian of 

Portugal. 

On the basis of this close similarity between these two 

floras on opposite sides of the Atlantic, and the fact that 

both mark the first abundant appearance of Dicotyledonae, 

and the further fact that the Patapsco formation is overlain unconformably by the Raritan formation, carrying an 

abundant and unmistakably Cenomanian flora, the Patapsco 

formation is considered of Albian age. The unconformity 

which separates the Patapsco formation from the underlying 

1 1'his name as formally used by Zeller (1958c) is herewith adopted for usage by the U.S. Geological Survey. 
14 NORTH AMERICAN SPECIES OF TEMPSKY.4 

Potomac beds is believed to represent all or ne:arly all of 

the time interval represented by the Aptian stage of European geology. 

Apparently, until 1948, there was general agreement in regard to the Early Cretaceous age of the 

three units of the Potomac Group. However, in that 

year Anderson (1948, p. 14-16, 23, 84-85, 92-94, 

97-102) and Vokes (1948, p. 129-133) suggested 

that the two upper units of the Potomac Group, the 

Arundel and the Patapsco Formations, a:re of early 

Late Cretaceous (Cenomanian) age. As evidence, 

they cited marine mollusks obtained from a well 

core, correlation from the well to the outcrops by 

means of heavy-mineral studies, and reevaluation 

of certain old data. Dorf reviewed all the evidence in 

1952 and concluded that such an age assignment was 

unsubstantiated because (p. 2176) : 

1. The invertebrate fossils from the Maryland Esso well, 

dated as Cenomanian by Vokes, were recovered from 

sediments which cannot be definitely correlated on a 

lithologic basis with either the true Arundel or Patapsco 

formations along the outcrop. 

2. The age of the subsurface beds, referred to as the "Patapsco-Arundel section," is not necessarily the same as 

the age of the true Arundel and Patapsco formations 

along the outcrop. 

3. Organic remains, both floral and faunal, collected from 

along the outcrop of the Arundel and Patapsco formations indicate that these formations are more reasonably assignable to the Lower Gre,taceous series, not 

the Upper Cretaceous. 

Spangler and Peterson (1950) also assigned a 

Late Cretaceous age to the Arundel and Patapsco 

Formations on the basis of some sauropod remains 

that had been found in the Arundel. However, Dorf 

(1952, p. 2177) stated that "Present-day authoritative opinion still maintains that the Arundel vertebrate fauna is Early Cretaceous***." 

A reanalysis of the Potomac Group floras was 

made by Dorf, who concluded (1952, p. 2177) that 

"the Patuxent and Arundel floras are essentially 

similar associations comparable in age and composition with the Wealden flora of England, which 

is at present considered of N eocomian age. The 

Patapsco flora *** appears to be comparable in age 

and composition with the Albian floras of Portugal." 

Although the Maryland Department of Geology, 

Mines, and Water Resources has accepted Anderson 

and Vokes' proposed age reclassification of the 

Patapsco and Arundel Formations, others, including 

the U.S. Geological Survey, continue to consider the 

Potomac and Arundel to be of Early Cretaceous age 

(Richards and others, 1957). The authors of this 

account also consider the Tempskya-bearing part of 

the Patapsco Formation to be of latest Early Cretaceous (Albian) age. 

REWORKED SPECIMENS 

Arizona.-A waterworn specimen of Tempskya 

sp. was collected in 1950 by Phil F. Van Cleave, 

Chief Naturalist, Petrified Forest National Park, 

from a gravel bed exposed just above the Moenkopi Sandstone near Holbrook, Ariz., at locality 

37 (R). These gravels are probably of middle Pleistocene age and consist of material derived from all the 

formations in the area drained by the Little Colorado River, according to Maurice E. Cooley (written 

commun., 1962). Thus, the original source could 

have been the Dakota Sandstone of Early Cretaceous age which is widely exposed in the drainage area 

of the Little Colorado. 

Nebraska.-Mr. N. H. Niles has collected four 

fragments of Tempskya sp. from loose boulders 

eroded from the Chadron Formation of Oligocene 

age in Dawes County, Nebr., at locality 28 (R). In 

addition to Tempskya, fragments of other plants including Cycadeoidea have also been found among the 

boulders. All the boulders, including the specimens 

of petrified wood, are well rounded, indicating that 

they have probably been transported by streams for 

a considerable distance before they were deposited 

in the Chadron. 

Arnold (1958, p. 134), who described this occurrence and the specimens of Tempskya sp., believed 

that "these silicified plants were eroded from the 

Lakota Sandstone during the early part of the 

Oligocene Epoch and that they were carried [from 

the area of the hogback of Lakota around the Black 

Hills] by swift streams over the intervening 50 

miles to the site where they were found." He suggested that the Lakota is the source, because in the 

Black Hills it contains cycadeoids that are also 

silicified. However, the specimens found in N ebrwska may have been derived instead from the 

lower part of the Graneros Shale which is exposed 

along the south rim of the Black Hills and is a time 

equivalent of the Aspen Shale, Thermopolis Shale, 

and other formations that elsewhere contain Tempskya. 

New Mexico.-A small specimen of Tempskya sp. 

was collected by L. F. Brady during the early 1940's 

from the gravel beds of Quaternary age about a 

mile and a half northeast of Grants, N. Mex., at 

locality 38 (R). The gravels consist mostly of material derived from the conglomerate in the lower 

part of the Chinle Formation (Upper Triassic). 

However, the specimen of Tempskya probably came 

from the part of Dakota Sandstone of Early Cretaceous age which is well exposed within a mile or 
OCCURRENCES 15 

less of the collecting locality. This part of the 

Dakota is known to contain Tempskya sp. about 150 

miles northwest of Grants. The specimen was originally identified by R. W. Chaney and is now in the 

collections of the Museum of Northern Arizona at 

Flagstaff, Ariz. 

At least one specimen of Tempskya sp. has also 

been collected from stream gravel in the valley of 

Rio Puerco about 30 miles northwest of Albuquerque 

at locality 39 (R). The precise locality is not clear 

because the specimen was found by an amateur rock 

collectcr. The gravels of the Rio Puerco valley contain abundant petrified plant material derived from 

several formations ranging in age from Late Jurassic to Paleocene. Strata assigned to the Dakota 

Formation are present and are known to contain 

petrified plant material. However, the Mesaverde 

and some of the Paleocene rocks also contain plants. 

It can only be surmised that the material is from 

the Dakota. 

North Carolina.-The new specimens of Tempskya reported from North Carolina by West ( 1968, 

1970) came from what are probably Quaternary 

gravel deposits. Although the specimens are undoubtedly reworked, they are of some note because 

they constitute the second reported occurrence of 

Tempskya east of the Mississippi River. The position 

of these localities is not shown on the index map 

(fig. 3). 

Oregon.-ln 1914, J. T. Pardee collected two specimens of Tempskya from the gravels in a placer pit 

on Lightning Creek, 1 mile north of Greenhorn, 

Baker County, Ore., at locality 7 (R). Additional 

specimens of Tempskya sp. have been obtained by 

members of the Oregon Geological Survey and others 

in the vicinity of this locality in both Baker and 

Grant Counties from this same placer deposit. Apparently these gravels are also the source of the 

specimens of Tempskya sp. that are so highly prized 

by local rock collectors. The age of the placer deposit 

has not been established but appears to be of preMascal (Miocene) age. 

Very little is known about Cretaceous stratigraphy in this general area. Therefore it can only be 

suggested that the material may have been initially 

derived from Cretaceous rocks, and, judging by the 

abundance of material, the source was probably not 

too distant. 

Wyoming.-Read and Brown (1937, p. 127) reported the finding of a specimen of Tempskya in 

terrace gravels in southwestern Wyoming at locality 

23 (R), as follows: 

One small water-worn specimen of Tempskya minor was 

colleded by R. W. Brown in June, 1930 from a grave:l terrace 

in the valley of the westward-flowing Twin Creek near the 

town of Foss:il, in T. 21 N., R. 117 W., Wyoming. * * * The 

debris of this gravel terrace includes, besides other rocks, 

some pebbles of igneous rock, no outcrop of which occurs 

within the present drainage basin of Twin Creek. The gravel 

ha~ therefore not been derived entirely from the Tertiary 

bedrock on which it lies, but a portion must have come from 

some exterior source. The specimen of Tempskya, if the 

diagnosis of the stratigraphic significance of the species is 

correct, came from Cretaceous deposits. * * * The nearest 

are,a of outcrop of such deposits to the point where the 

specimen was found is across the low divide and in the townships next to the east, where Bear River, Aspen, and Frontier 

beds occur just east of Kemmerer. The inference that the 

specimen came from this area s,eems to be reasonable, but 

it involves the necessity of explaining some changes in 

drainage which the writers believe have taken place but 

the elucidation of which they deem not within their present 

undertaking. 

Arnold (1945, p. 30-31) described the occurrence 

of Termpskya wyomingensis in northern Wyoming 

at locality 25 (R). Here the specimens were found 

on the valley floors of Beaver Creek and its tributaries northeast of Greybull, Big Horn County, Wyo. 

Although the source of the specimens has not been 

determined, Arnold mentioned that they only occur 

where the Morrison Formation is exposed in the 

area and that they are usually associated with 

dinosaur bone fragments, ga:stroliths, and occasional cycad fragments. The authors of this paper 

suggest that the Mowry Shale or Thermopolis Shale 

is also a possible source of T. wyomingensis at this 

locality, as both formations are exposed in the area. 

The intervening Cloverly Formation also could be 

the source, as it also is exposed in the area and 

locally contains plants. 

Several small specimens of petrified material, reportedly resembling Tempskya, have been collected 

from a conglomerate of Late Cretaceous age in the 

Jackson Hole area at locality 24 (R) (Love and 

others, 1948, p. 25). The conglomerate underlies the 

Pinyon Conglomerate of Paleocene age and has been 

referred to the Mesaverde Group by Foster (1947). 

However, the specimens of plant material and the 

pebbles in the conglomerate are well rounded to 

subangular and obviously have been reworked from 

older formations. The Ternpskya specimens may 

have been derived from either the Mowry Shale or 

Thermopolis Shale which are exposed in the area 

and which contain Tempskya elsewhere. 
16 NORTH AMERICAN SPECIES OF TEMPSKY A 

STRATIGRAPHY AND AGE OF THE TEMPSKYABEARING ROCKS OF SOUTHERN HIDALGO 

COUNTY, NEW MEXICO 

By ROBERT A. ZELLER, JR. 

INTRODUCTION 

The specimens of Tempskya discovered in southern Hidalgo County, N. Mex. (fig. 5), by the author 

108 °45' 

32°00' 

Tempskya locality 

(9703) 

0 

30' 

are closely associated with an Early Cretaceous 

marine fauna that is rich in short-ranging fossils, 

the stratigraphic distributions of which have been 

accurately established in terms of both the Texas 

Coastal Plain and European sequences. Such an 

opportunity to date plant fossils by using a marine 

fauna is ~are; therefore, the biota is of fundamental 

importance in establishing the age of Tempskya. 

0 

108°00' 

VICTORIO 

36° 1-----+---+------+--t 

I 

I 

I NEW MEXICO 

34°~-~---+---+-~ 

31 °30'JS..---ij--_,--~~-=-----=-:::c-::--==-~~+------iF---=--~~~~~D;:;-;O~G;-M~O;::;;U-;r;N:iTT-aiAI~NS. ~ 

0 I I I I 

0 

I I I I I 

5 

5 

I I 

10 

I 

I 

~, I a I 

\0\{_'' ~ 0 i 

-z.A c? I ~-z-"' I 

- ----__l_...j 

10 15 MILES I I 

I 

15 KILOMErRES 

CONTOUR INTERVAL 1000 FEET 

DATUM IS MEAN SEA LEVEL 

EXPLANATION 

.. 

Mojado Formation 

9702 

USGS fossil plant locality 

I--ll 

Type section of Cretaceous formation 

4, Cowboy Spring Formation 

3, Mojado Formation 

2, U Bar Formation 

1. Hell-to-Finish Formation 

FIGURE 5.-Location of the known exposures of the Mojado Formation, known Tempskya localities, and the type sections of 

the several Cretaceous formations mentioned in this report. 
TEMPSKY A-BEARING ROCKS OF SOUTHERN HIDALGO COUNTY 17 

This chapter summarizes the stratigraphy of the 

Moj ado Form·ation and presents marine fossil evidence regarding the age of the formation and the 

fossil fern Tempskya. 

Prior to my work, few geologic studies had been 

made in southern Hidalgo County. Darton (1928a, b) 

recognized the existence of rocks of Early Cretaceous age in the region, and Lasky (1947) studied the 

Lower Cretaceous rocks of the Little Hatchet Mountains. 

The writer began detailed geologic mapping and 

stratigra,phic study of the rocks in the Big Hatchet 

Peak quadrangle, Hidalgo County, N. Mex., in 1951. 

The project was eventuaily enlarged to include detailed and reconnaissance geologic mapping throughout mast of southern Hidalgo County and study of 

the stratigraphy of the Cretaceous System in much 

of southwestern New Mexico and adjoining areas in 

Arizona, Texas, and Mexico. Results of this work 

have been published in several reports (Zeiler and 

Read, 1956; Dane and Bachman, 1961; Zeiler, 

1958a, b, c; 1965: Zeiler and Alper, 1965). 

CRETACEOUS ~TRATIGRAPHY 

Lasky (1947) divided the stratified Lower Cretaceous rocks of the Little H:atchet Mountains into 

seven formations. As they could not be correlated 

with described formations elsewhere in the region, 

he gave them new names. 

South of the Little Hatchet Mountains, the Lower 

Cretaceous rocks are divisible into three formations, 

but as they cannot be correlated at present with the 

formations in the Little Hatchet Mountains, only 20 

miles to the north, or with any other described 

formations in the region, the writer has given them 

new names (Zeiler, 1958c). In a1scending order they 

are the Heil-to-Finish Formation,:! U-Bar Formation, 2 and Mojado Formation. The three names have 

been used by Dane and Bachman (1961), and the 

units later were described in detail by Zeiler (1965). 

Along the east flank of the Animas Mountains 

west of the Big Hatchets, the U-Bar and Mojado 

Formations are recognized. However, because of 

local erosion during earliest Cretaceous time, the 

Heil-to-Finish Form~ation is missing, and the U-Bar 

Formation is thin and rests upon deeply eroded 

Permian rocks. Here the Mojado Formation is overlain conformably by another formation of Early or 

Late Cretaceous age, the Cowboy Spring Formation,2 

which was described in detail in a report on the 

geology of the Walnut Wells quadrangle by Zeller 

and Alper (1965). 

2 This name is herein adopted for usage by the U.S. Geological Survey. 

Hell-to-Finish Formation.-The Hell-to-Finish 

Formation, named for a stock tank, is exposed in a 

limited area on the southern fl·ank of the Big Hratchet 

Mountains. The type section is in sees. 2 and 11, 

T. 32 S., R. 15 W. It rests with erosional unconformity upon carbonate rocks of Permian age and is overlain conformably by the U -Bar Formation. Rock 

types are primarily red shale and arkosic sandstone. 

A 30-foot basal bed of conglomerate is composed of 

chert pebbles derived from the underlying Permian 

strata. The formation has a measured thickness of 

1,27 4 feet in the type section where it is most completely exposed. The rocks are relatively nanresistant, and elsewhere thicknesses cannot be determined. The age of the Hell-to-Finish is not definitely 

known because of the lack of fos,sils. However, it is 

believed to be of Early Cretaceous age because the 

upper beds are transitional with the lowest strata 

of the U-Bar Formation, which is known to be of 

Early Cretaceous age. 

U-Bar FoTmation.-This unit is named for U-Bar 

Ridge, a prominent arcuate ridge southwest of the 

Big Hatchet Mountains; it is the erosional remnant 

of a resistant limestone reef folded into a broad 

syncline. The type section is a composite of several 

sections, but the main exposure~ are on the northwestern part of U-Bar Ridge. The formation consists 

mostly of marine limestone. The lower and middle 

parts are thin-bedded fossiliferous limestone with 

some thin beds of claystone; the upper part is massive reeflike limestone which is 500 feet thick on the 

northern part of U-Bar Ridge and which thins 

southeastward. Thin limestone beds above the reef 

form the uppermost part of the formation, and these 

are interbedded in a transition zone with sandstone 

typical of the overlying Moj ado Formation. The 

total thickness of the formation in the type area is 

about 3,500 feet, and 6 miles t() the southeast a 

similar thickness has been noted. In Sierra Rica 

(fig. 5) only the upper part of the formation is 

exposed. In the central Anim,as Mountains, the 

U-Bar Formation is thinner than in the composite 

type section and rests unconformably upon Permian 

rocks. Marine invertebrate fossils indicate a late 

Aptian Age for the lower part of the formation, an 

early to middle Albian Age (Glen Rose) for the 

middle part, and a middle Albian Age (Fredericksburg) for the uppermost beds including the reef. 

M ojado Formation.-This unit is named for 

Moj ado Pass, which is the broad low area between 

the main mass of the Big Hatchet and the Alamo 

Hueco Mountains. The type section is south of the 

Big Hatchet Mountains along the north flank of the 
18 NORTH AMERICAN SPECIES OF TEMPSKY A 

low hill in sec. 20, T. 32 S., R. 15 W., and has a 

measured thickness of 5,195 feet. Here the unit can 

be divided into two parts, the lower consisting of 

4,110 feet of nearly unfossiliferous sandstone and 

shale, and the upper composed of 1,085 feet of sandstone and shale and a few thin beds of impure and 

coquina limestone and calcareous sandstone rich in 

marine fossils. The formation has also been recognized northeast of the Big Hatchets in Sierra Rica 

and west of the Big Hatchets in the Animas Mountains. The age of the Moj ado probably extends 

through most of Fredericksburg (middle Albian) 

time and nearly all of Washita (late Albian) time, 

although the ages of the base and top of the formation are not precisely known. 

In the lower part of the formation sandstone 

occurs in fairly thin lensing beds. Its crosslamination 

is pronounced. Its fresh color is gray, and its 

weathered color, though predominantly brown, 

ranges from white through many shades of brown, 

depending upon various concentrations of limonitic 

pigment. Sand grains are angular to subangular and 

medium to fine. Most of the sandstones are composed almost entirely of quartz grains, but a few 

contain sufficient quantities of detrital ferromagnesian minerals and rock fragments to be classed as 

graywackes. Many beds are weakly cemented, but 

some are strongly cemented with calcite. Intervals 

between sandstone beds, though usually concealed, 

consist of beds of clay and silt and their more indurated counterparts, shale and siltstone. Contacts 

between argillaceous units and sandstone beds commonly show channel or cut-and-fill structures. Several unconsolidated clay beds evidently represent 

fossil soil zones. Although this part of the Mojado 

is not conspicuously fossiliferous, fossil wood and 

pelecypod remains are found in a few beds. Except 

for rare oyster-bearing beds, the lower part of the 

type Moj ado Formation appears to be of continental 

origin. 

Lithologically, the upper part of the formation is 

much like the lower in that brown-weathered sandstone and interbedded shale and clay beds predominate. However, it differs from the lower part by 

having beds of calcareous sandstone, brownweathered quartzose and silty limestone, and brownweathered coquina limestone, all of which are rich 

in marine fossils. The thin bed bearing Tempskya 

zelleri is between two such marine beds. These fossiliferous beds include the diagnostic biota described 

later. The proportion of calcareous beds increases 

upwards to the uppermost exposure of the formation, beyond which the beds are concealed by alluvium. Most beds of the upper part were probably 

deposited under continental conditions, but the fossiliferous calCareous beds represent brief periods 

of marine flooding. 

From the type section, the Moj ado Formation is 

sporadically exposed for about 7 miles to the eastsoutheast. It is shown on the Dog Mountains quadrangle map (Zeller, 1958a) as Cretaceous sandstone 

( Ks), although the upper part of the formation 

containing the characteristic biota is not exposed 

beyond the type section. 

The lithology of the Mojado Formation exposed 

along the eastern foothills of the Animas Mountains 

about 16 miles northwest of the type section is similar to that of the formation at its type section. The 

actual thickness of the Mojado cannot be determined 

here because alluvium covers the middle part of the 

formation and conceals a known fault. However, a 

carefully estimated thickness making allowance for 

the fault suggests that in the Animas Mountains the 

Moj ado is as thick as it is at the type section. Here 

the layers that contain the same biota found at the 

type section are overlain by about 1,000 feet of 

interbedded sandstones and shales of the Mojado 

Formation. 

In Sierra Rica the Mojado Formation had originally the s·ame lithology as at the type section. However the introduction of silica, probably from nearby 

post-Early Cretaceous monzonite intrusions, caused 

alteration of the sandstone to hard quartzite and the 

shale to resistant hornfels. This section has not been 

measured or studied in detail. However, 4,000 to 

5,000 feet above the base of the formation, calcareous beds are found which contain a marine fauna 

including many of the forms found in the late 

Albian biota of the type Mojado, including the diagnostic foraminifer Cribratina texana (Conrad) 

Sample. This fauna has not been studied by specialists. 

The brief periods of marine flooding, which occurred during the time of deposition of the upper 

part of the Moj ado in the Big Hatchet area and during which the biota was deposited, also occurred in 

the areas of the Animas Mountains and Sierra Rica. 

LATE ALBIAN BIOTA IN THE MOJADO FORMATION 

Marine invertebrate fossils are closely associated 

with specimens of Tempskya in the type section of 

the Moj ado Formation and on the east side of the 

Animas Mountains (fig. 5). Collections of the invertebrates were examined by several paleontologists; summaries of their findings are included in 

the following discussion, and the relative positions 

of the collections are shown on the stratigraphic 

sections (fig. 6). 
TEMPSKY A-BEARING ROCKS OF SOUTHERN HIDALGO COUNTY 

STANDARD CLASSIFICATION 

Series European Texas Gulf 

stages Coastal Plain 

Upper Cenomanian Cretaceous 

r-? ?-

a. 

::J 

0 

(5 

~ ..c 

(/') 

ro 

~ 

en 

::J 

0 

Cl) 

(.) 

~ Albian ') Cl) 

u 

Q; 

:f; 

0 

....I 

a. 

::J 

0 

!o... 

<.!:1 

tlD 

!o... 

::J 

.0 

(/') 

..::s:: 

u 

-~ 

"0 

Q) 

!o... 

I.J.. 

Area south of 

Big Hatchet 

Mountains 

(composite section) 

COWBOY SPRING 

Covered 

.:-r,:~: ... ~.· 

·.· ... · .. ··:·.·:·:·. 

;:.· . .-::::;:·:.·:.-~·.: 

:::::::::::::: 

::.·::::::::·::.a. 

A./'A../'v 

2.400 feet of 

alternating beds 

of shale and 

sandstone 

AAAAA 

~· :::: :·.·::. ;: ::::: 

:·:.:. :::. ~. ·. :·. ·.~: 

:-.:;·::: ...... ··.· 

.·.·::_: .. ;=.·.-.::-'::··:·.· 

East of Animas 

Mountains 

(composite section) 

Not measured 

Sierra Rica 

FORMATION 

O=>ART) 

271 (USGS Mesozoic 

loc. D2096) 

M 0 J A DO 

Not measured 

=:::~-:~.:.::-.·.:;:, 

-----

················ 

-----

················-

FORMATION 

Not measured 

--~ 

r-----

r-----

f-----

::.:.::.:..-:.:.:·:::::::· f------

EXPLANATION 

Conglomerate 

~ 

~ 

D . 

. 

Sandstone 

Cross-laminated sandstone 

Calcareous 

~ 

~ 

sandstone 

Shale and claystone 

~ 

~ 

Siltstone 

Li'mestone 

ECEa tt=d 

Sandy limestone 

Silty 

~ 

~ 

limestone 

Igneous dike 

D 

Covered 

5K 272 

Fossil collection 

number 

METRES 

FEET 200 

600 

500 

400 

100 

300 

200 

100 

0 0 

c:::::~~:.~~·.::~~:·-~~~~~~~-~~~-~~,·-------c~~~-~~~~··· ___ _ 

~ U BAR FORMATION ~ 

(PART) 

FIGURE 6.-Stratigraphic sections of the Mojado and adjacent formations in the southern part of Hidalgo County, N. Mex. 

19 
20 NORTH AMERICAN SPECIES OF TEMPSKY A 

BIOTA IN THE TYPE MOJADO FORMATION 

IN MOJADO PASS 

The marine fossils collected from beds near those 

bearing Tempskya in the upper part of the type 

Mojado Formation came from the following localities :3 

Locality Descriptions 

5h Approximately 140 ft stratigraphically below the bed 

containing Tempskya zelleri. 

5i About 30 ft below the T. zelleri-bearing bed. 

5j In a bed about 5 ft below the bed containing T. zelleri. 

5k About 30 ft above the T. zelleri-bearing bed. 

5m Approximately 120 ft above the T. zelle1·i-bearing bed. 

At locality 5h (USGS loc. 26215), a collection was 

m,ade by John B. Reeside, Jr., Charles B. Read, and 

the writer. It was studied by Reeside (written 

commun., 1956) who concluded that it "would*** 

be of Washita age." He identified the following forms 

in the collection : 

Pelecypods: 

Area? sp. 

Ostrea perversa Cragin 

Plicatula? sp. 

Brachydontes? sp. 

Protocardia texana (Conrad) 

"Tellina" sp. 

Gastropod: 

Cassiope? sp. 

Several collections of gastropods were studied by 

Norman F. Sohl of the U.S. Geological Survey, who 

identified the following forms in the collections 

(written commun., 1955) : 

Locality 5i 

Nerita sp. 

Turritella ser·iatirngranulata Roemer 

Nerinea cf. N. geminata Stanton 

Py1·azus (Echinobathyra) cf. P. pecoense (Stanton) 

Cassiope sp. 

Mixed collection from localities 5i, 5j, 5k, 5m 

Turritella sr,riatimgranulata Roemer 

Pyrazus (Echinobathyra) cf. P. pecoense (Stanton) 

Sohl made the following comments concerning the 

fossils and the age significance: 

Turritella seriatimgranulata Roemer ranges through both 

the Fredericksburg and lower Washita. The specimens here 

placed in this species bear a closer resemblance to those assigned by· Stanton to the variety gainsvillensis of the lower 

Washita than to the holotype from the Walnut clay. The 

specimens of N erinea do not preserve the external ornamentation in sufficient detail for confident identification but in 

shape, whorl profile and sutural characteristics appear close 

to the type of N. geminata found in the Edwards limestone. 

Pyrazus (Echinobathyra) pecoense (Stanton) also occurs in 

the Edwards limestone. 

The known stratigraphic ranges of the individual species 

substantiates a Fredericksburg age assignment and further 

:: Originally the fossil collections made from particular beds were assigned specific collection numbers by Zeller. The additional collections made later by Reeside, Read, and Zeller from the same beds were as- signed the same collection numbers used by Zeller. For purposes of this report, the collection numbers will be referred to as locality numbers. 

suggests that the sandstone may be of late Fredericksburg 

(Middle Albian) age correlative with the Edwards formation 

of Texas. 

A collection of mollusks from locality 5k was 

studied by Norman F. Sohl, who identified the following forms (written commun., 1956) : 

Pelecypods : 

Breviarca sp. 

Ostrea sp. 

Pelecypods indet. 

Gastropods: 

Nerita (Theilostyla?) sp. 

Turritella seriatirngranulata Roemer 

Pyrazus (Echinobathyra) n. sp. 

Cassiope cf. C. hyatti Stanton 

Pseudonerinea sp.? 

N erinea cf. N. geminata Stanton 

Aptyxella (N erinoides) n. sp. 

Acteonella? sp. 

Sohl commented as follows concerning the collection and its age significance: 

Many of the mollusks are new forms and others specifically 

indeterminate. In addition a restricted age identification on the 

basis of the mollusks is difficult due to the lack of published 

information as to the total range of the few species previously 

described. Taken collectively the identifiable material ranges 

in age from late Fredericksburg to early late Washita. 

Breviarca has never been identified in the Lower Cretaceous 

but is known from the Woodbine of Texas, and its presence in 

the Washita would not necessarily be inconsistent. Among the 

gastropods, as noted in the report of November 23, 1955, Tur1'itella seriatimgmnulata Roemer has a wide range but the 

specimens in these collections appear to be closest to Stanton's 

variety gainsvillensis from the lower Washita. Pyrazus (Echinobathyra) n. sp. is close to Cerithium pecoense Stanton from 

the Fredericksburg of the Quitman Mountains area but differs 

in having a slimmer outline and additional sculpture elements. 

Cassiope cf. C. h.yatti Stanton compares rather well with the 

paratype from the Purgatoire Formation (Washita) of Mesa 

Tucumcari, N. Mex .. Nerinea cf. N. geminata Stanton externally is similar to Stanton's variety glabra of the Edwards 

but internally is closer to N. shurnlensis Stanton from the 

upper part of the Devils River Limestone (Georgetown). The 

remainder of the identifiable material has little in common with 

previously described species. 

The two most abundant species in the fauna are Turritella 

seriatirngranulata and Purazus (Echinobathyra) sp. The latter 

is typically a littoral to estuarine, brackish-water form. A 

shallow water nearshore environment of deposition is in keeping with the remainder of the assemblage as well as the 

physical wear and breakage exhibited by much of the material 

and detrital nature of the sediment. 

An ammonite in a c.:ollection from locality 5k was 

recognized as belonging to the genus Engonoceras 

by Alexander Stoyanow. Specimens of the ammonite 

were examined by Reeside, who reported as follows 

on the fossil (written commun., 1956) : 

The ammonite seems to me to be Engonocems sel'pentinum 

(Cragin), which has been reported from the Pawpaw and 

seems to be only of late Washita age. The material is good 

and the identification should be reliable. 
TEMPSKY A-BEARING ROCKS OF SOUTHERN HIDALGO COUNTY 21 

A collection of fossils was made by Reeside, Read, 

and the writer from locality 5k. In the collection 

(USGS. loc. 26111) Reeside identified the forms 

listed below (written commun., 1956) : 

Foraminifera: 

Cribratina texana (Conrad), probably including Polychasmina pawpawensis Loeblich and Tappan 

Pelecypods: 

Nucula sp. 

Yoldia sp. 

Ostrea perversa Cragin 

Lopha quadriplicata (Shumard) 

N eithea texana (Roemer) 

Camptonectes inconspicuus (Cragin) 

Plicatula sp. 

Lima? sp. 

Anomia? sp. 

Cardium aff. C. kansasense Meek 

Protocardia texana (Conrad) 

Cyprimeria gigantea Cragin 

"Tellina" sp. 

Cymbophora? sp. 

Corbula sp. 

Scaphopods: 

Cadulus? sp. 

Dentalium sp. 

Gastropods : 

"Lunatia," several species 

Tw·ritella seratimgranulata Roemer 

Anchura aff. A. mudgeana White 

Cinulia? sp. 

Cephalopod (ammonite): 

Engonoceras serpentinum (Cragin) 

Worm: 

Serpula sp. 

Reeside commented on these fossils as follows: 

The collection of invertebrates (26111) 30 feet above the 

horizon of fossil plant remains confirms the indication of the 

ammonite previously examined that the level is about the age 

of the late Washita in terms of the Texas sequence, and late 

Albian in terms of the European stage sequence. Some of the 

fossils have sufficiently marked characters to permit fairly 

assured determination. Others suggest generic assignment that 

seems well assured, but do not warrant the effort to find a 

rational specific name. Others permit only a guess at a generic 

assignment or are completely indeterminable. The fauna is 

certainly an extensive one and though the matrix is extremely 

hard and tough would be worth further study. 

The most abundant forms in the collection are the foraminifera, the Camptonectes, and the Cyprimeria. In previous reports N. F. Sohl has listed forms from the horizon of silicified 

gastropods that lies below the plant remains. These are in 

reasonable agreement with an assignment to a late Albian age. 

Arenaceous Foraminifera are found throughout 

the entire faunal zone from which the above-described faunas were collected, including localities 5h 

through 5m. Examples of these fo:rms were studied 

by Ruth Todd, who reported on them as follows 

(written commun., 1955): 

These arenaceous Foraminifera range from cylindrical individuals to flattened ones (as much as 3 to 1). In the cylindrica! 

individuals the aperture consists of a group of openings between the sand grains at the top of the final chamber. In the 

flattened individuals the aperture consists of a string of slits 

at the top of the final chamber. Two generic names have been 

applied to forms like these: Cribratina Sample, 1932 4 for the 

cylindrical ones and Polychasmina Loeblich and Tappan 19·46 

for the flattened ones. So far as I can determine, cylindrical 

and flattened specimens have not previously been found occurring together. Their presence together here, with numerous examples of gradational forms from cylindrical to flattened, 

throws doubt upon the validity of the generic separations as 

resting upon :flattening of the test and consequent rearrangement of apertural pores. 

Comparisons have been made with types of Cribratina texana 

(Conrad) and Polychasmina pawpawensis Loeblich and Tappan and all these specimens can be included in these two species. 

It seems likely, however, that the earlier name, C. texana, 

should be used for all the specimens. 

Without settling the question of whether one or two genera 

are represented here, the following notes include the age indications given by both Cribratina texana and the genus Polychasmina (which is represented by only one species). 

Cribratina texana (Conrad): 

In Grayson, Weno, and Maness? of Washita· age 

(Frizzell, 1954, p. 58) 

In Washita group (except Fort Worth); Fredericksburg and Trinity records doubtful (Lozo, 1944, 

p. 547-548) 

In strata of upper Albian age in Colombia <Petters., 

1954, p. 134) 

Polychasmina pawpawensis Loeblich and Tappan: 

In Pawpaw and Weno of Washita group (Loeblich 

and Tappan, 1946, p. 242-243) 

The above records of occurrences elsewhere seem to indicate 

Washita equivalent for the age of the strata containing these 

large arenaceous Foraminifera. 

Because of the widespread occurrence of Cribratina texana in other exposures of the Mojado in 

the region, the writer has relied heavily upon this 

form for dating rocks in which it is found. To confirm further the known range of this form, he wrote 

to ,Esther R. Applin, who replied as follows (written 

commun., 1959): 

regarding the vertical range of Cribratina texana (Conrad), 

I have seen specimens of Cribratina texana only in outcrop 

samples of sediments of Washita age in Texas and, so far as 

I know, this fossil is restricted in its range to the upper half 

of the Wash ita group. In Texas it has been reported from the 

Grayson marl and the Weno clay and some questionable specimens were also recorded from the Maness shale. 

BIOTA IN THE MOJADO FORMATION OF THE 

ANIMAS MOUNTAINS 

In the upper part of the Mojado Formation on the 

east side of the Animas Mountains (near center of 

4 In the original "Report on Referred Fossils" prepared by Ruth Todd, the name Haplostiche was applied to the cylindrical Foraminifera men- tioned here. Since then, however, paleontologists have come to restrict the name Haplostiche to Foraminifera that have a single terminal aperture 

(Loeblich and Tappan, 1964, p. C220). Those having multiple apertures, like the Foraminifera discussed here .iare then referred to Cribratina 

Sample, 1932. Therefore, in order to bring the present report into line with current practice, the authors have changed the name of the fossil formerly called Haplostiche to Cribratina wherever it appears in the re- port. The authors of this report are grateful to W. A. Cobban and Harlan Bergquist for pointing out this change in nomenclature. 
22 NORTH AMERICAN SPECIES OF TEMPSKY A 

sec. 13, T. 31 S., R. 18 W.), the writer made two 

collections of marine invertebrate fossils from beds 

stratigraphically beneath those containing T. 

reesidei and one collection from the beds above. 

These collections were studied by W. A. Cobban 

(written commun., 1959). They contain several 

forms that were also recognized in the type Mojado, 

as noted above; these are indicated by an asterisk 

( *) in the following lists. 

The collection of fossils from USGS Mesozoic 

locality D2096, about 65 feet below the T. reesideibearing bed, contains the following forms: 

Foraminifera: 

*Cribratina texana (Conrad) 

Pelecypods: 

*Lopha cf. L. quadriplicata (Shumard) 

Trigonia cf. T. emoryi Conrad 

* Protocardia texana (Conrad) 

Corbula basiniformis Adkins 

Scaphopods: 

*Cadulus sp. 

* Dentalium sp. 

Gastropod: 

Drepanochilus kiowana (Cragin) 

Cephalopod (ammonite): 

* Engonoceras serpentinum (Cragin) 

Cobban concluded that "The pelecypods, gastropod, and ammonite suggest a late Comanche 

(Washita) age (late Albian)" for this collection. 

In a collection from USGS. Mesozoic locality 

D2097, about 40 feet below the bed containing T. 

reesidei, the following forms were identified : 

Pelecypods : 

*Ostrea sp. 

Exogyra sp. 

Trigonia emoryi Conrad 

*Protocardia texana (Conrad) 

Gastropods: 

Turritella kansasens,is Meek 

Actaeonella sp. 

Cephalopod (ammonite): 

*Engonoceras serpentinum (Cragin) 

According to Cobban, "This fauna suggests a 

Washita age." 

The following fossils were collected from USGS. 

Mesozoic locality D2098, about 20 feet above the bed 

containing T. rees1:dei : 

Foraminifera: 

C1'ibratina texana (Conrad) 

Pelecypod: 

* Protocardia texana (Conrad) 

Gastropod: 

Drepanochilus kiowana (Cragin) 

Cobban considered that this collection is "a 

Washita fauna." 

CONCLUSIONS REGARDING THE AGE OF' THE BIOTA 

The age determinations of the different elements 

of the marine fauna associated with Tempskya spp. 

in the Mojado Formation are in close agreement. At 

the type locality, the pelecypods and gastropods in 

localities 5h, i, and j (stratigraphically below the bed 

containing T. zelleri) range in age from late Fredericksburg to early late Wash ita; the ammonite and 

the mollusks from locality 5k (str-atigraphically 

above the beds containing T. zelleri) are of late 

Washita age; Foraminifera from localities 5h, k, 

and m are also of Washita age. On the east side of 

the Animas Mountains, two collections of Foraminifera and mollusks from the beds overlying those 

containing T. reesidei are also of Washita age. Thus, 

it is evident that these faunas range in age from late 

Fredericksburg to late Washita in terms of the 

Texas Coastal Plain classification and are of late 

Albian Age according to European terminology. It 

can be further concluded that the Tempskya spp. in 

the Moj ado Formation are of the same age. 

Cowboy Spring For-mation.-The Cowboy Spring 

Formation is named for Cowboy Spring in the 

Animas Mountains. The type locality is in sec. 13 

and 24, T. 31 S., R. 18 W., and in sees. 18 and 19, 

T. 31 S., R. 17 W. The basal beds intertongue with 

the upper beds of the Mojado Formation. The formation consists of limestone cobble-and-boulder conglomerate and a few thin beds of shale. A limestone 

conglomerate of Tertiary age rests with angular unconformity upon the Cowboy Spring Formation; 

rock types of the two formations are so similar that 

they are difficult to distinguish. Although the total 

thickness of the Cowboy Spring Formation has not 

been measured at the type locality, it is at least 500 

feet. Because the cobbles and boulders were apparrently derived from a nearby source, the formation 

is probably restricted to the area near its present 

exposures. No fossils have been found in the Cowboy 

Spring Formation, but it is believed to be of very 

lat.e Albian Age because of its intertonguing relationships with the underlying Mojado and because 

its lithology suggests rapid deposition. However, it 

could possibly be of very early Cenomanian (early 

Late Cretaceous) Age. 

SYSTEM A TIC DESCRIPTIONS 

Division PTEROPHYT A 

Family TEMP SKY ACEAE 

Genus TEMPSKYA Corda, 1845 

The following are the more important references 

to the genus. 

1845. Tempskya Corda, p. 81. 

1911. Tempskya Corda: Kidston and Gwynne-Vaughn, p. 1-20. 
SYSTEMATIC DESCRIPTIONS 23 

1924. Tempskya Corda: Seward, p. 485-507. 

1937. Tempskya Corda: Read and Brown, p. 108-112. 

1947. Tempskya Corda: Andrews and Kern, p. 119-186. 

1970. Tempskya Corda: Andrews, p. 485-487. 

The first clearcut generic diagnosis of the genus 

Tempskya was prepared by Kidston and GwynneVaughan (1911, p. 13) and is as follows: 

Stems of small diameter, erect, dichotomous, and embedded 

in a felted mass of their own adventitious roots. Dorsiventral, 

with the leaves in two rows on one side of the stem and roots 

alone on the opposite side. Vascular system of stem a solenostele. Leaf trace departs as a single strand. Roots diarch. 

Seward (1924), Read and Brown (1937), and 

Andrews and Kern (1947) have more recently discussed the generic characteristics of Tempskya at 

some length. In consequence, it is unnecessary to 

elaborate in this report. However, a concise account 

appears to be appropriate in view of the fact that 

much of the older literature is not readily available 

to many workers. 

Stem.-The stems of Tempskya ·are dorsiventrnl 

and are characterized by solenosteles. The protoxylem is exarch or slightly immersed. Both the pith 

and the cortex are characterized by variable amounts 

of parenchyma and sclerenchyma, the di,stribution 

patterns of which appear to have some value "in 

specific taxonomy. The stem system is freely dichotomous and is sheathed in a thick and very dense felt 

of adventitious roots. 

A well-preserved to poorly preserved endodermis 

constitutes the inner and outer limits of the stele. A 

very thin layer of pericycle and phloem occurs both 

on the exterior and interior of the stele and together 

with the endodermis wraps around the terminations 

of the steles when they are gapped during the emission of leaf traces. Because of the nature of the. 

preservation of the material, it is rarely, if ever, 

possible definitely to separate the pericycle from the 

phloem. The xylem cylinder is exarch. In most 

species the protoxylem appears to form a continuous 

or nearly continuous band on the exterior, but in 

some it is discontinuous and occurs as discrete 

strands. Variable quantities of xylem parenchyma 

occur interspersed with the tracheids in the metaxylem. 

Leaf trace and phyllodium.-Leaf traces are given 

off from the stele in the manner characteristic of 

solenostelic types of ferns and are in two ranks. The 

stele below the point of emission thins primarily by 

reduction of the width of the xylem ·stvand and 

finally gaps, permitting the departure of a thin, 

broad, and inverted U-shaped strand which is completely encircled by a thin layer of phloem and pericycle bounded by the endodermis. The gap is quickly 

closed above the point of departure. As the strand 

passes through the cortex, cortical tissues are disposed around the foliar stele in the ·same manner 

that they are developed in the stem, except that the 

thicknesses of the zones diminish. As they emerge 

into the phyllopodi.a, the terminations of the inverted U become enlarged and recurved. The xylem, 

except at the terminations, is rarely more than two 

cells thick, and in some instances, as shown in plate 

12, figure 1, it is only one cell thick. Midway on the 

dor·sal surface of the stele as the strand continues 

outward, a depression or furrow forms. Both the 

leaf traces and the phyllopodia are rather small, as 

might be expected in view of the size of the parent 

stems. In consequence, the fronds of Tempskya were 

undoubtedly rather ~small. 

Root.-The adventitious roots that sheath the 

stems and phyllopodia of Tempskya are diarch and 

characterized by relatively large steles. The cortex 

is characterized by a narrow inner layer of parenchyma beyond which is a thick zone of sclerenchym,a. In well-preserved specimens a layer of 

large-celled parenchy.ma lies on the exterior of the 

sclerenchyma; this has a tendency to become lacunar 

as a result of the breaking down of some of the cell 

walls. Sheathing this layer are smaller and thicker 

walled cells of the epidermal zone. In some specimens, well-preserved root hairs are present, which, 

as in the case of modern plants, are outgrowths from 

the epidermis. 

False trunk.-The most striking characteristic of 

the genus Tempskya, and the feature that serves to 

set it apart from most of the other ferns, is the false 

trunk or "stem." When viewed with the eye directly 

or under a hand lens, specimens of Tempskya are 

seen to be an aggregate of stems, phyllopodia, and 

adventitious roots. The roots parallel to subparallel 

the course of the stems and are so numerous that 

they form a dense felt which apparently in life 

served to bind the branching stem system into a 

massive stem or trunklike body. 

According to Andrews and Kern (1947) the parts 

of the false trunks they examined may be classified 

into bases, discs, and tips. To some extent, as these 

authors point out, this differentiation is interpretative. The bases of some flare slightly at the very bottom, have a knobby lower surface, and consist entirely of roots. Disc specimens are massive columnar 

segments of false trunks with many well-preserved 

true stems as well as abundant adventitious roots. 

At least in some cases, the true stems ~are penetrated 

by the adventitious roots. The specimens interpreted 

as tips are reported to "taper rather abruptly to a 

blunt apex" (Andrews and Kern, 1947, p. 121). Such 
24 NORTH AMERICAN SPECIES OF TEMPSKY A 

specimens are interpreted as the terminal parts of 

false trunks. 

Although Andrews and Kern questioned the existence of dorsiventral false trunks, it has not been 

clearly demonstrated that radial symmetry of false 

trunks is a constant characteristic of the genus 

Tempskya. In fact one of the new fossils from New 

Mexico seems to indicate the reverse. 

One of the new discoveries that throws additional 

light on the general morphology of the false trunks 

is the paratype (USNM 167547) of T. reesidei. The 

specimen is approximately 62 em long and is tapered 

similarly to and is quite reminiscent of the holotype 

ofT. knowltoni. (See figs. 8 and 9; pl. 3, fig. 3.) The 

upper part of this specimen is radially symmetrical 

(fig. 9A) and contains some well-preserved stems. 

The tip or lower part of the specimen ~ontains remains of only three stems; these have been penetrated by many adventitious roots. (See fig. 9B.) 

The occurrence of an additional obconical false 

trunk must be taken seriously into account. It certainly demonstrates that Tempskya showed this 

growth form, at least occasionally, substantiating 

the idea that the holotype of T. knowltoni, which 

is dorsiventral, represents an entire false trunk and 

not a segment as Andrews and Kern (1947) thought. 

This in turn seems to indicate that radially symmetrical false trunks were not a constant characteristic of the genus. 

Growth habit.-The growth habit of Tempskya 

has been a matter of speculation for many years. As 

noted, Kidston and Gwynne-Vaughn (1911) discussed the subject and prepared a reconstruction 

that Stopes published in 1915. (See fig. 1 of this 

report.) Later Seward (1924), Read and Brown 

(1937), and Read (1939) considered the problem, 

but it was not until1947 that a new restoration was 

attempted. In that year, Andrews and Kern analyzed 

all the information available about the growth habit 

of Tempskya and published the somewhat different 

reconstruction reproduced here as figure 2. 

Andrews and Kern (1947) showed that in material they identified as T. 1oesselii, the courses of 

some of the branches of the stem system were somewhat oblique, as though passing to the margins of 

the false trunks below the apices. They interpreted 

this emergence at lower levels as indicating that the 

false trunks were invested by fronds for some distance below the apical area of the composite organ. 

As a result, the reconstruction of a radially symmetrical Te·mpskya published by Andrews and Kern 

shows the upper two-thirds of the false trunk bearing several irregular clusters of fronds. (See fig. 2.) 

Thus, it contrasts somewhat with the restoration 

published by Stopes. (See fig. 1.) 

Although the authors of this report do not entirely 

agree with the interpretation that the false trunks 

bore fronds well below the apices, the situation noted 

by Andrews and Kern has also been observed in 

T. reesidei. There appears to be little if any evidence 

of such marked divergences in the other well-preserved species of the genus, and in T. zelleri the 

stems appear to be confined to the central area of 

the false trunk. In view of the fact that fern fronds 

are rather ephemeral organs, it would follow, should 

Andrews and Kern's interpretation be correct, that 

the branched stem system must have been more 

rapidly growing than is common in ferns. It seems 

more likely that the leaves were confined to an apical 

crown at any given time, somewhat as suggested by 

Stopes, rather than loosely distributed along the 

margins of more than half of the false trunks. 

Andrews and Kern (1947, p. 133) pointed out that 

although paleobotanists like to compare fossil plants 

with modern ones, we may, in the case of Tempskya, 

be "dealing with a different mode of increase in the 

diameter of the trunk, as well as a highly unique 

physiological setup with regard to photosynthesis 

and transportation of fluids." Ordinarily, the stems 

of tree ferns, palms, and cycads, all of which have 

certain physiological and architectural similarities 

to the false trunks of the tempskyas, are characterized by crowns or apical growths of large and usually 

compound leaves or fronds. In Tempskya, however, 

it is rather unlikely that the fronds ever reached a 

length much g·reater than 30 em, because the diameters of the phyllopodia in Tempskya are much 

smaller than the diameters of similar organs in tree 

ferns, cycads, and palms. On the basis of this characteristic Andrews and Kern believed that the 

Tempskya false trunks must have had many more 

fronds than do modern tree ferns, cycads, and palms 

in order to have achieved the necessary balance of 

photosynthesis. 

Although we do not attempt a restoration here, 

we would like to make a few comments about the 

growth habit of Tempskya. To begin with, as it is 

generally agreed that most, and probably all, specimens of Tempskya are the remains of single plants 

rather than of a colony of ferns, then the massive 

and complexly branched stem systems must have 

originated from single stems. In addition, the individual stems are dorsiventral. In consequence, the 

young plants must have been horizontal and must 

have developed the unusual upright characteristic 

only after sufficient massivenes's through branching 
SYSTEMATIC DESCRIPTIONS 25 

had been achieved so that the composite or false 

trunk was sufficiently strong to support itself completely or partly. Both the holotype of T. knowltoni 

and the paratype (USNM 167547) of T. reesidei are 

interpreted as parts of false trunks immediately 

adjacent to the very young plant. In other words, 

they prob~bly represent an early stage in the development of the plant while the growth was still 

horizontal. The specimens referred to as bases by 

Andrews and Kern quite possibly were fairly low in 

the false trunk and formed after the plant attained 

an upright stance; they must have been above the 

broadly rounded terminations discussed above. 

T empskya reesidei Ash and Read, n. sp. 

Plates 1-4; figures 7-9 

Diagnosis.-False trunks large, 10-30 em in diameter, radially symmetrical; individual stems usually 

3-5 mm in diameter; internodes long, usually showing one or two, rarely three, leaf traces in a transverse section; cortex two layered, outer layer of 

parenchyma cells with dark contents, about 10 cells 

wide, inner layer narrow, about five cells wide, composed of small, thick-. walled sclerenchyma cells, inner 

layer containing irregular, elongate "island like" 

bodies of P'arenchyma; outer endodermis present; 

pericycle and phloem thin; xylem with little interspersed parenchyma; interior phloem and endodermis present; pith composed of an outer layer of 

sclerenchyma and a center composed of parenchyma 

and large sclerenchyma cells. Adventitious roots 

randomly oriented. 

Description.-The holotype of T. 1·eesidei n. sp. 

is a false trunk ranging in diameter in the apical 

part from about 20.5 X 11 (circumference of 52.5 

em) to 27.5 x 16.2 em (circumference of 71.3 em) 

near the base of the preserved part of the false stem. 

As indicated in figure 7, the false trunk is characterized by more than 425 stems sheathed in a loose mass 

of adventitious roots. The stems, in gene:rnl, are 

radially disposed. In the ·central area of the false 

trunk, most of the stems are vertical in their orientation. However, it is apparent that the stems in 

the peripheral zone have a pronounced tendency to 

be obliquely oriented and to trend outward to the 

margin of the false trunk (pl. 1, fig. 1). Many leaf 

traces and base·s are visible in the diagram (fig. 7), 

and many phyllopodia may be seen. In the section 

very few, if any, of the stems are penetrated by 

adventitious roots of Tempskya. Consequently, we 

suggest that the stems may have been functional at 

a distance of at least a meter below the apical area 

of the false trunk. Although in certain details the 

stems are not strictly equally dichotomous, the variations are sufficiently minor that for general purposes 

the branching can best he described as equally dichotomous. It also appears from the abundance of 

leaf traces, bases, and phyllopodi~a related to the 

various stems at any given level that the stems are 

characterized by long internodes. Equally apparent 

from the section is the fact that the departure of the 

leaves from the stem must have approached a right 

angle, in comparison with the very 'acute angles 

characteristic of most other American species of 

Tempskya. 

Figure 8 is a reconstruction of the paratype of the 

species that was found in place and removed by the 

writers. This specimen is also shown on plate 3, 

figure 3. The fossil is irregularly tapered and is 

reminiscent of the specimen of T. knowltoni described by Seward (1924). Cuts were m'ade in this 

specimen at two levels, as indicated in figure 8. The 

larger slice, approximately through the middle of 

the specimen, is shown diagrammaticrally in figure 

9A. Some stems are shown in the false trunk with a 

rather imperfect radial sym.metry. Present and of 

interest are foreign objects indicated at d. The po.sition of two of these is also shown in the profile (fig. 

8). Both the stems and the foreign vegetative bodies, 

which are fragmentary stems of a woody dicotyledonous plant, are penetrated by the adventitious 

roots of Tempskya and are sufficiently broken down 

(morphologically) so that the details of structure 

can be ascertained in only a general way. 

The section illustrated in figure 9B was cut approximately 5 em from the tip of th~ horn-shaped 

specimen; it has only three stems in it, and again 

these are penetrated by many roots. 

Plate 1, figures 1 and 2, illustrate the anatomy of 

Tempskya reesidei at rather low magnification. It is 

apparent that the stems are solenostelic and are 

dorsiventral. The leaf traces depart in two ranks 

from the stem on one side, and adventitious roots 

are derived at random on the rest of the stem surface. The leaf traces, bases, and phyllopodia are 

characterized by U-shaped steles that are rather 

broad and short in cross section. A considerable 

amount of sclerenchyma is evident in both the stem 

and phyllopodia. The stems are sheathed in a mass 

of adventitious roots, many of which are divergent 

from the courses of the stem so that they form a 

tangled mass. In addition, the stems are sheathed by 

a thick mat of dermal emergences or epidermal hairs. 

The general characteristics of transverse and 

slightly oblique sections of T. reesidei n. sp. are 

illustrated on plates 1-4. Several leaf traces and 
26 NORTH AMERICAN SPECIES OF TEMPSKY A 

5 CENTIMETRES 
SYSTEMATIC DESCRIPTIONS 27 

bases are shown in various stages of development. 

The epidermal area cannot be clearly identified, 

although its approximate position is marked by "e" 

on plate 4. When examined in detail, the mass of 

homogeneous matted tissues on the exterior is seen 

to be a dense and relatively thick zone of epidermal 

hairs. 

Beneath the dermal zone is an outer cortical zone 

of parenchyma. This reaches a maximum width of 

approximately 10 cells and in ·most stems is poorly 

preserved. The cells are large in cross section and 

appear to have been filled with protopl,asm originally, as there is carbonaceous material embedded 

in the silica that now constitutes the filling of the 

cells. The inner margin of the outer cortex abuts 

irregularly against a narrow zone of small sclerenchyma cells. This sclerenchyma zone is rarely more 

than five cells in diameter, and because of the small 

size of the cells it is only about one-third the width 

of the outer cortex. Within this zone of sclerenchyma 

is· a second layer of parenchyma poorly preserved 

but apparently similar to the outer cortex. In cross 

section this zone of parenchyma is slightly wider 

than the bounding sclerenchyma on the exterior and_ 

is seen to be discontinuous, inasmuch as the outer 

sclerenchyma zone bridges the parenchyma at several points so that the parenchyma areas lie as 

elongate "island like" bodies within sclerenchyma. 

On the interior of the parenchyma and constituting 

a zone only slightly narrower in cross section than 

the outer sclerenchyma, is a zone of inner sclerenchyma similar to the outer zone and connecting with 

it, as is apparent on plate 1, figure 2. This in turn 

is bounded by poorly preserved or ill-defined endpdermis. Judging from the thin layer of tissues between the outer face of the xylem ring and the endodermis, little, if any, pericycle is present. In fact, all 

the tissues in this zone originally may have been 

elements of the phloem and are so indicated by the 

symbol "ph" on plate 4. 

The xylem cylinder is exarch and is rarely wider 

than six cells. A s.mall amount of xylem parenchyma 

is present, out most of the cells, except for the protoxylem, are scalariform tracheids. On the exterior 

of the xylem ring is the interior phloem and a 

vaguely marked interior endodermis. The margin of 

the pith is marked by a zone of sclerenchyma which 

reaches a maximum width of about five cells and 

within which are the remnants of large sclerenchyma cells. 

Figure 7 shows that in every section of a true 

stem there is evidence of leaf emergence in one stage 

or another, and several stages are usually apparent. 

A very early stage in the origin of leaf trace is seen 

on plate 1, figure 2. The xylem strand, as well as the 

accompanying inner and outer zones of the stele, has 

thinned and bulges outward slightly. A somewhat 

more advanced stage is shown on plate 4 where the 

stele has been gapped and the inverted U-shaped 

trace emerges at a rather oblique angle. The steepness of the angle is indic·ated by the fact that the 

stelar cells in the stem are cut in cross section, 

whereas those of the trace are oblique. 

On plate 3, figure 2, more advanced stages in leaftrace emission are shown. The inverted U-shaped 

xylem strand is slightly swollen at the terminations 

and also has a tendency to bend inward in cross 

section. It is enveloped by phloem and endodermis. 

On plate 3, figure 1, the leaf base, that is, that 

zone in emission of the foliar trace just prior to 

detachment, is shown. The shape of the stele is that 

of a low inverted U, the terminations of which bend 

·slightly inward. The stele is sheathed by tissues 

similar to those that constitute the cortex of the 

parent stem, and ·also similar to those that constitute 

the pith. 

Phyllopodia are very common in T. reesidei, n .. sp., 

as figure 7 shows. These are similar to the leaf bases 

and consist of a .sheath of poorly preserved epidermis with dermal hairs, beneath which is an outer 

parenchymatous cortex and an inner mixed sclerenchymatous and parenchymatous cortex. The stelar 

tissues are arranged in an inverted U-shaped strand 

that has invaginated terminals, and the xylem is 

exarch. Most of the phyllopodia appear to pass outward from the parent stem at rather oblique angles, 

for in planes that show the stems in .transverse 

section, the phyllopodia are usually cut diagonally, 

as shown on plate 2. 

The roots are diarch and exarch and are limited 

FIGURE 7.-Cross section of the false trunk of the holotype of Tempskya reesidei n. sp. showing the distribution and radial 

orientation of the stems. Note that they are transversely sectioned near the middle of the specimen, but are cut more 

and more obliquely as the margins are approached. The figure also indicates that the internodes are long, because 

just a few (usually two) departing leaf traces are associated with each stem. In contrast, the stems of T. wesselii 

usually have only one associated leaf trace and very long internodes, and the stems of T. grandis often have three to 

five associated leaf traces and short internodes. The low frequency of fre·e petioles in the false trunk is typical of 

T. reesidei. Adventitious roots are present throughout the section b2tween the stems, but for simplification only the 

vertically oriented ones are shown in a small part of the illustration. USNM 167546g. 
28 NORTH AMERICAN SPECIES OF TEMPSKY A 

by a well-defined endodermis, beneath which are 

small areas of phloem. The cortex appears to be 

entirely sclerenchymatous, and an outer lacunar 

zone has not been observed. In contrast to the other 

species described in this report, only a few of the 

roots of T. reesidei are oriented parallel to the parent stems (pl. 3, fig. 1). Most are oriented outwardly 

in a random fashion so that a dense tangle of these 

organs apparently was present in life. 

Remarks.-The species is named for John B. 

10 em 

Reeside, Jr., who took great interest in the stratigraphic range of Tempskya for many years before 

his death in 1958. 

Material.-Holotype: USNM 167546. Paratype: 

USNM 167547. 

Distribution.-This species occurs in the Moj ado 

Formation on the east flank of the Animas Mountains, Hidalgo County, N. Mex., at USGS fossil 

plant locality 9703. 

T empskya zelleri Ash and Read, n. sp. 

Plates 5-7; figure 10 

1956. Tempskya minor Read and Brown: Zeller and Read, p. 

1804. 

Diagnosis.-False trunks small to medi urn, as 

much as 17 em in diameter, radially symmetrical ; 

individual stems usually 3-8 mm in diameter, distinctly angular in cross section ; internodes very 

long, usually showing one, rarely· two or three, leaf 

traces in a transverse section; cortex three-layered, 

outer layer narrow, composed of parenchyma, middle 

layer wide, composed of sclerenchyma, inner layer 

wide, composed of parenchyma; outer endodermis 

present; outer pericycle and phloem thin; xylem 

exarch with little interspersed parenchyma; inner 

phloem, inner pericycle, and endodermis present; 

pith consisting of thin outer layer of parenchyma 

and a central area of sclerenchyma. Free petioles 

rare. Adventitious roots usually vertically oriented. 

Description.-The largest specimen of T. zelleri 

that has been collected is about 17 em by 11 em in 

diameter; it is illustrated diagrammatically in figure 

10. Thirty-two stems are present and are oriented 

so that the false·trunk has a crude radial symmetry. 

The stems are all in a central zone in the false trunk, 

on the exterior of which is a rindlike area made up 

entirely of adventitious roots. The stems are all 

vertical or nearly vertical in their orientation in the 

false trunk, are small, and are equally dichotomous. 

The low number of leaf traces associated with each 

stem suggests relatively long internodes, longer than 

in T. reesidei Ash and Read. 

FIGURE 8.-Reconstruction of the basal part of the false trunk 

of the paratype of Tempskya reesidei n. sp. Fragments of 

the specimen that were recovered are shown unpatterned 

and the missing parts are patterned. The position of the 

cross sections in figures 9A and B are indicated by the 

straight lines at a and b, respectively. Places where stems 

of woody dicotyledonous plants adhered to the exterior of 

this false trunk of T. reesidei when it was alive are indicated by d. Solid lines show the present extent of this 

foreign vegetative material, and the dashed lines delineate 

the impressions they made on the surface of the false trunk 

by other parts of these same woody stems. USNM 167547. 
SYSTEMATIC DESCRIPTIONS 29 

( 

d 

B 

FIGURE 9.-Cross sections of the false trunk of the paratype of Tempskya reesidei shown in figure 8; USNM 

167547. A, Section cut through about the middle of the specimen (at a in fig. 8), showing the comparatively large number and orientation of the stems and the remains of three foreign vegetative bodies (d). Compare the number of 

stems in this section with the three in the section cut through the basal part of the fossil shown in figure 9B. Adventitious roots are not show.n in the figure although they are abundant in the section. B, Section cut through the 

basal part of the specimen (at b in fig. 8). Note the rarity of stems in this section. The bulk of the false trunk at this 

level is composed of adventitious roots, but simplification they are not shown. 

The most characteristic feature of all specimens 

of this species that have been examined is the angular nature of both the steles and the stems when 

viewed in cross section. It was at first thought that 

this angularity might be due to crushing of the plant 

material during the processes of sedimentary loading and postdepositional deformation of the containing rocks in the Big Hatchet Mountains. However, 

as is indicated by the diagram (fig. 10), the largest 

specimen is nearly equidimensional in cross section, 

and there is no apparent relationship between the 

small amount of flattening that may be inferred and 

the orientation of the stems. In addition, the tissues 

of the stem, as will be shown at a later point, are 

not crushed or deformed any more than in other 

species of Tempskya that do not show the angular 

characteristics that seem to mark this form. In consequence, the writers are forced to a·ssume that the 

angularity is characteristic of the species, just as it 

is a characteristic of some genera and species of 

modern ferns. 

The general characteristics of the stems are illus-
30 NORTH AMERICAN SPECIES OF TEMPSKY A 

0 2 CENTIMETRES 

FIGURE 10.-Cross section of the false trunk of the holotype of Tempskya zelleri n. sp. showing the distribution and 

crude radial orientation of the stems. In this specimen they are concentrated more or less near the middle of 

the false trunk and generally are transversely sectioned, contrasting in both of these features with T. reesidei n. 

sp. Compare the diagram with the cross sections of T. reesidei n. sp. (figs. 7 and 9A) . Another significant feature of the species that can be seen in the figure is the angularity of the stems which contrasts with the rounded 

stems of T. reesidei n. sp. and all the other known species of the genus. Adventitious roots are present throughout 

the section, but for simplification they are shown as small circles in a part of the illustration. USNM 167543. 

trated on plates 5 and 6. They are dorsiventral and 

give off leaf traces in two ranks. Only rarely is more 

than one leaf trace seen in a single transverse section 

associated with a single stem. (See plates 5 and 6.) 

In consequence, it may be assumed that the internodes are somewhat longer than in T. reesidei. From 

the point of their inception the leaf traces are seen 

to be oblique in comparison with the orientation of 

the stem, so it may be assumed that they pass out 

from the parent stem at rather low angle to the stem. 

In the stems examined, the epidermis is rarely 

preserved. The outer cortex appears to be a zone 

about one-fifth the width of the entire cortex. It is 

poorly preserved and parenchymatous. The middle 

cortex consists of sclerenchyma, which judging from 

the sizes of the lumens, may be stone cells, and is at 

least three times the thickness of the outer cortex. 

It is usually dark brown, and the lumens appear to 
COMPARISONS OF THE SPECIES 31 

be nearly closed. Bordering the middle cortex is the 

inner cortex which is at least twice the width of the 

outer cortex and on the average slightly narrower 

than the middle cortex. The inner cortex is thinner 

walled than the middle cortex and appears to be 

parenchyma. The endodermis is fairly well defined 

in this species, and internal to it is a very thin zone 

of pericycle and phloem. These tissues are all illustrated on plate 7. The xylem is e~arch and, like 

Tempskya minor, the protoxylem appears to be a 

series of clusters rather than a continuous ring. One 

especially prominent cluster of protoxylem is seen 

on plate 7. It will be noted on this pl,ate that adjacent 

to the prominent protoxylem, large metaxylem cells 

extend to the interface of the xylem and phloem. The 

xylem is from four to as many as eight cells wide. 

It is characterized by an abundance of sm,all-celled 

xylem and parenchyma interspersed with the scalariform tracheids. A narrow zone of inner phloem and 

pericycle within the xylem ring is bounded by the 

inner endodermis. The pith is characterized by a 

thin outer ring of parenchyma and a central area 

of sclerenchyma. 

Leaf traces cut at low levels are shown on plate 6, 

figure 3 (upper left), and others cut at higher levels 

are on plate 6, figure 2. The leaf traces depart at a 

very low angle from the xylem ring and from the 

stem in general. Thus, on plate 6, figure 3, the xylem 

ring of the stem is in cross section except for the 

part that is bulging into a leaf trace. In this protrubence the tracheids are slightly oblique. At a still 

higher level (pl. 6, fig. 3; pl. 7), the same obliqueness 

may be noted. The leaf traces are inverted U shaped 

with inv.aginated or recurved ends. The xylem is two 

or three cells wide except at the terminations, where 

knoblike bulges cause it to be as much as six cells 

wide. The xylem is completely surrounded by phloem, 

a thin zone of pericycle, and the endodermis. The 

inner cortex within the inverted U of the stele is a 

very thin zone of parenchyma, and the middle cortex 

is a thick zone of sclerenchyma. The cortex on the 

exterior of the inverted U of the stele consists of a 

much thicker inner parenchymatous zone and a 

somewhat thinner sclerenchymatous middle cortex. 

Phyllopodia are rarely seen in specimens attributed to this S·pecies. 

The roots are diarch and exarch, have only a few 

tr~acheids, are sheathed by a thin zone of phloem and 

pericycle, and the stele is bounded by a very well 

defined endodermis (pl. 7). The cortex appears to 

be almost entirely sclerenchymatous. No evidence of 

an outer lacunar cortex was observed in the roots of 

this species. The long axes of the adventitious roots 

ofT. zelleri appear to be oriented parallel to the long 

axes of the stem in most cases. Exceptions, of course, 

occur at the point of departure of the adventitious 

roots from the stem where the long axes tare at 

nearly right angles. The orderly orientation of the 

adventitious roots in this species contrasts strongly 

with the random orientation of the roots, with the 

resultant tangle that appears to be so characteristic 

of T. reesidei. 

Remarks.-The species is named for Robert A. 

Zeller, Jr., who collected many of the specimens on 

which this species and T. reesidei n. sp. ~are based 

and who was an authority on the geology of southwestern New Mexico before his untimely death in 

1970. 

Material.-Holotype: USNM 167543. Paratypes: 

USNM 167541, 167542, 167544. 

Distribution.-T. zelleri occurs in the Mojado 

Formation south of the Big Hatchet Mountains, 

Hidalgo County, N. Mex., at USGS fossil plant locality 9702. 

COMPARISONS OF THE SPECIES OF TEMPSKY A 

At present, nine species of Tempskya have been 

described from North America. These are Tempskya 

grandis Read and Brown, T. knowltoni Seward, T. 

mino1· Read and Brown, T. reesidei Ash and Read, 

T. superba Arnold, T. wesselii Arnold, T. whitei 

Berry, T. wyomingensis Arnold, and T. zelleri Ash 

and Read. In addition, several species ~are known in 

Europe, and two of these, T. rossica Kidston and 

Gwynne-Vaughan and the new Tempskya from England are based on very well preserved material. The 

following discussion is restricted to the well-preserved species in North America and to T. rossica. 

The several European species that are based on 

poorly preserved material, •and T. whitei Berry, 

which is also known only from poor specimens, are 

mentioned only incidentally. 

False trunks.-The several species of the genus 

Tempskya are tentatively classified into two groups 

according to the symmetry of the false trunks, one 

being characterized by dorsiventral false trunks and 

the other by radially symmetrical false trunks. T. 

knowltoni and T. minor continue to be the only 

known species that have dorsiventral f.alse trunks. 

The radially symmetrical group now includes T. 

grandis, T. rossica, T. superba, T. wesselii, T. wyomingensis, and the two new species described here, 

T. 1·eesidei and T. zelleri. 

Stems.-It was suggested by Read and Brown 
32 NORTH AMERICAN SPECIES OF TEMPSKY A 

(1937) and again by Arnold (1945) that variations 

in dispositions of tissues in the cortex of the stems 

must have systematic value. The writers agree with 

the earlier findings and place emphasis on the cortical characteristics. 

Two groups of Tempskya may be recognized on 

the basis of the disposition of tissues in the cortex, 

the first characterized by a simple cortex consisting 

of inner parenchymatous, middle sclerenchy·matous, 

and outer parenchymatous zones. the outer parenchymatous zone, in some cases, being reduced to only 

a few cells in thickness. The second group is characterized by an inner mixed zone of parenchyma and 

sclerenchym:a, a middle sclerenchymatous, and an 

outer parenchym1atous zone. Parenthetically, the 

usage of the terms inner, middle, and outer zones of 

the cortex does not mean that these are homologous 

tissues (Arnold, 1945). As here used, the terms 

si~mply refer to position with respect to the epidermis and to the stele. 

The group characterized by the simple threelayered type of cortex includes T. zelleri, T. knowltoni, T. minor, and T. rossica. Idealized diagvams of 

the stems of these species :are shown in figure 11, and 

anatomical details of T. zelleri are illustrated on 

plates 5-7. Details of T. knowltoni are shown on 

plate 8 and those of T. minor on plate 9. In these 

four species, the cortex is characterized by an inner 

zone of parenchyma, a middle zone of sclerenchyma, 

and .an outer zone of parenchyma. The rel<ative 

widths of these zones probably are fairly constant, 

but the exact widths are probably functions of relative sizes of the stems. 

In the second group, characterized by mixed tissues in the inner cortex, several architectural patterns as viewed in cross sections appear to be of 

specific value. Diagrams of the stems of T. reesidei, 

T. grandis, T. wyomingensis, T. wesselii, and T. 

superba are also shown in figure 11. Anatomical details of T. 'teesidei .are illustrated on plates 1-4, 

whereas those of T. grandis are shown on plate 10, 

those of T. wyomingensis, on plate 11, those of T. 

wesselli; on plate 12, .and those of T. superba, on 

plate 13. 

In Tetnpskya grandis and T. superba an irregular 

and discontinuous band of sclerenchyma divides the 

inner and dominantly parenchymatous cortex into 

three bands, as is indicated in the diagra~ms. In T. 

reesidei, T. wesselii, and T. wyomingensis the inner 

cortex is chavacterized by inner and outer zones of 

sclerenchyma separated by a continuous or discontinuous band of parenchyma. According to Arnold 

(1945), in T. wesselii and T. wyomingensis these 

bands of sclerenchyma are actually stone cells. In 

T. reesidei the middle belt of parenchym~a is discontinuous by reason of radial bands of sclerenchyma 

that connect the inner and outer continuous zones of 

sclerenchyma. In T. wesselii and T. wyomingensis, 

the middle zone of parenchyma is continuous, according to Arnold (1945). 

Epidermal emergences that .appear to be simple 

hairs are characteristic of at least two species, 

Tempskya zelleri and T. minor. Because the epidermis is rarely preserved in most stems, such structures may have occurred in other species. 

Except for differences in diameters, the steles of 

all species are fairly similar in their characteristics, 

although there ~are some slight differences. For instance, the protoxylem in most species appears to 

form a continuous or nearly continuous band on the 

exterior of the xylem cylinder, whereas in T. zelleri 

and T. minor it is discontinuous and occurs as discrete strands. 

Earlier it was thought by one of the writers that 

variations in amounts of xylem parenchym~a might 

be of value in separating some of the species (Read 

and Brown, 1937). Arnold (1945) discussed this 

problem and was inclined to question the value of 

this criterion. After reviewing the matter on the 

basis of new material in hand as well as the material 

earlier descri'bed, the writers are now inclined to 

agree with Arnold. The xylem is rarely more than 

9-10 cells wide ~and is usually less. 

The morphological details of the leaf traces and 

phyllopodia are in general similar, except for the 

envelopment qf the epidermis. At present, except for 

the variations in cortex, the writers are una;ble to 

recognize any differences in these organs in the 

various known species. 

One observation of possible value has been m~ade, 

however, regarding the presence or absence of preserved phyllopodia. In most species these organs are 

rarely noted, and in some, ~as T. knowltoni, they have 

not been reported, whereas, in T. reesidei they are 

quite abundant. 

The pith in all known species of Tempskya consists of two zones. The outer zone is parenchym,atous 

or a mixture of parenchyma and sclerenchyma. In 

general, it is similar to, but thinner than, the inner 

cortex of the stem. The inner or central zone of the 

pith in all species is sclerenchyma and similar to 

the sclerenchyma of the middle cortex, although 

somewhat thicker walled. 

All investigators of the morphologic characteristics of the genus Tempskya have formally or informally used stem diameter :as a basis for specific 
SYNOPSIS 33 

separation. However, as Arnold (1958) has pointed 

out, the use of diameter as a character trait ,always 

raises a question whether exceedingly large specimens that are otherwise similar to smaller stems 

may simply be indicative of very robust individuals. 

Thus, T. superba Arnold appears to be identical in 

all respects with T. grandis Read and Brown, but 

the stem diameter in T. superba is ·approximately 

twice that of T. grandis. Nevertheless, in the absence of data to the contrary, the writers are of the 

opinion that stem di,ameters are a valid criterion for 

distinguishing species. 

Earlier, Read and Brown (1937) expressed the 

opinion that stem diameter and length of internodes 

might correlate directly. At that time, Tempskya 

grandis and T. rossica were the only two largestemmed species known ( > 4 m·m in diameter) , and 

both of them are characterized by relatively short 

internodes. Similarly, T. knowltoni and T. minor 

were the only small-stemmed ( < 4 mm in diameter) 

types known, and both are characterized by relatively long internodes. T. wesselii is in stem size 

somewhat larger in general than T. knowltoni and 

T. ··minor, but as indicated els.ewhere, ~it is characterized by very long internodes comparable in length to 

those of T. zelleri n. sp. 

T. wymningensis is intel'lmediate in average diameter between T. grandis and T. superba, but it has 

short internodes. T. reesidei n. sp. has small ·stems 

and relatively long internodes, whereas T. zelleri 

n. sp., which also has s·mall stems, has very long 

internodes. It is thus apparent that there is no correlation between stem diameter and length of internodes (Arnold, 1945) . 

Roots.-The roots of all known species of Tempskya appear to be similar, if not identical. In most 

species the outer cortex is unknown. However, in T. 

minor and T. wesselii, several observers (Read and 

Brown, 1937; Arnold, 1945; Andrews and Kern, 

1947) have noted ran outer lacunar cortex (.pl. 9, 

fig. 3) as well as a well-defined epidermis bearing 

simple root hairs. We believe that these observations 

have been made on exceedingly well-preserved specimens and that the outer lacunar zone in the cortex 

is probably characteristic of all species. 

In general, the adventitious roots of all species 

parallel or subparallel the long axes of the stems. 

However, in one species, T. reesidei, a relatively 

high percentage of roots clearly do not parallel the 

courses of the stems (,pl. 3, fig. 1). The importance 

of this characteristic in the specific concept of T. 

reesidei can only be evaluated after ·material from 

many localities has become available. 

SYNOPSIS 

In an earlier report on Tempskya (Read and 

Brown, 1937) an effort was made to summarize the 

distinctions of the better known species. This grouping of salient characteristics seems to have been 

helpful to some of the investigators who have 

worked on Tempskya in more recent years. Accordingly, a new synopsis has been prepared which inc! udes the better known species of the genus. 

I. Individual stems of false trunk medium to large (5-15 mm) 

in cross-sectional diameter. The inner parenchymatous 

layer of the cortex containing continuous and (or) discontinuous bands of sclerenchyma. Much parenchyma in 

the xylem ring. False trunks have radial symmetry. 

A. Inner parenchymatous layer of cortex and exterior of pith contains a single discontinuous 

and irregular band of sclerenchyma. Internodes 

short, permitting much overlapping (3-5) of 

leaf bases. 

1. Individual stems, 10-15 mm in crosssection diameter ----------------- ________________ Tentpskya superba 

2. Individual stems· medium, 4-6 mm in 

cross-section diameter ___________ ·:.. 

________________ Tentpskya grandis 

B. Inner parenchymatous layer of cortex contains 

two bands of sclerenchyma separated by a continuous or discontinuous band of parenchyma. 

The outer bana of sclerenchyma is continuous, 

and the inner band may be either continuous 

or discontinuous. Exterior of pith does not contain a band of sclerenchyma. Internodes long 

to very long, permitting very slight to slight 

overlapping ( 1-3) of leaf bases. 

1. The two bands of sclerenchyma in the 

inner parenchymatous layer of cortex are connected locally by strands 

of sclerenchyma, giving an impression of "islands" of parenchyma surrounded by sclerenchyma. Internodes 

are long, permitting slight overlapping (2-3) of leaf bases ---------- ________________ Tentpskya reesidei 

2. The two bands of sclerenchyma in the 

inner parenchymatous layer of cortex are completely separated from 

each other by a continuous band of 

parenchyma. 

a. Internodes very long, permitting only very slight overlapping ( 1-2) of leaf bases. 

Individual stems 4.0-5.0 mm 

in cross-sectional diameter __ 

________ T entpskya wesselli 

b. Internodes medium in length, 

permitting slight overlapping (2-3) of leaf bases. Individual stems 6.0-8.0 mm 

in cross-sectional diameter __ 

___ Tentpskya wyontingensis 
34 NORTH AMERICAN SPECIES OF TEMPSKY A 

D 

FIGURE H.-Diagrammatic sketches of the stems of the 

well-known species of Tempskya. Cortical sclerenchyma and similar tissues in the pith are shown as 

black; xylem of the stele is shown by the dark 

stipple pattern; the parenchyma is shown by a light 

stipple pattern; and phloem and pericycle are shown 

by clear bands. All X 10 except I which is X 8. A, 

Tempskya zelleri. Adapted from slides of the type 

specimen. B, T. reesidei. Adapted from slides of the 

type specimen. C, T. minor. Adapted from Read and 

Brown, 1937, pl. 36, fig. 3, and slides of the type 

B 

E 

specimen. D, T. grandis. Adapted from Read and 

Brown, 1937, pl. 33, fig. 4, and slides of the type 

specimen. E, T. wyomingensis. Adapted from Arnold, 

1945, pl. 10, fig. 1, and slides of the type specimen. F, 

T. rossica. Adopted from Kidston and Gwynne-Vaughan, 1911, pl. 2, fig. 10. G, T. knowltoni. Adapted 

from Read and Brown, 1937, pl. 32, fig. 1, and slides 

of the type specimen. H, T. wesselii. Adapted from 

Arnold, 1945, pl. 8, fig. 1, and slides of the type 

specimen. I, T. superba. Adapted from Arnold, 1958, 

pl. 2, fig. 2, and slides of the type specimen. 
SYNOPSIS 35 

I 

FIGURE 11.-(Continued.) 
36 NORTH AMERICAN SPECIES OF TEMPSKY A 

II. Individual stems of false trunk small to medium <2.5-8.0 

mm) in cross-sectional diameter. The inner parenchymatous layer of the cortex does not contain continuous or 

discontinuous layers of sclerenchyma. Little parenchyma 

in the xylem ring. False trunks have either dorsiventral 

or radial symmetry. 

A. Individual stems and steles angular in cross section, approximately 3-8 mm in diameter. Internodes very long, permitting only very slight 

overlapping <1-2) of leaf bases -------------

--------------------- ______ Tempskya zelleri 

B. Individual stems and steles round to subround in 

cross section. Internodes long, permitting slight 

overlapping (2-3) of leaf bases. 

1. Petioles common in false trunks; stems 

approximately 2.0-3.5 mm in diameter. False trunks are dorsiventraL __ __________________ T empskya minor 

2. Petioles rare in false trunks. Stems are 

approximately 2.5-7.0 mm in diameter. False trunks are dorsiventral or 

radially symmetrical. 

a. False trunk dorsiventral. 

Xylem exarch .. Xylem ring 

containing little if any parenchyma. Stems are 2.5-3.5 

mm in diameter ---------- _______ Tempskya knowltoni 

b. False trunk radially symmetrical. Xylem exarch or possibly slightly immersed in 

some specimens. Xylem ring 

containing much parenchyma. Stems are 6.0'-7.0 

mm in diameter ---------- _________ Tempskya rossica 

SELECTED REFERENCES 

Publications that are cited in this paper and other publications in which Tempskya is mentioned or described are included here. Iteins marked with an asterisk ( *) contain 

descriptions and discussions of the genus Tempskya and its 

several species. 

Anderson, J. L., 1948, Cretaceous and Tertiary subsurface 

geology: Maryland Dept. Geology, Mines and Water Re~ 

sources Bull. 2, p. 1-113, app. p. 385-4.41. 

Andrews, H. N., Jr., 1943, Notes on the genus Tempskya: Am. 

Midland Naturalist, v. 29, no. 1, p. 133~136. 

--- 1947, Ancient plants and the world they lived in: 

Ithaca, N.Y., Comstock Publishing Co., 279 p. 

--- 1948, Fossil tree ferns of Idaho: Archaeology, v. 1, 

no. 4, p. 190-19·5, 8 figs. 

--- 1961, Studies in paleobotany, with a chapter on palynology by Charles J. Felix : New York, John Wiley and 

Sons, 487 p. 

*--- 1970, Filicophyta Incertae Sedis, in Andrews, H. N ., 

Jr., and others, Traite de Paleobotanique; time IV, 

fascicule 1, Filicophyta: Paris, Masson et Cie, p. 457-491. 

[In French.] 

*Andrews, H. N., and Kern, E. M., 1947, The Idaho Tempskyas 

and associated fossil plants: Missouri Bot. Garden Annals, 

v. 34. no. 2, p. 119-183, app. p. 185-186, pls. 15-27, 8 

text-figs. 

*Arnold, C. A., 1945, Silicified plant remains from the Mesozoic and Tertiary of western North America. I, Ferns: 

Michigan Acad. Sci., Arts and Letters Papers, 1944, v. 

30, p. 3-34. 

*--- 1958, A new Tempskya: Michigan Univ. Mus. Paleontology Contr., v. 14, no. 8, p. 133-142, 3 pls., 1 fig. 

Berry, E. W., 19lla, Correlation of the Potomac formations: 

Maryland Geol. Survey, Lower Cretaceous [Volume], 

p. 153-172. 

*--- 19llb, Systematic paleontology of the Lower Cretaceous deposits of Maryland; Plantae; Pteridophyta: Maryland Geol. Survey, Lower Cretaceous [Volume], p. 214-

312, pls. 12-41. 

--- 1929, The Coastal Plain deposits: Maryland Geol. 

Survey, Baltimore County [Volume], p. 200-2:17, 4 pls. 

Boodle, L. A., 189·5, Spores in a specimen of Tempskya (Endogenites): Ann. Botany, v. 9, 137-141, figs. 1-4. 

Boswell, P. G. H., 1929, Cretaceous System in Evans, J. W., 

Stubblefield, C. J ., and others, Handbook of the geology 

of Great Britain, a compilative work: London, Thomas 

Murby and Co., p. 388-389. 

Bowen, C. F., 1919, Anticlines in a part of the Musselshell 

Valley, Musselshell Meagher and Sweetgrass Counties, 

Montana: U.S. Geol. Survey Bull. 691-F, p. 185-209, 

pl. 25 . 

Bower, F. 0., 1926, The ferns (Filicales); v. 2, The Eusporangiatae and other relatively primitive ferns: London, 

Cambridge Univ. Press, 344 p., 580 figs. 

Brongniart, Adolphe, 1847a, Tableau des genres de vegetaux 

fossils consideres sous le point de vue de leur classification 

botanique et de leur disLribution geologique: Paris, Dictionnaire Univ. Histoire Nat., v. 13, p. 107. 

--- 1849b, Exposition chronologique des periodes de vegetation et des flores diverses que se sont succede a la surface 

de la terre: Annales Sci. Nat. (Botanique), 2d ser., v. 11, 

p. 285-338. (Not seen.) 

Bronn, H. G., 1848-49, Index paleontologicus: Stuttgart, E. 

Schweizerbart, 3 v. (See v. 1, p. 461.) 

Bronn, H. G., and Roemer, Ferdinand, 1851-5·2, Von den 

charakteristischen V ersteinerungen der zweiten Periode 

insbesondere. I. Pflanzon, in H. G. Bronn's Lethaea Geognostica: Stuttgart, E. Schweizerbart, v. 2, p. 20-43, pl. 28, 

fig. 8a, b, c. 

Brown, R. W., 1936, Field identification of the fossil ferns 

called Tempskya: Washington Acad. Sci. Jour., v. 26, no. 

2, p. 45.-52. 

--- 1950, Cretaceous plants from southwestern Colorado: 

U.S. Geol. Survey Prof. Paper 22'1-D, p. 45-66, pls. 9-12. 

Carpentier, Alfred, Decouverte de fragments de Fougeres fossiles du genre Tempskla Corda (emend. Kidston et 

Vaughan) a Glageon (Nord): Soc. Bot. France Bull., 

v. 16, p. 68-72, fig. 1. (Not seen.) 

--- 1927, La flore wealdienne de Feron-Glageon (Nord): 

Soc. geol. Nord Mem., v. 10, pt. 1, p. 1-1M, pls. 1-25. 

*Chandler, M. E. J., 1968, A new Tempskya from Kent: 

London, British Mus. (Nat. History) Bull., Geology, v. 

15, no. 4, p. 169-179, pls. 1-12. 
SELECTED REFERENCES 37 

Clark, W. B., Bibbins, A. B., and Berry, E. W., 1911, The 

Lower Cretaceous deposits of Maryland: Maryland Geol. 

Survey, Lower Cretaceous [Volume], p. 23-98, 10 pls. 

Cobban, W. A., 1951, Colorado shale of central and northwestern Montana and equivalent rocks of Black Hills: 

Am. Assoc. Petroleum Geologists Bull., v. 35, no. 10, p. 

2170-2198. 

Cobban, W. A., and Reeside, J. B., Jr., 1951, Lower Cretaceous 

ammonites in Colorado, Wyoming, and Montana: Am. 

Assoc. Petroleum Geologists Bull., v. 35, no. 8, p. 1892-

1893. 

--- 195i2a, Correlation of the Cretaceous formations of the 

Western Interior of the United States: Geol. Soc. America 

Bull., v. 63, no. 10, p. 1011-1044, 2 figs., 1 pl. 

--- 1952a, Frontier formation, Wyoming and adjacent 

areas: Am. Assoc. Petroleum Geologists Bull., v. 36, no. 

10, p. 1913-1961, 4 figs. 

Cobban, W. A., and others, 1959, Revision of Colorado Group 

on Sweetgrass Arch, Montana: Am. Assoc. Petroleum 

Geologists Bull., v. 43, no. 12, p. 2786-2796. 

':'Corda, A. J. C., 1845, Beitrage zur Flora der Vorwelt: Prague, 

J. G. Calve'sche, 128 p., 60 pls. (Seep. 81-82'.) 

--- 1846, [Pt.] H. Pflanzen, in Reuss, A. E., Die Versteinerungen der bohmischen Kreideformation: Stuttgart, E. 

Schweizerbart, v. 2, p. 81-96, pls. 46-50. (See p. 87, pl. 

47, fig. 7.) 

*Cotta, C. B., 1832, Die Dendrolithen in Beziehung auf ihren 

inneren Bau: Dresden, Arnoldische Buchhandlung, 89 p., 

19 pls. (See p. 37-44, ·pl. 8, figs. 4, 5.) 

Craig, L. C., and others, [Discussion of "Dakota Group of 

Colorado Plateau," by R. G. Young, 19·60]: Am. Assoc. 

Petroleum Geologists Bull., v. 45, no. 9, p. 1582-15·84, 1 

fig. 

Dane, C. H., and Bachman, G. 0., 1961, Preliminary geologic 

map of the southeastern part of New Mexico: U.S. Geol. 

Survey Misc. Geol. Inv. Map I-344. 

Darton, N. H., 1928a, "Red Beds" and associated formations 

in New Mexico: U.S. Geol. Survey Bull. 79'4, 356 p., 62 

pls., 173 figs. 

--- 1928b, Geologic map of New Mexico: U.S. Geol. Survey, 

scale 1:500,000. 

Delevoryas, Theodore, 1963, Morphology and evolution of 

fossil plants: New York, Holt, Rinehart and Winston, 

189 p. 

Dixon, Frederick, 1878, Geology of Sussex, or the geology 

and fossils of the Tertiary and Cretaceous formations of 

Sussex. New [second] edition. Revised and augmented by 

T. Rupert Jones: Brighton, 469 p., 64 pls. (See p. 142, 

144, 282. 

Dorf, Erling, 1952, Critical analysis of Cretaceous stratigraphy and paleobotany of Atlantic Coastal Plain: Am. 

Assoc. Petroleum Geologists Bull., v. 36, no. 11, p. 2'161-

2184, 4 figs. 

Dunker, Wilhelm, 1846, Monographie der norddeutschen Wealdenbildung. Ein Beitrag zur Geognosie und N aturgeschichte 

der Vorwelt: Braunschweig, 83 p., 21 pis. (See p. 17, 18, 

pl. 3, figs. 1, la, lb.) 

Eicher, D. L., 1958, The Thermopolis Shale in eastern Wyoming, in Wyoming Geol. Assoc. Guidebook 13th Ann. 

Field Conf., 1958, Powder River Basin: p. 79-83, 1 fig. 

Endo, S., 1926, On the genus Tempskya from Kii: Chikyu, v. 

6, p. 5-6. 

Engler, Adolf, and Prantl, K. A. E., 1902, Die naturlichen 

Pflanzenfamilian, Teil 1, Abt. 4: Leipzig, 808 p. (See 

p. 512.) 

Ettingshausen, Constantin von, 1852, Beitrag zur naheren 

Kenntniss der Flore der Wealdenperiode: Austria Geol. 

Reichsanst. Abh., v. 1, pt. 3, no. 2, 3·2 p., 5 pis. (See p. 

19.) 

--- 1854, Die Steinkohlenflora von Radnitz in Bohmen: 

Austria Geol. Reichsanst. Abh., v. 2, pt. 3, no. 3, 74 p., 

29 pls. (Seep. 47.) (Not seen.) 

Evans, J. W., ed., 19•18, Geology of the British Isles, by Boswell, P. G. H., and others: The Hague, M. Nijhoff, 354 p. 

(See p. 248.) 

*Feistmantel, Ottokar, 1874, Uber Baumfarrenreste der 

Bohmischen Steinkohlen-, Perm- und Kreideformation: K. 

Bohmischen Gesell. Wiss. (Prague) Abh., [1872], Folge 

6, Bd. 6, 30 p. (See p. 22.) Not seen. 

*Fitton, W. H., 1836, Observations on some of the strata between the Chalk and the Oxford oolite in the south-east 

of England: Geol. Soc. London Trans., ser. 2, v. 4, p. 

103-378, pls. 9·, 2'0, fig. 1. 

Foster, H. L., 1947, Paleozoic and Mesozoic stratigraphy of 

northern Gros Ventre Mountains and Mount Leidy Highlands, Teton County, Wyoming: Am. Assoc. Petroleum 

Geologists Bull., v. 31, no. 9, p. 1537-1593, 9 figs. 

Fritsch, Anton, and Bayer, Edvin, 1900, Studien im Gebiete 

der bohmischen Kreideformation; Palaeontologische U ntersuchungen der einzelnen Schichten; Perutzer Schichten : .. 

Archiv. naturwiss. Landesd. Bohmen, v. 11 no. 2, p. 1-184. 

Frizzell, D. L., 1954, Handbook of Cretaceous Foraminifera 

of Texas: Texas Univ., Bur. Econ. Geology Rept. Inv. 22, 

232 p. 

Giebel, C. G., 1852, Deutschlands Petrefacten: Leipzig, 7'06 p. 

(See Fossile Pflanzen, v. 1, p. 66.) 

Goeppert, H. R., 1864-1865, Die fossile Flora der permischen 

Formation: Palaeontographica, v. 12, 3.16 p. 64 pls. (See 

p. 44, 45.) 

Greene, W. D., 1957, Strange plants of the past: Mineralogist, 

v. 25, no. 5, p. 2.04-206, 208. 

Gutbier, C. A. von, 1849, Die Versteinerung~n des Rothliegenden in Sachsen: 30 p., 12 pls. (See p. 17.) 

Hirmer, Max, 1927, Handbuch der Palaobotanik: Munich and 

Berlin, R. Oldenbourg. v. 1, 708 p. (Seep. 681.) 

Hosius, August, and Marek, W. von der, 1880, Die Flora der 

westfalischen Kreideformation: Palaeontographica, v. 26, 

p. 125-241. (See p. 192 (68), pl. 39, figs. 161-163.) 

Katich, P. J., Jr., 1951, Recent evidence for Lower Cretaceous 

deposits in Colorado Plateau: Am. Assoc. Petroleum Geologists Bull., v. 35, no. 19, p. 2093-2094. 

Kidston, Robert, 1886, Catalogue of the Paleozoic plants in 

the Department of Geology and Paleontology, British 

Museum (Natural History): London, British Mus. (Nat. 

Hist.), 288 p. (See p. 11.) 

Kidston, Robert, and Gwynne-Vaughan, D. T., 1910, On the 

fossil genus Tempskya: British Assoc. Adv. Sci. Rept., 

Sheffield, p. 783. 

*--- 1911, On a new species of Tempskya from Russia: 

Russ. k. min. Gesell. Verb., v. 48, p. 1-20, pls. 1-3. 

KLepper, M. R., 19·50, A geologic reconnaissance of parts of 

Beaverhead and Madison Counties, Montana: U.S. Geol. 

Survey Bull. 969-C, p. 5·5-85, pl. 16 [.1951]. 

Knowlton, F. H., 1927, Plants of the past; a popular account 

of fossil plants: Princeton, Princeton Univ. Press, 275 

p., 90 figs. 
38 NORTH AMERICAN SPECIES OF TEMPSKY A 

Lasky, S. G., 194.7, Geology and ore deposits of the Little 

Hatchet Mountains, Hidalgo and Grant Counties, New 

Mexico: U.S. Geol. Survey Prof. Paper 208, 101 p., 27 

pls., 18 figs. 

Loeblich, A. R., and Tappan, H. N., 1946, New Washita 

Foraminifera: Jour. Paleontology, v. 20, no. 3, p. 2.38--258. 

--- 1964, Sarcodina, chiefly "Thecamoebians" and Foraminiferida, v. 1, in Moore, R. C., ed., Treatise on invertebrate 

paleontology, Part C, Protista 2: New York and Lawrence, 

Kans., Geol. Soc. America and Univ. Kansas Press, p. 

Cl-C510a, 399 figs. 

Longwell, C. R., 1928, Geology of the Muddy Mountains, 

Nevada: U.S. Geol. Survey Bull. 798, 152 p., 17 pls., 9 figs. 

--- 1949, Structure of the northern Muddy Mountain area, 

Nevada: Geol. Soc. America Bull., v. 60, no. 5 p. 92.3-

968, 11 pls., 14 figs. 

Love, J.D., Duncan, D. C., Bergquist, H. R., and Hoso, R. K., 

1948, Stratigraphic sections of Jurassic and Cretaceous 

rocks in the Jackson Hole area, northwestern Wyoming: 

Wyoming Geol. Survey Bull. 40, 48• p., 2 figs. 

Lozo, F. E., Jr., 1944, Biostratigraphic relations of some north 

Texas Trinity and Fredericksburg (Comanchean) Foraminifera: Am. Midland Naturalist, v. 31, no. 3, p. 513-582. 

McKnight, K. H., and Rigby, J. K., 1963, Lower Cretaceous 

Tempskya from eastern Utah [ abs.] : Geol. Soc. America 

Spec. Paper 73, p. 91. 

Mantell, G. A., 182·2, The fossils of the South Downs; or Illustrations of the geology of Sussex: London, 327 p., 42 pls. 

(See p. 42.) 

--- 1824, On some fossil vegetables from the strata of 

Tilgate Forest [in Sussex]: Geol. Soc. London Trans., 

ser. 2, v. 1, p. 421-424, pls. 45-47. (No authors names 

given.) 

--- 1827, Illustrations of the geology of Sussex; a general 

view of the geological relations of the southeastern part 

of England; with figures and descriptions of the fossils 

of Tilgate Forest: London, 92 p., 20 pls. (See p. 54, pl. 3, 

figs._ 1, 2, pl. 3 (so numbered in the book), fig. 5.) 

---1833, The geology of the South-East of England: London, 415 p., 7 pls. (See p. 236, pl. 1, figs. 4, 5, 7.) 

Martin, P. J., 1828, A geological memoir on a part of western 

Sussex: London, 100 p., 2 pls. (See p. 41.) 

Mineralogist, 1940, New species fossil fern Tempskya, Oregon: 

Mineralogist, v. 8, no. 10, p. 391-392. 

Morgenroth, Eduard, 1883, Die fossilen Pflanzenreste im Diluvium der Umgebung von Kamenz in Sachsen: Zeitschr. 

Gesammten Naturwiss., Halle, v. 45, (Fourth ser., v. 2, 

1883)' p. 271-318. 

Mortize, C. A., 19'53, Summary of the Cretaceous stratigraphy 

of southeastern Idaho and western Wyoming in Intermountain Assoc. Petroleum Geologists, Guide to the 

geology of northern Utah and southeastern Idaho, 4th 

annual field conference, 1953: Salt Lake City, Utah, p. 

63-72. 

Morris, John, 1854, A catalog of British fossils, comprising all 

the genera and species hitherto described; with references 

to their geological distribution and to the localities in 

which they have been found: 2d ed., London, 372 p. (See 

p. 8.) 

Peck, R. E., 1951, Nonmarine ostracodes-the subfamily Cyprideinae in the Rocky Mountain area: Jour. Paleontology, 

v. 25, no. 3,p. 307-320. 

--- 1957, North American Mesozoic Charophyta: U.S. Geol. 

Survey Prof. Paper 294-A, p. 1-44, pls. 1-8, 7 figs. 

Pelourde, Fernand, 1941, Paleontologie Vegetale, cryptogames 

cellulaires et crytogames vasculaires: Paris, 0. Doin, 360 

p. (See p. 316.) 

Petters, V., 1954, Typical foraminiferal horizons in the Lower 

Cretaceous of Colombia, S. A.: Cushman Found. Foram. 

Research Contr., v. 5, pt. 3, p. 128-137. 

Pettko, Johann von, 1850, [Tubicaulis von Ilia bei Chemnitz]: 

Haidinger naturwiss. Abh. 3, p. 163-16,9·. (See p. 169, 

pl. 1.) (Not seen.) 

Posthumus, Oene, 1924, Some remarks concerning the classification and the nomenclature of the Inversicatenales: Akad. 

Wetensch., Amsterdam, Proc., v. 27, p. 834-838. (See 

p. 836.) (Not seen.) 

--- comp., 19·31, Catalogue of the fossil remains described as 

fern stems and petioles: Malang, Java, N. J. Jahn, 234 

p. (See p. 3, 5, 210'-214.) 

Prigorovsky, M. M., 1914, Esquisse geologique des monts 

Mougodjars et des parties voisines des steppes de Tourgai 

et de l'Oural: Russia, Geol. Komitet Isvest., v. 3-3, pt. 2, 

p. 889'-928, pl. 35a. (In Russian; summary in French.) 

Read, C. B., 1939, The evolution of habit in Tempskya: 

Lloydia, v. 2, p. 63-72, 6 figs. 

Read, C. B., and Ash, S. R., 1961a, The stratigraphic significance of the fossil fern Tempskya in the western 

states [abs.] in New Mexico Geol. Soc., Guidebook of the 

Albuquerque Country, 12th Field Conf., Oct. 6-8, 1961: 

Socorro, N. Mexico Bur. Mines and Mineral Resources, 

199 p. 

---1961b, Stratigraphic significance of the Cretaceous fern 

Tempskya in the western conterminous United States: 

U.S. Geol. Survey Prof. Paper 424-D, p. D250-D25·4, 

figs. 382.1-382.4. 

*Read, C. B., and Brown, R. W., 19·37, American Cretaceous 

ferns of the genus Tempskya: U.S. Geol. Survey Prof. 

Paper 186-F, p. 105-131, pis. 27-43, figs. 2-6. 

Reeside, J. B., Jr., 1944, Map showing thickness and general 

character of the Cretaceous deposits in the Western 

Interior of the United States: U.S. Geol. Survey Oil and 

Gas Inv. Map OM-10. 

Reeside, J. B., Jr., and Cobban, W. A., 1960, Studies of the 

Mowry Shale (Cretaceous) and contemporary formations 

in the United States and Canada: U.S. Geol. Survey Prof. 

Paper 355, 12'6 p., 58 pis., 80 figs. 

Reeside, J. B., Jr., and Weymouth, A. A., 1931, Mollusks from 

the Aspen Shale (Cretaceous) of southwestern Wyoming: 

U.S. Natl. Mus. Proc., v. 78, art. 17, 24 p., 4 pls. 

Richards, H. G., Groot, J. J., and Germeroth, R. M., 19·57, 

Cretaceous and Tertiary geology of New Jersey, Delaware 

and Maryland, Field Trip no. 6, in Geol. Soc. America, 

Guidebook for field trips, Atlantic City Meeting, 195,7: p. 

183-216, 7 figs. 

Rubey, W. W., and Callaghan, Eugene, 1936, Magnesite and 

brucite, in Hewett, D. F., and others, Mineral resources of 

the region around Boulder Dam: U.S. Geol. Survey Bull. 

871, p. 113-143. 
SELECTED REFERENCES 39 

Sahni, B., 1928, On Clepsydropsis australis, a zygopterid treefern with a Tempskya-like false stem, from the Carboniferous rocks of Australia: Royal Soc., London, Philos. Trans. 

ser. B, v. 217, p. 1-37, pis. 1-6. 

Sample, C. H., 1932, Cribratina, a new genus of Foraminifera 

from the Comanchean of Texas: Am. Midland Naturalist, 

v. 13, no. 5, p. 319-323, pl. 30. 

*Schenk, August, 1871, Beitrage zur Flora der Vorwelt; IV, 

Die fossile Flora der nordwestdeutchsen W ealdenformation: Palaeontographica, v. 19, p. 203-262, pis. 42, 43. 

Schimper, W. P., 1869-74, Traite de paleontologie vegetale, ou 

la flore du monde primitif daus ses rapports avec los 

formations geologiques et la Flore du Monde actual: Paris, 

3 v. and atlas, 110 pis. (See v. 1, p. 697, 698; v. 3, p. 5·30.) 

--- 1880, Palaeophytologie, in Zittel, K. A., Handbuch der 

Palaeontologi: Munich and Leipzig, R. Oldenbourg, Abt. 

2, Lieferung 2, p. 153-232. (See pl. 2, p. 151.) 

Schultz, A. R., 1914, Geology and geography of a portion of 

Lincoln County, Wyoming: U.S. Geol. Survey Bull. 543, 

141 p., 11 pls. 

*Seward, A. C., 1894-95, Catalogue of the Mesozoic plants 

in the Department of Geology, British Museum (Natural 

History). The Wealden flora: London, British Mus. (Nat. 

Hist.), 2 v., 31 pls. (See v. 1, p. 148-159.) 

--- 1923, The use of the microscope in palaeobotanical research: Jour. Royal Micros. Soc., 1923, p. 299-302, pl. 

11. (Not seen.) 

*--- 1924, On a new species of Tempskya from Montana, 

Tempskya knowltoni, sp. nov.: Ann. Botany, v. 38, p. 

485-507, fig~ 1-3, pls. 16, 17. 

Shawe, D. R., Simmons, G. C., and Archbold, N. L·., 1968, 

Stratigraphy of Slick Rock district and vicinity, San 

Migue·l and Dolores Coontie:s, Colorado: U.S. Geol. Survey Prof. Paper 576-A, 108 p. 

Simmons, G. C., 1957, Contact of Burro Canyon Formation 

with Dakota Sandstone, Slick Roek District, Colorado, 

and correlation of Burro Canyon Formation: Am. Assoc. 

Petroleum Geologists Bull., v. 41, no. 11, p. 2519-252.9, 

3 figs. 

Skolnick, Herbert, 195Sa, Lower Cretaceous Foraminifera of 

the Black Hills area: Jour. Paleontology, v. 32, no. 2, 

p. 275-285, pls. 36-38, 1 fig. 

---1958b, Stratigraphy of some Lower Cretaceous rocks 

of Black Hills area: Am. Assoc. Petroleum Geologists 

Bull., v. 42, no. 4, p. 787-815, 18 figs .. 

Spangler, W. B., and Peterson, J. J., 19·50, Geology of Atlantic 

Coastal Plain in New Jersey, Delaware, Maryland, and 

Virginia: Am. Assoc. Petroleum Geologists Bull., v. 34, 

no. 1, p. 1-99, 1 pl., 24 figs. 

*Stenzel, K. G. W., 1897, Verkieselte Fame von Kamenz in 

Sac.hsen: K. Mineralog.-Geol. und Praehist. Mus. Dresden 

Mitt., no. 13, p. 1-24, pis. 1-3. (See p. 3.) 

Sterzel, J. T., 1893, Die Flora des Rothlie•genden im Plauenschen Grunde bei Dresden: K. Sachsis.che Gesell. Wiss., 

Math.-Phys. Klasse Abh., v. 19, 172 p. (See p. 129, pl. 

12, figs. 8, 9.) (Not seen.) 

[Stokes, Charles, and Webb, P. B.], 1824, Descriptions of 

some fossil vegetables of the Tilgate Forest in Sussex: 

Geol. Soc. London Trans., 2d ser., v. 1, p. 423-426, pls. 

45-4 7. (No authors names given.) 

Stokes, W. L., 1944, Morrison Formation and related deposits 

in and adjacent to the Colorado Plateau: Geol. Soc. 

America Bull., v. 55, no. 8, p. 951-992, 5 p-is., 5 figs. 

--- 1952, Lower Cretaceous in Colorado Plateau: Am. 

Assoc. Petroleum Geologi.sts Bull., v. 36, no. 9, p. 1766-

1776, 3 figs. 

---1955, Non-marine Late Jurass,ic and Early Cretaceous 

formation, in Wyoming Geol. Assoc., Guidebook, 10th 

Ann. Field Conf., 1955, Green River Basin: p. 80-84. 

*Stopes, M. C., 1915, Catalogue of the Mesozoic plants in 

the British Museum (Natural History). The Cretaceous 

flora, Part 2, Lower Greensand (Aptian) plants of Britain: London, British Museum (Nat. History), 360 p., 

32 pls. (See p·. 13, 19-21, text-figs. 2-5.) 

Strobell, J. D., Jr., 1956, Geology of the Carrizo Mountains 

area in northeaste·rn Arizona and northwestern New 

Mexico: U.S. Geol. Survey Oil and Gas lnv. Map OM160, 2 sh.eets. 

Tidewell, W. D., and Hebbert, Naomi, 1972, Tempskya from 

the Cedar Mountain Formation near Moab, Utah [abs.]: 

Geol. Soc. America Abs. with pro·grams, v. 4, no. 6, p. 

417-418. 

Unger, Franz, 1845, Synopsis plantarum fossilium: Leipzig, 

330 p. (See p. 107). 

---1841-47, Chloris protogaea [in 10 parts]: Leip·zig, 149 

p., 50 pis. (See p. 52). Not seen. 

--- 1850, Genera et specie's plantarum fos.silium: Vienna, 

627 p. (See p. 201.) 

Veatch, A. C., 1907, Geography and geology of a portion of 

southwestern Wyoming, with special reference to coal 

and oil: U.S. Geol. S.urvey Prof. Paper 56, 178 p., 26 p-is. 

*Velenovsky, Josef, 1888, Die Fame der Bohmischen Kreideformation: K. Bohmiche Gesell. Wissen. Abh., Folge 7, 

v. 2, no. 8, 32 p., 6 pls. (Seep. 23.) 

Vokes, H. E., 1948, Cretaceous Mollusca from depths of 4875 

to 4885 feet in the Maryland E·sso well: Maryland Dept. 

Geology, Mines and Water Resources Bull. 2, p. 126-

151, pls. 3-4. 

--- 1957, Geography and geology of Maryland: Maryland 

Dept. Geology, Mines and Water Resources Bull. 19, 243 

p., 28 pls., 32 figs. 

West, W. R., 1968, Petrified wood in North Carolina.: Garolina Tips, v. 31, no. 9, p. 1-2, 2 figs. 

--- 1970, Tempskya in North Carolina: Lapidary Jour., v. 

23, no. 11, p. 155·2-1556, figs. 1-9. 

Wieland, G. R., 1922, [Progress of cycadophyte investigation], 

in Carnegie Inst. Washington Year Book No. 20, p. 452-

457. 

Yen, T.-C., 1952, Age of the Bear River Formation, Wyoming: 

Geol. Soc. America Bull., v. 63, no. 8, p. 757-764. 

--- 1954, [Discussion: Age of the Bear River Formation]: 

Am. Assoc. Petroleum Geologists Bull., v. 38, no. 11, p. 

2412-2413. 

Young, R. G., 1960, Dakota group of Colorado Plateau: Am. 

Assoc. Petroleum Geologists Bull., v. 44, no. 2, p. 156-194, 

20 figs. 

Zeller, R. A., Jr., 1958a, Reconnaissance geologic ma.p of 

Dog Mountains quadrangle: New Mexico Bur. Mines and 

Mineral Resources, Geol. Map 8, scale 1: 62,500. 
40 NORTH AMERICAN SPECIES OF TEMPSKY A 

1958b, The geology of the Big Hatchet Peak quadrangle, Hidalgo County, New Mexico: Univ. Galif., Los 

Angeles, Unpub. Ph.D. dissert., 260 p., 7 pls., 1 fig. 

--- 1958c, Preliminary composite stratigraphic section, 

Big Hatchet Peak quadvangle, Hidalgo County, southwestern New Mexico, in Roswell, Geol. Soc. Guidebook, 

11th Field Conf., The Hatchet Mountains and the Cooks 

Range-Florida Mountain areas, Grant, Hidalgo and Luna 

Counties, southwestern New Mexico May 14-16, 1958: 

p. 10. 

--- 1965, Stratigraphy of the Big Hatchet Mountains area, 

New Mexico: New Mexico Bur. Mines and Mineral Resources, Mem. 16, 128 p., 6 pls., 18 figs. 

Z·eller, R. A., Jr., and Alper, A. M., 1965, Geology of the 

Walnut Wells quadrangle, Hidalgo County, New Mexico: 

New Mexico Bur. Mines and Mineral Resources Bull. 84, 

105 p., 2 pls., 13 figs. 

Zeller, R. A., Jr., and Read, C. B., 1956, Occrurrence of 

Tempskya minor in strata of Albian age in southwe·stern 

New Mexico [abs.]: Geol. Soc. America Bull., v. 67, no. 

12, pt. 2, p. 1804. 
INDEX 

[Italic page numbers indicate descriptions and major references] 

Page 

A 

Acknowledgments --------------------- 2 

Aclistochara mundula ----------------- 11 

ActeoneUa sp ------------------------ 20 

Adventitious roots -------------------- 23 

Age of Tempskya-bearing rocks, New 

Mexico ------------------- 16 

Alamo Hueco Mountains (N. Mex.) ____ 17 

Albian Age ----------- 1, 5, 6, 9, 10, 11, 12, 13, 

14,1~ 18,2~21,22 

Ammonite ---------------------------·· 20 

Anatomical organization -------------- 23 

Anchura mudgeana ------------------- 21 

Animas Mountains (N. Mex.) ------ 1, 17, 18, 

21, 22,28 

Anomia sp --------------------------- 21 

Aptian Age -------------------- 12, 13, 14, 17 

Aptyxella (Nerinoides) n. sp --------- 20 

Area sp ------------------------------ 20 

Arundel Formation ------------------- 14 

Aspen Shale (Idaho) ----------------- 9, 11 

Aspen Shale (Wyo.) ------------- 4, 9, 14, 15 

Atlantic Coastal Plain area specimens __ 19 

australis, Clepsydropsis --------------- 6 

B 

barbara, Todea ----------------------- 5 

Baseline Sandstone ------------------- 11 

basiniformis, Corbula -----------------· 22 

Bear River Formation (Wyo.) ___ 9, 10, 11, 15 

Big Hatchet Mountains 

(N. Mex.) ---------- 1, 17, 18,31 

Biota, age ---------------------------- 22 

Black Hills (S. Dak.) ----------------- 14 

Blackleaf Formation ------------------ 6 

Brachydontes sp ---------------------- 20 

Breviarca sp ------------------------- 20 Burro Canyon Formation (Utah) _____ 12 

c 

Cadulus sp --------------------------- 21,22 

Ca_mptonectes inconspicuus ------------ 21 

Cardium kansasense ------------------- 21 

Carrizo Mountains ------------------- 2 

Cassiope sp -------------------------- 20 

caurinus, Melampus ------------------- 11 

Cedar Mountain Formation (Utah) ___ 11 

Cenomanian Age ---------------- 10, 13, 14,22 

Cephalopod --------------------------- 21, 22 

Cerithium pecoense ------------------- 20 

Chadron Formation (Nebr.) ---------- 14 

Chara stantoni ------------------------ 11 

Charophytes -------------------------- 11, 12 

Chinle Formation --------------------- 14 

Cinulia ------------------------------- 21 

Classificatory viewpoints -------------- 3, 4 

Clavator harrisi ----------------------- 11 

Clepsydropsis australis ---------------- 6 

Cloverly Formation (Wyo. 

and Mont.) ------------ 11, 12, 15 

Coal beds ---------------------------- 10,12 

Colorado Group (undifferentiated) 

(Mont.) ------------------

Page 

6 

Comparisons of species of Tempskya ___ 31 

Conglomerate ------------------------- 17,22 

Coniobasis ortmanni ------------------ 11 

Corbula basiniformis --------------··--- 22 

sp -------------------------------- 21 

Cortex, morphological details ---------- 32 

Cowboy Spring Formation ------------ 17,22 

crenulata, Hemitelia ------------------- 5 

Cretaceous stratigraphy --------------- 17 

Cribratina texana --------------- 2, 18, 21,22 

Crossbedding, fluvial type ------------- 13 

Cycad fragments --------------------- 15 

Cycadeoidea --------------------------- 14 

Cymbophora sp ----------------------- 21 

Cyprimeria gigantea ------------------- 21 

D 

Dakota Sandstone, Arizona ----------- 14 

Colorado ------------------------- 12 

New Mexico ---------------------- 1!,15 

Utah ----------------------------- 12 

Dentalium sp ------------------------- 21,22 

Depositional environment, continentaL__ 18 

nearshore ------------------------- 20 

Devils River Limestone (Georgetown) -- 20 

Dicksonia fibrosa --------------------- 5 

Dicotyledonae ------------------------- 13 

Dinosaur remains ------------------ 11, 14,15 

Diplodon n. sp ----------------------- 11 

Dorsiventral growth ---------23, 24, 25, 30, 31 

douglassi, Protelliptio ----------------- 12 

Drepanochilus kiowana ---------------- 22 

E 

(Echinobathyra) n. sp., Pyrazus ------ 20 

Edwards Formation (Tex.) ----------- 20 

emoryi, Trigonia ---------------------- 22 

endlichi, Lioplax ---------------------- 11 

Endogenites erosa --------------------- 2, 3 

Engonoceras serpentinum ----------- 20, 21, 22 

Epidermal hairs ---------------------- 25 

erosa, Endogenites -------------------- 2, 3 

Tempskya ------------------------ 3, 6 

Eupora onestae ----------------------- 12 

European faunal sequence ------------ 16 

Exogyra sp --------------------------- 22 

F 

False trunks ------------------------- 23, 28 

symmetry ------------------------ 24, 31 

terminal parts ------------------- 24 

farri, Lampsilis ---------------------- 12 

fibrosa, Dicksonia --------------------- 5 

Fish teeth and bones ----------------- 11 

Fluid transportation ----------------- 24 

Foraminifera ------------------- 10, 13, 21,22 

Fredericksburg age ------------------- 17,20 

Fresh water, mollusks ---------------- 10 

ostracodes ----------------------- 11 

Frontier Formation (Wyo.) ----- 9, 10, 11, 15 

Page 

G 

Gannett Group (Wyo. and Mont.) ____ 11, 12 

Gastroliths --------------------------- 15 

Gastropods ----------------- 11, 13, 21(), 21, 22 

geminata, Nerinea -------------------- 20 

gigantea, Cyprimeria ------------------ 21 

glabra, Nerinea gem:inata ------------- 20 

Gleicheniaceae _________ - -------------- 4 

Glen Rose age ------------------------ 17 

grandis, Tempskya ----- 2, 4, 5, 6, 9, 27, '31, 82, 

33, 34; pl. 10 

Graneros Shale (S. Dak.) ------------ 14 

Growth habit --------------------- 8, 4, 5, 24 

Gryphaea ----------------------------- 12 

H 

hamili, Unio ------------------------- 11 

harrisi, Clavator --------------------- 11 

Helix sp ----------------------------- 11 

Hell-to-Finish Formation ------------- 17 

Hemitelia crenulata ------------------- 5 

smithii --------------------------- 5 

History of investigations of Tempskya__ 2 

inconspicuus, Camptonectes ----------- 21 

In-place specimens ------------------- 6 

Introduction 

K 

kansasense, Cardium 

kansasensis, TurriteUa ----------------

Key to species --=----------------------

21 

22 

88 

kiowana, Drepanochilus --------------- 22 

knowltoni, Tempskya ____ 2, 4, 6, 12, 24, 25, 31, 

82, 88, 34, 86; pl. 8 

Kootenai Formation ---------------- 6, 11, 12 

L 

La SaJ Mountains (Utah) 12 

Lampsilis farri _ ·------------------~- 12 

Leaf emergence ----------------------27,31 

Leaf traces, abundance --------------- 25 

morphological details ------------- 28 

Leptosporangiatae -------------------- 8, 4 

Lima sp ----------------------------- 21 

Lioplax endlichi ----------------------- 11 

Little Hatchet Mountains 

(N. Mex.) --------------- 17 

London Clay (Great Britain) --------- 6 

Lopha quadriplicata ------------------ 21, 22 

Lower Greensand (Great Britain) ---- 8, 6 

Loxsomaceae ------------------------- 4 

Lunatia ------------------------------ 21 

Lymnaea (Pleurolimnaea) n. sp ------ 11 

M 

McEJmo Formation 

macrocaula, Tempskya 

41 

12 

8 
42 

Page 

marginatus, Porosus ------------------ 2 

Marine aspect, sandstone ------------- 13 

Marine invertebrate faunas ____ 1, 9, 13, 14, 16, 

17, 18, 20, 22 

Mascal age --------------------------- 15 

Melampus caurinus ------------------- 11 

Mesaverde Group --------------------- 15 

Metacyris ---------------------------- 11 

Mexican geosyncline area specimens __ 18 

microrrhiza, Tempskya ---------------- 3 

Microtaenia paucifolia ---------------- 11 

minor, Tempskya ------ 1, 2, 4, 9, 10, 11, 15, 31, 

32, 33, 34, 36; pl. 9 

Moenkopi Sandstone (Ariz.) ---------- 14 

Mojado Formation (N. Mex.) __ 2, 13, 17, 28,31 

biota, Animas Mountains --------- 21 

Mojado Pass ----------------- 20 

montanensis, Viviparus --------------- 11 

Morrison Formation ------------ 11, 12, 13, 15 

Mowry Shale ---------------------- 9, 10, 15 

mudgeana, Anchura ------------------- 21 

mundula, Aclistochara ---------------- 11 

Musculiopsis sp 11 

N 

Neithea texana ----------------------- 21 

Neocomian Age ----------------------- 14 

Neogastroplites ---------------------- 6, 9, 10 

Nerinea geminata --------------------- 20 

geminata glabra ------------------ 20 

shumlensis ----------------------- 20 

sp ------------------------------- 20 

(Nerinoides) n. sp., Aptyxella -------- 20 

Nerita sp ----------------------------- 20 

( Theilostyla) sp ______ ------------ 20 

Newcastle Sandstone ----------------- 10 

Nucula sp 21 

0 

Occurrences of Tempskya in the United 

States ------------------- 6 

Oligocene age ------------------------- 14 

ortmanni, Coniobasis ------------------ 11 

Ostrea perversa ----------------------- 20,21 

sp ------------------------------- 20 

Overton Fanglomerate ---------------- 10, 11 

p 

Paleocene age ------------------------ 15 

Patapsco Formation (Md.) ---------- 3,13 

paucifolia, Microtaenia ---------------- 11 

pawpawensis, Polychasmina ----------- 21 

pecoense, Cerithium ------------------- 20 

Pyrazus -------------------------- 20 

Pelecypods ------------------ 11, 12, 20, 21,22 

perversa, Ostrea ----------------------20, 21 

Petrified wood ------------------------ 14 

Photosynthesis ----------------------- 24 

Phthoropterides ----------------------- 3 

Physa usitata ------------------------- 11 

Pinyon Conglomerate ----------------- 15 

Planorbis praecursoris ----------------- 11 

Pleistocene age ----------------------- 14 

INDEX 

Page 

(Pleurolimnaea) n. sp., Lymnaea ----- 11 

Plicatula sp -------------------------- 20, 21 

Polychasmina pawpawensis ----------- 21 

Porosus marginatus ------------------- 2 

Postdepositional deformation ---------- 29 

Potomac Group ----------------------- 13, 14 

praecursoris, Planorbis ----'------------ 11 

Protelliptio douglassi ------------------ 12 

Protocardia texana ----------------- 20, 21,22 

Protopteris --------------------------- 3 

Pseudonerinea sp --------------------- 20 

pulchra, Tempskya -------------------- 3 

Purgatoire Formation (N. Mex.) ------ 20 

Pyrazus (Echinobathyra) sp ---------- 20 

pecoense ------------------------- 20 

Q 

quadriplicata, Lopha ------------------ 21,22 

Quaternary age ----------------------- 14, 15 

R 

Raritan Formation 13 

Reconstructions of growth habit ------ 24 

reesidei, Tempskya __ 1, 13, 22, 24,25, 28, 29, 30, 

3,1, 32, 33, 34; pls. 1-4; figs. 7-9 

Reworked specimens ------··----------- 14 

Rocky Mountain geosyncline area 

specimens ---------------- 6 

rossica, Tempskya __ 3, 4, 31, 32, 33, 34, 36; pl. 8 

s 

Scaphopods --------------------------- 21,22 

schimperi, Tempskya ------------------ 3 

Schizaeaceae -------------------------- 4 

Sedimentary loading, preservation ____ 29 

Selected references -------------------- 36 

Senonian Age ------------------------ 5 

seriatimgranulata, Turritella ---------- 20,21 

serpentinum, Engonoceras --------- 20, 21, 22 

Serpula sp --------------------------- 21 

shumlensis, Nerinea ------------------- 20 

Sierra Rica --------------------------- 17 

Skull Creek Shale --------------------- 10 

smithii, Hemitelia --------------------- 5 

Soil, fossil ---------------------------- 18 

stantoni, Chara ----------------------- 11 

Stems, characteristics ----------------- 23,29 

diameter ------------------------- 32 

dichotomy ------------------------ 23,25 

functional distance ---------------- 25 

Stone cells --------------------------- 32 

Stratigraphy of the Tempskya-bearing 

Rocks, New Mexico ------ 16 

superba, Tempskya ____ 2, 5, 31, 32, 33, 34; pl. 13 

Synopsis ----------------------------- 33 

Systematic descriptions --------------- 22 

T 

Tellina sp ---------------------------- 20,21 

Tempskya ---------------------------"' 22 

erosa ----------------------------- 3, 6 

grandis ------------ 2, 4, 5, 6, 9, 27, 31, 32, 

33 34; pl. 10 

Page 

knowltoni ----------- 2, 4, 6, 12, 24, 25, 31, 

32, 33, 34, 36; pl. 8 

macrocaula ----------------------- 3 

microrrhiza ----------------------- 3 

minor --------------- 1, 2, 4, 9, 10, 11, 15, 

31, 32, 33, 34, 36; pl. 9 

pulchra --------------------------- 3 

range ---------------------------- 11 

reesidei ---- 1, 13, 22, 24, 25, 28, 29, 30, 31, 

32, 33, 34; pls. 1-4; figs. 7-9 

rossica ------------- 3, 4, 31, 32, 33, 34, 36 

schimperi ------------------------- 3 

superba --------- 2, 5, 31, 32, 33, 34; pl. 13 

wesselii ------------- 2, 5, 6, 24, 27, 31, 32, 

33, 34; pl. 12 

whitei --------------------- 3, 4, 5, 13, 31 

wyomingensis ------------- 2, 5, 15, 31, 32, 

33, 34; pl. 11 

zelleri ______ 1, 13, 18, 20, 22, 24, 28, 30, 31, 

32, 33, 34, 36; pls. 5-7; fig. 10 

sp -------------------- 6, 9, 10, 12, 14, 15 

Tempskyaceae ------------------------ 4 

texana, Cribratina -------------- 2, 18, 21,22 

Neithea -------------------------- 21 

Protocardia -------------------- 20, 21, 22 

Texas Coastal Plain faunal sequence ___ 16 

( Theilostyla) sp., Nerita -------------- 20 

Thermopolis Shale (Wyo.) --------- 10, 14, 15 

Todea barbara ------------------------ 5 

Trigonia emoryi ----------------------- 22 

Trinity age -------------------------- 11 

Turonian Age ------------------------ 5 

Turritella kansasensis ---------------- 22 

seriatimgranulata ----------------- 20, 21 

u 

U-Bar Formation 17 

Unconformities ----------------------- 17, 22 

Unio hamili --------------------------- 11 

vetustus -------------------------- 11 

sp -------------------------------

usitata, Physa ------------------------

v 

11 

11 

vetustus, Unio ------------------------ 11 

Viviparus montanensis ---------------- 11 

w 

Washita age -------------------- 18, 20, 21, 22 

Wayan Formation (Idaho) ------------ 4, 9 

Wealden flora (England) ------------- 14 

wesselii, Tempslcya ------ 2, 5, 6, 24, 27, 31, 32, 

33, 34; pls. 10, 12 

whitei, Tempskya -------------- 3, 4, 5, 13, 31 

Willow Tank Formation (Nev.) ------- 10 

Woodbine Formation (Tex.) ---------- 20 

Woolwich Beds (Great Britain) ------ 6 

Worm -------------------------------- 21 

wyomingensis, Tempskya ------ 2, 5, 15, 31, 32, 

33, 34; pl. 11 

Y,Z 

Yoldia sp ----------------------------- 21 

zelleri, Tempskya ------ 1, 13, 18, 20, 22, 24, 28, 

30, 31, 32, 33, 34, 36; pls. 5-7; fig. 10 

-t< U.S. GOVERNMENT PRINTING OFFICE: 1975 0-211-319/37 
PLATES 1-13 

Contact photographs of the plates in this report are available, at 

cost, from U.S. Geological Survey Library, Federal Center, 

Denver, Colorado 80225 
PLATE 1 

FIGURES 1, 2. Tempskya reesidei Ash and Read, n. sp. (p. 2.5). 

From USGS fossil plant locality 9703. 

1. Cross section of the false trunk of the holotype showing the radial distribution of stem.s. The section is 

also shown in figure 7. Note that the stems are cut transversely in the central part of the false trunk 

whereas they are cut rather obliquely near the exterior. USNM 167546f, X 3/4. 

2. Two stems and associated leaf traces in the central part of the false trunk. A petiole has just separated 

from the left-hand stem, and a leaf trace is in an advanced stage of separating from the same stem, 

as indicated by the protuberance that has formed on the stem. A leaf trace that is nearly free is associated with the right-hand stem. The pronounced thinning of the stele in the same stem indicate·s 

that another leaf trace is in the process of forming. The "islands" of parenchyma in the inner cortex 

show as light irregularly shaped areas just outside of the steles. A few adventitious roots that are 

randomly oriented are noticeable in the picture. Slide USNM 167546a, X 5. 
GEOLOGICAL SURVEY PROFESSIONAL PAPER 874 PLATE I 

TEMPSKYA REESIDEI ASH AND READ, N. SP. 
PLATE 2 

Tempskya reesidei Ash and Read, n. sp. (p. 25). 

From USGS fossil plant locality 9703. 

Cross section a short distance away from the center of the false trunk. Here the 

stems are somewhat obliquely oriented, and the petioles are at a more oblique angle. 

Slide USNM 167546b, X 5. 
GEOLOGICAL SURVEY PROFESSIONAL PAPER 87-4 PLATE 2 

TEMPSKYA REESIDEI ASH AND READ, N. SP. 
PLATE 3 

FIGURES 1-3. Tempskya reesidei Ash and Read, n. sp. (p. 25) . 

From USGS fossil plant locality 9703. 

1. Cross section of two stems which are in the process of dividing. A leaf trace has started to separate 

from the left-hand stem, whereas a free petiole has just formed above the right-hand stem, and a leaf 

trace has begun to form on the same stem. The "islands" of parenchyma in the inner cortex that are typical of this species are clearly visible in some places. Note, especially in the upper right-hand corner, 

that the long axes of some of the roots extend horizontally or at random, rather than vertically as they 

do typically in T. zelleri and other species of Tempskya. Slide USNM 167546c, X 10. 

2. A stem that has just begun to divide into two stems. The process of dividing has not progressed as far 

in this example as in the stem shown in figure 1, so the stem is only slightly bilobed. A leaf trace has 

started to form from the right-hand lobe and a free petiole is just above the narrowed part of the stem. 

It probably arose from this same stem at a lower level. In most of this view, the long axes of the 

adventitious roots are oriented vertically, although a few can be seen that are randomly oriented. Slide 

USNM 167546d, X 10. 

3. The basal part of the false trunk of the paratype. This is a view of the side opposite that shown in 

figure 8. Compare with the picture of the holotype of T. knowltoni given by Seward (1924, pl. 16, fig. 

1). USNM 167547, about X %. 
GEOLOGICAL SURVEY PROFESSIONAL PAPER 874 PLATE 3 

1 

2 

TEMPSKY A REESIDEI ASH AND READ, N. SP. 
PLATE 4 

Tempskya reesidei Ash and Read, n. sp. (p. 25). 

From USGS fossil plant locality 9703. 

A stem and two associated leaf traces. The leaf trace in the upper left is nearly free, whereas the other 

is in a much less advanced s·tage of departure, and the leaf gap in the stele is beginning to close. Note that 

the stelar cells in the stem are cut transversely, whereas those in the leaf traces are cut on oblique angle. 

The "islands" of parenchyma surrounded by sclerenchyma in the inner cortex of the stem are clearly visible 

in this section. e, approximate position of the epidermal area; ph, phloem. Slide USNM 167546e, X 25. 
GEOLOGICAL SURVEY PROFESSIONAL PAPER 874 PLATE 4 

TEMPSKY A REESIDEI ASH AND READ, N. SP. 
PLATE 5 

Tempskya zelleri Ash and Read, n. sp. (p. 28). 

From USGS fossil plant locality 9702. 

General view of part of the false trunk of the holotype showing the distribution and orientation of the 

stems. Note that only one departing leaf trace is associated with most stems. Two exceptions are near the 

figure margin in the upper left. Each of these contains one leaf trace that is in an advanced stage of departure and another that is in an earlier stage. This feature indicates that the internodes are fairly long 

in comparison with those of T. grandis. Also note the fact that there are no free petioles in this section, 

a characteristic of the species. Slide USNM 167543b. X 5. 
GEOLOGICAL SURVEY PROFESSIONAL PAPER S74 PLATE 5 

TEMPSKY A ZELLER! ASH AND READ, N. SP. 
PLATE 6 

FIGURES 1-3. Tempskya zelleri Ash and Read, n. sp. (p. 28). 

Slide USNM 167543a, X 10. From USGS fossil plant locality 9702. 

1. Cross section of a stem in which the xylem of the leaf trace is free and the leaf gap in stem has 

closed but the cortex of the stem and leaf trace is still united. Note the typical knoblike bulges at 

the ends of the xylem in the leaf traces in this and the other figures on the plate. Practically all the 

adventitious roots in the figures are cut transversely, indicating that they are vertically oriented, as is 

usual in this species. 

2. Another stem in the false trunk. The xylem of one leaf trace is now free, and a second one is in the 

early stages of departure to the left. 

3. Six stems with leaf traces in various stages of departure. A stem that is in the process of bifurcating is 

in the lower left of the figure. 
GEOLOGICAL SURVEY PROFESSIONAL PAPER 874 PLATE 6 

3 

TEMPSKY A ZELLER! ASH AND READ, N. SP. 
PLATE 7 

Tempskya zelleri Ash and Read, n. sp. (p. 28). 

From USGS fossil plant locality 9702. 

Transverse section of a stem containing two departing leaf traces. One leaf trace at the upper left is in 

an advanced stage of departure, although the associated leaf gap in the stele is still present. A second 

leaf trace which has just begun to form is at the upper right. A leaf gap has formed at the left side of 

the trace, whereas the xylem of the trace and stele are still united at the right. The knoblike bulges at 

the ends of the xylem in the left-hand leaf trace are well developed. Angularity of the stem is particularly 

noticeable in this view. A few of the adventitious roots are randomly oriented, although most are vertically 

oriented as is characteristic of this species. Slide USNM 167543a, X 25. 
GEOLOGICAL SURVEY PROFESSIONAL PAPER 874 PLATE 7 

TEMPSKY A ZELLER! ASH AND READ, N. SP. 
PLATE 8 

FIGURES 1- 3. Tempskya knowltoni Seward, 1924 (p. 4). 

1. General view of part of the false trunk showing several pairs of stems imbedded in a groundmass 

of adventitious roots. Note the absence of free petioles in the section. They are characteristically 

rare in the false trunk of this species as they are in T. zelle1·i n. sp. and T. rossica. The dense, thick 

sclerotic cortex that is typical of T. knowltoni is evident in this figure and the others on the plate. The 

occurrence of just one or two leaf bases with each stem indicates fairly long internodes and contrasts 

with T. grandis where there are often four or more leaf bases with a single stem. Slide USNM 39266 

(section V), X 3. 

2, 3. Cross section of a pair of stems that are in the process of dividing. Note that there is one departing 

leaf trace with each stem and that both have a protuberance marking the beginning of a second 

leaf trace. The excellent preservation of most tissues in ·this fossil is well illustrated in figure 3. 

Both from slide USNM 39266 (secticn V); 2, X 10; 3, X 25. 
GEOLOGICAL SURVEY PROFESSIONAL PAPER 874 PLATE 8 

TEMPSKYA KNOWLTON! SEWARD 
PLATE 9 

FIGURES 1-3. Tempskya minor Read and Brown, 1937 (p. 4). 

1. Part of the false trunk showing the general distribution of the small stems typical of this species imbedded in a groundmass of adventitious roots. The occurrence of only one or two departing leaf traces 

with each stem suggests that the internodes are fairly long and are comparable in length with those 

in T. rossica, T. knowltoni, and T. wyomingensis. Slide USNM 39260c, X 5. 

2. Two sterns in which the xylem cylinder is well preserved. Slide USNM 39·254a, X 10. 

3. Two sterns that are in the process of dividing. Apparently dividing of the stern began at a slightly lower 

level. A departing leaf .trace is present at the upper left of the right-hand stem. The protuberance on 

the side of each stele marks the beginning of a leaf trace. Slide USNM 39260c, X 25. 
GEOLOGICAL SURVEY PROFESSIONAL PAPER 874 PLATE 9 

3 

TEMPSKY A MINOR READ AND BROWN 
PLATE 10 

FIGURES 1-4. Tempskya grandis Read and Brown, 1937 (p. 4). 

1. Transverse section of a stem with three leaf traces in various stages of departure and two leaf-trace 

protuberances. At least one of the traces is free or practically so. Note the comparatively large number of departing leaf traces and leaf-trace protuberances associated with each stem on this plate. This 

demonstrates that the internodes are fairly short in T. grandis, contrasting strongly with T. wesselii and 

T. zelleri which have long internodes and usually only one leaf trace and possibly one leaf-trace protuberance associated with each stem. Slide USNM 39267p, X 3. 

2. A stem with several departing leaf traces and leaf. trace protuberances. Slide USNM 39164b, X 5. 

3. Part of the side of a stem showing the three-layered cortex. The discontinuous and irregular band of sclerenchyma in the inner cortex near the stele is exceptionally well preserved in this specimen, although a 

similar band of sclerotic tissue in the pith is not as clear. Slide USNM 39267i, X 25. 

4. Cross section of a stem which has at least six departing leaf traces. The one on the left edge of the photograph has just become free of the stem, whereas near the center of the photograph the stele of another 

has just separated from the stele of the stem. Near the bottom of the picture an adventitious root is inserted on the stem. Slide USNM 39267j, X 25. 
GEOLOGICAL SURVEY PROFESSIONAL PAPER 874 PLATE 10 

TEMPSKY A GRAN DIS READ AND BROWN 
PLATE 11 

FIGURES 1-4. Tempskya wyomingensis Arnold, 1944 (p. 5). 

All figures are from the holotype (No. 23400) in the Museum of Paleontology, University of Michigan. 

1,2. Two general views of part of the false trunk showing several stems with departing leaf traces and two 

free petioles surrounded by a groundmass of adventitious roots which are mainly vertically oriented. 

Note that two or more departing leaf bases are attached to each stem in these and the other figures 

on the plate, indicating that the nodes are fairly long. X 5. 

3. A rather small stem from which three leaf traces are in the proces·s of departing. This s·ame stem is 

shown in figure 1. X 10. 

4. A somewhat larger stem with twc departing leaf traces and one free petiole that evidently just separated 

from the stem. The outer continuous band of sclerenchyma is clearly visible, but the inner discontinuous 

band is not as clear. The two protuberances above the stele mark the beginning of a leaf trace. X 10. 
GEOLOGICAL SURVEY PROFESSIONAL PAPER 874 PLATE II 

3 

TEMPSKY A WYOMINGENSIS ARNOLD 
PLATE 12 

FIGURES 1-3. Tempskya wesselli Arnold, 1944 (p. 5) . 

All figures are from slides made from the holotype (23399) in the Museum of Paleontology, University of 

Michigan. 

1. A stem from which a leaf trace is in the process of separating. The two continuous bands of sclerenchyma 

separated by a complete band of parenchyma are clearly visible surrounding the stems and the leaf traces 

in all figures on the plate. In the example shown in this figure the leaf gap has closed, the bands of sclerenchyma are still complete, and there is a gap in the parenchymatous layer where the inner band of the 

leaf trace is still fused with the inner band of the stem. Most of the adventitious roots in this figure are 

cut transversely. An exception is the root that is cut more or less tangentially at the lower left. X 25. 

2. General view of a part of the false trunk showing the distribution and remains of four stems in a groundmass of adventitious roots. The stem near the left side of the photograph has been penetrated by several 

roots. The stem near the center is shown in figure 1. X 5. 

3. A stem from which a leaf trace is in the process of separating. In this example the separation has not proceeded quite as far as in figure 1 and a leaf gap is still present. An adventitious root which probably 

arose from the stem is at the lower right imbedded within the band of parenchyma. The root is cut transversely and probably is vertically oriented. A second adventitious root that is in the process of separating 

from the stem is at the lower left. It is cut tangentially and apparently is horizontally oriented. The xylem 

of the root is not connected with the xylem of the stem, but the sclerenchyma bands of the stem cortex 

are connected with the sclerenchymatous cortex of the root. X 10. 
GE:OLOG ICAL SURVE:Y PROFESSIONAL PAPER 87 4 PLATE: 12 

TEMPSKY A WESSELL! ARNOLD 
PLATE 13 

Tempskya superba Arnold, 1958 (p. 5). 

A stem with three leaf bases in various stages of departure. 

Short internodes in this species are responsible for this noteworthy feature of T. superba. The remains of several adventitious roots are visible including one that is in the process of separating from the right side of the 

stem. Although this fossil is not very well preserved, the thick band of parenchyma in the inner cortex and 

the discontinuous, irregular band of sclerenchyma that characteristically surrounds the vascular cylinder in 

this species are visible in a few places, X 10. The figure is from a slide (USNM 167545a) made from the 

holotype (34561) in the Museum of Paleontology, University of Michigan. 
GEOLOGICAL SURVEY PROFESSIONAL PAPER 8,74 PLATE 13 

TEMPSKY A SUPERBA ARNOLD