DEPARTMENT OF THE INTERIOR

UNITED STATES GEOLOGICAL SURVEY

GEORGE OTIS SMITH, DIRECTOR

361

GENOZOIC MAMMAL HORIZONS OF 

WESTERN NORTH AMERICA

BY

HENRY FAIRFIELD OSBORN

WITH

FAUNAL LISTS OF THE TERTIARY MAMMALIA 

OF THE WEST

WILLIAM D1LLER MATTHEW

WASHINGTON

GOVERNMENT PRINTING OFFICE

1909

CONTENTS.

Page.

INTRODUCTION ........................................................... 7

Formations and zones................................................. 7

Life zones........................................................ 7

Geologic formations...........................'..................... 7

'. Correlation................................................................. 8

Bibliography........................................................... 9

CHAPTER I. General geologic and climatic history of the Tertiary............ 19

The Mountain Region................................................. 19

The Plains Region..................................................... 20

Resemblances and contrasts between Mountain and Plains regions........ 21

Resemblances..................................................... 21

Contrasts.......................................................... 21

Geologic history of Mountain basin deposits of the Eocene and Oligocene. 24

Geologic history of the Great Plains deposits of the .Oligocene to lower

Pleistocene.......................................................... 26

Extent............................................................ 26

History of opinion as to mode of deposition.......................... 26

Summary.......................................................... .28

CHAPTER II. Time correlation of mammal-bearing horizons................... 29

The two grand problems............................................... 29

American correlation............................................... 29

American and Eurasiatic correlation................................. 29

Methods of correlation.............'.................................... 30

Bases............................................................. 30

Sources of error.................................................... 30

Preliminary correlation of the Eocene and Oligocene Mountain deposits... 31

Preliminary correlation of the Oligocene to lower Pleistocene Mountain and

Plains deposits...................i.................................. 31

CHAPTER III. Western American Cenozoic horizons......................... 33

Eocene................................................................ 33

I. First faunal phase.............................................. 33

Post-Cretaceous or basal Eocene (e"tage Thane"tien)................ 33

1. Puerco formation; Poiymastodon zone..................... 33

2. Torrejon formation; Pantolambda zone................... 34

II. Second faunal phase............................................ 35

Lower Eocene (6tages Sparnacien, Yprdsien).................... 36

3. Wasatch formation; Coryphodon zone...................... 36

3a. Wasatch of the Bighorn basin .......................... 41

III. Third faunal phase............................................ 42

Lower to middle Eocene (etages Ypr<§sien, Lut^tien infdrieur)..... 43

4. Wind River formation; Lambdotherium and Bathyopsis

zones.................................................... 43

4a. Huerfano formation; Lambdotherium and ? Uintatherium

zones.................................................... 48

3

91406
4 CONTENTS.

CHAPTER III. Western American Cenozoic horizons Continued. ' Page. 

Eocene Continued.

III. Third faunal phase Continued.

Middle Eocene (Stages Lute"tien supe"rieur, Bartonien)........... 50

5. Bridger formation; Orohippus and Uintatherium zones..... 50

Middle to upper Eocene (<§tage Bartonien)...................... 53

Later Eocene deposits of Washakie basin; Uintatherium and 

Eobasileus zones......................................... 53

Upper Eocene (Stages Bartonien in part, Ludien (Ligurien) in 

part)........................................................ 54

7. Later Eocene deposits of Uinta basin; Uintatherium, 

Eobasileus, and Diplacodon zones.......................... 54

Oligocene............................................................. 57

IV. Fourth faunal phase. .^....................................\.... .57

Lower Oligocene, White River group of Hayden (etage Sannoisien 

[Tongrien infe"rieur])........ =................................. 60

8. Chadron formation; Titanotherium zone.................. 60

Middle Oligocene (e"tage Stampien [Tongrien sup6rieur]).......... 62

9. Lower part of Brule clay; Oreodonzone and " Metamynodon 

sandstones".............................................. 62

Upper Oligocene,. first phase................................... 63

10. Upper part of Bfule clay; Leptauchenia zone and "Protoceras sandstones"...................................... 63

Oregon Cenozoic formations................................. 64

R6sum6 of the Oregon deposits as a whole............... 64

John Day formation.................................... 64

Upper Oligocene, second phase................................. 67

11. Middle part of John Day formation; Diceratherium zone 

(also upper part of John Day, transitional)................ 67

Upper Oligocene, latest phase.................................. 68

12. Upper part of John Day formation; Promerycochoerus zone.. 68 

Miocene.............................................................. 70

IV. Fourth faunal phase Continued ............................... 70

Lower Miocene (Stages Aquitanien, Burdigalien)................ 70

13. Arikaree formation; Promerycochoerus zone............... 70

General features......................................... 70

Westerly section....................................... 73

A. Lower division................................. 73

(a) Gering formation........................... 73

(6) Monroe Creek formation............ ....... 73

(c) Harrison formation, Hatcher................. 73

(d) Harrison formation, Agate Spring quarry.... 74

B. Upper division.................................. 74

(e) Upper part of Harrison formation........... 74

Easterly section....................................... 74

A. Lower part of Rosebud.......................... 75

B. Upper part of Rosebud.....:................... 75

V. Fifth faunal phase........ '.'.".................................... 76

Middle Miocene (Stages Helvetien, Sarmatien, Tortonien)........ 76

Faunal changes........................................... 76

14. Deep River sequence; Ticholeptus zone................. 76

Upper Miocene (e"tage Pontien).................................. 79

15. Ogalalla formation (in part); Procamelus zone........... 79
: - CONTENTS. 5

. CHAPTER III. Western American Cenozoic horizons Continued. Page.

 * Miocene Continued.

£! V. Fifth faunal phase Continued.

Last phase of Miocene of first phase 0- Pliocene (6tages Pontien,

Messinien).................................................. 80

\ 16. Ogalalla formation (in part); Peraceras zone............. 80

\ 16a. Rattlesnake formation of John Day Valley, Oregon...... 81

i Pliocene............................................................... 81

' VI. Sixth faunal phase............................................ 82

Middle Pliocene or second phase (e"tage Astien).................. 82

17. Blanco formation; Glyptotherium zone.................... 82

'* Upper Pliocene or lower Pleistocene............................ 83

18. Elephas imperator zone.................................. 83

Pleistocene............................................................ 84

\ VII. Seventh faunal phase.......................................... 84

* Lower Pleistocene (preglacial)................................... 84

^ 19. Equus zone............................................ 85

i Middle Pleistocene (glacial)..................................... 86

/ General characters.......................................... 86

Early phases....................... ...................... 87

I Subsequent phases......................................... 88

> Late phase................................................ 90

i Conclusion. ............................................................. 90

APPENDIX. Faunal lists of the Tertiary Mammalia of the West, by W. D.

? Matthew................................................................ 91

' INDEX. ................................................................... 121
ILLUSTRATIONS.

Page,

PLATE I. Map of the United States, showing general Mountain and Great Plains 

regions, also location of the principal formations, sections, and 

deposits considered in this paper.........."....................... 7

II. Oligocene and Miocene exposures in South Dakota, northwestern

Nebraska, and eastern Wyoming ................................. 60

III. Idealized bird's-eye view of the great Badlands of South Dakota, 

showing channel and overflow deposits in the Oligocene and lower 

Miocene....................................................... 64

FIG. 1. Composite section of the Tertiary deposits of the West................ 23

.2. Map of southwestern Wyoming and northern Utah, showing partial

areas of the Wasatch, Wind River, Bridger, and Uinta formations.... 37

3. Composite columnar section of the Wasatch formation of Bighorn Basin.. 38

4. Columnar section showing the relations of the typical Wasatch section, 

including the Knight formation, to the overlying and underlying 

formations........................................................ 39

5. Columnar section of the Wind River basin, based on the descriptions

of Hayden and Loomis.............................................. 44

6. Columnar section of the Bridger formation, Henrys Fork, western

Wyoming......................................................... 51

7. Preliminary columnar section of the'' Washakie formation,'' Wyoming... 53

8. Columnar section of the Uinta formation, northern Utah............... 55

9. Diagrammatic section of the White River group, South Dakota........ 62

10. Provisional correlation of some of the chief epicontinental OligocenePleistocene deposits and formations of the West in which fossil mammals have been recorded......................................... 65

11. Columnar section of the John Day formation, Oregon.................. 67

12. Columnar section of the Rosebud formation.......................... 70

13. Columnar section of the Gering, Monroe Creek, and Harrison formations,

western Nebraska............................................... 72

14. Diagrammatic section of the Gering, Monroe Creek, and Harrison formations, western Nebraska......................................... 73

15. Diagrammatic section of the Staked Plains (Llano Estacado), Texas, 

showing the relations of the "Clarendon," "Rock Creek," and 

Blanco to the underlying "Panhandle"....:....................... 82

6
U. S. GEOLOGICAL SURVEY BULLETIN NO. 361 PL. I

4!?

MAP OF THE UNITED STATES, SHOWING THE GENERAL MOUNTAIN AND GREAT PLAINS REGIONS; ALSO THE TYPICAL LOCALITIES OF THE PRINCIPAL FORMATIONS,

SECTIONS, AND DEPOSITS CONSIDERED IN THIS PAPER.
KEY TO PLATE I.

PT Puerco, Torrejon, and Wasatch of San Juan

basin, New Mexico ........................... Basal and lower Eocene.

BH Wasatch of Bighorn Basin, Wyoming ............ Lower Eocene.

W Wasatch (typical), Evanston, Wyoming.......... Lower Eocene.

WR Wind River, Wyoming .......................... Lower Eocene. \

H Huerfano, Colorado............................. Lower and middle Eocene. *

B Bridger, Wyoming.....................:........ Middle Eocene.

WK ." Washakie," Wyoming ...-......-..-....---...- Middle and upper Eocene.

U U.inta, Utah ..---.......-.-...----....--......-- Upper Eocene.

12 White River deposits along Swift Current Creek, f 

Assiniboia, Canada........-.....-.-....-..---- Lower Oligocene.

10 White River deposits along Pipestone Creek,

Montana.....-_....,...---.-.--.---.---------- Lower Oligocene.

2 Typical White River and Rosebud, South Dakota.. Oligocene and Miocene. ' 

i White River, Monroe Creek, and Harrison,

Nebraska .-.--.......-.......-..-....-.-..-.- Oligocene and Miocene.

4 Pawnee Buttes section (" Pawnee Creek," " Martin 

Canyon," "Cedar Creek," "Horsetail Creek"), 

Colorado .................................... Oligocene to middle Miocene.

7 John Day, Mascall, and Rattlesnake, Oregon...... Oligocene, Miocene, and Pliocenes

8 " Fort Logan " and Deep River, Montana ......... Lower and middle Miocene.

. M " Flint Creek," Montana. ......................... Middle Miocene.

6 ".Panhandle," "Clarendon," Blanco, and "Rock

Creek," Texas................................ Miocene to Pleistocene. ;

17 " Nebraska" and underlying beds, Nebraska ...... Miocene.

5 "Santa Fe marls," New Mexico .................. Upper Miocene.

9 " Madison Valley," Montana ..................... Upper Miocene.

3 "Republican River," Kansas..................... Lower Pliocene. >

13 "Archer," Florida............................... Lower Pliocene.

14 "Loup River," Nebraska ........................ Upper Pliocene. 

18 Silver Lake, Oregon ............................ Lower Pleistocene.

15 Ash ley River, South Carolina..................... Pleistocene.

16 Port Kennedy, Pennsylvania..................... Middle Pleistocene.

19 Potter Creek cave, California ..................... Middle Pleistocene.

20 Conard fissure, Arkansas......................... Upper Pleistocene.
CENOZOIC MAMMAL HORIZONS OF 

WESTERN NORTH AMERICA.

By HENRY FAIRFIELD OSBORN.

INTRODUCTION.

FORMATIONS AND ZONES.

The main purpose of this paper is faunistic rather than geologic. 

Many of the geologic "groups" and "formations" referred to are 

still imperfectly defined and known, either as to geographic extent or 

as to lithologic content. Many of the geologic terms used are therefore not to -be regarded as final. It should be clearly understood 

also that the geologic sections are largely diagrammatic and in most 

cases are not to be interpreted as giving a clue to the lithologic content.

LIFE ZONES.

It is proposed, according to the ruling of the International Geological Congress and the old practice of invertebrate paleontologists, 

to use the word "zone" for the faunistic levels of such geologic formations or groups as may be synchronized by the presence of certain 

distinctive animals. Thus we may speak of the UintatJierium zone 

of the upper Bridger formation or of the lower "Washakie." The 

word "beds," previously used in the same sense, is liable to cause 

confusion because it is used also for formations.

GEOLOGIC FORMATIONS.

A "formation" has been defined as follows by the United States 

Geological Survey:

In all classes of rocks the cartographic units shall be called formations.

The discrimination of sedimentary formations shall be based upon the local 

sequence of the rocks * * * and the geologist must select for the limitation of 

formations such horizons of change as will best express the geologic development 

and structure of the region and will give to the formations the greatest practical unity 

of constitution. In determining this unity of constitution all available lines of evidence, including paleontology, shall be considered. Each formation shall contain 

between its upper and lower limits either rocks of uniform character or rocks more 

or less uniformly varied in character as, for example, a rapid alternation of shale and 

limestone. * * '* The definition of a formation * * * should include a
8 CEN.OZOIC MAMMAL HORIZONS

statement of the important facts which led to its discrimination and of the characteristics by which it may be identified in the field, whether by geologist or layman.

As uniform conditions of deposition were local as well as temporary, it is to be 

assumed that each formation is limited in horizontal extent. The formation sliould 

be recognized and should be called by the same name as far as it can be traced and 

identified by means of its lithologic character, its stratigraphic association, and its 

contained fossils.

The'Survey has a committee on geologic names, which considers 

all questions of nomenclature that are raised by every paper offered 

for publication. The matter now stands as follows:

1. According to the ruling of the Survey all formations shall receive 

geographic names.

2. The necessity for this rule is demonstrated in the present review, 

because no tvyo formations are found which are altogether coincident 

in time, although they may partly or very largely overlap in time.

3. Both formation and faunistic names are more or less subject to 

the law of priority of definition; but it is considered desirable by the 

committee on geologic names that certain names which are appropriate and have become well established in the literature should be 

retained, although their meanings may be preoccupied technically by 

other names which have not come into such general use.

CORKELATION.

The correlation of the Tertiary mammal horizons of western North 

America with those of Europe has engaged the attention especially 

of Cope (1879, 1884), Scott (1887), Clark (1891, 1896), Dall (1896, 

1897), and Osborn (1897, 1898, 1900). As exact correlation appeared 

to be an essential for the writer's phylogenetic studies of the rhinoceroses and other groups, he published in 1897 a " Trial sheet of the 

typical and homotaxial horizons of Europe" as the basis of cooperation with various European geologists. Their kind criticisms and 

corrections were embodied in a "Second trial sheet" (1898) and in a 

"Third trial sheet" (1900).

In the years 1899 and 1900 the writer gave two addresses a before 

the New York Academy of Sciences, entitled "Correlation between 

Tertiary mammal horizons of Europe and America" and "Faunal 

relations of Europe and America during the Tertiary period and 

theory of the successive invasions of an African fauna into Europe." 

In 1899 Dr. W. D. Matthew published "A provisional classification of 

the fresh-water Tertiary .of the West." 6 In June, 1905, there began 

in the Comptes Rendus a series of papers by Prof. Charles Deperet,

a Osborn, H. F., Correlation between Tertiary mammal horizons of Europe and America; an introduction to the more exact investigation of Tertiary zoogeography; preliminary study, with third trial 

sheet: Ann. New York Acad. Sci., vol. 13, No. 1, July 21,1900, pp'. 1-64.

Osborn, H. F., Correlation des horizons demammiferes tertiaires en Europeeten Amerique: Compt. 

Bend. 8° Cong. geol. intern., 1900, pp. 357-363.

&Bull. Am. Mus. Nat. Hist., vol. 21,1899, pp. 19-75.
OF WESTERN NORTH AMERICA. 9

entitled "L7 evolution des mammiferes tertiaires, methodes et principes, importance des migrations/ ' a covering with fullness and precision the same subject of the Tertiary mammal succession of Europe 

and the migrations between the continents of Eurasia, North America, 

and Africa. For reasons fully set forth in the writer's correlation 

paper of 1899, he has adopted the faunistic subdivisions of France as 

classified by Deperet.

Taking renewed advantage of Professor Deperet's research and 

availing himself of the able cooperation of Doctor Matthew, the 

writer now outlines the methods and data of Tertiary correlation of the 

continental mountain and plains regions, and again treats the subject 

of migrations and American and European parallels from the standpoint of the remarkable .American succession, which is now without 

a gap except in the Pliocene. The Pacific coast and Atlantic coast 

Tertiaries are not included in this review.

Many of the ideas are developments of those first expressed in the 

writer's correlation addresses above referred to and in his other addresses: "Rise of the Mammalia in North America',' (1893),6 and 

"Ten years' progress in mammalian paleontology" (1903).° A 

preliminary abstract of the present paper was published by permission of Director Walcott in March. 1907.d

BIBLIOGRAPHY OF WESTERN CENOZOIC HORIZONS 

AND THEIR CORRELATION.

The following bibliography contains only the most significant 

papers:

RECENT BIBLIOGRAPHY AND FORMATION NAMES.

WEEKS, F. B. Bibliography of North American geology, paleontology, petrology, 

and mineralogy for the years 1892-1900, inclusive. U. S. Geol. Survey, 

Bulls. Nos. 188, 189, 1902.

 North American geologic formation names. Bibliography, synonymy, and 

distribution. U. S. Geol. Survey Bull. No. 191, 1902.

 Bibliography and index of North American geology, paleontology, petrology, 

and mineralogy for the years 1901-1905, inclusive. U. S. Geol. Survey, 

Bull. No. 301, 1906.

GENERAL CORRELATION OF TERTIARY HORIZONS.

CLARK, W. B. Correlation papers Eocene. The Eocene of the United States. 

U. S. Geol. Survey, Bull. No.'83, 1891, pp. 9-159.

Eocene of the Atlantic coast, Gulf States, Pacific coast; historical sketch of the Eocene 

of the interior. Table showing relative position of interior Eocene deposits. Map. 

Extensive bibliography.

oL'evolutioji des mammiferes tertiaires. [1] Methodes et principes: Compt. Rend. Acad. Sci. Paris, 

vol. 140 (June 5,1905), p. 1517. [2J Reponse aux observations de M. Boule: Idem, vol. 141 (July 3,1905), 

p. 22. [3] Importance des migrations: Idem, vol. 141 (Nov. 6,1905), p. 703. [4] Importance des migrations: Idem, vol. 142 (Mar. 12, 1906), p. 618.

6 Proc. Am. Assoc. Adv. Sci., 1894, pp. 188-277. Am. Jour. Sci., 3d ser., vol. 46,1893, pp. 379-392, 448-446.

cCompt. Rend. 6e Gong, intern, de zoologie, 1904, pp. 86-113.

<J Tertiary mammal horizons of North America: Bull. Am. Mus. Nat. Hist., vol. 23, art. 11, March 30, 

1907, pp. 237-253. I
10 CENOZOIC MAMMAL HORIZONS

COPE, E. D. The relations of the horizons of extinct Vertebrata of Europe and North 

America. U. S. Geol. andGeog. Survey Terr., Bull., vol. 5, No. 1,1879.

Correlation of Mesozoic and Cenozoic horizons of Europe and North America.

 The Vertebrata of the Tertiary formations of the West. Kept. U. S. Geol. 

Survey Terr., vol. 3, 1883 (1884). Section I. The Tertiary formations 

of the central region of the United States. Section II. The horizontal 

relations of the North American Tertiaries with those of Europe.

BALL, W. H. A table of the North American Tertiary horizons correlated with one 

another and with those of western Europe; with annotations. U. S. 

Geol. .Survey, 18th Ann. Kept., 1896-97, pt. 2, 1898.

Marine Tertiary horizons of the Atlantic coast and of the Gull States correlated 

with one another, with those of the Western States and those of western Europe.

DAWKINS, W. BOYD. The classification of the Tertiary period -by means of the 

Mammalia. Quart. Jour. Geol. Soc., 1880, pp. 379-405.

Tertiary and Quaternary horizons and faunae of Great Britain, France, and Italy 

. correlated.

FILHOL, H. Observations sur le ine'rnoire de M. Cope intitule" Relations des horizons * * * d'animaux verte'bre's fossiles en Europe et en Ame'rique. 

Ann. sci. geol., vol. 17, art. 5, 1885, pp. 1-18,

MARSH, 0. C. Geologic horizons as determined by vertebrate fossils. Am. Jour. 

Sci., Oct., 1891, 3d ser., vol. 42, pp. 336-338.

 Comparative value of different kinds of fossils in determining geological age. 

Am. Jour. Sci., Dec., 1898, 4th ser., vol. 6, pp. 483-486. 

Value of a form depends upon its modifiability in accordance with changing conditions.

OSBORN, H. F. Correlation between Tertiary mammal horizons of Europe and 

America; an introduction to the more exact investigation of Tertiary 

zoogeography; preliminary study, with third trial sheet. New York 

Acad. Sci., Ann., vol. 13, 1900, pp. 1-64.

 Correlation des horizons de mammiferes tertiaires en Europe et en Ame'rique. 

Compt. Rend. 8e Cong. g6ol. intern., 1900, pp. 357-363.

 The geological and faunal relations of Europe and America during the 

Tertiary period and the theory of the successive invasions of an African 

fauna. Science, n. s., vol. 2, 1900, pp. 561-574. 

Popular presentation of above-cited address.

GENERAL GEOLOGY AND FAUNAE (NORTH AMERICA).

DA vis, W. M. The fresh-water Tertiary formations of the Rocky Mountain region. 

Am. Acad. Arts and Sci., Proc., vol. 35, 1900, pp. 346-373.

History of opinion on mode of formation; evidence against lake-bed hypothesis 

and in favor of fluviatile origin.

GILBERT, G. K. The underground waters of the Arkansas Valley in eastern Colorado. 

U. S. Geol. Survey, 17th Ann. Kept., pt. 2, 1896, pp. 553-601. 

Rocky Mountain deposits may be of fluviatile and not of lacustrine origin.

JOHNSON, W. D. The High Plains and their utilization. U. S. Geol. Survey, 21st 

Ann. Rept., pt. 4, 1901, pp. 601-741; 22d Ann. Rept., pt. 4, 1902, pp. 

631-669. 

Tertiary deposits of the plains, of fluviatile and flood-plain origin.

MARSH, 0. C. Ancient lake basins of the Rocky Mountain region. Am. Jour. Sci., 

Ja-n., 1875, 3d ser., vol. 9, pp. 49-52.

 Introduction and succession of vertebrate life in America. Am. Jour. Sci., 

3d ser., vol. 9, 1877, pp. 337-378. 

Plate showing successive horizons named from characteristic genera.
OF WESTERN NORTH AMERICA. ' 11

MATTHEW, W. D. A provisional classification of the fresh-water Tertiary of the West. 

Am. Mus. Nat. Hist., Bull., vol. 12, 1899, pp. 19-77.

Divisions of the Tertiary lake basins; fossiliferous horizons of the Great Plains; extensive faunal lists.

OSBORN, H. F. Ten years' progress in the mammalian paleontology of North America. 

Compt. Rend. 6° Gong, intern, de zoologie, session de Berne, 1904, 

pp. 86-113. Reprinted without the plates in Am. Geologist, vol. 36, 

1905, pp. 199-229.

A summary. New phylogenetic problems. Review of the successive faunso. Extensive references.

WORTMAN, J. L. Studies of Eocene Mammalia in the Marsh collection, Peabody 

Museum. Pt. II, Primates. Am. Jour. Sci., June, 1903, vol. 15, pp. 

419-436. '

European and American early Tertiary faunfe and Horse, probably derived from temperate Arctic land mass.

EOCENE.

COPE, E. D. The badlands of .Wind River and their fauna. Am. Naturalist, vol. 14,

1880, pp. 745-748. 

Eocene.

DARTON, N. H. Geology of the Bighorn Mountains. U. S. Geol. Survey, Prof. Paper 

No. 51, 1906. 

See especially Bridger [i. e.. Wind Rivur] formation, p. 70.

DotroLASS, EARL. The discovery of Torrejon mammals in Montana. Science, n. s., 

vol. 15, 1902, pp. 272-273.

 A Cretaceous and lower Tertiary section in south-central Montana. Am. 

Philos. Soc., Proc., vol. 41, 1902, pp. 207-224.

Sketch of the Jurassic and Cretaceous deposits. Probable relations of the Laramie 

and overlying beds. Fossil mammals of the Fort Union1 beds.

EARLE, CHARLES. See OSBORN, H. F., and EARLE, CHARLES. 

HAY, 0. P. The fossil turtles of the Bridger basin. Am. Geologist, vol. 35, June, 

1905, pp. 327-342. 

Evidence showing that the Bridger basin Is of flood-plain, not lacustrine origin.

HILLS, R. C. Recently discovered Tertiary beds of the Huerfano basin, Denver, 1888.

 Additional notes on the Huerfano beds. Colorado Sci. Soc., Proc., Oct. 7, 

1889.

 Remarks on the classification of the Huerfano Eocene. Colorado Sci. Soc.,

Proc., vol. 4, 1891, pp. 7-9. 

HAYDEN, F. V. Geological report of the exploration of the Yellowstone and Missouri

rivers, by F. V. Hayden, assistant to Col. William F. Raynolds, U. S.

Engineers, Washington, 1869.

 Preliminary field report of the United States Geological Survey of Colorado 

and New Mexico (separate), Washington, 1869. 

Bridger group, type description, p. 91.

LOOMIS, F. B. Origin of the Wasatch deposits. Am. Jour. Sci., May, 1907 4th ser., 

vol. 23, pp. 356-364.

Analysis of the fauna, of the stratigraphy, and of the petrography disproves lake-bed 

hypothesis and supports flood-plain hypothesis of the origin of the deposits. Detailed 

section. Lambdotherium primxvum sp. nov., Qlyptosaurus obtusidens sp. nov.

MATTHEW, W. D. A revision Of the Puerco fauna. Am. Mus. Nat. Hist., Bull., vol. 

9, 1897, pp. 259-323. 

Faunal distinctlveness of the Puerco and Torrejon.
12 CENOZOIC MAMMAL HORIZONS

MCMASTER, J. B. Stratigrapliical report upon the Bridger beds in the Washakie basin, 

Wyoming Territory, accompanied by profiles of three sections. In 

Osborn, H. F., A memoir upon Loxolophodon and Uintatherium . . . 

E. M. Mus. Geol. Archseol. Princeton, etc., Contr., 4°, vol. 1, No. 1, 

1881. 

Washakie formation.

OSBORN, H. F. A memoir upon Loxolophodon and Uintatherium. E. M. Mus. Geol. 

Archajol. Princeton, etc., Contr., vol. 1, No. 1, 1881. 

'' Washakie" more recent than Bridger formation.

 The Perissodactyla. Part III of Scott, W. B., and Osborn, H. F., The 

Mammalia of the Uinta formation. Am. Philos. Soc., Trans., n. s., 

vol. 16, pt. 3, Aug. 20, 1889, pp. 505-530.

 Fossil mammals of the Uinta Basin; Expedition of 1894. Am. Mus. Nat. 

Hist., Bull., vol. 7, 1895, pp. 71-105.

Geology of the Uinta Basin; the three fauiial levels (horizons A, B, C), with faunal 

lists. New genera and species, especially of Mesonyx, Telmatherium, Sphenoccslus, and 

Elotherium.

 The Huerfano lake basin, southern Colorado, and its Wind River and Bridger 

fauna. Am. Mus. Nat. Hist., Bull., vol. 9, 1897, pp. 247-258.

Stratigraphy; analysis of Hill's report; faunal division into a lower horizon of Wind' 

River age and an upper horizon of Bridger age.

 and EARLE, CHARLES. Fossil mammals of the Puerco beds; collection of 1892. 

Am. Mus. Nat. Hist., Bull., vol. 7, 1895, pp. 1-70. 

Notes on the geology (Wortman). Analysis and description of the fauna.

 and WORTMAN, J. L. Fossil mammals of the Wahsatch and Wind River beds; 

collection of 1891. Am. Mus. Nat. Hist., Bull., vol. 4, 1892, pp. 81-147

Geology of the Bighorn Basin (Wortman), p. 135; analysis and description of the 

fauna (Osborn).

SCOTT, W. B. The upper Eocene lacustrine formations of the West. Am. Assoc. 

Adv. Sci., Proc., 1887 (1888), p. 217. Abstract.

 The upper Eocene lacustrine formations of the United States. Am. Assoc. 

Adv. Sci., Proc., vol. 36, 1887, pp. 217-218.

 The geological and faunal relations of the Uinta formation. Pt. I of Scott,

W. B., and Osborn, H. F., The Mammalia of the Uinta formation. Am. 

Philos. Soc., Trans., n. s.. vol. 16, pt. 2, Aug. 20, 1889, pp. 462-470.

 The selenodont artiodactyls of the Uinta Eocene. Wagner Free Inst. Sci., 

Trans., vol. 6, 1899, pp. i-xiii, 15-122, pis. 1-4.

Angular unconformity between horizons B and C. White River beds homotaxial with 

Ronzon ot France (vide Hatcher). Uinta compared with Paris gypsum (Lutetien), i e. 

lower Oligocene [upper EoceneJ.

SINCLAIR, W. J. Volcanic ash in the Bridger beds of Wyoming. Am. Mus. Nat. 

Hist.,.Bull. 22, 1906, pp. 273-280.

General features of the geology. Lithologic and stratigraphic classification of the 

Bridger group.

VEATCH, A. C. Geography and geology of a portion of southwestern Wyoming, with 

special reference to coal and oil. U. S. Geol. Survey, Prof. Paper No. 

56, 1907.

Deposits of the period between the known Cretaceous and the known Eocene; Evanston formation (Eocene?), p. 80; Wasatch group, pp. 87-96; Green River formation, 

p. 97; Bridger formation, p. 99.
OF WESTERN NORTH AMERICA. 13

WORTMAN, J. L. Geological and geographical sketch of the Bighorn Basin. In 

Osborn, H. F., and Wortman, J. L., Fossil mammals of the Wahsatch 

and Wind River beds. Am. Mus. Nat. Hist., Bull., vol. 4, 1892, pp. 

135-144. 

Wind River beds distinct from and successive to the Wasatch of Bighorn Basin.

 and OSBORN, H. F. See OSBORN, H. F., and WORTMAN, J. L. 

OLIGOCENE, MIOCENE, PLIOCENE.

COCKERELL, T. D. A. The fossil fauna and flora of the Florissant (Colorado) shales. 

Univ. Colorado, Studies, vol. 3, 1906, Boulder, Colo., pp. (157-176. 

Birds, fishes, insects, mollusks, plants.

COPE, E. D. Observations on the faunte of the Miocene Tertiaries of Oregon. U. S. 

Geol. and Geog. Survey Terr., Bull., vol. 5, 1879-80, pp. 55-69. 

John Day (Oligocene).

 Second contribution to a knowledge of the Miocene fauna of Oregon. Am. 

Philos. Soc., Proc., vol. 18, 1879, pp. 370-376. 

John Day (Oligocene).

 The White River beds of Swift Current River, Northwest Territory.' Am. 

Naturalist, vol. 19, 1885, p. 163. 

Oligocene, White River.

 The Vertebrata of the Swift Current Creek region of the Cypress Hills. Geol. 

and Nat. Hist. Survey Canada, Ann. Rept., vol. 1, 1885 (1886), appendix to Article C, pp. 79-85. 

Oligocene.

 A preliminary report on the vertebrate paleontology of the Llano Estacado. 

Geol. Survey Texas, 4th Ann. Rept., 1892 (1893), pp. 1-136.

Description of the vertebrate fauna of the Loup Fork beds of the Llano Estacado, 

Texas.

CUMMINS, W. F. Notes on the geology of northwest Texas. Geol. Survey Texas, 3d 

Ann. Rept., 1891 (1892), pp. 129-200; 4th Ann. Rept., 1892 (1893), pp. 

179-238. 

Geology of the Llano Estacado.

DAIA, W. H. Age of the Peace Creek bone beds of Florida. Acad. Nat. Sci. Philadelphia, Proc., 1891, p. 121. 

Included in Pliocene.

 Geological results of the study of the Tertiary fauna of Florida, 1886-1903. 

Wagner Free Inst. of Science, Philadelphia, Trans., vol. 3, pt. 6, 1903, 

pp. 1541-1620. 

Oligocene and later formations. Tertiary Mollusca.

 and HARRIS, G. D. Correlation papers. The Neocene of North America. 

U. S. Geol. Survey, Bull. No. 84, 1892.

See especially Chapter V1, on the supposed Neocene of the interior region, considered 

by States, pp. 280-317. Table showing the vertical range of the Neocene of the interior. Map, p. 178. List 01 names applied to Cenozoic beds and formations ol the United 

States, p. 320.

DARTON, N. H. Preliminary report on the geology and underground-water resources 

of the central Great Plains. U. S. Geol. Survey, Prof. Paper No. 32, 

Washington, 1905.

See especially Chadron ( Titanotherium), Brule (Oreodon), Arikaree, Ogalalla formations.
14 CENOZOIC MAMMAL HORIZONS

DARTON, N. H. Age of the Monument Creek formation. Am. Jour. Sci., Sept., 1905, 

4th ser., vol. 20, pp. 178-180. 

Titanotherium remains. Oligocene.

 Geology and underground waters of the Arkansas Valley in eastern Colorado, 

U. S. Geol. Survey, Prof. Paper No. 52, 1906.

. Monument Creek formation, containing Titanotherium of White River age, p. 34; 

Nussbaum formation, of late Tertiary age, p. 34.

DOUGLASS, EARL. The Neocene lake beds of western Montana, and descriptions of 

some new vertebrates from the Loup Fork. Univ. Montana, thesis, 

June, 1899.

Geology, faunae, and correlation of White River, Deep River, and Madison 'Valley; 

Loup Fork horizons in Montana; systematic .description of certain fossil camels, etc.

 Fossil Mammalia of the White River beds of Montana. Am. Philos. Soc., 

Trans., n. s., vol. 20, 1901, pp. 1-42, pi. ix.

Pipestone beds, Toston beds, Blacktail Deer Creek beds. Geology and faunae; new 

genera and species of mammals.

 New vertebrates from the Montana Tertiary. Carnegie Mus. (Pittsburg, 

Pa.), Ann., vol. 2, No. 2, 1903, pp. 145-200.

Sage Creek beds (?Eocene), White River deposits, Fort Logan beds (upper Oligocene), Deep River and Flint Creek beds. New mammals described.

 The Tertiary of Montana. Carnegie Mus. (Pittsburg, Pa.), Mem., vol. 2, 

1905, pp. 203-224. 

Chiefly a description of Mops, Xenotherium, and other lower White River mammals.

GIDLEY, J. W. The fresh-water Tertiary of northwestern Texas, American Museum 

Expedition of 1899-1901. Am. Mus. Nat. Hist.; Bull., vol. 19, 1903, 

pp. 617-635.

Geologic notes and sections; new mammals described. Rock Creek beds = Sheridan (Equus) beds (Pleistocene); Blanco beds (Pliocene); sections (1) at Mount Blanco 

of (?) Goodnight (Paloduro) Miocene, (2) showing Panhandle (lower or middle Miocene) 

beds, and (3) of Clarendon (Loup Fork) and Patihandle. Maps, faunae.

 See MATTHEW, W. D., and GIDLEY, J. W.

GILBERT, G. K. Lake Bonneville. U. S. Geol. Survey, Mon., vol. 1, 1890.

The age of the Equus fauna, p. 393. Faunally later than upper Pliocene of Arno 

Valley, and earlier than mid-Pleistocene, but surviving in Lake Bonneville region into

middle or upper Pleistocene. 

HARRIS, G. D. See DALL, W. H., and HARRIS, G. D.

HATCHER, J. B. Discovery of Diceratherium, the two-horned rhinoceros, in the White 

River beds of South Dakota. Am. Geologist, vol. 13, 1894, pp. 360-361. 

Top of White River correlated with John Day formation.

 On a small collection of vertebrate fossils from the Loup Fork beds of northwestern Nebraska; with note on the geology of the region. Am. Naturalist, vol. 28, 1894, pp. 236-248. 

JElurodon, ApJielops, Teleoceras; Loup Fork and Equus beds.

 The Titanotherium beds. Am. Naturalist, Mar. 1, 1893, pp. 204-221.

Geographic distribution, description, stratigraphy; faunistic division into lower, 

middle, and upper beds.

 r- Origin of the Oligocene and Miocene deposits of the Great Plains. Am. 

Philos. Soc., Proc., vol. 41, 1902, pp. 113-131.

Gering, Arikaree, Ogalalla, Monroe Creek, Harrison, and Nebraska of Scott; classification of the Oligocene and Miocene; "lake-bed" hypothesis of origin disproved in 

favor of fluviatile, flood-plain, andeolian hypothesis.
/

' OF WESTERN NORTH AMERICA. 15

f

^ HAWORTH, E. Physical properties of the Tertiary [of Kansas]. Univ. Geol. Survey

^ Kansas, vol. 2, 1896, pp. 247-281.

j Rejects '' lake-basin'' hypothesis in favor of hypothesis of fluviatile origin of Tertiary 

r of Kansas.

la HAY, R. Northwest Kansas; its topography, geology, climate, and resources. Kan-

> » sas State Bd. Agr., 6th Bien. Kept., 1889.

V See especially discussions of the Tertiary geology of Kansas.

IRVING, J. D. The stratigraphical relations of the Browns Park beds of Utah. New 

i; York Acad. Sci., Trans., vol. 15, Sept., 1896, p. 252. 

The beds in Browns Park Valley assigned to the Pliocene.

KNOWLTON, F. H. Fossil flora of the John Day basin, Oregon. U. S. Geol. Survey, 

i| . Bull. No. 204, 1902. 

\y> Geology, pp. 14-20, 102-108. Mascall formation referred to upper Miocene.

.* LEIDY, J., and LUCAS, F. A. Fossil vertebrates from the Alachua clays of Florida. 

$ Wagner Free Inst. Sci., Trans., vol. 4, 1896, pp. vii-otiv, 15-61.

i Mastodon ftoridanus,Aphelopsfossiger,A. malacorhinus, Procamelus major, P. medius, 

I, P. minimus, Hippotherium plicatile, H. gratium, Equus major.

LOOMIS, F. B. Two new river reptiles from the titanothere beds. Am. Jour. Sci., 

& Dec., 1904, 4th ser., vol. 18, pp. 427-432.

I Flood-plain origin of Titanotherium beds.

||' LUCAS, F. A. See LEIDY, J., and LUCAS, F. A. 

r MATTHEW, W. D. Is the White River Tertiary an eolian formation? Am. Naturalist,

 ft vol. 33, 1899, pp. 403-408.

£ Summary of the paleontologic evidence against the lake-basin hypothesis.

II Fossil mammals of the Tertiary of northeastern Colorado. Am. Mus. Nat. 

i Hist., Mem. 1, pt. 7, Nov., 1901.

\\l Stratigraphy of White.River formation (Horsetail Creek, Cedar Creek, and Martin 

t,l Canyon beds); of Loup Fork formation (Pawnee Creek beds). Evidence as to mode 

!] of deposition (chieQy eolian); analysis of fauna?; correlation of horizons; systematic 

descriptions.

';; The fauna of the Titanotherium beds at Pipestone Springs, Mont. Am.

^ Mus. Nat. Hist., Bull., vol. 19, 1903, pp. 197-226.

' Notes on stratigraphy; systematic descriptions of new fossil mammals.

^ A lower Miocene fauna from South Dakota. Am. Mus. Nat. Hist., Bull.,

if) vol. 23, 1907, 169-219.

* Lower and upper Rosebud formations and fauna;; comparison with American Oligo-

'( cene and Miocene faunas, New Carnivora, Rodentia. Artiodactyla.

,''! and GIDLEY, J. W. New or little-known mammals from the Miocene of South. 

| Dakota. Am. Mus. Nat. Hist., Bull., vol. 20, 1904, pp. 241-271.

^ Upper Miocene Loup Fork beds, geology and launal list; lower Miocene Rosebud 

f beds (new name) New Carnivora and Rodentia

'* MERRIAM, J. C. A contribution to the geology o'f the John.Day basin. Univ. Cali- 

;>'') fornia, Bull. Dept. Geology, vol. 2, 1901, p. 269.

Geology, fauna;, and flora; of the Cretaceous (Chico and Knoxville), Eocene (Clarno), 

Oligocene (John Day series), Columbia lava, Miocene (Mascall), Pliocene (Rattlesnake), 

U Quaternary.

I; Carnivora from the Tertiary formations of the John Day region. Univ. Cali- 

^ foruia, Bull. Dept. Geology, vol. 5, 1906, pp. 1-64, pis. 1-6.

[: Brief notes on the Tertiary formations of the John Day region. Description of the

'* Canidas and Felidas. John Day carnivores more advanced in structure than White

'\ River carnivores, less advanced than Loup Fork carnivores.

. !v 

'*
16 CENOZOIC MAMMAL HORIZONS

[OsBORN, H. F.] Professor Fraas on the aqueous vs. eolian deposition of the White 

River Oligocene of South Dakota. Science, n. s., vol. 14, 1901, pp. 

210-212.

Tilanolherium beds formed by river and flood-plain deposits exposed during dry 

season. Middle Oreodon beds deposited by a shallow lake with dissolved materials of 

varying concentration (cf. banded layers). Upper Oreodon beds formed by eolian loess.

OSBORN, H. F. See SCOTT, W. B., and OSBORN, H. F.

 and WORTMAN, J. L. Perissodactyls of the lower Miocene White River beds. 

Am. Mus. Nat. Hist., Bull., vol. 7, 1893, pp. 343-375. 

Oligocene.

 Fossil mammals of the lower Miocene White River beds; collection of

1892. Am. Mus. Nat. Hist., Bull, vol. 6, 1894, pp. 199-228. 

Succession of species in the White River "Miocene" [<= Oligocene].

PETERSON, 0. A. Osteology of Oxydactylus. A new genus of camels from the Loup 

Fork of Nebraska, with descriptions of two new species. Carnegie Mus., 

Ann., vol. 2, No. 3, Feb., 1904.

Geologic notes and section, pp. 473-475.

 Description of new rodents and discussion of the origin of Dxmonelix. Carnegie Mus., Mem., vol. 2, 1905, pp. 139-191.

New rodents from the Dxmonelix beds, Harrison formation (Miocene). Dxmonelix 

explained as the cast of a spiral burrow made by rodents (Stencofiber).

 The Agate Spring fossil quarry. Carnegie Mus., Ann., vol. 3, No. 4, 1906, 

pp. 487-494. 

Horizon regarded as equivalent to the top of the lower Harrison formation.

 The Miocene beds of western Nebraska and eastern AVyoining and their vertebrate faunae.

Carnegie Mus., Ann., vol. 4, No. 1,1900, pp. 21-72.

 Newsuilline remains from the Miocene of Nebraska. Carnegie Mus., Ann., 

vol. 2, No. 8, 1906, pp. 305-320.

N. sp. in Thinohyus. Comparison with John Day species shows greater specialization, p. 320.

SCOTT, W. B. The mammals of the Deep River beds. Am. Naturalist, vol. 27/1893, 

pp. 659-662.

Preliminary description

 The later Tertiary lacustrine formations of the West. Geol. Soc. America, 

Bull., vol. 5, 1893 (1894), pp. 594-595. 

Nebraska formation, Cosoryx beds. Type reference.

 The Mammalia of the Deep River beds. Am. Philos. Soc., Trans., n. s., vol. 

18, 1895, No. 2, pp. 55-185. 

Geology, pp. 55-63. European homotaxis with Sanson and Simorre (middle Miocene).

 and OSBORN, H. F. Preliminary account of the fossil mammals from the 

White River formation contained in the Museum of Comparative Zoology. 

Mus. Comp. Zool. Harvard Coll., Bull., vol. 13, 1887, pp. 152-171.

SCUDDER, S. H. The Tertiary insects of North America. U. S. Geol. Survey Terr., 

Rept., vol. 13, 1890.

Map of the Tertiary lake basin at Florissant, Colo. Geology of the deposits yielding 

Tertiary insects in America. Florissant^ Amyzon beds (Oligocene?). Volcanic origin 

of the deposits.
OF WESTERN NORTH AMERICA. 17

SINCLAIR, W. J. New or imperfectly known rodents and ungulates from the John 

Day series. Univ. California, Bull. Dept. Geology, vol. 4, 1905, pp. 

125-143. 

STERNBERG, C. H. The Loup Fork Miocene of western Kansas. Kansas Acad. Sci., 

Trans., vol. 20, pt. 1, 1904, pp. 71-74.

Mode of deposition discussed.

WORTH AN, J. L. On the divisions of the White River or lower Miocene of Dakota. 

Am. Mus. Nat. Hist., Bull., vol. 5, 1893, pp. 95-106.

Description and stratigraphic table of the Titanotherium and Oreodon beds; Proto- 

' ceras beds; faunal distribution and succession oyypes.

. See OSBORN, H. F., and WORTMAN, J. L.

PLEISTOCENE.

BEEDE, J. W. See HAWORTH, E., and BEEDE, J. W.

COPE, E. D. Description of some vertebrate remains from the Port Kennedy bone

deposit. Acad. Nat. Sci. Philadelphia, Proc., vol. 11, 1876,' pt. 2,

pp. 193-267. 

Pleistocene.

 The Silver Lake of Oregon and its region. Am. Naturalist, vol. 23, 1889, 

pp. 970-982. 

Pleistocene. Fauna and geology.

: and WORTMAN, J. L. An account of the mammalian fauna of the post-Plio- 

" cene deposits of Indiana. State Geol. Indiana, 14th Kept., pt. 2, 1884. 

Pleistocene.

 FURLONG, E. L. An account of the preliminary excavations in a recently explored

 i Quaternary cave in Shasta County, Cal. Science, n. a., vol. 20, July 8, 

1904, pp. 53-54. 

Faunal lists.

 The exploration of Samwel Cave. Am. Jour. Sci., September, 1906, 4th ser.,

' vol. 22, pp. 235-247.

 Pleistocene.

\ ' Reconnoissance of a recently discovered Quaternary cave deposit near

Auburn, Cal. Science, n. s., vol. 25, 1907, pp. 392-394. ( ? ^. Faunal lists.

GILBERT, G. K. See HALL, J., and GILBERT, G. K.

HALL, J., and GILBERT, G. K. Notes and observations on the Cohoes mastodon. Notes 

of investigations at Cohoes with reference to the circumstances of the deposition of the skeleton of Mastodon. New York State Cab. Nat. Hist, 21st 

Ann. Rept., 1871. 

Characteristic sections of Pleistocene deposits.

HATCHER, J. B. Discovery of a musk-ox skull (Ovibos cavifrons Leidy) in West Virginia, near Steubenville, Ohio [by Sam Huston]. Science, vol. 16,1902, 

p. 707. 

Faunal changes in the region during glacial period.

HAWORTH, E., and BEEDE, J. W. The McPherson Equus beds [of Kansas]. Univ.

Geol. Survey Kansas, vol. 2, 1896 (1897), pp. 287-296. 

MATTHEW, W. D. List of the Pleistocene fauna from Hay Springs, Nebr. Am. Mus.

Nat. Hist., Bull, vol. 16, 1902, pp. 317-322.

Hay Springs (Nebraska), Silver Lake (Oregon), Oregon Desert, Washtuckna Lake 

(Washington).

56092 Bull. 361 09 2
18 CENOZOIC MAMMAL HORIZONS OF WESTERN NORTH AMERICA.

MERCER, H. 0. The bone cave at Port Kennedy, Pa. Acad. Nat. Sci. Philadelphia, Jour., vol. 11, 1899, pt. 2.

Referred to the Pleistocene, but without comparison with other cave formations and 

faunsc.

MERRIAM, J. C. Recent cave exploration in California. Ani. Anthropologist, n. s., 

vol. 8, 1906, pp. 221-228. 

Mercer's, Potter Creek, Samwel, and Stone Man caves, probably of Quaternary age.

SCUDDER, S. H. The effect of glaciation and of the glacial period on the present

fauna of North America. Am. Jour. Sci., Sept., 1904, 3d ser., vol. 48,

pp. 179-187. 

SHUFELDT, R. W. A study of the fossil avifauna of the Equus beds of the Oregon

desert. Acad. Nat. Sci. Philadelphia, Jour., vol. 9, 1892, p. 389. 

SINCLAIR, W. J. A preliminary account of the exploration of the Potter Creek cave,

Shasta County, Cal. Science, n. s., vol. 17, 1903, pp. 708-712.

 The exploration of the .Potter Creek cave. Univ. California, American 

Archaeology and Ethnology, vol. 2, 1904, pp. 1-27. pis. 1-14. 

Late Quaternary age.

 New Mammalia from the Quaternary caves of California. Univ. California,

Bull. Dept. Geology, vol. 4, 1905, pp. 145-161. 

WILLISTON, S. W. An arrowhead found with bones of Bison occidentalis in western

Kansas.. Am. Geologist, vol. 30, 1902, pp. 313-315.

Arrowhead in undoubted association with an extinct species, Bison occidentalis, in 

beds referred by Williston to the Equus beds.

 The Pleistocene [of Kansas]. Univ. Geol. Survey Kansas, vol. 2, 1896, pp. 

299-308. 

Kansas Pleistocene deposits and fauna;. «.

WORTMAN, J. L. See COPE, E. D., and WORTMAN, J. L.
, CHAPTER I.

GENERAL GEOLOGIC AND CLIMATIC HISTORY OF THE

TERTIARY.

Although, as observed in the introduction (p. 7), we still lack 

exact knowledge, certain broad generalizations are beginning to 

emerge from the facts collected chiefly by American paleontologists 

since the pioneer studies of Hayden and Leidy in the middle of the 

last century.

Among the earlier contributors to our geologic and stratigraphic

knowledge are Hayden, Leidy, Marsh, Cope, King, Scott, and Osborn. 

Among the more recent contributors are Matthew, Hatcher, Wortman, Darton, Merriam, Peterson, Douglass, Gidley, Granger, and 

Sinclair."

The most central fact established is that there were during the 

Tertiary period two grand natural divisions of geologic deposition 

and of animal and plant habitat, similar to the two natural divisions 

which exist to-day, namely, (1) the Mountain Region and (2) the 

Plains Region.

THE MOUNTAIN REGION.

The mountain and high-plateau region, as a whole, stretched 

north through British Columbia to its broad Asiatic land connection, 

which was apparently interrupted and renewed more than once during the Tertiary period. On the south it terminated, according to 

Suess, in the mountains which form the northern boundary of the 

southern Mexican State of Oaxaca. We have a few glimpses of the 

life of limited areas of this vast region in Tertiary time.

The Eocene Tertiaries of the Mountain Region, lying in and west 

of the Rockies, in which the life is best known, were partly formed 

by the post-Cretaceous or post-Laramie uplift, accompanied by 

great volcanic activity, lava flows, and eruptions of volcanic dust, 

and by the formation of a series of lake, river, and flood-plain basins, 

filled with volcanic and erosion sediments.

a Six of these observers either have been continuously or were for a time connected with the expeditions sent out by the present writer from the department of vertebrate paleontology of the Amer'can 

Museum of Natural History, with instructions to combine very precise geologic and paleontologic 

observations. Of the others, Hatcher's pioneer work for the United States Geological Survey and 

for the Carnegie Museum, Merriam's and Sinclair's work in the John Day region (University of California studies), and Douglass's observations in Montana have been most important. Darton's report 

on the central Great Plains (1905) is the latest and most comprehensive contribution.
20 CENOZOIC MAMMA.L HORIZONS

The mammalian life of this region from New Mexico on the south 

to Montana on the north is fully known from the beginning to the 

close of the Eocene epoch, while it is imperfectly known during the 

Miocene and Pliocene epochs. It shows four phases in its relations 

to Europe.

1. Throughout the lower Eocene epoch it is closely similar to the 

far-distant life of western Europe. (See first and second faunal 

phases, pp. 33, 35-36.)

2. There follows a middle and upper Eocene interval of faunal separation from Europe. (See third faunal phase, pp. 42-43.)

3. Again there is a faunal reunion, near the beginning of the Oligocene epoch; then a divergence, less marked than before; then a 

reunion in the middle Miocene, and another in the Pleistocene. But 

from the Oligocene onward western America, northern Asia, and 

Europe, or Eurasia, form a single great zoologic province until 

the late Pleistocene. (See fourth, fifth, and sixth faunal phases, 

pp. 57-60, 76, 82.)

4. Finally, the present epoch is one of faunal divergence or separation. (See seventh faunal phase, p. 84.)

THE PLAINS REGION.

The Tertiaries of the Plains Region lie east of the Rockies from 

Montana southward.

During the entire Eocene epoch the country stretching to the 

Mississippi and eastward to the Appalachians and Atlantic coast is, 

with a few exceptions,0 a terra incognita so far as its terrestrial 

mammalian life is concerned. Glimpses only of its marine or seashore mammalian life are afforded in the Zeuglodon zone 6 of Alabama 

and Florida and in other littoral marine deposits. While this vast 

eastern region contains no known Eocene mammal-bearing deposits, 

it was undoubtedly the scene of a very active continental 0 mammalian 

life from the time of the emergence of the central area toward the 

close of the Cretaceous, or during and after Laramie time. Yet our 

knowledge of the life of eastern North America during the entire 

Eocene is only what we gain by inference from our knowledge of the 

life of the Mountain Region from Montana on the north (47°) to New 

Mexico on the south (36° latitude), a relatively circumscribed area.

Our earliest knowledge of the mammalian life of the Great Plains 

is that suddenly afforded on its extreme western fringe or border in 

lower Oligocene time, and it is indeed a revelation. Again, with the

a For example, Marsh has reported from the supposed Oligocene of New Jersey two species of mammals, Elotherium and Protapirus ( Tapiravus) validus.

b Zeuglodon is an aberrant whale-like form which probably originated in the Eocene of North Africa.

c As pointed out by Suess, North America has been a continent since the close of the Cretaceous, and 

its great land surfaces are older, more permanent, and more extensive than those of Europe. The 

land surfaces of Africa, however, are far older than either.
OP WESTERN NORTH AMERICA. 21

exception of important upper Miocene .("Peace Creek" and "Archer" 

formations) and possibly mid-Pliocene deposits in Florida, the country east of the Great Plains remains unknown until the lower Pleistocene.

These facts, which are often overlooked by paleontologists, have a 

very important bearing on theories as to the source or origin of the 

new forms o£ mammals which suddenly appear from time to time.

RESEMBLANCES AND CONTRASTS BETWEEN MOUNTAIN 

AND PLAINS REGIONS.

Resemblances. Opening with a moderately warm and humid but 

far from tropical climate, with mild winters, the common physiographic and climatic history of both the Mountain and western 

Plains regions was that of progressive elevation, slowly progressing 

aridity, gradual soil denudation and deforestation, progressively 

sharper definition of the winter and summer seasons, concluding 

with destruction of most of the larger forms of life during the lower 

Pleistocene glacial epoch.

Contrasts. The geologic history of the two regions presents some 

strong contrasts.

First, with some exceptions, the Tertiary deposits of the Mountain 

Region are in clearly defined basins drained by the same great river 

systems which drain them to-day, while those of the Plains Region 

are widely scattered over broad areas, with frequent changes in the 

river courses, the present river courses being comparatively modern.

Second, it follows that in the Mountain Region, from the basal 

Eocene to the summit of the upper Oligocene or John Day formation, 

there was little or no working over of the older Tertiary rocks into 

newer deposits, but there exist a number of continuous local depositions. Erosion of these depositions has been retarded fortunately 

in the John Day basin of Oregon by heavy cappings of lava, in the 

Bridger basin by a dense Pleistocene (?) conglomerate, and in the 

Washakie basin by a fine conglomerate. Broad expanses of these 

historic strata have thus been preserved in their original purity and 

continuity for the geologist and paleontologist.

Third, by contrast, in the Plains Region the original very extensive 

Oligocene strata were in part worked over to form Miocene strata, 

and these in turn were in part eroded to form Pliocene strata; again, 

all three contributed to the Pleistocene strata; and finally all four 

are now contributing to the alluvium of the Great Plains. Thus in 

the Plains Region we find Miocene river deposits laid in old Oligocene 

channels, and Pliocene deposits embedded in Miocene channels, as 

well illustrated in Gidley's sections 0 in the Llano Estacado of Texas

a Gidley, J. W., The fresh-water Tertiary of northwestern Texas. American Museum expeditions 

of 1899-1901: Bull. Am. Mus. Nat. Hist., vdl. 19,1903, pp. 617-635.
22 CENOZOIC MAMMAL HORIZONS

(fig. 15, p. 82). This succession of depositions and erosions has rendered the Tertiary geologic history of the Great Plains very complicated, and has .retarded our geologic and paleontologic solutions.

Fourth, owing to the proximity of the volcanic zones, volcanic ash 

and other fine eruptive materials contributed very largely and in 

some basins almost exclusively to the Eocene and Oligocene deposits 

in the Mountain Region, while in the Plains Region, which was 

more distant from the active craters, volcanic-ash deposits were 

occasional, and conglomerates, sandstones, and clays make up the 

main mass of the deposits. In some Plains deposits, however, volcanic ash is a large component.

Fifth, the mammalian life of the Mountain Region was largely 

that of plateaus, uplands, and elevated basins, of streams and lake 

borders, of hillsides, and more or less of the forests. The mammalian 

life of the Plains Region was that of savannas and pampas, of broader 

plains and rivers, with more restricted forests. There was, however, 

no sharp life demarcation, because then, as now, some of the Plains 

types penetrated the Mountains and some of the Mountain types' 

penetrated the Plains.

General homotaxis of some of the Mountain and Plains formations.

Middle Pliocene....

upper Miocene.

Middle Miocene ....

upper Oligocene. 

Upper Oligocene...

Lower Oligocene . . . 

Upper Eocene. .....

Middle Eocene.....

Lower Eocene .....

MOUNTAIN BASIN DEPOSITS.

Geologic. Partly of erosion 

materials; largely of volcanic materials, partly 

eolian, partly deposited 

in water. 

Faunistic. Extinct mammals, chiefly inhabiting a 

mountainous, hilly, forested, lake- and riverborder, w e 1 1-watered 

country.

Deep River,Mont. : Mascall, 

Oreg. 

1" Fort Logan," Mont. . .....

<John Day (upper part), 

1 Oreg. 

John Day (middle and 

lower parts), Oreg. 

Deposits on Pipestone 

Creek, Mont.

Uinta, northern Utah ...... 

{"Washakie," Wyo.........

Bridger, Wyo...... ........

Wind River, Wyo. .........

Wasatch,N.Mex. and Wyo.

Fort Union, Mont.........

GREAT PLAINS DEPOSITS.

Geologic. Largely of water-erosion and wind-erosion materials; partly of 

volcanic materials. 

Faunistic. Extinct mammals, chiefly of an openplains country, traversed 

by broad, slow-moving 

rivers, savanna, partly 

forested, with shallow 

lakes and decreasing rain 

supply.

lican River"), Nebr.

Nebr. 

" Pawnee Creek," Colo.....

Arikaree (Gering Rosebud), Nebr.

White River, S. Dak. (upper 

part). 

White River (lower part), 

of the western plains, of 

South Dakota, Nebraska, 

etc.

Second deposition period of very widespread fluviatile,

flood-plain, and eolian deposits, chiefly 

erosion and volcanic 

materials, on the

kota, Nebraska 

Colorado, and western Kansas. Limited and ' scattered 

deposits in the 

Rocky Mountain 

region.

First deposition (or 

Eocene) period of 

lacustrine, river, and 

flood-plain deposits, 

largely of volcanic

Rocky Mountain basin, chiefly in the

er. Plains deposits

of this period eroded 

away, buried, or unknown.
OF WESTERN NORTH AMERICA. 23

ROCKY MOUNTAIN BASIN 

DEPOSITS

GREAT PLAINS 

DEPOSITS

ZONE

Gtyptotherium

MerycochoeruJ3_

ProinerycochtErus

Dicerntherium.

Coryphodon

and. 

Eohippvs

Pantolambda 

Poty mastodon

Vie.. 1. Composite section of the Tertiary deposits of the West. The thickness of these deposits is 

represented on the same scale throughout. The correlations indicated by dotted lines are preliminary.
24 CENOZOIC MAMMAL HORIZONS

GEOLOGIC HISTORY OF MOUNTAIN BASIN DEPOSITS 

OF THE EOCENE AND OLIGOCENE.

The combination by faunistic correlation of all the Eocene sections, 

as represented in fig. 1, gives a total thickness of 7,200 feet.

The deposits are distinguished by the following chief characters:

1. The axes of the mountain ranges were the same as at present. 

The mountain ranges, in relation to the surrounding country, were 

probably higher than at present, because we must allow for two to 

three million years of erosion.

2. The Eocene drainage systems were broadly the same as the 

modern, namely, the systems of Colorado Kiver, Arkansas River, the 

Bighorn branch of Missouri River, and Columbia River. In details, 

however, the drainage systems have certainly been modified by uplift' 

and erosion.

3. The deposits all lie in the same great mountain basins or mountain valleys in which they were originally deposited. (See PI. I.)

4. Except close to the mountain foothills (e. g., Wasatch of the 

Bighorn Basin) there has been comparatively little Eocene or post- 

.Eocene disturbance, because these deposits are still horizontal or at 

gentle angles with their original horizontal position.

5. The surr6unding mountain ranges were interspersed with active 

volcanic peaks; the upper Colorado River basin especially was surrounded by a circle 6f volcanoes which poured out their lava and 

widely distributed their ashes.

6. From preliminary lithologic examinations the Eocene deposits 

have been found to consist largely, sometimes exclusively, of volcanic-ash materials." The subject has an interesting history: In 

1885-86 Merrill and Peale determined the volcanic-ash origin of the 

"Bozeman lake beds" in Gallatin County, Mont. Peale's conclusions were interesting. 6 These observations are in line with King's 0 

(1876) previous recognition of volcanic-ash strata in the typical 

Wasatch of Evanston, Wyo., immediately underlying the true Coryphodon zone of Marsh, with Wortman's note as to the volcanic-ash 

nature of the Huerfano basin Pliocene, and with a number of obsero It is interesting to note the similar volcanic-ash character of the Santa Cruz, the chief Miocene formation of Patagonia.

6 Peale, A. C., Science, vol. 8, Aug. 20,1886, p. 163. The article concludes as follows:

"Will we not, therefore, have to cut down very materially the great length of time generally believed 

to have elapsed in this region from the beginning of this lacustrine period to the present time, when 

we find that a great portion of the sediment that once filled the lakes is due, not to the products of 

erosion, as has hitherto been supposed, but to repeated showers of volcanic dust? Again, do not these 

volcanic materials, which must have fallen in showers over a large extent of country accumulating 

in some cases in beds 40 to 90 feet thick account for the perfect preservation of the vertebrate remains 

which characterize the formations in so many parts of the West; and is there nqt also suggested one 

possible cause for the extinction of some of the many groups of animals which have at present no descendants in thin region, and whose only remains are the bony fragments found in these lacustrine 

deposits?"

cAm. Jour. Sci., 3d ser., vol. 11, 1876, pp. 478-480.
 OF WESTERN NORTH AMERICA. 25

vations (Barbour, Darton, and others) as to the volcanic-dust composition of certain Oligocene to Pliocene sands in Nebraska, Montana, 

and Colorado. Following Merriam's a determination (1901) of the 

volcanic-ash nature of the deposits of the John Day basin, the next 

important step of recent years in relation to the Eocene lake basins 

is the recognition by Sinclair 6 (1906) that the deposits of the Bridger 

basin, previously described as sandstones and clays, are also chiefly 

of volcanic nature or tuffs. The neighboring Washakie basin deposits 

are of ash (Sinclair, 1907). On preliminary examination the same 

observer finds tuffs in the Torrejon, Wasatch, Wind River, and Uinta, 

as well as in the Bridger; in other words, in the entire Eocene series. 

The lower part of the Wind River formation, however, and probably 

parts of other basin deposits, appear to be true sandstones and clays. 

Veatch c (1906) confirms King's observation that just below the 

typical CorypTiodon zone of Evanston are extensive "white beds" 

largely composed of volcanic ash, which he names the Fowkes 

formation.

7. The manner of deposition of volcanic ash in these various 

basins, whether blown about on a dry surface, in flood plains, or in 

either extensive or shallow lakes, has not" been fully determined. In 

the Bridger formation the ash shows little evidence of prolonged 

water erosion. Merriam rejects the lacustrine theory of the origin 

of the John Day formation and speaks of "showers of ash, with tuff 

deposits on a plain occupied in part by shallow lakes."

8. Admirable studies of the John Day Oligocene, in most of its 

biotic and geologic aspects, have been made by Merriam,a Sinclair,** 

and Knowlton/ (See p. 67.)

9. The Bridger formation, 1,800 feet in thickness, is the only Eocene 

deposit which has been exactly examined-^ from the standpoint of 

geology, petrography, and paleontology. Wind-blown volcanic ash, 

glass, and eruptive feldspar are large ingredients of this formation, 

which contains no erosion materials from the adjacent Uinta Mountains, such as we should expect to find. There is evidence of the 

direct deposition of the ash in water, with some working over of the

a Merriam, J. C., A contribution to the geology of the John Day basin: Bull. Dept. Geology, Univ. 

California, vol. 2, No. 9, April, 1901, pp. 269-314.

f> Sinclair, W. J., Volcanic ash in the Bridger beds of Wyoming: Bull. Am. Mus. Nat. Hist., vol. 22, 

1906, pp. 273-280.

c Veatch, A. C., Geography and geology of a portion of southwestern Wyoming, with special reference 

to coal and oil: Prof. Paper U S. Geol. Survey No. 56,1907.

d Sinclair, W. J., New or imperfectly known rodents and ungulates from the John Day series: Bull. 

Univ. California, Dept. Geology, vol. 4,1905, pp. 125-143.

«Knowlton, F. H., Fossil flora of the John Day basin, Oregon: Bull. U, S. Geol. Survey No. 204, 

1902,153 pp.

/ The writer planned this survey in preparation for the United States Geological Survey monograph 

on the titanotheres, desiring to ascertain whether or not the Eocene titanotheres were horizontally 

distributed, i. e., in vertically successive life zones. As conducted by and reported on by Messrs. Matthew, Granger., and Sinclair, partly for the United States Geological Survey, but chiefly for the American Museum expeditions, it succeeded far beyond our most sanguine anticipations.
26 CENOZOIC MAMMAL HORIZONS

coarser materials by streams into the so-called sandstones, while the 

finer materials, constituting the so-called clays, are actually tuffs. 

Proofs of temporary lacustrine conditions, or of- prolonged high water 

on base-level, are found in the very widely extended so-called white 

layers containing calcite and flint; these divide theBridger formation 

into five levels (A, B, C, D, E), each characterized by distinctive 

specific forms of mammalian and reptilian life. These levels demonstrate periodic risings of the water level in this basin.

10. As the fossil mammals which all these Eocene mountain deposits contain are carefully compared and studied, we nearly, if not quite, 

demonstrate another great fact, namely, that these deposits were 

successively formed, in one basin after another, throughout the 

Eocene period; in a number of cases, fortunately, there was a time 

overlap in other words, before one deposition closed another began. 

When fully explored they will thus afford a nearly continuous history 

of the vertebrate life of the Mountain Region during the Eocene and 

Oligocene epochs.

GEOLOGIC HISTORY OF THE GREAT PLAINS DEPOSITS 

OF THE OLIGOCENE TO LOWER PLEISTOCENE.

Extent. The Oligocene to Pleistocene deposits immediately overlie the various divisions of the Cretaceous and form the surface of the 

plains at different points from 200 to 300 miles east of the Rocky 

Mountains, from British Columbia on the north to the Mexican plateau 

on the south, with a combined maximum thickness of about 2,000 

feet. Their central area is best shown in Carton's preliminary geologic map of'the central Great Plains. a

History of opinion as to mode of deposition^ The lacustrine-origin 

theory as to the Great Plains deposits was entertained by Owen, King, 

Hayden, Leicly, Cope, Marsh, Scott, and Darton; it reached its climax in King's proposal to give names to each of the great successive 

lakes, beginning with those in the Mountain Region. This theory of 

lake basins of very large extent on the Great Plains has been abandoned in the light of more exact paleontologic and geologic study.

Among the geologists, Johnson, 0 Gilbert/ Haworth, and especially 

Davis, who reviewed the whole subject in a broad and critical way, 

have advocated a fluviatile and flood-plain origin. Hatcher, Fraas, 

and recently Darton have also set forth strong reasons for fluviatile

a Preliminary report on the geology and underground-water resources of the central Great Plains: 

Prof. Paper U. S. Geol. Survey No. 32,1905, pi. 35.

*> The history of opinion is fully traced in Davis, W. M., The fresh-water Tertiary formations of the 

Rocky Mountain region: Proc. Am. Acad. Arts and Sci., vol. 35, No. 17, March, 1900, pp. 346-373.

c Johnson, W. D., The High Plains and their utilization: Twenty-first Ann. Kept. U. S. Geol. Survey 

pt. 4,1901, pp. 601-741; Twenty-second Ann. Kept., pt. 4,1902, pp. 631-669.

d Gilbert, G. K., The underground waters of the Arkansas Valley in eastern Colorado: Seventeenth 

Ann. Kept. U. S. Geol. Survey, pt. 2, pp. 553-601.
OF WESTERN NORTH AMERICA. 27

or river-channel and flood-plain origin; for river-channel, backwater, 

lagoon, and shallow-lake origin (Fraas); for flood-plain and eolian 

origin (Hatcher, 1902") of various portions of these scattered deposits 

(Darton).

Among paleontologists, Matthew (1899, b 1901 c) especially attacked 

the lacustrine theory of the origin of the White River clay of Colorado 

on both paleontologic and geologic grounds, and set forth cogent reasons for a diametrically opposed eolian theory, comprising a river and 

flood-plain origin for the sandstones, and a partly backwater and 

lagoon but chiefly eolian sedimentation for the clays. His paleontologic analysis shows that the fine Oligocene clays contain chiefly the 

terrestrial and plains animals and thus represent overflow and stillwater formations, while the sandstones traversing these clays are contemporaneous, but contain chiefly the forest and fluviatile animals, and 

thus represent rapid-water (river) formations.

The paleontologic evidence taken alone strongly favors the theory 

of dry-land sedimentation of the so-called Oligocene clays, because the 

entire fauna is terrestrial, while aquatic types are wholly wanting. 

Thus Matthew d concludes in favor of an eolian theory:

But the nature of the organic remains, where such have been found, seems to 

definitely negative the idea of any vast lake, and to favor less the theory of a series of 

lagoons and swamps than that of a broad, open, and comparatively dry plain, with shallow, probably wooded rivers meandering over parts of it, and deposits partly or chiefly 

brought by rivers, but in large part redistributed over the higher sodded grass land by 

the agency of the wind. This would mean an approximation to the present conditions 

of climate, though probably not so dry as that of the region now is.

Osborn,e after a personal survey of the South Dakota Oligocene and 

lower Miocene section (see PL III) in 1906, in general supports the 

view of Matthew and Hatcher that the lacustrine theory is entirely 

untenable, but he holds that the eolian theory for the White River Oligocene deposits is also untenable. The chief geologic evidence against 

the eolian theory as applied to certain areas of the Oligocene or Brule 

clay (Oreodon and Leptauchenia zones) is the absolutely regular horizontal banding, miles in extent, which points to deposition in tranquil sheets 

of water. In fact, this banding of the light-colored finer portions of 

the Brule clay, and even of portions of the underlying Chadron formation, militates as strongly against the eolian theory as the paleontologic evidence militates in favor of it. These buff, horizontally banded 

strata are, on certain levels, abruptly traversed by grayish to greenish

a Hatcher, J. B., Origin of the Oligocene and Miocene deposits of the Great Plains: Proc. Am. Philos. 

Soc., vol. 41,1902, pp. 113-132.

6 Matthew, W. D., Is the White Eiver Tertiary an eolian formation? Am. Naturalist, vol. 33, 1899 

pp. 403-408.

c Matthew, W. D., Fossil mammals of the Tertiary of northeastern Colorado: Mem. Am. Mus. Nat. 

Hist., vol. 2, pt. 7,1901, pp. 359-308 (conditions of deposition).

d Op', cit., 1901, p. 364.

« Tertiary mammal horizons of North America: Bull. Am. Mus. Nat. Hist., vol. 23,1907, p. 237.
28 CENOZOIC MAMMAL HORIZONS OF WESTERN NORTH AMERICA.

river-channel beds of coarse materials, from 700 feet to a mile in 

width, with an easterly direction. The most tenable theory at present seems to be that of periodic overflow deposition in very shallow 

sheets of water, too transitory or seasonal to support any of the 

aquatic animals such deposition as is left by the annual overflow of 

the Nile, for example. The nilometer at Roda shows an annual accumulation of silt of 0.12 centimeter, equivalent to 12 meters in ten 

thousand years, as cited by Lyons a and by Beadnell.6

Summary. The sum of the present opinion appears to be this: The 

topography of the Plains Region was in Oligocene to lower Pleistocene time, as now, level or gently undulating, not mountainous. 

On the gentle eastward slopes of the Rocky Mountains and the Black 

Hills were borne broad streams with varying channels, backwaters, 

and lagoons, sometimes spreading into shallow lakes but never into 

vast fresh-water sheets. Savannas were interspersed with grasscovered pampas, traversed by broad, meandering rivers which frequently changed their channels.

This accounts for the presence of true conglomerates, true sandstones, calcareous grits, gypsum, fine clays, fuller's earth, fine loess, 

eolian sands, and even, far out on the plains of Nebraska G and Kansas, 

widespread deposits of volcanic dust, wind borne from distant craters 

in the mountains to the west and southwest. In the early Oligocene 

and Miocene the deposits were chiefly fluviatile or river sandstones 

and conglomerates interspersed with fine flood-plain or overflow 

deposits, perhaps locally lacustrine, partly of volcanic ashes. This 

interpretation is presented in PI. Ill, which has been prepared to 

show the actual relations of the unstratified stream-channel deposits 

to the finer and partly stratified surrounding deposits. These rocks 

still await petrographic analysis.

As the desiccation or aridity of the country increased, the mountain-fed rivers became smaller and narrower, while the eolian or loess 

deposits apparently became more common, beginning in the middle 

Miocene. The deposits also became more and more restricted in 

extent as the Miocene advanced. The newer river channels cut down 

into the older series, thus using the erosion materials a second time.

Thus geology and petrography unaided fail to complete the picture. 

Paleontology goes hand in hand with these sciences to restore the true 

picture of former conditions on the Great Plains; but far more extensive petrographic and paleontologic investigation than has as }^et been 

made is necessary to establish a final geologic theory.

a Lyons, H. G., The physiography of the River Nile and its basin: Survey Dept. Egypt, Cairo, 1906, 

pp. 313, 317, 334.

6 Beadnell, H. J. L., The topography and geology of the Fayum province of Egypt: Survey Dept. Egypt, 

Cairo, 1905. p. 80.

c See Barbour, E. H., The deposits of volcanic ash in Nebraska: Proc. Nebraska Acad. Sci., 1894-95. 

The heaviest beds and the coarsest ash occur in the southwestern counties. Even as far east as Missouri 

River (Cuming County) there are beds 7 feet in thickness.
CHAPTER II.

TIME CORRELATION OF MAMMAL-BEARING HORIZONS. 

THE TWO GRAND PROBLEMS.

American correlation. The first problem is the chronologic correlation of the purely fresh-water American horizons with one another, a 

problem which in exact form has hitherto made slow progress owing 

to the very loose methods of collecting fossils for purely anatomic and 

descriptive purposes without closely recording geologic levels and

other geologic data. Now, thanks to the revival of the more exact 

methods which characterized some of Hayden's and Leidy's work on 

the Great Plains, there is promise of very rapid progress. Among 

paleontologists we are indebted to Scott, Wortman, Matthew, Gidley, 

Merriam, Sinclair, and others, but especially to Matthew's very accurate and complete manuscript faunal lists. 0 Accurate faunal leveling 

began with Hatcher's explorations of the Chadron formation (Titanotherium zone), and has been the invariable rule of the American 

Museum expeditions since 1901.

American and Eurasiatic correlation. The second problem, following especially Cope (1879-1884), Marsh (1891), Filhol (1885), 

Scott (1888-1894), and Osborn (1900), is the approximate chronologic 

correlation of American horizons with Eurasiatic vertebrate horizons 

and thus indirectly with European marine invertebrate horizons, 

which is rendered possible by the well-known alternation of marine 

and fresh-water horizons over large parts of central' Europe. This 

indirect method of correlation with the European marine stages is 

facilitated by the partial alternation of marine and fresh-water formations in Florida, as studied by Dall, 6 and will in time establish the 

western American Tertiaries in the geologic world time scale.

When these two grand problems of American correlation and. of 

American-Asiatic-European-African correlation are worked out we 

shall be able (1) to establish a complete and very accurate geologic

o The most thorough previous correlation of the American Tertiaries is that of Matthew, A,provisional 

classification of the fresh-water Tertiary of the West: Bull. Am. Mus. Nat. Hist., vol. 12,1899, pp. 19-75. 

At this writing a second edition Is in. preparation, the partly completed manuscript of which has been 

placed at my service by Doctor Matthew. It will be printed herewith as a,n appendix. IT. F. 0. (See 

pp. 91-120.)

t> .Dall, W. H., Geological results of the study of the Tertiary fauna of Florida, 1886-1903: Trans. Wagner Free Inst. Sci., Philadelphia, vol. 3, pt. 6,1903. pp. 1541-1620. Also, A table of the North American 

Tertiary horizons, correlated with one another and with those of western Europe, with annotations: 

Eighteenth Ann. Kept. U. S. Geol. Survey, pt. 2,1898, pp. 323-348.

 29
30 CENOZOIC MAMMAL HORIZONS

time scale for the entire Tertiary and (2) to speak with precision regarding the time of successive migrations, and it is possible that we 

shall be able (3) to describe our subdivisions in the terms of the stages 

or etages employed by our European confreres. These are results 

toward which the writer has worked for many years in cooperation 

with many colleagues in this country and in Europe. 0

METHODS OF CORRELATION.

Bases. The faunistic bases which the writer laid down a for European and American correlation were:

1. Percentages of common genera and species. To this. families 

should now be added.

2. Similar stages of detailed evolution in related forms, e. g., 

Eocene Equidse, Miocene Rhinocerotidae.

3. Simultaneous introduction of new forms by migration, e. g., 

Mastodontinae in middle Miocene.

4. Predominance or abundance of certain forms, e. g., Promerycochmrus in all lower Miocene deposits.

5. Convergence and divergence of faunas in comparison with Europe 

and Asia, e. g., lower Eocene, Oligocene, middle Miocene, middle 

Pleistocene.

6. Extinction of certain forms, e. g., Steneofiber, in lower Miocene. 

Similarly the correlation of the Tertiaries of northwestern America, 

inter se, should be based on 

1. Presence of similar specific and generic stages.

2. Evidence of similar local evolution.

3. Dominance or scarcity of similar animals in the fauna.

4. Disappearance or apparent extinction of similar forms.

5. First appearance of similar forms.

It should always be kept in mind that the appearance of a new 

mammal in any of the Plains or Mountain deposits may occur by 

migration from one of several possible sources, namely:

1. From the unknown Plains or Mountain regions of eastern North 

America or of northern North America.

2. From Europe or Eurasia as a whole.

3. From South America.

4. From Africa.

5. From Australia via Antarctica.

Sources of error. This kind of evidence as to the bases of correlation is subject to two great limitations:

First, imperfections in our records, or the possible presence of 

animals which have existed in contemporaneous, earlier, or later

« Correlation between Tertiary mamma.l horizons of Europe and America: Ann. New York Acaxl. Sci., 

vol. 13,1900, pp. 3-44. Also, Trial sheets of typical and homotaxial Tertiary horizons, issued in 1897,. 

1898, and 1900.
OF WESTERN NORTH AMERICA. 31

geologic stages, but which have not been discovered, owing to the 

accidents of deposition or to occurrence remote from centers of 

deposition. We are too apt to assume the absence of a mammal from 

the entire continent because it has not been found in what was formerly a very restricted region. Many forms previously considered 

absent from the American Eocene have very recently been discovered; for example, the animals related to 'the armadillos or 

Dasypodidse, found in the Bridger.

Second, the different contemporary conditions of environment and 

habitat in different parts of the Mountain Region and of the Great 

Plains Region; that is, local differences of habitat, differences of 

longitude or of east and west distribution, differences of latitude 

or of north and south distribution, differences of altitude or vertical 

distribution in short, such differences as exist to-day render correlation somewhat uncertain. Thus, the arboreal primates are very 

common in the Eocene Mountain deposits, but no trace of them is 

found in the Oligocene Plains deposits.

PRELIMINARY CORRELATION OF THE EOCENE AND 

OLIGOCENE MOUNTAIN DEPOSITS.

Correlation of the Mountain Region basins of the Eocene is of 

necessity almost exclusively paleontologic owing to the uniform 

repetition of similar geologic and petrographic conditions in the 

successive basins.

These deposits, as above noted, fortunately overlapped each other 

in time that is, before one ceased, its more or less distant neighbor 

began. The writer and others are now collecting exact data for 

estimating these overlaps. Fig. 1 presents the writer's preliminary 

correlation of the Eocene and Oligocene deposits, based on personal 

studies, with the able cooperation of Matthew, Granger, Sinclair, 

Loomis, and others.

The chief omissions, which will soon be supplied, are (1) the Fort 

Union section of south-central Montana (Douglass, 1902), with its 

fauna equivalent to the Torrejon; (2) the typical Wasatch (Corypliodon zone) section, Evanston, Wyo. (Veatch, 1907); and (3) the 

typical Wind River section (Loomis).

PRELIMINARY CORRELATION OF THE OLIGOCENE TO 

LOWER PLEISTOCENE MOUNTAIN AND PLAINS DEPOSITS.

The geologic and paleontologic correlation of the Great Plains 

deposits above the lower Miocene is even more difficult owing (1) 

to the irregular nature of these deposits and (2) to our present lack 

of exact analysis of the mammalian fauna.

The accompanying preliminary correlation (fig. 10), based on the 

researches of Hayden, Leidy, Cope, Scott, ^Wortman, Merriam,
32 CENOZOIC MAMMAL HORIZONS OF WESTERN NORTH AMERICA.

Gidley, Douglass, Peterson, Sinclair, and others, was prepared by 

Dr. W. D. Matthew (May, 1906), and embodies some alterations 

by the writer and by Messrs. Peterson and Douglass (September, 

1906). It is to be regarded as largely tentative and incomplete. 

Figs. 1 and 13 bring out.the following two facts of chief importance: 

First, that through examination and comparison of the fauna of 

local horizons we shall probably be enabled to establish a complete 

continuity of mammalian life for the entire Eocene, Oligocene, and 

Miocene epochs of North America in a general sense, but this will 

never apply to the fauna of the whole Tertiary of either the Great 

Plains or the Mountain Region.

Second, that while the chief faunistic lacunae at present are in the 

American Pliocene, these gaps will probably be filled as time goes on, 

just as the great lower Miocene gaps which existed only a few years 

ago have been filled.
CHAPTER III. 

WESTERN AMERICAN CENOZOIC HORIZONS.

EOCENE.

I. FIRST FAUNAE PHASE.

Archaic Mesozoic mammals with partly South American, partly European

affinities.

POST-CRETACEOUS OR BASAL EOCENE (EUROPE, ETAGE THANETIEN).« 

1. PUERCO FORMATION; POLYMASTODON ZONE.

(Fig. 1; PL I-)

HOMOTAXIS.

North America. Puerco formation (500 feet), San Juan basin, 

northwestern New Mexico.

South America. A contemporary or previous (i. e., Cretaceous) 

land connection with South America is indicated by the occurrence of 

similar mammals in the Notostylops zone, Upper Cretaceous or basal 

Eocene of Patagonia. Additional evidence of South American connection is afforded by the subsequent occurrence of animals related to 

the Edentata-Dasypoda in the American middle Eocene.

Europe. No European mammal fauna of this earliest stage is 

known, therefore no conclusions as to homotaxis can be drawn. It 

corresponds broadly to the Thanetien.

FAUNA. b

In New Mexico and Montana are found small archaic mammals'3 

evolving from Cretaceous, Jurassic, and Triassic ancestors. Multituberculata, which originated in the Triassic, 3 families. Two orders 

of archaic ungulates (1) Amblypoda-Periptychidse, (2) Condylarthra-Phenacodontid£e. Archaic Carnivora-Creodonta, 3 families: 

(1) Oxyclsenidse, (2) Mesonychidse-Triisodontinse, (3) Arctocyonidae

"Throughout this paper the French stages Thandtien, Sparnacien, etc., are inserted merely to indicate approximate homotaxis with Europe.

b Matthew, W. D., A revision of the Puerco fauna: Bull. Am. Mus. Nat. Hist., vol. 9,1897, pp. 259-323. 

(See Appendix to.this volume, p. 91.)

c In the following pages '' Archaic mammals " include members of the orders Multituberculata, Marsupialia, Inscctivora, Tseniodonta-Edentata, Amblypoda, and Condylarthra, of Mesozoic origin (hence 

Meseutheria Osborn) and typically of Mesozoic and early Eocene radiation. "Modernized mammals" 

include members of the orders Primates, Carnivora, Fissipedia, Rodentia, Hyracoidca, Proboscidca, 

Perissodactyla, and Artiodactyla, which are in general of higher type and of Cenozoic origin and radiation (hence Ccncutheria, Osborn).

56092 Bull. 361 09 3 33
34 CENOZOIC MAMMAL HORIZONS

(Clsenodon protogonoides). Edentata-Taeniodonta, with enameled 

teeth, 2 families: (1) Stylinodontidae, (2) Conoryctidae.

Summary of. genera and species.

Genera. Species.

Archaic Triassic mammals................................. 3 5

Archaic Cretaceous mammals................................ 15 24

Total archaic mammals.............,.......:........ 18 29

Modernized or distinctively Tertiary mammals.............. 0 0

The Puerco is a fauna wholly of Mesozoic origin, and mostly 

destined to disappear; not a single representative or ancestor of any 

existing order of Tertiary mammals is certainly known. Cope's 

opinion0 that many of these mammals were ancestral to the modernized mammals lacks direct confirmation at present. Other paleontologists, however, are inclined to connect certain of the creodont 

families with the modern Carnivora. These and other ancestral connections may be demonstrated in future.

Negatively, therefore, the Puerco is distinguished by the absence 

of primates, rodents, true carnivores, specialized insectivores, artiodactyls, perissodactyls, etc. 6 'This generalization has hardly less 

important bearings on paleogeography than on paleozoology.

2. TORREJON FORMATION; PANTOLAMBDA ZONE.

.(Fig. 1; PI. I.) 

HOMOTAXIS.

North America. 1, Torrejon formation (300 feet), continuous with 

Puerco formation, San Juan basin, northwestern New Mexico. 2, A 

portion of the Fort Union formation, Montana (Douglass,c Farr).

Europe. Thane"tien or Cernaysien. Homotaxis with Europe is 

indicated by the common presence in France and North America of 

similar stages of evolution in representatives of 3 families, namely, 

(1) Plagiaulacidae, (2) Arctocyonidae, and (3) Mesonychidae-Triisodontinae. Other identifications are very uncertain.^

FAUNA. 6

Like the Puerco, this is almost exclusively a. Mesozoic fauna, 

destined to become extinct during the Eocene. The known excep-

» The opposite theory of the nonancestry of the Puerco-Torrejon to the modern fauna was developed 

by the writer, in Rise of the Mammalia in North America: Proc. Am. Assoc. Adv. Sci., vol. 42,1893 (1894), 

p. 214. See also Ten years' progress in mammalian paleontology: Compt. Rend. 6° Cong. intern, 

zoologie, Berne, 1904, pp. 86-113.

6 Certain incompletely known mammals (e. g., species of Mioclsenus and Pentacodon, of the Oxyclsenidse and Mixodectidse) may prove to be Insectivora. W. D. M.

c Douglass, Earl, A Cretaceous and lower Tertiary section in south-central Montana: Proc. Am. 

Philos. Soc., vol. 41, pp. 207-224. Also, New vertebrates from the Montana Tertiary: Ann. Carnegie 

Museum, vol. 2,1903, pp. 145-200.

dOsborn,-H. F., A review of the Cernaysian Mammalia: Proc. Acad. Nat. Sci. Philadelphia, May 6, 

1890, pp. 51-62.

« Matthew, W. D., A revision of the Puerco fauna: Bull. Am. Mus. Nat. Hist., vol. 9,1897, pp. 259-323. 

(See Appendix to this volume, p. 91.)
OF 'WESTERN NORTH AMERICA. 35

tions in surviving types are the pro-Carnivora-Miacidse, which first 

appear at this stage. Others will be discovered.

Mammals of larger size, mostly evolved from the Puerco mammals. 

Last survivors of the Multituberculata. Edentata-Tseniodonta of 

larger size. Of archaic Ungulata, 2 orders and 3 families: (1) Condylarthra-Phenacodontidae, (2) Amblypoda-Periptychidse, (3) Amblypoda-Pantolambdidae. Of the latter, Pantolambda is supposed to be 

ancestral to the Coryphodontidse of the Wasatch. Carnivora-Creodonta, 4 families: (1) Mesonychidse- Triisodon and Dissacus, (2) Oxyclsenidae, (3) Arctocyonidse, (4) pro-Carnivora-Miacidae. The primatelike Indrodon and aberrant Mixodectes are of unknown relationships; 

they are possibly 'Insectivora.

Summary of genera and spedes.

Genera. Species.

Archaic Triassic stock..................................... 3 4

Archaic Cretaceous stock..................................... 21 36

Total archaic stock.................................. 24 40

Modernized Tertiary stock................................. 1 1

II. SECOND FATJNAL PHASE.

First modernization Invasion of the archaic by the modern fauna South 

American land connection interrupted Close faunal connection with western Europe Initial elimination of the archaic fauna in competition with 

the modern.

In the period of the deposition of the Wasatch formation, independent deposits were formed in western Wyoming, northern Wyoming, and New Mexico. A momentous change occurs, namely, the 

sudden modernization of the mammalian fauna of the Mountain 

Region.

In the San Juan basin of northwestern New Mexico, after a barren 

deposition interval of only a few hundred feet between fossiliferous 

Torrejon and Wasatch levels (see fig. 1), there appear representatives of ancestors of 4 or 5 modern orders, including 11 new families, 

2 of which persist to the present time. European paleontologists 

usually attribute the origin of this modernized fauna to North America, but this is without evidence; it is certain that it originated 

neither in South America nor in Africa. There remain four possible 

sources; these animals may have entered the central Mountain 

Region by migration (1) from the Great Plains Region, or (2) from 

the more northerly American Mountain Region, or (3) from the 

northerly Eurasiatic Region, or (4) from the northerly AmericanAsiatic land mass.

In the writer's judgment, the simultaneous and sudden appearance 

in North America, latitude 40°, and in western Europe, latitude 

50°, of a similar fauna favors the fourth theory, namely, that of the 

intermediate or North American-Asiatic or Holarctic origin of this
36 CENOZOIC MAMMAL HORIZONS

fauna. It must be remembered that while there is no evidence of a 

"Holarctica," or north polar continent, similar to the "Antarctica" 

in the south, there was certainly a great American-Asiatic land mass 

to the north, of temperate climate, favorable to the evolution of mammalian life. The vast region between parallels 50° and 70° is also a 

terra incognita until the mid-Pleistocene. There is every reason to 

believe that even to the north this region was through the whole 

pre-Pleistocene Tertiary highly favorable to mammalian life, otherwise the faunal continuity between Europe and western America 

could not have been sustained by-constant intermigration. Wortman a and others have especially advocated the theory of a northerly 

or Arctic Circle land mass as a source of evolution and southward 

migration. »

The actual origin of this modernized fauna which suddenly appears 

in North America and Europe is, however, hypothetical and will not 

be determined until Eocene fossil mammal beds in northern portions 

of America and Asia shall have been discovered.

LOWER EOCENE (EUROPE, ETAGES SPARNACIEN, YPRESIEN).

3. WASATCH FORMATION; CORYPHODON ZONE.

(Figs. 1-4; PL I.)

HOMOTAX1S.

North America. 1, Typical Wasatch (in part), Knight formation, 

Veatch (1,750 feet), western Wyoming. 2, Wasatch near Black 

Buttes, Washakie basin, Wyoming. ' 3, Wasatch of the San Juan 

basin of northern New Mexico (1,500 feet). 4, Wasatch of the Bighorn Basin of northern Wyoming (2,391 feet, Loomis). 5, Lower 

portion of the Huerfano formation near Spanish Peaks, Colorado.

South America. No South American affinities are known.

Europe. Strong affinities with the fauna of the etage Sparnacien 

and especially with that of the etage Ypresien (Londinien) of France 

are found in the evolution of the archaic and in the sudden appearance of the modernized Mammalia of this period.

The Sparnacien (Soissonais inferieur) includes in France the 

deposits of Soissons, Meudon, and Vaugirard; in England, the Woolwich beds and lower London clay. The Ypresien (or Soissonais 

superieur) of France includes deposits of Ay and Cuis. It is in this 

stage that the European modernization becomes marked by the 

sudden appearance of Primates, Rodentia, 2 families, PerissodactylaLophiodontidse and Artiodactyla-Dichobunidse. The Lute"tien infe'- 

rieur of France corresponds approximately with the American upper 

part of the Wind River.

a Wortman, J. L., Studies of Eocene Mammalia in the Marsh collection, Peabody Museum; Part II, 

Primates: Am. Jour. Sci., June, 1903, 4th ser., vol. 15, pp. 419-436.
OF WESTERN NORTH AMERICA. 37

The general parallelism of'France, England, and North America 

is indicated (1) by the common presence in this period of similar

FIG. 2. Map of southwestern Wyoming and northern Utah, showing partial areas of the Wasatch 

Wind River, Bridger, and Uinta formations. Extensive areas of the Wasatch are purposely omitted. 

A, B, lines of sections by F. B. Loomis.

stages in archaic mammals among Creodonta: Mesonychidae, Palseonictidse, ?Arctocyonidse, and Oxyaenidse; among Amblypoda: Cory-
38 CENOZOIC MAMMAL HORIZONS

phodontidse; (2) by the sudden appearance of the four Tertiary 

orders, (a) Perissodactyla-Equidae a and -Lophibdontidse, (&) Artiodactyla, (c) Primates, and (d) Rodentia.

BASIN WASATCH BIGHORN OFTHE

C 

790'

315'

B 

335'

A 

949'

730' 

,85'

|~

^^iiip^^f^ik

.JiX-jii-fiLii.-.'.^:.:^!.'? 

iiil^lsSHISi! JLambdothei 

^^^^i-i^i zone

BUFFALO A4SWv:-:^^V:V:V:--UV:':V::v;.vB

'UPPER TATMAN'MOUNTA/N 'LEVEUiixA.

£Z-EIr-E^-E^-£IE-EZ-EIE-EE-£^5p

LOWER TATMAN MOUNTAIN -LEV£U=.

E-^^^S^^ErE^f^EHEj^Ei^SS^E

 ,m Paramys 

^"^ Coryphodon (rare) 

Lambdother/um pr/maerum 

Phenacodus 

Eohippus cristatus 

Heptodon

Coryphodon zone 

Pslycodus 

Qxyaena 

Anacodon 

£oh/ppus (very abundant) 

Systemodon 

\ Coryphodon (very abundant)

^ :-'.---!-:^v.:v.::^:.:.:.i-A:.v.:^.:-:.x-;.:-M!v.:-A-v-:^-M-;-'Ai| OIHOpa

^J^^i^^l^^Tfj^VHf-K^V/^T

;, W'S^^MMSWSM-ZK-SSS®

^\ Hyopsodus

IjljJA Palaeictops

vvS^S Paramys

FIG. 3. Composite columnar section of the Wasatch formation of Bighorn Basin, compiled from sections by F. B. Loomis. See section A, fig. 2. Total thickness 2,391 feet.

Other faunal identifications with Europe are premature. With the 

exception of the archaic and modern families above listed, the European families and subfamilies are different from the American so far

a The Equidse of the Sparnacien are more primitive than the oldest Wasatch species.
OF WESTERN NORTH AMERICA. 39

as known. H. G. Stehlin a supports the writer's opinion that Riitimeyer was too prone to identify European with American genera;

Types of Eohippus Index

" Phenacodus primaevus 

" Coryphodon radians 

" " semldnctu.s 

" » laticeps

Volcanic ash or white beds

Plants.characteristic 

of Denver -formation

_ Plants and 

^= invertebrates 

of Montana 

age

FIG. 4.' Columnar section showing the relations of the typical Wasatch section, including the Knight 

formation (near Knight, Wyo.), or Coryphodon zone, to the overlying and underlying formations. 

After Veatch, 1907.

this removes the American resemblances supposed to exist in the 

Egerkingen fauna, which now proves to be of middle Eocene (Lutea In letter dated July, 1906, Doctor Stehlin states that he is himself engaged in the study of migrations. He, too, finds strong evidence (1) for a lower Eocene connection between America and 

Europe, (2) for a very decided separation during the middle and upper Eocene, and (3) for a renewed 

connection in the Oligocene and a great Oligocene faunal interchange. These are substantially the 

views adopted in the present paper.
40 CENOZOIC MAMMAL HORIZONS

tien) age. The supposed "americoids," Calamodon, Phenacodus, 

Euprotogonia, Hyopsodus, Pelycodus, etc., are all European animals.

FAUN A. a

The Wasatch fauna consists of a nearly equal or half-and-half mingling of°(l) archaic mammals, including 9 families which evolved 

from the Puerco-Torrejon fauna, with (2) ancestors of the modernized mammals, including 11 families. From this stage onward we 

have to consider these two great elements in the fauna separately.

Summary of genera.

Persistent Triassic mammals....................................... 0

Other archaic ft mammals......................................... 22

Modernized mammals............................................ 16

38

There is thus at this period a slight predominance in number of 

the archaic mammals over the modernized, but 'the individual 

archaic mammals greatly predominate in size.

The surviving archaic or Puerco-Torrejon mammals. Some of 

these mammals, such as Coryphodon, are of large size. The Multituberculata disappear. Of the Edentata-Taeniodonta, 3 genera of 

the Stylinodontidae. Of the archaic ungulates, 2 orders and 3 families 

are represented: (1) Amblypoda-Coryphodontidae, as successors to the 

Pantolambdidae; (2)Condylarthra-Phenacodontidse; (3) CondylarthraMeniscotheriidae. Of the Creodonta-Carnivora there occur 5 families, 

namely, Palasonictidae, Oxyaenidae, Hyaenodontidae, Mesonychidae, 

and Arctocyonidae; 4 of these families also occur in France.

The Tertiary or modernized mammals. These mammals are mostly 

of small size, including the successors of the supposed Torrejon proCarnivora-Miacidas, a family which now branches out into several 

genera. No other Carnivora. True Primates, 2 families. Rodentia, 

1 genus, Paramys with sciuroid teeth. Insectivora, 2 or 3 families, 

one of doubtful affinity. Among Ungulata-Perissodactyla, 3 families, 

Equidae, Tapiridae, Lophiodontidae. Among Ungulata-Artiodactyla, 

1 family. There are thus 11 families among the modernized mammals, 

only two of which (Equidae and Tapiridae) persist to the present time.

« Osborn 'H. F., and Wortman, J. L., Fossil mammals of the Wasatch and Wind River beds: Bull. 

Am. Mus. Nat. Hist., vol. A, 1892, pp. 81-147.

Loomis, F. B., Origin of the Wasatch deposits: Am. Jour. Sci., May, 1907, 4th ser., vol. 23, pp. 356-3G4. 

See Appendix, p. 91.

o See footnote, p. 33.
OF WESTERN NORTH AMERICA. 41

3a. WASATCH OF THE BIGHORN BASIN.

(Figs. 1-3; PI. I.)

Loomis a examined the Wasatch of the Bighorn Basin when the 

question of epicontinental versus lake deposition was uppermost in 

the minds of all. By a careful analysis of the fauna, combined with 

an exact study of the geologic section, he dismisses the lake theory 

entirely. Geologically, as displayed in fig. 3, the section is 2,391 

feet thick, divided into lower, middle, and upper levels, all showing 

flood-plain rather than eolian characteristics, but indicating different 

rates of deposition and consequent longer or shorter exposure of the 

deposits to the sun and air. Only the. middle or red beds are decidedly fossiliferous, and they seem to have been exposed longest to 

the air, leaving the bones of terrestrial animals on the flats; they contain the typical Wasatch, Coryphodon and EoUppus fauna, Occasionally truly aquatic animals, such as crocodiles, fishes, and turtles, 

becoming stranded or inclosed in lagoons far from the river, mixed 

their remains with those of the land animals. Loomis's approximate 

analysis of the natural habitat of the total vertebrate fauna is: 

Aerial, 3 per cent; terrestrial and arboreal, 77 per cent; amphibious, 

12 per cent; aquatic, 10 per cent.

.Remains of Eofiippus, typical of a plains or partly open country, 

alone make up 32 per cent of the total fauna. To this should be 

added the Perissodactyla-Lophiodontidae-Helaletinae (Heptodon), and 

some of the Condylarthra-Phenacodontidae, which are very lightfooted forms. The primitive Titanotheriidse (LambdotJierium') of the 

period may have been hard-ground dwellers, because their feet are 

more slender and contracted than those of the modern tapir, while the 

Amblypoda-Coryphodontidse were certainly marshy-land dwellers 

and perhaps partly amphibious or stream dwellers, although this is far 

from demonstrated. As to relative age, Loomis fixes very positively 

the typical American Wasatch fauna, -or chief Eohippus and Coryphodon zones of Tatman Mountain, as only 100 to 200 feet below the 

beds of the Buffalo basin. The deposits in the Buffalo basin show, 

1,000 feet below the summit, a decided approach if not actual synchronism to the lo.wer deposits of the Wind River valley in the presence 

of Lcimbdotherium and in the progressive evolution of the Equidae. 

Thus there is a prolonged time overlap between the deposits of the 

Bighorn and those of Wind River. (See fig. 1, p. 23.)

" Am. Jour. Sci. May, 1907, 4th ser., vol. 23, pp. 35G-3G4.
42 CENOZOIC MAMMAL HORIZONS

- III. THIRD FATJNAL PHASE.

Absence of fresh Eurasiatic or northern migration Continuation of similar environmental conditions Descendants of the archaic and modernized mammals slowly evolving and competing with one another during 

the lower and middle Eocene Gradual elimination of the archaic mam- 

 mals Gradual divergence from the fauna of western Europe, and little 

. evidence of faunal interchange Establishment of North American 

Ungulata-Artiodactyla.

First, as to progressive divergence from Europe, it appears that by 

the middle and upper Eocene stage there were 13 non-European 

families of mammals in America and 11 non-American families of 

mammals in Europe, as against 4 European-American families common to the two regions. This independent and divergent evolution 

was not sufficiently emphasized until suggested by the writer in 

1899.a It points to the existence of prolonged geographic or climatic 

barriers between the two continents.

Second, as to the continuously uniform conditions in the Mountain 

Region, Matthew has especially called attention to the prolonged 

uniformity of life, alike as to families, genera, and species, throughout 

the Wasatch, Wind River, Huerfano, and.lower Bridger depositions. 

To this uniformity may be added the Uintatherium zone of the 

Bridger and Uinta basins; in other words, the uniformity extended 

from the lower to the upper Eocene. The changes are those of modification and development rather than of breaks in the balance of nature 

by migration and extinction.

Our conclusions are as follows: (1) Environment: Uniform and 

favorable environmental conditions prevailed during this long period 

in the Mountain Region, with the competition and balance of nature 

somewhat in favor of the modernized families, all of which persisted, 

while 5 families of the archaic mammals disappeared. (2) Evolution:

Both the archaic (Cretaceous) and the modernized mammals increased in size and in variety; the changes are chiefly specific rather 

than generic. (3) Gains and losses: Two archaic families of Ungulata, 

Condylarthra-Phenacodontidge and Amblypoda-Coryphodontidas, appeared for the last time (Wind River); 1 new archaic family, the 

Amblypoda-Uintatheriidse, appeared (Wind River); 2 families of 

archaic Carnivora-Creodonta have disappeared (Wasatch), namely, 

Palaeonictidse, Arctocyonidae; 6 the progressive Carnivora-Miacidae 

are represented by 5 genera; 1 new family of Ungulata-Perissodactyla

aOsborn, H. F., Correlations between Tertiary mammal horizons of Europe and America, etc.: Ann. 

New York Acad. Sci., vol. 13, 1900, p. 18. "Fourth, the Ligurien is widely distinct faunally from the 

American upper Eocene or Uinta, with which it has been heretofore paralleled. At no period of the 

Tertiary were the Nearctic and Palaearctic faunae so widely separated. In fact, a much wider gap exists 

between western America and Europe in the upper Eocene than in the preceding lower and middle 

Eocene or in the succeeding lower Oligocene."

b Matthew considers that the Arctocyonidse should not be placed among the archaic mammals, but 

rather that they represent an early branch of the Pro-Carnivore.
OF WESTERN NORTH AMERICA. 43

appeared (Wind River), namely, the Titanotheriidse, possibly entering 

from the Great Plains Region to the east; 1 new family related to the 

Edentata-Dasypoda, or armadillos, appeared (Bridger), probably 

from the southern Great Plains Region and originally of South 

American origin before the Cretaceous land connection was interrupted.

LOWER TO MIDDLE EOCENE (EUROPE, ETAGES YPRESIEN, LTJTETIEN

INFERIEUR).

4. WIND RIVER FORMATION;« LAMBDOTHERITJM AND BATHYOPSIS ZONES.

(Figs. 1-2, 5;'PL I.) 

IIOMOTAXIS.

North America. 1, Wind River formation, Hay den, of northern 

Wyoming (1,200-1,400 feet). 2, Upper half of the Wasatch of the 

Bighorn Basin. 3, Lower part of Huerfano formation, Hills, of 

Colorado (200? feet).

Europe (provisional). The lower part of the Wind River is partly 

equivalent to the Ypr6sien of France. The upper part of the Wind 

River is approximately equivalent to the Lute"tien inf6rieur of France.

FAUNA. b

The mammals of the Wind River deposition are less fully known 

than those of either the Wasatch or the Bridger. So far as these 

three faunae can be separated at present, the lower Wind River presents closer affinities to the Wasatch, whife the upper Wind River 

presents closer affinities to the Bridger. The balance of life between 

the archaic and the modernized mammals continues to be nearly 

even.

. Summary of genera.

Archaic or Cretaceous mammals.................................. 17

Modernized or Tertiary mammals................................. 17

34

Faunal sequence to the Wasatch. Partial faunal continuity with, 

and partial sequence in time to, the Wasatch is sustained (1) by the 

presence of 19 genera in common with the Wasatch, (2) by the rarity 

or absence of a few Wasatch animals, (3) by the occurrence of more 

advanced (or post-Wasatch) stages of evolution in a large number 

of descendants of animals which persist from the Wasatch, (4) by

"This section has been revised by Prof. F. B. Loomis, the most recent explorer of this basin.

b Loomis, F. B., Origin ot the Wasatch deposits: Am. Jour. Sci., May, 1907,4th ser.. vol. 23, pp. 350-364. 

Cope, E.D., The badlands of the Wind River and their fauna: Am. Naturalist, vol. 14,1880, pp. 745-748. 

See Appendix, p. 91.
44 MAMMAL HORIZONS

the significant fact that some of the more advanced stages occur in 

the base of the Wind River deposition, (5) by the introduction of 

true primitive Dinocerata or uintatheres, of primitive titanotheres, 

of new Primates, which are not found in the Wasatch, and of more 

highly specialized Tseniodonta (Stylinodon).

The writer's conclusions at present are (1) that the base of the 

Wind River, or Wind River A, began to be deposited during the 

upper stage of the Wasatch deposition of the Bighorn Basin (see p. 41),

Sathyopsis 

zone

Levels 

unrecorded

Eotltanops

(Palaeosyops)

borealls

Bathyopsis 

Tr/'temnodon

Coryphodon 

Bathyopsis 

Phenacodus 

Eohippus

Larnbdotherium, Lambdotherium 

zone

Hyopsoofus

Sciuravus 

Pelycodus

FIG. 5. Columnar section of the Wind River basin, based on the descriptions of Hayden and Loomis. 

The horizontal banding of the red and greenish-gray beds in Wind River B is very regular. The 

occurrence of Eotitanops and Bathyopsis in the upper Wind River is not certainly recorded.

and was thus contemporaneous with most of the upper fossil-bearing 

strata of the Bighorn Basin Wasatch; (2) that positive evidence of 

an overlap may be derived from the study of the faunae; (3) that 

the Lambdotherium zone occurs in each.

Geologic divisions. Hayden's exploration of 1859-60, as .reported 

in 1869," afforded materials for the first complete section we have 

of the Wind River Tertiaries. His "lower division," of 400 to 500

« Geol. Kept. Explor. Yellowstone and Missouri Rivers, by F. V. Hayden, assistant [to Col. William 

F. Raynolds, U. S. Engineers], Washington, 1869.
OF WESTERN NORTH AMERICA. 45

feet, which we may designate Wind River A, is largely fossiliferous 

and has yielded most of the important forms found in successive 

explorations by Wortman® (1891), Granger (1905), and Loomis 6 

(1907). Hayden assigned 1,200 feet to an "upper division," which 

we may designate Wind River B. This is now believed to contain 

fossils of a higher type, although the field records are not quite 

clear and fossils are scarce.

Preliminary faunal divisions. (A) Wind River, lower .500 feet, 

red beds. Lambdotherium zone. Contains CorypTiodon, Phenacodus, 

Eoliippus, Lambdotherium, etc. (B) Wind River, upper 800 feet. 

Batliyopsis zone. Contains Coryphodon, PJienacodus, also Bathyo'psis 

Pal&osyops borealis ( = Eotitanops).

The B stage approximates the middle Eocene, or Lute'tieii inferieur 

of France (Argenton, the older Lissieu and older Egerkingeii fissureformation faunae), and the Bracklesham of England.

General faunal characters of the Wind River. Since the faunal 

levels which undoubtedly distinguish Wind River A and B have not 

yet been clearly separated, we must consider the fauna chiefly as 

found on the lower levels, or red beds.' First it must be made clear 

that the Wind River, as compared with either the Wasatch or the 

Bridger, is a relatively barren formation and has not been so fully 

explored.

Archaic or Cretaceous fauna: Of the ancient fauna the Creodonta 

are represented by 4 families, the members of which are incompletely known. Of these the genera (a) liapalodectes and Pachysena 

(Mesonychidse), (&) Tritemnodon (Hyaenodontidae), and Oxys&na, 

(Oxyasnidae) are somewhat more advanced than W asatch forms; (c) 

Limnocyon, a primitive, and Patriofelis, a specialized member of the 

Oxyamidae, appear for the first time, animals which are very characteristic of the Bridger; (d) Anacodon represents the Arctocyonidse.

Among the Tillodontia the Wasatch genus EstJionyx persists, and 

among Tseniodonta (Edentata?) the Bridger genus Stylinodon first 

appears. The Insectivora are undoubtedly represented in Palsdctops (Leptictidas), Palseosinopa (Pantolestidse), and possibly also by 

several species of Ilyopsodus, all in more advanced evolution stages 

than those in the Wasatch, but still distinct from the Bridger species. 

It is noteworthy that Hyopsodus attains its largest size at this time. 

The reported existence by Cope of Cheiroptera is an error.

The Condylarthra-Phenacodorrtidse diminish and disappear. The 

Amblypoda-Coryphodontidae also diminish and disappear, being 

replaced by the Amblypoda-Uintatheriidae. Of Carnivora-Creodonta, the family Arctocyonidae is represented by Ana'codon (vide

a Wortman, ,i. L. , -Bull. Am. Mus. Nat. Hist., vol. 4, 1S92, pp. 136-144. 

l> Loomis, F. B., Am. Jour. Sci., 4th ser., vol. 23, 1007, pp. 35G-3G4.
46 CENOZOIC MAMMAL HORIZONS

Loomis); the Palaeonictidae are represented by. doubtfully referred 

specimens in the Wind River and lower Huerfano; the 3 certainly 

surviving creodont families are the Mesonychidse, Oxyaenidae, and 

Hyaenodontidae. The Edentata-Taeniodonta are represented by 

Stylinodon; the Tillodontia by Esihonyx. A supposed marsupial, 

Peratherium comstocki, is reported by Cope and Loomis.

Modernized fauna: Among the modernized forms the forest-living 

primates first deserve notice: (a) Of the animals of larger size the 

Notharctidse include Pelycodus, surviving from the Wasatch and continued into the lower Bridger; also Notharctus, a monkey very plentiful in the Bridger, now appearing for the first time; (&) the specialized Anaptomorphidae recur; (c) the doubtful primates Microsyopidse 

are also found.

The Rodentia are represented by the rather abundant Paramys and 

somewhat more rare Sciuravus. Among Insectivora, 3 families are 

known, namely, Leptictidse (Palsdctops), and the recently referred 

families Hyopsodontidae and Pantolestidae. The pro-Carnivora: 

Miacidae, now become more diversified, including the genera Didymictis, Vulpavus, and Miacis, all found in the Wasatch, which recur 

here in slightly larger and more progressive forms. These animals 

resemble the Canielae in dental structure and the Procyonidas in other 

points. The Bridger genera Viverravus and Oodectes appear here for 

the first time.

Of modernized Ungulata-Perissodactyla there are now 4 families. 

It is noteworthy that all are represented by light-limbed slenderfooted forms, pointing to rather dry-land conditions in this region 

at the time, (a) The Equidae are represented by the persisting 

Wasatch forms still known as Eohippus because a rudimentary fifth 

digit still persists in the pes and there is little advance in dentition. 

(6) Members of the Tapiridse have not been.found, but they undoubtedly existed, (c) The Lophiodontidse are represented by 

Heptodon. (d) The newly appearing Titanotheriidae are represented 

by 2 genera and 3 species.

The distinctive forms of titanotheres found in the Wind River are:

Lower part of Wind River, Lambdotherium popoagicum, of about the height of a water

chevrotain (Dorcatherium aquaticum). 

?Upper part of Wind River, Eotitanops borealis, of about the height of a wart-hog

(Phacochcsrus africanus). 

?Upper part of Wind River, Eotitanops brownianus, of about the height of a young

PigOf these animals the Lambdotherium occurs plentifully only in the 

upper Wasatch deposits, in the lower part of the Wind River, and in 

the Huerfano formation of southern Colorado. Nothing at present is 

known in the Wasatch which could stand ancestral to it, nor is any
OF WESTERN NORTH AMERICA. 47

Briclger genus known which could be directly descended from the 

specie§ L. popoagicum.

Of Ungulata-Artiodactyla Trigonolestes survives from the Wasatch.

WIND RIVER A; LAMBDOTHERIUM ZONE.

Period of lower deposition. Wortman® concluded on his second 

visit (1891) that the lower Wind River is absolutely distinct from 

the Wasatch of the Bighorn Basin and belongs to a succeeding deposition. He supposed that the Wind River country was above water 

during the laying down of the Wasatch sediments, and that some 

time after the close of the Wasatch a lake was formed on the site of 

the present Wind River basin. ' Loomis 6 (1907) regards the Wind 

River formation as epicontinental, fluviatile, and flood-plain, like the 

Wasatch, and slightly subsequent in the beginning of its deposition.

General characters. A total thickness of 400 to 500 feet near the 

sources of Wind River. Readily distinguished geologically by horizontally alternating bands of bright-red and gray fossil-bearing shales 

and sandstones containing Coryphodon, turtles (Trionyx), crocodiles 

(Crocodilus) , Lacertilia-Anguidae (Glyptosaurus), etc.. The conglomerates, indicating rapid stream or river invasions, are barren. The 

writer is indebted to Professor Loomis for the section (fig. 5, p. 44) 

and for Ins observations on stratigraphic distribution. .

Fauna. The chief part of the Wind River fauna listed above is 

from these red beds. In the lower red beds are found Coryphodon, 

Eoliippus, Lambdotherium, and several species of Hyopsodus; among 

primates, Nofharctus and Pelycodus. The American Museum collections of 1905, nearly all from the red beds, exhibit a closer degree of 

affinity to those of the upper Wasatch than is found in specimens 

from the upper beds. The Amherst collections include from these 

beds Batliyopsis, the earliest known member of the Dinocerata.

WIND RIVER B; BATHYOPSIS ZONE.

Penod of upper deposition. The upper levels, or Wind River B, 

are naturally to be compared with Bridger A, but unfortunately too 

few fossils have as yet been found to afford such a basis of correlation.

Hayden (1869) described these beds as consisting of 800 to 900 feet 

of ferruginous, coarse-grained sandstones, alternations of sandstones 

and marls, light sandstones, friable sandstones, and indurated marls. 

They are probably in large part of volcanic-dust origin. Some of 

these strata indicate great disturbances in the water during their

a Wortman, J. L., Fossil mammals of the Wasatch and Wind River beds: Bull. Am. Mus. Nat. Hist., 

vol. 4, 1892, pp. 143-144. 

b Loomis F. B , Origin of the Wasatch deposits: Am. Jour. Sci., 4th ser., vol. 23,1907, pp. 356-364.
48 CENOZOIC MAMMAL HORIZONS

deposition. Altogether the conditions were unfavorable, perhaps 

prohibitive, for the deposition of fossils.

Fauna. Although not certainly recorded, it appears probable that 

Wind River B contains Eotitcmo'ps lorealis, the second known stage 

in the evolution of the Titanotheriidse, the first known stage being 

Lambdotherium primsevum Loomis of Wind River A.

4a. HTJERFANO FORMATION; LAMBDOTHERITJM AND * UINTATHEKIUM ZONES.

HOMOTAXIS.

North America. 1, Huerfano formation of Hills, 1888 (800-1,000 

feet, Wortman). 2, Wind River (Lambdotherium zone) in part.- 3, 

Lower part of Bridger formation.

The only middle Eocene deposit east of the Rocky Mountains is 

that of the Huerfano River basin of southern Colorado (see PL I), 

first described by Hills 0 in 1888, explored by the writer and Wortman in 1897, and described by the writer. 6 The basin opens into the 

plains immediately north of the famous Spanish Peaks. The sediments described below as marls, clays, shales, etc., will very probably 

prove to be of volcanic-dust origin.

The writer's present conclusion as to the age of this formation, is 

that it began during the Wind River and continued without a break 

into the period of the lower Bridger formation.

LOWER PART OF HUERFANO FORMATION; LAMBDOTHERIUM ZONE.

(Homotaxis, Wind River.)

Wortman explored the immediately underlying levels to the east 

of Gardner, previous explorations having been made to the north and 

west, and was surprised to find a fauna containing none of the forms 

characteristic of the Bridger level (as chiefly found by Hills), but 

distinguished as of Wind River age by the presence of Corypliodon, 

Lambdotherium, Oxysena, Trigonolestes, and other lower Eocene forms. 

Wortmanc says:

These beds of the lower division are indistinguishable, so far as their general appearance and lithological characters are concerned, from those of the upper level. The 

fossils occur apparently in a single stratum not exceeding 10 or 15 feet in thickness, 

and not more than 30 or 40 feet from the base of the formation. They underlie the 

beds of the upper division with perfect conformity, and' there is at present no means 

of determining exactly where the one ends and the other begins. * * * The exact 

locality from which the greater number of the fossils of the lower beds were obtained 

is Garcias Canyon, about 1£ miles south of Talpa or the mouth of Turkey Creek.

« Hills, R. C., 1888.

ft Osborn, H. F., The Huerfano Lake basin: Bull. Am. Mus. Nat. Hist., vol. 9, 1897, p. 251.

c Wortman, J. L., Geological and geographical sketch of the Bighorn Basin. In Osborn, H. F., and 

Wortman, J. L., Fossil mammals of the Wahsatch and Wind River beds: Bull. Am. Mus. Nat. Hist., 

vol. 4, 1892, pp. 135-144.
OF WESTERN NORTH AMERICA. 49

The fauna, as originally determined and subsequently (February, 

1906) reexamined by Matthew from the very small American Museum 

collection, is as follows:

Lower Huerfano fauna and equivalents. 

[X=speeies represented; (X)=genus represented.]

Lower 

Huerfano.

V

y

Y

(?)

V

V

V

V

(i)

X

Wasatch.

( y>

y

y

(Y\

(V)

y

y

X

Wind 

River.

V

V

Y

V

X

Bridger.

( xl

X

The Eohippus is more advanced than anything in the Wasatch,. 

but distinctly more primitive than the most primitive Orohippus of 

the Bridger in our collections: The lower part of the Huerfano is, 

oil this showing, homotaxial with a portion of the Wind River.

UPPER PART OF HUERFANO FORMATION; ?UINTATHERIUM ZONE.

(Homotaxis, lower (?) Bridger.)

West of Huerfano Canyon the so-called variegated marls, clays, 

soft shales, and sands aggregate only 800 to 1,000 feet in thickness, 

are nearly horizontal in position, and constitute the "upper series" 

of the typical Huerfano lake deposits, of Hills. To the west of 

Gardner all the mammal remains were found in these sands, clays, 

and marls, varying from red, purple, gray, or green to yellow or whitish 

in color, the upper arenaceous clays containing the richest deposits. 

These deposits have not been examined lithologically; it is quite 

possible that they are largely composed of volcanic ash. Although 

the fossils are nowhere numerous, they are all of Bridger age, namely, 

Palxosyops, Hyrachyus, Tillotheriwn, and Glyptosaurus.

Upper Huerfano fuana and equivalents.

Upper 

Huerfano.

y

y

y

y

fy\

Wasatch

X

Wind 

River.

y

y

Bridger.

v

v

(y\

a The Amblypoda are represented by a tibia of small size which may have belonged to Uintatherium. 

56092 Bull. 361 09 4
50 CENOZOIC MAMMAL HOKIZONS

It is clear that these beds must be referred to the Bridger, not to 

the Wind River. The Paramys compares most nearly with lower 

Bridger species, but is too incomplete to settle its position without 

very careful comparisons. There does not appear to be anything 

else to indicate whether these beds are equivalent to lower or to 

upper Bridger. The Patriofelis is a very much smaller species than 

P. ulta of the lower Bridger or P. ferox of the upper Bridger. The 

Tillofherium is a characteristic Bridger animal.

MIDDLE EOCENE EUROPE, ETAGES LUTETIEN SUPERIEUR,

BARTONIEN).

5. BRIDGER FORMATION; OROHIPPTJS AND TJINTATHERIUM ZONES.

(Figs. 1, 2, 6, PI. I.) 

HOMOTAXIS.

North America. 1, Bridger formation of western Wyoming 

(1,850 feet), including levels A, B, C, D, E. 2, Upper part of Huerfano formation of Colorado, 3, Lower beds, or Uintatlierium zone, 

in Uinta and Washakie basins of northern Utah (800 feet) in part. 

4, Clarno formation of Oregon, Merriam; homotaxis provisional.

Europe, provisional Jiomotaxis. Lower part of the Bridger approximately equivalent to Lutetien superieur, represented by the Calcaire grossier (Paris basin), Issel, Buchsweiler, and later fissure 

deposits of Lissieu and Egerkingen. Upper part of the Bridger 

approximately equivalent to Bartonien (Calcaire de Saint Ouen, 

Ores de Cesse'ras) in part.

CHIEF CHARACTERS OF THE FAUNA.0

The whole vertebrate fauna, reptilian and mammalian, of this

period is better known than that of any of the other Eocene phases. 

The mammalian summary is as follows:

Summary of genera.

Archaic Cretaceous mammals...................................... 32

Modernized Tertiary mammals................................... 45

77

A marked numerical predominance, in the ratio of 4 to 3, of the 

modern over the archaic genera of mammals. A single South 

American mammal appears, the primitive armadillo Metacheiromys, 

related to the Dasypoda. Affinities with western Europe are very

a See Appendix, p. 91,
OF WESTERN NORTH AMERICA, 51

slight indeed. Independent evolution both of the surviving archaic 

and of the modern American lower Wasatch stock, with no evidence 

of fresh Eurasiatic migrations. Establishment of certain characteristically American families of mammals.

NONFOSSILIFEROUS Very barren

Umtstherlum 

(very abundant)

,.. . -, . Mesatirhinus 

l/mtatnerium Menteoceras

_ _ _ Palaeosyopa 

^^=-=^^=i (very abundant)

Fui. 6. Columnar section of the Bridger formation, Henrys Fork, western Wyoming. After studies

by Matthew and Granger, 1902.

Preliminary faunal divisions. The Bridger has been separated 

(Matthew, Granger) into four distinct faunal levels, A-D, marked 

by distinct specific stages and generic stages, also by the appearance 

and disappearance of certain types.

1, Lower part of Bridger, levels A-B. Orohippus zone. Characterized by absence of Uintaiherium; presence of Tillodontia,
52 CENOZOIC MAMMAL HOEIZONS

i

Trogosus (?Anchippodus a); Perissodactyla-Equidae, OroTiippus; Car- j 

nivora, Ob'dectes, Vulpavus. j

2, Upper part of Bridger, levels C-D. Uintatherium zone. Char- j 

acterized by presence of Uintafherium; Perissodactyla-Titanotheriidae, 

Mesatirliinus megarhinus; Tillodontia, Tillotherium; and lower beds, 

or Uintafherium zone, of Uinta and Washakie basins, ?upper part 

of Huerfano, Colorado. j

The fauna of these levels is very fully known and the levels are j 

sharply distinguishable. . j

The archaic fauna b includes mostly mammals of larger size. As 

in the Wind River, the Carnivora-Creodonta include 3 families 

Oxysenidse, Hyaenodontidae, and Mesonychidas predaceous types 

rapidly increasing in size and power. Aberrant -Tillodontia, 2 j 

genera (Trogosus, Tillotherium), their last appearance. EdentataTaeniodonta, 1 genus (Stylinpdori), scarce animals, also their last j 

appearance. Of Ungulata-Amblypoda, the Uintatheriidae or giant j 

Dinocerata suddenly appear in the upper Bridger, possibly from the ? 

Great Plains Region. ;!

The modern fauna includes mammals of small and intermediate " 

size for the most part. The pro-Carnivora, Miacidas, rapidly multiply j 

and diversify into 8 genera, 20 species, analogous to the modern \ 

Canidae in tooth structure,0 and probably drive out the smaller \ 

Carnivora-Creodonta. Primates, 2-3 families, (a) Notharctidae, 

(&) Anaptomorphidae, (c) ?Microsyopidae. Rodentia more numerous 

and diversified; the family relationships are uncertain, but include 

(a) with sciuroid teeth, 2 genera; (6) with arctomyoid teeth, 3 

genera. Insectivora more diversified, 4-6 families, including animals 

analogous to if not actually related to Erinaceidae, Talpidae, Soricidse, 

Centetidae, also the aberrant Pantolestidae, ?Hyopsodontidae, and 

?Leptictidae. Related' to the Edentata-D.asypoda, Metacheiromys, 

2 species. Ungulata-Perissodactyla flourishing, 5 families, namely: 

(a) Equidae numerous, 9 species; (1)) Lophiodontidae, 3 genera; (c) 

Tapiridae, 1 genus; (d) Titanotheriidae, 4 genera; first' appearance 

of the (e) Rhinocerotoidea-Hyracodontidae, 3 genera. Ungulata- "> 

Artiodactyla still of small size, but diversified into 7 genera, includ- ;.: 

ing primitive Selenodonta and Bunodonta. j

aAnchippodus Leidy is typically from New Jersey, Shark River, Monmouth County. See Proc. j 

Acad. Nat. Sci. Philadelphia, October, 1868, p, 232.

* See Appendix, p. 91.

c Matthew observes, as to the affinities of these anirnals: "They'do not make any approach to the ; 

modern Canidse except for the dentition, which shows three groups viverroid, cynoid, cercoleptoid. j 

The skeleton structure varies from cercoleptoid to viverroid. The skull structure in the viverroid ,1 

group is much more musteloid." 1
OF WESTERN NORTH AMERICA. 53

MIDDLE TO UPPER EOCENE (EUROPE, ETA'GE BARTONIEN).

6. LATEE EOCENE DEPOSITS OF WASHAKIE BASIN; TJINTATHEKIUM AND EOBASILETTS ZONES.

(Figs. 1, 2, 7; PI, I.) 

HOMOTAXIS.

North America. 1, Uintatherium, zone, equivalent to the upper part 

of the Bridger formation and to the Uintatherium zone of Uinta 

Basin. 2 ; Eobasileus zone, equivalent to the Eobasileus zone of 

Uinta Basin. ?3, Deposits on Sage Creek, Montana.

Europe. Bartonien of France.

HISTORY.

The Washakie Basin is a distinct area, with deposits mainly of 

volcanic ash, in which Hayden (1867-1869) first used Washakie as 

a group name comprising the 

lower and middle Eocene section. Subsequently he inclined 

to the .belief a "that the upper 

series is either an extension eastward of the Bridger group or 

synchronous with it." It was 

similarly referred to by King as 

the Bridger group of the Washakie Basin. 6 This upper series 

has sometimes been referred to 

in paleontologic literature as the 

"Washakie formation."

Doli'chorhinua 

Amynodon 

Achaenodon 

Eobasileus

Manteoceras 

Mesatirhinus 

Uintatherium

FAUNA. c

1'iG. 7. Preliminary columnar section of the later 

Eocene deposits of Washakie Basin, Wyoming. 

The upper or Eobasileus zone is now (1908) determined as thicker than the lower division. The mammalian fauna of this 

stage, which has long been recognized (Osborn/ 1881) as in general 

intermediate between the Bridger and the Uinta, is sparsely known. 

The American Museum expedition (Osborn, Granger) of 1906 very 

precisely fixed its age as overlapping the summit of the Bridger and 

the Uintatherium and Eobasileus zones of the Uinta Basin.

Faunal divisions. (A) Uintatherium zone. Brown beds (250 feet) 

containing Uintatherium. Among Perissodactyla, Mesatirhinus megaoPrel. Kept. U. S. Geol. Survey Terr., 1871, p. 73.

fcKing, Clarence, U. S. Geol. Explor. 40th Par., Systematic geology, 1878, .p. 390.

c See Appendix, p. 91.

<i A memoir upon Loxolophodon and Uintatherium: Contr. E. M. Mus. Geol. Archaeol. Princeton, 

vol. 1, No. 1, 1881, pp. 1-14. .

McMaster, John Bach, Stratigraphical report upon the Bridger beds in the Washakie Basin, 

Wyoming Territory, accompanied by profiles of three sections, in Osborn, II. F., A memoir, etc., as 

above.
54 CEN026IC MAMMAL HORIZONS

rliinus&nd Manteoceras indicate equivalence to upper Bridger (C-D). 

(B) Eolasileus zone. Gray and green beds (250 feet), Haystack 

Mountain, containing Eolasileus a (LoxolopTiodon}; PerissodactylaAmynodontidse; Titanotheriidse, Dolichorhinus cornutus; Artiodactyl a-Elo theriidae.

The lower (A) brown beds are very extensively distributed and. contain many of the same species as the upper Bridger (C-D). The 

upper (B) gray and green beds, probably composed largely of volcanic 

ash, are chiefly restricted to the great butte known as Haystack 

Mountain and its outlying badlands; the fauna is largely new and 

marks a very distinct progressive stage.

The new fauna of the Eolasileus zone. The archaic fauna is distinguished by the final evolution of the Ungulata-Amblypoda into large, 

specialized Dinocerata. Carnivora-Creodonta certainly include Oxyaenidae and Mesonychidse; the Hyaenodontidae are represented by 

Sinopa.

In regard to the modern fauna the most signal fact is the first 

appearance among the Perissodactyla-Rhinocerotoidea of the new 

family (a) Amynodontidae. The (I) Hyracodonticlse continue from the 

Bridger; among (c) Titano theriidae, Palseosyops disappears; (d) Lophiodontidse-Helaletinae, (e) Tapiridse, and (/) Equidge persist. Artiodactyla are small but more diversified. Rodentia-Ischyromyidae. ProCarnivora-Miacidae. Large elotheres, Acksenodon, occur.

UPPER EOCENE (EUROPE, ETAGES BARTONIEN IN.PART, LUDIEN

(LIGURIEN) IN PART).

7. LATER EOCENE DEPOSITS OF TJINTA BASIN; TTINTATHERIUM, EOBASILEUS, AND

DIPLACODON ZONES.

(Figs. 1, 2, 8; PI. I.)

IIOMOTAXIS.

North America. 1, Lower 800 feet, Uintatherium zone, provisionally equivalent to upper part of the Bridger formation and equivalent 

beds in Washakie Basin. 2, Middle 350 feet, Eolasileus zone, equivalent to upper zone of Washakie Basin. 3, Upper 600 feet, Diplacodon 

zone, equals Uinta formation ("true Uinta"), 6 approaching if not 

equivalent to the lowermost levels of the White River Oligocene, i. e., 

lower Titanotherium zone or Chadron formation.

Europe. Homotaxis is now very difficult owing to the absolute 

dissimilarity of the European and North American faunae in these

« The name Loxolophodon, commonly applied by Cope and others to the Dinocerata of this stage, is 

preoccupied for a Wasatch coryphodont, Loxolophodontsemicinctus Cope. Tinoceras Marsh is equally 

inapplicable because first applied to a Bridger uintathere.

b The Uinta formation as first noticed by Marsh (Introduction and succession of vertebrate life in 

America: Am. Jour. Sci., 3d ser., vol. 14, 1877, p. 337) included only the highest Eocene deposits, 

Diplacodon zone (horizon C, the "true or upper Uinta" of King and other writers), to which beds 

the name is here restricted.
OF WESTERN NORTH AMERICA. 55

stages; the climax of separation between the North American and 

western European faunae is reached at this stage.

FAUNA.0

It is very important to note, as to the possible lower Oligocene age 

of the Uinta formation (Diplacodon zone): (1) That in the Bartonien 

of France, which is reckoned as upper Eocene, but not the highest 

stage, there appear the families Artiodactyla-Anthracotheriidse and

c

600'

B 350'

A 800'

| UINTA

CENE OFUINTA BASIN

LATER EO

"r. .^TTrSV*- Artiodactyla and chief collection 

 '' ' MV-=>a jJ4J ofU/nta mammals(small)

:vx^r\v.:.;;;-:-:-::.v. :.:.:.V:v/.i ^_ Doiic

v.v.Sa n dsto n es-;-;;.; v| c/?/e/

Sllllliilll

horhinus cornutus, 

fosslliferous level

Amynodon 

lens 

Metarhinus.

> 

 < - Chief fosslliferous level

Metarhinus

llllffilliSii

PIG. 8. Columnar section of the Uinta formation, northern Utah. In A and B the diagram does not 

properly represent the irregular nature of the so-called sandstones and clays, which are probably in 

part coarser and finer volcanic-dust deposits. Modified from notes by 0. A. Peterson, 1894. Faunistic studies of Osborn.

Perissodactyla-Chalicotheriiclse; (2) that in the Ludien, which is reckoned as uppermost Eocene, or the highest stage, there appear the 

families Marsupialia-Didelphyidae and Rodentia-Sciuridae;. (3) that 

none of these four families are known to occur in deposits older than 

the lower Oligocene Plains formation of North America. We are therefore not justified, from our present knowledge, in transferring the Uinta 

formation (Diplacodon zone) to the lower Oligocene, as some authors 

(Scott) propose.

a See Appendix, p. 91.
56 CENOZOIC MAMMAL HOEIZONS

Faunistic separation from western Europe in the upper Eocene.

Order.

Amblypoda. .......................................................

Primates. . ........................................................

Cheiroptera ........................................................

Families 

peculiar to 

Europe.

(?)

2

1

0

6

1

1

n

Families 

common 

to western 

Europe 

and North 

America.

(?)

1

0

i

0

2

(?)

4

Families 

peculiar to 

North 

America.

1

(?)

9

2

1

0

4

3

(?)

13

Thus in the later Eocene of the Mountain Region (TJintaffierium, 

Eobasileus, and Diplacodon zones) there are only 4 or 5 families in 

common with Europe out of a total of 28 to 30, whereas in the succeeding Oligocene Mountain and Plains regions (see p. 59) there are 21 

families in common with Europe out of a total of 48.

The entire -Uinta Basin deposition, as first fully explored by the 

American Museum expedition under Peterson, 0 overlaps in time 

both the upper Bridger and the entire "Washakie" deposition; thus it 

begins (Osborn) contemporaneously with the uppermost portion of the 

Bridger, is equivalent to the entire "Washakie/' and then continues 

after the close of the "Washakie" into the Uinta (Diplacodon zone, 

"true or upper Uinta")- 6 Its sparsely known mammalian fauna 0 

is as follows:

Summary of genera.

Archaic Cretaceous mammals. ....................................... 6

Modern or Tertiary mammals...................................... 27

33

The term Uinta formation (Marsh and-King) is confined to the 

upper beds, or Diplacodon zone ("true Uinta").

PROVISIONAL FAUNAL LEVELS.

C. Uinta formation, 600 feet. Diplacodon zone, Distinguished

by absence of Dinocerata; presence of Canidse.

B. Middle beds of Uinta Basin, later Eocene, 350 feet. . Eobasileus 

zone. Contains among Amblypoda-Dinocerata, Eobasileus (generic

"Osborn, H. F., Fossil mammals of the Uinta Basin, etc.: Bull. Am. Mus. Nat. Hist., vol. 7, 1895, 

pp. 71-105.

& This "true Uinta" fauna was that which was first determined and described by Marsh in 1870. 

The underlying Uintatherium and Eobasileus faunae were first discovered by Peterson in 1894 and 

described by the writer.

« Scott, W. B., and Osborn, H. F., The Mammalia of the Uinta formation: Trans. Am. Philos. Soc., 

n. s., vol. 16,1889, pp. 461-572.
OF WESTERN NORTH AMERICA. 57

reference uncertain); among Perissodactyla-Titanotheriidae, Dolichorhirius cornutus. Creodonta-Mesonychidae (last appearance). Closely 

equivalent to upper part of "Washakie" (B).

A. Lower beds of Uinta Basin, later Eocene, 800 feet, brown beds. 

? TJintatherium zone, approximately equivalent to upper part of the 

Bridger (C-D) and to corresponding beds in Washakie Basin (A).

Of archaic mammals the Carnivora-Creodonta include 2 families,. 

Mesonychidse (last appearance) and Oxyaenidae (last appearance); 

the Hyaenodontidae, if existent, have not been discovered. The 

Eobasileus zone contains the last of the Amblypoda-Uintatheriidae. 

Of. modern mammals (Uinta) the Primates are little known as yet. 

Among Rodentia 2 families, (a) Ischyromyidse (Paramys, Pseudotomus], (1)) Heteromyidse (Protoptychus). Among Pro-Carnivora, 

Miacid.se, also true Carnivora a ( Cynodictis). Of Ungulata-Perissodactyla, 6 families: (a) Titanotheriidse, horned animals of much 

greater size, especially increasing after the extinction of the huge 

Dinocerata, (6) Equidae, (c) Lophiodontidae (still to be discovered), 

(d) Tapiridae, (e) Hyracodontidse, (/) Amynodontidse. No true 

Rhinocerotidse. Ungulata-Artiodactyla now assume the five divisions or families which are found in the American Oligocene, namely: 

(a) Elotheriidse-Achsenodontinse, mammals of large size; (&) liomacodontidse (Dichobunidae ?); (c) Oreodontidae, North America only; 

(d) Hypertragulidae, North America only; (e) Camelidse, the first 

definite recognition of this family, North America exclusively until 

the Pliocene. The Uinta selenodonts b are all brachyodont and 

much alike in dentition; they are much less abundant than in the 

lower- Oligocene.

OLIGOCENE.

IV. FOURTH FATJNAL PHASE.

Second modernization First knowledge of the Great Plains fauna 

Absence of all archaic mammals except Hyeenodontidee Reestablishment of faunal resemblance with western Europe, followed by a long 

period of independent evolution and partial extinction of the same 

fauna to the close of the lower Miocene. ,

Environment; dry-land conditions in the Great Plains. In addition 

to the geologic and faunistic evidence above cited we find collateral 

evidence from herpetology. The Testudinata, as analyzed by Dr. 

0. P, Hay,c furnish important proofs of prevailing dry-land conditions

« A rather arbitrary distinction, founded on the union of the scapholunar bones, which first occurs 

in certain Bridger species of the Miacidai; the union is exceptional in the Bridger, presumably common 

in the Uinta, and universal in the White River. More essential distinctions are the small size of the 

brain and the absence of tympanic bullaj.

6 Scott, W. B., The selenodont artiodactyls of the Uinta Eocene: Trails. Wagner Free Inst. Sci., 

Philadelphia, vol. 0,1899, pp. ix-xiii, 1-121.

c In. his monograph on the fossil turtles of North America, published by the Carnegie Institution.
58 CENOZOIC MAMMAL HOEIZONS

in the Great Plains. How long previously these conditions had set 

in it is impossible to say. In the entire Oligocene and Miocene beds 

thus far only 6 species of water-living turtles have been described or 

recorded, and these are probably from river-channel sandstones, as 

compared with a very much larger number of land-living tortoises.

The details are as follows: (1) In the White River group (lower 

Oligocene) there occur 8 species of the Testudinidse, including one of 

the land tortoise Stylemys; one species of Testudo, T. Irontops Marsh, 

belongs to the Chadron formation, or Titanotherium zone; all of these 

are land tortoises, mostly found in Colorado. Of water-living forms 

the White River group of South Dakota has furnished one species of 

the Emydidae, river turtles, and one of the Dermatemydidae, a small 

family related to the Chelydridae and now confined to Central America. 

(2) In the middle part of the John Day formation (upper Oligocene, 

Mountain Region) there are 3 species of Stylemys, land tortoises. (3) 

In the Deep River sequence (middle Miocene, Mountain Region) 

occurs a single species of Testudo; from the Mascall formation of 

Oregon there is known a species of Clemmys, a genus now living in 

America and Asia. From the deposits on Pawnee Creek, Colorado, 

come 2 large species of Testudo. (4) The "Loup Fork beds" (upper 

Miocene, Plains Region) furnish 7 species of Testudo, approaching in 

size the great tortoises of the Galapagos Islands. (5) From the Rattlesnake formation of Oregon (Pliocene) occurs a species of Clemmys, 

a land tortoise.

Modernization in North America. A second American modernization, as remarkable as the first or Wasatch modernization, is shown 

by the first appearance of 16 families of mammals which have not as 

yet been certainly recognized in the Mountain Eocene basins, namely, 

6 existing families of Rodentia, 4 existing families of Carnivora, 4

existing families of Insectivora, 1 existing family of Perissodactyla, 

1 now extinct European family of Artiodactyla.

Modernization in Europe. A very similar modernization occurred 

in western Europe.* In the Ludien ( = lower Oligocene, Lapparent, 

uppermost Eocene, Deperet), Sannoisien, and Stampien ( = lower Oligocene) 17 modern or still existing families which have not been 

found in earlier geologic stages appear for the first time. Of these 

new families, 6 appeared simultaneously in North America.

a This generalization is chiefly based upon the faunal lists of Dep6ret (see footnote, p. 9).
OF WESTERK NORTH AMERICA. 59

Faunistic reunion with western Europe in the Oliyocene.

Order.

Western 

European 

families 

not found 

in North 

American 

Oligocene.

1

5

1

0

0

»3

5

1

10

Families 

common to 

western Europe and 

North America by contemporaneous or 

previous 

migration.

0

4

. 3

1

1

3

2

<>7

2L

North 

American 

families 

not found 

in western 

European 

Oligocene.

0

3

2

0

0

1

4

1

n

« Subfamily.

l> The Titanotherlidas found in central Europe are included in this number. Dr. II. G. Stehlin (letter, 

April 15, 1907?) regards the geologic level of these animals as Oligocene. They closely resemble certain of our titanothercs.

Thus (1) the faunal community with western Europe becomes 

much closer than in the upper Eocene (see p. 56); (2) it is important 

to note that many American lower Oligocene types are represented 

by more primitive forms of European upper Eocene types and partly 

of north African types, namely, Hysenodon, Hyopotamus, Elotlierium, 

and Suoidea-Dicotylidse; (3) the strongest community is among the 

Perissodaetyla, with 7 families out of 9 in common; (4) the least 

community is among the Artiodactyla, with only 2 families out of 11 

in common.

As above noted, this momentous faunal change in North America 

may be more apparent than real, because attributable to various 

causes: (1) Partly to the fact that this is our first glimpse of the 

western portion of the Great Plains fauna; (2) partly to fresh migration from the northerly or North American-Eurasiatic region. The 

apparent sharp distinctions of this phase from the Uinta faunal phase 

will probably be partly lessened when a fuller knowledge of the Uinta 

mammals shall have been gained.

There are many distinctive characters of this North American 

faunistic stage, as follows: (1) First appearance of MarsupialiaDidelphyidse and of Rhinocerotidse-Diceratheriinse; (2) sudden disappearance of all Primates, which do not again appear in North 

America; (3) continued evolution of certain of the North American 

families of mammals derived from the first modernization, 4-toed 

horses replaced by 3-toed horses, advanced evolution of American 

Eocene Rodentia (Paramys, Sciuravus), appearance of Eurasiatic 

Rodentia; (4) extinction of other modernized North American families, including especially 4 families of Perissodactyla, also, InsectivoraHyopsodontidae; (5) migration, probably from Eurasia, of some new
60 CEN020IC MAMMAL HORIZONS

families Perissodactyla-Chalicotheriidge, Artiodactyla-AnthracotheriidEe, Suoidea, Creodonta-HyaBnodontidse; (6) first appearance of 

Carnivora-Mustelidse, probably from the northern continental mass, 

also Canidse and Felidae-Machasrodontinse; (7) probable migration 

to Eurasia of some of the North American families, PerissodactylaTapiridae, Amynodontidse.

LOWER OLIGOCENE, WHITE RIVER GROUP OF HAYDEN (EUROPE, 

. ETAGE SANNOISIEN [TONGRIEN INFERIEUR]).

7. CHADRON FORMATION ; TITANOTHERIUM ZONE.

(Figs. 1, 9, 10; Pis. I-III.) 

HOMOTAXIS AND SYNONYMY.

North America. 1, Horizon A of Hay den and Leidy; lower part 

of the White River group; 2, Chadron formation, 200 feet, of Darton; 3, " Titanotherium beds" a of Leidy and Hayden, South Dakota; 

4, "Horsetail Creek beds" of Matthew,6 northeastern Colorado and 

western Nebraska; 5, Monument Creek formation (upper part) of 

Darton; 6, White River deposits along Pipestone Creek, Montana 

(Douglass, 1902); and 7, White River deposits along Swift Current 

Creek, Cypress Hills, British Columbia,0 etc.

Europe, provisional Jiomotaxis. Ludien, in part; Sannoisien (Tongrien inf erieur); Stampien (Tongrien superieur). 

 FAUN A. d

It is important to note again that four or more of the newly 

appearing families of mammals are represented in the upper Eocene 

of Europe. Our knowledge of the animals of this stage, which is at 

present considered lower Oligocene, is still rather limited except as to 

the Tltanotheriidse, which are very abundant and characteristic. In 

the White River beds at Pipestone Springs, Montana/ were first discovered (Douglass-0 the animals of smaller size or microfauna. In 

all the other deposits chiefly the larger animals are known.

a Hatcher, J. B., The Titanotherium beds: Am. Naturalist, Mar. 1,1893, pp. 204-221.

6 Matthew, W. D., Stratigraphy of the White River and Loup Fork formations: Bull. Am. Mus. 

Nat. Hist., vol.1, pt. 7,1901, pp. 355-374.

'Cope, E. D., The White River beds of Swift Current River, Northwest Territory (Geol. Oligocene 

White River): Am. Naturalist, Feb., 1885. Also Ann. Rept. Geol. and Nat. Hist. Survey Canada, 

vol. 1,1885 (1886), appendix to Article C, pp. 79-85.

d See Appendix, p. 91. .

Scott, W. B., and Osborn, H. F., Preliminary account of the fossil mammals from the White River 

formation contained in the Museum of Comparative Zoology: Bull. Mus. Comp. Zool. Harvard Coll., 

vol. 13,1887, pp. 151-171.

Osborn, H. F., and Wortman, J. L., Fossil mammals of the lower Miocene White River beds, coll. 

1892: Bull. Am. Mus. Nat. Hist., vol. 6, 1894, pp. 199-22S.

«Matthew, W,D., The fauna of the Titanolherium beds of Pipestone Springs, Montana: Bull. Am. 

Mus. Nat. Hist., vol. 19, 1903, pp. 197-226.

/Douglass, Earl, New vertebrates from the Montana Tertiary: Ann. Carnegie Mus., vol. 2, No. 2, 

1903, pp. 145-200. (White River stratigraphy.)
U. S. GEOLOGICAL SURVEY BULLETIN NO. 361 PL. II

Aruteree Brule 

formation formation

OLIGOCENE (CHADRON, BRULE) AND MIOCENE (ARIKAREE, HARRISON, ROSEBUD) EXPOSURES IN SOUTH DAKOTA, NORTHWESTERN NEBRASKA, AND

EASTERN WYOMING.

After Darton's survey, 1905, modified by observations of Matthew and Thomson (1906-7). For section A see fig. 14; for section B see fig. 12.
OF WESTERN NOETH AMEKICA. 61

The archaic mammals are now represented only by the true HyaBnodontime, which are probably of European and African origin. Among 

Marsupialia, Didelphyidae are somewhat doubfully recorded in this 

stage.

Of the modernized mammals, among Rodentia (a] Ischyromyidse, 

represented by Ischyromys; Paramys disappears or gives rise to Sciurus; and there first appear the modern (6) Leporidse, (c) Castoridse, 

(d) Sciuridse, and (e) Geomyidae. Of Insectivora the Leptictidae 

continue, as well as animals analogous in dentition to Centetes and 

Solenodon. The Carnivora are thoroughly modernized by the appearance of true Canidse (Cynodictis, Daplixnus], Mustelidse, and Felidae 

(MachsBrdciontinse). Eight families are known of Ungulata-Perissodactyla, including 6 Eocene families which survive from the upper 

Eocene, namely, (a) Equidse, (6) Tapiridse, (c) Amynodontidse, (d) 

Hyracodontidse, (e} Lophiodontidse, (/) Titanotheriidse,* which reach 

the climax of their evolution and suddenly disappear, ((/) the aberrant 

Perissodactyla-ChalicotheriidaB are first positively recognized, (Ji) the 

Rhinocerotidse, ancestors of Diceratlierium, and another subfamily 

(?Aceratheriinse) also first appear. Of Artiodactyla 6 families occur, 

as follows: Three previously known Eocene families,(a) Oreodontidae, 

(&) Camelidse, and (c) Hypertragulidse, continue; (d) the Dicotylidse 

first appear, either of American origin from the Great Plains or of 

Eurasiatic origin as a side branch of the Suoidea; (e) the Anthracotheriidie also first appear, probably by migration from Europe, and 

are represented by Hyopotamus in the Chadron formation; (/) the 

bunodont Achajnodontinse of the upper zones in the Washakie and 

Uinta basins are succeeded or replaced "by the Elotheriinse or Entelodontinse closely allied to the European Entelodon.

Monument Creek formation. The following description of this formation is taken from a paper by Darton published in 1906 : b

On the high divide between the Platte and Arkansas drainage basins, at the foot 

of the Rocky Mountains, there is an extensive deposit of conglomerates, sand, sandstone, gravel, and clay, known as the Monument Creek formation. It lies on the 

Laramie formation to the east and the Arapahoe formation to the west, and at Palmer 

Lake it abuts against the granite at the foot of the mountain. There are two members, 

a lower one of sands and plays and an upper one of conglomerate and sandstone. The 

latter caps numerous buttes and plateaus in the high region west and north of CaDian 

and north of Monument.

Fossil bones of Titanotherium have been discovered by the writer c and Mr. C. A. 

.Fisher in the upper member in the region north of Calhan and southwest of Elizabeth, 

which indicate that this portion of the formation is of Oligocene age. The lower 

member may be Oligocene, or perhaps Wasatch or Bridger, in age.

oOsborn, H. F., The four phyla of Oligoccne titanotheres: Bull. Am. Mus. Nat. Hist., vol. 16, 1902, 

pp. 91-109.

6 Darton, N. H., Geology and underground waters of the Arkansas Valley in eastern Colorado: Prof. 

Paper U. S. Geol. Survey No. 52, 1900.

« Darton, N. H., Age of Monument Creek formation: Am. Jour. Sci., 4th ser. vol. 20,1905, pp. 178-180.
62 CENOZOIC MAMMAL HORIZONS

MIDDLE OLIGOCENE (EUROPE, ETAGE STAMPIEN [TONGRIEN

SUPERIEUR]).

9. LOWEE PART OF BRULE CLAY (BARTON); OREODON ZONE AND "METAMYNODON SANDSTONES."

(Figs. 1,9, 10; Pis. I-III.) 

HOMOTAXIS AND SYNONYMY.

North America. I, Horizons B and C of Haycten and Leidy. 2, 

Oreodon zone of Leidy. 3, Lower Brule clay of Darton. a 4, " Metamynodon sandstones" of Wortman. 6 (1-4 all of South Dakota.) 5, 

"Cedar Creek beds" of Matthew,c northeastern Colorado. 6, Widespread similar exposures in southeastern Wyoming, South Dakota, 

and northwestern Nebraska. 7, Scattered exposures in western 

Montana.

Europe. Approximate homotaxis with the Stampien or Oligocene 

moyen of Europe is indicated by similar stages in the evolution 

of Artiodactyla-Anthracotheriidse . (Hyopotamus), of PerissodactylaAmynodontidae (e. g., Metamynodon, Cadurcotherium), of Tapiridse, of Rhinocerotidae, and of 

Chalicotheriidse. Also by the 

apparent disappearance in both 

countries of PerissodactylaAmynodontidse and CreodontaLeptauchenia 

clays"

sandstones " 

' Oreodon clays'"

Metamynodon 

sandstones"

Tttanother/um 

__ __ _ clays and 

=Ttfahotheriuni\zone sane/stones"

Hyeenodontidae 

Oreodon zone.

in the upper

FIG. 9. Diagrammatic section of the White River 

group. South Dakota. (Cf. PI. II.) Chiefly after 

Wortman, 1892.

FAUNA. 0

The rich mammalian fauna 

(more than 48 species being 

known in the big badlands of South Dakota alone) is distinguished 

negatively by the absence of Titanoiherium and positively by the 

presence of abundant oreodonts.

The important distinction was first made by Matthew e that the 

Brule clay, or Oreodon zone, of fine, still-water or eolian composition,

oDarton, N. H., Preliminary report on the geologjT and underground-water resources of the central 

Great Plains: Prof Paper U. S. Geol. Survey No. 32,190-5.

& Wortman, J. L , On the divisions of the White River or lower Miocene of Dakota: Bull. Am. Mus. 

Nat. Hist., vol. 5,1893, pp. 95-105.

Osborn, H. F,, and Wortman, J L , Fossil mammals of the lower Miocene White River beds: Bull. 

Am. Mus, Nat. Hist., vol, G, 1894, p. 200 (section).

cMatthew, W. D., Fossil mammals of the Tertiary of northeastern Colorado: Mem Am. Mus Nat. 

Hist., vol. 1, pt. 7,1901, p. 357.

d See Appendix, p. 91.

«Is the White River Tertiary an eolian formation? Am. Naturalist, vol. 33,1899, p. 404.
OF WESTERN NORTH AMERICA. 63

contains chiefly the Plains fauna, while the irregular " Metamynodon 

sandstones," traversing the lower Oreodon zone and of river-channel 

origin, contain chiefly the forest and aquatic fauna. (See fig. 9.) 

Forested, fluviatile, and plains or open-country conditions are indicated by the mingling of many mammals of modern type in the 

respective fluviatile and plains deposits.

Among Insectivora the first North American erinaceid .(Proterix) 

appears. Rodentia include 16 genera; we note the last appearance 

of the Eocene Ischyromyidse and the first appearance of the modern 

Muridse. Of Carm'vora-CanidEe, Cynodictis and DapJisenus continue 

from, the underlying Titanofherium zone; of Felidse, 3 genera of 

Machserodontinse; of Mustelidse, Bunsdurus. The Perissodactyla are 

reduced to 7 families: (a) Equidse (species numerous and diversified); 

(I) Tapiridse; (c) Lophiodontidse (their last appearance); (d) Amynodontidse (their last appearance); (e) RhinocerotidEe (including 

2 genera); (/) Hyracodontidse. Artiodactyla include 8 families:

(a) Leptochoeridae; (6) Elotheriidse; (c) Dicotylidse; (d) Agriochosridse; (e) Oreodontidse; (/) Camelidae; (</) Anthracotheriidse; (ti) 

Hypertragulidas.

UPPER OLIGOCENE, FIRST PHASE.

10. UPPER PART OF BRULE CLAY; LEPTAUCHENIA ZONE AND "PROTOCERAS

SANDSTONES."

(Figs. 1, 9, 10; Pis. I-III.) 

HOMOTAXIS.

North America. 1, Horizon C of the Hayden and Leidy section. 

2, Upper part of White River formation of South Dakota. 3, Brule 

clay (upper part) of Darton,a 1897. Leptauchenui zone of Wortman. 

The "Protoceras sandstones" contain the forest and fluviatile fauna; 

the clays of the Leptauclienia, zone contain the plains fauna. 4, 

Lower part of "Martin Canyon beds" of Matthew, 6 northeastern 

Colorado. 5, Deposits at White Buttes, North Dakota.

FAUNA. c

Characterized negatively, so far as we know, by disappearance or 

absence of the Hysenodontidae, the last of the archaic Mammalia; by 

extinction or absence of the Eocene Rodentia-Ischyromyidae; by 

extinction of 2 families of Perissodactyla, Lophiodontidse and 

Amynodontidse.

a Prof. Paper U. S. Geol. Survey No. 32,1905.

b Fossil mammals of the Tertiary oi northeastern Colorado: Mem. Am. Mus. Nat. Hist., vol. 1, pt. 7, 

1901, pp. 353-447. 

c See Appendix, p. 91.
64. CENOZOIC MAMMAL HORIZONS

Among Carnivora there now appear in North America representatives of all the existing families except (1) .Viverridse and Hyaenidae, 

which never reached America; (2) true Felinae, which first appear 

in the middle Miocene; (3) Procyonidae, which first appear in the 

lower Miocene; and (4) Ursidae, which first appear in the middle Pleistocene of North America. Among Rodentia is noted the first appearance (lower part of the John Day of Oregon) of the distinctively 

American Haplodontidae; also of the Castoridae (Steneofiber). Among 

Insectivora, first appearance of the Talpidae in North America (the 

Eocene forms with analogous teeth may be ancestral). Among surviving Perissodactyla is noted the presence of numerous larger members of the Equidae, Tapiridas, and Rhinocerotidae, the latter family 

including (a) members of the Diceratheriinae with very rudimentary 

horns, and (&) members of the Aceratheriinae of larger size. Artiodactyla now become very distinctive: Among Oreodontidae Leptauchenia and Eporeodon appear; among Anthracotheriidas Hyopotamus 

continues; among CamelidaeProfomen/x replaces Poebrotherium; among 

Hypertragulidae Protoceras (first appearance of this type) is the most 

distinctive form in the sandstones of South Dakota.

While the "Protoceras sandstones" and the clays of the Leptauchenia zone were being deposited in the Plains Region, there began the 

volcanic-ash depositions of the John Day formation in the Mountain 

Region of Oregon.

OREGON CENOZOIC FORMATIONS. 

RESUME OF THE OREGON DEPOSITS AS A WHOLE.

The known mammal fauna of Oregon, as determined partly by 

Cope and Wortman and more precisely as to levels by Merriam and. 

Sinclair, is found on five levels, partly separated by volcanic overflows, 

as follows:

Rattlesnake

Mascall

Upper part of John Day

Procamdus /one. 

Merychippus zone. 

Promerycochcerus /one.

Middle (fossils numerous) 

and (?) lower parts of 

John Day

= Diceraiherium /one

= upper Miocene

= middle Miocene

= Transition, upper OHgocene, lower Miocene

= upper Oligocene, second phase

JOHN DAY FORMATION.

(Figs. 1, 10, 11; PL I.)

Age. The time of the beginning of the John Day deposition appears 

to correspond with that of the close of the Leptauclienia zone in the 

South Dakota region (fig. 10), namely, the upper Oligocene.
U. S. GEOLOGICAL SURVEY BULLETIN NO. 361 PL.' Ill

Stcncofiber 

Promcrycoc7uf:ruf>

->*'l£$V 4 ^;;'^^^-^^::^^^^^-.^^-!:^ 

J ^M'riJ* ?fr^:^yfc:£S4^k-:.^^

r.**w^* 3^i^^^^^^ % ' ~ . i 1 Mtowft^ vv.. ^^'^ /^^jy i*V""p y*'" J ''.y

^^ " ' Vr; J'^'

 400 FEET

IDEALIZED BIRD'S-EYE VIEW OF THE GREAT BADLANDS OF SOUTH DAKOTA, SHOWING 

CHANNEL AND OVERFLOW DEPOSITS IN THE OLIGOCENE AND LOWER MIOCENE.

Looking southeast across Cheyenne and White rivers to Porcupine Butte, on Porcupine Creek, Pine Ridge Reservation. ' The location of the panorama is shown in PI. II, approximately on the line of section B. The ancient 

river-channel deposits in the successive levels are the " Titanothwmm sandstones," "Metamynodon sandstones," and "Protnccras sandstones." River-channel conglomerates appear in the Rosebud levels also.
co

FIG

NEBRASKA AND S.UAKOTA.

10. Provisional correlation of some of the chief epicontinental Oligocene-Pleistocene deposits and formations 

Unlike the sections in the other figures, these sections are not represented to scale; they are purely convent
66 CENOZOIC MAMMAL HORIZONS

Conditions of deposition. The volcanic materials of the John Day 

were chiefly wind blown, as described by Merriam; a there is little 

evidence of fluviatile conditions. The Mollusca are terrestrial or air 

breathing, with the exception of one locality which contains fluviatile 

Mollusca. The Testudinata, genus Stylemys, are of the Testudo, or 

terrestrial type; no fluviatile types have been recorded. The socalled beavers (Castoridse) are not the true river-living beavers 

£Peterson).

Fauna.b The known fauna of the John Day formation as a whole 

is chiefly of open-forest and savanna-living type. We note the entire 

disappearance of the ancient fauna, Creodonta-Hysenodontidse, and do 

not observe the introduction or invasion from Eurasia of any new 

families of mammals. The major part of the John Day fauna is of 

upper Oligocene age, but in its latest phases it is perhaps transitional 

to lower Miocene. The fauna is thus broadly transitional between 

that of the White Kiver group and the Arikaree formation.

The more ancient Ischyromyidae having disappeared, the modern 

Rodentia are represented by 6 existing families Sciuridse, Castoridae, 

Geomyidae, Muridse, Leporidae, and Haplodontidae (Allomys, Mylagaulodon). Among the Carnivora highly varied Canidse abound, the 

Felidse are numerous but confined to the machaerodont type, and 

there is a single member of the Mustelidae, Oligobunis. The Perissodactyla begin to be reduced to the 3 existing families of Equidse, 

Tapiridae, and Rhinocerotidae; the aberrant Chalicotheriidae occur. 

Among Artiodactyla, the Elotheriidae attain a great size; in the middle 

part of the John Day the peccary-like pigs, Dicotylidse, are found in 

great numbers; a wider differentiation arises among the Oreodontidae, 

but Leptauclienia, does not occur here. In the upper part of the John 

Day the members of the Camelidae are first recorded (Sinclair) and 

begin to attain considerable size; a species of Paratylopus or Miolabis 

occurs, resembling the species of the lower Arikaree. The lower 

John Day fauna is so little known that no deductions can be made 

from it, except that it appears to be closely related to that of the 

middle John Day.

The faunistic comparison of the John Day formation therefore 

begins with the middle John Day, which is highly fossiliferous and 

slightly more advanced than that of the upper portion of the Brule 

clay and " Protoceras sandstones," as will now be shown.

a A contribution to the geology of the John Day basin; -Bull. Univ. California, Dept. Geology* vol. 2, 

1901, pp. 269-314. 

b See Appendix, p. 91.
OF WESTERN NORTH AMERICA. 67

UPPER OLIGOCENE, SECOND PHASE (EUROPE, ETAGE AQUITANIEN).

11. MIDDLE PART OF JOHN DAY FORMATION; DICERATHERIUM ZONE (ALSO 

UPPER PART OF JOHN DAY, TRANSITIONAL).

(Figs. 1, 10, 11; PI. I). 

HOMOTAXIS AND SYNONYMY.

America. 1, Middle part of the John Day formation of Oregon. 0 

2, Diceratlierium zone of Wortman (500 to 1,000 feet).

Europe. Aquitanien. Homotaxis with the Aquitanien of France 

(typified by the St. Gerand-le-Puy, Allier) is close, as indicated by

500-

1000'

250- 

300'

Columbia River lava' 

v (basalt flow, 2000 feet)

Forest on top of ashes 

Camelidae

JH-^jr^^T-^^^TgTgEr (fossils, numerous)

^j^-^^j^r^jIrEjr^rGr^r^A-^. Remains of 

~ ~ *-* tuff deposits

' C"\-/ ' /> r-'~' y/.^'/ ?' ~ ^/"/VO >'PbyPlJ't'C "Af low

Diceratheriinae,

Elotherwm, 

?=^^2-^^^E^^°jne=^f3. ?0reodon

S^^^^^^^^^^^^^^^^SrE^r^^k (fossils, scarce)

FIG. 11. Columnar section of the John Day formation (Oregon), based on studies by Merrlam and

Sinclair,

similar stages in the evolution of Perissodactyla-Tapirida3, Diceratheriinse, Aceratheriinse, Chalicotheriidae, and other families.

FAUNA. 6

The evolution stages in members of this typical Mountain fauna of 

the middle part of the John Day are in some families (e. g., Equidse,

a Merriam, J, C., op. cit.

6 Full John Day lists were kindly prepared for this paper by Dr. William J. Sinclair from Professor 

Merriam's and his own personal notes. (See also Appendix, p. 91.)
68 CENOZOIC MAMMAL HORIZONS

Tapiridse) similar to those of the Brule clay, in others (e. g., Rhinocerotoidea, Rodentia) more advanced than those of the upper Brule 

clay and "Protoceras sandstones." This more or less progressive 

character is illustrated as follows: Among Perissodactyla-Rhinocerotidse -Dicemtherium is more advanced, with well-developed horn 

cores; among Tapiridse Protapirus is similar to that in the "Protoceras sandstones;" among Equidse browsing horses-, small and similar 

to those of the "Protoceras sandstones." Among Artiodactyla 5 

families: Elotheriidse, Hypertragulidae, Oreodontidse (Eporeodon, 

Agriochcerus), Dicotylidse, Camelidae (not certainly present). Among 

Carnivora-Felidse (Archselurus, Nimravus) ; among Canidse Nothocyon, 

Temnocyon, Mesocyon, PJiilotrox. Among Rodentia Leporidse (Lepus), 

Castoridae (Steneofiber); also two new and peculiarly American rodent 

families, Geomyidse (pocket gophers) and Haplodontidae (sewellels, 

Meniscomys).

The conclusion is that the middle John Day deposition partly 

overlaps and is partly sequent to the deposition of the upper part of 

the Brule clay and the "Protoceras sandstones."

UPPER OLIGOCENE, LATEST PHASE (EUROPE, ETAGE AQUITANIEN). 

12. UPPER PAET OF JOHN DAY FORMATION; PROMERYCOCHOERUS ZONE.

(Figs. 1, 10, 11; PL I.)

HOMOTAXIS.

North America (provisional). Great Plains: 1, Lower portion, of 

Rosebud, of Matthew. 2, Gering, of Peterson's Running Water section. (See fig. 13.) 3, ? Gering, of Darton's Scotts Bluff section.

FAUNA,a EARLY PHASE.

The fauna of the upper part of the John Day formation is rich, but 

the levels have been certainly recorded only in the case of the following animals: Among Rodentia, Lepus, Entoptychus, Mylagaulodon. 

Among Carnivora-Canidae, Nothocyon, Mesocyon, Temnocyon. Among 

Perissodactyla, (a) Equidse, Anchitherium prsestans, Mesoliippus acutidens; (Z>) Tapiridse, Protapirus; (c) Rhinocerotidse, ? Diceratheriinae, 

? Aceratheriinae. Among Artiodactyla, (a] Elotheriidae, (&) Dicotylidse, (c) Oreodontidse, Promerycocliazrus, 4 species, Eporeodon, (d) 

Hypertragulidse, (e) Camelidee, Paratylopus sternbergi, P. cameloides. b

TRANSITION FROM UPPER OLIGOCENE TO LOWER MIOCENE IN UPPER 

PARTS OF JOHN DAY, GERING, AND HARRISON AND LOWERMOST PART 

OF ROSEBUD.

From the preceding American Oligocene (upper part of Brule clay 

or Leptauchenia zone, and lower and middle parts of the John Day)

a See Appendix, p. 91.

f» The only camels from the John Day obtained by the University of California expeditions came from 

the top of the formation. The matrix of the type of P. sternbergi shows that it is not from the middle 

John Day, as Wortman supposed (Sinclair, November, 1906).
OF WESTERN" NORTH AMERICA. 69

the transition beds are sharply demarcated positively (1) by the sudden appearance among Artiodactyla-Oreodontidse of Promerycochcerus 

followed in higher levels by Merycoch&rus and Merycliyus; (2) by the 

survival of progressive species of Leptcmclienia in the same family; (3) 

among Artiodactyla also, 3 families of earlier horizons apparently 

have become extinct, namely, Anthracotheriidse (which also disappear 

in the Aquitanien of France), Leptochreridse, and OreodontidseAgriochcerinse.

COMPARISON WITH EUROPEAN HORIZONS OF UPPER OLIGOCENE AGE.

The upper part of the John Day formation, or Promerycoclicerus 

zone, of the Mountain region of Oregon, as well as the Gering and 

Monroe Creek formations of Hatcher, the Gering or lower Arikaree of 

Darton, the Rosebud (lower levels, see fig. 12) of Matthew, all in the 

Plains region of South Dakota, may be regarded as covering the transition between the Oligocene and Miocene epochs, as these divisions are 

employed in France. They resemble chiefly the upper Oligocene of 

France. (1) The upper part of the John Day of the Mountain region 

is somewhat older than the lower part of the Rosebud of the Plains, 

although both contain Promerycochcerus. (2) Recent explorations in 

the upper portion of the Harrison and equivalent formations a reveal 

a fauna which partly resembles that of the upper Oligocene of France 

(an Oligocene character is given by the survival of Elotherium); at the 

same time, it contains a primitive AmpJiicyon, a-characteristic Miocene 

form. The newer fauna of these beds is slightly subsequent to that of 

St. Gerand-le-Puy (generally regarded as upper Oligocene or Aquitanien, although several authorities place it in the lower Miocene). (3) The 

resemblance to the Aquitanien consists in the presence of Rhinocerotoidea-DiceratheriinEe, in the nonappearance of Mastodon among Proboscidea, and in the nona°ppearance of Teleoceras among Rhinocerotoidea. (4) It differs from the Aquitanien proper in the survival of 

Artiodactyla-Elotheriidse, which disappear in the middle Oligocene of 

France. (5) It contains Chalicotheriidse apparently near Macrotherium, a Miocene stage. (6) From a recent comparison of these fauna, 

Matthew writes (March, 1907):

The above comparisons indicate that the Rosebud faunae are later than the upper 

Oligocene and earlier than the middle Miocene of the European standard. Their 

position is thereby fixed as lower Miocene, representing an earlier and a later stage.

It is concluded that the upper part of the John Day, for the present, 

may be somewhat arbitrarily separated as the American upper Oligocene, while the partly contemporaneous and partly sequent Plains 

formations may-be termed lower Miocene.

a Matthew, W. D., A lower Miocene fauna from South Dakota: Bull. Am. Mus. Nat. Hist., vol. 23, 

1907, pp. 169-219.

"From these discoveries it appears that the Miocene section from the Oligocene to the top of the 

Nebraska beds, in this general locality, may perhaps have to be regarded as lower Miocene." Peterson, 

0. A., The Agate Spring fossil quarry: Ann. Carnegie Mus., vol. 3, No. 4, 1900, p. 491.
70 CENOZOIC MAMMAL HORIZONS

MIOCENE.

IV. FOURTH FATJNAL PHASE Continued.

LOWER MIOCENE (EUROPE, ETAGES AQUITANIEN, BURDIGALIEN).

13. ARIKAREE FORMATION, PROMERYCOCHffiRTTS ZONE (OERING, MONROE 

CREEK, HARRISON, AND ROSEBUD OF DARTON, HATCHER, AND MATTHEW).

(Figs. 1, 10, 12-14; PL I.) 

GENERAL FEATURES.

Geology and nomenclature. -This Great Plains formation, officially 

designated Arikaree by the Survey was recognized as horizon D by 

Hayden, and, as shown in the synonymy below (p. 71), has been variously divided and named by Darton, Hatcher, and Matthew. It ig

Porcupine Butte 

'Volcanic ash layer

Merycochcertzs 

zone

8/astomeryx 

Parahippus

Protomeryx 

Merycochcerus 

Merychyus (abundant)

Calcarepus_shaly

.'.;' v^limestone layers

Promerycochaerus

_ £.-X\ Promery- (veryabundant 

i£v.Y-.\\ codhoeros and characteristic) 

zone Diceratherium 

Elotherium 

Steneof/ber 

Hypertragulus 

Parahippus (smallsp.) 

__ Leptauchenia 

^ ^ ^j^gg^gg' (near base)

FiG. 12. Columnar section of the Rosebud fonnation, after observations by Matthew and Thomson, 

1906. For the chief line of this section see section B, PI. II.

extensively exposed along the Pine Ridge Bluffs of South Dakota on 

the south side of White River and along Niobrara River, as mapped 

by Darton.a (See PL I.) It extends more than 100 miles east and

a Preliminary report on the geology and water resources of the central Great Plains: Prof. Paper 

U. S. Geol. Survey No. 32, 1905, pi. 35.
OF WESTERN NORTH AMERICA.

west. It immediately overlies throughout, conformably or unconformably, the upper part of the Brule clay or Leptauchenia zone.. In. 

some places lithologically, and everywhere faunistically, it can be 

divided into lower and upper levels.

Synonymy. The typical Gering formation of Darton, 1899, is at 

Scotts Bluff, western Nebraska; the broad extension by Darton of 

this formation to other localities is somewhat doubtful. The name 

Gering formation as used by Darton, Hatcher, and Peterson probably 

applies to noncontinuous river sandstones and conglomerates (maximum 200 feet), which are in a manner analogous to the "Titanotlierium," "Metamynodon," and "Protoceras sandstones" .that traverse 

the lower Arikaree clays or finer beds and partly erode irregular channels in the upper Brule clay (Leptauckenia zone). This formation is 

thus probably of the same age as the lower parts of the Arikaree, 

Monroe Creek, and Rosebud. Its known fauna is very limited. The 

so-called Gering of Hatcher and Peterson is in southeastern Wyoming and northwestern Nebraska; in their section it is said to be 

lithologically similar to the overlying Monroe Creek.

The typical Arikaree formation of Darton, 1899, is at Pine Ridge 

Bluffs, in South Dakota; nsvhether or not this extends to southeastern Wyoming rests on future paleontological correlation. The Arikaree as described and mapped by Darton would broadly include the 

whole of the Rosebud formation of Matthew, as well as the Monroe 

Creek and Harrison, and broadly cover the whole of the Miocene. The 

entire Arikaree formation of Darton consists of finer materials, whitish 

or light-buff sandstones, more continuous and widespread, lying either 

on the Gering formation or on the Brule clay.

There remain to be compared, therefore, the faunae contained in two 

sections about 95 miles apart east and west, probably continuous, substantially similar lithologically, and containing a substantially similar 

fauna. This comparison is based on the valuable recent papers of 

Peterson and Matthew (cit. supra). The local names Monroe Creek, 

Harrison, and Rosebud may all be retained until the question of geologic identity or dissimilarity can be settled.

Approximate correlations of the Arikaree formation.

Upper division .... 

Lower division ....

Westerly section: Southeastern Wyoming and northwestern Nebraska. 

Hatcher, 1902; Peterson, 1906. (See 

fig. 13.)

Upper part of Monroe Creek ..... 

Lower part of Monroe Creek 

(Gering of Hatcher and Peterson). 

Upper part of Brule clay, or Leptauchenia zone.

Feet. 

200 

200 

300 

200

150

Easterly section: South Dakota, Porcupine Creek. Matthew, Giclley, 1904; 

Matthew, Thomson, 1900. (See fig. 

12.)

Upper part of Brnie clay, or Lr.ptauchenia zone.

Feet. 

«250

a 250

« Estimated.
ARIKAREE FORMATION

&l

 . Q

3 B"y

g

ens -

2 S

3 §

* o 

n> CD

? O

g^.W |i

8 3.

rf cc

o g B 5,

> 2"

o 

II

MONROE CREEK 

3 <* 50

r 
OF WESTERN NORTH AMERICA. 73

WESTERLY SECTION.

(Figs. 13, 14.)

The recognition of this fauna ft is the most important advance of 

recent mammalian paleontology in North America. As observed 

by Peterson,5 continuing the observations of Hatcher/ in a section run through northwestern Nebraska and southeastern Wyoming, we find three distinct formations, as described below.

A. LOWER DIVISION.

(a} Gering formation (or lower part of Monroe Greek). Among 

Artiodactyla-Oreodontidse, Mesoreodon, Leptauclienia. The species 

of Leptauchenia are but slightly more progressive than those (L. 

decora, L. nitida) of the underlying Leptauchenia, zone or upper part 

of the Brule clay.

(b) Monroe Creek formation. Among Artiodactyla-Oreodontidae, 

Mesoreodon, Promerycocfiosrus, Phenacoccelus; among Camelidse,

FIG. 14. Diagrammatic section of the Gering, Monroe Creek, and Harrison formations of western 

Nebraska. Modified from Peterson, 1906. For the line of this section see section A, PI. II.

Protomeryx; among Rodentia, Euhapsis platyceps; among Canidse, 

NotJiocyon; among Rhinocerotidie. Diceratlierium.

(c) Harrison formation, Hatcher. These are the "Dsemonelix 

beds" of Barbour. The great spirals or corkscrews to which the 

name Dsemonelix was applied are found to contain remains of the 

characteristic lower Miocene rodents, C&sioridse-Steneqfiber (an 

aberrant castoroid), and are believed by Peterson d to represent the 

burrows of this rodent. The original theory of Barbour (1892) 

was that these corkscrews represent the spiral roots of some giant 

plant. Neither theory is entirely satisfactory. The Harrison formaa See Appendix, p. 91.

l> The, Miocene beds, etc.: Ann. Carnegie Mus., vol. 4, 1906, p. 23.

c Origin of the Oligocene and Miocene deposits of the Great Plains: Proc. Am. Philos. Soc., vol. 41, 

1002, pp. 118-119. 

d Mem. Carnegie Mus., vol. 2, 1905, pp. 139-191.
 74 CENOZOIC MAMMAL HORIZONS

tion contains, among Oreodontidse, Promerycochwrus (P. vantasselensis), Phenacoccelus (P. typus ), also a primitive brachyodont stage 

of Merychyus; among Camelidae, two brachyodont genera, namely, 

Miolabis and a related form, Oxydactylus; Stenomylus, a cameloid 

of the Hypisodus type; a among Hypertragulidse, Syndyoceras ,6 which 

replaces Protoceras (of the upper Brule level); among Dicotylidae, 

primitive species of Desmathyus; among Rodentia-Castoridae, Steneofiber, very abundant (2 sp.); among Equidse, ParaMppus; among 

Mustelidse, Brachypsalis. '

(d) Harrison formation, Agate Spring quarry. Near the middle 

of the Harrison formation is the extraordinarily rich deposit of this 

quarry, which gives us a nearly if not quite complete picture of the 

larger mammals of this region and period. So far as described by 

Peterson/ it contains, among Perissodactyla-Equidse, ParaMppus; 

among Rhinocerotidse, Diceratherium, 2 species; among Chalicotheriidae, Moropus; among Artiodactyla-Oreodontidas, Merychyus and 

IMerycochosfrus; among Elotheriidae, Dinohyus, a giant form similar 

to the large John Day types and probably the last of its family;' 

among Carnivora-Canidae, Noihocyon, AmpMcyon (a very primitive 

form, its earliest appearance in America).

B. UPPER DIVISION.

(e) Upper part of Harrison formation. 11 Among ArtiodactylaOreodontidae, Merycochoerus (first abundant appearance of this 

genus), Merychyus; among Camelidae, ? Miolabis and Oxydactylus, 2 

species; the first appearance of the familyCervidse, genus Blastomeryx, 

a modernized selenodont artiodactyl; Dicotylidae, Desmathyus; 

among Perissodactyla-Equidse, Parahippus, a large brachyodont horse 

constituting the most abundant type and most characteristic stage; 

among Chalicotheriidse, Moropus; among Carnivora-Mustelidae, Mlurocyon. Also 2 species of Testudo.

EASTERLY SECTION.

(Fig. 12.)

About 90 miles farther east along Pine Ridge in northern Nebraska 

and on the south side of White River is the formation, also overlying the upper Brule clay, named by Matthew and Gidley e (1904) the 

Rosebud beds. This is the region of the typical Arikaree section of 

Darton, described and named in 1899. The section (fig. 12) was 

made by Albert Thomson, of the American Museum expedition of 1906.

a Peterson, op. cit.

6 Barbour, E. H. ? Notice of a new fossil mammal from Sioux County, Nebr.: Nebraska Geol. Survey, vol. 2, pt. 3.

c The Miocene beds of western Nebraska, etc.: Ann. Carnegie Mus., vol. 4, 1906, pp. 21-72.

d Erroneously termed "Nebraska" in Peterson's first report. The Agate Spring fossil quarry: 

Ann. Carnegie Mus., vol. 3, 1906, p. 487.

e New or little known mammals from the Miocene of South Dakota: Bull. Am. Mus. Nat. Hist., vol. 

20, 1904, pp. 241-268.
OF WESTERN NORTH AMERICA. 75

As analyzed by Matthewa it is to be'noted that: (1) The Rosebud 

fauna contains no new immigrants, but is mainly a further development of the John Day fauna; all the animals exhibit slightly or 

decidedly more progressive stages. For example, the camels of the 

Monroe Creek, Harrison, and Rosebud are decidedly more advanced 

than anything from the upper part of the John Day, as are also the 

horses, carnivores, rodents, and oreodonts. (2) This fauna was distributed farther out in the Plains Region, a circumstance that may 

have differentiated it locally from the more westerly fauna of the 

Monroe Creek and Harrison formations, which was presumably near 

the sources of the water supply, forests, etc. This fact of local distribution may account for some differences in comparison with the 

Monroe Creek and Harrison lists above. These differences may be 

reduced or increased by further exploration.

A. LOWER PART OF ROSEBUD.

Homotaxis. I, Lower part of Rosebud of Matthew; 2, Gering 

of Darton, Hatcher, and Peterson; 3, Monroe Creek of Hatcher; 

4, Harrison of Hatcher; 5, Middle portion of "Martin Canyon 

beds" of Matthew, Colorado.

Fauna. b Among Carnivora, Nothocyon, Mesocyon, Enhydrocyon, 

Nimravus; among Rodentia, Entoptyclius, Steneofiber, Euliapsis, 

Meniscomys, Lepus; among Perissodactyla, Pamliippus, lAnchitlierium, Diceratlierium; among Artiodactyla, Elotherium, Eporeodori, 

Mesoreodon, Promerycoclice/rus (very abundant and characteristic), 

Leptauchenia, and Hypertragulus.

B. UPPER PART OF ROSEBUD.

Homotaxis. 1, Upper part of Rosebud of Matthew. 2, Deposits 

near Laramie Peak, Wyoming. 3, Upper part of Harrison of Peterson, western Nebraska. 4, Summit of "Martin Canyon beds" of 

Matthew, Colorado.

Fauna. (1) Few species pass from the lower part of the Rosebud 

into the upper part. (2) The Elotheriidse, Hypertragulidae, and 

Prornerycocharus have probably disappeared. (3) The Diceratheriinse 

continue. Among Carnivora, Cynodesmus, Megalictis, Oligobunis. 

Among Insectivora, Arctoryctes (a supposed member of the Chrysochloridse). Among Rodentia-Geomyidae, Entoptychus, Lepus, and a 

heteromyid. Among Perissodactyla, 2 families: Parahippus, other 

Equidse, Diceratherium. Among Artiodactyla, 4 families: (a) Dicotylidse, Desmathyus; (&) among Oreodontidse, Merychyus is extremely abundant and characteristic; Merycochcerus also appears 

for the first time; (c) Camelidse, Protomeryx; (d) Cervidse, Blastomeryx.

" A lower Miocene fauna from South Dakota: Bull. Am. Mus. Nat. Hist., vol. 23, 1907, pp. 1G9-219. 

(> See Appendix, p. 91.
76 CENOZOIC MAMMAL HOBIZONS

V. FIFTH FATJNAL PHASE.

Fresh migrations via Eurasia First appearance of African Proboscidea, 

of true Felinse among the Felidse, of short-limbed Teleocerinee among 

Rhinocerotoidea, animals occurring in the lower Miocene of Europe 

Evidence of increasing summer droughts.

MIDDLE MIOCENE (EUROPE, ETAGES HELVETIEN, SARMATIEN,

TORTONIEN).

FAUNAL CHANGES.

1. North America. In the formations which are now commonly 

classed as middle Miocene, but which may prove to represent lower 

and middle Miocene, we meet another very profound change in the 

mammals of North America. This change is threefold: It consists (a) 

in the occurrence of more advanced evolutionary stages, among the 

Camelidae and Equidae especially; (&) in the extinction of many mammals characteristic of the Harrisonor upper Rosebud or lower Arikaree, which we are here considering lower Miocene; (c) in the sudden 

appearance of a large number of new forms of African (Proboscidea) 

and Eurasiatic (e. g., Rhinocerotidse, Teleocerinae, Pecora) origin. 

The appearance of several modernized selenodont artiodactyls or 

Pecora must have effected a change in the external aspects of the 

fauna which was only less striking than that caused by the mastodons and the bulky rhinoceroses.

2. Europe. As regards (&) and (c), a similar extinction and sudden appearance also mark the base of- the European Miocene, the 

Langhien or Burdigalien as represented by the Sables de I'Orl^anais 

of Europe. The conclusion is that these North American middle 

Miocene formations contain animals which first appear in the lower 

Miocene of Europe, just as the American lower Miocene contains 

animals which first appear in the upper Oligocene of Europe. At 

least, this is the hypothesis on which our correlations are based at 

present, allowing considerable time for migration from the old to the 

new world.

14. DEEP RIVER SEQUENCE, SCOTT; TICHOLEPTUS ZONE, COPE.

(Figs. I, 10; Pi. I.) 

HOMOTAXIS.

America. This is in large part the "Loup Fork fauna" of Cope's 

descriptions, because his materials were chiefly from this level in 

Colorado and Oregon beds, (a) Central Plains: 1, Horizon E of 

Hayden and Leidy; 2, "Pawnee Creek beds" of Matthew, northeastern Colorado (75 feet), immediately overlying the Harrison; 

3, "Panhandle beds" of Gidley, northwestern Texas. (&) Northern 

Plains: 4, Upper part of Deep River sequence (Smith Creek) or 

Ticholeptus. zone (of Cope), Montana' 5, "Flint Creek beds" of
OF WESTERN NORTH AMERICA. 77

Douglass (150 feet), Montana, (c) Mountain Region: 6, Mascall formation, Oregon (lower part, 1,000 feet), capping the Columbia River 

lava (1,000 feet), which in turn overlies the John Day formation. 

The Colorado (Matthew") and Montana (Scott,6 Douglass 0) faunae 

are the best known and are closely equivalent in age.

Europe. Homotaxis with Europe is pro visional, owing to: (1) Uncertainty as to what we should regard as the base of the American 

Miocene; (2) uncertainty as to the speed or rate of migration from 

Europe. The new mammals of this stage (viz, Proboscidea, Teleocerinae, and Pecora) are all from Europe, where they form the chief 

characteristics of the lower Miocene; but we may suppose that these 

animals occupied a portion of the lower Miocene period in migrating 

from western Europe to North America.

FAUNA.d

1. Scott first (1893 e) fully characterized the upper Deep River 

fauna of Montana as prior to the so-called "Loup Fork" of Colorado.

2. Matthew f first (1901) clearly distinguished the fauna of our 

so-called middle Miocene ("Pawnee Creek") from that of the upper 

Miocene or typical Niobrara River "Loup Fork" of Hayden, and the 

above correlations are chiefly due to him.

3. Its negative characters are: Nonoccurrence of ArtiodactylaElotheriidae and Hypertraguliclae (which apparently became extinct 

during the lower Rosebud); of Perissodactyla-Diceratheriinae (whichapparently became extinct during the upper Rosebud).

4. Its positive or new characters are: (1) The first appearance of 

Proboscidea by migration from Africa. (2) By migration from western- Europe or Eurasia: Among Carnivora 2 new and distinctive 

Eurasiatic subfamilies (a) true Felidae-Felinae, Pseudsdurus; (1)) 

Canidae-Amphicyoninae, Amphicyon. Among Perissodactyla-Rhinocerotoidea, a member of the Teleocerinae closely similar to the 

lower Miocene Teleoceras aurelianensis of France. Among Artiodactyla-Cervidae, Palseomeryx; other peculiarly American modernized 

ruminants, Merycodus (family Antilocapridae), date from this stage. 

Among Rodentia the new family Mylagaulidae (also American) 

appears. Thus in our so-called middle Miocene the peculiarly 

American Hypertragulidae disappear; the European Cervidae and the 

peculiarly American Merycodontinae take their places.

a Matthew, W, D., Fossil mammals of the Tertiary of northwestern Colorado: Mem. Am. Mus. Nat. 

Hist., vol. 1, pt. 7, Nov., 1901, pp. 355-447.

& Scott, W. B., The Mammalia of tha Deep River beds: Trans. Am. Philos. Soc., n. s., vol. 18, 1895, 

pp. 55-185.

c Douglass, Earl, The Neocene lake beds of western Montana: Univ. Montana, doctorate thesis 

June, 1899. New vertebrates from the Montana territory: Ann. Carnegie Mus., vol. 2,1903.

d See Appendix, p. 91.

« Scott, W. B. The mammals of the Deep River beds: Am. Naturalist, vol. 27,1893, pp. 659-662. The 

Mammalia of the Deep River beds: Trans. Am. Philos. Soc., n. s., vol. 18,1895, pp. 5.5-185.

/Matthew, W. D., op. cit., pp. 358-374.
78 CENOZOIC MAMMAL HORIZONS

Plains fauna. Of local evolution on the Great Plains the Equidae 

exhibit, as the most distinctive genus, the first of the Hippotheriinae 

or Merychippus stage of horses with subhypsodont molar teeth; the 

large brachyodont HypoJiippus is also found, as well as Parahippus. 

Among Rhinocerotidas, the hornless ApJielops first occurs, also Teleoceras. Among Tapiridae, Tapiravus. Among Camelidse, Miolabis 

continues, Protolabis appears, and Alticamelus succeeds Oxydactylus. 

Among Oreodontidae, the family reaches a climax of differentiation 

in 7 genera, including Merychyus and Merycochoerus, but adding the 

very characteristic genera Ticholeptus and Cydopidius, which are 

probably direct descendants of Eporeodon and Leptauchenia of the 

preceding stage. Among Rodentia-Mylagaulidae, Mylagaulus, Oeratogaulus. Among Canidae, Cynarctus, Amphicyon, and other less 

aberrant genera.

Mountain Region fauna of the Mascall formation. The Mascall formation of Oregon, overlying the Columbia River lava and subjacent 

John Day, is partly homotaxial with the middle and upper Miocene. 

The fauna, sparsely known, includes very primitive horses with 

short-crowned teeth (ArchseoJiippus, Parahippus) ; also the more progressive Merychippus, which is characteristically middle Miocene, 

although it persists into the upper Miocene. We find Miolabis among 

Camelidae. Among Cervidae, Palseomenjx. Among Proboscidea, Trilophodon. An ungual phalanx of the Edentata-Gravigrada type is 

certainly reported from these beds (Sinclair); the true South American Gravigrada are first known to occur in the middle Pliocene 

(Blanco formation of Texas).

MOUNTAIN EEGION FLOKA.

The flora seems to point to a more recent age for these beds, but 

American florae generally are more progressive than the vertebrate 

fauna. The Mascall flora was considered upper Miocene by Lesquereux. Knowlton a also concludes that the flora is of upper Miocene 

age; from.his list cited by Merriam6 (1901), Hollick c observes:

I judge that the meteorological, climatal, and physiographic conditions indicated 

would be comparable to those now- met with on the Atlantic coastal plain at about 

the latitude of the Carolinas. A majority of the trees, such as Salix, Quercus, Planus, 

Aralia, Acer, Primus, etc., belong to the Temperate Zone, and represent a flora similar 

to that of this vicinity [New York, lat. 42° N.]. Accompanying these, however, are 

a few of more southern distribution, such as Taxodium, Laurus, Sapindus. and Ficus?, 

which indicate that the flora as a whole should be regarded as warm-temperate. The 

indicated moisture factor is a little more difficult to determine. Marsilea is an aquatic 

plant, and the characteristic habitat of Taxodium is swamp land, while the other 

genera might represent either lowland or upland species.

« Knowlton, F. H., Fossil flora of the John Day basin: Bull. U. S. Geol. Survey No. 204,1902, p. 108. 

6 Merriam, J. C., A contribution to the geology of the John Day basin: Bull. Dept. Geology, Univ. 

California, vol. 2,1901, pp. 308, 309. 

c Letter of February 6,1906. .
OP WESTERN NORTH AMERICA. 79

UPPER MIOCENE (EUROPE, ETAGE PONTIEN). 

15. OGALALLA FORMATION (IN PAET); PKOCAMELUS ZONE.

(Figs. 1, 10; PL I.) 

HOMOTAXIS AND SYNONYMY.

' North America. This includes the "Loup Fork" of Leidy, Marsh, 

also of Scott and Osborn, in part. 1, " Nebraska" of Scott, 1894, 

western Nebraska.0 2, Cosoryx zone, Scott,b 1894. (The genus 

Cosoryx is preoccupied by Merycodus, so. it appears that this name 

can not be used.) 3, Ogalalla and Arikaree of Darton (in part), 

1899, western Nebraska. 4, Protohippus zone of Osborn, 1907. 5, 

"Santa Fe marls " of Cope, New Mexico. 6, "Clarendon beds " of Gidley, Llano Estacado, northwestern Texas (7'5 feet). Northern Plains: 

7, "Madison Valley beds" of Douglass, Montana (1,200 feet).

Europe. Etage Pontien, Pikermi, Eppelsheim. The so-called 

"Loup Fork mammals," although including Hipparion, are not quite 

so modernized as those of Eppelsheim and Pikermi, which should be 

regarded as lower Pliocene.

This fauna has become universally known as the "Loup Fork 

fauna" (Cope, 1877), owing to errors on the part of Hayden, Leidy, 

Cope, and their successors, arising from the confusion of late Miocene 

and upper Pliocene faunae. But, as shown fully on page 84, the term 

"Loup Fork" is equivalent to "Loup River," and the latter term 

was originally applied so as to include an upper Pliocene or lower 

Pleistocene formation containing Eleplias imperator.

FAUNA. 0

This is one of the best known, most widely distributed, and 

most characteristic faunae in all the Tertiary series. There is no 

evidence of a fresh Eurasiatic migration, but rather of rapid local 

evolution. The genus Protohippus distinguishes it clearly from the 

middle Miocene, which contains Merychippus only. Other new distinctive genera are the camels Procamelus and Pliauchenia, the 

horse NeoTiipparion, and the rhinoceros Peraceras. The wide distribution of a similar fauna at this stage indicates widespread conditions of aridity and a uniformly favorable environment, summer 

droughts probably lengthening and eolian deposits increasing. ^ From 

Montana on the northwest and Texas on the southwest to Nebraska 

in the central west we find a very similar list of animals; so the homoa Bull. Geol. Soc. America, vol. 5,1894, p. 595.

b Under a misapprehension as to Scott's definition of the term '' Nebraska," both Hatcher and Peterson first applied this term to a part of the lower Arikaree or lower Miocene.

< Matthew. W. D., and Gidley. J, W., New or little known mammals from the Miocene of South Dakota, 

etc.: Bull. Am. Mus. Nat. Hist., vol.20,1904, pp 241-2G8. See Appendix, p. 91.
80 CENOZOIC MAMMAL HORIZONS

taxis of the American horizons "Nebraska/' "Clarendon beds/' 

"Santa Fe marls/' and "Madison Valley beds" is singularly well 

established.

Among Rodentia-Mylagaulidse, 1 genus. Among Sciuridse, 2 genera. Among Carnivora-Canidse, JElurodon, Cynodesmus(1}, Bowphagus, Dinocyon(f~), and Ischyrocyon.. Among Mustelidse,. Mustela, 

Lutra, Potamotherium^Brachypsalis, Putorius. Among Felidse, Pseudddurus (Felis of Leidy), and large machserodbnts of uncertain genus. 

Among Procyonidse, Leptarctus. Among Perissodactyla, 3 families: 

(a,} among Equidse (5 genera), ProtoJiippus (5 or more species), Neohipparion (5-12 species) with long crowned teeth, Merychippus persisting with intermediate teeth, Hypohippus and ParaMppus (Montana) persisting with short-crowned teeth; (6) among RhinocerotidaBTeleocerinse, 2 genera of the short-limbed type occur Teleoceras, 

Peraceras, also Aphelops ceratorhinus; (c) amo'ng Tapiridse, Tapira/vus. 

Among Artiodactyla, 5 families: (a) Camelidse, including PliaucJienia (its first appearance, 2 or more species), Procamelus (its first 

appearance/ 2-7 species); (&) among Oreodontidse, MerycocluErus (2 

species, Montana), Merychyus, Pronomoiherium; (c) among Merycodontinae, Merycodus; (d) among Dicotylidse, ProstJiennops (Montana) ; 

(e) among Cervidse, Palseomeryx (5 species), Blastomeryx. Among 

Proboscidea there occur the long-jawed types analogous to Trilophodon cmgustidens of Europe.

LAST PHASE OF MIOCENE OR FIRST PHASE 07 PLIOCENE (EUROPE, 

ETAGES PONTIEN, MESSINIEN).

A late phase of Miocene, or early phase of Pliocene, is the deposit 

on Republican River, in northern Kansas. It is, provisionally and 

subject to further exploration, distinguished (Matthew) from the 

so-called " Loup Fork," or " Nebraska," of Scott. Its fauna presents 

certain parallels with the Pikermi and Eppelsheim fauna (placed by 

Deperet in the upper Miocene) of Europe, even if not of more recent 

age. It is widely separate from a second and much later phase, represented in the Blanco formation of northwestern Texas, which is 

much more recent in its fauna and is here regarded as middle Pliocene.

16. OGALALLA FORMATION (IN PART); PERACERAS ZONE.

(Figs. 1, 10; PL I.) 

HOMOTAXIS.

America. 1, Upper "Loup Fork" (100 feet) of Republican River, 

northwestern Kansas. 2, Ogalalla formation (typical), Darton, of 

southwestern Nebraska. 3, "Archer formation " of Florida (in part). 

4, Rattlesnake formation of John Day Valley, Oregon.

Europe. Pontien: Eppelsheim, in northern Europe; Pikermi, in 

Greece; Mont Leberon, Vaucluse, France.
OF WESTERN NORTH AMERICA. 81

FAUNA/'

From our present knowledge, the close of the Miocene or advent of 

the Pliocene may be characterized: Negatively, (1) by the absence of 

Artiodactyla-Oreodonticlae and the rarity of MerycJiyus, MerycoclioKrus, etc., which thus far are represented only by fragmentary 

specimens; (2) by some reduction in the number of Camelidse (in this 

family PliaucJienia is now the characteristic genus); (3) by the rarity 

. of the browsing horses (Hypohippus) ; (4) by the disappearance of the 

Perissodactyla-Chalicotheriidas. Probably some of these absent 

forms will be unearthed by future exploration. Positively, (1) by 

the more advanced evolution of the Rhinocerotidae in progressive 

species of Teleoceras, Peraceras, and ApJielops; (2) by more progressive but still long-jawed forms of Proboscidea-Mastodontidae, with 

four or more crests on the molar teeth.

Characteristic animals are: Among Rodentia-Mylagauliclse, Mylagaulus, also a new and more specialized genus, Epigaulus Gidley; 

among Castoridse, Dipoides; among Carnivora, both Felinae and 

Machaerodontinse; among Canidae, dSlurodon, fDinocyon; among 

Rhinocerotidse, Teleoceras, Peraceras, Aphelops, including the progressive species A. malacorliinus; among Equidae, ProtoJiippus; 

among Artiodactyla, 4 families, (a) Dicotylidae, ProstJienops; (&) Camelidae, Procamelus, PliaucJienia (a large form), Alticamelus (typical 

in the Rattlesnake formation, Oregon); (c) Merycodontinae, Merycodus; (d) Cervidse, Blastomeryx; among Proboscidea, TrilopJiodon 

campester and T. euliypodon are recorded, both with long jaws.

16a. RATTLESNAKE FORMATION (200 FEET) OF JOHN DAY VALLEY, .OREGON.

(Figs. 1, 10; PI. I.)

The sparsely known fauna of this formation, as determined by 

Merriam, 6 Sinclair, and Gidley, contains the tortoise Clemmys 

hesperia Hay. 'Among mammals: Perissodactyla, (a) Equidae, PlioJiippus supremus, (&) Rhinocerotidae-?Teleocerinae, indet.; Artiodactyla, (a) Dieotylidae, indet., (6) Camelidae, Alticamelus altus (the 

typical form), also PliaucJienia; large species of Procamelus still 

survive.

PLIOCENE.

Homotaxis. Pliocene homotaxis must be prefaced by the statement that the American fauna is sparsely and imperfectly known as 

yet, and that correlations with Europe (Stages Messinien, Plaisancien, 

Astien) are very provisional. The gaps will undoubtedly be filled 

eventually.

" Seo Appendix, p. 115.

b A contribution to the geology of the John Day basin: Bull. Dept. Geology, Univ. California, 

vol. 2,1901, pp. 310-312.

56092 Bull. 361 09 ^6
82 CENOZOIC MAMMAL HORIZONS

VI. SIXTH FATTNAL PHASE.

Land connection with South America reestablished Invasion of South 

American Edentata-Gravigrada and Glyptodontia Migration of North 

American mammals to South America.

Decidedly distinct and more recent than either the typical "Loup 

Fork/' the upper "Loup Fork" deposits on Republican River, 

Kansas, or the Rattlesnake formation, is the Blanco formation of 

Texas.

MIDDLE PLIOCENE OR SECOND PHASE (EUROPE, ETAGE ASTIEN). 

17. BLANCO FORMATION; GLYPTOTHERIUM ZONE. 

' (Fig. 15; PI. I.) 

HOMOTAXIS.

North America. Plains fauna: 1, Blanco formation of Cummins," 

Cope,6 Gidley c (100 feet), Llano Estacado of Texas. 2, Ogalalla 

formation of Barton (? in part), northwestern Nebraska.

BLANCO "ROCK CREEK" "CLARENDON"

(middle Pliocene) (Equus zone, lower-Pleistocene) (upper Miocene)

PANHANDLE 

(middle Miocene)

.vJurassKjisa'n'dstbne';:'

FIG. 15. Diagrammatic section of the Staked Plains (Llano Estacado), Texas, showing the relations 

of the "Clarendon"(or Protohippus zone), "Rock Creek" (or Equus zone), and Blanco (or Glyptotherium zone) to the underlying "Panhandle" (or ? Merycochcerus zone). After J. W. Gidley, 1908.

FAUNA.d

This faunal phase is clearly characterized negatively: (1) By the 

undoubted extinction of the Oreodontidse, (2) by the apparent

extinction of the Rhinocerotidse, (3) by the apparent but not yet 

fully demonstrated absence "of the forest or browsing horse EypoJiippus. It is distinguished from the upper Pliocene of Europe (etage 

Sicilien) by being antecedent to the appearance of the genera Equus 

and Elephas. It is characterized very positively: In Texas (4) by the 

first appearance of South American Edentata-Gravigrada, Mylodon, 

Megalonyx; (5) also by the first appearance of Glyptodontia Glyptotherium; (6) in Texas and Nebraska by short-jawed Proboscidea with 

molar teeth in some respects resembling the Stegodon type, Dibelodon 

mirificus.

i Cummins, W. F., Notes on the geology of northwest Texas: Third Ann. Kept. Geol. Survey Texas, 

1891 (1892), pp. 129-200; Fourth Ann. Kept., 1892 (1893), pp. 179-238.

6 Cope, E. D., A preliminary report on the vertebrate paleontology of the Llano Estacado: Fourth 

Ann. Rept. Geol. Survey Texas, 1892 (1893), pp. 1-136.

c Gidley, J. W., The fresh-water Tertiary of northwestern Texas, etc.: Bull. Am. Mus. Nat. Hist., 

vol. 19, 1903 (Blanco), pp. G24-632.

<i See Appendix, p. 91.
OF WESTERN NORTH AMERICA. 83

The fossiliferous horizon on Loup River in Nebraska which 

yielded Dibelodon mirificus has not been recently explored. The 

fauna is sparsely known from the Blanco formation of Texas. ' It 

includes among Carnivora-Canidae, Borophagus, Amphicyon being 

doubtfully present; among Mustelidae, Canimartes; among Felicias, 

Felis Jiillianus, the earliest positively known appearance of Felis. 

Among Proboscidea from this level is Dibelodon mirificus (Nebraska, 

Texas); among Artiodactyla-Dicotylidae, the large cursorial peccary 

Platyqonus first appears; among Camelidae, PliaucJienia of very large 

size; amongEquidee, NeoJiipparion and Protoliippus continue; among 

Edentata-Glyptodontia, Glyptotherium resembles Panochtlius of the 

Pampean in type, but is less specialized; Megalonyx and Mylodon 

occur.

UPPER PLIOCENE OR LOWER PLEISTOCENE.

18. ELEPHAS IMPERATOR ZONE. 

HOMOTAXIS.

North America. 1, Horizon F of Hayden and Leidy, upper part 

only. 2, "Loup River" of Meek and Hayden, 1861-62, Nebraska. 

3, Certain formations (unnamed) in Texas and Mexico, containing 

Elephas imperator.

Europe. In Europe the uppermost Pliocene is distinguished by 

the disappearance of Hipparion and the advent of Elephas (E. meridionalis) and Eguus (E. stenonis).

HISTORY. AND SYNONYMY.

According to the decision of the committee on geologic names of 

the Geological Survey, the typical beds of this stage may for the present be known as upper Pliocene or Eleplias imperator zone. The 

ground for this decision is the confusion in the application of the terms 

"Loup River" and "Loup Fork," which apply to the same stream; 

also the confusion in the usage of the term "Loup Fork."

Horizon F, or the typical "Loup River beds," on "Loup Fork 

of Platte River, extending north to Niobrara River and south to 

an unknown distance beyond the Platte," were first characterized 

by Meek and Hayden a (1861-62) as follows: "Fine loose sand, with 

some layers of limestone contains bones of Oanis, 'Felis, Castor, 

Eguus, Mastodon, Testudo, etc., some of which are scarcely distinguishable from living species." Of the bones collected in this locality 

Leidy b observed in 1869: "Other remains of elephants, as Doctor Hayden supposes them to be, he observed in association with those of 

Mastodon mirificus, Equus excelsus, and Hipparion at the head of the 

Loup Fork branch of the Platte River; also between this point and

oProc. Acad. Nat. Sci. Philadelphia, vol. 13, 1861 (1802), p. 433. 

b Extinct mammalian fauna of Dakota and Nebraska, 1809, p. 255.
84 CENOZOIC MAMMAL HORIZONS

the Niobrara River and on the latter." These species were determined by Leidy as follows: Elephas imperator Leidy, Mastodon mirificus Leidy, Equus excelsus.

The type of Equus excelsus is elsewhere stated to be from the 'Tawnee Loup branch of the Platte or Niobrara River." In the same 

article a a somewhat fuller description of the "Loup River beds" 

makes them include all the deposits down to the top of the White 

River group, and the faunal list contains several Miocene genera in 

addition to the more modern types first cited.

The term "Loup River" was again employed by Hayden in 1862, 

1869 (introduction to Leidy's memoir), 1871, and 1873.

It is unfortunate that this upper Pliocene or lower Pleistocene horizon, although fairly well defined both geographically and f aunistically, 

should have been confused by Hayden and Leidy themselves (see 1869, 

pp. 15-21) with the very much older horizon or true upper Miocene, 

as part of their Horizon F, including the very rich upper Miocene 

faunal list. Thus Cope,6 while referring to the very same Nebraska 

fauna which was described by Leidy c in 1858, applies the terms "Loup 

Fork epoch" and "Loup Fork beds" to the "SantaFe marls" of New 

Mexico. The error thus spread into all the subsequent literature. 

It appears, therefore, that: (1) "Loup River" is the original name. 

(2) "Loup River" originally included an upper Pliocene or lower 

Pleistocene horizon. (3) "Loup Fork" is essentially the same name; 

it is a synonym of "Loup River;" it was defined in still another sense 

and has been generally used in a very different sense, and must drop

out of use entirely.

PLEISTOCENE.

VII. SEVENTH FAUNAL PHASE.

Increasing cold, moisture, and forestation Third modernization by a gradual Eurasiatic invasion of hardy, forest, fluviatile, mountain (alpine),

plains, and barren-ground fauna Gradual extinction of the larger TJngulata, of the native North American stocks, of the South American invading stocks, of the Miocene invading Eurasiatic and African stocks.

LOWER PLEISTOCENE (PREGLACIAL).

Our knowledge of the mammals in this period is still confined to 

the western plains and mountains.

The American Pleistocene begins either with the Elephas imperator 

zone (referred above to the upper Pliocene) or with the Equus zone. 

The exact position of the ElepJias imperator zone, also the question 

whether it is of the same age as the Equus zone, remain to be determined. In the present review only a few of the characteristic Pleistocene deposits will be included, because the subject of Pleistocene correlation and succession is in its infancy.

a Meek and Hayden, Proc. Acad. Nat. Sci. Philadelphia, vol. 13, 1861 (1862), p. 435. 

b Kept. U. S. Geog. Survey W. 100th Mer. (Wheeler), pt. 2,1877, pp. 20, 361. 

c Proc. Acad. Nat. Sci. Philadelphia, 1858, p. 20.
OP WESTERN NORTH AMERICA. 85 

19. EQTJUS ZONE. 

HOMOTAXIS.

America. Plains and border fauna. 1, "Sheridan formation" 

(Scott a) or, 2 ; Eguus zone, Hay Springs, northwestern Nebraska. 

3, "Rock Creek beds" (Gidley 6 ), Tule Canyon, Llano Estacado, 

Texas. Widely scattered and numerous deposits in Great Plains and 

Mountain regions, some of which have received distinct formation 

names.

Europe. Preglacial. Forest beds of Norfolk (England); St. Prest 

(Eure-et-Loire); Durfort (Gard), containing Eleplias meridionalis (its 

last appearance). The European fauna of this period includes 

(Osborn,c 1900) 12 Pliocene species, 32 Pleistocene species and races, 

now extinct, and 17 living species (7 Insectivora, 1 Cheiroptera.)

FAUNA.d

It is noteworthy (Matthew,6 1902) that chiefly the Plains fauna 

and no purely forest fauna of this phase is known, a fact which may 

account for the nonappearance of certain forest-living, types. There 

is some evidence of increasing moisture and of the renewal of streams 

and of forests; for example, at Hay Springs, northwestern Nebraska 

(a slightly earlier phase), the presence of streams is indicated by 

Fiber, of wooded rivers by Castoroides. In Silver Lake, Oregon (a 

slightly more recent phase), a partly fluviatile and wooded country is 

indicated by Fiber, Lutra, Castor, and Castoroides.

The mammal fauna e is characterized negatively (1) by the absence 

or disappearance of Perissodactyla-Rhinocerpticlse, (2) by the nonappearance of Bovidae or Ursidse. It is characterized positively by 

the first appearance (3) among Equidse, of Equus (3 species); (4) 

among Proboscidea, of ElepJias (2 species), E. colutnbi, E. imperator;f 

(5) among Artiodactyla, of the distinctively American genus Antilocapra; among Camelidae, of Camelus; among Rodentia, -of 6 new 

modern genera and the first appearance of the extinct Castoroides.

More in detail, among Rodentia of Nebraska and Oregon occur 8 

existing genera of the same region, Arvicola, Fiber, TJiomomys, 

Geomys, Cynomys, Castor, Lepus, and Castoroides; among CarnivoraCanidse, Canis (3 species); among Mustelidse, Lutra; among Felidae, 

Felis; among Edentata, Mylodon and Paramylodon ff (plains or river-

« Bull. Geol. Soc. America, vol. 9, 1898, p. 400.

bThc fresh-water Tertiary of northwestern Texas: Bull. Am. Mus. Nat. Hist., vol. 19, 1903, p. 022.

c Correlation, etc.: Ann. New York Acad. Sci., vol. 13,1900, p. 38.

d See Appendix, p. 91.

e Matthew, W. D., List of the Pleistocene fauna from Hay Springs, Nebraska: Bull. Am. Mus. Nat. 

Hist., vol. 16, art. 24, Sept. 25,1902, pp. 317-322. Cope, E. D., The Silver Lake of Oregon and its region: 

Am. Naturalist, vol. 23,1889, pp. 970-982.

/As noted on p. 83, E. imperator may represent a late Pliocene phase.

a Brown, Barnum, Bull. Am. Mus. Nat. Hist., vol. 19.1903. rm. 509-583.
86

border types); among Perissodactyla-Equinae, only 3 species; among 

Artiodactyla, 4 families: (a) Camelidse, Eschatius, Camelops (2 species), Camelus; (&) Dicotylidae, Platygonus; (c) Antilocapridae, Antilocapra (first appearance); (d) Merycodontinae (last appearance of 

this peculiarly American subfamily, genus Capromeryx) ; among Proboscidea, Elephas columbi, E. imperator. In the "Rock Creek beds" 

of Texas is found a supposed Dinocyon (BoropTiagus) or one of the 

Ursidae.

MIDDLE PLEISTOCENE (GLACIAL).

GENERAL CHARACTERS.

Our knowledge of the American mammals now for the first time 

becomes continental because it represents deposits in all parts of 

North America.

The general characters of the middle Pleistocene as a whole may 

'be summarized as follows:

1. This long period, which will eventually be divided into faunal 

substages, as in Europe, is distinguished negatively by the absence 

of the lower Pleistocene mammals (1) Elephas imperator and (2) Artiodactyla-Merycodontinae, and (3) by the gradual extinction of the 

resident large quadrupeds.

2. It is marked chiefly by the gradual invasion of a Eurasian hardy 

and boreal fauna and thus distinguished positively by the first recorded appearance (1) of Ursidae; (2) of Bovidae (a) Ovinae, (6) 

Bovinae, (c) Rupricaprinae; (3) of 3 genera of the larger northern 

Cervidae, namely, Alces, Odocoileus, Cervus (it is noteworthy that 

Rangifer does not appear in our mid-Pleistocene); (4) among Proboscidea, ElepTias primigenius and E. columbi succeed E. imperator, 

and the appearance of Mastodon americanus is first recorded.

3. The hardy forest and glade fauna both east and west increase

in number and variety, including the Cervidse and Ursidse.

4. The resident plains and forest-border grass-eating forms (Equidse, Camelidae, Elephantinae) diminish in number and gradually 

disappear.

5. Among all the larger Garnivora and Herbivora only 3 resident 

families, namely, the Canidse, Dicotylidae, and Antilocapridae, survive.

6. Thus all the less hardy previously invading Eurasiatic, South 

American, and native North American animals disappear.

7. Thus again we note the gradual extinction (1) among Edentata 

of the South American Gravigrada and Glyptodontia, (2) among 

Perissodactyla of the indigenous North American Tapiridse and 

Equidae, among Camelidae of Camelus, among Carnivora of the Machaerodontinae or saber-tooths; (3) among Eurasiatic forms of the Elephantinae.

8. The question of latitude, or more northerly or southerly distribution, becomes more important on account of the increasing cold.
OF WESTERN NORTH AMERICA. 87

The divisions of the mid-Pleistocene will ultimately be clearly 

marked off, first by the successive disappearance and extinction of 

the less hardy lower Pleistocene forms, second by the appearance or 

invasion of the more hardy modernized forms.

The following table is merely approximate:

Order of appearance and disappearance of lower Pleistocene forms.

APPEARANCE.

Early Pleistocene

Myloclon (central).

Paramyloclon.

Platygonus.

Elephas columbi.

Antilocapra.

Camelus.

Mid-Pleistocene.

Elephas primigenius.

Mastodon.

Odocoileus.-

Haploceras.

Erethizon.

Bison.

Alces.

Ovibos.

Cervus (late).

Ursus (late).

Rangifer (late).

DISAPPEARANCE.

Early Pleistocene.

Elephas imperator.

Caprorneryx.

?Paramylodon.

Mid-Pleistocene.

Camelus. 

Mylodon.

Megalonyx.

Tapir us. 

Arctotherium. 

Elephas columbi. 

Elephas primigenius.

Upper mid-Pleistocene.

Smilodontopsis. 

Mastodon. 

Equus. 

Mylohyus.

EABLY PHASES OF THE MIDDLE PLEISTOCENE.

The ear-liest phase, corresponding with the earliest mid-Pleistocene of Europe, is probably at present unrecognized in America. 

Other early phases of the middle Pleistocene may be provisionally 

distinguished as follows: (1) The true European stag Cervus does 

not appear; (2) the Camelidse, Equidae, Tapiridse, Edentata-Gravigrada, and Elephantidse still survive; (3) many extinct species of 

modern genera and many surviving modern species appear.

Port Kennedy cave, Pennsylvania. The Port Kennedy cave a has 

yielded 54 species of mammals, 40 of which are now extinct. From 

an analysis of its fauna, Barnum Brown b is inclined to place it in the 

early part of the mid-Pleistocene. The climate was apparently 

temperate. (1) It lacks the early Pleistocene genera Elephas and 

Camelus, but the latter has thus far not been found in eastern deposits 

at all. (2) Among surviving lower Pleistocene forms it includes (a) 

of the Machserodontinae, 2 species; (b) of the Edentata, 2 genera,

a Mercer, H. C., The bone cave at Port Kennedy, Pennsylvania: Jour. Acad. Nat. Sci. Philadelphia, 

vol. 11, pt. 2,1899.

6 Brown, Barnum, The Conard fissure, a Pleistocene bone deposit in northern Arkansas: Mem. Am. 

Mus. Nat. Hist., vol. 9, 1908, pp. 157-208.
88 CENOZOIC MAMMAL HOKIZONS

Megalonyx, Mylodon; (c) of the Perissodactyla, Equus, 2 species, 

Tapirus; (d) of the Dicotylidse, Mylohyus. (3) Among newly entering northern forms are: (a) Odocoileus; (&) Ursus, 2 species; (c) 

Erethizon (the first recorded appearance- of the Hystricomorpha in 

North America). (4) We note the absence of Bovidae.

Twelvemile Creek, Kansas. On the plains of western Kansas, in 

Logan County, on Twelvemile Creek, a tributary of Smoky Hill 

River, is a deposit formerly considered by Williston 0 as of lower 

Pleistocene age, but now known to be of mid-Pleistocene age. In 

the blue-gray marl underlying the recent plains marl are recorded 

ElepJias primigenius (?E. columbi), Platygonus compressus, and a number of specimens of Bison occidentalis (Lucas). Among Primates, 

Homo is indicated 6 by the occurrence of an arrowhead certainly 

associated with the skeleton of Bison occidentalis and believed by 

Williston to be in situ'.

SUBSEQUENT PHASES OF THE MIDDLE PLEISTOCENE. 

HOMOTAXIS.

America. Potter Creek cave, Shasta County, Cal.; Silver Lake, 

Oregon.

ENVIRONMENT.

Environmental conditions on the Pacific coast were quite different 

from those in the Middle and Eastern States: (1) All glaciation on 

the Pacific coast was comparatively late in the Pleistocene and of the 

alpine type (Sinclair). It is quite possible, therefore, that many 

types of mammals (elephants, mastodons, camels, bisons) survived 

in the comparatively mild climate of the Pacific coast after they had 

become extinct in more easterly regions.

FAUNA.

Potter Creek cave. The very rich Potter Creek cave fauna is 

regarded by Merriam and Sinclair c as a late phase of the middle 

Pleistocene, or even as late as the last quarter of the Pleistocene. It 

contains 37 genera and 49 species of mammals, of which 8 genera and 

22 species are extinct, 3 are doubtfully extinct, and 21 are still existing. It is chiefly a forest fauna; forest types are numerous and 

plains types are lacking.

Positively we note the survival or presence of the edentates Megalonyx and Notoiherium; also of Equus and Elephas. Among Artioa Williston, S. W., The Pleistocene of Kansas: Univ. Geol. Survey Kansas, vol. 2,1897, p. 300.

6 Williston, S. W., On the occurrence of an arrowhead with bones of an extinct bison: Trans. Intern. 

Congress of Americanists, 1902, p. 335.

c Sinclair, W. J., A preliminary account of the exploration of the Potter Creek cave, Shasta County, 

Cal.: Science, n. s., vol. 17, No. 435, May 1,1903, pp. 708-712. The exploration of the Potter Creek cave: 

Univ. California, Publ. Am. Arch, and Eth., vol. 2, No. 1, 1904, pp. 1-27. New Mammalia from the 

Quaternary caves of California: Bull. Dept. Geology, (Jniv. California, vol. 4, 1905, pp. 145-161.
OF WESTERN NORTH AMERICA. 89

dactyla-Cervidse, the typical American deer Odocoileus is abundant. 

Negatively we note the absence or disappearance of PerissodactylaTapirus, of Carnivora-Machaerodontinae; these absences may have 

been due to local conditions; the machaerodonts are frequently associated with a Plains fauna, as in the California asphaltum deposits. 

The nonappearance of the genus Cervus as well as of RodentiaHystricomorpha is significant.

A large number of new types appear. Among primates the presence of Homo is indicated, in the opinion of certain anthropologists 

(Putnam), by supposed bone implements; others (Merriam0) regard 

this evidence as inconclusive. Among Carnivora-Ursidae, remains of 

Ursus and Arctotherium are very numerous; among Felidae, Felis (a 

species of large size), Lynx; among Canidae, Urocyon, Vulpes, Canis; 

among Mustelidae, Taxidea, Mephitis, Spilogale, Putorius; amongProcyonidse, Bassariscus; among Rodentia, 17 existing species; 

among Artiodactyla, (a) Dicotylidae, Pktygonus (a doubtful determination); among (6) Cervidae, Odocoileus; among (c) Bovidse, Bison; 

among (d) Rupricaprinae, Haploceras; among (e) Ovinae, Euceratlierium b (related to Ovibos); among (/) Camelidae, Camelus; among 

Edentata, Megalonyx (a forest and foothill edentate), 4 species; 

among Perissodactyla-Equidae, Eguus, 2 species; among Proboscidea, 

Mastodon (its first appearance, the species at present indeterminate), 

Eleplias primigenius (f E. columbi).

Washtuckna Lake, Washington.0 Of about the same age are the 

deposits of Washtuckna Lake, Washington, a forest, mountain, 

and open-country fauna, imperfectly known. Among CarnivoraMustelidae, Taxidea; among Felidae, Felis concolor, F. canadensis; 

among Edentata, Mylodon; among Perissodactyla-Equidae, Eguus; 

among Artiodactyla-Cervidae, Alces, 2 species, Odocoileus, 1 species; 

among Camelidse, Camelus,-3 species; among Rupricaprinee, Haploceros.

Samwel cave, California. In Samwel cave, Shasta County, Cal., 

is found (Furlong d] a fauna much more recent than that of the 

Potter Creek cave, including Preptoceras (with affinities to Ovibos 

and closer affinities to Euceratherium). Among Rodentia the Hystricomorpha appear; among Artiodactyla-Cervidse, Odocoileus; among 

the absent or nonrecorded forms, Ursidae, Arctotherium.

a Merriam, J. C., Recent cave exploration in California: Am. Anthropologist, April-June, 1906, p. 221.

6 Sinclair, W. J., and Furlong, E. L., Euceratherium, a new ungulate from the Quaternary caves of 

California: Bull.Dept. Geology, Univ. California, vol. 3, 1904, pp. 411-418.

e Matthew. W. D., List of the Pleistocene fauna from Hay Springs, Nebraska: Bull. Am. Mus, Nat. 

Hist., vol. 21, 1902, pp. 321-322.

d Furlong, E. L., The exploration of Samwel cave: Am. Jour. Sci., 4th ser., vol. 22, Sept., 1900, pp. 

235-247. 
90 CENOZOIC MAMMAL HORIZONS OP WESTERN NORTH AMERICA. 

LATE PHASE OF THE MID-PLEISTOCENE.

The Conard fissure of Newton County, Ark.,a contains a typical 

forest fauna that lived in a region with open glades similar to the 

present landscape. It is very rich in individual specimens. Of the 

37 genera and 51 species of mammals represented, 4 genera and 24 

species are now extinct.. Twenty genera and 6 species which occur, 

in the Port Kennedy cave are also found here. Of the surviving 

species many are now distinctly northern or boreal types, such as 

Microsorex, Mustela americana, Erethizon dorsatus, Cervus canadensis. 

There are also 7 species of amphibians and reptiles and 7 species of 

birds.

The Proboscidea, Edentata, Tapiridae, and Camelidae of the earlier 

Pleistocene faunae have all disappeared or are not represented. 

Only Equus and a machaerodont (Smilodontopsis) survive. There is 

no evidence of Homo.

Among Garnivora, (1) Ursidae ( Ursus) are numerous; (2) among 

Felidae-Felinas, Felis, subgenus Lynx; among Machaerodontinae, 

Smilodontopsis (Brown), a surviving saber-tooth; (3) among Canidae, 

Canis, Vulpes, and Urocyon; (4) among Mustelidse, Mephitis, Spilogale, Brachyprotoma (an extinct skunk, also found in the Port Kennedy cave fauna), Mustela, and Putorius; (5) among Procyonidae, 

Procyon; among Insectivora, Blarina, Sorex, ^Microsorex, Scalops; 

among Cheiroptera, Vespertilio and Myotis; among Rodentia, Lepus, 

Microtus, Fiber, Neotoma, Reithrodontomys, Peromyscus, Castor, Geomys, Spermophilus, Tamias, Sciurus, Arctomys, and the hystricomorph 

Erethizon; among Artiodactyla-Dicotylidae, Mylohyus; among Cervidae, Odocoileus; among Equidaa, Equus (represented by a single 

tooth); among Bovidae ?, the aberrant musk ox, Symbos.

CONCLUSION. /

The conclusion is that North America promises to give us a nearly 

complete and unbroken history of the Tertiary in certain ancient 

regions, which are, after all, comparatively restricted. The middle 

and upper Eocene is approaching solution, but the lower and basal 

Eocene still require additional surveys. The chief remaining gap is 

now in the Pliocene stratigraphy, which calls for very exact geologic 

sectioning and most careful systematic or faunistic comparisons.

Materials are at hand for an establishment of the Pleistocene 

sequence, which will be of the greatest aid to geologists. Here especially the paleontologist must work with the greatest caution in the 

identification and description of species. It would be easy by careless methods to separate two depositions which are actually closely 

similar in age.

a Discovered in 1903 by Mr. Waldo Conard. The fauna was explored in 1903-4 and described by Barnum Brown in 1908: Mem. Am. Mus. Nat. Hist., vol. 9,1908, pp. 157-208.
APPENDIX.

FAUNAL LISTS OF THE TERTIARY MAMMALIA OF THE

WEST.

By WILLIAM DILLEH MATTHEW.

BASAL EOC'ENE.

FIRST PHASE PUERCO.

Polymastodon zone. 

1. San Juan basin, New Mexico.

SECOND PHASE TORKE.ION.

Pantolambda zone.

1. San Juan basin, New Mexico.

2. Fort Union formation (in part), Montana.

MULTITUBE11CULATA.

PLAGIAULACID^E. 

1.

Neoplagiaulax americanus Cope... 

Catopsalis foliatus Cope............

Polymastodon taoensis Cope.......

Polymastodon attenuatus Cope....

Polymastodon selenoclus 0. and E.

X Neoplagiaulax molestus Cope.. 

Ptilodus'mediavv'us Cope......

Ptilodus trovessartianus Cope. 

Pohinastodon flssidens Cope..

1. 2,

Triisodon quivirensis Cope... 

Triisodon heilprinianus Cope. 

Triisodon gaudrianns (Cope).

Oxyclsenus cuspidatus Cope ........

Oxyclfenus simplex (Cope) .........

Loxolophus hyattianus (Cope)......

Loxolophus priscus (Cope)..........

Loxolophus attenuatus 0. and E... 

Carcinodon filholianus (Cope).......

Paradoxodon rutimeyeramis (Cope).

J30LODONTIMC.

|| Chirox plicatus Cope. 

CREODONTA.

-I X I

Didymictis haydenianus Cope........... | X I

ARCTOCYONID^E.

Clamodon corrugatus (Cope)......

Chcnodon ferox (Cope)............

?Cl£enodon protogonioides (Cope)

MESONYCHID^E.

Dissacus navajovius Cope .............. I X

Dissacus saurognathus Wortman....... I X

TKIISODONTID^E.

Sarcothraustes antiquus Cope........

Goniacodon levisanus Cope...........

Microclaaiodon assurgens Cope ......

Chriacus polvidens (Cope)......

Chriacus bald win! Cope.........

Chriacus truncatus Cope.......

Chriacus schlosserianus Cope... 

Tricentes subtrigonus (Cope)... 

Tricentes crassicollidens Cope.. 

Delta thorium fimdaminis Cope.

o Part or all of this family may be referable to the Insectivora, according to Wortman.

91
92 CENOZOTC J&EAMMAL HORIZONS

BASAL EOCENE Continued. 

INSECT! VOB A.

? HYOPSODONTIDvE. 

1.

Mioclaenus turgidunculus Cope.

Oxyacodon apiculatns 0. and E. 

Oxyacodon agapetillus (Cope)..

X Mioclsenus turgiclus Cope.......

Mioclaenus lemuroidcs Matthew 

MioclfEnus acolytus Cope.......

Mioclsenus lydekkerianus Cope. 

Mioclsenus inaBquidens (Cope).. 

?Protosolene opisthacus (Cope).

INCERTVE SEDIS.

ANTOLESTID.E.

|| Pentacodon in versus Cope.

Mixodectes pungens Cope. .......

Mixodectes crassiusculus (Cope) . 

Indrodon malaris Cope. .........

1. 2

TJENIODCHSTTA.

STYIJNODONTID^E. 

Wortmania otariidens Cope................... | X || Psittacotherium multifragum Cope...... | X I

CONORYCTID^E.&

Onychodectcs tisonensis Cope. 

Onychodectes rams 0. and E.

Conoryctes comma Cope.

CONDYLARTHRA.

PHENACODONTID^E.

?Protogonodon pentacus Cope.........

?Protogonodon stenognathus Matthew.

Tetraclaenodon puercensis (Cope). 

Tetraclajnodon minor (Matthew).

Periptychus coarctatus Cope.......

Ectoconus ditrigonus (Cope).......

Conacodon entoconus (Cope)......

Conacodon cophater (Cope)........

Anisonchus gillianus Cope.........

Hemithlseus kxnyalevsManus Cope.

AMBLYPODA.

PEEIPTYCHID.E.C

Periptychus carinidens Cope... 

Periptychus rhabdodon (Cope). 

H.aploconus lineatus Cope......

Baploconus corniculatus Cope. 

Anisonchus sectorius Cope.....

PANTOLAMBDID.E.

Pantolambda bathmodon Cope. 

Pantolambda cavirictus Cope..

LOWER EOCENE.

FIRST PHASE WASATCH. 

Coryphodon zone.

1. Typical Wasatch, Evanston, Wyoming.

2. Black Buttes, Washakie liasin, Wyoming.

3. Bighorn Valley, Wyoming.

4. San Juan basin, New Mexico.

SECOND PHASE WIND RIVER. 

Lambdotherium and Bathyopsis zones.

1. AVind River basin, Wyoming.

2. Lower Huerfano. Colorado.

Pelycodus jarrovii Cope.........

Pelycodus tutus Cope...........

Pelycodus frugivorus Cope......

PRIMATES.

NOTHARCTID^E. 

1. h2. 3. 4.

X Pelycodus sp....................

Notharctus nunienus Cope......

Notharctus venticolus Osborn.. 

Notharctus palmeri Loomis. 

Notharctus cingulatus Loomis..

a Order Proglires of uncertain relationship, according to Osborn.

i> ?Insectivora.

.< Auct. Osborn; Condylarthra according to Matthew.
OF WESTERN NORTH AMERICA. 93

LOWER EOCENE Continued. 

PRIMATES Continued.

AN APTOM ORPHlDjE .

Anaptomorphus homunculus 

Cope...........................

Anaptomorphus m i n i m u s 

Loomis........................

1. 2. 4.

Anaptomorphus spierianus Cope.........

abbot! Loomis..........

? Omomys ("Notharctus") minutus 

Loomis.................................

Anaptomorphid gen. indesc..............

Cynodontomys latidens Cope ... 

Cynodontomysangulatus (Cope)

MICROSYOPIM:."

X Cynodontomys sp.

X II Microsyops scottianus Cope. 

CARNIVORA (CREODONTA).

Didymictis protenus (Cope). 

Didymictis leptomylus Cope. . . .

Viverravus cf. dawkinsianus 

(Cope) ........................

Miacis sp .......................

Uintcacyon inassetericus (Cope) . 

Vassacyon proinicrodon ( W. and

Vulpavu scf . brevirostris(Cope) . 

Vulpavus sp .................... X

Didymictis altidens Cope........

Didymictis leptomylus Cope. 

Viverravus dawkinsianus (Cope). 

Miacis sp.........................

06'dectes sp......................

Vulpavus canavus (Cope)........

Vulpavus brevirostris (Cope)

Anacodon ursidens Cope.

? ARCTOCYONID-ffi:.

-I I I X I |l 

PAL;EONICTID/E (=AMHLOCTONID^E).

Palaxmictis occidentalis Osborn. 

Ambloctonus sinosus Cope......

Oxyjena lupina Cope.... 

Oxyama forcipata Cope.. 

Oxyaena morsitans Cope.

Sinopa viverrina (Cope).........

Sinopa strenua (Cope).....:....

Sinopa multicuspis (Cope)......

Sinopa hians (Cope).............

Sinopa opisthotoma Matthew...

Pachyrana ossifraga Cope.......

Pachyiena gigantea Osborn.....

Pachyacna intermedia Wortman. 

LTaptilodcctesleptognathus (OSborn)*'.........................

X

c

y xs

n

X II

X

V*\

Oxysena huerfanensis Osborn ............

Oxyajna sp ...............................

Patriofelis tigrinus (Cope) ...............

Tjimnnnvon sn

V/N

V

HYyiCNODONTID^E.

7

x

x

y ^

X

X

Sinopa sp ................................

Tritemnodon whitia3 (Cope) .............

V /\

MESONYCHIM:.

X

X

X

X Pflchysena cf. gigantea c. .................

Hapalodectes sp. indesc. ....... ..........

X

Vx\

Palteosinopa veterrima Matthewj |

Palfeictops cf. bicuspis.

INSECTIVORA.

PANTOLESTID^E.

a

| x I || Pahcosinopa didelphoides (Cope)........| x |

LEPTICTID^E. 

.| ' I | X I .11 Palfeictops bicuspis (Cope)..............| X I

HYOPSODONTID^E.

Hyopsodus miticulus (Cope).. 

Hyopsodus lernoinianus Cope. 

Hyopsodus powellianus Cope . 

Hyopsodus laticuneus (Cope). 

Hyopsodus simplex Loomis...

Diacodou alticuspis Cope.......

Diacodon celatus Cope.........

Didelphodus absaroka; Cope e..

,

v

y

Hvopsodus so ............................

V

v

v

Y

INCERTVE SEDIS.

''Peratherium" comstocki Cope. 

X 

X

a ?=Mixodectid8B (Insectivora). . . .

6Qen. nov. Type, Uintacyon promicrodon W. and M., 1899. Differs from Uintucyon in broad basinheel of lower carnassial and other characters.

cAuct. F. B. Loomis in lit.

<i Gen.nov. Type, Dissacun leptognathus, Osborn and Wortman, Bull. Am. Mus. Nat. Hist., vol. 4, 

p. 112, tig. 10.

« Probably Insectivore, auct. .1. L. Wortman.
94 CENOZOIC MAMMAL HORIZONS

LOWER EOCENE Continued.

TILLODONTIA.

? ANCHIPPODONTID^E. 

1. 2. 3. 4.

Esthonyx burmeisteri Cope.. 

Esthonyx acer Cope..........

Esthonyx bisulcatus Cope....

Esthonyx spatularius Cope..

Paramysprimsevus Loomis.. 

Paramys qiiadratus Loomis . Paramys atwateri Loomis... 

? Sciuravus buccatus (Cope).

Calamodon simplex Cope........

Calamodon arcamcenus Cope.... 

^Calamodon noyomehicanus Cope 

"Ectoganus gliriformis Cope.....

Dryptodon crassus Marsh.......

X Esthonyx acutidens Cope... 

Esthonyx spatularius Cope.

RODENTIA.

ISCHYROMYIDjE.

Paramys bicuspis Loomis... 

Paramys copei Loomis......

Paramys major Loomis.....

Paramys excavatus Loomis. 

Sciuravus depressus Loomis.

T^ENIODONTA.

STYLINODONTID/E.

Stylinodon ciylindrifer (Cope).

Phenacodus primaevus Cope. 

Phenacodus nunienus Cope.. 

Phenacodus hemiconus Cope 

Phenacodus astutus (Cope)" 

Phenacodus flagrans (Cope) 

Phenacodus brachypternus Cope 

Phenacodus macropternus Cope. 

?Phenacodus sulcatus Cope 6....

Eohyus distans Marsh..........

Eohyus robustus Marsh.........

Eetocion osbornianus Cope......

Meniscotherium terrserubrfe

Cope.

Meniscotherium chamense Cope. 

Meniscotherium tapiacitis Cope..

CONDYLARTHRA.

PHENACODONTIM:. 

X Phenacodus wortmani Cope. 

Phenacodus sp..............

Eetocion cf. osbornianus....

MENISCOTHERIID^E. 

X

AMBLYPODA.

CORYPIIODONTID/E.

Coryphodon testis Cope. ........

Coryphodon lobatus Cope. . .....

Coryphodon elephantopus Cope. 

Coryphodon hamatus Marsh. ... 

Coryphodon latidens Cope ...... 

Coryphodon curvicristis Cope. . . 

Coryphodon armatus Cope. . ....

X

X

vA

V A

X 

X

X

V/N

X 

X

Coryphodon ventanus Osborn.. 

Coryphodon wortmani Osborn.. 

?Coryphodon singularis Osborn.

Heptodon posticus Cope 

Heptodon singularis (Cc

Systemodon tapirinus (Cope)...

Systemodon protapirinus Wortman ...........................

Systemodon primoevus Wortman. ..........................

Systemodoii semihians Cope....

UlNTATHERIIDvE).

Bathyopsis flssidens Cope. 

PERI S S OD ACT Yt, A.

LOPHIODONTIDjE.

Heptodon ca,lciculus Cope. 

Heptodon ventorum Cope.

« P. wortmani Cope in part, blncertaj sedis.
OF WESTERN NORTH AMERICA. 95

LOWER EOCENE Continued.

PERI 8 8 OD ACT YL A Continued.

EQUID^E. 

1. 2. 3. 4.

Eohippus pernix Marsh........

Eohippus validus Marsh.......

Eohippus yasacciensis (Cope).. 

Eohippus index (Cope).........

Eohippus angustidens (Cope).. 

Eohippus cuspidatus (Cope)... 

Eohippus cristatus (Wortman) 

Eohippus cristonensis (Cope).. 

Eohippus montanus Wortman. 

Eohippus borealis Granger. 

Eohippusresartus Granger.....

X Eohippus venticolus (Cope)... 

Eohippus craspedotus (Cope).

1. 2.

TlTANOTHERIID^E ( = BRONTOTHERIIDvE).

Lambdotherium popoagicum Cope. 

Eotitanops borealis (Cope)........

Eotitanops brownianus (Cope)....

ARTIODACTYLA.

TRIGONOLESTID^E (=? DlCHOBUNID^E).

Trigonolestes brachystomus 

(Cope).........................

Trigonolestes chacensis (Cope).. 

Trigonolestes nuptus (Cope)..:. 

Trigonolestes metsiacus (Cope) . 

Helohyus etsagicus (Cope)......

Trigonolestes secans Cope. X X

? ACH.ffiNODONTID.iE.

Parahyus vagus Marsh.... 

Parahyus aberrans Marsh.

MIDDLE EOCENE.

FIRST PHASE BRIDGER (LOWER PART). 

Orohippus zone.

1. Lower Bridger (horizon B), Wyoming.

2. Upper Huerfano, Colorado.

SECOND PHASE BRIDGER ( UPPER PART). 

Uintatherium zone.

1. Upper Bridger (horizons C and D), Wyoming.

2. Washakie Basin, Wyoming.

Pelycodus sp..................

Notharctus tenebrosus Leidy. 

Notharctus rostratus (Cope). 

Notharctus aflmis (Marsh)... 

Notharctus anceps (Marsh)...

PRIMATES.

NOTHARCTID.E. 

1. 2.

Notharctus tyrannus (Marsh)...........

Telmatolestes crassus Marsh............

Notharctus aut Telmatolestes sp. div...

1. 2.

ANAPTOMORPHID^E.

Omomys carter! Leidy.........

Omomys pucillus. (Marsh).....

Omomys ameghini Wortman.. 

Euryacodon lepidus Marsh....

Anaptomorphus femulus Cope.

X 

X 

X 

X 

X ? Anaptomorphus sp...................' X

? Smilodectes gracilis (Marsh) ............ |

Hemiacodon gracilis Marsh..............' X

Hemiacodon pygmajus Wortma n........ X

Washakius insignis Leidy............... X

Washakius sp........................... X

MICROSYOPIDJE.

Microsyops elegans (Marsh). 

Microsyops typus (Marsh).. 

Microsyops sp..............

«Incertte sedis,

Microsyops annectens (Marsh).. 

Microsyops schlosseri Wortman. 

Microsyops sp...................

f>?=M.ixodectid8e (Insectivora).
96

MIDDLE EOCENE Continued.

CARNIVORA (CREODONTA).

MlACID*.

Harpagolestes macrocephalus Wortntan..

I]

Nyctilestes serotinus Marsh. .............

Gen. et sp. indesc.........................

Gen. et sp. indesc. . .......................

l.

X 

X 

X 

X 

X ? 

? 

X 

X 

X 

X 

X

0

X

X 

X 

X 

X

HY^

X 

X

?

X 

X 

X

ME

X 

X

srsi

Al

?

X 

X 

X 

X

?( 

? ]

HYI

X 

X

PA

X 

X

2.

X\T JE

1 X

ENOE 

SON1

3CT

'ATE

TAL 

DENT

uEPT

)PSOI 

NTOL

Miacis hargeri (Wortman) ........

NIDJE.

.

ONTID^E.

fCHIDJE.

Synoplotherium lanius Cope 6 ...........

IVORA.

HYIO^E.

Apateinys bellulus Marsh ......... ...

Gen. et sp. indesc. ............... .

Gen. et sp. indesc .............. . .

PIDiE.

Talpavus nitidus Marsh. .

Nyctitherium velox Marsh.

Gen. et sp. indesc. ................

Gen. et sp. indesc ...................

Gen. et sp. indesc ...................

Gen. et sp. indesc. .......................

ETIDJE.

ICTID-E.

lONTID^E.

ESTHXE.

Pantolestes cf . loneicaudns ..............

1.

X 

X 

X 

X

V

X 

X

X

X 

X

X

?

X

X 

X 

X 

X 

X

X 

X 

X 

X 

X 

X 

X 

X

X 

X 

X

X 

X 

X 

X

X 

X 

X

X 

: X ' y

a" P. ulta Leidy," Os'oorn, Bull. Am 

P. ulta of Leidy. 

.6 Including Dromocyon vorax Marsh.

Mus. Nat. Hist., 1897, p. 250; idem, 1900, p. 278, fig. 8. Not
OF WESTERN NORTH AMERICA. 97

MIDDLE EOCENE Continued. 

TILLODONTIA.

'ANCHIPPODONTHXE. 

I 1. 2.

Trogosus castoridcns Leidy «. 

Trogosus minor Marsh........

? Tillotherium sp.............

Tillotherium fodiens Marsh. 

Tillotherium hyracoides Marsh. 

Tillotherium latidens Marsh....

1. 2.

RODENTIA.

ISCHYROMYIDJE.

Paramys delicatus Leidy.................

Paramys delicatior Leidy.. ..............

Paramys delicatissimus Leidy...........

Paramys sp. diy..........................

Pseudotomus hians Cope..... .........

Pscudotomus robustus (Marsh).... ....

Pseudotomus supcrbus (O., S., and S.)..: 

Pseudotomus sp. div........ .............

Sciuravus nitidns Marsh..................

Sciuravus undans Marsh.................

Sciu ravus parvidens Marsh...............

Sciuravus minimus (Leidy)...............

Sciuravus sp. div........................

Tillomys parvus Marsh...................

Paramys leptodus (Cope). 

Paramys sp. div..........

Pseudotomus sp. div.....

Sciuravus sp. div.........

Colonomys celer Marsh... 

Taxymys lucaris Marsh... 

Tillomys senex Marsh....

Stylinodon minis Marsh.

TVENIODONTA.

STYLINODONTID.E. 

---I ? I II

EDENTATA.

METACHEIROMYIDjE.

Metacheiromys marshi Wortman. 

Metacheiromys dasypus Osborn.. 

Metacheiromys tatusia Osborn...

Metacheiromys s'p.

AMBI/TPODA.

? Uintatheriuin sp.

=UINTATHERHDA:).

Uintatherium robustum Leidy.........

Uintatherium latifroiis Marsh..........

Uintatherium leidyanum 0., S., and S... 

Uintatherium spierianum (S. and O.) t>. 

U. (Dinoceras) mirabile Marsh..........

U. (Dinoceras) agreste Marsh...........

U. (Dinoceras) laticeps Marsh...........

U. (Dinoceras) lucare Marsh............

U. (Tinoceras) anceps Marsh...........

U. (Tinoceras) crassifrons Marsh.......

U. (Tinoceras) hians Marsh.............

U. (Tinoceras) grandis Marsh...........

U. (Tinoceras) ingens Marsh............

U. (Tinoceras) longiceps Marsh........

U. (Tinoceras) pugnax Marsh...........

U. (Tinoceras) stenops Marsh...........

U. (Tinoceras) vagans Marsh...........

U. (Tinoceras) afiinis Marsh.. .........

U. (Tinoceras) aunectens Marsh.........

PEKISSODACTYLA.

HYRACODONTIDjE.

Hyrachyus agrarius Leidy............. .

Hvrachyus sp. div......................

? Hyrachyus bairdianus (Marsh)........

Hyrachyus paradoxus O., S., and S .....

Colonoceras agrestis Marsh..............

Hyrachyus cximius Leidy:.............

Hyrachyus intermedius O., S., and S... 

Hyrachyus crassjdens 0., S., and S.....

Hyrachyus prineeps Marsh..... .......

Hyrachyus imperialis O., S., a,nd S.....

Hyrachyus sp. div......................

Triplopus cubitalis Cope................

" Triplopus " amarorum Cope..........

"Identified by Leidy with Anchippodus vetulus from a Tertiary formation in New Jersey. The 

type of A. vetulus is indeterminate generically, and it is not certain that it belongs to the same family 

as Trogosus and Tillotherium. I retain Trogosus us distinct in order to avoid a misleading correlation.

6 This species may belong to the upper " Washakie " level, and to the genus Eobqsileus,

56092 Bull. 361 09 -7 . -
98 CENOZOIC MAMMAL HORIZONS

MIDDLE EOCENE Continued. 

PERISSODACTYLA Continued.

LOPHIODONTID-ffi. 

1. 2.

Helaletes boops Marsh.. 

Helaletes nanus (I/eidy). 

Helaletes sp. div......"..

Helaletes sp. .div...............

Desmatotherium guyoti Scott. 

Pilophodon minusculus 'Scott.

1. 2

? Isectolophus modestus (Leidy).

TAPIRID2E.

.1X1 || Isectolophus latidens (S. and O.)........| x

Orohippns pumilus (Marsh)... 

Orohippus ballardi (Marsh)....

Orohippus procyoninus (Cope). 

Orohippus major Marsh.......

Orohippus cinctus (Cope)......

Orohippus osbornianus (Cope).

Orohippus sylyaticus (Leidy). 

Orohippus agilis Marsh.......

Orohippus uintanus (Marsh).

Pateosyops paludosus Leidy. 

Palseosyops major Leidy......

Palaeosyops fontinalis Cope.. 

Limnohyops laticeps Marsh.. 

Palseosyopinse sp. div........

= BRONTOTHERIID^:).a

Palaeosyops humilis Leidy..............

Palaeosyops robustus Marsh.......... . Limnohyops diacomis Cope.............

Telmatherium validum Marsh. ........

Telmatherium cultridens S. and 0 ......

Tclmatherium hyognathum S. and O....

Telmatherium megarhinum Earle....

Telmatherium vallidens (Cope)..........

Manteoceras manteoceras (Osborn).....

Palaeosyopinse sp. div...................

ARTIODACTYLA.

H.OMACODONTID.S:

Homacodon sp. aff. vagans.. 

Microsus cuspidatus Leidy... 

Sarcolemur pygmeeus (Cope). 

Sarcolemur furcatus Cope.... 

Nanomeryx caudatus Marsh. 

Helohyus plicbdon Marsh.... 

Helohyus sp. div.............

Homacodon Vagans Marsh..............

? Stenacodon rarus Marsh...............

Helohyus lentus (Marsh)................

Helohyus validus (Marsh)...............

Helohyus sp. div......... ............ .

? Ithygrammodon cameloides O., S., and 

S.......................................

TIPPER EOCENE.

FIRST PHASE. SECOND PHASE TRUE UINTA. 

Eobasileus zone. . Diplacodon zone.

1. Washakie Basin, Wyoming (upper beds).

2. Uinta Basin, Utah (horizons A and B).

3. ? Sage Creek, Montana.

4. ? Uppermost Bridger (horizon E), Wyoming.

1. Uinta Basin, Utah (horizon C).

1. 2.

PRIMATES.

NOTHARCTID.ffi. 

3. 4.

Notharctus uintensis (Osborn).. X ?

CARNIVORA (CREODONTA).

MlACID^E.

Miacis uintensis Osborn. Miacis vulpinus S. and O..................... X

Miacis uintensis Osborn...................... X

? Uintacyon scotti (W. and M.)..............| ?

Oxysenodon dysodus Matthew .. 

Thinocyon sp. indesc ............ X

Oxyaanodon dysclerus.Hay.................. X

Limnocy on sp. indesc........................ X

MESONYCHUXE.

X

Harpagolestes uintensis (S. and Harpagolestes uintensis (S. and O.).

O.).............................

Harpagolestes sp. indesc........

Mesonyx sp.....................

<i The Eocene titanotheres will be revised and the list of genera and species considerably extended in 

Professor Osborn's forthcoming monograph on the family.

* See Stehlin, Saugetbiere des schweizerischen Eocans, IV. Th., Abhandl. Schw. pal. Ges., vol. 23, 

1906, p. 669, for inclusion of Homacodon and related genera in the Dichobunidse. The reference of Microsus and Sarcolemur to Mis group is based on comparison with Homacodon.
OF WESTEEN NORTH AMERICA. 99

UPPER EOCENE Continued.

CARNTVORA (FISSIPEDIA).

CANID.E.

1.

Procynodictis vulpiceps W. and M........... X

INSECTIVORA.

HYOPSODONTID^E.

Hyopsodus gracilis Marsh.... 

Hyopsodus uintensis Osborn.

RODENTIA.

ISCHYROMYIDJE.

Paramys uintensis Osborn. . ....

1.

X

2.

X

X

3. 4. t

Paramys sciuroides S. and 0 .................

Paramys sp. div. ............................

Pseudotomus so. div. ........................

X 

X 

X

? GEOMYIDJE.

|| Protoptychus hatcheri Scott.................| X

AMBLYPODA.

EOBASILEID^E.

Eobasileus cornutus Cope.......

Eobasileus furcatus Cope.......

Eobasileus pressicornis Cope... 

Eobasileus galeatus (Cope).....

Eobasileus sp. div..............

PERISSODACTYLA.

HYRACODONTIDJE.

llyrachyus priscus Douglass.... 

Hyrachyus sp. div..............

Triplopus obliquidens (S. and O.).

AMYNODONTJDJE.

Aniynodon autiquus (S. and 0.). 

Araynodon sp...................

" Metamynodon " sp. (=? Amynodon)......................... X

Amynodon advenus Marsh.. 

Auiynodon intermedius S. and O.

" Heptodon " ? sp. (=? Helaletes) ,|

LOPHIODONTID^E.

I X / II

TAPIRIDjE.

II Isectolophus annectens (S. and 0.)..........| X

EQUID^E.

Epihippus uintensis Marsh. 

Epihippus graciiis Marsh... 

Epihippus parvus Granger.

TlTANOTHERIlDJE (=BRONTOTHERIIDjE). a

Dolichorhinus cornutus (Osborn)

Telmatherium diploconum OsManteoceras SD. div. ............

X 

X

y

X

X 

X

y

i

Manteoceras SD. div. .........................

X 

X 

X 

X 

X 

X

ARTIODACTYLA.

Achcenodon insolens Cope.......

Achsenodon robustus Osborn....

Achaonodon uintensis (Osborn).. 

Achsenodon sp...................

Bunomeryx montanus Wortman. 

Bunomeryx elegans Wortman.. -.

"See footnote » on p..! l> Auct. Stehlin. See footnote t> on p. 98.
MAMMAL H6KIZOSTS

TIPPER EOCENE Continued:

ARTIODACTYLA Continued. 

CAMELIOE OR HYPERTRAGULID.E. 

1.. 2. 3. 4.

.Leptotragulus proavus S. and O. 

?Leptotragulus sp...............

Leptoreodon ?marshi Wortman.

X Leptotragulus proavus S. and O. 

Leptotragulus Itevi'is (Marsh).

Leptotragulus sulcatus (Marsh). 

Protylopus petersoni Wortman. 

Camelomeryx longiceps Scott... 

Oromcryx plicatus Marsh.......

OREOUONTID^E.

Protoreodon parvus S. and 0.....

Protoreodon puinilus (Marsh)....

Protoreodon paradoxicus (Scott). 

Protoreodon minor Scott.........

Protagriochoerus annectens Scott. 

Hyomeryx breviceps Marsh.......

of Eocene genera.

[The figures show the hUfnber of known species in each gentis. Crosses indicate that the presence of 

 the genus is recorded but no species have been described.]

iltlLflfUBERCULATA.

Chii'.ox. ..........................

PRIMATES.

Hemiacodon. . ...................

Euryacodon .....................

?Microsyopidi». .....................

Cynodontomys ..................

CARNIVORA (CREODONTA).

Clsenodon .......................

Palseonictidae (= Ambloctonidae) ....

Gen. indesc ......................

Basal.

First 

phase.

3 

1 

1

second 

phase.

i 

2

1

1

3

Lower.

First 

phase.

3

?2

2

2 

X 

X 

1 

1

X

1

1 

1

3

Second 

phase.

X 

4

2 

1

1 

1

2 

1 

X

X

2

1 

1

X

Middle.

First , 

phase.

X

3

1

2

1

1

2

3 

1 

1

2 

3

2 

1 

2

.1

Second 

phase.

i 

1

2 

1

2

2 

4 

4

1 

1

1

2

Upper.

First 

phase.

1

?

X

1

Second 

phase.

2

?l 

1
OF WESTERN NORTH AMERICA.

Range of Eocene genera Continued.

CARNIVORA (CREODONTA) COIlt'd.

Hyfenodontidne (Proviverrlmc) ....

Ox vclTmidcG

Protochriacus=Loxolophus. .... 

Carcinodon............. '........-

1NSECTIVORA.

? Talpidso. . ..........................

Centetodon ......................

Didelphodus. .................;..

TILLODONTIA.

Esthonyx .....................

Trogosus ........................

Tillotherium. ....................

RODENTIA.

Tillomys.........................

Protoptychus. ..................

Basal.

First 

phase.

3

2 

3 

1 

1

1

2

Second 

phase.

2

] 

1

1

4 

2 

1

1

4 

1

- .

2

:ii

Lower.

First 

phase.

6

3

J

1

5

X

2 

1

4

3

1

Second 

phase.

1

1

1

1

4

1

2

4

1

Middle.

First 

phase.

4 

1

1

i:

2

2

] 

1 

1

1

1 

1

1

1

2 f

3 

3 

4

1

Seconc 

phase.

3

I

. 2

3

2 

2 

1

1 

2

3 

1 

J

2 

J

? 3

1 

X

1 

1 

1

Upper.

First 

phase.

X

2

1

Second 

phase.

?

2

1 

X

-1
102 CENOZOIC MAMMAL HORIZONS

Range of Eocene genera Continued.

T^ENIODONTA.

Calamodon (incl. Dryptodon) . . .

EDENTATA.

Metacheiromyidse :

AMBLYPODA.

Eobasileus. . ....................

CONDYLARTHKA.

Euprotogonia ( = Tetraclaenodon )

Ectocion ........................

PERISSODACTYLA.

Hyrachyus ......................

Colonoceras .....................

Triplopus.......................

Heptodon .......................

Helaletes e. ......................

Systemodon ......'........ ......

Eohippus d. .....................

Oromppus «. ....................

Epihippus. ......................

Lambdotherinm ................

Eotitanops ......................

Limnohyops. . ..................

Telmathenum ...................

Diplacodon ......................

Basal.

First 

phase.

1

2

1 

1 

2 

1

1

2

v '

Second 

phase.

3

1

1

2 

1

2

2

Lower.

First 

phase.

4 

1

8

10 

1

3

2

4

10

Second 

phase.

1

3

1

2 

1

2

2+

1 

1

Middle.

First 

phase.

?1 

3-

X

1+

2

0

3 

1

Second 

phase.

19

5+ 

?1 

2

1 

1

1

3

2 

' 3 

5 

1

Upper.

First 

phase.

. 4

1

1

X

X

1 

X 

2

Second 

phase.

l

2

1

2

1 

2

o Including Dinoceras and Tinoceras.

<> Including Hyracops.

c Including Dilophodon.

A Including Protorohippus.

e Including Orotherium, Helohippus, Oligotomus, and Helotherium.
OF WESTERN NORTH. AMERICA. 103

Range of Eocene genera Continued,

ARTIODACTYLA.

TIeloh vus

Leptotragulus........ ...........

Basal.

First 

phase.

Second 

phase.

Lower.

First 

phase.

2

4

'!

Second 

phase.

1

Middle.

First 

phase.

X 1

2 

?1

1

Second 

phase.

1

1 

2 

?1

?

Upper.

First 

phase.

3

X 

X

Second 

phase.

2

4 

1 

1

3 

1 

1 

1

LOWER OLIGOCENE.

CHADRON (WHITE RIVER GROUP).

Titanotherium zone.

1. Chadron, South Dakota and adjoining parts of Nebraska and Wyoming.

2. Horsetail Creek, northeastern Colorado.

3. Pipestone Creek, Thompson'Creek, and other localities in Montana.

4. Swift Current Creek, Canada.

MARS TJPIALIA.

DlDELPHYIDffi.

Peratherium titanelixMatthew.

CARNIVORA (CREODONTA).

HY/ENODONTID;E .

? Pseudopterodon m i n u t u s 

(Douglass)«..................

Hemipsaloclon grandis Cope....

Hysenodon sp..................

CARNIVORA (FISSIPEDIA).

CANIDJE.

Daphaenus dodgei Scott.......

Daphaenus sp..................

Cynodictispaterculus Matthew. 

Cynodictis sp...................

? Cynodon sp..................

MUSTELIDJE.

Bunffilurus infelix Matthew..... 

FELID.E.

Dinictis fortis Adams. 

Dinictis sp.............

2. 3. 4.

INSECTIVORA.

LEPTICTID.E.

Ictops acutidens Douglass. 

Ictops thomsoni Matthew......

Ictops montanus Douglass. 

Ictops intermedius Douglass... 

Ictops tennis Douglass.........

Ictops major 

? CHRYSOCHLORIIXE.

ApternodusmediasvusMatthew. 

Xenotherium unicum Douglass.

FAM. INDET.

Micropternodns borealis Matthew ..........................

RODENTIA.

Prosciurus yetustus Matthew.. 

Prosciurus jeffersoni Douglass. .

CASTORlDjE.

Cylindrodon fontis Douglass. . . . 

Eutypomys sp. t>... .............

1. 2. 3. 4

a The type of this species is at present indeterminate. The reference to Pseudopterodon Is based on 

the specimen figured by Matthew, 1903. 

(> Auct. L. M. Lambe in lit.
104 CENOZOIC MAMMAL HORIZONS

LOWER OLIGOCENE Continued.

1. 2. 3. 4.

RODENTIA Continued.

ISCHYROMYnXE.

Ischyromys veterior Matthew., 

Gymnoptychus (=Adjidaumo)

minutus (Douglass).........

Gymnoptychus ( Adjidaumo)

minimus Matthew...........

LEPORUXE.

Palseolagus temnodon Douglass. 

Palseolagus brachyodon Matthew ..........................

PERISSODACTYLA.

HYRACODONTIM:.

Hyracodon priscidens Lambe... 

Hyracodon sp..................

AMYNODONTID.S: . 

Metamynodon sp........

RHINOCEROTHXE.

Trigonias osborni...............

Trigonias sp....................

Leptaceratherium trigonodum. 

Caenopus (=Subhyracodoh) sp.

div............................

Csenopus cf. platycephalus O.

and W........................

Csenopus mitis Cope............

LOPHIODONTUX9S.

Colodon (=Mesotapirus) occidentalis Leidy................

EQUHXE.

Mesohippus proteulophus Osborn...........................

Mesohippus hypostylus.........

Mesohippus celer Marsh........

Mesohippus montanensis Osborn..........................

Mesohippus latidens Douglass..

Mesohippus precocidens Lambe.

Mesohippus propinquus Lambe.

Mesohippns stenolophus Lambe

Mesohippus planidens Lambe.. 

Me son i p p u s assiniboiensis

Lambe........................

Mesohippus ? brachystylus Osborn..........................

? CHAUCOTHERIHXE.

" Chalicotherium " 

Cope a..........

bilobatum

TITANOTHERIHX3E (=BRONTOTHERIIDjE).

Titanotherium prouti Leidy.... 

Titanotherium nelocerus (Cope) 

Titanotherium trigonoceras 

(Cope)

Titanotherium ingens (Marsh) . Megaceropscqloradensis (Leidy) 

Megacerops dispar (Marsh) ..... 

Megacerops angustigenis Cope. . Megacerops selwynianus (Cope) . Megacerops tichoceras (S. and

0.). ...........................

Megacerops robustus (Marsh) . . 

Megacerops brachycephalus Osborn .......................... X

PERISSODACTYLA 

Continued.

TITANOTHERI1D2E ( = BRONTOTHERIID.E) continued.

Megacerops bicornutus Osboni.

Megacerops marshl Osborn.....

Allops serotinus Marsh.........

Allops crassicornis Marsh......

Allops amplus (Marsh).........

Symborodon torvus Cope.......

Symborodon acer Cope.........

Symborodon montanus (Marsh)

Brontotherium gigas Marsh

Brontotherium curtum Marsh..

Brontotherium ramosum (Osborn) .........................

Brontotherium dolichoceras (S. 

andO.).......................

Brontotherium platyceras (S. 

andO.).......................

Brontotherium leidyi Osborn...

Brontotherium hypoceras 

(Cope)........................

Brontotherium bucco (Cope)...

Titanotheriidse indet...........

ARTIODACTYLA.

E LOTHERiiD.fi (= ENTELODONElotherium (=Entelodon) coarctatum Cope. ...............

Elotherium (=Entelodon) 

crassum Marsh. ...............

Elotherium (=Entelodon) sp. 

div............................

Perchoerus sp...................

LEPTOCHCERIDjE.

Stibarus montanus Matthew...

ANTHRACOTHERIID^E .

Hyopotamus (=Ancodon) 

americanus Leidy.............

? Anthracotherium sp..........

OREODONTID.E (=AGKIOCHO>

Bathygenys alpha Douglass .... 

Limnenetes platyceps Douglass. 

? Limnenetes anceps Douglass. . 

Oreodon (=Merycoidodon) hybridus Leidy ..................

Oreodon (= Merycoidodon) affinis Leidy ....................

Oreodon (= Merycoidodon) bullatus Leidy ...................

Agriochcerus maximus DougAgriochcerus minimus Douglass ...........................

Agriochcerus sp.................

H YPERTRAGULID^.

Trigenicus socialis Douglass....

? Trigenicus mammifer Cope....

Leptomeryx esulcatus Cope....

Leptomeryx sp. div............

Heteromeryx dispar Matthew..

? Heteromeryx transversus

(Cope)........................

CAMELID^E.

? Leptotragulus profectus Matthew ..........................

1. 2. 3.

a Generic reference Incorrect; family reference very questionable.
OF WESTERN" NORTH AMERICA.

MIDDLE OLIGOCENE.

E (LOWER PART) (WHITE RIVER GROUP).

Oreodon zone.

1. Lower Brule, South Dakota and adjoining parts of Nebraska and Wyoming.

2. Cedar Creek, northeastern Colorado.

3. Scattered exposures in southwestern Montana.

105

^MARSTJPIALIA.

DIDELPHYJDA:.

Peratherium pygmseum (Scott) ..... 

CABNIVORA (CREODONTA).

HY^ENODONTID.B.

Hysonodoil paucidens O. and W. ....

Hysenodon leptocephalus S. and 0..

Hysenodon montanus Douglass .....

CARNIVORA (FISSIPEDIA).

CANID^E.

Daphconus hartshornianus (Cope).. .

Daphcenus nebrascensis (l:Iatcher)o.

Cynodictis lippincottlanus (Cope). ..

MUSTELID^E. .

. FELID^E..

Hoplophoneus prim?evus (Leidy) . . . 

Hoplophoneus occidentalis (Leidy) . 

Hoplophoneus oreodontis Cope. 

Hoplophoneus sp. (-transitional to

1NSECTIVORA.

ERINACEID^-;.

LEPTICTID^:.

SORICID.E.

Protosorex crassus Scott ...........

1.

 >

v

V

V

V

X

V

X

X 

X 

X

v

V

2. 

v

X

y

v

V

Y

X

X

X

.

y

3.

V

,

IN8ECTIVORA Continued. 

TALPID/E.

BODENTIA.

SCIURIMI.

CASTOBID/E. 

Eutypomys thomsoni Matthew. ....

Gymnoptychus (= Adjidaumo) triloMURIM:.

LEPOHJD/E.

PERISSODACTYLA.

HYRACOnONTIDJE.

AMYNODONTID^E.

RHINOCEKOTJM:.

Caenopus (=Subhyracodon) occlCsonopus (=Subhyracodon) sinipliLeptaceratne.riuiTi trigonodum (0. 

and W )............'...............

Anchisodon quadripllcatus Cope. . . .

LOPHIODONTID^E.

O. and W........ '..................

Colodon (=Mesotapiras) cingulatus

Colodon (==Mesotapirus) longipes 

0. and W............. .............

1.

X

v

y

v

x

V

V

2.

v

X

X

o Mr. Hatcher regarded this and the following species as types of distinct genera. As all the distinctive characters are functions either of the size of the species or the wear of the teeth they can hardly bo 

regarded as of generic importance. D. nebrascensis is in fact very closely related to D. felinus and 

D. vetus, and D. inflatus to D. hartshornianus.
106 CENOZOIC MAMMAL HORIZONS

MIDDLE OLIGOCENE Continued.

1. 2. 3.

PERISSODACTYLA Con. 

TAPIR IDA:.

Protapirus simplex Wortman and 

Eane.............................

EQUID.&:.

Mesohippus bairdii Leidy............

Mesohippus obliquidens" Osborn....

Mesohippus eulophus Osborn........

Mesohippus exoletus (Cope).........

ARTIODACTYLA.

ELOTHERIIDJE (=ENTELODONElotherium (=Entelodon) mortoni 

(Leidy)...........................

Elotherium (=Entelodon) ingens 

Leidy.............................

Elotherium (=Entelodon) crassus 

Marsh ............................

Pelonax ramosus Cope a. ...........

(=TAGASSUIDA:)-

Perchcerus probun Leidy............

Perchoerus nanus (Marsh)...........

ANTHRACOTIIERITPA:.

Anthracotherium curtum (Marsh)..

Hyopotamus (=Ancodon) rostratus (Scott)........................

Leptochcerus spectabilis Leidy......

Leptochcerus lemurinus (Cope).....

ARTIODACTYLA Con.

LEPTOCHCERIDA: continued.

Leptoehcerus robustus (Marsh).....

Leptochcerus gracilis Marsh.........

Stibarus obtusilobus Cope..........

Stibarus quadricuspis (Hatcher)....

OREODONTIDA: (=AGRIOCHCERTDJE).

Agriochcerus antiquus Leidy.......

Agriocho?ms latif rqns Leidy.......

Oreodon (=Merycoidodon) culbertsoni (Leidy)......................

Oreodon (=Merycoidodon) gracilis

Leidy.............................

Oreodon (=Merycoidodon) coloradensis Cope.......................

Oreodon (=Merycoidodon) periculorum Cope.......................

Oreodon (=Merycoidodon) macrorhinus Douglass..................

Oreodon (=Merycoidodon) sp. cf.

bullatus Leidy....................

Leptauchenia sp....................

H YPERTRAGULIDA:.

Hypertragulus calcaratus Cope.....

Hypertragulus sp. div............

Leptomeryx e'vansi Leidy........

Leptomeryx sp. div..............

Hypisodus minimus Cope........

CAMELIDJE.

Poebrotherium wilsoni Leidy..... 

Poebrotherium labiatum Co'oe. 

Poebrotherium eximium Hay.... 

Paratylopus primajvus Matthew....

1. 2. 3.

UPPER OLIGOCENE.

FIRST PHASE BRULE, UPPER 

(WHITE KIVER GROUP).

PART

Protoceras and lower Leptauchenia zones.

1. "Upper Brule, South Dakota and adjoining 

parts of Nebraska and Wyoming.

2. Lower Martin Canyon, Colorado.

3. White Buttes, North Dakota.d

4. Blacktail Deer Creek, Montana (?).«

CARNITORA (FISSIPEDIA).

CAN: DA:.

SECOND PHASE JOHN DAY.

Diceratherium and Promerycochoerus zones.

1. John Day, Oregon.c

2. ? Druinmond, Montana.

Paradaphsenus cuspigerus (Cope)................................

Paradaphsenus transversus W. and M...........................

Nothocyon geismarianus (Cope).................................

Nothocyon lemur (Cope).........................................

Nothocyon latidens (Cope)......................................

Cynodictis temnodon W. & M....................................

Cynodictis oregonensis Merriam.................................

Mesocyon coryphajus (Cope).....................................

Mesocyon josephi (Cope)............................'.............

a ? Upper Oligocene.

b This group may perhaps belong in Dichobunidaj.

c Chiefly auct. J. C. Merriam and W. J. Sinclair. The level of many species (marked " ? ") Is doubtful 

as it is.determined only by character of matrix. Where the level is unknown, it is given as between b 

and c, the lower beds of the formation being.practically barren.

d Additional species from this region have been described by Douglass since the date of preparation 

of these lists. See Ann. Carnegie Mus., vol. 4, No. 2, 1907. The Oreodon horizon is also included in 

these exposures.

«More probably Lower Miocene.
OP WESTERN NORTH AMERICA. 

UPPER OLIGOCENE Continued.

107

CARNTVORA (FISSIPEDIA)-Continued. 

CANID^E Continued.

Mesocyon brachyops Merriam . . . ..................................

Temnocyon altigenis Cope ..... ............ . .................

Temnocyon wallo vianus Cope ......................................

Temnocyon ferox Eyermann ........................................

Philotrox condonl Merriam ..................................'......

Enhydrocyon stenocephalus Cope. .................................

Enhydrocyon basilatus Cope. ......................................

Enhydrocyon sectorius (Cope) .....................................

MUSTELIDtf:.

Parictis primsevus Scott ..................... .....................

FELID<E; 

Dlnictls bombif rons Adams ........................................ Dinictis cyclops Cope. .............................................

Nimravus debilis (Cope) ..................... ...

INSECTIVORA.

TALPID^D.

RODENTIA.

SCIURIWE.

CASTORID^E. 

Steneoflber nebrascensis (Leidy) ....................................

Steneoflber peninsulatus Cope ......................................

GEOMYJOE.

APLODONTIID^J.

MURID/E.

Peromvscus narvus Sinclair. .........................................

1.

X

X 

X

X

2.

X

3. 4.

X

a.

1.

 .* -

b.

X

X 

X

X

X 

X

X

X 

X

X 

X

X 

X 

X 

X

X 

X 

X

X 

X 

X 

X 

X

X 

X 

X

Y

c.

X 

X

X

?

1 

X

X

7 

X 

X

X

a See Matthew, Bull. Am. Mus. Nat. Hist., 1907, p. 193, for position of this genus. 

i> Madison Valley, Montana, tProtoceras zone, 

c Related to Dipodidte auct. Scott.
108 CENOZOIC MAMMAL HOKIZOKS 

UPPER OLIGOCENE Continued.

RODENTIA Continued 

LEPOBID/S.

Palseolagus agapetillus Cope......

Palseolagns intermedius Matthew. 

Lepus ennisianus Cope............

PERIS SODACTYLiA.

H VBACODONTI D^E.

Hyracodon sp. div.

RniNOCEBOTIlXE.

Caenopus tridactylus Osborn......

Caenopus platycephalus 0. and W. 

? Caenopus pacificus Leidy 11.......

? Caenopus truqnianus Cope.......

? Csenopus tubifer Cope...........

? Caenopus annectens Marsh......

Diceratherium armatum Marsh... 

Diceratherium nanum Marsh.....

2.

TAPIRIMS.

Protapirus robustus Sinclair......

Protapirus obliquidens W. and E. 

Protapirus validus Hatcher.......

Mesohippus intermedius 0. and W. 

Mesohippus meteulophus Osborn.. 

Mesohippus brachystylus Osborn.. 

Mesohippus acutidens Sinclair.....

Mesohippus equiceps (Cope)........

Mesohippus brachylophus (Cope).. 

Mesohippus longicristis (Cope).....

Miohippus anceps Marsh...........

Miohippus annectens Marsh........

Miohippus condoni (Leidy)........

Miohippus validus Osborn.........

Miohippus gidleyi Osborn..........

Miohippus crassicuspis Osborn....

Anchitherium praestans Cope.......

CHALICOTHERIIDJE.

Moropus ("Lophiodon") oregonensis Leidy. 

Moropus senex Marsh........................

Moropus distans Marsh......................

ARTIODACTYLA.

ELOTHERHM; (=ENTELODONTID^).

Daepcloni) shoshonensis Cope..................

Boocho3rus humerosus Cope .................

? Elotherlum (=Entelodon) imperator Leidy. 

? Elotherium (=Entelodon) calkinsiSinclair. 

Elotherlum (=Entelodon) cf. ingens Leidy....

Elotherium (=Entelodon) ?crassusMarsh....

Elotherium (=Entelodon) bathrodon Marsh.. 

Elotherium (= Entelodon) sp..................

3. 4.

X 

X 

X I ?

X

a This and the three following species may be referable to Diceratherium.

l> Dxodon Cope, 1878, Botichcerus Cope, 1879, and Dmohyus Peterson, 1900, quite probably refer to 

one and the same genus, distinguished from Elotherium. by slight development of chin bosses, 

moderate expansion of dependent processes of jugals, and certain minor changes in the premolars. 

E. calkinsi Sinclair belongs to this group, and perhaps other John Day species,
OF - WESTEBN JSTOHTH AMEfttCA, 

UPPER OLIGOCENE Continued.

109

AKTtOOACfYtiA-Continued. 

(=TAGASSUUJ,*:).

2. 3. 4

Perchceru's f obustus (Marsh) .-.... . ; .,,,,,.,........................ X

Perchoorus pristinus (Leidy) ; ^ 

Perchcerus socialis (Marsh)....

Perchoarus lentus (Mar'sli) ....

Perchoerus subtcquans (Cope). 

Perchccrus rostratus (Cope) .. 

Perchcorus trichaenus (Cope). ^ 

? Perchoerus platyops (Cope)........ ; . .-.. ... .-. ..-.,.,................. X

Perchoerus dsmonti (Sinclair).......................................

Chanohyus decedens Cope.........................,,,,,.,.,...........!

LEPTOCHCERID^K. 

Leptochoerus sp..................................................... X

ANTHRACOTHERIID/15.

Anthracotherioin karense 0. and W................................ x

Byopotamus (=Ancodon) hrachyrhynchus 0. and W.............. X

Arretotherium acridens Douglass.....................

OREODONT

Agriochocrus major Leidy........................................... X

Agriochoerus gaudryi (O. and W.)

Agriochcerus migrans (Marsh)...................................... x

Agriochcerus ferox (Cope)............................

Agriochcerus guyotianus (Cope)......................

Agriochcerus ryderanus (Cope).......................

Agriochoirus macrocephalus (Cope)..................

Agriochcerus trifrons (Cope)..........................

Eporeodon (?=Eucrotaphus) occiclentalis (Marsh)... 

Eporeodon leptacanthus (Cope)... 

Eporeodon (?=>Eucrotaphus) paciflcus (Cope)........

Eporeodon (?= Eucrotaphus) trigonocephalus (Cope) 

Eporeodon (?=Eucrotaphus) longifrons (Cope)......

Eporeodon major (Leidy).......................| X X

Eporeodon (?= Eucrotaphus) cedrensis Matthew................... x

Eporeodon (?= Eucrotaphus) socialis Marsh.....

Eucrotaphus jacksonl Leidy .....................

.fromerycochcorus superbus (Leidy)..............

Promerycochcerus macrostegus (Cope)...........

Prornerycochcerus chelydra (Cope)................

Promerycochcerus leidyi (Bettany)..............

minor Douglass...............

Leptauchenia sp.................................................... x

H Y PERTE AGULl KJE.

Hypertragulus hesperius Hay..............

Hypertragulus planiceps (Sinclair).........

Leptomeryx sp. div.................................................. x

Leptomeryx transmontanus Douglass.

Protoceras celer Marsh.............................................. x

Protoceras comptus Marsh......................................... X

Protoceras nasutus Marsh............................. 1............ x

Galopscristatus Marsh.............................................. x

Galops censors Marsh................................................ x

CAMEUIXE.

Paratylopus sternbergi (Cope)..........

Paratylopus cameloides (Wortman)....

Pseudolabis dakotensis Matthew.................................... X

Camelidfe indet.....

X 

X 

X
110 CENOZOIC MAMMAL HOEIZONS

Range of Oligocene genera.

MARSUPIAL1A.

CARNIVORA (CREODONTA).

CARNIVORA (FISSIPEDIA).

Dinictis ...........................................................

INSECTIVORA.

Xenotherium ................................................

Fam. indet.:

RODENTIA.

Cylindrodon. . ................................................... .

Eutypomys ..............................................:........

Steneofiber. .......................................................

Ischyromyidse. ........................................................

Geomyidee. ............................................................

Entoptychus. .....................................................

Pleurohcus. .......................................................

Aplodontiidse. ........................................................

Meniscomys. ......................................................

Eumys ...........................................................

Lepus .............................................................

Lower.

1

1 

1 

X

X 

1 

1

1

1

6

2 

1

1

2

1

1

2

2

Middle.

7

7

5

2

1

?

3

3

2 

1 

1

1

1

3

1

1

. 2 

2

1

2

Upper.

White 

River.

1

1

1

1

3

2

John 

Day.

1 

2 

3 

4 

3 

1 

3

1

1 

3 

3

2

2

7 

3

" 5 

1

.2 

2

1
OF WESTERN NORTH AMERICA. Ill

Range of Oligocene genera Continued.

I'ERISSOIMCTYLA. .

Moropus ..........................................................

ARTIODACTVLA.

Lower.

1

X

1

1

2

1

11

?

4 

12 

3 

8

1

X

1

X

1

1

3

2

2

2 

1 

2

1

Middle.

4

1

1 

3

5

1

4

4

2

2 

4

1

1

6

1

2

1

1 

1

1 

3

Upper.

White 

River.

X

2

2

3 

3

3

3

1

1 

1 

1

1

1 

3

3

2

1

John 

Day.

4 

2

1

4 

3 

1

3

5

8 

1

C

l>

5

.1 

2

2

» Including ^1 Hops.

b Including Pelonax, Dxodon, and Soochcerus.
112 CENOZOIC MAMMAL HORIZONS

LOWER MIOCENE.

ARIKAREE FORMATION (IN PART).

Prornerycochcerus zone. 

FIRST PHASE HARRISON. SECOND PHASE.

1. Fort Logan, Montana.

2. Harrison, Nebraska.

3. Monroe Creek, Nebraska.

4. Lower Rosebud, South Dakota.

5. Canyon Ferry, Montana.

1. Larainic Peak, Wyoming.

2. Upper Harrison, Nebraska.

3. Upper Rosebud, South Dakota.

4. Uppermost Martin Canyon, Colorado

CABNIVORA.

Nothocy on gregorii Matthew 

Nothocyon vulpinus MatNothocyon annectens PeterNothocyon ? lemur Cope .... 

Cynodesmus thooides Scott.. 

"Amphicyon" superbus PeMesocyon robustus Matthew

Enhydrocyon eras sidens 

Matthew ..................

1.

X

2.

V

3. 

X

X

X

4. 

X

V

V

X

X 

Y

5.

Cynodesmus brachypus (Cope) . 

Cynodesmus thomsoni MatCynodesmus minor Matthew . . .

1. 

X

I

2. 3. 

v

X

? Brachypsalis simplicidens 

Peterson.................

PEOCYONID^E.

|| Phlaocyon ieucosteus Matthew. 

MUSTELID/E.

Oligobunis lepidus Matthew....

Megalictfs ferox Matthew..... ...

JSlurocyon brevifacies Peterso

Nimrayus sectator Matthew | r i x i i!

INSECTIVORA.

Euhapsis brachyceps Peterson ........................

Euhapsis gaulodon Matthew

Steneofiber ?pansus Cope...

Steneofiber fossor Peterson..

Steneofiber barbouri Peterson .........................

Steneofiber simplicidensMatthew...............'.......

Steneofiber sciuroides Matthew ......................

Steneofiber brachyceps Matthew

Steneofiber montanus Scott.

Meniscomys sp. -I I X I

Entoptyehus formosus Matthew ......................

Entoptyehus curtus Matthew ......................

|| Arctoryctes terrenus Matthew. 

RODENTIA.

CASTORID^E.

X 

X 

X

APLODONTIIOE. 

I X'l i 

GEOMYIM:.

Entoptyehus formosus Matthew 

X Entoptyehus curtus Matthew ..

X 

HETEROMYID^E. 

il HetcroJiiyidto itidet............. I X i
OF WESTERN NORTH AMERICA. 113

Lepus primlgenius Matthew. 

Lepus macrocephalus Matthew......................

LOWER MIOCENE Continued. 

RODENTIA Continued.

LKPORIDJE. 

1. 2. 3. 4. 5.

Lepus macrocephalus Matthew.

1. 2. 3. 4.

Diceratherium cooki Peterson ........................

Diceratherium niobrarense 

Peterson..................

Diceratherium sp...........

PERIS SOD ACT YLA.

RHINOCEROTID.E.

? Diceratherium sp.

Moropus ? elatus Marsh....:] | X I

X

CH ALICOTHERIID.iE.

I | || Moropus ? elatus Marsh. 

EQUID^E.

-I I X

Parahippus aff. crenidens

"Miohippus annectens 

MarsrA.. ................

'Miohippus equiceps Cope".

v

X

V

y

Parahippus nebrascensis Peter-

.

ARTIODACTYTjA.

ELOTHERIIDJE (=ENTELODONTID.S:) .

Dinohyus hollandi Peterson. 

Blotherium sp...............

Desmathyus siouxensis (Petrrson).................... X

(=TAGASSUiaE).

ii Desmathyus pinensis Matthew . 

II Desmathyus sp.................

OREODONTID^E (=AGRIOCH(ERID.<E) .

Mesoreodon chelonyx Scott . 

Mesoreodon inte r m e d i u s

Mesoreodon megalodon PeMesoreodon ? latidens DougEporeodon sp. div ..........

Promerycochoerus carriken

Promerycochojrus vantasPromerycochcerus sp. div . . . 

Promerycochoerus natcheri

Promerycochoerus gra.ndis

Promerycochoerus hollandi

Merycoides cursor Douglass. 

Phenacocoelus typus Peter-

' ' Merychyus elegans Leidy " c 

"Merychyus" harrisonensis

Leptauchenia decora Leidy.. 

Leptauchenia major Leidy. . 

Leptauchenia nitida Leidy..

X

v

X

X

v

X

X

?

X 

X 

X

V

X

v

X

Merycochcerus proprius Leidy «. 

Merycochcerus rusticus Leidy * .

Merychyus arenarum Cope .....

Merychyus minimus Peterson . .

X

X 

X

X

X

X

a "Headwaters pi Niobrara River, near Fort Laramie.",

(> Sweetwater River, Wyoming.

c Specific reference probably erroneous; generic reference of this and the following species doubtful. 

The typicnl Merychyus is from the upper Miocene; the skull structure in the middle Miocene species is 

considerably more specialized than in any from the lower Miocene and although unknown in the upper 

Miocene species is presumably still more specialized. The species from this early phase of the lower 

Miocene have in general more brachydont molars, and it may prove necessary to separate them generically.

56092 Bull. 361 09 8
114 CENOZOIC MAMMAL HOEIZONS

'' Poebrotherium sp.".......

Stenomylus gracifis Peterson ........................

LOWER MIOCENE Continued. 

AKTIODACTYLA Continued.

CAMELID.S;. 

l. 2. 3. 4. 5.

X Protomeryx halli Leidy.........

Protomeryx ? cedrensis Matthew..........................

Protomeryx sp. div.............

Oxydactylus longipes Petersou. 

Oxydactylus brachyceps Peterson.

1. I 2. 3. 4

Syndyoceras cooki Barbour.

Hypertragulus ordi n a t u s

Matthew..................

Hypertragulus Cope'" "calcaratus 

HYPERTRAGULID^E.

X X 

ANTILOCAPRID.S: (MERYCODONTIN.*:) .

Blastomeryx ad vena Matthew. 

Blastomeryx sp...............

MIDDLE MIOCENE.

DEEP RIVER SEQUENCE.

Ticholeptus zone.

1. Deep River (Smith River), Montana.

2. Pawnee Creek, northeastern Colorado.

3. Flint Creek, Montana; ? North Boulder Creek, Montana, etc.

4. Mascall, Oregon.

CARNIVORA.

CANID^E.

Tephrocyon rures^ris Merriam. 

Cynarctus saxatilis Matthew. . . 

Amphicyon sinapius Matthew. .

'Canis" cf. temerarius Leidy.. .

Tomarctus brevirostris Cope . . .

??Aelurodon brachygnathus

MUSTELID.&.

Potamotherium lycopotamiFELID.E.

INSECTIVORA.

Talpa platybrachys Douglass . . 

RODENTIA.

Sciurus sp.. .....................

1. 

v

2.

X 

X

X

X

X 

X

v

X

3.

X

X

4. 

X

X

ROD ENTIA Continued. 

MYLAGAULIM;.

Mylagaulus Isevis Matthew ..... 

Mylagaulus paniensis Matthew . Mesogaulus ballensis Riggs .....

?MEGALONYCHIDx£.

PROBOSCIDEA.

Trilophodon (=GomphotheriTrilophodon (=GomphotheriPERISSODACTYLA.

RHINOCEROTHXE.

Csenopus persistens Osborn... 

Aphelops megalodus Cope. . . . . 

Aphelops profectus (Matthew) . 

Aphelops planiceps Osborn .... 

V Aphelops oregonensis (Marsh)

Teleoceras inedicornutus Osborn .........................

1.

X

2.

X 

X

X

X

X 

X 

X 

X

X

a Blue Creek, Nebraska, associated with Cyclopidius,
OF WESTERN NORTH AMERICA. 115

MIDDLE MIOCENE Continued.

1. 2. 3. 4.

PERISSODACTYLA COM.

Tapiravus sp..................

EQUII.X*:.

Merychippus sejunctus (Cope). 

Merychippus labrosus (Cope).. 

Merychippus isonesus (Cope).. 

Merychippus paniensis (Cope). 

Merychippus sphenoclus (Cope) 

Merychippus seversus (Cope) - - Merychippus campestris Gidley 

Hypohippus equinus Scott....

Hypohippus osbomi Gidley... 

Hypohippus sp................

Parahippuscreriidens (Scott).. 

Parahippus brevidens (Marsh). 

Parahippus avus (Marsh).....

Parahippus pawniensis Gidley. 

Parahtppuscoloradensis Gidley 

Archffiohippus ultimus (Cope). 

Archseohippiis sp. div..........

Moropus sp.....................

ARTIOD ACTYLA.

DICOTYLIM: (=TAOASSUIDA:). 

Hesperhys vagrans Douglass...

OREODONTItX'E ( = AGRIOCHCERID^E).

Pronornotherium laticeps 

(Douglass)....................

Merycochceruscf.proprius Leidy 

Merycochoeruscf. rusticus Leidy 

Promerycochcerus rriontanus 

(Cope)........................

?Promerycochcerus obliquidens 

(Cope).........................

ABTIODACTYLA-Con.

OREODONTIDjE ( = AGRIOCHO;-

 Continued.

Tlcholeptus zygomaticus Cope.. 

Ticholeptus brachymelis Douglass...........................

Ticholeptus breviceps Douglass. 

Ticholeptus bannackensis Douglass ...........................

Poatrephes paludicola Douglass. 

Mesoreodon longiceps Douglass. 

Merychyus pariogonus Cope ....

Merychyus smith! Douglass. . . .

Merychyus sp. div ..............

Cyclopidius (= Pithecistes) decedens (Cope) .................

Cyclopidius (= Pithecistes)

emydinus Cope. ...............

Cyclopidius (= Pithecistes)

slmus Cope.. . .................

Cyclopidius (= Pithecistes) incisivus Scott. .................

CAMELIWE.

Miolabis transmontanus (Cope) 

Protolabis longiceps sp. nov.« 

Protolabis heterodontus Cope. 

Protolabis angustidens (Cope). 

Procamelus flssidens Cope. . . . . 

Alticamelus altus (Marsh) ..... 

Alttcamelus leptocolon sp. nov.fr

Palseomeryx borealis Cope. .....

Palseomeryx antilopinus Scott . 

Palseomeryx sp .................

Blastomeryx gemmifer Cope. . . .

ANTILOCAPRID.S: (MERYCODONTIN^:) .

Merycodus osborni Matthew....

1. 2. 3. 4.

X

UPPER MIOCENE AND ?LOWER PLIOCENE.

FORMATION SECOND PHASE 0&ALALLA FORMATION.

Peraceras zone (doubtfully separable).

FIRST PHASE ARIKAREE 

(IN PART).

Procamelus zone.

1. Fort Niobrara (''Nebraska formation"), Nebraska.

2. Little White River, South Dakota.

3. Santa Fe, New Mexico.

4. Clarendon, Texas.

5. Madison Valley, Montana.

1. Republican River, Kansas and Nebraska.

2. Archer, Florida (Alachuaclays).

3. Rattlesnake, Oregon.

CARNIVORA.

CANID^E.

? Dinocyon ursinus (Cope) ..........................................

1 schvrocvon hvsenodus Matthew. ..................................

1.

X 

X

X 

X

?

X 

X

2.

X 

X

? 

V

a "P. montanus Douglass," Matthew, Mem. Am. Mus. Nat. Hist., vol.1, pt. 7, 1901, p. 435, figs. 31-33. 

Not P. montanus of Douglass.

b "Procamelus robustus Leidy," Matthew, op. cit., p. 427, fig. 30. Not P. robustus of Leidy. 

c Including JE. taxoides Hatcher.
116 CENOZOIC MAMMAL HORIZONS

UPPER MIOCENE AND ? LOWER PLIOCENE Continued.

C AKNIVOKA Con ti n uecl.

? PR.OCYONID.iE.

Leptarctns primus Leidy.........................

MUSTELIIWE.

Mustela minor Douglass..........................

Putorius nambianus (Cope)......................

Potamotherium robustum (Cope)................

Potamotherium lacota Matthew..................

Lutra pristina Matthew..........................

Brachypsalis pachycephalus Cope.................

"Machserodus" catpcopis Cope..........

? Machserodus maximus Scott & Osborn. 

? Machaerodus augustus Leidy...........

? Machserodus crassidens Cragin.........

Pseudselurus intrepidus Leidy...........

RODENTIA.

Sciurus arctomj'oides Douglass.......

Paltearctomys montanus Douglass... 

Paleearctomys macrorhinus Douglass. 

Palsearctomys vetus (Marsh).........

Cynomys sp...........................

CASTOKIM:.

Eucastor (=Dipoides) tortus Leidy. 

Sigmogomphius lecontei Merriam...

MYLAGAULID2E.

Mylagaulus sesquipedalis Cope.. 

Mylagaulus monodon Cope......

Mylagaulus pristinus Douglass.. 

Mylagaulus proximus Douglass. 

Mylagaulus paniensis Matthew. 

Epigaulus hatcheri Gidley......

GEOMYIIXE.

Geomys bisulcatus Marsh .....................

MURIOE. 

Hesperomys (= Peromysctis) loxodon (Cope) .

Panolax sanctajfldei Cope. 

'Lepus sp. ................

PROBOSCIDBA.

ELEPHANTID^;.

Trilophodon (=Goinphotherium) productusCope.. 

Trilophodon (=Gomphotherium) euhypodon Cope. 

Trilophodon campester Cope.. 

Trilophodon praecursor Cope.. 

Trilophodon (= Gomphotherium) floridanus Leidy.

PEBISSODACTYLA.

RHINOCEROTID^:.

Teleoceras fossiger Cope...........

Teleoceras crassus (Leidy)........

Teleoceras sp. diy.................

Peraceras superciliosus Cope......

? Aphelops malacorhinus Cope....

? Aphelops ceratorhinus Douglass. 

? Aphelops jemezanus Cope.......

? Aphelops brachyodus Osborn....

2.

Bijou Hills.

X

X

TAPIRIOE. 

Tapiravus rarus Marsh «.........................................

a Recorded as corning from the " lower Pliocene, east of the Rocky Mountains."

Gal iornia
OF WESTERN NORTH AMERICA. 117

UPPER MIOCENE AND ? LOWER PLIOCENE Continued.

PERI.SSODACTYL.A Continued.

EQUIDjE.

Protohippus interpolates Cope. ....................................

Neohipparion whitneyi Gidley . . ....................................

Neohipparion niobrarense Gidley ...................................

ARTIODACTYLA.

DlCOTYLID.iE (=TAOASSUID2E).

OKEODONTID./E (=AGBIOCHOSRID^:).

CAMELID.E.

Pllauchenla sp. ......................................................

PJiauchenia so. max. .......'...................................... .

1.

X

X 

X

X 

X 

X 

X 

X 

X 

X

v

w

X

?

V

X 

X 

X

X 

X 

X

2.

X 

X

X 

X 

X 

X

n

X

XX' 

Bijc

* 

J

X

AX

X

X 

X

X

3. 

X

exic

u 1-1 

 X

^exir 

:exic

exic

X 

X

4. 

X

0.

X 

X

11s.

0. 

0.

X

X

o.

X 

X

X

5.

X

X 

X

X 

X

1. 

X

0 

D

X

O 

D

X

Pe

X

X 

X

X

X

X 

X

X

2.

rego 

eser

rego 

eser

ice, C 

Fla.

"X 

X

X 

X 

X

3.

n 

t. 

X

n 

t.

? 

,r.,

a"Pliauchenia humphreysiana Cope," VVortman, 1899, not of Cope. Jaw larger, more robust, 

premolars more reduced, p. 2 absent, while in P. humphrcsiana it is vestigial.
CENOZOIC MAMMAL HOEIZONS

UPPER, MIOCENE AND FLOWER PLIOCENE Continued.

1. 2. 3. 4. 5. 1. 2. 3.

ARTIODACTYLA Continued. 

CERVIM:.

Palseomeryx americanus Douglass. 

Palseomeryx teres (Cope)..........

Palseomeryx trilaterahs (Cope)....

Palseomeryx sp. diy................

Blastomervx wellsi Matthew.......

ANTlLOCAPRIDJE (MERYCODONTIN^E).

Merycodus necatus Leidy......

Merycodus furcatus (Leidy)....

Mervcodus rarnosns (Cope^....

Merycodus agilis Douglass.....

? ?Merycodus tehuaniis (Cope).

Range of Miocene genera.

[The figures show the number of described species in each genus. Crosses indicate that the presence of 

the genus is recorded, but no species have been described.]

CARNIVORA.

Phlaocyon ................................................

Oligobunis. ................................................

Aelurocyon ...............................................

Megalictis. ................................................

Potamotheriurn ....................... ..................

T7oliH»

Pseudselurus. . ............................................

' ' Machaerodu s "...........................................

INSECTIVORA.

RODENTIA.

Eucastor (=Dipoides) ....................................

Lower.

Lower Rosebud.

4 

1 

2

? 1

1

?

1

2 

7

Upper Rosebud.

3

1

1 

1 

1

1

Middle.

? 

1 

1

1

? 

1 

?

?

2

1

1

X

Upper.

"Nebraska."

2

?1 

3 

1

5

1

2 

1 

1 

1 

1

1 

3

1 

3

]

" Republican River."

X

1

2

1

? 

I
OP WESTERN NORTH AMEEICA. 119

Range of Miocene genera Continued.

RODENTIA continued.

Ceratogaulus. . ...........................................

Hcteromyid indet ........................................

EDENTATA.

Megalonychidao: *

PROBOSCJDEA.

PEKISSODACTYLA.

ART1OOACTVLA.

Cvclonidius. ..............................................

Lower.

Lower Rosbud.

2

X

1

2

X

3

1

? 

1

1

X. 

4 

1 

1 

3

5

3

Upper Rosebud.

2

X

1

?

?

3

X

1

3

2

Middle

2 

1 

1

X

?

2

1

4 

1

X

1 

2 

5

7

X

1

1

2 

5 

2 

2 

1

4

Upper.

"Nebraska."

4

1

1

X

1

2

3 

2

X

1 

1

2 

12 

12

1

3

1 

? 

1

Republican " River."

2 

1

X

3

1 

1 

1

X

3 

C

:. 1

X

?
120 OENOZOIC MAMMAL HORIZONS OF WESTERN NORTH AMERICA.

Range of Miocene genera Continued.

ARTIODACTYLA continued.

Pliauchenia. ..............................................

CervidcG

Merycodus. ...............................................

Lower.

Lower Rosebud.

1

1 

2

Upper Rosebud.

2 

2

1

Middle.

1 

3 

2 

?

2 

1

1

Upper.

"Nebraska."

2 

? 

6 

1

3 

1

6

Republican ' 'River." 

1 

4 

3

X

MIDDLE PLIOCENE.

BLANCO FORMATION (TEXAS). 

Glyptotherium zone.

CARNIVOKA.

CANID-E.

Borophagus diversidens Cope. 

? Amphicyon sp.

MUSTELID^E. 

Canimartes cummins! Cope.

FELUWE. 

Felia hillanus Cope.

EDENTATA.

GLYPTODONTIDJE. 

Glyptotherium texanum Osborn.

MEGALONYCHHXE. 

Megalonyx leptostoma Cope.

MYLODONTID^E. <f

Mylodon sp.

PROBOSCIDEA.

ELEl'HANTIDjE.

Trilophodon (=G omphotherium) shepardii Leidy.a

Dibelodon miriflcus Leidy.

Dibelodon tropicus Cope.

Dibelodon praecursor Cope.

? Dibejodon hiimboldtii (Cuvier).

PERISSOBACTYLA.

Pliohippus simplicidens (Cope).

Protohippus ininutus (Cot)e) (=phlegou (Hay)).

Protohippus cumminsii (Cope).

Neohipparion sp.

ARTIODACTYLA.

DICOTYLID.S; (=TAGASSUID^E).

Platygonus bicalcaratus Cope. 

Platygonus texanus Gidley.

CAMELID^E.

Pliauchenia spatula Cope. 

Pliauchenia sp.

« This species should probably be referred to Dibelodon.
INDEX.

A. Page. 

Acer........................................ 78

Aceratheriince......................... 01,64,67,08

Achfenodon................................ 54,103

insolens................................. 99

robustus................................ 99

uintensis................................ 99

sp....................................... 99

Achsenodontidse......................... 95,99,103

Ach£enodontina3............................. 57,01

Adjldaumo minimus....................... 104

minutus............................... 104,105

trilophus................................ 105

-ffilurocyon................................. 74,118

brevifacies.............................. 112

^Elurodon............................... 80,81,118

brachygnathus.......................... 114

compressus.............................. 115

haydenl................................. 115

hyaenoidcs.............................. 115

stevus.!................................. 115

taxoidcs................................. 115

wheelerianus............................ 115

Agriochceridse.................. C3,113,115,117,118

Agrlochdprinffi................................ 69

Agriochcorus............ j.................. (18, 111

untiquus................................ 106

ferox..................................... 109

gaudryl................................. 109

guyotanus .............................. 109

latifrons.....:........................... lOii

macroccplialus.......................... 109

major................................... 109

maximus................................ 104

migraus................................. 109

minimus................................ 104

ryderanus............................... 109

trifrons.................................. 109

sp. ....................................... 104

Alces..................................... 86,87,89

Allomys..................................... 66

cavatus..........:...................... 107

hippodus ........................... .. 107

liolophus................................ 107

multiplicatus............................ 107

nitens .................................. 107

Allops ampins .............................. 104

crassicornis.............................. 104

serotinus................................. 104

Almy formation, section of,.figure showing... 39 

Alticamelus............................. 78,81,120

altus................................... 81,115

leptocolon.......................'....... 115

Ambloctonidffi............................. 93,100

Page. 

Ambloctonus................................ 100

sinosus.................................. 93

Amblypoda................................. 33,

35, 37, 40, 41, 42, 45, 49? 52, 54, 50, 57, 92, 

94, 97, 99, 102. 

American correlation, problem of............ 29

American-Eurasiatic correlation, problem of. 29-30 

American-European faunas, correlation of.... 59

Americoids.................................. 40

Arnphicyon................. 69,72,74,77,78,83,118

sinapius................................. 114

supcrbus................................ 112

sp....................................... 120

Amphicyoninee .............................. 77

Amynodon................................... 102

advcnus................................. 99

antiquus................................ 99

intermedius...................:......... 99

sp........................................ 99

Amynodontidse............................. 54,

57,60,61,62,63,99,102,104,105,111 

Anacodon............................... 38,45,100

ursidcns................................. 93

Anaptomorphidffi................. 40,52,93,95,100

Anaptomorphus............................. 100

abboti................................... 93

semulus................................. 95

homunculus............................. 93

minimus............................'.... 93

spierianus............................... 93

sp....................................... 95

Anchippodontidffi....................... 94,97,101

Anchippodus................................ 52

vetulus.................................. 97

Anchisodon quadriplicatus.................. 105

Anchitherium.......................... 75, 111, 119

praestans............................... 68,108

sp....................................... 113

Ancodon. See Ilyopotamus.

Anguidse.................................... 47

Anisacodon .................................. 101

elegans.................................. 96

Anisonchus................................. 102

gillianus................................. 92

sectorius................................. 92

Anthracotheriidoj........................... 55,

60,61,62,63,64,69,104,1C6,109, 111 

Anthracotherium............................ Ill

curtum..........................:....... 106

karense.................................. 109

sp........................................ 104

Antiacodon................................. 96,101

Antilocapra.............................. 85,80,87

121
122 INDEX.

Page. 

Antilocapridae............... 77,86,114,115,118,120

Apatemyidse............................... 96,101

Apatemys................................... 101

bellulus................................. 96

bellus................................... 96

Aphelops................................ 78,81,119

brachyodus.............................. 116

ceratorhinus............................ 80,116

jemezanus............................... 116

malacorhinus... ......................... 81,116

megalodus............................... 114

oregonensis.............................. 114

planiceps................................ 114

profectus................................ 114

Aplodontiidse. ./!..................... 107,110,119

Apternodus................................. 110

medisevus............................... 103

Aquitanlen etage, homotaxis and fauna of... 67-75 

Aralia................... .^.................. 78

Archselurus................................. 68

Archseohippus............................. 78,119

ultimus................................. 115

sp....................................... 115

Archaic mammals, elimination of............ 35

orders of................................. 33

Archer, Fla.', fauna at..................... 115-118

Arctocyonidse......... -33,34,35,40,42,45,91,93,100

Arctomys................................... 90

Arctoryctes................................ 75,118

terrenus................................. 112

Arctotherium............................... 87,89

Arikaree formation, correlation of........... 71

fauna of................. 70-75,112-114,115-118

homotaxis of............................ 70-75

figure showing....................... 70,72

Arretotherium.............................. Ill

acridens................................. 109

Artiodactyla..... 33,36,38,40,42,52,54,55,56,57,58,

59, 60, 61, 62, 63,64,66,68,69,73,74,75,77,80,

81, 83, 85, 86, 88-89,90,95,98,99-100,103,104,

106,108-109,111, 113-114,115,117-118,119,120

Arvicola..................................... 85

Astien 6tage, homotaxis and fauna'of........ 82-83

B. 

Banding, occurrence of...................... 27-28

Bartonien 4tage, homotaxis and fauna of..... 50-57

Bassariscus.................................. 89

Bathygenys................................. Ill

alpha.................................... 104

Bathyopsis........................... 44,45,47,102

flssidens.................................. 94

Bathyopsis zone, fauna of............. 43-48,92-95

homotaxis of ............................ 43,48

figure showing....................... 44

Beds, use of term............................ 7

Beede, J. W., and Haworth, E., paper by.... 17

Bibliography ot western Cenozoic horizons... 9-18 

Bighorn Basin, Wyo., fauna of........... 42,92-95

sections of, figures showing.............. 23,38

Bison....................................... 87,89

occidentails............ ................ 88

Blacktail Deer Creek, Mont., fauna of...... 106-109

Blanco formation, fauna of.............. 82-83,120

homotaxis of............................ 82-83

figure showing....................... 82

Page. 

Blarina...................................... 90

Blastomeryx................ 70,72,74,75,80,81,120

advena.................................. 120

gemmifer............................... 115

wellsi................................... 118

sp....................................... 114

Bolodontidse............................... 91,100

Boochosrus.................................. 108

Borophagus.............................. 80,83,86

diversidens.............................. 120

Bovidae............................ 85,86,88,89,90

Bo vinse..................................... 86

Bozeman lake beds, character of............. 24

Brachyprotoma............................. 90

Brachypsalis............................ 74,80,118

pachycephalus.......................... 116

simplicidens............................. 112

Bridger Basin, Wyo., section of, figure showing.............................. 23

Bridger formation, character of.............. 25-26

distribution of, map showing............ 37

fauna of.......................... 50-53,95-100

homotaxis of............................. 50-53

figures showing................... 23,39,51

Brontotheriidse.................. 95,98,100,104, 111

Brontotherium.............................. Ill

bucco................................... 104

curtum.................................. 104

dolichoceras............................. 104

gigas.................................... 104

hypoceras....................:.......... 104

leidyi................................... 104

platyceras............................... 104

ramosum................................ 104

Brown, Barnum, on Port Kennedy cave

fauna............................. 87

Brule clay, distribution of, plates showing... 7,60 

fauna of......................... 62-68,105-109

homotaxis of........................... 62-68

figures showing...................... 62,64

Buffalo basin, deposits of.........'........... 41

Bunaelurus................................. 63,110

" infelix................................... 103

lagophagus.............................. 105

Bunodonta.................................. 52

Bunomeryx................................. 103

elegans..........:....................... 99

montanus............................... 99

Burdigalien 6tage, homotaxis and fauna of... 70-75

C.

Cadurcotherium............................. 62

Csenopus.................................. Ill, 119

annectens............................... 108

copei.................................... 105

mitis.................................... 104

occidentalis.............................. 105

pacificus................................ 108

persistens............................... 114

platycephalus....... '.................. 104,108

simplicidens........... 1................. 105

tridactylus.............................. 108

truquianus.............................. 108

tubifer.................................. 108

sp....................................... 104
INDEX. 123

Calamodon................................. 40,102

arcamcenus.............................. 94

novomexicanus.......................... 94

simplex................................. 94

Galops....................................... HI

censors................'.................. 109

cristatns................................. 109

Camelidse............................. 57,61,03,64,

66,67,08,73,74,75,76,78,80,81,83,85,80,87,89

90,100,103,104,106, 109, 111, 114, 115, 117, 120

Camelomeryx............................... 100

Camelops.................................... 86

Camel us............................... 85,80,87,89

Canada, fauna of........................... 103-105

Canidaj............................ 46,52,56,60,61,

63,66,08,73,74,77,78, 80, 81, 83, 85, 80, 89, 90,

99,103,105,106-107, 110, 112, 114, 115, 118, 120

Car.imartes.................................. 83

ciunminsii .............................. 120

Canis.............................. 83,85,89,90,118

anceps ....................- - -- - ! 14

temerarius............................. 114,115

vafer.................................... 115

sp........................................ 114

Canyon Ferry, Mont., fauna near.......... 112-114

Capromeryx................................. 86,87

Carcinodon.................................. 101

fllholianus............................... 91

Carnivora................................... 33,

35,40,42,45,46,52,54, 56, 57, 58, 59, 60, 61, 63,

68,74,75,77,80,81,83,85,86,89,90,93,96,98-99,

100-101,103,105,110,112, 114, 115-116, 118, 120

Castor.................................... 83,85,90

Castoridffl..........,..............'.......... 61,64

66,68,73,74,81,103,105,107,110,112,110,118 

Castoroides.................................. 85

Catopsalis................................... 100

foliatus,................................. 91

Cedar Creek, Colo., fauna of............... 105-106

Ceneutheria................................. 33

Centetes.................................... 01

Centetlidaj.................................. 52

Centetodon.................................. 101

altidens................................. 96

pulcher.................................. 96

Centetodontidfe.................. ; ......... 96,101

Centracodon................................. 101

delicatus................................ 96

Ceratogaulus............................... 78,119

rhinocerus................................ 114

Cernaysien 6tage, homotaxis and fauna of... 34-35 

Cervidse.... 74,75,77,78,80,81,86,89,90,115,118,120

Cervus................................... 86,87,89

canadensis............................... 90

Chadron, S. Dak., fauna of................ 103-104

Chadron formation, distribution of, plate

showing......................... 7,60

fauna of.................:....-. 60-61,103-104

homotaxis of............................ 60-61

figures showing...................... 62,64

Chtenohyus................................. Ill

decedens................................ 109

Chalicotheriidfe............................ 55,60,

' 61,62,66,67,69,74,81,104,108,111,113,115,119 

Chalicotheriiun bilobatum................... 104

Cheiroptera.............. ................... 45,56

Page. 

Chelydridse.................................. 58

Chirox...................................... 100

plicatus................................. 91

Chriacus..................................'... 101

" baldwini................................ 91

pelvidens................................ 91

schlosserianus........................... 91

truncatus................................. 91

Chrysochloridfe................. 75,103,110,112,118

Clsenodon................................... 100

corrugatus............................... 91

ferox................................... 91

protogonioides .......................... 34,91

Clarendon, Tex., fauna near............'... 115-118

Clark, W. B., papers by..................... 9

Clemmys.................................... 58

hesperia................................. 81

Cockerell, T. D. A.., paper by............... 13

Colodon..................................... Ill

cingulatus............................... 105

dakotensis............................... 105

longipes................................. 105

occidentalis.............................. 104

procuspidatus........................... 105

Colonoceras.................................. 102

agrestis.................................. 97

Colonomys.................................. 101

celer..................................... 97

Colorado, fauna of................... 92-98,103-109

formations in, homotaxis of.............. 22

figure showing....................... 23,65

Conacodon.................................. 102

cophater................................. 92

entoconus............................... 92

Conard fissure, Ark., fossils of........... ... 90

Condylarthra.......... 33,35,40,41,42,45,92,94,102

Conoryctes.................................. 102

comma.................................. 92

Conoryctidae............................ 34,92,102

Cope, E. D., on archaic mammals........... 34

on Loup Fork beds...................... 84

papers by......................... 10,11,13,17

Cope, E. D., and Wortman, J. L., paper by.. 17 

Correlation, attempts at................. 8-9,31-32

methods of.............................. 30-31

problems of.............................. 29-30

progress of................................ 8-«

Coryphodon.............. 38,40,41,44,45,47,48,102

armatus................................. 94

curvicristis.............................. 94

elephantopus............................ 94

hamatus................................. 94

latidens................................. 94

lobatus.................................. 94

radians.................................. 39,94

semicinctus.............................. 39

singularis................................ 94

testis.................................... 94

ventanus................................ 49,94

wortmani................................ 94

Coryphodon zone, fauna of................ 40,92-95

homotaxis of......................... 23,36-40

figures showing................... 23,38,39

Coryphodontidoe...... 35,37-38,40,41,42,45,94,102

Creodonta.......... 33, 35, 37,40,42,45,52,54,56,57,

59,60,62,66,91,93,96,98,100-101,103,105,110
124 INDEX.

Page.

Crocodilus................................... 47

Cummins, \V. F., paper by.................. 13

Cyclopidius................................. 78,114

decedens................................ 115

emydinus............................... 115

incisivus................................. 115

simus.........................-...--.---- H5

Cvlindrodon................................. HO

fontis.................................... 103

Cynarctus................................... 78

saxatilis................................. 114

Cynodesmus............................. 75,80,118

brachypus............................... 112

minor................................... 112

thomsoni................................ 112

thooides................................. 112

Cynodictis............................ 57,61,63,110

gregarius................................ 105

lippincottianus.......................... 105

oregonensis.............................. 106

paterculus............................... 103

temnodon............................... 106

sp....................................... 103

Cynodon.................................... 110

Cynodontomys.............................. 100

angulatus... ..-........................... 93

latidens................................. 93

sp....................................... 93

Cynomys................................... 85,118

sp....................................... 116

Cyon......................................... 118

sp....................................... 114

D.

Dsemonelix beds, homotaxis and fauna of... 73-74 

honiotaxis of, figure showing............ 72

Dffiodon..................................... 108

Ball, W. H., papers by................... 10,13,29

Ball, W. II., and Harris, G. D., paper by.... 13

Daphaanus.............................. 01,63,110

dodgei................................... 103

felinus................................... 105

hartshornianus.......................... 105

nebrascensis............................. 105

vetus.................................... 105

sp....................................... 103

Darton, N. U., on Monument Creek formation. ............................ 61

papers by.......................... 11,13,14,19

Dasypoda.......... a................. 33,43,50,52

Dasypodidee................................. 31

Davis, W. M., papers by.................... 10

Dawkins, W. B., papers by.................. 10

Deep River, Mont., fauna of............... 114-115

Deep River sequence, fauna of....... 76-78,114-115

. homotaxis of............................ 76-78

Deltatherium................................. 101

fundaminis............................... 91

Depe"ret, Charles, correlation by............. 8-9

Deposition, stages of, character of............ 22

Dermatemydidae............................. 58

Desmathyus.....................'........ 74,75,119

pinensis................................. 113

siouxensis............................... 113

sp....................................... 113

Desmatotherium............................. 102

guyotii................................... 98

Page.

Diacodon.................................... 101

alticuspis................................ 93

celatus.................................. 93

Dibelodon................................... 120

humboldtii.............................. 120

mirificus............................. 82,83,120

praecursor............................... 120

tropicus................................. 120

Diceratheriinae..:............ 59,64,67,68,69,75,77

Diceratherium.... 61,68,70,72,73,74,75,108, 111, 119

armatum................................ 108

cooki.................................... 113

nanum.........................:........ 108

niobrarense.............................. 113

sp....................................... 113

Diceratherium zone, fauna of........ 67-68,106-109

homotaxis of............................ 64,67

figures showing.................. 23,65,67

Dichobunidae.............. 36,57,95,98,99,103,106

Dicotylidae ...... 59,61,63,66,68,74,75,80,81,83,86,

87,89,90,104,106,109, 111, 113,115,117,119,120

Didelphodus............................... 49,101

absarokse................................ 93

Didelphyidae.................. 55,59,61,103,105,110

Didymictis................................. 46,100

altidens................................. 49,93

haydenianus............................ 91

leptomylus.........'..................... 93

protenus................................ 93

Dilophodon................................. 102

minuseulus.............................. 98

Dinictis..................................... 110

bombifrons............................... 107

Cyclops.................................. 107

fellna......................'.............. 105

fortis.................................... 103

paucidens............................... 105

squalidens............................... 105

sp....................................... 103

Dinoceras. See Uintatheriiim.

Dinocerata......................... 47,52,54,50,57

Dinocyon............................ 80,81,80,118

gidleyi.................................. 115

mseandrinus.............................. us

ossifragus................................ 115

ursinus.................................. 115

j Dinohyus............................... 72,74,108

hollandi..........................._...... 113

Diplacodon.................................. 102

elatus................-.-.:.-............... 99

emarginatus............................. 99

sp....................................... 99

Diplacodon zone, fauna of............ 55-57,98-100

homotaxis of......................... 22,54-55

figures showing...................... 23,56

Dipodidse................................... 107

Dipoides...........:....................... 81,118

tortus................................... 116

Dlssacus........"....!...................... 35,101

leptognathus............................ 93

navajovlus.............................. 91

saurognathus...........................: 91

Dolichorhinus............:.................. 102

cornutus.............................. 54,57,99

sp....................................... 99

Domnlna crassigenis.....'.................... 105

gradata. ...........~..................... 105
INDEX. 125

Page. 

Dorcatherium aquaticum.................... 46

Douglass, Earl, papers by ................ 11,14,19

Drainage, changes in........................ 21,24

.Drornocyon vorax........................... 96

Drummond, Mont., fauna near............ 106-109

Dryptodon.................................. 102

crassus.................................. 94

Earle, Charles,and Osborn, H. F., paper by. 12 

Ectocion.................................... 102

osbornianus............................. 94

E.ctoconus................................... 102

ditrigonus............................... 92

Ectoganus................................... 102

gliriformis............................... 94

Edentata ..........'... 33, 34,35,40,43,45,46,52; 59,

78,82, 83, 85,86,87,89,90,97,102,114,119,120 

Elephantidaj...:...................... 116,119,120

Elephantine................................ 86,87

Elephas.................................. 82,83,87

columbi........................ 85,86,87,88,89

imperator................... 79,83,84,85,86,87

meridionalis............................. 83,85

primigenius....................... 86,87,88,89

Elephas imperator zone, fauna of............ 83-84

homotaxis of............................ 83-84

Elotheriidte................................ 54,57,

06,68,69,74,75,77,104,100,108, 111, 113,119 

Elotheriinse...............................:. 61,63

Elotherium................. 59,67,69,70,75,108,119

bathrodon............................... 108

calkinsi................................. 108

 coarctatum............................... 104

crassum...............'.......!... 104,106,108

imperator............................... 108

ingens................................. 106,108

mortoni................................. 106

sp................................. 104,108,113

Emydidse................................... 58

Enhydrocyon.......................... 75, 111, 118

basilatus.............................'... 107

crassidens............................... 112

sectorius................................. 107

stenocephalus........................... 107

Entelodon. See Elotherium.

Entelodontidaj. SeeElotheriidse.

Entelodon tinee.............................. 61

Entomacodon angustidens................... 96

minutus................................. 96

Entoptychus............................ 68,75,110

cavifrons................................ 107

crassiramis.............................. 107

curtus................................... 112

formosus................................ 112

lambdoideus............................ 107

mjnor................................... 107

planifrons............................... 107

rostratus................................ 107

sperryi.................................. 107

Eobasileidfe..........'................ 94,97,99,102

Eobasileus........................... 54,56,97,102

cornutus................................ 99

furcatus................................. 99

galeatus................................. 99

pressicornis............................. 99

sp...................:................... 99

Page.

Eobasileus zone, fauna of....... 53-54,55-57,98-100

homotaxis of...................... 22,53,54-55

figures showing.................'.. 23,53,56

Eocene, distribution of, plate showing....... 7,60

fauna of.......................... 33-57,91-103

range of........................... 100-103

homotaxis of............................ 33-57

records of............................... 26

Eocene, basal, fauna of........ 33-35,91-92,100-103

homotaxis of............................ 33-35

Eocene, lower, fauna of........ 35-50,92-95,100-103

homotaxis of............................ 35-50

Eocene, middle, fauna of...... 43-54,95-98,100-103

homotaxis of............................ 43-54

Eocene, upper, fauna of.............. 53-57,98-103

homotaxis of......... '. .................. 53-57

Eocene-Oligocene correlation, progress of.... 31

Eohippus................... 38,41,44,45,46,47,102

angustidens............................. 95

borealis................................. 95

craspedotus............................. 95

cristatus ................................ 38,95

cristonensis............................. 95

cuspidatus.............................. 95

index................................... 39,95

montanus.... 1.......................... 95

pernix.................................. 95

resartus................................. 95

. validus.................................. 95

vassaciensis. .1.......................... 39,95

venticolus............................... 95

sp....................................... 49

Eohippus zone, homotaxis of................ 23

Eohyus distans............................. 94

robustus................................ 94

Eolian theory, history of.................... 27

Eotitanops.............................. 44,45,102

borealis.. ......................... 44,46,48,95

brownianus............................. 46,95

Eotitanops zone, homotaxis of............... 23

Epigaulus.................................. 81,119

hatcheri................................. 116

Epihippus.................................. 102

gracilis.................................. 99

parvus.................................. 99

uintensis................................ 99

Eporeodon.................... 04,68,75,78,111,119

leptacanthus............................ 109

longifrons............................... 109

major................................... 109

occidentalis............................. 109

pacificus................................ 109

socialis.............:.................... 109

trigonocephalus......................... 109

sp..................................... 109,113

Equidaj... 30,38,40, 41,46,52,54,57,01,63,64,66,67, 

68,74,75,76,78,80,81,83,85,86,87,89,90,95,98, 

99,102,104,106,108, 111,113, 115,117, 119,120

EquiniB..................................... 86

Equus.......................... 82,83,85,87,89,90

excelsus................................. 83,84

stenonis................................. 83

Equus zone, fauna of........................ 85,86

homotaxis of............................ 85

figure showing...................... 82
126 INDEX.

Page. 

Erethizon................................ 87,88,90

dorsatus................................. 90

Erinaceidaj............................. 52,105,110

Erosion, retardation of...................... 21

Eschatius.......'............................ 86

Esthonyx............................ 38,45,46,101

acer..................................... 94

acutidens................................ 94

bisulcatus............................... 94

burmeisteri.............................. 94

spatularius.............................. 94

Eucastor.................................... 118

tortus................................... 110

Eviceratherinm.............................. 89

Eucrotaphus. See Eporcodon.

jacksoni .......................'......... 109

Euhapsis................................... 75,118

brachyceps.............................. 112

gaulodon................................ 112

platyceps............................... 73

Eumys...................................... 110

elegans.................................. 105

Euprotogonia.............................. 40,102

Eurasiatic-American correlation, problem of. 29-30 

European-American faunas, correlation of... 59 

Euryacodon................................ 100

lepidus.................................. 95

Eusmilus................................... 110

dakotensis.............................. 107

Eutypomys....................4............. 110

thomsoni................................ 105

sp....'................................... .103

Evanston formation, section of, figure showing.............................. 39

Fauna localities, location of, map showing.... 7

Felidae............. 60,61,63,66,68,77,80,83,85,89,

90,103,105,107,110,112,114,116,118,120 

Felinaj...................:............ 64,77,81,90

Felis............................... 80,83,85,88,90

canadensis.............................. 89

concolor..........................'....... 89

hillianus............................... 83,120

Fiber....................................... 85,90

Ficus ....................................... 78

Field work, character of..................... 19

Filhol, H., papers by........................ 10

Fissipedia............... 33,99,103,105,106-107-110

Flint Creek, Mont., fauna of............. 114-115

Flood-plain theory, history of................ 26-28

Florida, formations in, homotaxis of, figure

showing......................... 65

Formation, definition of..................... 7-8

Formation names, form of................... 8

Formations, mountains and plains, homotaxis of.......................... 22

Fort Logah, Mont., fauna near............. 112-114

Fort Niobrara, Nebr., fauna near.......... 115-118

Fort Union, Mont., section at, figure showing. 23 

Fort Union formation, fauna of.............. 91-92

homotaxis of, figure showing............ 23

Fowkes formation, homotaxis of, figure show-

-ing.............................. 39

Furlong, E. L., papers by................... 17

G Page. 

Geolabis rhynclweus........................ 105

Geological Survey, rulings of, on formation

names........................... 8

Geomyidse.................................. 61,

66,68,75,99,101,107,110,112,114,116,119 

Geomys................................. 85,90,119

bisulcatus............................... 116

sp........................................ 114

Gering formation, homotaxis and fauna of... 73 

homotaxis of, figure showing............ 72

Gidley, J. W-, paper by..................... 14,21

Gidley,J. W., and Matthew, W. D., paper by. 15 

Gilbert, G. K., papers by................... 10,14

Gilbert, G. K., and Hall, J., paper by....... 17

Glacial epoch, homotaxis and 'fauna of....... 86-90

Glyptodontia............................ 82,83,86

Glyptodontidae............................. ' 120

Glyptosaurus............................... 47,49

Glyptotherium.............................'. 83

texanum................................ 120

Glyptotherium zone, fauna of.......... 82-83,120

homotaxis of............................ 82

figure showing................... 23,65,82

Gomphotherium. See Trilophodon.

Goniacodon................................. 101

levisianus............................... 91

Gravigrada............................ 78,82,86,87

Great Plains, dry-land conditions in......... 57-58

Green River formation, homotaxis of, figure

showing......................... 39

Gymnoptychus............................. 110

minimus................................ 104

minutus............................... 104,105

trilophus................................ 105

H.

Hall, J., and Gilbert, G. K., paper by....... 17

Hapalodectes............................... 45,101

leptognathus............................ 93

sp....................................... 93

Haploceras.................................. 87,89

Haploconus................................. 102

corniculatus............................ 92

lineatus................................. 92

Haplodontidae............................ 64,66,68

Harpagolestes............................... 101

macrocephalus.......................... 96

uintensis................................ 98

sp....................................... 98

Harris, G. P., and Dall, W. H., paper by.... 13

Harrison, Nebr., fauna near............... 112-114

Harrison formation, homotaxis and fauna of. 73-74 

homotaxis of, figure showing............ 72

Hatcher, J. B., papers by................ 14,17,19

Haworth, E., paper by...................... 15

Haworth, E., and Beede, J. W., paper by... 17 

Hay, 0. P., on Great Plains................. 57-58

paper by................................ 11

Hay, R., paper by.......................... 15

Hayden, F. V., on Washakie basin.......... 53

on Wind River formation............ 44-45,47

papers by............................... 11

Helaletes................................... 99,102

boops................................... 98
INDEX. 127

Page. 

Helaletes, nanus............................ 98

sp....................................... 98

Helaletinse.................................. 41,54

Helohippus................................. 102

Helohyus................................... 103

ctsagicus................................ 95

Icntus................................... 98

plicodon................................ 98

validus.................................. 98

sp....................................... 98

1:1 clothcriimi................................ 102

Helve tieu 6tage, homotaxis and fauna of..... 70-78

Hcmiacodon................................ 100

gracilis.................................. 05

pygmaeus............................... 95

Hcmipsalodon grandis.................... 103,110

Hemithlaeus................................. 102

kowalevskianus......................... 92

Heptodon............................ 38,41,40,102

calciculus............................... 9,4

posticus................................. 94

singularis............................... 94

ventorum.........:..................... 94

sp....................................... 99

Herbivora................................... 80

Hesperomys................................. 318

loxodon ................................. 110

Hesperhys............................. T .... 119

 vagrans................................. 115

Heteromeryx............................... Ill

dispar................................... 104

transversus............................. 104

Heteromyidte.............................. 57,119

sp....................................... 112

Hills, R. C., papers by...................... 11

Hipparion.................................. 79,83

Hippotheriina:.............................. 78

Holarctica, invasion from................... 35-36

Hollick, Arthur, on Mascalt flora............ 78

Homacodon................................ 98,103

vagans.................................. 98

sp....................................... 98

Homacodon tidae............................ 57,98

Homo.................................... 88,89,90

Homogalax. See Systemodon.

Hoplophoneus.............................. 110

cerebralis................................ 107

davisi................................... 107

insolons................................. 107

occidentalis............................. 105

oreodontis............................... 105

primsevus............................... 105

sp....................................... 105

Horizons, phases of, homotaxis and faunae... 33-90 

time correlation of....................... 29-32

Horsetail Creek, Colo., fauna of............ 103-104

Huerfano formation, fauna of.......... 48-50,95-98

homotaxis of............................ 48-50

figure showing...................... 23

Huerfano Park, Colo., deposits of............ 48

fauna of................................. 92-95

section of, figure showing................ 23

Hysenidae................................... 04

Hysonodon............................. 59,103,110

crucians................................. 105

cruentus................................. 105

Page.

Hysenodon horridus......................... 105

leptocephalus............................ 105

montanus............................... 105

mustelinus.............................. 105

pauciden s .............................. 105

Hysenodontidse.................... 40,45', 46,32,54,

57,60,61,62,63,00,93,96,101,103,105, 110

Hyohippus.................................. 78,82

Hyomcryx.................................. 103

breviceps................................ 100

Hyopotamus...................... 59,61,62,04, 111

americanus.............................. 104

brachyrhinchus.......................... 109

rostratus................................ 106

HyopsodontidiO.......... 40,52,59,92,93,90,99,101

Hyopsodus..................... 38,40,44,45,47,101

browni.................................. 93

gracilis.................................. 99

jacksoni................................. 93

laticuneus............................... 93

lemoinianus............................. 93

marshi ^................................. 96

minor................................... 93

minusculus............................... 96

miticulus................................ 93

paulus.................................. 96

powcllianus............................. 93

simplex................................. 93

uintensis................................ 99

wortmani............................... 93

sp.................................... 49,93,96

Hypertragulidte ................ 57,01, C3,64,68,74,

75,77,100,103,104,106,109, 111, 114,120

Hypertragulus...................... 70,75,111, 120

calcaratus............................. 106,114

hesperius................................ 109

ordinatus............................... 114

planiceps................................ 109

sp....................................... 109

Hypisodus................................. 74, 111

minimus................................ 106

Hypohippus............................. 80,81,119

affinis................................... 117

equinus................................. * 115

osborni.................................. 115

sp..................................... 115,117

Hyrachyus................................. 49,102

agrarius.................................. 97

bairdianus.............................. 97

crassidens............................... 97

eximius.................................. 97'

imperialis............................... 97

intermedins............................. 97

paradoxus............................... 97

princeps................................ 97

prisons.................................. 99

sp....................................... 97

Hyracodon.................................. Ill

arcidens................................. 105

major................................... 105

nebrascensis............................. I0.r>

planiceps................................ 105

priscidens............................... 104

sp....................................... 108

Hyracodontida;............................ 52,

54,57,61,63,99,102,104,105,108, 111
128 INDEX.

Page. 

Hyracoidea.................................. 33

Hyracops................................... 102

Hystricomorpha............................ 88,89

I.

Icticyon sp.................................. 114

Ictops....................................... 110

acutidens............................... 103

bullatus................................ 105

dakotensis.............................. 105

intermedius............................. 103

major................................... 103

montanus.................:............... 103

porcinus................'................. 105

tenuis................................... 103

thompsoni............................... 103

Indrodon................................... 35,101

malaris.................................. 92

Insectivora........................... 33,34,40,45,

46,52,56,58,59,61,63,64, 75,90,92,93, 

 95,96,99,101,105,107,110,112,114,118

Irving, J. D., paper by...................... 15

Ischyrocyon................................ 80,118

hysenodus............................... 115

Ischyromyidse.............. '............... 54,57,

61,63,66,94,97,99,101,104,105,110

Ischyromys................................ 61,110

cristatus................................. 105

typus................................... 105

veterior................................. 104

Isectolophus................................ 102

annectens............................... 99

latidens................................. 98

modestus................................ 98

Ithygrammodon..............;.............. 103

cameloides............................... 98

J.

John Day, Oreg., fauna of................. 106-109

John Day formation, fauna of........ 64-69,106-111

homotaxis of......................... 22,64-69

figures showing................... 23,65,67

Johnson, W. D., papers by.................. 10

K. 

King, on volcanic ash......"................. 24

Knight formation, homotaxis of, figures

showing......................... 23,39

Knowlton, F. H., paper by.................. 15

Lacertilia.................................... 47

Lacustrine theory, history of................ 26-28

Lambdotherium............ 41,44,45,46,47,48,102

popoagicum....................... 46,47,49,95

primsevum.............................. 38,48

Lambdotherium zone, fauna of..... 43-47,49,92-95

homotaxis of...................... 22,43,47,48

figures showing................... 23,38,44

Laramie formation, homotaxis of, figure

showing......................... 39

Laramie Peak, Wyo., fauna near.......... 112-114

Laurus...................................... 78

Leidy, J., on Loup Fork fauna.............. 83

Leidy, J., and Lucas, F. A., paper by....... 15

Leporidse..... 61,66,68,104,105,108,110,113,116,119

Page.

Leptaceratherium........................... Ill

trigonodon............................ 104,105

Leptarctus................................. 80,118

primus.................................. 116

Leptauchenia'...... 64,66,69,70,72,73,75,78, 111, 119

decora.................................. 73,113

major................................... 113

nitida.................................. 73,113

sp.................................. 106,109,113

Leptauchenia zone, fauna of......... 63,64,106-109

homotaxis of............................ 63

figure showing................. 23,62,64,65

Leptictida...... 45,46,52,61,93,96,101,103,105,110

Leptictis.................................... 110

haydeni................................. 105

Leptochceridaj.............. 63,69,104,100,109, 111

Leptochcerus................................ Ill

gracilis.................................. 106

lemurinus............................... 106

robustus................................. 106

spectabilis............................... 106

sp....................................... 109'

Leptomeryx................................ Ill

esulcatus..........'...................... 104

evansi................................... 106

transmontanus.......................... 109

sp..................................... 104,106

Leptoreodon................................ 103-

marshi.................................. 100

Leptotragulus............................. 103,111

loevis.................................... 100

proavus................................. 100

profectus................................ 104

sulcatus................................. 100

sp....................................... 100

Lepus.........................'.... 68,75,85,90,110

ennisianus............................... 108

macrocephalus-.......................... 113

primigenius............................. 113

sp........................................ 116

Ligurien dtagc, homotaxis and fauna of...... 54

Limnenetes................................. Ill

anceps.................................. 104

platyceps............................... 104

Limnocyon................................ 45,100

verus.................................... 96

sp.................................... 93,96,98

Limnohyops................................ 102

diaconus................................ 98

laticeps................................. 98.

Little White River, S. Dak., fauna of...... 115-118

Loomis, F. B., on Bighorn Basin ............ 41

on Wind River formation............... 47

papers by............................... 11,15

Lophiodon oregpnensis..................... '. 108

Lophiodontidse........ 30,38,40,41,46,52,54,57,61,

63,94,98,99,102,104,105, 111 

Loup Fork fauna, identity of............. 79,83-84

Lower Brule Creek S. Dak., fauna of...... 105-106

Loxolophodon.............................. 54

semicinctus............................. 54

Loxolophus................................. 101

attenuatus.............................. 91

hyattianus.............................. 91

priscus................................... 71

Lucas, F. A., and Leidy, J., paper by ......*.. "15
INDEX. 129

Page.

Ludicn dtage, homotaxis and fauna of. 54,57.00-61 

Lutdticn 6tage, homotaxis and fauna of...... 43-5 3

Lutra................................... 80,85,118

pristina... ............................. 116

Lynx........................................ 89,90

M. 

Machacrodus.................................. 118

augustus................................ 116

catocopis................................ 116

crassidens............................... 116

maximus................................ 118

Machfcrodontinsc.......... 60,61,63,81,86,87,89,90

McMastcr, J. B., paper by................... 12

Macrotherium............................... 69

Madison Valley, Mont., fossils of........... 115-118

Mammalian life, phases of................... 20

Manteoceras................................ 53,102

manteocoras............................. 98

ultimus.................................. 99

sp....................................... 99

Marsh, O. C., papers by..................... 10

Marsilea..................................... 78

Marsupialia................ 33,55,59,61,103,105,110

Martin Canyon, Colo., fauna of.... 106-109,112-114

Mascall, Oreg., fauna of.................... 114,115

Mascall formation, homotaxis and fauna of. 22,64,78 

homotaxis of, figure showing............. 23

Mastodon.............................. 69,83,87,89

americanus.............................. 86

mirificus................................. 83,84

Mastodontidtc............................... 81

Matthew, W. D., correlation by...........' 8,29,69

on Bruleclay............................ 62,63

on faunal persistence.................... 42

on Great Plains deposition............... 27

on Miacidce.............................. 52

on Eosebud beds........................ 75

papers by............................ 11,15,17

Matthew, W. D., and Gidley, J. W., paper

by.........:..................... 15

Meek, F. B., and Hayden, F. V., on Loup

Fork beds....................... 83

Megacerops.................................. Ill

angustigenis............................. 104

bicornutus.............................. 104

brachycephalus.......................... 104

coloradensis...................:......... 104

dispar................................... 104

marshi.................................. 104

robustus................................. 104

selwynianus............................. 104

tichoceras............................... 1Q4

Megalictis.................................. 75,118

fcrox.................................... 112

Mcgalonychid*........................ 114,119,120

Megalonyx......................... 82,83,87,88,89

loptostoma.............................. 120

Meniscomys............................. 68,75,110

sp....................................... 112

Meniscotheriidac......................... 40,94,102

Meniscotherium............................. 102

chamense................................ 94

tapiacitis................................ 94

terrasrubraj.............................. 94

56092 Bull. 361 09 9

Mephitis..................................... 89,90

Mercer, H.. C., paper by...................... 18

Merriam, J. C., on volcanic ash.............. 25

papers by............................. 15,18,19

Merychippus......................... 78,79,80,119

calamarius.............................. 117

campestris....... I....................... 115

insignis.................................. 117

isonesus................................. 115

labrosus..............................'... 115

paniensis................................ 115

sejunctus................................ 115

seversus................................. 115

sphenodus............................... 115

Merychippus zone, homotaxis of............. 64

Merychyus........ C9,70,72,74,75,78,80,81,113,119

elegans................................ 113,117

harrisonensis............................ 113

major.................................... 117

medius.................................. 117

pariogonus............................... 115

smithi................................... 115

sp..................................... 115,117

Merycochcerus............. 09,70,72,74,75,78,80,81

cenopus................................. 117

proprius................................. 115

rusticus................................. 115

sp..................................... 113,117

Merycochosrus zone, homotaxis of, figures

showing............. 23,64,65,70,72,82

Merycodontina;........ 77,80,81,80,114,115,118,120

Merycodus....................'....... 77,80,81,120

agilis.................................... 118

furcatus................................. 118

necatus.................................. 118

osborni.................................. 115

ramosus................................. 118

tehuanus................................ 118

Merycoides.................................. 119

cursor................................... 113

Merycoidodon. See Oreodon.

Mesatirhinus................................ 51

megarhinus........................... 52,53,54

Mesocyon............................ 68,75,110,118

brachyops............................... 107

coryphaeus................:............. 106

drunimondanus......................... 107

josephi.................................. 106

robustus................................. 112

sp....................................... 112

Mesodectesi................................. 110

caniculus................................ 105

Mesogaulus.................................. 119

ballensls................................ 114

Mesohippus................................. Ill

acutidens.............................. 68,108

assiniboiensis............................ 104

bairdii.................................. 106

brachylophus........................... 108

brachystylus.......................... 104,108

celer.................................... 104

equiceps................................ 108

eulophus................................ 106

exoletus................................. 106

hypostylus.............................. 104
130 INDEX.

Page.

Mesohippus, intermedius................... 108

latidens................................. 104

longicristis............................... 108

montanensis............................ 104

obliquidens............................. 106

precocidens............................. 104

planidens...............:...........'.... 104

proplnquus............................. 104

proteulophus............................ 104

stenolophus............................. 104

Mesonychidse........................... 33,34,35,

37,40,45,46,52,54,57, 90, 91, 93, 96, 98, 101

Mesonyx obtusidens........................ 96

sp....................................... 98

Mesoreodon. ........ :................ 72,73,75,119

chelonyx................................ 113

intermedius............................. 113

latidens................................. 113

megalodon............................... 113

Mesotapirus. See Colodon.

Messinien 6tage, homotaxis and fauna of.... 80

Metacheiromyidse.......................... 97,102

Metacheiromys.-i....................... 50,52,102

dasypus.. ............................... 97

marshi.................................. 97

tatusia.................................. 97

sp....................................... 97

Metamynodon.............................. 62,111

platyfrons................... ........... 105

sp...................................... 99,104

Metamynodon sandstones, fauna of.......... 63

homotaxis of............................ 62

figures showing............... 22,62,64,65

Miacidse .. 35,40,42,46,52,54,57,90,91,93,96,98,100

Miacis...................................... 46,100

hargeri.................................. 96

parvivorus.............................. 96

sylvestris............................... 96

uintensis................................ 98

vulpinus................................ 98

washakius.............................. 96

sp....................................... 93,96

Microclsenodon............................. 101

assurgens............................... 91

Micropternodus............ ................ 110

borealis..................... ........... 103

Microsorex.................................. 90

Microsus................................... 98,103

cuspidatus.............................. 98

Microsyopidse..................... 46,52,93,95,100

Microsyops................................. 49,100

annectens............................... 95

elegans.................................. 95

schlosseri................................ 95

scottianus............................... 93

typus.......... ........................ 95

sp....................................... 95

Microtus.................................... 90

Miocene, distribution of, plates showing..... 7,60

fauna of......................... 70-81,112-120

homotaxis of............................ 70-81

figures showing...................... 64,65

Miocene, lower, fauna of..... 70-75,112-114,118-120

homotaxis of............................ 70-75

figure showing....................... 65

Page.

Miocene, middle, fauna of.... 76-78,114-115,118-120

homotaxis of............................ 76-78

figure showing....................... 65

Miocene, upper, fauna of............. 79-81,115-120

homotaxis of............................ 79-81

figure showing....................... 65

Mioclaenus.................................. 34,101

acolytus................................. 92

insequidens.............................. 92

lemuroides.............................. 92

lydekkerianus........................... 92

turgidunculus........................... 92

turgidus ................................ 92

Miohippus................................... Ill

anceps................................... 108

annectens............................. 108,113

condoni................................. i.08

crassicuspis.................'. ........... 108

equiceps................................. 113

gidleyi................................... 108

validus.................................. 108

Miolabis ............................. 66,74,78,120

transmontanus.......................... 115

Mixodectes................................. 35,101

crassiusculus............................ 92

pungens................................ 92

Mixodectidse...................... 34,92,93,95,101

Modernized mammals, invasion of........... 35

orders of................................. 33

Modernization, first stage of................. 35-42

second stage of........................... 57-69

third stage of............................ 84-90

Mollusca..........:.......................... 66

Monroe Creek, Nebr., fauna near.......... 112-114

Monroe Creek formation, homotaxis and

fauna of......................... 73

homotaxis of, figure showin g............. 72

Montana, fauna of............ 91-92,98-100,103-109

formations of, homotaxis of.............. 22

figure showing....................... 23,65

Monument Creek formation, description of... 61

Moropus......................... 72,74,111, 113,119

distans.................................. ios

elatus................................... 113

oregonensis.............................. 108

senex.................................... 108

sp....................................... 115

Mountain Region, deposits of, correlation of. 31-32 

erosion in................................ 21

homotaxis of, with plains deposits....... 22

figures showing...................... 23

mammalian life of....................... 20,22

 Tertiary history of....................... 19-25

Mountains, persistence of.................... 24

Multituberculata....................... 33,35,40,91

Muridae................. 63,66,105,107,110,116,119

Mustela................................. 80,90,118

americana............................... 90

minor................................... 116

ogygia................................... 114

parviloba................................ 114

Mustelidse............. 60,61,63,66,74,80,83,85,89,

90,103,105,107,110,112,114,116,118,120 

Mylagaulodon........................... 66,68,110

angulatus.................................. 107
INDEX. 131

Mylagaulidse.............. 77,78,80,81,114,116,119

Mylagaulus.............................. 78,81,119

Isevis.................................... 114

monodon................................ 116

paniensis.............................. 114,116

pristinus................................ 116

proxlmus................................ 116

sesquipedalis............................ 116

Mylodon........................... 82,83,85,87,89

sp....................................... 120

Mylohyus................................... 87,90

Myotis...................................... 90

N.

Nanohyus. See Ictops. '

Nanomeryx.....................:........... 103

caudatus................................ 98

Nebraska, fauna of........................ 103-109

formations in, homotaxis of.............. 65

figure showing....................... 65

Oligocene and Miocene in, map showing. 60 

Neohipparion......................... 79,80,83,119

 afflne.................................... 117

calamarium............................. ' 117

dolichops................................ 117

eurystylus............................... 117

gratum.................................. 117

ingenuum............................... 117

lenticularis.............................. 117

montezumse............................. 117

niobrarense.............................. 117

occidentale.............................. 117

 peninsulatum........................... 117

plicatile................................. 117

princeps-................................ 117

rectidens................................ 117

relictum................................. 117

rctrusum................................ 117

Sinclair!!................................. 117

speclosum............................... 117

whitneyi................................ 117

sp...................................'.... 120

Neoplagiaulax............................... 100

americanus...............'...-............ 91

molestus................................ 91

Neotoma.................................... 90

New Mexico, fauna of..................... 35,91-95

formation of, homotaxis of.............. 22

figure showing....................... 23,65

Nimravus............................... 68,75,110

confertus................................ 107

debilis................................... 107

gomphodus.............................. 107

sectator................................. 112

North Boulder Creek, Mont., fauna of..... 114-115

North Dakota, fauna of.................... 106-109

Notharctidse................... 46,52,92,95,98,100

Notharctus.............................. 46,47,100

afnnis................................... 95

anceps.................................. 95

cingulatus............................... 92

minutus................................. 93

nunienus................................ 92

palmer!................................. 92

rostratus................................ 95

tenebrosus.............................. 95

Page. 

Notharctus, tyrannus............:.......... 95

uintensis................................ 98

venticolus............................... 92

sp....................................... 95

Nothocyon.................... 68,73,74,75,110,118

annectens............................... 112

geismarianus............................ 106

gregorii.................................. 112

latidens................................. 106

lemur................................. 106,112

vulpinus................................ 112

Notostylops zone, mammals of.............. 33

Nototherium................................ 88

Nyctilestes................................... 101

Nyctitherium............................... 101

priscus.................................. 96

serotinus...............:.................. 96

velox.................................... 96

 0. 

Odocoileus......................... 86,87,88,89,90

Ogalalla formation, fauna of......... 79-81,115-118

homotaxis of............................ 79-81

Olbodotes................................... 101

Olfgobunis.......................... 66,75,110,118

crassivultus............................. 107

lepidus.................................. 112

sp.................................'...... 105

Oligocene, distribution of, plates showing.... 7,60

fauna of......................... 57-69,103-111

range of........................... 110-111

homotaxis of............................ 57-69

figures showing...................... 64,65

Oligocene, lower, fauna of.... 60-61,103-104,110-111

homotaxis of............................ 60-61

figure showing....................... 65

Oligocene, middle, fauna of.. 62-63,105-106,110-111 

homotaxis of............................ 62-63

figure showing....................... 65

Oligocene, upper, fauna of........... 63-69,10^-111

homotaxis of............................ 63-69

figure showing....................... 65

Oligocene-Eocene correlation, progress of..... 31

Oligocene-Pleistocene correlation, progress of. 31-32 

Oligotomus.................................. 102

Omomys.................................... 100

ameghini................................ 95

carter!.............................. .. 95

minutus................................ 93

pucillus................................. 95

Onychodectes............................... 102

rarus.................................... 92

tisonensis............................... 92

Oodectes................................ 46,52,100

herpestoides............................ 96

pugnax................................. 96

sp....................................... 96

Opisthotomus. See Phenacodus.

Oregon, fauna of.......................... 106-109

formations of, homotaxis of.............. 22,64

figure showing................... 23,65,67

Oreodon.................................... 67

afflnis................................... 104

bullatus............................... 104,106

coloradensis............................. 106

culbertsoni.............................. 106
132 INDEX.

Page. 

Oreodon, graeilis............................ 106

hybridus...................:............ 104

macrorhinus............................ 106

periculorum............................. 106

Oreodon zone, fauna of.............. 62-63,105-106

homotaxis of............................ 62

figure showing................' 23,62,64,65

Oreodontidae................................ 63,

64, 66; 68,69,73,74,75,78,80,81,82,100,

103, 104, 106,109,111,113,115,117,119

Oreodontinse................................ 57,61

Orohippus.............................. 49,52,102

agilis.................. I................. 98

 ballardi................................. 98

cinctus.................................. 98

major................................... 98

osbornianus............................. 98

procyoninus........................"..... 98

pumilus................................. 98

sylvaticus............................... 98

uintanus................................ 98

Orohippus zone, fauna of................. 50,95-98

homotaxis of......................... 22,50-53

figures showing.................... 23,51

Oromeryx................................... 103

plicatus................................. 100

Orotherium................................. 102

Osborn, H. F., on divergent evolution....... 42

on Great Plains deposition.............. 27

papers by......................... 10,11,12,16

Osborn, H. F., and Earle, Charles, paper by. 12 

Osborn, H.F., and Wortman, J. L.,paperby. 12 

Ovibos. ...................................... 87,89

OviniB...................................... 86,89

Oxyacodon.................................. 101

agapetillus.............................. 92

spiculatus............................... 92

Oxytena................................ 38,45,100

forcipata................................ 93

 huerfanensis ............................ 49,93

lupina................................... 93

morsitans............................... 93

sp....................................... 93

Oxysenidse. 37,40,45,46,48,52,54,57,93,96,98,100 

Oxysenodon................................. 100

dysclerus................................ 98

dysodus................................. 98

Oxyclsenidse....................... 33,34,35,91,101

Oxyclsenus.................................. 101

cuspidatus............................... 91

simplex................................. 91

Oxydactylus......................... 72,74,78,120

brachiceps............................... 114

longipes................................. 114

P.

Pachysena.................................. 45,101

gigantea................................. 93

intermedia.............................. 93

ossifraga. ............................... 93

Paciculus.................................... 110

insolitus................................. 107

lockingtonianus......................... 107

Paleearctomys............................... 118

macrorhinus............................ 116

montanus............................... 116

vetus.................................... 116

Page.

Palaeictops........................... 38,45,46,101

bicuspis................................. 93

Palseolagus.................................. 110

agapetillus............................... 108

brachyodon............................. 104

haydeni................................. 105

intermedius............................. 108

temnodon............................... 104

turgidus................................. 105

Palaeomeryx.............................. 77,78,80

americanus.............................. 118

antilopinus.............................. 115

borealis.................................. 115

teres..................................... 118

trilateralis............................... 118

sp..................................... 115,118

Palaeonictidse...................... 40,42,46,93,100

Palseonictis.................................. 100

occidentalis.............................. 93

Palseosinopa................................ 45,101

didelphoides............................. 93

veterrima.....:.......................... 93

Palseosyopinse sp............................. 98

Palseosyops.............................. 49,54,102

borealis............................... 44,45,51

fontinalis................................ 98

humilis.................................. 98

major.................................... 98

paludosus............................... 98

robustus.................................. 98

Panochthus................................. 83

Panolax..................................... 118

sanctsefidei.............................. 116

Pantolambda............................... 35,102

 bathmodon.............................. 92

cavirictus................................ 92

Pantolambda zone, fauna of........... 34-35,91-92

homotaxis of............................ 34

figure showing....................... 23

Pantolambdidse...................... 35,40,92,102

Pantolestes....................:............. 101

longicaudus............................. 96

sp....................................... 96

Pantolestidje................ 45,46,52,92,93,96,101

Paradaphsenus............................. 110

cuspigeras.............................. 106

transversus.............................. 106

Paradoxodon...................'............. 101

rutimeyeranus.......................... 91

Parahippus................. 70,72,74,75,78,80,119

avus.................................... 115

brevidens............................... 115

cognatus................................ 117

coloradensis............................. 115

crehidens.............. r ............... 113,115

nebrascensis............................. 113

pawnlensis.............................. 115

sp...................................... 113,115

Parahyus................................... 103

aberrans................................ 95

vagus.................................... 95

Paramylodon............................... 85,87

Paramys.............. 38,40,46,49,50,57,59,61,101

atwateri................................. 94

bicuspis................................. 94

copei.................................... 94
INDEX. 133

Page.

Paramys, delicatior......................... 97

delicatissimus........................... 07

delicatus................................ 97

excavatus................................ 94

leptodus................................ 97

major................................... 94

primsevus............................... 94

quadratus............................... 94

sciuroides............................... 99

uinteusis ............................... 99

sp....................................... 97,99

Paratylopus................................ 60,111

cameloides............................. 08,109

primsevus............................... 106

sternbergi.............................. 08,109

Parictis primaovus.......................... 107

Passalacodon................................ 101

 littoralis................................. 90

Patriofelis............................... 45,50,100

coloradensis............................. 90

ferox.................................... 50,96

tigrinus..........:...................... 93

ulta..................................... 50,90

sp....................................... 49

Pawnee Creek, Colo.,- fauna of............ 114-115

Poalo, A. C., on volcanic ash................ 24

Pccora...................................... 70,77

Pelycodus...................... 38,40,44,46,47,100

frugivorus............................... 92

jarrovii.................................. 92

tutus.................................... 92

sp...................................... 92,95

Pentacodou................................ 34,101

invcrsus................................. 92

Peraceras............................. 79,80,81,119

superciliosus............................ 116

Peraceras zone, fauna of................ 81,115-118

homotaxis of............................ 80

Peratherium................................ 110

alternans................................ 105

comstocki............................... 40,93

fngax................................... 105

huntii................................... 105

marginale............................... 105

pygmaeum............................... 105

scalare.................................. 105

titanelix................................. 103

tricuspis ................................ 105

Perchcerus.................................. Ill

lentus................................... 106

nan us................................... 109

osmonti................................. 109

platyops................................ 109

pristinus................................ 109

probus.................................. 100

robustus...'............................. 109

rostratus................................ 109

socialis.................................. 109

subsequans.............................. 109

trichaaius............................... 109

sp....................................... 109

Periptychidai........................ 33,35,92,102

Periptychus................................. 102

carinidens............................... 92

coarctatus............................... 92

rhabdodon.............................. 92

Page.

Perissodactyla.. 33,36,38,40,41,42,46,52,53,54,55,

56,57, 58,59, CO, 61,62,63,64,06,67, 68,74,75,

77,80,81,85,86,87,89,94-95,97-98,99,102,104,

105-106,108,111,113,114-115,116-117,118,120

Peromyscus............................ 90,110,119

loxodon.................................. 110

nematodon.............................. 107

parvus................................... 107

Peterson, 0. A., papers by.................. 16

Phenacoccelus........................... 73,74,119

typus.................................. 74,113

Phenacodontidaj...... 33,35,40,41,42,45,92,94,102

Phenacodus....................... 38,40,44,45,102

astutus.................................. 94

brachypternus.......................... 94

flagrans...:............................. 94

hemiconus.............................. 94

macropternus........................... 94

nunienus................................ 94

primaevus............................... 39,94

sulcatus................................. 94

wortmani............................... 49,94

sp....................................... 94

Philotrox.................................. 68,1.10

condoni................................. 107

Phlaocyon ................................. 118

leucosteus............................... 112

Pipestone Creek, Montana, fauna of....... 103-104

Pithecistes deccdens......................... 115

cmydinus............................... 115

incisivus. ............................... 115

simus................................... 115

Plagiaulacidte........................... 34,91,100

Plains Region, deposition in................. 20-28

deposits of, correlation of................ 31-32

erosion in............................... 21-22

homotaxis of, with mountain deposits... 22 

figures showing...................... 23

mammalian life of....................... 20,22

. Tertiary history of................ 19-23,20-28

Tertiary topography of.................. 28

Planus...................................... 78

Platygonus....................... 83,85,87, 88,89

bicalcaratus............................. 120

striatus.................................. 117

texanus................................. 120

Pleistocene, distribution of, plate showing... 7 

homotaxis and fauna of.................. 83-90

homotaxis of, figure showing............ 65

Pleistocene, lower, homotaxis and fauna of.. 83-86 

Pleistocene, middle, homotaxis and fauna of. 86-90 

Pleistocene-Oligocene correlation, progress of. 31-32 

Pleurolicus.................................. 110

diplophysus............................. 107

leptophrys.............................. 107

sulcifrons................................ 107

Pliauchenia ..................... 79, 80, 81, 83,120

humphroysiana......................... 117

minima................................. 117

spatula.................................. 120

vera..................................... 117

sp..................................... 117,120

Pliocene, distribution of, plate showing...... 7

gaps in.................................. 32

fauna of......................... 81-84,115-118

homotaxis of............................ 81-84

figure showing....................... 05
134 INDEX.

Page. 

Pliocene, lower, fauna of.................. 115-118

Pliocene, middle, fauna of............... 82-S3,120

homotaxis of............................ 82-83

Pliocene, upper, homotaxis and fauna of..... 83-84

Pliohippus.................................. 119

simplicidens............................. 120

supremus............................... 81

Pliolophus.................................. 49

Poatrephes.................................. 119

paludicola............................... 115

Poebrotherium............................. 64, 111

eximium................................ 106

labiatum................................ 106

wilsoni.................................. 106

sp....................................... 114

Polymastodon.............................. 100

attenuatus.............................. 91

flssidens................................. 91

selenodus............................... 91

taoensis................................. 91

Polymastodon zone, fauna of.......... 33-34,91-92

homotaxis of............................ 33

figure showing....................... 23

Pontien 6tage, homotaxis and fauna of...... 79-81

Port Kennedy cave, Pa., fauna of............ 87-88

Post-Cretaceous, homotaxis and fauna of.... 33-35

Potamotherium............................. 80

lacota ......................^............ 116

lycopotamicum......................... 114

robustum............................... 116

Potter Creek cave, California, fauna of....... 88-S9

Preptoceras................................. 89

Primates................................... 33,36,

38,40,52,56,57,59,88,92-93,95,98,100 

Proboscidea ............................. 33,69,76,

77,78,80,81,82,83,86,89,90,116,119,120 

Procamelus,.......................... 79,80,81,120

gracilis."................................. 117

lacustris.................................. 117

leptognathus............................ 117

madisonius.............................. 117

major................................... 117

minimus................................ 117

minor................................... 117

occidentalis .......................... '... 117

prehensilis.............................. 117

robustus...:.......................... 115,117

Procamelus zone, fauna of........... 79-80,115-118

homotaxis of............................ 64,79

Procynodictis vulpiceps..................... 99

Procyon..................................... 90

Procyonida;............ 46,64,80,89,90,112,116,118

Proglires.................................... 92

Promerycochcerus.... 30,68,69,70,73,74,75,111,119

carrikeri................................ 72,113

chelydra................................ 109

grandis.................................. 113

hatcheri................................. 113

hollandi................................. 113

leidyi................................... 109

macrostegus............................. 109

minor................................... 109

montanus............................... 115

obliquidens............................. 115

superbus............7................... 109

vantasselensis....................... 72,74,113

sp....................................... 113

Page.

Promerycochoarus zone, fauna of........... 68-69,

73-75,106,109,112-114 

homotaxis of................... 23,64,68,70-71

figures showing............. 64,65,67,70,72

Pronomotherium........................... 80,119

altiramis................................ 117

laticeps................................. 115

Proscalops.....................:............ 110

miocaenus .............................. 107

Prosciurus .................................. 110

ballovianus............................. 107

jeffersoni................................ 103

relictus.................................. 105

vetustus................................ 103

wortmani............................... 107

Prosthennops ........................... 80,81,119

crassigenls............................... 117

serus.................................... 117

Protagriochcerus............................ 103

annectens............................... 100

Protapirus................................. 68,111

obliquidens............................. 108

robustus................................ 108

simplex................................. 106

(Tapiravus) validus.....:.............. 20,108

Proterix..................................... 110

loomisi.................................. 105

Protoceras.............................. 64,74,111

celer.................................... 109

comptus................................ 109

nasutus................:................ 109

Protoceras zone, fauna of............... 63,106-109

homotaxis of............................ 63

figure showing................... 62,64,65

Protoceratidse............................... 120

Protochriacus. See Loxolophus.

Protogonodon............................... 102

pentacus................................ 92

stenognathus............................ 92

Protohippus...................... 79,80,81,83,119

castilli.................................. 117

cumminsii.............................. 120

fossulatus............................... 117

gracilis.................................. 117

interpolates............................. 117

minutus................................. 120

mirabilis................................ 117

pachyops................................ 117

parvulus................................ 117

perditus................................. 117

pernix.................................. 117

phlegon................................. 120

placidus................................. 117

profectus................................ 117

robustus................................ 117

simus................................... 117

spectans................................. 117

supremus............................... 117

Protohippus zone, fauna of..................

homotaxis of...........................

figure showing...................... 65,82

Protolabis ................................. 78,120

angustidens............................. 115

heterodontus............................ 115

longiceps................................ 115

montanus............................... 117

Protomeryx.................... 64,70,72,73,75,120
INDEX. 135

Page.

Protomeryx, cedrensls...................... 114

halll..................................... 114

sp....................................... 114

Protoptychus.............................. 57,101

hatcheri................................. 99

Protoreodon................................. 103

minor................................... 100

paradoxicus"............................. 100

parvus.................................. 100

pumilus,................................ 100

Protorohippus.............................. 102

Protoselene................................. 101

opisthacus.............................. 92

Protosorex.................................. 110

crassus.................................. 105

Protylopus.................................. 103

petersoni................................ 100

Provlverrinax............................... 101

Prunus...................................... 78

Pseudfelurus............................ 77,80,118

intrepidus............................. 114,116

Pseudolabis................................. ill

dakotensis.............................. 109

Pseudopterodon........................... 103,110

minutus................................. 103

Pseudotomus.............................. 57,101

hians.................................... 97

robustus................................ 97

superb us................................ 97

sp....................................... 97,99

Psittacotherium............................. 102

multifragum............................ 92

Ptilodus..................................... 100

mediaevus............................... 91

trouessartianus.......................... 91

Puerco formation, fauna of............ 33-34,91-92

homotaxis of............................ 22,33

figure showing...................... 23

Putorius............................. 80,89,90,118

nambianus.............................. 116

Q.

Quercus. 78

R.

Rangifer.................................... 86,87

Rattlesnake, -Oreg., fauna near............ 115-118

Rattlesnake formation, homotaxis and fauna

. of............................ 22,64,81

Reithrodontomys........................... 90

Republican River, deposits on.............. 80

fauna of................................ 115-118

Rhinocerotidae................................ 30,

57, 59, 61,62,63,64,66,68,73,74,76,78,80,

81,82,85,104,105,108, 111, 113,114,116,118

Rhinocerotoidea.................... 52,54,68,69,77

Rocky Mountains. See Mountain Region. 

Rodentia.................... 33,36,38,40,46,52,54,

55, 56, 57,58,59,61,63,64,66,68,73,74,75, 

77,78,80,81,85,89,90,94,97,99, 101, 103- 

104,105,107-108,112-113,114,116,118-119 

Rosebud formation, distribution of, plates

showing......................... 7,60

homotaxis and fauna of................. 70,75

homotaxis of, figures showing........ 23,64,70

Rosebud River, S. Dak., fauna near....... 112-114

Rupricaprinse .............................. 86,89

s- Page. 

Sage Creek, Mont., fauna of................ 98-100

Salix........................................ 78

Samwel cave, Cal., fauna of.................. 89

San Juan basin, N. Mex., fauna of........ 35,91-95

section of, figure showing................ 23

Sannoislen 6tage, homataxis and fauna of..... 60-61

Santa Fe, N. Mex., fauna near ............ 115-118

Sapindus.................................... 78

Sarcolemur.............................. 38,98,103

furcatus................................. 98

pygmseus............................... 98

Sarcothraustes..............................° 101

antiquus................................ 91

Sannatien Stage, homotaxis and fauna of..... 76-78

Scalops...................................... 90

Sciuravus......................... 44,46,59,61,101

buccatus................................ 94

depressus............................... 94

minimus................................. 97

nitidus.................................. 97

parvldens................................ 97

undans.................................. 97

sp....................................... 97

Sciuridffl.. 55,61,60 ,80,103,105,107, ] 10,114,116,118 

Sciurus..................................... 90,118

arctomyoides............................ 116

sp....................................... 114

Scott, W. B., papers by...................... 12,16

Scudder, S. H., papers by................... 16,18

Selenodonta................................. 52,57

Shufeldt, R. W., paper by................... 18

Sigmogomphius lecontei..................... 116

Sinclair, W. J., faunal lists by ............... 67

on Potter Creek cave.................... 88

on volcanic ash.................... ..... 25

papers by......................... 12,17,18,19

Sinopa.................................. 38,54,101

granger!................................. 96

hians.................................... 93

major.................................... 96

minor................................... 96

multicuspis i............................ 93

oplsthotoma...................... : ...... 93

pungens................................. 96

rapax.................................... 96

strenua.................................. 93

virerrina................................. 93

sp....................................... 93

Smilodectes................................. 100

gracilis................................... 95

Smilodontopsis.............................. 87,90

Solenodon................................... 61

Sorex........................................ 90

Soricidaj................................. 52,105,110

South Dakota, badlands of, bird's-eye view

of............................... 64

fauna of................ 1.............. 106-109

formations in, homotaxis of.............. 22

homotaxis of, figure showing......... 23,65

Oligocene and Miocene in, map showing. 60 

Sparnacien Stage, homotaxis and fauna of... 36-42 

Spermophilus................................ 90

Spilogale.................................... 89,90

Staked Plains, Texas, section of, figure showing.............................. 82

Stampien Stage, homotaxis and fauna of.... 60-63
136 INDEX.

Page. 

Stcgodon.................................... 82

Stehlin, IT. G., on European-American correlation............................ 39

Stenacodon.................................. 103

rarus.................................... 98

Stenomylus.................................. 120

gracilis.................................. 114

Steneoflber.......'.... 30,04,68,70,73,74,75,110,118

barbouri................................ 112

brachyceps.............................. 112

complexus.............................. 107

fossor................................... 112

gradatus... ............................ 107

hesperus................................ 107

montanus............................... 112

nebrascensis............................. 107

pansus.................................. 112

peninsulatus............................ 107

sciuroides............................... 112

simplicidens............................ 112

Stenomylus................................. 74

Sternberg, C. H., paper by.................. 17

Stibarus.................................... Ill

montanus............................... 104

obtusilobus ............................. 106

quadricuspis............................ 106

Stylemys..........:........................ 58

Stylinodon........................... 45,46,52,102

cylindrifer.............................. 94

mirus................................... 97

StylinodontidiB....... ....... 34,40,92,94,97,102

Subhyracodon copei. ........'.............. 105

occidentalis....... .................... 105

simplicidens... ........................ 105

sp...........:.... .'..................... 104

Suoidea.................................. 59,60,61

Swiftcurrent Creek, Canada, fauna of...... 103-104

Symborodon................................ Ill

acer..................................... 104

montanus................................ 104

torvus.... ............................ 104

Symbos..................................... 90

Syndyoceras....... ...................... 74,120

cooki.................................... 114

Synoplotherium............................ 101

lanius...... ............................ 96

Systemodon................................ 38,102

primaevus............................... 94

protapirinus. ........................ 94

semihians............................... 94

tapirinus............................... 94

T.

Tfeniodonta.'.... 33,34,35,40,45,46,52,92,94,97,102

Tagassuidae................... 113,115,117,119,120

Talpa....................................... 118

platybrachys............................ 114

Talpavidse.................................. 101

Talpavus................................... 101

nitidus.................................. 96

Talpidffi..... ....... 52,64,90,105,107,110,114,118

Tamias..................................... 90

Tapiravus............................... 78,80,119

rarus.................................... 116

validus.................................. 20

sp....................................... 115

Page. 

Tapiridse................................... 40,46,

52, 54, 57, 60, 61,62, 03,64,66,67,.68,78,80,86,

87, 90, 94,98,99,102, 106, 108, 111,115,116,119

Tapirus..................................... 87,89

Taxidea..................................... 89

Taxodium.................................. 78

Taxymys................................... 101

lucaris........................T......... '97

Teleoceras......................... 69,78,80,81,119

aurelianensis............................ 77

crassus................................... 116

fossiger.................................. 116

medicornutus........................... 114

sp....................................... 114

Teleoceratinae......................... 76,77,80,81

Telmalestes................................. 100

Telmatherium............................... 102

cultridens. .............................. 98

diploconum............................. 99

hyognathum............................ 98

megarhinum............................ 98

validum................................. 98

vallidens......................:......... 98

sp....................................... 99

Telmatolestes crassus........................ 95

sp....................................... 95

Temnocyon................................ 68,110

altigenis................................. 107

ferox.................................... 107

wallovianus............................. 107

Tephrocyon.................................. 118

rurestris................................. 114

Tertiary deposits, homotaxis of.............. 22

homotaxis of, figure showing............ 23

time scale for............................ 29-33

Tertiary history, outline of.................. 19-28

Testudinata................................. 57,66

Testudinida;................................. 58

Testudo............................... 66,72,74,83

brontops.......................:........ 58

Tetraclscnodon. See Euprotogonia. 

Texas, formations in, homotaxis of, figures

showing......................... 65,82

Than<$tien 6tage, homotaxis and fauna of.... 33-35

Thinocyon. ................................ 100

medius.................................. 96

velox.................................... 96

sp....................................... 96

Thomomys. ................................ 85

Thompson Creek, Mont., fauna of.......... 103-104

Ticholeptus................................ 78,119

bannackensis ........................... 115

brachymelis............................. 115

breviceps..........................:..... 115

zygomaticus ............................ 115

Ticholeptus zone, fauna of................ 114-115

homotaxis of............................ 76-77

figure showing...................... 23, 65

Tillodontia.................. 45,46,51,52,94,97,101

Tillomys.................................... 101

parvus................................. 97

senex................................... 97

Tillotherium.. ................... 49,50,52,97,101

fodiens.................................. 97

hyracoides ............................. 97

latidens................................. 97

sp.................. .................... 49,97
INDEX. 137

Page.

Tinoceras. See Uintatherlum.

Titanotheriidaj............................. 25,41,

43,46,48,52,54,57,60,01,95,98,99,102,104,111

Titanotherium.......................... 01,02,111

helocerus................................ 104

ingens................................... 104

prouti................................... 104

trigonoceras............................. 104

Titanotherium zone, fauna of........ GO-61,103-104

homotaxis of............................ 22, GO

figure showing....... ........ 23,02,64,65

Tomarctus.................................. 118

brevirostris............................. 114

Tongrien (Stage, homotaxis and fauna of..... GO-63

Torrejon formation, fauna of.......... 34-35,91-92

v homotaxis of......................... 22,34-35

figure showing...................... 23

Tortonien etage, homotaxis and fauna of..... 76-78

Tricentes.................................... 101

crassicollidens........................... 91

subtrigonus...................... ....... 91

Trigenicus.................................. Ill

mammiter..............'................. 104

socialis................................ . 104

Trigonias................................... Ill

osborni.................................. 104

sp....................................... 104

Trigonolestes............................ 38,48,103

brachystomus....... ................... 95

chacensis.............. ... .............. 95

metsiacus............................... 95

nuptus.................................. 95

secans...'................................ 95

sp.....................:................. ' 49

Trigonolestidje.............................: 95

Triisodon.................................. 35,101

gaudrianus.............................. 91

heilprinianus............................. 91

quivirensis.............................. 91

TriisodontidiB........................... 90,91,101

Triisodontina3.............................. 33,34

Trilophodon................................ 78,119

angustidens............................. 80

campester.............................. 81,116

euhypodon............................. 81,116

floridanus............................... 116

precursor............................... 116

productus............................... 116

shepardii................................ 120

Trionyx.......................'.............. 47

Triplopus................................... 102

amarorum............................... 97

cubitalis................................. 97

obliquidens.. ........................... 99

Tritemnodon............................ 44,45,100

agilis.................................... 96

white.................................. 93

TrogOSUS................................ 52,97,101

castoriclens............................... 97

minor.................................... 97

Twelvemile Creek, Kans., fauna of.......... 88

U. 

Uinta basin, deposits of...................... 54-57

fauna of................................ 98-100

Uinta formation, distribution of, map show- .

ing.............................. 37

homotaxis of, figures showing............ 23,56

Page. 

Uintacyon.................................. 93,100

bathygnathus........................... 96

edax..................................... 96

massetericus............................. 93

promicrodon............................. 93

scotti..................................... 98

vorax... ................................ 9G

sp....................................... 96

Uintatheriiclte................... 42,45,52,57,94,97

Uintatherium........................ 51,52,53,102

(Tinoceras) aflinis....................... 97

(Dinoceras) agreste...................... 97

(Tinoceras) anceps....................... 97

(Tinoceras) annectens................... 97

(Tinoceras) crassifrons................... 97

(Tinoceras) grandis...................... 97

(Tinoceras) hiaus........................ 97

(Tinoceras) ingens....................... 97

(Dinoceras) laticeps..................... 97

latif rons................................. 97

leidyanum............................... 97

(Tinoceras) longiceps.................... 97

(Dinoceras) lucare....................... 97

(Dinoceras) mirabile .................... 97

(Tinoceras) pugnax. .................... 97

robustum................................ 97

spierianum.............................. 97

(Tinoceras) stenops. .................... 97

(Tinoceras) vagans...................... 97'

sp....................................... 97

Uintatherium zone, fauna of..... 49-54,55-57,95-98

homotaxis of............. 22,42,49-50,53,54-55

figures showing................ 23,51,53,55

Ungulata............... 35, 40,42,46,52,54,57,61,84

United States, map of, showing fossil localities.............................. 7

Upper Brule Creek, S. Dak., fauna of..... 106-109

Urocyon.................................... 89,90

Ursidse............................. 04,85,86,89,90

Ursus................................. 87,88,89,90

Utah, fauna of............................. 98-100

formations of, homotaxis of............. 22

homotaxis of, figure showing........ 23

V. 

Vassacyon................................... :iOO

promicrodon............................ 03

Veatch, A. C., on volcanic ash............... 25

paper by................................ 12

Vespertilio.................................. 90

Viverravus................................. 40,100

dawkinsianus........................... 49,93

gracilis. .................................. 96

minutus................................. 96

sp...................................... 96

Viverridffi.............................'.:.... 64

Volcanic ash, distribution of.............. 22,24-25

"Volcanoes, prevalence of..................... 24

Vulpavus............................... 46,52,100

brevirostris.............................. 93

canavus................................. 93

palustris................................ 96

sp....................................... 93,96

Vulpes...................................... 89,90

W. 

Wasatch formation, distribution of, map

showing......................... 37
138 INDEX.

Page. 

Wasatch formation, fauna of.......... 36-42,92-95

homotaxis of............................ 36-42

figures showing.'.................. 23,38,39

Washakie Basin, Wyo., deposits of.......... 53-54

fauna of................................ 92-100

formations of, homotaxis of, figures showing.............................. 23,53

history of .............................. 53

Washakius.................................. 100

insignis................................. 95 

sp....................................... 95

Washtucna Lake, Wash., fauna of........... 89

Weeks, F. B., papers by.................... 9

White Buttes, N. Dak., fauna of.......... 106-109

White River group, fauna of.............. 103-111

homotaxis of............................ 60-61

figure showing...................... 23,62

Williston, S. W., papers by................. 18

Wind River Basin, Wyo., formations of,

homotaxis of, figure showing.... 23

Wind River formation, distribution of, map

showing......................... 37

fauna of........................... 43-48,92-95

homotaxis of............................ 43-48

Wortman, J. L., on Hueifano Basin......... 48

on volcanic ash.......................... 24

Page.

Wortman, J. L., on Wind River formation.. 47 

papers by............................ 11,13,17

Wortman, J. L., and Cope, E. D., paper by.. 17 

Wortman, J. L., and Osborn, H. F., papers

by.............................. 12,16

Wortmania................................. 102

otariidens............................... 92

Wyoming, fauna of................. 92-100,103-109

formations in, homotaxis of, figures showing.............................. 23,65

geologic map of.......................... 37

Oligocene and Miocene in, map showing. 60

X.

Xenotherium............................... 110

unicum................................. 103

Y. 

Ypr6sien, homotaxis and fauna of........... 36-50

Zeuglodon.................................. 20

Zeuglodon zone, mammals of................ 20

Zone, definition of........................... 7

Zones, mammalian, diagrammatic section

showing......................... 22

0
DEPARTMENT OF THE INTERIOR

UNITED STATES GEOLOGICAL SURVEY

GEORGE OTIS SMITH, DIRECTOR

361

GENOZOIC MAMMAL HORIZONS OF 

WESTERN NORTH AMERICA

BY

HENRY FAIRFIELD OSBORN

WITH

FAUNAL LISTS OF THE TERTIARY MAMMALIA 

OF THE WEST

WILLIAM D1LLER MATTHEW

WASHINGTON

GOVERNMENT PRINTING OFFICE

1909