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THE PERMO-CARBONIFEROUS RED

BEDS OF NORTH AMERICA AND

THEIR VERTEBRATE FAUNA

E. C. CASE

Professor of Historical Geology and Paleontology in the University oj Michigan

WASHINGTON, D. C.
Published by the Carnegie Institution of Washington

1915

CARNEGIE INSTITUTION OF WASHINGTON

Publication No. 207

Copies of this B«ok
were first i»uad

JUI\2 51915

9^3 3

PRESS OF J. B. LIPPINCOTT COMPANY
PHILADELPHIA

CONTENTS

Introduction 3

Chapter I. — Description of the Southern Portion of the Plains Province 5

The Texas Region 5

Location of the Beds 5

Stratigraphy of the Beds 6

Formation Names 7

The Wichita Formation 8

The Clear Fork Formation 28

The Double Mountain Formation 31

Occurrence of Fossil Vertebrates 32

Sections 33

Climatic Variations Recorded in the Permo-Carboniferous Beds of Texas 42

Evidence of Climatic Conditions in Wichita time 42

Evidence of Climatic Conditions in Clear Fork time 45

Summary of Climatic Conditions 49

Stratigraphy of the Beds in Oklahoma 51

Stratigraphy of the Beds in Kansas 56

Extension of the Red Beds beyond the Limits of Vertebrate Fossils in the Southern Portion of

the Plains Province 58

Evidence of a Barrier, or the Interruption of the Red Beds, in the Southwest 60

Chapter II. — Description of the Northern Portion of the Plains Province and the Eastern

Edge of the Rocky Mountains 62

Conclusions 70

Chapter III. — Description of the Basin Province 72

Chapter IV. — Description of the Permo-Carboniferous Beds in the Eastern Portion of

North America 77

Iowa 77

lUinois 77

Indiana 78

Ohio " 80

Pennsylvania and West Virginia 84

Prince Edward Island and Nova Scotia 86

Chapter V. — Geography of North America at the close of the Permo-Carboniferous.. 88

Chapter VI. — Age of the Red Beds 92

Limiting Horizons of the Vertebrate Fauna 93

Table showing the Permo-Carboniferous Fauna, as fur as known, with the Geographical and

Geological Distribution 96

Chapter VII. — Analysis of the Fauna 100

Food Habits as indicated by the Teeth 101

Food-supply 103

Terrestrial and Aquatic Adaptations 106

Table showing Aquatic and Terrestrial Adaptations 109

The Assumption of Armor and its Meaning 109

Over-specialized Forms in

Origin of the Fauna 117

Chapter VIII. — Description of Individu.vl Genera 124

Restoration of the Region and the Environment in which the Animals lived 147

Table showing the Forms in Texas and New Mexico which show Parallelism or Relationship in

Structure and Habits 149

Chapter IX. — Relation of North America to the Other Continents in Permo-Carbonifer-
ous Time 150

The Fate of the American Fauna I55

Appendi.x. — The Brier Creek Bone-bed and its Fauna 157

iii

THE PERMO-CARBONIFEROUS RED BEDS OF NORTH AMERICA
AND THEIR VERTEBRATE FAUNA

E. C. CASE

Professor of Historical Geology and Paleontology in the University of Michigan

INTRODUCTION.

The present paper is the fifth* in the series by the author on the verte-
brate fauna of the Permo-Carboniferous beds of North America, pubhshed
by the Carnegie Institution of Washington, including the vokmie on the
Permo-Carboniferous vertebrates of New Mexico by E. C. Case, and S. W.
WilHston of the University of Chicago. The object of this work is to
summarize, as far as possible, the information gained concerning the verte-
brate fauna; the influence of the environment in its history; its origin, evo-
lution and extinction or disappearance from North America; its range over
the continent, and its possible migrations. In order to make clear the con-
ditions under which the animals lived and developed it has been necessary
to introduce a somewhat extended description of the beds in which they
occur and to assemble all possible information relative to the character and
the sovirce of the sediments, the climatic conditions, and so forth. For the
amount of this material and the abundant quotations included the author
may perhaps be pardoned, as it has been his effort to include all possible
pertinent evidence in the knowledge that others may draw very different
conclusions from the same observations.

With the exact age of the beds the author has not troubled himself in
this publication; the sokition of this vexed question must require distinct
treatment and the best eft'orts of men far better qualified than he is at present
to evaluate the evidence of invertebrate fossils. Suffice it to say that from
the evidence furnished in detail in the body of this paper he is convinced
that the stage of evolution of the vertebrates, their stratigraphic position,
and the accompanying invertebrates indicate that the beds are of Permo-
Carboniferous age, and this conclusion is reached with a full knowledge
that the evidence from fossil plants is in favor of the Permian age of the
beds. Conflicting evidence of age from plant and animal fossils is no new
thing in stratigraphy, and we must wait until a more complete knowledge
can reconcile the different interpretations.

That our knowledge of the fauna is still incomplete is apparent to every
one who has paid any attention to the study or exploration of the beds,
but it has advanced so far that it is not probable that many entirely new
things will be found, and a summary of the known fauna and an account of

* I. Revision of the Pelycosauria of North America. Carnegie Inst, of Wash., Pub. 55, 1907.

2. Revision of the Cotylosauria of North America. Carnegie Inst, of Wash., Pub. 145, 191 1.

3. Revision of the Amphibia and Pisces of North America; with a Description of Permian Insects,
by E. H. Sellards; and a Discussion of the Fossil Fishes, by Louis Hussakof. Carnegie Inst, of Wash.,
Pub. 146, 191 1.

4. Permo-Carboniferous Vertebrates from New Mexico, by E. C. Case, S. W. Williston, and
M. G. Mehl. Carnegie Inst, of Wash., Pub. 181, 19 13.

4 INTRODUCTION.

the conditions under which they lived and developed may properly be
offered as a part of the series and for the same purpose — to fonn a basis for
future work.

From evidence furnished in the body of this work the author is convinced
that there were two large areas of Red Bed deposition in western North
America near the close of the Paleozoic. One may be referred to as the
Plains Province; it included the western portions of Texas, Oklahoma,
Kansas, Nebraska, and southwestern South Dakota and the portions of
Wyoming, Colorado, and New Mexico east of the Rocky Mountain Front
Ranges; that this area extended far to the north, even into Canada, there is
some evidence, but the limits of the northern portion can not yet be stated.
The other area, referred to as the Basin Province, can not be so clearly
outlined as the first, but from the combined evidence of vertebrate and
invertebrate fossils it is apparent that there was an area of Red Bed deposi-
tion west of the Rocky Mountain Front ranges, extending from the Colorado
Canyon through western New Mexico, western Colorado, Utah, and Wyo-
ming. Whether this area also extended farther to the north is not known.
The extent of these areas is shown on the map opposite page 88, plate 4.

It is not the intention of the author to maintain that deposition in the
two areas was contemporaneous; in fact, there is some reason to believe that
the western area received its deposits somewhat earlier than the eastern,
but this matter also remains to be decided.

Vertebrate fossils of Permo-Carboniferous age have been found in five
localities in North America: (i ) In an area in Texas, Oklahoma, and Kansas,
a portion of the Plains Province; (2) in north-central New Mexico, a portion
of the Basin Province; (3) in east-central Illinois; (4) in western Pennsyl-
vania; (5) in Prince Edward Island, Canada.

The author desires to repeat the thanks, expressed in previous publica-
tions, to the Carnegie Institution of Washington and its officers, for the
aid and encouragement which has enabled him to carry thus far a research,
which has involved no small amount of time and labor.

CHAPTER I.

DESCRIPTION OF THE SOUTHERN PORTION OF THE PLAINS PROVINCE.

THE TEXAS REGION.
LOCATION OF THE BEDS.''

The region most prolific in vertebrate fossils of Pemio-Carboniferous
age lies in north-central Texas, mostly in Wichita, Archer, Wilbarger, and
Baylor Counties, but the relatively abundant finds of fossils in this area are,
in part at least, due to the fortunate exposure of large areas of "bad lands"
devoid of vegetation and dissected by erosion. The same beds extend over
a much larger area, being exposed far to the south in Texas and to the north
in Oklahoma, with evidence that they extend north even to the Black Hills
and west to the Rocky Mountains. Gould has given the following outline
of the portion of the beds which have yi£lded vertebrate remains:''

"The mo.st northern exposure of the beds, so far as known to the writer, is
near Arlington, a few miles .south of Hutchinson, Reno County, Kansas. The
eastern border of the outcrop of the Red Beds in Kansas and Oklahoma is a crescent-
shaped line running southeast from near Hutchinson and east of Kingman, Kansas,
crossing the Kansas-Oklahoma line at Caldwell, then trending southeast near
Nardin, Tonkawa, and Red Rock, cutting diagonally across the strike of the
Pennsylvanian limestones and shale through the eastern part of Payne and Lincoln
Counties to the western part of the Creek and Seminole Nations. Here the line
swings to the southwest, and continues through the Chickasaw Nation to the
vicinity of Davis, Indian Territory, passes around the western end of the Arbuckle
Mountains, crossing Red River 35 miles west of Gainesville, Texas, and, as stated
by Adams, cuts diagonally across the strike of the Pennsylvanian limestones in
Archer, Young, and Throckmorton Counties, Texas."

Beyond Throckmorton County the Red Beds reckoned as Permo-
Carboniferous may be traced, as described by Cummins, generally south-
west through western Shackelford County and eastern Jones County, fol-
lowing the course of the Clear Fork of the Brazos River, thence south in
extreme western Callahan County to near its middle line ; thence southwest
across the southeast corner of Taylor County, and then generally south
through central Runnels County or a little east and south through Concho
County to beyond the Concho River. Here the line turns west beneath
the outcrop of the Cretaceous to the edge of the Llano Estacado, which it
follows north to the latitude of Amarillo ; north of Amarillo it appears in the
breaks of the Canadian near Plemons, in Hutchinson County, and possibly

' Compare map opposite page 6, plate I .

*• Gould, U. S. Geological Survey, Water Supply and Irrigation Paper No. 148, p. 37.

6 THE PERMO-CARBONIFEROUS RED BEDS OF

in Oldham County, Texas, and again in Beaver County, Oklahoma. From
here it appears at intervals from beneath the Tertiary, curving through
Clark, Comanche, Barber, Kingman, and Harper Counties, Kansas.

STRATIGRAPHY OF THE BEDS IN TEXAS.

The Permo- Carboniferous beds of Texas were divided by Cummins *
into three formations: the Double Mountain, the Clear Fork, and the
Wichita. Schuchert'' vmites these in the Brazos group, which is equivalent
to the Oklahoman of Keyes. These beds can be directly correlated with
certain beds in Oklahoma, as shown by the following from Gould :^

"From the best available information, it seems probable that the Wichita
beds are approximately the equivalent of those near Chandler, the Clear Fork
beds include about the same rocks as the Enid, Blaine, and Woodward formations,
and that the Double Mountain beds are practically the same as the Greer and the
Quartermaster formations."

With the ideas expressed by Gould in this quotation, the author is in
perfect accord, as the result of his work during several ycai-s in Texas and
Oklahoma, and especially from his study of the formations mentioned
during the summer of 191 2.

The Wichita and Clear Fork in Texas and the Enid in Oklahoma are
the only formations in which vertebrate fossils have been found. The
Wichita formation lies in an area between the east line described above
and a line running from the Red River southwest just east of HoUiday,
in Archer County, and south to the northwest corner of Young County,
where it crosses the west line and apparently continues a little west of south
to where it joins the edge of the Carboniferous. The line between the
Wichita and the Clear Fork is very difficult to determine at this point
(plate i). The western limit of the Clear Fork formation follows a line
approximately through or slightly west of Haskell, north to Seymoirr in
Baylor County, and north to the Red River, which it strikes just east of
the west line of Wilbarger County. This line is close to the one originally
drawn by Cummins.'^ The Double Mountain formation includes the western
portion of the Red Beds in Texas, between the western edge of the Clear
Fork and the eastern face of the Llano Estacado.

If, as believed by Gould and the author, the Enid, Blaine, and Woodward
formations in Oklahoma are the equivalent of the Clear Fork, the western
limit of the possible bone-bearing beds in that State runs northwest through
Caddo, Washita, Custer, Dewey, Woodward, and Harper Counties to the
Kansas line, as indicated in Gould's map.^ To this must be added, in the
opinion of the author, all the region marked by Gould as "Red Beds of

° Cummins, First Annual Report Geological Sur^'ey of Texas, 1889, p. 186.

*> Schuchert, Paleogeography of North America, Bull. Am. Geol. Soc, vol. 20, p. 558.

" Gould, U. S. Geological Survey, Water Supply and Irrigation Paper No. 154, p. 17.

•^ Cummins, 2d Annual Report, Geol. Sun'. Texas, map opposite p. 522.

'Gould, U. S. Geological Survey, Water Supply and Irrigation Paper No. 148.

LEGEND

Tertiary

Cretaceous

PC6fr.

QU8

Double
fountain

PCqg

irterm aster
Greer

PCcf

Clear Fork

PCwb

foodwar
Blaine

PC«

Wichita

Enid

Un identified

Carboniferous

Igneous and older
Paleozoic

The use of the same shade
in New Mexico and Kansas for
the unidentified beds does
not mean that they are of
the same age.

Compiled from various soui

Affosnt U'I.u/>. B.ii!imm, Md,.

NORTH AMERICA AND THEIR VERTEBRATE FAUNA. 7

uncertain relationship" surrounding the Wichita Mountains and occupying
all of Tillman County and parts of Comanche, Jackson, Greer, Kiowa, Caddo,
Washita, and Cotton Counties. Vertebrates have been found only in the
Enid formation, the portion of the Red Beds to the east, reckoned as equiva-
lent to the Wichita, not having yielded vertebrates, and the Blaine and
Woodward being, so far as known, equally barren. All the well-known
fossils from Oklahoma came from Grant, Kay, Noble, Garfield, and Logan
Counties, but a few have been found in Tillman and Comanche Counties.
Because the Texas beds have been most thoroughly explored and have
yielded the largest number of vertebrate fossils and are most completely
exposed by the erosion of the surface, they are here taken as a typical region
and will be described with considerable detail; other regions mentioned
will be compared with these beds as the standard.

FORMATION NAMES.

After reviewing the very considerable literature, it seems best to the
author to retain the names Wichita, Clear Fork, and Double Mountain,
proposed by Cummins. Gordon "" retains the name Wichita "for the for-
mation overlying the Cisco," with a revised description, and abandons the
name Albany. He describes the upper portion of the beds as "undifferen-
tiated Clear Fork and Double Mountain." To one who, in searching for
fossils, confines his attention to limited areas and passes slowly over the
beds intent on details, and is frequently occupied in an attempt to follow
a single layer, these beds present a hopeless tangle. The author has else-
where expressed his inability to distinguish a clear dividing-line between the
Wichita and the Clear Fork, but now believes that it may be recognized at
the first appearance of beds of limestone, although Gordon includes some of
these in the Wichita series. To the stratigrapher who passes over the country
more rapidly, scanning large areas and correlating, by resemblances based on
the average character, a more satisfactory separation may be possible.

Gordon's latest statement concerning the usage of names is as follows: ^

"Although much has been written concerning the beds between the Cisco
formation and the Triassic beds which underlie the 'Staked Plains,' much detailed
stratigraphic work remains to be done in this region before authoritative statements
can be made about the classification of these beds. On the evidence of fossil remains,
found chiefly in the lower beds in Baylor and Archer Counties, these strata are
now assigned by most geologists to the Permian. These rocks, as they exist in
the Wichita region, were subdivided by Cummins into the Wichita, Clear Fork,
and Double Mountain formations. The lowest formation, the Wichita, consisting
mainly of red clays and sandstones, is seemingly a near-shore or delta deposit,
and in it are found the remains of reptiles and plants of Permian age. Interstratified
with the clays and sandstones in the upper part of the formation are beds of lime-
stone containing marine invertebrates, of which a large proportion are Pennsyl-

* Gordon, Jour. Geol., vol. 19, p. 125, igii.

i" Gordon, U. S. Geological Survey, Water Supply and Irrigation Paper No. 317, pp. 21-22, 1913.

8 THE PERMO-CARBONIFEROUS RED BEDS OF

vanian types and few, if any, are considered characteristic of the Permian of Europe.
South of Baylor County the Clear Fork formation rests conformably upon marine
strata, consisting mainly of blue clays and shales, including considerable thicknesses
of Hmestone containing marine invertebrates. Neither reptilian nor plant remains
have been reported from these beds. The Pennsylvanian aspect of the fauna led
to the assignment of these beds, under the name 'Albany,' to the Pennsylvanian,
in the earlier reports, although they were recognized by some as being possibly of
Permian age.

"Subsequently Cummins asserted the equivalency of the Wichita and the
'Albany' formations and recommended the abandonment of the name 'Albany.'
Adams corroborated Cummins's conclusion as to the equivalency of the beds
included in the Wichita and 'Albany' formations, but recommended the abandon-
ment of all the names, Wichita, Clear Fork, and Double Mountain, as 'having no
stratigraphic significance.' In a paper by the writer and others, Cummins's con-
clusion as to the identity of the 'Albany ' with the Wichita and likewise the Permian
age of the formation is confirmed. It is shown also that the definition of the Wichita
as a formation is sufficiently established to warrant the retention of the name, and
that usage is followed in this report. It is to be noted, however, that some lime-
stones in Baylor County which Cummins regarded as belonging to the Clear Fork
are the equivalents of the upper beds of the 'Albany' and are here included in the
Wichita. The upper Permian beds included under the names Clear Fork and
Double Mountain in the Texas reports have had very little study, and no attempt
has been made to determine a definite line of division between the two formations.
In this report these beds are classed as undifi"erentiated Clear Fork and Double
Mountain."

THE WICHITA FORMATIO.V.

Cummins " originally described the Wichita as follows :

"The Wichita Beds are the lowest in the series, and are composed of sand-
stones, sandy shales, clays, and a peculiar conglomerate. The sandstones and
sandy shales are red, gray, and variegated, often containing large oval concretions,
ranging in size from one-quarter of an inch to several feet in diameter. The sand-
stones are often shaly in structure, while in other places they are massive. They
are often ripple-marked and at other places have a cross-bedded structure. The
concretions are very hard, and retain the peculiar structure of the sandstone in
which they occur. The clays are red and bluish. In the red clays are nodular
masses of clay, iron, and lime, which often take the form of geodes, filled with
tabular lime-spar in the center. The bluish clay is copper-bearing in many places.
The conglomerate is composed of rounded pieces of clay or clay ironstone, cemented
together l)y iron. Fossils occur in all these beds, which consist mostly of plants
and vertebrates, very few invertebrates being found. The largest number of the
vertebrates described by Professor E. D. Cope were taken from the Wichita Beds."

In the Second Annual Report of the Texas Geological Survey, page 400,
Cummins gives the following additional description of the Wichita Beds:

"The Wichita Beds, which are the lowest in the series, are easily distinguished
from the others by their peculiar characteristics. These beds are composed of
sandstones, clay beds, and a peculiar conglomerate. There are no limestones in

» First Annual Report, Geological Survey of Texas, 18S9, p. 186. Second Annual Report, Geological
Survey of Texas, 1890, p. 400.

NORTH AMERICA AND THEIR VERTEBRATE FAUNA. 9

it from top to bottom. The sandstones are of various colors. The clays are red
and bluish. In places the clay is copper-bearing, yet this is not entirely peculiar
to these beds, as the same thing occurs in the Clear Fork Beds. In the red clays
are iron concretions that exist in places in great abundance. The peculiar Permian
conglomerate which is found in this connection is composed of clay, or clay iron-
stone, in a ferruginous matrix."

QUATERNARY

PERM IAN

Recent
deposits

Seymour
gravel

Undifferentiated
Clear Fork and
Double Mountain

PENNSYLVA,NIAN

N N

V'^^v/.

Cisco
formation

Ca nyon
I imeatone

Strawn
formation

Fig. I. — Map showing Gordon's idea of the distribution of the Wichita, Clear Fork, and Double
Mountain formations in Te.xas. (After Gordon.)

Gordon,* in 191 1, gave an account of the same beds. He regards the
Wichita as extending much farther to the west than does Cummins or the
author, and includes much that was previously described as Clear Fork.
In discussing the Red Beds of Texas cast of a line drawn southwest from
near the mouth of the Pease River through Seymour to the northeastern

° Gordon, Jour. Geol., vol. xi.\, p. no, 191 1.

lO THE PERMO-CARBONIFEROUS RED BEDS OF

corner of Haskell County and thence sotithward, he says that it is the type
area of the Wichita formation:

"The western part of this area is characterized Ijy the occurrence of beds of
limestone and blue shale interbeddcd with red clays and sandstones, while the
eastern part is notal^le for the entire absence of limestones and the very limited
development of blue shale and clay. If a line be drawn from a point where the
Salt Fork of the Brazos crosses the boundary between Throckmorton and Young
Counties, a Httle east of north to the Red River, it will mark approximately the
boundary between the areas thus lithologically distinguished. * * *" (Page 112.)

"Rocks of the Wicliita Area. — East of Baylor County the rocks consist for the
most part of red concretionary clays, red sandstones and sandy shales with occa-
sional beds of blue shales, and Ijluish to grayish-white sandstones. Limestones are
conspicuously absent. Occasional impure nodular layers occur, however, which con-
tain considerable calcareous matter, but these do not constitute strata of limestone.
The sandstones are usually soft and distinctly cross-bedded. In some places they are
shaly, in others massive. Some layers are streaked and specked with grains of
black iron oxide, while others contain nodular masses and concretions of iron ore.

"The clays are mostly deep red or red mottled with bluish- white and drab
colors. The red clays contain an abundance of nodular concretions of irregular
shape, varying in size from that of a pea to masses 4 or 5 inches in diameter. They
consist of clay, iron, and lime, and are at times hollow or with the interior filled
with calcareous clay or lime carbonate. In some cases they are flattened and stand
in vertical position in the clays, suggesting their origin through the filling of fissures.
Occasionally a bed is met with consisting of rounded lumps of hardened clay
cemented together by ferruginous matter, representing what Cummins called a
'peculiar conglomerate.' This formation is believed to have had its origin in the
breaking-up of a bed of clay by running water or wave action.

"In places the bluish clays are copper-bearing. Efforts to mine these deposits
have not been profitable. The ore occurs in the fonn of small nodules in the clays
and also as a replacement of wood.

"In the sandstones occasional traces of plants occur, and sometimes remains
capable of identification are found. White reports Tcenioptcris from the sandstones
near Fulda. The stratification of the beds is very irregular. The sandstones,
shales, and clays grade into each other both vertically and horizontally. More-
over, there is a monotonous similarity in the sandstones and shales respectively
throughout the area, which, taken in connection with the absence of any persistent,
easily recognizable stratum, renders the stratigraphic correlation of the beds, except
within ver}' narrow limits, practically impossible. In eastern Clay and Montague
Counties, the beds, considered Cisco, show a greater development of sandstones,
some of which are conglomeratic. In the western part of the area, however, no
true conglomerates were observ^ed. * * *

"In the bluffs of the Wichita River, in the northwestern comer of Wichita
County, some beds of limestone, aggregating 4 feet in thickness, appear at the top
of the escaq^ment on the west side of Horseshoe Lake, and outcrops of these appear
at intervals along the boundary of Archer and Baylor Counties. The limestone
is earthy, very hard, dark blue where fresh, and weathers to dark brown or black.
It is underlain by 4 feet of blue clay. The remainder of the section to the foot of
the hill, about 100 feet, consists of red, concretion-bearing clay, with a limited
development of red and white shaly sandstone. From this point west the strati-
fication becomes more regular, consisting of the blue shales alternating with red,

NORTH AMERICA AND THEIR VERTEBRATE FAUNA. II

the red being predominant, with an occasional bed of darlv earthy limestone con-
taining usually an abundance of poorly preserved fossils.

"At the Bar-X Ranch on the Wichita River, in the northeast comer of Baylor
County, near the Old Military Crossing, several ledges of hard limestone appear
in the river bluffs, separated by varying thicknesses of blue shale, alternating with
red clay. The beds dip to the westward at inclinations estimated at 20 to 30 feet
per mile. Proceeding up the river from this point, limestones appear at intervals
in increasing development, the best outcrops occurring about 2 miles east of where
the Seymour- Vernon road crosses the river. Here an escarpment 90 feet in height
has the lower two-thirds composed of red and blue shales alternating with beds
of limestone. The middle of the section consists of red and concretionary clays
and sandstones. Some of the ledges of limestone are massive, but others are
thin-bedded and shaly, and separated by varying thicknesses of bluish clay. Locally
the thin-bedded limestones and their included shale grade horizontally into more
massivel}' bedded limestones. Fossils are not plentiful in this locality. The same
beds are exposed again northward in the banks of Beaver Creek. At Seymour
the limestones are well exposed in the banks of the river, where they are quarried
to some extent and furnish a stone that is well adapted to ordinary uses. The beds
are here transected by the Salt Fork of the Brazos, which flows in a relatively
narrow valley between steep bluffs 200 feet high, made up of interbedded red and
blue clays and limestones.

"The limestones of Baylor County area are generally fossiliferous. Owing
to the hardness of the rock, however, good specimens are difficult to obtain. Toward
the south there is an increase in the development of blue shale and limestone, while
the red clays and sands show a corresponding diminution. * * * "

"That the limestone series of Baylor County is the equivalent of the 'Albany'
formation of the southern area is fully established by both the stratigraphic and
the faunal evidence. The beds in the northern area, which include the limestones,
shales, and sandstones of Baylor County and the sandstones and shales of Archer
and Wichita Counties, constitute the Wichita formation" (p. 122).

In a later paper Gordon" gave the following account of the Wichita:

"The Wichita formation underlies practically the whole of Wichita, Baylor,
Throckmorton, and Shackelford Counties, a considerable part of Clay and Archer
Counties, and a small part of Young County. In Shackelford County it consists
of blue clays and shales with thick beds of limestones which, on account of their
greater resistance to erosion, crop out in a series of eastward-facing rock scarps.
The limestones, which constitute about a third of the formation, are blue, gray,
and yellowish, and for the most part massively bedded. They are generally hard,
semicrystalline to compact, but some beds are friable and chalky and others are
rough and earthy in texture. Thick beds and thin and shaly beds alternate. The
remainder of the formation consists of blue, gray, and black shales. The hmestones
contain an abundance of marine fossils, but well-preserved specimens are difficult
to obtain.

"Farther north there is a marked diminution in the proportion of calcareous
sediments, with a corresponding increa.se in argillaceous and arenaceous materials.
Some of the clay beds in Shackelford County are sandy, but toward the north the
sandy sediments become more and more prominent, many of the layers taking
on a red color. Red, white, and yellowish sandstone beds also make their appear-

" Gordon, U. S. Geological Survey, Water Supply and Irrigation Paper No. 317, 1913, p. 22.

12 THE PERMO-CARBONIFEROUS RED BEDS OF

ance and constitute a marked feature of the formation in Archer and eastern
Baylor Counties. The red sediments increase in amount northward until, in northern
Throckmorton County and beyond, the red color dominates in the formation.

"Throughout the northern area the clays are red or red mottled with bluish-
white and drab colors. The red clays contain an abundance of nodular concretions
of irregular shape, ranging from those the size of a pea to masses 4 or s inches in
diameter. Many are elongated or subspherical, and some are flattened and stand
vertically in the clay, suggesting their origin from the filling of fissures. They
consist of clay, iron, and lime, and some of them are either hollow or have their
interiors filled with calcareous clay. Here and there is a bed that consists of rounded
lumps of hardened clay cemented together by ferruginous matter, which Cummins
called a 'peculiar conglomerate.' It is suggested that this deposit may have
had its origin in the breaking up of a thin bed of clay soon after deposition, by the
action of running water or waves."

It will be noted that both Cummins and Gordon insist on the absence
of any limestone in the lower beds, and, though Gordon has shown that the
limestone of Baylor County can be traced southward into the upper "Albany,"
the author is inclined to believe that the limestone appearing in the eastern
part of Baylor County, called Beaverburk limestone by Udden,* marks so
definite a change in conditions that it should be considered as the first
member of a separate formation, and the author believes that Gordon's
map (fig. I, p. 9) places the western edge of the Wichita too far to the west
and that the line drawn by Cummins is more nearly accurate.

Transition of Limestones Into Red Beds.

On the east the Wichita beds shade through red shales and red limestones
into pure limestones. This fact has been only slowly accepted, but now
seems proven beyond doubt. The following pages contain the accounts of
this phenomenon collected from the various authors.

Adams'" was the first to call attention to the importance of this change
and reported his observations in several papers:

"In tracing the outcrops of the limestone formations of the Carboniferous of
Kansas, the writer observed that in going southward there is a gradual transition
in the character of the sediments to those which are more arenaceous, and that
there is a thickening of the shales and sandstones and a thinning and final dis-
appearance of some of the limestones."

Adams then gives full details of his tracing of the Fort Scott and Elk
Falls limestones from Kansas into Oklahoma, where the same series becomes
arenaceous and red.

"From what is known of the Permian limestones of Kansas, they will be found,
when followed southward, to diminish in thickness, and this change will be accom-
panied by a transition to more sandy beds. 'The Wellington Shales' are probably
represented southwestward by formations which are red. The approximate limit
of the red color is a line diagonal to the strike of the formations, and is found to

" Uddcn, Bull. University of Texas No. 246, 1912, p. 31.
*> Adams, Amer. Jour. Sci., vol. xii, 1901, p. 383.

NORTH AMERICA AND THEIR VERTEBRATE FAUNA.

correspond in a general way with the Une drawn by Mr. Cummins as separating
the Carboniferous and Permian."

"The distinctions which have been thus far outUned in Kansas do not hold
when the rocks are followed southwestward along their strike into the Indian

Fig. 2. — Map showing relation of Permo-Carboniferous limestones and Red
Beds in Kansas, Oklahoma, and Texas. (From Adams.)

Territory. Approximately along the Arkansas River, or a little south of that
stream, the interstratified limestones disappear from that section, and the forma-
tions are accordingly shales and sandstones. Moreover, the rocks in the Indian

» A full description of conditions, with maps, is given by Adams in Bulletin of the Geological Society
of America, vol. 4, p. 191, and U. S. Geological Survey Bull. 211, p. 71, 1903-

14 THE PERMO-CARBONIFEROUS RED BEDS OF

Territory gradually assume a red color in the higher portions of the section, the
line of transition to this color being diagonal to the strike. The Red Beds of Kansas
belong to this phase."

"In Indian Territory" " and Oklahoma the limestones thin out and disappear
from the section approximately along the Arkansas River. The striking feature
of the series south of the Arkansas is the transitions from sandstones and calcareous
shales with coal-beds, to red sandstones and shales. The line marking approxi-
mately the limit of the red color cuts diagonally across the stratification."

In another report,*" giving results of a reconnaisance made for the pvirpose
of reviewing the mapping done by Mr. Cummins of the Texas Survey,
Adams says:

"The limestones of the Albany division, although they thin out northward,
extend across the line drawn as the contact between the Carboniferous and the
Permian, and are represented in the Clear Fork and Wichita divisions."

In 1909 Beede ^ gave the following account of the transgression of the
red color into the limestones:

"In the region south of the western end of the Arbuckles the Red Beds lie
unconformably upon the tilted and eroded Pennsylvanian rocks. It appears that
the Albany- Wichita sea of northwest Texas transgressed over this region during
a time of slight depression, the waters covering the western end of the Arbuckle
Mountains, swinging eastward on their northern slope as far as the Seminole
country. According to Cummins, there is no unconformity in Texas between the
lighter sediments and the Red Beds, the transition between the Albany and the
Wichita being a gradual lateral one. The transgression of the Red Beds in the
Arbuckle Mountains msiy, then, be regarded as a northeastern or eastern encroach-
ment of the Wichita sea, or conditions of sedimentation, as all these beds may not
be marine. Whether this Arbuckle unconformity extends northeastward to the
easternmost limit of the Red Beds has not yet been determined, and indeed may
be very difficult to determine, where the unconformity would resolve itself to a
mere disconformity of the layers of shales, and perhaps accompanied by a greater
or less reworking of the lower deposits. Gould, who has been over this region
between the Arbuckles and the Arkansas River many times, states that he knows
of no unconformity. If no unconformity exists to the north of the Arbuckle Moun-
tains, it seems probable that the first Permian emergence began here and the depo-
sition of the Red Beds in the Seminole country is the first record of it, the later
sediments from the Arbuckles reaching farther north. Regarding the gradation
of the upper part of the Kansas section into the Red Beds in northern Oklahoma,
there can be no doubt whatever, and the same is probably true of the central
part of the State.

"The Arbuckle and Wichita Mountains are probably the source of much of the
red sediment, in which they are partially buried, and the former mountains are
directly responsible for the eastern extension of these beds into central Oklahoma.
The extent to which the lighter-colored sediments of Kansas and Texas are re-
placed by red sediments in Oklahoma and near it represents in a rough way the
limits of the influence of these mountains on the deposits of the time by the spread

"Adams, Lithologic Phases of the Pennsylvanian and Permian of Kansas, Indian Territory, and
Oklahoma (Abstract), Science, vol. 15, p. 545, 1902.

'' Adams, Abstract of paper read before Geological Society of Washington, Science, vol. 16, p. 1029, 1903
° Beede, Jour. Geol., vol. 17, p. 713, 1909.

NORTH AMERICA AND THEIR VERTEBRATE FAUNA.

of their sediments. By the time the deposition of the light-colored sediments had
ceased the conditions had become such that nearly all the sediments derived from
the land surrounding this basin were red.

"In the Oklahoman region the deposition of red sediments began, perhaps,
as low as the Howard or Topeka limestones, and perhaps as high as the Emporia
or Americus limestones. The deposits then seem to be uninterrupted until the
unconformity below the Dockum beds (Triassic) in the Texas Panhandle is reached.
Some of these beds appear to be of subaerial origin, as has been shown by Case,"
while others are certainly marine. Careful petrologic study will probably demon-
strate that much of the arenaceous material is wind-blown sediment, more or less
reworked by currents or waves as the regions were sub-
merged or flooded. That the sea covered the entire area
from Kansas to southern Texas and New Mexico at one time
may be questioned. If it did, the sediments contained were
of such a nature and abundance, or the waters so concen-
trated, as to preclude the free migration of a normal marine
fauna throughout the basin. That marine conditions pre-
vailed, at least locally, is demonstrated by the Whitehorse
and Dozier faunas.

"In Texas normal deposits were laid down in higher
horizons than in Oklahoma, and in Kansas there are reasons
for believing that the light-colored sediments were laid
down at an even later date than in Texas. These conditions
are illustrated by the subjoined table [fig. 3], showing a
vertical section of the Carboniferous and Permian rocks of
the three States."

In 191 2 Beede'' gave a second account of the same
phenomenon :

"In tracing the limestones and shales of the basal
Permian beds of Kansas southward into Oklahoma, the
relationship of the light-colored sediments to the red sand-
stones, red shales, and red limestones of Oklahoma is clearly
revealed. It is shown that some of the heavier ledges of
limestones first become sandy along their outcrops in patches
a few rods across. Farther south the sandstone areas in-
crease in size until the limestone appears only in local areas
in the sandstones, and is finally wanting. Traced farther
southward, the sandstones become deep red or brown, with
local areas of white. The decimation of the fauna sets in as
the limestones diminish, and the remains of life are not found far beyond the limits
of the hmestones. The shales become red very much farther north than do the
sandstones, and are frequently more deeply colored. Some of the lower limestones
become red before they change into sandstones. The sandstone ledges continue
for some distance southward as rather even, uniform beds, but farther on they are
found to thicken and thin in a somewhat systematic manner.

"Several ledges of sandstone frequently occur in a single section, and, where
one of these ledges is found thickened, the others are apt to be thicker than normal.
Likewise, they are all found to be thin over certain areas. The regions of thickening

RED-C

OlORED

ROCKS

Red

Wichita

/- ^

While

\ /

Albany

LlGHT-C

OLORED

ROCKS

TEXAS OKLAHOMA KANSAS

Fig. 3. — Chart showing re-
lation of the Permo-Carbon-
ifcrous rocks in Oklahoma,
Kansas, and Texas. (From
Beede.)

» Case, Bull. Amer. Mus., vol. 23, 1907,
!> Beede, Science, vol. 35, No. 896, 1912,

p. 659.
p. 348.

l6 THE PERMO-CARBONIFEROUS RED BEDS OF

and thinning were found to be parallel belts lying north and south at right angles
to the major drainage-lines. Two of these belts, together with an intervening
region about 8 miles across, were studied. The sandstones thicken at the expense
of the shales, sometimes eliminating them. In one instance a thin limestone was
traced southwest into one of these zones. A sandstone 20 feet or more beneath
the limestone thickens and rises above the limestone, and practically unites with
the sandstone some distance above it. The limestone seems to die out a few feet
from the sandstone, but farther west the latter shrinks to its normal thickness,
and the limestone is present in its proper position, with its usual characteristics."

As early as 1897, Cummins noted the same thing, Ijut did not grasp
its general character."

"By walking along the outcro]) every foot of the way we were enabled to note
the gradual change in the lithological character of the bed. ' ' [Following a prominent
bed of the Albany northeastward] "we found the Hmestone * * * gradually changed
in composition to a calcareous sandy clay, entirely destitute of fossils. * * *
North of the Brazos River, in the area heretofore designated as the Wichita division
in previous reports, the strata of the escarpment became more and more composed
of red clay, and the limestone beds less conspicuous. The limestone gradually
loses its limy nature."

Gordon records the same observations:''

"The red sandy shales and red sandstones in the Wichita Valley region were
replaced southward in large part by blue shales, light-colored sandstones, and
limestones. In some places the transition from a sandstone to a limestone was
plainly seen. * * * It is the conclusion of the author that the red beds of this
region are the near-.shore representatives of the Albany, and the decision as to their
age will rest upon that of the latter."

In 191 1, Gordon, "^ discussing the relation of the Albany to the Wichita,

says:

"When traced northward, the limestones of both the 'Albany' and the Cisco
formations diminish in thickness, while there is a corresponding increase in the
intervening beds of shale. In the case of the 'Albany,' the limestones show also
a change, becoming more earthy and irregular in their texture, and some of the beds
passing into gray indurated clays. The few limestones in the upper part of the
Cisco formation disappear entirely in the northern part of Young County. Along
with this change there is an increasing development of red clay, alternating with
blue. * * *

"At Fane Mountain, a low elevation in the southeastern corner of Throck-
morton County, is an outcropping of limestone characterized by an abundance of
Myaljiia permiana. These beds occur at intervals northward in eastern Throck-
morton County, and at Spring Creek in the northwestern comer of Young County
they outcrop in the bank of the river about a mile from the post-office. Here
the beds show a local gradation into sandstone, suggesting near-shore conditions
of sedimentation. * * *

' Cummins, The Texas Permian, Trans. Texas Acad. Sci., vol. 11, No. i, p. 95, 1897.

'' Gordon, The Red Beds of the Wichita-Brazos Region of North Texas (Abstract). Science, vol. 29,

1909. P- 75^-

"Gordon, The Wichita Formation of Northern Texas. Jour. Geol., vol. 19, 191 1, p. 118.

NORTH AMERICA AND THEIR VERTEBRATE FAUNA. 1 7

"Nowhere in the southern area, so far as observed, are there any indications
of unconformitj'. Notwithstanding the Hthological and faunal characteristics
which distinguish the 'Albany,' these beds appear perfectly conformable with the
Cisco below and the Clear Fork above, nor is there within the formation anj' indi-
cation of stratigrai3hic discordance. The change in the Hthological character of
the beds toward the north is evidently the result of differences in the conditions
of sedimentation. The character of this ])art of the formation suggests very strongly
its origin on a coastal i)lain, or river delta, to the south and west of which lay the
sea, in which were deposited the marine 'Albany' sediments. The interrelations
of the two kinds of sediments suggest oscillation of the shore-line upon a relatively
wide coastal plain. These changes may be explained as the result of oscillations
of the land surface, or, possibly better, by the slow, but intermittent, sinking of
the coastal plain."

In a later paper Gordon ■* further discussed this point :

"A feature of importance in the Cisco formation, and one which it shares
with the next succeeding formation, is the series of changes observed as the forma-
tion is traced northward along the strike. These changes relate both to variation
in Hthologic character and to thickness of beds. In the Colorado Valley, inter-
stratified with the sandstones, clays, and conglomerates, are six or more beds of
limestone, each from 5 to 25 feet thick and all aggregating a thickness of 100 to
150 feet. In the southern part of the Brazos Valley the calcareous divisions are
only about half as thick as they are farther south, and the clays show a correspond-
ing increase in thickness. In Young County the calcareous material diminishes
northward at an increased rate until, at the northern boundary of the county,
the limestones have practically disap]:;eared, and beyond that point they are repre-
sented apparently by irregular nodular masses of earth}' limestone in a matrix of
clay. With the thinning out of the limestones the shales and sandstones increase
in thickness. In Stephens County and farther south the shales are prevailingly
blue and the sandstones gray. Red Beds are dispersed sparingly through the for-
mation. The blues gradually give place to reds until in the vicinity of Red River
the red color dominates. In this part of the region the rocks consist, for the most
part, of red sandstones, clays, and sandy shales, with a few beds of blue shale and
bluish to grayish-white sandstones. Limestones are conspicuously absent. * * *

"Beds of red clay make their appearance south of Young County, but they
increase notably to the north, especially in the upper part of the formation, along
with the diminution of the limestones, and they constitute the dominant feature
of the formation in eastern Clay and western Montague Counties."

Gould,'' in discussing the relation of the limestones of Kansas and
eastern Oklahoma, describes the change to the red sandstones and shales
in several papers.

"While the flint hills in Kansas consist almost entirely of limestones and shales,
still on the southern line of the State sandstones have already begun to appear.
To the south, these conditions obtain more and more until the limestone is entirely
replaced by sandstone. * * * South of the State line, the sandstones from the
east and the Red Beds of the west begin to approach each other, while the limestone

' Gordon, U. S. Geological Survey, Water Supply and Irrigation Paper No. 317, pp. 18-20, 1913.
^ Gould, Notes on the Geology of the Seminole, Creek, Cherokee, and Osage Nations, Amer. Jour. Sci.
vol. II, p. 185, 1901.

l8 THE PERMO-CARBONIFEROUS RED BEDS OF

ledges become thinner and thinner, and the flint less pronounced. In general * * *,
it may be observed that in going eastward from the Red Beds toward the Carbon-
iferous the sandstones and shales, which have been of a deep, brick-red color,
become more and more brownish and grayish, and finally lose entirely their char-
acteristic hue and take on that of the older formations. The lithology changes

also. * * *"

"The Marion and Welhngton formations" narrow rapidly in northern Okla-
homa, and their place is taken by the Red Beds. Perhaps it is more correct to
state that the color of the shales appears to change to the south, and to become red,
while at the same time more of the red sandstone comes in, all tending to change
the formation in lithological appearance to that of typical Red Beds.

"A section of the Twin Hills, 7 miles east of Ingalls, eastern Oklahoma, shows
three ledges of limestone, the thickest of which is not more than 4 feet, while all
the rest of the rocks are either red shales or sandstones. Above these Hmestones
are ledges of grayish or red sandstones, which thicken to the south and west, and,
in the region between Stillwater and Orlando, assume the red tint so common in
the Red Beds. * * * The line of separation between the rocks of these two ages
(Carboniferous and Permian) must finally be drawn far out in the Red Beds."

"* * * These formations'" [Marion and Wellington] narrow rapidly in northern
Oklahoma, and their place is taken by the Red Beds. Perhaps it is more correct
to state that the color of the shales changes to the south, becoming red, while at
the same time more of the red sandstone comes in, so that finally the formation
changes to typical Red Beds. On the State line, the distance from the Winfield
formation, the upper conspicuous limestone member, to the eastern outcrop of
the Red Beds is perhaps 30 miles; on the southern line of Kay County, Oklahoma,
it is not more than 1 5 miles, while farther south the Hne of separation can not be
determined, for the reason that the hmestone disappears, and its place is taken by
red shales and sandstones. In southern Kansas there are three distinct kinds of
Permian rocks: first, the heavy limestones in eastern Cowley County and along
Walnut River; second, the bluish and gray clays and shales of the Marion and
Wellington formations from Walnut River to western Sumner County ; and, third,
the typical Red Beds, consisting of red sandstones and clays extending from this
point nearly to the west line of the State. In eastern Oklahoma, on the other
hand, only Red Beds appear. Thus it is seen that the Red Beds extend farther
east in Oklahoma than in Kansas, and that the eastern limit of the Red Beds
does not coincide with the Hne of separation between the Pennsylvanian and the
Permian. In other words, the red color of the rocks, which has been thought
characteristic of only the Permian of the region, in fact transgresses far into the
region of the Pennsylvanian rocks. This means, of course, that the line of separa-
tion between the rocks of these two epochs must finally be drawn far out in the
Red Beds, and this the writer has attempted to do."

In 1914 Beede'= gave a detailed account of the lithologic and color
changes in Oklahoma largely corroborative and supplementary to his former
account.

"Gould, General Geology of Oklahoma, Second Biannual Report Oklahoma Geological and Natural
History Survey, p. 27, 1902.

>> Gould, Geology and Water Resources of Oklahoma, U. S. Geological Survey, Water Supply and
Irrigation Paper No. 148, p. 35, 1905.

"Beede, Oklahoma Geological Survey, Bulletin 21, 1914. p. 25.

NORTH AMERICA AND THEIR VERTEBRATE FAUNA.

Udden,* in 1912, presented a very full account of the rocks and other
deposits of Archer and Wichita Counties, most of which would be included
in the Wichita formation as it is conceived by the author:

"It is believed that these sections (see p. 34) represent different parts of a
general section some 300 feet thick. They are known to include successive strata
measuring about 225 feet, and constituting the uppermost beds exposed in the
field examined. We shall regard these sections first as a group representative of
a single formation. They all occur within the areal limits of what has come to be
known as the Wichita formation." ^

"The thickest section measures only 130 feet in all, and most of them fall
short of 50 feet. The total number of feet of rock described is only a few feet
more than 1,000. Some items are known to be repeated descriptions of the same
strata, in places where the sections are not very far apart, and many more of them
must include beds that are synchronous and were made at the same time.

From these sections we may obtain a fairly close estimate of the gross nature
of the formation. As seen in the exposures, it consists of shales, sandstones, con-
glomerates and limestones, named in order of their rank as to bulk. Seventy-nine
per cent of the total thickness described in the section consists of shale, 20 per
cent of sandstone, and less than i per cent each of conglomerate and limestone.
There are also gradations between all of these groups. It is believed that the
percentage of sandstones determined in this manner is higher than the actual
percentage of sandstone in the formation, as this rock stands weathering better
than the shales, and is hence more frequently preserved in the outcrops. But
the difference between the actual and apparent ratios of sandstone and shale can
not be very great. In section 25 [section 34 of this paper] above, where there is a
total of 124 feet of shale and sand, the percentage of shale is 83, and that of sand-
stone 17. The relative quantities of different rocks are shown in the following
table, in which the several rocks described and measured in the sections are classi-
fied, summed up, and reduced to percentages :

' " Table showing total thicknesses in feel and percentages of different kinds
of rocks described in sections seen in Wichita and Clay Counties.

Total feet.

Per cent of
total feet.

Shale

789
(580)

(113)
(96)

201
8
6

79
(58)
(II)
(10)
20
•5
■5

Red shale

Red and blue shale . .

Sandstone

Conglomerate

Limestone

Total

1,004

100

AVERAGE THICKNESS OF DIFFERENT BEDS.

"The beds described vary in thickness from less than i foot to 60 feet. Not
one of the conglomerates or limestones is more than 3 feet thick, and only 11 in-
stances were noted of sandstones exceeding 5 feet. Of these only 3 were more than

» Udden, Bull. University of Texas No. 246, 1912.

*> W. F. Cummins, First Annual Report Geological Survey Texas, 1889, p. 186; C. H. Gordon, George
H. Girty, and David White, Jour. Geol., vol. 19, igii, pp. 110-134, and others.

THE PERMO-CARBONIFEROUS RED BEDS OF

lo feet, while none exceeded 15 feet. The shales are more heavily bedded. In 43
instances these measure more than 5 feet thick, while there were only 23 beds of
shale measuring less than 5 feet. These relations are more fully presented in the
following table:

" Table shoivirig frequency of different thicknesses of strata as described in the sections noted in

Clay and Wichita Counties.

Measured thickness in feet.

1-5

6~I0

11-15

16-20

21-25

26-30 41-45

61-65

Number of sandstones.

Number of conglomerates

Number of all kinds of rocks .

14 1 9

THE WICHITA SHALES.

"From the observations made in the field it appears that about 73 per cent of
the bulk of the shales of the exposed Wichita formation consists of greenish, bluish,
or light gray shale, and about 13 per cent consists of alternating layers of red and
gray shale, or blotched red and gray shale." The greater part of this shale is fine
in texture, containing very few quartz grains which measure more than one-sixteenth
of a millimeter in diameter.
The Gray and Blue Shale.

"The bluish-gray or greenish-gray shales are usually found under the sandstones
and limestones. We also find, in similar situations, streaky or blotched mixtures of
gray and red shale.

"The gray or bluish-gray shale frequently contains minute fragments of chitinous,
brown, translucent fragments of scales of fishes, which sometimes also are found entire.
In some of the blue shales, these fragments are found in large numbers. * * *

"Where the gray shales are dark they frequently contain minute imbedded
shreds of vegetation, and even entire leaves. Bituminous matter is also frequently
present in quantity sufficient to produce a bituminous odor when a fragment of
the shale is heated in a closed tube. When large concretions occur in this shale,
they are usually flat and consist of Hme or of carbonate of iron. Small crystals of
marcasite also occur. These, as well as the concretions, have often been oxidized,
the concretions being more or less completely changed to limonite, and the marcasite
appearing as rusty specks in the shale.
The Red Shale.

"The red shale constitutes the greater part of the exposed Wichita formation.
The red color is due to the presence of hematitic material. The red tints vary from
yellow to light red, dark red, purple, brown, and dark brown. Some of the red
shales are highly ferruginous, containing no less than 10 per cent of oxide of iron.
These are generally very fine in texture. The usual percentage of ferruginous
material is very much less, probably less than 5 per cent.

"In its texture the red shale is very much like the blue shale, and varies from
very fine material to sandy shale. A small part of the shale consists of quartz
grains measuring more than one-sixteenth of a millimeter in diameter. With this
ingredient there are usually some scales of mica. The hematitic material is present
in a state of extremely fine subdivision.

' The excess of green and blue shale noted by Udden over that reported by other authors is in part
due to the fact that he includes some of the Clear Fork in his Wichita and in part due to the local character
of the beds in the area in which he worked. Compare his statement under "Red Shale." — E. C. Case.

NORTH AMERICA AND THEIR VERTEBRATE FAUNA. 21

"The red shale is in many cases somewhat obscurely stratified, showing hardly
any lamination or other perceptible structure in beds several feet thick. In places
where it is mingled with gray or white layers, the stratification is very trenchantly
shown. In some such exposures contemporaneous unconformities are to be seen,
where a series of overlying laminated shales bend in conformity to the surface of a
local excavation in an underlying horizontally stratified clay or shale.
Concretions in the Shale.

"The red shale usually contains numerous concretions of material which once
no doubt was disseminated generally through the body of the shale. Eroded slopes
of this shale are frequently closely strewn with these concretions, which remain
intact on the surface after the rains have washed away the readily disintegrated
matrix in which the concretions were originally formed and imbedded. The com-
mon form of the concretions is an irregular spheroid, and the usual sizes are from
half an inch to 4 or 5 inches in diameter. They usually have a very irregular
exterior surface, which in some may be described as irregularly botryoidal, as
mammillated, pitted, furrowed, ridged, or which may be so entirely irregular as to
defy any general description. vSuch are the greater number. Only in rare cases
are some found with a smooth outer surface. In some cases they approach a cylin-
dric form, and it appears that such concretions have started to form either in some
tubular cavities in the shale, or around some narrow cylindrical bodies buried in
the shale, for some such concretions still show traces of a centrally located tubular
cavity. Some concretions of this form were noted at a horizon in a red shale, which
at another place, a mile distant, contains sandy layers with fossil leaves, and the
suggestion prompts itself that these concretions have grown around roots or small
branches of plants originally imbedded in the shale. Some of these concretions
were seen to have had an inclined position in the strata. Another instance of
cylindric forms was noted in some sandy shale. In this case concretionary lime had
cemented the fine sand along a line vertical or slightlj' inclined to the stratification
planes, causing a cylindric or rather cone-shaped form to weather out from the shale.

"In some places the concretionary material has been deposited along certain
structures in the shale, as along sandy layers, or in joints which have developed
in the clay. When these joints have opened up in the process the concretionary
material takes the form of irregular fissure veins. Some calcareous veins of this
kind were noted in a shale bank a short distance northeast of Electra. A system
of intersecting joints, closely set, seem to have been developed in the clayey matrix
next to some of the large concretions, with the result that the calcareous filling in
these fissures extends out and away from the concretions, and forms an irregular
network of ridges on their surfaces. The mammillated and irregularly botryoidal
surface on some concretions is clearly the result of an interruption of the concretion-
ary growth, and of a later resumption of the same, which has been more localized.

"Internally the concretions in some cases show an irregular concentric structure,
and in one locality this was seen to consist of numerous smooth and even concentric
layers. More frequently they have radiating internal fissures which are filled by some-
what pure carbonate of lime, either in the form of crystalline calcite, of amorphous cal-
cite, or of a white powder of the same mineral . In other instances the internal structure
shows that some concretions are aggregations of many concretions of the smaller and
greatly variable sizes."

SANDSTONES.

"The sandstones of the Wichita formation constitute something less than 20
per cent of the whole in the exposures. They are mostly light gray in color, though
some are red, dark gray, or mottled.

THE PERMO-C.\RBONIFEROUS RED BEDS OF

"The development of the sandstones is irregular. They frequently change in
thickness, and may run out in a few hundred feet. They can seldom be traced in
continuous outcrop for more than a mile or two."
Texture.

"The sandstones are fine in texture, about 85 per cent of the weight of the
sand consisting of grains measuring from one-fourth to one-sixteenth of a millimeter
in diameter. Grains measuring more than one-fourth of a millimeter are scarce,
constituting only a small fraction of i per cent, in case any such grains are present
at all. Compared with other sands the Wichita sands are well sorted. They contain
very little material in which the grains measure less than one-sixteenth millimeter
in diameter. In this respect the Wichita sand is a true beach sand. To plainly
present these characteristics, a few mechanical analyses have been made, as shown
[below]. Analyses of the three Cisco sands are also introduced for comparison.

" Table shmving the mechanical composition of sandstones in the Wichita and the Cisco formations, in
percentages of weights of different grades of coarseness.

Diameter
of sand grains.

Cisco sands.

Wicliita sands.

I
20

43
26
10

tr.
8

69
9
4

tr.
tr.
84
10
6

tr.

1
81 70

tr.

57
29

43
38
19

tr.

28
48

24
tr.

tr.

57
28

tr.

% to Vt mm

V, to '/» mm

Vi to '4 ram

! IS to }ii mm

M2 to \, mm

1 1

13
8

A, South of Bellevue, Clay Count}'.

B, 3 miles east of Henrietta, Clay County.

C, Near Bellevue, Clay County.

D, Averages for Clay County.

E, Finder's Butte, 3 miles WNW. of

Holliday, Wichita County.

F, 3 miles west of Burkburnett, Wichita County.

0, Wichita Falls, Wichita County.

H, Butte on Palo Pinto School lands, Wichita County.

1, Tenth Cavalry Creek, Wichita County.
J, Electra red sand, Wichita County.

K, Average for Wichita County.

"The Wichita sands do not appear to be greatly worn, for even the coarser
grains are not well rounded. The surface of the sand grains very generally sliows
the effect of etching, being roughened or verv- irregularly pitted. This etching has
no doubt been effected by the solvent action of percolating ground water, which at
times probably has contained a comparatively large amoimt of alkalies in solution.
Characteristic Bedding in Sandsloucs.

"We have already noted that in their mechanical composition the Wichita
sandstones resemble beach sands, or near-shore sands, being well sorted. Physical
conditions of this kind are also indicated by other features of sedimentation. In
a few places the sandstone is a freestone, showing no preferential planes of cleavage
in any direction, and no bedding planes of any kind. But no strata of this kind
were noted exceeding 4 or 5 feet, nor did these appear to run far horizontally. It
suggests itself that such beds may once have been small wind drifts on the sandy
beaches, which happened to remain undestroyed, and to be buried under other
sands later brought by the coastal currents of the sea. Usually these sandstones
are distinctly stratified and are built in layers from a few inches to a foot or two
thick. Sometimes these layers show a fine horizontal lamination. There extend
smooth and straight division planes horizontally in the stone for many yards in
both dimensions of a horizontal plane. These divide the layers into thin laminae
from a sixteenth to a fourth of an inch thick. Even the thinnest of these laminae
seem to be traceable for many feet, and with favorable weathering slabs of such
rock may be split into plates not much thicker than a card-board, and as large as

NORTH AMERICA AND THEIR VERTEBRATE FAUNA. 23

a man's hand. In places these thin layers are marked by parallel varicose lines,
which seem to be wave-marks. In other places the division planes are themselves
thrown into very shallow, hardly perceptible folds, a few inches wide. These are
evidently incipient ripple-marks, for in some places they are found in association
with well-developed ripples. Ripple-marks are not very common features in the
bedding of these sands, and were noted at only a few places in this field.
Cross-bedding.

"The most frequent and conspicuous bedding characteristic of the Wichita
sandstones is cross-bedding or so-called false bedding. There are few outcrops of
sandstone where this form of stratification may not be found. The thinness of the
beds in this field prevents it from being developed on a grand scale. The thickest
single cross-bedded strata noted here are not more than 3 feet in thickness, and the
common thickness of single layers of this kind is less than a foot. On the other
hand, the development of small, fine work in cross-bedding seems to have reached a
culmination in these sands. Layers no more than a half-inch thick are often seen
to be quite regularly cross-bedded. It is evident that this cross-bedding is the
result of currents in the direction of the slant of the false bedding. These slants
are, in each case, the indices of local currents which produce them. In each out-
crop there may often be found several directions of these slants, but usually one
or two directions prevail. For the purpose of securing some information on the
general direction of the transporting currents which brought this sand, some obser-
vations were made on the direction of the slants in the false bedding of the thickest
strata. Each slant noted was referred to one of eight directions of the compass,
the four cardinal points and the four intermediate jioints. In all, 125 observations
were taken, 30 in Clay County and 95 in Wichita County."
Significance of Cross-bedding.

"The greater frequency of the westwardly directed depositing currents is clearly
shown by these observations. It would, nevertheless, be hasty to conclude that
the resultant direction is a true index of the direction from the land to the sea at
the time of the making of those beds. The general direction of transportation in
sand bars and sand beaches is not always from the land seaward. It may as well
be parallel with the coast-line. But it can not be largely from the sea landward.
All that we may safely infer from these observations is that the land at that time
was not to the west with the sea to the east. If the ancient shore-line extended in
a north and south direction, there must have been an open sea to the west. But
if the course of the shore-line was from the east to the west, the land may, so far
as these observations are concerned, have been somewhere in a northeast or an
east direction. The northward trend of the resultants renders it unlikely that the
shore-Hne extended in an east-west course, as this would require a landward trans-
portation of the sand. The land, hence, probably lay to the east, southeast, or
northeast, all evidence considered, with an open sea to the west, northwest, or to
the southwest. ^

Small Contemporaneous Faulting.

"Some thin and fine-grained layers of sandstone which are interbedded in the
red shales in the breaks of Bluff Creek, southwest of Electra, exhibit a peculiar

" The average direction of tlie inclination was 2° north of west. — E. C. C.

•* Udden's conclusions do not necessarily follow from his observations. It is very probable that the
sandstones with their observed dips were deposited in pools on the surface of the subaerial portion of the
delta plain and not upon a sea-shore. Other evidence clearly shows that there was a sea to the east and land
to the west and north. — E. C. C.

24 THE PERMO-CARBONIFEROUS RED BEDS OF

small faulting, which is believed to have taken place almost immediately after the
sand was laid down, and before it had been consolidated to any degree. Layers
of sandstone i to 4 inches thick are faulted along gently but somewhat irregularly
curving lines, which run roughly parallel from a half-inch to several inches apart.
The displacement at each little fault is from zero to a half-inch. We have seen
such faulting in rapidly accumulated soft mud settling on sloping banks under its
own weight, and we have no doubt but that these structures have a similar origin.
Their presence in these beds indicates that sedimentation was rapid. In some sands
belonging in about the same horizon, and in the same part of the field, were also
to be seen some vertical or slightly oblique perforations more or less perfect, seldom
more than an eighth of an inch in diameter. These are probably either worm borings
of some kind or cavities left by imbedded plant structures.

Some Larger Bedding Structures.

"The fact has been mentioned that the sandstone beds can not with certainty
be traced for any considerable distance. They disappear, frequently, in less than
a mile. Instances of this kind have been referred to in some of the described sec-
tions, as in sections 27, 29, 31, 32, 33 [of this paper]. Another case of this kind
was noted at a point about 3 miles east of Wichita Falls, where the main wagon
road turns up in the low bluff. A silty sand, with a dip that is evidently incidental
to the bedding, terminates against a sloping clay surface. The outcrop is some-
what obscure. Other cases of dipping sandstones, where the dip is evidently
original in the bedding, were noted in survey 27, H. & T. C. R. R. Co., about 6
miles south and 2 miles west of Electra. At this point a sandstone runs some 150
yards with a dip of several degrees to the east, but on all sides of this place the
formation Hes horizontal. Another dip of this kind was noted in the ravines about
2 miles south and i mile west of Electra. In a hill facing northeast near the east
line of the W. W. Carroll survey, some 5.5 miles north and 4 miles east of Iowa
Park, some layers of sandstone, interbedded with red shale, dip some 10 to 15
degrees to south and disappear from the outcrop. Close to the south the overlying
red shale is capped by some thin, gnarly, black limestone, and this lies horizontal.
In all of these cases we believe that the dip is original in the bedding, and in several
cases the evidence is clear that an excavation has been made in the accumulating
clay and sands, and the dipping beds have been laid down on the sloping sides of
the excavation. We believe that these excavations may very well have been made
by bottom currents in littoral waters, for there are no evidences of weathering or
decay along the contacts on the beveled layers. It is well known that sand banks
on the gulf coast are continually undergoing changes, and excavations of several
feet may be made more or less extensive in the course of a year. Tidal currents
are especially effective in such work. The universal occurrence of cross-bedding
in these sandstones, and perhaps also the frequent presence of extensive fiat and
thin lamination which we have described, may perhaps be regarded as additional
evidence of tidal action. We believe that these sandstones were originally mostly
submerged sand-bars, and in some cases sandy beaches. Wave-marks, marks of
rain drops, and rill-marks are not often to be seen. It appears to us that these
should be more frequent if the greater part of these sands were emerged beach
sands.

CONGLOMERATES.

"In all the sandstones examined in Wichita County and in the northwest
quadrant of Clay County, no quartz grain or pebble was noted which was more
than a millimeter in diameter. Coarse ingredients from the same source as the

NORTH AMERICA AND THEIR VERTEBRATE FAUNA. 25

bulk of the sand have been effectively left behind by the currents transporting the
sand. Nevertheless, some coarse sediments were found together with the sands
and the shale, but these are, as we might say, of indigenous origin, and have not
been transported from the same places as the rest of the material in the sands and
the shales. These indigenous coarse sediments may be designated as bone breccias
and mud-lump conglomerates. We shall describe the bone breccias in connection
with the limestones, of which they make a somewhat rare feature. The conglomer-
ate has been noted by all earlier observers in this field. Mr. W. F. Cummins very
aptly referred to it as a 'peculiar conglomerate.' It occurs in most frequent asso-
ciation with sand, quite often appearing as a basal laj'er under sandstone. Quite
frequently it forms separate layers interbedded in sandstone. In the described
sections it occurs interbedded in sand in 8 cases, and underlies sandstone and over-
lies shale in 3 instances. In 4 instances it was found interbedded in shale, which at
least in i case was slightly sandy and stratified. The assertion appears to be war-
ranted that the associations of this conglomerate indicate its formation in situations
where currents in the depositing waters were active. The conglomerate consists of
more or less rounded bodies of indurated and compact calcareous and argillaceous
material. Some of these are calcareous, others argillaceous or ochreous. They
measure from the size of sand grains to an inch and a half in diameter. Many
exhibit an obscure concentric structure, which is most apparent near the periphery.
Many have internal fissures, such as characterize clay ironstone concretions, and
calcareous concretions in clay beds. These balls, as we may call them, are more
or less uniform in size for different beds, having evidently been sorted by the trans-
porting currents. In the coarsest conglomerates noted they perhaps average half
an inch in diameter, and in the conglomerate of finest texture the individual pebbles
averaged less than one-tenth of an inch in diameter. Balls of the size of a pea
are common in samples where the sorting has been the most perfect. These balls
or pebbles are embedded in a matrix of clay or of sand, or of a mixture of these.
The matrix may be only a filling in the interstitial spaces in the conglomerate, but
it constitutes more than one-half of the rock. In some locahties the conglomerate
has evidently suffered alteration from mineralized ground water, in places substi-
tuting copper carbonate, ochre, or wad for the calcareous ingredients in the rock,
and in places merely precipitating these minerals in the original matrix.

"Conglomerates like this are indeed not unknown in other formations con-
sisting largely of clay and shale. They have been noted by one of the present
authors in the late Cretaceous clays in Brewster County in Texas, and in the Penn-
sylvanian in Illinois and Iowa. In Ohio a somewhat similar rock has been noted
and described^ as a 'desiccation conglomerate.'"

"In his paper on the 'Physical Origin of Certain Conglomerates,' J. H.
Gardner'' shows how water-currents which are overloaded with fine mud will form
balls which resemble concretions, and William B. Phillips'' has described how balls
of fine clay are formed in the troughs of the log washers in the treatment of brown
ores in Alabama. That most of the balls which make up these conglomerates have
been formed by a process of rolling appears likely from the concentric structure
which many of them have. But some of the pebbles have evidently withstood
more wear than mere mud balls can do. These must have been considerably indu-
rated originally, and they have the appearance of being true calcareous concretions.
It is believed that such pebbles in the conglomerates may have been washed out

' J. E. Hyde, Amer. Jour. Sci., vol. xxv, 1908, p. 400.

'' Gardner, Jour. Geol., vol. XVL, p. 452.

■= Phillips, Iron Making in Alabama, Alabama Geological Survey, 2d ed., p. 55.

26 THE PERMO-CARBONIFEROUS RED BEDS OF

from clays in which they first were formed by true concretionary growth. The fre-
c]uent association of sandstone and of these conglomerates with contemporaeous
unconformities or local excavations in the clays is significant in this connection.
It is known that concretionary growths may form quite rapidly, and on the Gulf
coast places may now l)e found where the waves are beating down banks of recently
formed clay, leaving thin layers of calcareous concretions mingled with sand on
the beach at the foot of the clay cliff. A sandy conglomeration of such concretions,
that perhaps was laid down on a beach in this manner, was noted in the breaks
about 4 miles south of Electra. The concretions have evidently been embedded
in the upper surface of a stratum of sand, to which they adhere in the exposure.
The absence of everything but indigenous material in conglomerates which clearly
have been produced by currents of considerable strength suggests isolation of the
coasts from mountain lands while the Wichita beds of this region were deposited.
The underlying beds of the Cisco formation contain pebbles of chert and of granite,
which are derived from the Wichita Mountain uplift. Evidently the geographic''
conditions prevailing during the deposition of the Wichita beds were different from
those existing during the making of the Cisco beds."

THE BEAVERBURK LIMESTONE.

"While the clays and the sandstones of the Wichita formation are too irregular
in their development to be individually correlated, at least one limestone was
found which it was possible to follow for a dozen miles or more, even though it
may not be quite continuous for this distance. We have called this the Beaver-
burk limestone, for the reason that it is well developed in the basin of Beaver
Creek, and has been traced northeast as far as to Burk Station on the Fort Worth
and Denver Railroad.

"This limestone caps the upland bluffs on the north side of the Wichita River
in the southwest comer of Wichita County, where it has its greatest thickness and
measures about 3 feet. Its outcrops have been traced from this point northeast-
ward across the basin of Beaver Creek, and from there northward and eastward
to Burk Station, * * *. (See fig. 4, p. t,^,-) In the Beaver Creek Basin the rock is
less than 2 feet thick, and in some places less than a foot. Northeast from the
Beaver Creek basin, and in the vicinity of Burk, it is less than 6 inches thick, and is
evidently not always present in the section. The horizon where it belongs is, how-
ever, marked by a continuation of the dark or greenish-gray shale which underlies.
This shale is traceable eastward as far as to the hills 2 miles northwest of Iowa Park.
A thin shell of limestone, which may be a continuation of this limestone, was noted
at a point on a hillside 3 miles north and 1.5 miles east of Iowa Park.

' ' This limestone is mostly a tough , dark gray rock, that effectively withstands
weathering. It has been used very generally for building stone and in foundations
at the neighboring ranches. It breaks along two main systems of joints into rec-
tangular and sometimes diamond-shaped blocks, often in sizes small enough to be
handled and hauled away. Where the limestone caps a small slope these blocks
creep down on its surface, forming a pavement in which the blocks maintain their
arrangement in rows for some distance down the slope. (See figs, i and 2, plate 10.)
This is frequently seen in the breaks on the Houston and Texas Central Railroad
Company survey 33. * * *

"In its original form the rock is almost compact and structureless, save for
the presence of more or less obscure lamination. Under the microscope the sample
* * * exhibited an exceedingly fine and homogeneous granular texture, the granules

Or climatic. — E. C. C.

NORTH AMERICA AND THEIR VERTEBRATE FAUNA. 27

being somewhere near one-thousandth of a milHmeter in diameter, and appearing
Uke the crystals in a fine-textured dolomite. In the granular matrix various curving
lines were noted, some of which were very thin embedded small bivalve shells.
Several thin sections, cut in three dimensions vertical to each other, of the rock
near Burk, consist largely of a tangle of irregularly bending and branching laminate
structures, about one-twentieth of a millimeter thick. These lie mostly flat with
the bedding planes and enmesh a varying copious matrix, consisting in part of
structureless material, and in part of small lump-shaped bodies of lime. There are
also various shell fragments, and irregularly shaped impregnations of black bitumi-
nous material, scattered through the mass. The structure of the rock suggests that
it has been formed, at this point, to some extent from a multitude of thin shells
incrusted with lime, which became embedded in a calcareous precipitate mixed with
some fine clay. In the Beaver Creek basin and along Wichita River the rock is in
many places somewhat porous, and has a dark brown rusty color. These are evi-
dently secondary characteristics, due to solution and infiltration by the ground water.
Irregular pockets filled with crystalline calcite must be ascribed to the same cause.

GENERAL SECTION OF THE OUTCROPPING ROCKS.

"Reviewing all the observations made on the outcropping rocks, it is to be
noted that less than one-half of all the localities described can with certainty be
referred to their proper position in a general section. The Beaverburk limestone
and the Bluff bone-bed are the only identifiable units in the field. Of these, the
Beaverburk limestone does not extend eastward beyond Iowa Park, and the Bluff
bone-bed is not known to extend farther than 4 miles east of Electra. Only in one
place were the field conditions such that a measurement could be made of the verti-
cal distance between these two key-rocks. This is near the Webb well, just west
of the west boundary of Wichita County, 4.5 miles south of Electra. At this place
a shallow well has recently been made, and a thin limestone, readily identified from
fragments as the Beaverburk limestone, has been penetrated at the depth of about
45 feet. In the low upland near this well, the Bluff bone-bed lies 20 feet above the
curb of the well, so that the distance between these two members in our section
is 65 feet at this place, as shown in section 30 [35 of this paper]. * * *

"The beds above the Bluff bone-bed * * * consist of 30 feet of red clay over-
lain by some few feet of sandstone. This clay is also exposed north of the railroad
a half-mile east of Electra, and in the low bluffs around the artificial lake a mile
west of Electra, as well as in the breaks on the east side of Bluff Creek.

"About midway between the two key-rocks there is at one place on Bluff
Creek a dark bluish-gray, or almost black, shale, only 2 feet thick, in which occur
some flat clay-iron concretions as large as a hand. These, as well as the shale
itself, contain fragments of leaves in which the vegetable structure is unusually
well preserved.

"The sediments below the Beaverburk limestone are seen in several places
in a belt about 5 miles wide, following the north side of the Wichita, from Burk
Station south westward. Such are the strata designated and described as i, 2, 3
in section 21; i, 2, 3 in section 26; i in section 27; and i, 2, in section 28. But in
none of these places are there more than 30 feet exposed of the beds below the lime-
stones. Section 25 [34 of this paper], which is in the north bluff of the Wichita
River, shows the thickest single exposure in the region, and exhibits 125 feet of
the sediments underlying the Beaverburk limestone. In all of these localities there
are a few feet of sandstone at from 25 to 30 feet below the limestone, and in the
deep section on the Wichita River just mentioned there are four such beds of

28 THE PERMO-CARBONIFEROUS RED BEDS OF

sandstone, approximately equal distances apart in the lower 125 feet seen. The
whole succession of beds which it has so far been possible to construct from exposures
is, therefore, as below :

Section of the Wichita beds ktiown front exposures.

Thickness
in feet.

Shales above the BUiff bone-bed 32

Bluff bone-bed 0-5

Shales between the Bluff bone-bed and the Beaverburk limestone 65

Beaverburk limestone 0-3

Shales and sands below the Beaverburk limestone 125

222-230

"It is possible that some of the beds described in the east half of Wichita
County, and in the northwest part of Clay County, are to be correlated with some
part of the above general section, but it does not seem that such correlation can
be made in the usual way. There seem to be no identifiable horizons in this part
of the field, so far as yet determined."

It is evident from the above description, quoted from Udden, that he
believes that a good portion of the Texas Permo-Carboniferous beds were
deposited upon or near a sea-shore affected by variable and local currents.
Also that he believes that the sea was located to the west, or over the beds
discussed, with a land to the east. These ideas are almost diametrically
opposed to those held Ijy the author and to those of most, if not all, of the
men who have written upon the region. Whichever idea may prevail in
the end, it can not detract from the value of the observations made by Udden.

THE CLEAR FORK FORMATION.

The limestones which were considered by Cummins as most nearly
marking the base of the Clear Fork appear for the first time a little east
of the line which separates Baylor and Archer Counties, and extend to beyond
the Big Wichita River, in a nearly north-and-south line. On the north they
disappear beneath the surface deposits beyond Burk Station, and on the
south they may be traced to a contact with the Cisco, near the northwestern
corner of Young County. As stated above, Gordon found it impossible to
distinguish between the Clear Fork and the Double Mountain beds and
includes a large part of what Cummins regarded as Clear Fork in the Wichita.
However this may be finally settled, the fact remains that there is a decided
difference between the faunae of the beds above and below the limestones
(see list, p. g6), and the author of this paper is inclined to use the term
"Clear P'ork" to indicate the series of beds beginning with the limestones
and carrying the upper fauna. Cummins has drawn an approximate line
between the Clear Fork and the Double Mountain, which passes south near
the line between Wilbarger and Hardeman Counties, just west of Seymour,
in Baylor County, and then west of south to or just west of Haskell, in
Haskell County.

Cummins's original description of the Clear Fork is as follows:'

"The Clear Fork, or Middle Beds of the Permian, are composed first of bedded
limestones, magnesian and earthy, which are sometimes carbonaceous enough to be

» Cummins, First Annual Report, Texas Geological Survey, 1889, p. 188.

NORTH AMERICA AND THEIR VERTEBRATE FAUNA. 29

classed as stinkstone. These carry a large and characteristic fauna. They are in
turn overlaid by clays and less fossiliferous limestones and shales. The limestones
become less fossiliferous toward the top of the beds, the clays are both red and blue,
the former color largely predominating. The red clays are in thick beds, and are
in places interstratified with sandy shales. There are also beds of white, red, and
spotted sandstones. Toward the top of the beds they become more sandy, and a
few seams of gypsum occur, but not in the quantity in which it is found in the Double
Mountain beds. There is also the peculiar kind of conglomerate which is found in
the Wichita beds. The red clay contains vertebrate fossils, the bluish clay has
copper, and the limestones have large quantities of invertebrate fossils.

"The fossils mentioned by Dr. White in his article heretofore quoted, published
in the American Naturalist, were taken principally from the Clear Fork Beds. By
reference to the list, it will be seen that it embraces both Paleozoic and Meso-
zoic types, and some that are characteristic and peculiar to the Permian. It will
be seen from the list that the broad-shouldered Brachipods, which were so abun-
dant in the Coal Measures, are wanting."

"These Clear Fork Beds* are composed of limestones, clay and shale beds,
and sandstones.

"The limestones are mostly magnesian and carbonaceous, some of them being
so largely impregnated with carbonaceous matter that when struck with a hammer
they give off a peculiar odor, which has given such stones the name of 'stinkstone.'
These limestones carry an abundant and characteristic fauna.

"The sandstones are not so abundant as in the Wichita Beds, and are not so
massive, but are generally thin-bedded.

"The clays are blue and red, the red occurring in thick, heavy beds. The blue
clays are in places copper-bearing. The conglomerate is similar to that found in
the Wichita Beds, but is not so abundant, and is less compact.

"Toward the top the sandstones become more shaly, and the clays more sandy.
There are also some beds of gypsum, but not in such abundance as is found in the
Double Mountain Beds."

Gordon's first account of Clear Fork formation is included in his de-
scription of the Wichita formation, page lo. A more recent and more com-
plete account by Gordon ** appeared in 19 13:

"Overlying the Wichita formation conformably are red and blue clays, sandy
shales, and sandstones, including deposits of g>'psum and a few beds of earthy
magnesian limestone. These rocks were subdivided by Cummins into the Clear
Fork and Double Mountain beds, but, as stated by that author, 'no attempt has
been made to determine a definite line of division between the two,' and in view
of the character of the sediments, it is evident that the determination of such a line,
if it can be made at all, will require much detailed work. Hill proposed the term
Brazos series to embrace 'all those rocks of Texas, Oklahoma, Kansas, and New
Mexico between the top of the conformable Coleman division of the Carboniferous
beds below (and) the base of the unconformable Cretaceous above,' but the sug-
gestion has not been elsewhere adopted. According to Gould, these beds corre-
spond to those in Oklahoma which he has termed, in ascending order, the Enid,
Blaine, Woodward, Greer, and Quartermaster formations.

» Cummins, Second Annual Report, Texas Geological Survey, i8qo, p. 401.

'' Gordon, U. S. Geological Survey, Water Supply and Irrigation Paper No. 317, pp. 28, 29, 1913.
3

30 THE PERMO-CARBONIFEROUS RED BEDS OF

"In the lower beds red and blue clays predominate, but the upper beds are
characterized by an increase in the proportion of arenaceous constituents and also
of limestone and gypsum. The sandstones and limestones are friable and, together
with the clays, yield readily to eroding agencies and supply a large amount of
detritus to the streams, which are heavily charged with the red sediments brought
down by their tributaries. In the lower beds the gypsum occurs as thin layers
and lenses in the clays. Beds of massive gypsum 2 to 3 feet thick crop out in the
hills south of Quanah. At Acme, where the material is cjuarried, the deposit is
from 10 to 20 feet thick. In many places fibrous g>'psum fills cracks which cut the
alluvial clays in every direction.

"The massive gypsum does not constitute persistent strata, but thins out or
is replaced horizontally by clays or limestones. J. J. Cyrus, a well-driller of Quanah,
states that the wells of that city derive their water from a porous limestone stratum
at a depth of 75 feet and that no g>'psum occurs in the overlying beds, which con-
sist mostly of clay. A well put down a mile south of Quanah passed through a bed
of g\-psum at 40 to 65 feet and another at 75 to 83 feet, the latter apparently the
equivalent of the limestone found in the city wells.

"Except where overlain by fluviatile deposits of Quaternary age, the Clear
Fork and Double Alountain formations constitute the surface rocks west of the
Wicliita formation as far as the escarpment that marks the eastern extension of
the Triassic in Texas.

' ' The age of these beds is generally recognized as Permian. Fossils are scarce and
are confined chiefly to the limestones. The meager collections thus far made from
these beds in Texas are not sufficient to warrant definite conclusions concerning them.

"Cummins has assigned to these beds a total thickness of 3,900 feet, 1,900
feet to the Clear Fork and 2,000 feet to the Double Mountain. Only the lower
beds of the formations are exposed in the Wichita region. Red gypsiferous shales
and sands, with beds of g\^psum and some limestones in the upper part, represent
the formations as they appear here.

"The limestone (No. 3) [section 43 of this paper] is made up of several layers,
some of which are composed largely of fragmcntal remains of vertebrates, including
plates, spines, fish teeth, etc. The stratification of the argillaceous and arenaceous
sediments is very irregular, the sandstones and shales grading into each other both
vertically and horizontally. Moreover, there is a monotonous likeness in both
the sandstones and the shales throughout the area, which, in the absence of per-
sistent, clearly recognizable strata, renders the correlation of beds, except within
very narrow limits, practically impossible.

"Some of the most proininent limestone divisions of the southern area persist,
although in diminished thickness, as far north as Red River, perhaps farther. The
limestones so well developed on Clear Creek, in the southwestern part of Throck-
morton County, extend northward through Seymour, are crossed by Wichita River
about 3 miles east of the Seymour- Vernon road, and are last seen on Beaver Creek,
in the eastern part of Wilbarger County. The transition of limestone into sandstone
is well marked in an exposure in the bluffs of the Salt Fork of Brazos River, about
a mile west of Spring Creek post-office, in the northwest comer of Young County.
A bed of limestone 3 feet thick and an overlying bed of blue shales 5 feet thick,
both filled with fossils (chiefly Alyalina permiana), are replaced within a distance
of 200 yards by a light-colored cross-bedded calcareous sandstone having a maxi-
mum thickness of 15 feet. The transition is rather abrupt in appearance, but the
sandstone contains much lime and also some fossils. Farther along the limestone
reappears as before.

NORTH AMERICA AND THEIR VERTEBRATE FAUNA. 3I

"The limestones of the Wichita formation are for the most part highly fossil-
iferous, though in many of the beds good specimens are hard to obtain. A list
of the invertebrate fossils obtained from these beds has been published elsewhere.
(vSee table 2, page 106.) Collections of vertebrate remains have been made at various
times in Archer and Baylor Counties. A list of localities where the earlier collections
were made is given by Cummins. In many places the remains are found at the surface,
having weathered out of the clays or lime beds. Certain strata, called the 'bone-beds,'
have furnished most of the material. A chalky friable limestone exposed in a
railway cut just west of Mabelle Station, in Baylor County, is filled with fragments
of vertebrate remains allied to Eryops, mostly indeterminable. In a recent paper
Williston announces the discovery of a new genus and new species of amphibian
allied to Eryops, which he names Trcmatops millcri. This specimen is said to have
been found on Craddock's ranch, near Seymour. The figure of the skull given by
Williston shows a close correspondence to one found by the writer in the friable
limestone at the railway cut near Mabelle, which was unfortunately broken and
in part lost before opportunity was given for identification. It seems probable
that both came from nearly the same horizon."

THE DOUBLE MOUNTAIN FORMATION.

Cummins's original account'' of this formation is as foUovi^s:

"The Double Mountain, or Upper Beds of the Permian, are composed of sand-
stones, sandy shales, limestones, red and bluish clays, and thick beds of gypsum.
The limestones are quite earthy, and are often very full of the casts of fossils, the
newer types largely predominating. The shales are often highly impregnated with
common salt, and none of them are free from gypsum. The sandstones are red,
gray, and spotted, and are generally very friable. The gypsum beds are numerous,
and often very thick, and the seams of fibrous gypsum traverse and transect the
clays and shales in every direction, ranging from paper-Hke seams to those 10 inches
in thickness, and often making a perfect network of seams. Toward the western
boundary of these beds, the strata are much distorted and folded. It looks as if
there had been a hea\y lateral pressure from the west, crumpling the strata into
short folds. In the gypsum, the folds are often only an inch or two across."

"The beds'' are composed of sandstones, sandy shales, red and bluish clays,
and thick beds of g>'psum. The Hmestones are generally of an earthy variety, and
in places have many casts of fossils, the newer types being more largely represented
than the older. The gypsum beds are numerous and many of them very thick.
All the clays and shales are impregnated with gypsum, and many of them carry
a large percentage of common salt.

"The sandstones are very friable, and are of various colors, red, white, and
spotted."

The author has found it very difficult to draw^ any exact line between
the Clear Fork and the Double Mountain, but is in agreement vi^ith Cummins
that there is, west of the line described by him (Cvunmins), a decided change
in the character of the sediments. This change is, however, rather gradually
accomplished. As far west as Haskell there is a conglomerate very similar,
both in character, thickness, and coloration, to the layer described as the

* Cummins, First Annual Report, Geological Survey Texas, 1889, p. 188.
•■ Cummins, Second Annual Report, Geological Survey Texas, 1890, p. 402.

,2 THE PERMO-CARBONIFEROUS RED BEDS OF

Wichita conglomerate.^ It is traceable in the breaks of the small creeks
which form the main exposures in the region. North of the Big Wichita
River this layer is very persistent, and forms a good reference horizon (see
plate 8, fig. 2). Above it are 100 to 200 feet or more of red clays, sandstones
and conglomerates, carrying typical Clear Fork vertebrates. (Here are the
Cacops beds of Williston, Lysorophus beds, etc.) On the north side of the
Big Wichita, the beds above the Wichita conglomerate appear as prominent
bluffs capped with a heavy conglomerate or sandstone. West of Haskell
the land is level and the rocks are concealed by a considerable thickness of
surface soil, but at Sagerton, some 12 miles southwest of Haskell, the bluff
shows at its foot cleaner clays, with little conglomerate and a much more
regular and even stratification; at this place appear also the first layers of
satin spar which are so characteristic of all the Permo-Carboniferous beds
above the Clear Fork. The gypsum which occurs in the Clear Fork Beds
is in local patches, and far from alnmdant. Evidently there was a serious
change in the conditions of sedimentation between the Clear Fork and
Double Mountain time. All along the line drawn by Cummins separating
the formations, the difference between the beds may be recognized within
a mile or more by the characters described.

OCCURRENCE OF FOSSIL VERTEBRATES.

Vertebrate fossils arc not found through all of the Wichita formation,
but have been collected from the whole thickness of the Clear Fork. If a
line be drawn south from the Big Wichita River, a little east of Holliday in
Wichita County, east of Archer in Archer County, and continuing for an
undetermined, but not great, distance south of the latter place, it will mark
the east line of the occurrence of vertebrate fossils in the Wichita.'' A con-
siderable thickness of deposits only to be reckoned as belonging to the
Wichita lies below the beds mentioned.

Fossils occur in the Clear Fork to its upper limit, for Cummins reports
finding bones on Paint Creek, a few miles south of Haskell. North of Haskell
vertebrates have been found for only a few miles west of the road from
Seymour to Vernon.

Any attempt to describe the beds in which the vertebrate fossils occur
is fraught with the greatest difficulty, as they are in the highest degree dis-
continuous; only the fossil hunter, whose success may depend on following
a single layer, can realize the impossibility of tracing any one of the layers
of sandstone, clay, or conglomerate for more than a very short distance.
Perhaps the best general idea of the beds may be gained by realizing that
the limestones outcrop with a strike a little east of north, and a gentle
westerly dip; though they can not be traced continuously for more than a
mile or so, they indicate the general lie of the beds, which are in general

'Case, Bull. Amer. Mus. Nat. Hist., vol. xxili, p. 662, 1907.

>> A recent letter to the author from Dr. C. L. Baker of the University of Texas reports the discovery
of a small skull of Cardiocephatus from Halsell in central western Clay County.

NORTH AMERICA AND THEIR VERTEBRATE FAUNA.

roughly parallel with them. Between and above the limestones lie heavy
beds of red clay, with local developments of cross-bedded sandstones, con-
glomerates, patches of blue clay, etc., in inextricable confusion. In the
valley of the Little Wichita, just beyond the beginning of the breaks south
of Dundee, an outcrop of shaly sandstone may be traced in a direction
totally at variance with the general strike of the liniestones. In the spot
mentioned, the strike of the sandstone is almost directly northwest-south-
east, and is not in accord with the strike of the beds above and below them.
Numerous examples of this kind covild be cited. (See plates 5-10.)

Fig. 4. — Map showing location of sections given in text.
SECTIONS.

The following series of sections taken by various workers in the Texas
area will give some idea of the general character of the beds. Their location
is shown in fig. 4. As in other localities in the Red Beds of the Permo-

34 THE PERMO-CARBONIFEROUS RED BEDS OF

Carboniferous and much of the Triassic in this country, sections taken at
one locaHty are not to be depended upon as representing the succession at
another, even within a quarter of a mile.

Section i. — Taken 2 miles west of Wichita Falls (Case). Surface covered
with rough ironstone concretions and rounded pebbles of quartzite.

Feet-

3. Fine red clay i-

2. Purple sandstone; shaly above; gray and more massive below 6

1. Red clay; bottom not seen.

Section 2. — Taken 2 miles west of Wichita Falls (Cummins). p^^^

2. Red clay, with nodular iron ore 30

1. Sandstone; thin-bedded 4

Section 3. — Hill about 12 miles west of Wichita Falls (Cummins). p^^^

4. Red Bed clay 20

3. Conglomerate, fossiliferous i

2. Red clay, with iron nodules 20

1 . Sandstone, thin-bedded 4

"It must be remembered that the conglomerate mentioned in the sections is
the peculiar Permian conglomerate, composed of small round pieces of iron ore and
clay cemented together by iron." ^

This statement applies only to the sections by Cummins in the eastern
exposures of the Wichita, not to the conglomerate mentioned by Case in
the western (higher) exposures of the Wichita, and in the Clear Fork.

Section 4. — Taken 3 to 4 miles southwest of HoUiday (Case). p^^^

4. Coarse brown conglomerate, overlying and replacing a shaly or massive

sandstone, blue-gray in color 5

3. Red and brownish clay ^ 20

2. Brown and gray shaly sandstone and pea conglomerate (Cummins's "pecu-

liar conglomerate ") ; some fossils 2-5

1. Red clay, bottom not seen.

Section 5. — Com Hill, or Tit Mountain, a little northeast of Dundee
(Cummins) . p^^t

4. Red clay 6

3. Conglomerate 8

2. Red clay 3°

1 . Thin-bedded sandstone 4

Section 6. — Taken i mile west of Com Hill (Cummins). p^^^

2. Thin-bedded sandstone 4

1. Red clay .• 30

Section 7. — 3 miles east of the Dundee-Archer road, i mile or so south of
the Little Wichita (Case). p^^t.

5. Shalv sandstone, overlain by local patches of heavj% brown conglomerate. . .5 to 15

4. Red clay 20

3. Shaly sandstone; gray, changing to red 5

Inches.

2. Thin layer of pea conglomerate, "peculiar conglomerate" 2 to 3

1. Red and variegated clay, with local beds of light bluish-green clay, carrying

amphibian and fish bones; bottom not seen.

Section 8. — Taken on east or south side of Godlin Creek, just beyond its
juncture with the Little Wichita (Case). p^^t

3. The capping rock a sandstone of varv'ing thickness, underlain by the usual

conglomerate, which is here quite thick.

2. Blue and red clay, with bones 2

I. Northeast, along the ridges, the clay plays out, and a lower conglomerate

comes up to the base of the sandstone. On the cast side of the Archer-
Dundee road the sandstone becomes very heavy for a short distance.

'Cummins, Second Annual Report, Geological Survey Texas, 1890, p. 403. • ■

NORTH AMERICA AND THEIR VERTEBRATE FAUNA. 35

Section g. — Northwest comer of Archer County (Gordon).

" Outcrops of limestone are found on the boundary between Archer and Baylor
Counties. Some beds of the limestone at the top of the escarpment on the west side of
Horseshoe Lake. The limestone is earthy, dark blue, and weathers to a dark bro^vn or
black. The limestone is underlain by 4 feet of blue clay, and this by 100 feet of red con-
cretion-bearing clay, with a limited develoiomcnt of red and white limestone. From this
comer west the stratification is more rcgrdar; blue shales alternating with predominant red,
and an occasional bed of impure limestone."

Section lo. — Taken near the Bar X Ranch crossing of the Big Wichita.
Northeast comer of Baylor County (Case). Several ledges of hard
limestone separated by varying thicknesses of blue shale and red clay.

Section II. — Taken near the railroad just west of the line between Baylor
and Archer Counties (Case).

^ ' Feet.

4. Conglomerate 2

3. Blue clay 4

2. Conglomerate i

1. Red clay 30

Section 12. — Northeast of Fulda, about 2 miles (Case).

' ^ ' Feet.

3. Limestone and blue clay 3

2. Limestone 2

1. Red clay 30

Section ij. — Taken at Fulda (Case).

2. Conglomerate 6 inches.

1. Red clay 20+ feet.

Section 14. — Taken in large breaks i mile southwest of Fulda (Case).

3. Red clay, with iron concretions 6 to 8 feet.

2. Light gray shaly sandstone (Fulda sandstone) 2 inches to 2 feet.

1. Variegated clay; uniformly, from above downward, greenish blue, dark red,

bluish, purple; gray, scarce fragments of bone in isolated patches of blue

clay 20+ feet.

The same section is found i mile north of Fulda, but the sandstone is
more massive, and, in places, harder. Approximately the same section is
found also 5 or 6 miles west of Fulda, and traceable to the Little Wichita.

Section 15. — About 2 miles directly south of Fulda (Case).

5. Coarse conglomerate 2 to 4

4. Light red, fine-grained clay, mixed with pebbles 20

3. Dark-red clay, with coarse, rough iron concretions 20

2. White s.andstone (red streaks), persistent over large area I to 3

1. Red, white, and yellow clays; bottom not seen.

Section 16. — About i mile north of the bridge over Godlin Creek, on the
Archer-Seymour road (Case).

5. Brown limestone; forms a prominent shelf 6 inches.

4. Fine, red joint clay 20 to 40 feet.

3. Whitish to gray sandstone (Fulda sandstone) 6 feet.

2. Brown limestone, filled with small bones; forms a second shelf 6 inches.

1. Red clay; bottom not seen.

Section 17. — About 10 miles west of section 16. This is the section of a
high hill, about 3 miles southwest of the old Crewthird place, and
almost directly south of the town of May belle (Case).

5. Light yellow limestone (the same limestone appears on the hills crossed

by the Archer-Seymour road a mile or so west of the bridge over the

Little Wichita) 6 inches.

4. Yellow clay, changing to red 30 feet.

3. Red clay 20 teet.

2. Sandstone, variable red and white, shaly and massive 4 feet.

I. Red clay; bottom not seen.

,6 THE PERMO-CARBONIFEROUS RED BEDS OF

Section i8. — Less than a mile east of the bridge over the GodUn Creek
on the Archer-Seymour road. Near the old Ek. Brown place. There
is an oil-prospecting derrick near the spot now (191 3) (Case).

Feet.

3. Sandstone 3 i

2. Red clay 30

1 . Gray and blue clay 2°

Section IQ. — Near the head of Godlin Creek (Case).

6. Gray clay 6 feet.

5. Limestone 6 inches.

4. Grav clay 4 feet.

3. Deep red clay, turning to blue below 45 leet.

2. Whitish sandstone (Fulda) 5 feet.

1. Red clay; bottom not seen.

Section 20. — A generalized section near the Seymour- Vernon road, north
of the Big Wichita (Case).

6. Red and blue clay, and sandstone 60 to 100 feet.

5. Purplish-green, fine conglomerate (Wichita) 6 to 12 mches.

4. Red clay, with calcareous nodules 20 to 30 feet.

3. Purple and green clay 25 to 30 feet.

2. Limestone: .

a. Thin limestone, broken into small blocks 2 mches.

h. Blue clay 6 feet.

c. White limestone 2 feet.

I. Blue and gray clay; bottom not seen.

Section 21. — Blufi 2 miles east of Seymour- Vernon road. North side of
the Big Wichita (Cummins).

Middle of the section red and concretionary clay and sandstone. The lower two-thirds
red and blue shale, alternating with beds of limestone. Locally the thin-bedded lime-
stone shades into more massively bedded limestone.

Section 22.— South side of the Big Wichita, 4 miles west of the east line
of Baylor County Cummins). p^.^t

4. Red clay 30

3. Limestone ^

2. Blue clay 4

1 . Limestone '

Section 23. — South side of the Big Wichita, 2 miles west of the east line
of Baylor County (Cummins). p^^t

4. Red clay, with nodular concretions with fossils 3"

3 . Bone conglomerates '

2. Blue clay 4

I . Conglomerate (iron ore) ^

Section 24. — iK miles southwest of Wichita Falls, a low bluflf facing west
and south follows the east side of an irrigation canal (Udden).

"This bluff consists of 5 feet of red and blue shale. There is also soine conglomerate.
The sandstone is typical of this region. It consists of mostly white and subangular quartz,
but with some red' and pink grains It is frequently cross-bedded, and the cross-bedded
layers alternate with thin, straight layers, Iving horizontally. Some of these show extended
surfaces, almost perfectly plain and smooth. Some spherical concretions were noted m
which the grains of sand were cemented together with calcite, or with oxides of iron and
manganese. The thickest homogeneous or unstratified layer noted was 2 feet. Under the
sand in some places and interbedded wth the lower part of the sand m another place were
layers of conglomerate mostly less than a foot thick. This consists of lumps of limy and
marly materials and lumps of clay, mostly from one-half to one-third inch m diameter. The
shale is red, with bluish-white streaks and blotches. In one place it was cut by a vertical
vein of hard, red calcareous material one and one-half inches thick."

NORTH AMERICA AND THEIR VERTEBRATE FAUNA. 37

Section 25. — In the south bank of the Wichita River, about 0.75 mile
southwest from the Fort Worth and Denver Railroad bridge, the bed
rock is exposed for a considerable distance, and extends up into the
bluff (Udden). The exposed section is as follows : ^^^^

7. Thin-bedded red sandstone of fine texture, consisting of straight, smooth, and

persistent layers from one-eighth to one-half inch thick 4

6. Red shale, with thin blue layers containing streaks of conglomerate, consist-
ing of calcareous concretions mixed with lumps of clay, both kinds averaging
one-fourth inch in diameter 2

5. Red shale, containing scattered concretions of from one-third inch to 3 inches
in diameter; many of the largest concretions have an irregularly mammil-
lated surface 25

4. Sandy brown shale i

3. Sandstone, laminated and wavy-bedded 6

2. Shale, brown and blue, in places consisting of lumps, as if brecciated, or as if

it were a conglomerate of mud lumps 1.5

1. Brown and blue shale with lentils of sand, one foot thick, extending down

below water level in the stream 3

Section 26. — Near the pavilion, at the north end of Wichita Lake (Udden).
The strata seen consist of: „ .

Feet.

4. Gray sandstone 2

3. Red clay , 8

2. Soft white sandstone 3

I . Red clay 2 -f-

15 +

Section 2y. — About 4 miles south of Burkburnett the Wichita Falls and
Northwestern Railroad bed is cut into a low hill a mile south of the
main creek running east into the Red River (Udden). The west bank
of this cut shows some cross-bedded sandstone which lies in an old
channel evidently cut into the red clay by the currents which de-
posited the sand. It appears that the current was shifted northward,
as there was a greater filling-in of sand on the north side. The current
must have been thrown back and forth, for along one plane in the
main sand deposit on the north side it is clear that the sand below
this plane was eroded before the overlying sand was deposited. Later
the entire channel was filled with red clay. (See fig. 5, p. 39.)

Section 28. — In the Red River bluflfs, on the A. A. Durfee survey, almost
due north from Iowa Park, outcrops of the Wichita beds are seen for
a distance of some 2 miles (Udden). A section was taken where the
bed-rock is highest, and this is as below: p^^^

10. Dark red sandy shale, with seams of dark red sandstone from i to 2 inches thick 8

g. Laminated dark red sandstone 1.5

8. Conglomerate of concretions and lumps of mud, dark red, with thin inter-
calated layers of sandstone 3

7. Laminated and cross-bedded rusty red and gray sandstone 2

6. Red clay, with a 6-inch stratum of calcareous light blue shale 10 feet above
its base; the red clay contains blotched gray concretions a half-foot in

diameter 15

5. Gray calcareous and sandy rock 1.5

4. Red shale, in part sandy 15

3. Calcareous sandstone, with fragments of fossils, in places with many sizes
and kinds of concretions; the lower side of this stratum has combs or

narrow projecting ridges which fit in the underlying clay I

2. Variegated shale, with calcareous concretions 6

I. Red shale 12

The calcareous seam in No. 6 of the above section w^as noted 0.5 mile
farther west, in the Vjluff.

38 THE PERMO-CARBONIFEROUS RED BEDS OF

Section 2Q. — In the west side of the road running north and south along
the east side of B. S. & F. survey, i mile west of vSchool No. 9, and
about 9 miles north and 2 miles west of Iowa Park, there is a thin
shell of light gray limestone overlying some gray shale (Udden). This
limestone contains unrecognizable organic fragments throughout, and
a small coral and a fish-scale were noted. It changes into a sandy
calcareous rock in a short distance to the northeast. A thousand
feet to the northeast from this place there is an exposure in the east
bank of the creek, which probably lies 20 or 30 feet below the above
limestone. In this exposure is seen a typical instance of contempora-
neous erosion in the Wichita formation. A thin gravel of washed con-
cretions lies on a contemporaneously eroded bed of red shale, and over
this, 0.5 foot of shale and then 3 feet of sand, with another streak of
soft conglomerate. (See fig. 6, p. 39.)

Section JO. — In the south end of the T. E. & L. Co. survey abutting on
Red River, about q}^ miles west of School No. 9 and 9 miles west of
Burkbumett. A section appearing in the right bank of Calvary Creek
is as follows (Udden) : ^^^^

6. Sandstone and concretion conglomerate I

5. Ashen gray and red shale 5

4. Streaks of sand and concretionary conglomerate 2

3. Ashen gray and red shale 10

2. Streaks of shale, with indistinct remains of vegetation i

1. Gray shale, with streaks of sand and concretionary conglomerate . . 2

Section ji. — Near the north boundary of the C. T. R. R. Co. survey
abutting on Wichita River, about 6 miles west and 1.25 miles south
of the railroad station at Iowa Park, there is an eroded bluff showing
the following section (Udden) :

4. White sandstone, in part cross-bedded 4

3. Red clay with many concretions and here and there some sandy streaks. ... 15

2. Red sandstone, with cross-bedded structure; terminates somewhat abruptly

when followed westward 10

I. Red shale with white streaks, and with some thin layers of a conglomerate

consisting of worn concretions, evidently assorted 15

The lower sandstone, or a sandstone having the same level in the red
shale, runs south in a low escarpment for almost a mile, and is again well
exposed in some bluffs just south of the main wagon road. At this point
it was seen to contain an impression of a fern leaf, like Pecopteris tenuinervis
F. and W.

Section J2. — In block 314 of the Waggoner Colony survey, about 7.5 miles
north and 4 miles east of Electra, in the right bank of China Creek,
is an exposure of red clay and sandstone, which shows unconformities
in bedding (Udden). Farthest east is a bank of red clay, some 30
feet high, and this is capped for most of its length by several feet of
sandstone. At its eastern edge this sandstone terminates against a
rising slope of the clay, like the bank of an old channel. At the west
end of the exposure two rising sandy layers have been cut ofT in the
excavation of a contemporaneous channel, or hollow, which later has
been filled with sand. (See fig. 7, p. 39.)

NORTH AMERICA AND THEIR VERTEBRATE FAUNA.

Section jj. — In the bluffs on the north side of Beaver Creek, on the
Houston and Texas Central Railroad Company survey No. 35, about
7.5 miles south and 2.5 miles east of Electra, the following section
was noted (Udden) :

8. Conglomerate of late Tertiary (?) age 3

7. White sandstone, top of Wichita beds in this section 7

6. Sandy gray shale 4

5. Red shale 10

4. Gray shale, with shells of lime and sand 6

3. Dark gray limestone 1.5

2. Gray and bluish gray shale -j

I. Red shale containing at 18 feet from the top a 9-foot white sandstone which

runs out in the section in a short distance to the east 33

71-5

Fig. 5.— Section in cut along the Wichita Falls and Northwestern Railway, 3.5 miles south of Burkburnett,
Wichita County: a. red shale; b, cross-bedded sand; c, erosional unconformity; d, alternating layers
of silt and sand. (From Udden.)

Fig. 6.— Wichita beds exposed in bank of creek in Central Texas Railway Company survey, 9 miles north and
2 miles west of Iowa Park, Wichita County: a, shale; b, conglomerate; c, sandstone. (From Udden.)

Fig. 7. — Exposure in right bank of China Creek in Block 314, Waggoner Colony sur\fey, 7.5 miles north
and 4 miles east of Electra, Wichita County. Two sandstone beds, rising from left to righ*-, have been
beveled off; some clay was later deposited on the eroded slope; the depression was later filled with
sand, which overlaps at the right. (From Udden.)

Section 34. — In the north bluff of the Wichita River, near the west line
of the L. T. Miller survey, about 11 miles south and i mile east of
Electra, is the highest single exposure of the Wichita beds in Wichita
County (Udden). It measures 130.5 feet, and is as below: ^^^^

17. Gray shale, with thin shells of lime 3

16. Gray limestone of fine te.\ture 2.5

15. Bluish-gray shale, weathering yellow 16

14. Sand and shale, purplish in color 3

13. Blotched gray and red shale 2

12. Gray sand, cross-bedded 5

II. Yellow and red clay, mostly red in the upper part 23

10. Dull red, silty, soft sandstone, mingled with gray layers 5

9. Gray, muddy shale, cross-bedded sandstone and conglomerate consisting

of concretions 4

8. Red clay with some gray blotches 10

7. Red clay 16

6. Sand and mottled clay 2

5. Red clayey shale 17

4. Gray sandstone, soft i

3. Red soft sandstone, cross-bedded 8

2. Blotched gray and red shale, with layers of gray sand, from one-eighth to

one-half inch thick 2

I . Mottled brown and gray shale, mostly brown II

130.5

40 THE PERMO-CARBONIFEROUS RED BEDS OF

Section 35. — A section near the northwest comer of the Houston and Texas
Central Railroad Company survey No. 27, about 4 miles south and
2 miles west of Electra (Udden). p^^^

3. In a well bored for water near this place a dark gray thin limestone was pene-
trated at the depth of about 45 feet. Fragments of this limestone were seen
on the old dump, and it was clearly identical with the Beaver Creek lime-
stone. The curb of the well is about 20 feet under a calcareous stratum
containing fragments of vertebrate bones, capping a low bluff near this
place. The beds between this layer and the limestone in the well consist
of red and blue shales, with some sandy layers and streaks of black shale.
This shale contains some black impressions of plant leaves. Calcareous
sandstone or a concretionary layer caps the adjacent low bluffs i

2. Red and blue shale, the latter with plant remains, partly exposed, and also

partly explored in the well 65

I. Dark gray limestone, containing Syringopora and Estheria minuta Jones. ... I

Section 36. — BluflF on west side of Horseshoe Lake, Wichita County, Texas
(Gordon). p^^,

II. Limestone, hard, dark blue, brown on exposure, cavernous 4

10. Blue clay 4

9. Red concretionary clays 25

8. Soft red shaly sandstone 15

7. Red concretionary clay 4

6. Red shaly sandstone 9

5. White and red variegated sandstone, more massive than Nos. 6 and 8 6

4. Nodular clay ("conglomerate") i

3. Red concretionary clay 15

2. Nodular clay or "conglomerate" 33

1 . Red concretionary clay 25

108.33

Section 37. — Seymour, Texas (Gordon). p^ j^^^

20. Light reddish sandy soil at surface, underlain by dark-red sandy soil . . 20 to 25

19. Blue shale, with thin ledges of magnesian limestone 6

18. Limestone in massive beds, passing horizontally into shaly beds 5

1 7. Dark clay shale i 6

16. Concretionary calcareous shale and limestones o 6

15. Limestone in two massive ledges separated by I to 4 inches of blue clay shale. 3

14. Blue shale 10

13. Argillaceous limestone and dark blue shale 3

12. Limestone with varying proportions of shale 4

1 1 . Blue clay 3

10. Red clay 5

9. Blue clay 2

8. Limestone 2

7. Blue clay shale 5

6. Limestone o 6

5. Blue clay shale 4

4. Limestone i 6

3. Blue shale, with lenses of limestone 3

2. Blue clay shale, interbedded with thin limestone 2

I . Li mestone 16

102

Section j8. — At the southeast corner of the Walker- Harvey survey, 2.5
miles northeast of the Union Station at Wichita Falls, a sandstone 1 2
feet thick is seen in the low bluff. This sandstone rests on some 20
feet of red and gray shale (Udden).

Section 39. — In the cut of the Missouri, Kansas and Texas Railroad, on
a hill about i mile east of Wichita Falls, a sandstone is exposed which
is composed of alternations of flat laminated layers and cross-bedded
layers from 2 inches to a foot thick. Some of the uppermost layers
are black from impregnations of iron and manganese oxide (Udden).

NORTH AMERICA AND THEIR VERTEBRATE FAUNA. 41

Section 40. — Section in the east bluff of Wichita River, 0.75 mile north-
west of Byers, Clay County (Udden).

4. Gray sandstone, with a 6-inch layer of concretionary conglomerate, greenish-
gray in color j „

3. Red clay g

2. Bluish-green shale [ 5

I . Talus I c

44
Section 41. — In a low bluff facing east, at a point about 3 miles west of
Henrietta, Clay County, 0.5 mile south of the Fort Worth and Denver
Railroad, there are some beds that have been explored for copper,
which occurs in the forms of malachite, azurite, and gray copper
sulphide (Udden). The copper has accumulated mostly on the under
surface of some carbonaceous clay bands, in cavities once filled with
plant remains, and also in some joints in sandstone. The section
exposed, partly in an old excavation, is as follows :

9. Sandstone o

8. Black shale „

7. Sandstone containing carbonaceous shreds of leaves and other vegetation o 6
6. Black shale, with a more or less continuous infiltration of copper ore

against its lower surface o ,

5. Sandstone, containing shreds of vegetation o 6

4. Blackshale, with frequent incrustations of copper ore on the lower surface o 2

3. Shale and sandstone 2

2. Sandstone, impregnated with copper along some joints and containing
some impressions of tree-stems and other remains of vegetation, which
are partly filled with copper ore 2

I . Shale ' J r

14+ 8

Section 42.— About 3 miles northeast of Wichita Falls, in Clay County, a
low bluff, facing westward, runs for almost a mile in a general north
and south direction (Udden). At the north end the strata exposed
in this escarpment form an isolated butte. The section in this butte
is as follows ;

_ Feet.

5. Oray sandstone, soft and homogeneous in some places, in other places con-

cretionary, cross-bedded, or cemented by interstitial lime to a hard rock-

this sandstone forms the cap of the escarpment; maximum thickness ' 8

4. Gray and blotched brown shale, sandy in places, and containing calcareous

concretions 0

3. Red shale, with here and there gray blotches and streaks. '.'. u

2. Gray sandstone, much cross-bedded, partly straightly and thinly laminated ' t.

1. bhale, gray and brownish, with many dark, calcareous concretions 15

45
Section 43. —Cassil Hollow, 2.5 miles south of Fulda, Texas (Gordon).

6. Sandstones, thin-bedded, shaly, with a fine exhibition of ripple-marks; repre-

sents the top of the section and grades into No. 4 6

5. Blue and yellow laminated clay and sandy shale, grading horizontally' into
white shaly sandstones, same as No. 6; the plants were found in a thin
shale stratum near the middle of this division 6 c:

4. Hard bluish limestone which weathers to a brown; apparently the equivalent

of a limestone which outcrops on the Wichita nearly due 'north from this
locality at the Bar X Ranch; contains an abundance of fragments of
vertebrate remains, but all in such a comminuted condition as to be inde-
terminable

3. Blue clay shales

2. Red clay shales; same as No. 3, except in color. . . . . . . .'.........[. 4

I. Gray sandy shales and sandstones to bottom of ravine . . . . . . 15

36.5

42 THE PERMO-CARBONIFEROUS RED BEDS OF

CLIMATIC VARIATIONS RECORDED IN THE PERMO-CARBONIFEROUS BEDS OF TEXAS.

It is apparent from the foregoing that the Red Beds of Texas terminated
on the east in a Hmestone-forming sea. There was over north-central Texas
and central Oklahoma a great, flat area bordering the eastern sea. This
area received abundant terrestrial deposits from higher lands to the north
and west, but was of such slight elevation that it was subject to local inunda-
tions, both by marine waters, due to slight oscillations of level, and by
fluviatile waters during humid phases of the climatic oscillations. Within
the hmits of the eastern sea there are limestones with frequent intercalations
of sandstone and sandy shales, and with occasional beds of clay, such as
would occur in the deposits of a low and partially or recurrently flooded
region. That the whole area was not subject to large movements due to
periodic changes of level of considerable magnitude is shown by the badly
mixed and discontinuous character of the beds. No prevailing continuity
of the beds can be traced, but a study of sections i, 2, 8, and others (pp.
34-41) shows a considerable thickness of red clay and sandstone as the first
dominant series of deposits in the lower Wichita. One thing is apparent in
both Texas and Oklahoma: the limit of red color transcends the beds far
east of where the clastic material gives place to organic deposits and is
noticeable for a considerable distance in the hmestones.

The most generally accepted hypothesis for the explanation of the pres-
ence of a red color in various deposits regards it as due to the mature weather-
ing of iron-bearing i-ocks in a fairly humid region, with alternations of relative
drought and humidity. There is nothing in the Red Beds of Texas to oppose
this hypothesis or to support the alternative hypotheses that the color is
due either to the oxidation of the iron subsequent to its deposition or to
the dehydration of a limonite by the pressure of superincumbent layers, at
least so far as the author has been able to determine. It is here accepted
as the working principle in the study of the cUmate of the region and period.

EVIDENCE OF CLIMATIC CONDITIONS IN WICHITA TIME.

Few plant remains have been recovered from the eastern (lower) expo-
sures of the Wichita, and while this is not positive evidence of the absence
of vegetation during the first part of the period, the rarity of the remains
lends weight to the suggestion given by the prevailing red color, of a lack
of carbonaceous debris in the deposits.

While conglomerates are not lacking in the lower Wichita, they are not
of the same character as those appearing farther to the west and higher m
the series. The first conglomerate above the lowest series of Red Beds is
described by Cummins as a "peciiliar conglomerate," consisting of fragments
of clay and iron ore, cemented by iron. This conglomerate is constantly
referred to in my notes as the "pea conglomerate." Gordon interprets it
as formed of fragments which have been broken up by wave action and re-

NORTH AMERICA AND THEIR VERTEBRATE FAUNA. 43

cemented, but I am inclined to think that it may be explained otherwise.
The "peculiar conglomerate" consists of small pebbles of about the size of
a large pea, mostly a light brown clay ironstone, frequently concretionary
in character, or weathering in concentric layers. The cement is limonitic.
For the purposes of this paper it may be best to refer to it hereafter as the
limonitic conglomerate. This conglomerate appears in sections i, 2, 4, and
7, but does not appear again as a bed of any extent farther west, i.e., higher
in the series. It must not be assumed that its appearance in the sections
mentioned indicates a continuous bed between them. It is altogether prob-
able that it does not, and in several places the recurrence of the same
material is demonstrable.

The iron of secondary deposits is taken from the original minerals in the
zone of weathering (according to Van Hise and others), either by direct
conversion of the iron into ferric oxide, insoluble except in the presence of
CO2 or humic acids, or by conversion into iron carbonate and then into
limonite or other compounds. Limonite is formed from the carbonate by
the action of oxygen in limited cjuantities, and is deposited below or near
the water-level, where high oxidation is not likely to occur.

We may be certain that the red clays of Texas, with their ferric oxide,
were deposited in the sea, or other bodies of water, in the condition in which
they now occur, and are not due to subsequent dehydration or decarbonation,
because (i) the color is uniform throughout; (2) because there is a solidity
and density in the clays, and a lack of filled seams and veins, which would
be impossible after such changes, which involve a decided decrease in volume;
and (3) because the red color transgresses into the limestones and sandstones
with marine fossils. The ferric condition of the iron may be due to either
the original formation of the ferric oxide from the iron-bearing minerals or
to the oxidation of carbonates in the course of prolonged transportation over
semiarid or, at least, well-exposed fiats previous to deposition.

The presence of limonite seems to indicate a higher level of the ground-
water of the flats, for under such conditions the hydrated oxide derived
from the carbonate would not be so likely to make long journeys exposed to
the oxygen of the air. Thus we have an indication of a local increase in
humidity during an interval of time represented by the limonitic conglomer-
ates and associated light-colored clays and sandstones. The following state-
ment from BarrcU =" bears directly upon this point :

"Sediment carried by rivers is subject to oxidation both while in transit and
after deposition on the surface of the flood plain, until its burial by overlying layers
carries a stratum below the level of ground-water. Where the ground-water level
is coincident with or higher than the surface, organic matter accumulates and de-
oxidizing processes take place. A certain fraction of delta deposits, depending on
the proportion of back swamps and coastal swamps, therefore show colors ranging
from green to blue, according to the state of the iron oxide, and from white through

» Barrcll, Bull. Geol. Soc. Amer., vol. 2^, p. 4i6,fi9i2.

44 THE PERMO-CARBONIFEROUS RED BEDS OF

gray to black, according to the amount of carbon. But over the larger portion of
the delta the iron of the soil is more or less completely oxidized during the season
of dryness, and the corresponding colors — yellow, orange, red, or brown — are in
evidence. The ratio of these oxidized and deoxidized sediments varies with the
flatness of the delta and the character of the climate."

The conditions which permitted the deposition of the limonitic conglom-
erates did not long endure, for the beds are thin and there is a succeeding
thickness of 1 00 or more feet of red clay, with beds of red and gray sandstones.
As shown above, the red deposits can only mean regions and periods where
and when large quantities of ferric oxide were poured into bodies of water,
either quiet or disturbed, and of considerable size. That the bodies of water
were frequently local in character, and disturbed by currents either due to
rivers or winds, is shown by the lack of continuity and the cross-bedded
condition. The variations in the strike of the beds, sufficiently large to be
followed for any distance, is extreme. For instance, south of Dundee the
strike of a shaly sandstone is almost at right angles to the prevailing north-
east-southwest strike of the limestone beds, which are the most continuous
beds in the region and must be regarded as indicating the dominant strike
in the region. Along the outcrop of this sandstone the author has found
many fossils of land and swamp reptiles as if they had been drifted to this
particular bar or beach by definite currents. Above this layer there is a
loose, coarse, almost arkosic sandstone, and above that a mass of coarse
conglomerate which I believe to be what Gordon interprets as formed of
previously wave-washed and wave-broken fragments of clay. If it has been
formed as Gordon thinks, the action must have been very local, for the bed
is not traceable for any great distance. (Plate 9, figs, i and 2.)

There is a general suggestion in all the deposits of the Wichita of a
prevalent aridity; this comes from the highly oxidized condition of the
material, coupled with the lack of any quantity of vegetable remains. The
suggestion is borne out by the fact, noticeable throughout the series, of the
complete absence of any sulphides or other unoxidized or uncarbonated
minerals. The suggestion of local swamp or lagoon conditions given by the
presence of small quantities of blue or green clays and shales is more than
counterbalanced by the great preponderance of compounds high in oxygen,
by the absence of any black shales, and by the absence of any plant remains
other than a few impressions in the sandstones and clays. Moreover, I have
submitted some samples of the sand from these beds to Professor Sherzer,
of the Ypsilanti Normal College, who assures me that the grains have the
appearance presented by wind-blown sands. The frequent presence of copper
carbonate may point in a slightly different direction. Copper carbonate, as
azurite or malachite, frequently occurs in the form of nodules, or as coatings
upon fragments of petrified wood. It seems probable that the copper in the
waters (in what form we do not know) was reduced to the metallic state by
organic matter, and subsequently oxidized or carbonated. Thin veins of

xMORTH AMERICA AND THEIR VERTEBRATE FAUNA. 45

metallic copper have been found in the clays near Enid, Oklahoma. These
occurrences, however, may be due to mere incidents in a general history.^

EVIDENCE OF CLIMATIC CONDITIONS IN CLEAR FORK TIME.

To the west of the road running south from Dundee, approximately
along the east line of Baylor County, the beds above the Wichita show a
decided change in character. There is a much larger proportion of blue and
gray clays, the limestones appear, and there is a change in the character of
the conglomerates and coarse sandstones. The pebbles of the latter are more
quartzitic, or contain a larger proportion of fragments of igneous rocks.
Aside from the Hmestones, the beds retain the discontinuous character and
the pronounced cross-bedding.

The lowest limestone is impure, earthy, whitish on fresh fracture, but
weathering to a rusty brown on exposure. It is not over 6 to 8 inches in
thickness, and breaks up into small blocks which, because of its superior
resistance to the soft clays above and below, determine the presence of a
shelf or broad terrace on the south side of the Godlin Creek, south of Fulda
and Maybelle, which may be traced even to the Big Wichita, where the
blocks are larger. This hmestone, with marine fossils, clearly indicates the
extension of the sea over the region, probably an extension of the "Albany"
sea from the south. The invasion of this sea, with its fauna of marine
invertebrates, Myalina, Naticopsis, Nautilus, etc., was preceded by the depo-
sition of 6 to 8 feet of a light blue or white sandy clay, with a considerable
calcareous content, which is sharply defined from the red clay below and
the limestone above. The layer is fairly persistent, and is found just below
the hmestone wherever the latter occurs. The white clays do not weather
brown upon exposure, indicating a very small content of iron, if any. This
means one of two things: either the clays were deposited under conditions
which permitted a thorough leaching out of the iron, or they were derived
from a region in which there were no iron-bearing minerals. The latter
possibility seems the least plausible. In the first place, the origin of the
sediments must have been at a considerable distance — the Wichita Moun-
tains to the north or the precvirsors of the Rockies to the west. And certainly
the character of the rocks of the central igneous cores of these masses did
not fluctuate. It is far more probable that the sea of "Albany" time, ad-
vancing toward the north and west over the semiarid coast, did not reach
to the mountains, but did go far enough to produce a decided effect upon
the humidity, and so induced a heavier rainfall, and, consequently, a heavier
growth of vegetation. Plant remains have not been discovered at any point
very far east of the first outcrop of the limestones.'' The vertical movement

» Clark, Data of Geochemistry, 2d ed., p. 627; Haworth and Bennett, Bull. Geological Society Amer.,
vol. 12, 1900, p. 2; Schmitz, Trans. Amer. Institute Mining Engineers, vol. 26, 1896, p. loi. (Impregnations
of copper in fossil wood in the Texas Permian.)

'' See David White, The Character of the Fossil Plant Gigantopieris Schenk, and its Occurrence in
North America, Proc. U. S. Nat. Mus., vol. 41, 1912.
4

46 THE PERMO-CARBONIFEROUS RED BEDS OF

of the sea-level, or the land-level, need have been only very slight to have
produced a widespread transgression, and a reverse motion, equally slight,
would have excluded the waters. That the effect upon the climate was
equally short Hved is indicated by the fact that, while the underlying clays
are devoid of iron, the limestone above is spotted by ferric oxide and weathers
to a rusty brown.

The condition of the limestone is rather puzzling. From general consid-
erations it is supposed that the area of northern Texas, at least as far west
as the center of the Staked Plains, was a broad, fiat area of aggradation
crossed by large streams, a delta of the large size postulated by Barrell in
his discussion of the Paleozoic deposits of the Mississippi Valley, and that
this was normally more or less arid, its deposits freely exposed to the oxidizing
action of the air, and devoid of much vegetation. The advance of the
"Albany" sea inducing a greater humidity and plant growth on the land
ahead of it and a consequent increase in available CO, would have resulted
in the deoxidization and leaching out of the iron, resulting in the deposition
of the light-colored sandy clays. The further advance of the sea would have
continued the humid conditions, and we would find the light-colored clays
farther to the west and north, and the limestones which replaced them would
be free from ferric iron. Either of two explanations may be offered for the
presence of the ferric iron in the limestone: (i) The iron, leached from the
clays, leaving them white, may have been carried out to where limestone was
forming and there deposited as ferric iron; (2) the sea, whose western limits
we do not know, may have extended so far toward the land-masses of igneous
rocks that there was little of the coastal plain left, and there was no place
for the iron derived from the rocks to be deposited and then leached out
again before reaching the sea.

The first of these explanations seems the more probable of the two.
From all indications, the land, either to the north or the west of where the
alternations of white clay and limestone appear, was so remote that it is
improbable that the limestone forming sea could have approached near to
them, and if, as supposed, there was an increase in the humidity due to the
encroaching sea, the degradation of the rocks would not have resulted in
the formation of ferric oxide, for Russell has shown that this would occur
only when there is a considerable annual period of drought or relative dry-
ness in the region subject to degradation. On the other hand, the white
clays probably gave up their original ferric iron as the carbonate, under the
action of the CO, derived from the increased vegetation, and would be
redeposited as hematite in the Hmestone forming in a body of shallow water
where there was an abundance of oxygen.^

A third hypothesis might be considered: that the white clays were origin-
ally deposited as red clays with a considerable content of ferric iron, and that
the ferric iron was leached out at a much later period by the action of per-

M'^in Hise, Principles of Metamorphism, Monograph 47, U. S. Geological Survey, p. 844.

NORTH AMERICA AND THEIR VERTEBRATE FAUNA. 47

colating waters charged with CO;,. That some such action has frequently-
taken place in the Red Beds of Permian and Triassic age is very probable,
for the masses of red clay and shale are frequently streaked with green along
the line of larger or smaller cracks and as frequently mottled with green
spots where slowly moving waters may have encountered some slight excess
of carbonaceous material and so reduced the iron. In such cases, however,
the mottling and streaking are very pronounced and the action is easily
recognized. No trace of it can be seen in the white clay under discussion,
which is entirely free from any trace of ferric iron.

That each advance of the sea was short lived is shown by the thinness
of the limestones, and that the increase in humidity was due entirely to the
presence of the sea is shown by the fact that the deposits immediately above
the limestone layers are nonmarine red clays and shales.

Though the conditions outlined are typically shown on the south side
of Godlin Creek, they may also be observed in other places, to the north
along Hackberry Creek and in the breaks of the Big Wichita, i.e., wherever
the Beaverburk limestone shows. The same sequence is repeated several
times. In one place the clays below the limestone (the limestone in this
exact locality having been removed by erosion) are filled with plant remains,
Estheria, some remains of insects, and bones of small vertebrates.

It is notable that the red clays which lie between the layers of limestone
and the layer directly above the highest limestone are filled with hard concre-
tions of impure, nodular calcite, endless in variety of form and composition,
and the calcite has associated with it sand, mud, iron ore, etc.

It is safe to assume that between the limestone depositing stages of the
Clear Fork were periods of greater aridity, when the sea had withdrawn
and concentration of the waters was sufficient to induce a high calcium-
carbonate content, but not great enough to cause the deposit of calcium
sulphate, or salt, except locally, where restricted pools were evaporated to
the point of saturation. That the aridity did not progress to a point pro-
hibitive of life is shown by the frequent occurrence of vertebrate fossils in
the concretions. It seems probable to me that certain of the impure lime-
stone beds were, in part at least, deposited from concentrated waters without
the action of organisms, for many of them are devoid of marine fossils, and
in certain layers east of the Seymour- Vernon road, near the Big Wichita
River, the upper surface is marked by sun-cracks, a condition that could
only occur in an exposed and drying mass of mud.

Barrell" makes the following remarks about the formation of mud-cracks
in limestones:

"Mud cracldng in chemical sediments, that is, in limestones, must, however,
be distinguished in significance from the cracking in claystones. Limestones are
carried in solution and their development requires a comparative absence of sand
and clay, the mechanical deposits carried by rivers and by waves. The solutions

» Barrell, Amer. Jour. Sci., vol. 36, p. 438, 1913.

48 THE PERMO-CARBONIFEROUS RED BEDS OF

to have sufficient concentration may come from permanent water bodies, either
lakes or seas. The deposit, therefore, comes not from the direction of the land,
but from the direction of the sea. The cracking goes on between the extreme levels
of high and low water, and the slight shifting of level is not a tidal, but at least a
seasonal, phenomenon. Such mud-cracking of limestones is a playa phenomenon,
and, especially in certain earlier ages, when the lands were base-leveled and lay
awash with the sea, broad areas seem to have been at times marine playas. Marine
fossils, often of depauperated facies, occur sometimes in the mud-cracked limestones.
The nearest approach in the modern world is found, doubtless, in the Runn of
Cutch, an area of 10,000 square miles flooded by the sea for a part of the year,
during the period of onshore monsoon winds."

This evident sequence of changes in climate and deposits, together with
the change in the vertebrate life found in the beds, seems to me to be suffi-
cient evidence upon which to establish the separation of the Wichita beds
from the Clear Fork at just about the line originally drawn by Cummins.

Above the highest limestones, appearing at Seymour and on a line east
of north from that town to beyond the Big Wichita River, there is a con-
siderable thickness of red clays, sandstones, and conglomerate, including the
Wichita conglomerate. This means a return to the more stable and arid,
or semiarid, conditions characteristic of Wichita time. But the change in
climate was not a sudden one, for overlying the uppermost limestones there
are 25 to 30 feet of gray, blue-green, and purplish clays, most clearly seen
in their darker phases in the bluffs, where the Seymour- Vernon road crosses
the Big Wichita River. These beds give place horizontally to red clay in
places, and are overlain by red clay.

Above the first series of red clays with sandstones and shales, which lies
over the highest limestone, is the Wichita conglomerate, a deposit of consider-
able extent in the valleys of Indian and Coffee Creeks (plate 8, fig. 2) on the
north side of the Big Wichita River, and traceable over a much larger area,
if, as is probable, it is the same layer which occurs at Haskell, in Haskell
County. It is a hard, pebbly conglomerate, 6 inches to a foot in thickness,
and varying in color from dark to light, but being through much of its extent
a deep purplish-red, varying to a light green color, which is very noticeable.^
The lighter shade, a pale green, is the phase seen persistently southwest of
Seymour.

The origin of this conglomerate layer is difficult to conceive, occurring
between two highly oxidized layers, but itself low in ferric iron. Relatively
thin but very persistent, it presents the appearance of a quickly covered
sheet of flood deposited material. The possible assimiption of its formation
by the compound deltas of flooded rivers is negatived by the thinness and
uniform thickness of the deposit.

Above the Wichita conglomerate a heavy mass of sandstones forms the
capping layer on the .south of the Big Wichita River, but on the north side
the same sandstone is covered by a considerable thickness of clay and shaly

» Case, Bull. Amer. Mus. Nat. Hist., vol. xxiii, p. 662, 1907.

NORTH AMERICA AND THEIR VERTEBRATE FAUNA. 49

layers. The heavy sandstones are responsible for a change in the topography
west of a line approximately marked by the Seymour- Vernon road. At
Craddock's ranch, on the south side of the river, the lower hills east of the
road give place to sharp buttes and deep, steep-sided valleys. The same
topography is found a little farther west on the north side. The heavy
sandstones at Craddock's ranch are plainly due to the deposits of a strong
stream, or streams, from the west, as the cross-section of the bed of such a
stream is clearly shown at one place (plate 8, fig. i). Above this series of
sandstones, clays, and shales is a very thin calcareous layer, and in places
paper-thin red shales, with some insect tracks. This seems to be the highest
traceable layer of the Clear Fork. The sandy, easily eroded layers above
form a flat or rolling surface as far west as Sagerton, where the Double
Mountain beds appear.

SUMMARY OF CLIMATIC CONDITIONS.

From the above-assembled evidence it is apparent that the Wichita and
Clear Fork beds represent the accumulations of sediment on a wide, flat
delta or coastal plain, crossed by numerous streams, dotted by inclosed or
partly inclosed pools, subject, especially in Clear Fork time, to oscillations
of level slight in themselves, but sufficient on such a flat surface to produce
wide migrations of the strand-line. The surface was well exposed to the
air, and well above the level of ground-water, except during the infrequent
periods of submergence, and there were no great areas of stagnant water.

The climate was semiarid in general, but there were changes of short
period, apparently due to repeated incursions of the "Albany" sea, with a
quick response in the increased abundance of vegetable growth due to the
increased humidity.

The source of the material forming the beds of Texas and Oklahoma
which carry the vertebrate fossils was undoubtedly the Wichita Mountains
and adjacent elevated masses, and we can not doubt that they were much
larger in Permo-Carboniferous time than now.

The blue clays, white clays, and light-colored sandstones associated with
the Hmestones of the Clear Fork are similar to the red deposits in all respects
but the content of ferric oxide. The source of the material remained
unchanged, and there could have been no diminution in the available iron.
There is little evidence (a few beds of conglomerate) of any reworking of
the once-deposited material. The iron-free beds, or those with ferrous iron,
owe their condition to the removal or the reduction of the ferric iron derived
from the original rocks. The only available agent for this action would be
the carbon derived from the decay of a considerable amount of vegetable
matter. As has been repeatedly shown, carbon thus derived would exhaust
the available free oxygen, and even extract oxygen from oxides already
formed. The carbon dioxide thus formed would convert the iron into the
soluble carbonate, which would easily be leached out of the beds.

50 THE rERMO-CARBONIFEROUS RED BEDS OF

As shown above (p. 45; see also p. 104, below), the greatest number of
plant remains, and the greatest abundance of iron-free deposits, and deposits
with ferrous rather than ferric iron, occur closely associated with the Clear
Fork limestones. The series of limestones and associated light-colored clays
are separated by beds of red color, high in ferric oxide. This indicates a
decided fluctuation in the climate. The cause of this fluctuation is far from
apparent. In lack of a better explanation the variations in climate are
tentatively associated with the recurrent invasions of the sea from the south.
It is conceived that the dominant condition of the whole area, and a wide
surrounding region, was semiaridity, with a somewhat higher degree of
humidity on the highlands of the ancient Wichita Mountains. When the
seas spread in wide and shallow bodies over the flat land and reached far
toward the mountains, the waters of the lagoons, estuaries, and pools upon
the borders of the advancing sea were warmed, and a large quantity of water-
vapor rose in the air, but the relative humidity was not increased, since the
amount of water-vapor which may pass into the air with a rising temperature
is always greater than the amount actually evaporated. If, for some reason —
cyclonic or monsoonic effects, for instance — this air with its really large
content of water-vapor was drawn across the high land of the neighboring

Fig. 8. — Diagr.-im illustrating advance of the "Albany" sea over Wichita and Clear Fork
deposits, showing how the presence nf the water precedes the deposits and possibly
affected precipitation on land from which deposits were derived.

Wichita Mountains, the cooling of the air would cause an abundant precipi-
tation on the slopes. This water would pass out upon the flats adjacent
to the ocean border, increasing the volume of the streams, raising the water-
table, and inducing a much greater plant growth. The decay of this vege-
tation would furnish the carbon necessary to reduce the ferric oxide present,
or would exhaust the free oxygen, which would otherwise result in the for-
mation of ferric oxide. The carbon dioxide fonned would leach out the iron
already deposited, and white or gray iron-free beds would result, or beds with
ferrous iron, green, blue, or purple.

These conditions would exist in front of the advancing sea, and the iron-
free clays would be below the limestones, as they always are. When the
reverse change occurred, following the retreat of the sea, the local evaporation
woiild decrease, the supply of moisture decrease, the vegetation fail, and
red-colored rocks would again predominate.

If, as conceived, the oscillations of level were due to tilting, with the
axis of tilting south of the Wichita Mountains, the depression of the plain
would be accompanied by an elevation of the mountains, accentuating the
conditions described; but this movement was never very great in either
direction.

NORTH AMERICA AND THEIR VERTEBRATE FAUNA. 51

STRATIGRAPHY OF THE RED BEDS IN OKLAHOMA.

North of the breaks of the Big Wichita the surface of the country is
rolling and grass-covered, and there is very little exposure of the rocks or clays,
but it is evident that the same formations exposed farther south are continued.
Cummins found Wichita fossils {Cricolits, Edapliosaurjis, and Dinictrodoii)
near where the road leading from old Fort Augur to Fort Sill crosses Deep
Red River. This is his Indian Territory locality. The author found frag-
ments of Edaphosaiinis spines near Emerson and fragments of Eryops and
Dimctrodon near Randlett, on the south side of Deep Red Run or River.
This last locality is several miles east of where Cummins got his fossils.
The surface of the breaks at the last locality shows mostly a deep-red clay,
with irregular patches of conglomerate (carrying the bones) and irregular
sandstone lenses, with much coarse concretionary material. The top layer
is 2 to 3 feet of shaly white sandstone. Both the fossils and the character
of the beds would tend to confirm Cummins's conclusion that these beds
are of Wichita age. Williston, traversing the same region somewhat farther
north, found a few fragments of bones {Diplocauhis, etc.) in isolated patches.

These localities arc well within the area marked by Gould "^ as "red beds
of uncertain relationship," surrounding the Wichita Mountains, and we
may be certain that the Wichita and Clear Fork extend at least as far north
as the fossils have been found, and probably include most of the area marked
as uncertain on Gould's map. Immediately surrounding the mountains the
land is more rolling and unbroken, and exposures are scarce. The exact
age of the sediments near the mountains remains undemonstrated, but
Gould describes them in terms that might well be applied to the Wichita
or Clear Fork formation in Texas : ^

" Lawton Area. — One of the areas referred to includes the country surrounding
the Wichita Mountains on all sides, occupying practically all of Comanche and
Kiowa Counties, besides eastern Greer, southern Washita, and southwestern Caddo
Counties. The deposits of the Greer formation surround the Wichita Mountains
at a distance of from 20 to 30 miles, on all sides except on the south. It is between
these Greer outcrops and the mountains that the rocks referred to occur. They
consist chiefly of red clay shales, with a few ledges of sandstone and dolomite, and
in that regard correspond to the Woodward. Like the Woodward, also, these
beds appear to underlie the Greer. Until the correlation of the rocks with the Texas
beds south of the Red River has been worked out, however, the exact relation of
the red beds of this area must remain a matter of doulat."

Between the beds srurounding the mountains, which are so evidently
of Clear Fork and Wichita age, and the Enid of Oklahoma, which carries
the same fossils, the Greer and the Woodward are exposed in a long strip
running northwest-southeast. The Greer has been correlated with the
Double Mountain formation, and the Woodward with the upper part of

" Gould, Map, U. S. Geological Survey, Water Supply and Irrigation Paper No. 148.
^ Gould, Ibid., p. 73.

52 THE PERMO-CARBONIFEROUS RED BEDS OF

the Clear Fork,'' but no vertebrate fossils have been found in either one.
Unfortunately we have no record of just what becomes of the Greer and the
Woodward to the southeast. Gould's map ceases before the end of the forma-
tions is reached. But we know that the Wreford limestone has been traced
south to the western side of the Arbuckle Mountains as the Payne sand-
stone,'' and that the Cisco begins in Texas just east of Henrietta, and that
both of these shade into red beds on the west. The question rises whether
the Enid is to be regarded as a continuation of the Wichita and Clear Fork
as represented by the Red Beds around the Wichita Mountains, or whether
it is possible that the 800 feet," more or less, of the Greer and Woodward,
is to be regarded as completely dividing the two formations, instead of ex-
tending over them as an embaynient from the northwest. Fossils from the
Enid have not been found south of Mulhall, in Logan County, and this
leaves quite a distance between the areas whose age has been determined,
but, as shown below (see table, p. 96), the vertebrate fossils from Orlando,
Pond Creek, and McCann's Quarry are very similar to, or identical with,
those from the Texas localities.

Descriptions of the Enid and Woodward have been given by Gould, "^
and are as follows:

"The Enid formation includes all the rocks of the Red Beds from the base of
the Permian to the lowermost of the g;y'psum ledges on the eastern slope of the g\'p-
sum hills. The top of this formation, however, is not a plane, since the g}'psum beds,
which mark its uppermost limits, are found to be more or less lenticular when traced
for long distances. The Enid comprises all of the Harper, Salt Plain, and Cedar
Hills members, and the greater part of the Flowerpot member of Cragin's first
paper, and the Kingfisher and Glass Mountain formations of his second paper. It
is named from the county-seat of Garfield County.

' ' The Enid outcrops over a larger area than any other formation of the Permian
in the Oklahoma, and is exposed extensively in adjoining States. In Kansas it out-
crops over parts of Sumner, Kingman, Reno, Barber, and Comanche Counties, and
all of Harper County. In Oklahoma it is found in the western parts of Kay, Noble,
Payne, Logan, Oklahoma, and Cleveland, parts of Woods, Woodward, Blaine, and
Canadian, and all of Kingfisher, Garfield, and Grant Covmties. It also extends into
the Chickasaw Nation.

"The Enid formation consists chiefly of brick-red clay shales, with some inter-
bedded ledges of red and whitish sandstone. It occurs in two general areas, which
may be distinguished on lithological grounds as follows : An eastern area, in which
there are a few inconspicuous ledges of sandstone, and a western area, in which
the sandstones are mostly wanting. In the present state of knowledge, it is impos-
sible to draw an accurate line of separation between these two areas, and for this
reason the strata in them are not defined as separate members.

» Schuchert, Paleogeography of North America, p. 558; Gould, U. S. Geological Survey, Water Supply
and Irrigation Paper No. 155, p. 17.

'' Kirk, Third Biennial Report State Geologist Oklahoma, 1904; Gould, Ohern, and Hutchinson, State
University Oklahoma Research Bull. No. 3, map.

• Gould, U. S. Geological Survey, Water Supply and Irrigation Paper No. 148, p. 40.

■^ Gould, Ibid., pp. 39-52.

NORTH AMERICA AND THEIR VERTEBRATE FAUNA. 53

"The eastern area of the Enid formation is triangular, and occupies several
counties in the central part of the Territorj-, in which there is little hard rock of
any kind. Its eastern boundary is approximately along a line from Blackwell to
Norman, and its western limit is along a line from Alva to El Reno. It includes east-
ern Blaine, Canadian, and Woods Counties, all of Grant, Garfield, and Kingfisher,
and the western parts of Kay, Logan, Noble, Oklahoma, and Cleveland Counties.

"Throughout this area the soil is red, except where later depcsits cover the
uplands, or among the sandhills north of some of the streams. Red clays and occa-
sional ledges of thin sandstone outcrop along the bluffs of a few streams. These
sandstone ledges, however, are of comparatively little economic value, being gener-
ally too soft for building purposes. Quarries occur near Nardin, Kingfisher, Hen-
nessey, and Luella. In the general absence of building stone, foundations for houses
are usually made of brick, and artificial stone may come into use extensively.

"The rocks of the western area of the Enid consist chiefly of red clay shale, some
inconspicuous ledges of soft sandstone, and occasional bands of whitish or greenish
shales, which vary from one inch to several feet in thickness. The upper strata are
in places highly gypsiferous, and at some localities brine springs issue from them.
No attempt is made to separate the eastern and western areas of the Enid formation,
except to state that they are sometimes separable locally a few miles east of the
base of the Gypsum Hills.

"The Enid formation is in most places strongly impregnated with mineral salts,
particularly common salt and g>^psum. In many localities the water from the wells
is unfit for drinking, and the people are obliged to use cistern water.

"In the western area, along the base of the Gypsum Hills, salt measures are
prominent. The Little Salt Plain, in northern Woodward County, near the Kansas
Line, and Big Salt Plain, in the northeastern part of the same county, are both
located in the Cimarron Channel, while the Salt Creek Plain, in north-central
Blaine County, is on a tributar>' of the same river. At the Salt Creek Plain some
of the most typical saline springs in the Territory may be seen. In several canyons
at the head of Salt Creek are exposures of a grayish-red, mottled, saliferous sand-
stone. This sandstone is often distinctly cross-bedded, and appears to have been
tilted; from it issue numerous springs of strong brine. So far as is known, this
sandstone is not found elsewhere in the region, and it seems to be a local phase of
the clay-shale formation. It is possible, however, that these sandstones are not
themselves salt-bearing, but are merely porous strata through which brines from
some deep-seated source reach the surface. The water from the springs issuing
from the various canyons forms rills, which, in turn, unite to form the headwaters
of Salt Creek.

"Above the level of the Salt Plains, and below the g>-psum ledges, there inter-
vene 150 or 200 feet of red clay shale, which is interspersed with bands of whitish,
greenish, and bluish clay, and local thin ledges of g>'psum.

"The very soft material of which this shale is composed renders it particularly
susceptible to the action of the weathering, and the entire thickness is characterized
by marked erosion forms. Wherever the cap of gypsum has been removed over any
considerable area, or for any great length of time, these shales have been worn
away. Perhaps the most common erosion form is that of cones of red clay cut by
deep and uneven gullies — regular bad lands structure. Not infrequently rows of
these cones are arranged palisade-like along the summit of a fast-disappearing ridge,
into which gullies are eating their way. In the Glass Mountains, for instance, the
slope of the bluffs below the gypsum ledges is much cut by erosion. The action of
the water has produced a great variety of unusual forms. Small buttes and but-

54 THE PERMO-CARBONIFEROUS RED BEDS OF

tresses, cones and minarets, pinnacles and peaks, shoulders and ridges, domes,
towers, chimneys, gullies, ravines, and all sorts of fantastic shapes have been carved
by erosion from the blood-red shales along the slope of the bluffs.

"The face of the blufifs is frequently covered with fragments of gypsum, either
in the form of plates of transparent sclenite or in the form of concretionary masses.
The selcnite is usually found in scams running diagonally through the clay, and the
crystals weather out and reflect the sun from thousands of points, making the slopes
appear to be covered with glass, whence the name, Glass Mountains.

"The thickness of the Enid formation is unknown, but it is probably not less
than 1,200 feet, and may reach 1,500 feet. The well at Fort Reno was started at
about the same level as the top of this formation and reached a depth of 1,370 feet,
the drill stopping in red clay. It is possible, however, that this well passed through
the Permian rocks into beds of Pennsylvanian age beneath. At Spencer, 12 miles
east of Oklahoma City, a well passed out of the Red Beds at a depth of 1,550 feet.
The greater part of this thickness, however, was in Pennsylvanian rocks.

"Woodward Formation. — ^Above the Blaine are approximately 300 feet of rocks,
consisting chiefly of shales, sandstones, and dolomites, and distinguished from the
formations above and below by the prominence of dolomites and the absence of
gypsum. The formation includes all the rocks between the two conspicuous gypsum
horizons, the Blaine and the Greer, and in general it may be divided into three
members — the Dog Creek, the Whitehorse, and the Day Creek — which were all
recognized and named by Professor Cragin from localities in Kansas, except that
his term Red Bluff was preoccupied, and for it the name Whitehorse has been sub-
stituted. For the formation as a whole, from the top of the Shinier g^-psum to the
base of the Chancy gypsum, the name Woodward is proposed, from the county in
Oklahoma, where the strata are well represented.

"Dog Creek Shales Member. — The Dog Creek member is composed mainly of
clays, containing occasional thin ledges of magnesian limestone, which in places
grade into a fair quality of dolomite.

"The ledges, however, are usually thin and rarely sufficiently conspicuous to be
worthy of more than a passing notice. Professor Cragin's original description of
this member is as follows :

"The Dog Creek * * * consists of some 30 feet, or locally o£ a less or greater thickness,
of dull red argillaceous shales, with lamina; in the basal part and one or two ledges of
unevenly lithificd dolomite in the upper. The color of these shales resembles that which
prevails in most of the divisions below rather than of the terranes above Dog Creek."

"In his second paper he modifies his description in this way:
" In central Oklahoma it is a great dolomite fonnation, laminated dolomite occup>-ing a
considerable part of the thickness."

' ' In his second paper he suggests that the name Dog Creek be changed to Stony
Hills. The writer agrees that the name Dog Creek is, perhaps, not the best that
could be used, but in view of the fact that the dolomites which make up the Stony
Hills in eastern Blaine County belong to the Blaine formation, and do not belong
to the Dog Creek, there seems to be no good reason for using the name Stony Hills
to designate this member.

"Studies made during the last 3 years have demonstrated that in many parts
of Oklahoma the thickness of the Dog Creek is much greater than that given by
Professor Cragin. Near Quinlan, in eastern Woodward County, the aneroid read-
ings indicate 225 feet as the thickness of these beds, measured from the top of the
underlying gypsums of the Blaine formation to the sandstones of the next higher

NORTH AMERICA AND THEIR VERTEBRATE FAUNA. 55

formation of this member, the Whitehorse, and in a number of localities 150 and
17s feet were recorded. Exposures are common along the top of the Gypsum Hills
from Canadian County to the Kansas line and beyond.

"Whitehorse Sandstone Member. — The Whitehorse sandstone was also described
(under the name of Red Bluff sandstone) by Professor Cragin, in his first paper,
as follows :

"This fonnation consists of some 175 or 200 feet of light red sandstones and shales.

* * * Viewed as a whole it is very irregularly stratified, being in some cases considerably
inclined, in others curved, and this oblique and irregular bedding, being on a much larger
scale than that of the ordinary cross-beddings, at first glance gi\'es the impression of dips,
anticlines, synclines, etc., that have been ]iroduccd by lateral ])rcssure; the dips, however,
being in various directions. * * * The Red Bluff Beds exhibit the most intense coloration
of any of the rocks of the series. When the outcrops are wet with recent rains their vividness
of color is still greater, and the contrasts of their almost vcnnilion redness with other colors
of the landscape are most striking. Spots and streaks of bluish or greenish gray sometimes
occur in these rocks, lout not to nearly so great an extent as in the lower beds. The sand-
stones of the Red Bluffs are generally too friable for building stone, but in some instances
selected portions have proved hard enough for such use, and arc fairly durable."

"In Oklahoma the Whitehorse member often weathers into conspicuous buttes
and mesas. For instance, in eastern Woodward and western Woods Counties a row
of these buttes, which rise 100 to 200 feet above the surrounding country, extends
from the vicinity of Whitehorse Springs, whence the name, southwest across the
Cimarron, to the high divides beyond. To some of these buttes characteristic
names have been given, as Lone Butte, Potato Hill, Watersign Hill, Wild Cat Butte,
and the like. The noted Red Hill between Watonga and Geary, in southern Blaine
County, is composed chiefly of the Whitehorse formation. South of South Canadian
River this sandstone thickens, and on weathering often forms conspicuous bluffs,
such as the famous Caddo County Buttes, southwest of Bridgeport. The White-
horse sandstone is exposed along the Washita from near Chikasha, Indian Territory,
westward, and in the vicinity of Anadarko it forms bold bluffs both north and .south
of the river, and extends as far west as Mountain View. Ledges which probably
belong to the same general horizon outcrop north of the Wichita Moimtains in the
vicinity of Hobart and Harrison, and it is not impossible that further studies may
demonstrate that the .same beds extend under the upper gypsums across Greer
County.

"Day Creek Dolomite. — Resting upon the upper part of the Whitehorse sand-
stone in Kansas and Oklahoma is a conspicuous ledge of hard white dolomite,
first described by Professor Cragin from exposures in southern Kansas, as follows :

"Upon the latest of the Red Bluff rests a persistent stratum of dolomite, varying in
thickness from less than a foot to 5 feet or more. * * * It is a true dolomite, containing
with the carbonate of lime an equal or even greater percentage of carbonate of magnesia.

* * * Though not of great thickness, it is an important member of the upper Pcmiian of
southern Kansas and northern Oklahoma, owing to its persistence, which makes it a con-
venient horizon of reference. * * * The stone is nearly white in fresh fracture, weathering
gray, and often has streaked and gnarly grain rcsemljling that of fossil wood. * * * Its
cherty hardness and fracture are not due to the presence of silica, as one is tempted to infer,
but are characters belonging to it as a dolomite. It is a durable building stone."

"In his second paper on the Permian rocks, in describing a typical Oklahoma
locality, Professor Cragin says:

"The brow of the Red Hills near Watonga, Oklahoma, is capped with the Day Creek
dolomite, which here presents itself a compact stratum of gra3^ somewhat pinkish or reddish
tinged, cherty, hard rock, little different from the typical ledge that skirts the flanks of
Mount Lookout, in Clark County, Kansas. The stratum here has a thickness of 3 feet."

THE PERMO-CARBONIFEROUS RED BEDS OF

"The line of outcrop of the Day Creek in Oklahoma is not continuous. Never-
theless it is found in numerous localities, and on account of its distinctive lithological
appearance it is always easily recognizable. It is displayed on many of the hills of
Woodward County, not only north of the Cimarron, but also between the Cimarron
and the North Canadian, and south of the latter stream. In Blaine County it
forms the caps of a number of the prominent hills, notably the Red Hills between
Geery and Watonga. South of the South Canadian River,
in Caddo County, the dolomite covers the Whitehorse
Buttes southwest of Bridgeport, and outcrops southwest-
ward as far as the headwaters of Cobb Creek and on the
west side of the creek past Colony. In the vicinity of
Mountain View, in the valley of Washita River, a ledge of
dolomite appears at the same general level as that occu-
pied by Day Creek, and another dolomite ledge in the hills
north of Harrison may provisionally be referred to this
horizon."

In a recent paper Beede •'' states as to the eastern
outcrop of the Neva limestone in Oklahoma which
he regards as marking the Permian horizon :

"So far as the evidence has been worked out it seems
necessary to place the base of the lower Permian either
at the base of the Elmdale formation, or, at the highest,
at the top of the Neva limestone." (p. 21.)

This is somewhat lower than the Cottonwood
Umestone which has been rather generally regarded
as marking the lower line of the Permian. Beede's
selection of this bed as marking the line between the
Pennsylvanian and the Permian is based upon the
faunal changes shown by the invertebrates. A de-
tailed discussion of the stratigraphy and sections
shown along the outcrop of the Neva limestone
forms the first part of the paper. The accompany-
ing map shows the outcrop of the limestone, mark-
ing, according to Beede, the eastern limit of the Permian in Oklahoma

Fig. 9. — Map of a portion of
central Oklahoma from
Kansas to Texas showing
the approximate eastern
limit of Permian rocks.
(After Beede.)

STRATIGRAPHY OF THE RED BEDS IN KANSAS.

Beyond the Oklahoma line, vertebrate remains have been found only in
Cowley County, Kansas, where, about 5 miles northeast of Maple City, a few
bones were discovered in the excavation of a well, and forwarded by Professor
Gould to Dr. Williston, who determined them as Permo-Carboniferous in age.''
Adams provisionally identifies the horizon of these bones as the Garrison."-'

» Beede, Oklahoma Geological Survey, Bulletin 121, 19 14. (The Neva Limestone in northern Okla-
homa, with remarks upon the correlation of the vertebrate fossil beds of the State. Eastern outcrop of the
Permian red beds in Oklahoma, with a discussion of the lithologic and color changes.)

iJ Williston, Kansas University Quart., vol. vi, No. I, p. 53.

■■Adams, Bull. U. S. Geological Survey No. 211, p. 72, 1903.

NORTH AMERICA AND THEIR VERTEBRATE FAUNA. 57

"Near the southern border of Kansas, in Cowley County, at a place about s
miles northeast of Maple City, some vertebrate remains were found in the shale
thrown out in digging a well. These were collected by Mr. C. N. Gould, and sent
to Dr. Williston, who identified the bones generically, and considered them as indi-
cating the Permian. The horizon in which these bones were found has been identi-
fied as the Garrison formation, although the correlation rests necessarily upon rather
meager evidence, since the distance from the type locality is considerable and the
invertebrate fossils have not been studied critically enough to admit of accurate
identification of horizons.

"In northeastern Oklahoma, in the area of the so-called Red Beds, there is a
locality which has yielded Permian vertebrate remains. The material has come
from two places: one known as McCann's Quarry, 5 miles southeast of Nardin, in
Kay County, the other 2 miles northeast of Orlando. The material has been studied
by Dr. Williston, who has found that it represents characteristic Permian forms,
such as have been reported from Texas. The stratigraphic position of the verte-
brates from near Nardin and Orlando has not been definitely determined. They
occur to the southwest of the southern extension of the so-called Permian lime-
stones of the Kansas section, but no horizon has been traced connecting the locality
with the Kansas section.

' ' The identification of the Permian in the western interior of the United States
for a long time rested upon the occurrence of reptilian remains, such as were first
described by Cope from the Red Beds of Texas. The occurrence in Kansas and
Oklahoma of the same genera which are found in Texas makes it possible to corre-
late the formations tentatively. The material in the Kansas section is meager. No
doubt more will be found, and possibly Permian forms occur, at lower horizons than
the Garrison formation."

The Garrison lies below^ the Wref ord , and is given by Adams as 1 40 feet thick .

There is, in the possible relation of the Red Beds around the Wichita
Mountains to those of the Enid formation, the suggestion that the gradual
change of the Hmestones into red shales and sandstones began at a lower
level in the north (Kansas and Oklahoma) than it did in the south (Texas).
The fossils from Kansas are perhaps a little closer to those of Illinois than
they are to those of Texas, but the number of forms recovered is so small
that any conclusion drawn from them is at best very uncertain. The fossils
from Oklahoma are very close to those of Texas, and do not in themselves
warrant the suggestion that the beds are lower.

If we examine the map of the Permian in Schuchert's Paleogeography of
North America, and also Ulrich's table of submergences,'' we note the persis-
tence of a trough from the Gulf of Mexico which extended northwest around
Ozarkia, and over a portion of the Ouachita uplift. It is probable that the
limestones on the eastern side of the Red Beds were deposited in this extension
of the sea, and that the red sediments came from the west and the southwest.
It is practically certain that this gulf was fairly narrow, and there may have
been red beds on the east derived from the land in southwestern Missouri, but
if such beds existed all traces of them have been removed by erosion.

While most of the animals of the Texas region must be supposed to have in-
habited the uplands and shores of the western and southern localities, it is alto-

• Ulrich, Bull. Geol. Soc. Amer., vol. 22, No. 3, pp. 346, 347.

THE PERMO-CARBUNIFEROUS RED BEDS OF

gether possible that they originated in migrations from the east around the
northern side of Ozarkia, and that they may have reached the regions in
Kansas earhcr than they did the more southern regions, for we know that
there was a gradual and progressive elimination of the waters on the surface
of the continent from the east toward the west during the Pennsylvanian
and the Permo-Carboniferous.

GUADALUPE

MOUNTAINS

STAKED
PLA I No

IANOLE-
N5A3

WOOO'^ARD

^^'ELL'^tGTON
ARION

EXTENSION OF THE RED BEDS TO THE WEST BEYOND THE LIMITS OF VERTEBRATE

FOSSILS IN THE TEXAS PROVINCE.

Cummins, in his maps of the Permian of Texas, has drawn the limits
reaching far to the south of the bone-bearing beds, as noted above (p. 6),
and west to the Staked Plains. Beede ^ has maintained that the Red Beds
on the east side of the Pecos Valley are equivalent
to, or are a continuation of, the upper beds of Permo-
Carboniferous age of Texas and Oklahoma, and this
is in confirmation of Cummins's earlier statements.

He shows that Guadakipian limestones shade
north and east into red beds which are the same as
those to the east, and argues that the conditions in-
dicated by these beds isolated the invertebrate favma
of the Pecos Valley region from that shown in the
Whitehorse formation in Oklahoma and the eastern
part of the Panhandle of Texas.

"If the conclusions reached above are correct"^ it
leads at once to the correlation of the Kansas and Guad-
alupian sections. If we iise the Whitehorse sandstone,
probably the equivalent of the beds in contact with the
Guadalupian limestone near Carlsbad, as a common
basis of correlation of the two sections, we attain the
result shown in the accompanying diagram [fig. lo].
Disregarding their actual f aunal relationships and com-
paring them as to their thickness, the strata of the two
sections compare as follows, the figures of the Guada-
lupian rocks being approximations:

"In southern New Mexico we have some 4,500 feet
of the Guadalupian series, composed of 2,100 feet of

Capitan and overlying limestones, and 2,400 feet of the Delaware Mountain for-
mation, composed of limestones and sandstones overlying 5,000 feet of Hueco lime-
stones. Beginning at the same horizon in Kansas, we have the remainder of the
Red Beds, the fighter Permian and the Pennsylvanian, aggregating about 4,500 feet
of strata, composed of limestone shales and sandstone. So far as mere thickness is
concerned, it leaves the base of the Delaware Mountain formation about on the level
with the Cherokee shales (as exhibited in Kansas). The horizon of the base of the
Delaware Mountain formation in the Kansas section, interpreted upon its fauna,
or actual time equivalency, may be a very different matter. The base of the
Capitan falls near the bottom of the Elmdale formation stratigraphically, which is

RtD BED5

TRtASSiC TRiASiiiC
v^HiTEHORSEBEOS

r :. F 1 T i N

---?---

DELAWARt
MOUNTAIN

H L' E C 0

MISSISSIPPIAN

Fig. 10. — Diagram showing rela-
tion of beds in Guadaloupe
Mountains to those in Te.\as
and Kansas. (After Beede.)

" Beede, Amer. Jour. Sci., vol. xxx, Aug. igio, p.
^ Beede, Ibid.

131-

NORTH AMERICA AND THEIR VERTEBRATE FAUNA.

probably not far from its correct faimal correlation as well. The paleontological
comiDarisons are yet to be worked out. The unconformity above the Capitan lime-
stone, and locally even in the Delaware VIountain formation, the Capitan having
been carried away, is not taken into account in making these comparisons." It is
probable that it diminishes rapidly to the northward, where it is of less consequence.
"One of the most interesting features of the Guadalupian fauna is its isolation.
As has been stated by Girty, the fauna is a unique one, and, as a unit, is now known
from no other part of the western hemisphere. At first thought it seems peculiar

Fig. II. — Map showing Beedc's idea of the Palcogcography of the Red Beds in the southern part
of the Plain Province. (After Beede.)

that more of its members were not distributed over the adjacent regions where con-
temporaneous strata occur. Their absence in such rocks has been a serious difficulty
in any attempt to correlate them with other American faunas.

"In the first place, the lower Red Beds lying to the eastward, with which the
Guadalupian limestones are probably contemporaneous, are believed by some to be
to a considerable extent of subaerial origin, while the temporary seas that occupied
portions of it from time to time were too concentrated in salt content for normal

" Richardson, University Mineral Survey Texas, Bull. 9, pp. 43, 44, 1904.

6o THE PERMO-CARBONIFEROUS RED BEDS OF

marine faunas. So far as my collecting in the typical Capitan limestone goes, the
fossils were abundant only in the purer limestones, and were very rare, or wanting
in what appeared to be tlie dolomitic portions of it. These limestones occur in the
Apache Mountains and at Guadalupe Point, but appear to be wanting, as does the
fauna, north of the Texas line; the only exceptions noted were Fusulina clongata
and one or two other species in Dog Canyon and Sitting Bull Canyon. From this
it will be seen that the fauna was closed off on the north by untoward conditions
and on the east by the red bed sedimentation, which constituted a barrier. No
other barrier is known.

"Two other considerations must be taken into account. First, that the Permian
facies of this fauna may be an abnormally early precursor of the Permian faunas
developed in an isolated basin. Such an occurrence of Permian forms is known in
Kansas well down in deposits of Pennsylvanian age. However, the variety and
richness of the Guadalupian fauna, which possess such a young appearance, seem
to me to argue against this hypothesis. Second, the other possibility is that the
fauna is no older than it appears, and that it developed normally with little outside
connection, as did the Kansas Permian fauna. The same features as before would
have controlled its isolation. Much of the Red Beds being almost a land surface a
considerable part of the time — if we accept the subaerial origin of a large part of
the deposits — aggradation may have but slightly overbalanced degradation, and
they may have accumulated slowly for that class of sediments. Thus, though dis-
turbances raised the southern part of the Guadalupe limestones above sea-level, and
permitted their partial removal and the subsequent deposition of the upper Red
Beds upon the eroded surface, the fauna may well have been an early Permian
fauna. Until further data are at hand I am much inclined to this latter hypothesis.
The fact that several hundred feet of the Kansas Permian deposits grade off into
typical red beds in a very short distance in Oklahoma is .suggestive of possible con-
ditions east of the Guadalupes. If such were the case, we would expect the Guada-
lupian faunas to cease as abruptly upon the strata changing to the Red Beds as
the Kansas faunas do upon entering the Oklahoma Red Beds.

"At the same time, owing to the very nature of the origin of the Red Beds,
their extreme southwestern part may have been deposited slightly later than the
main mass farther to the north and east. However, this is regarded more in the
nature of a possibility than a probability.

"The accompanying map [fig. ii] indicates the probable relationship of the
marine areas during Council Grove-Chase and Guadalupian rime in the immediate
area under consideration. No attempt is made to show the full extent of deposits
laid down at this time. The full lines indicate marine conditions and the lines alter-
nating with stippled ones continental-marine deposition. The extent to which the
two factors contributed to the formation of the Red Beds is at present unknown.
The area of marine conditions in Central Texas is to represent the Albany sea."

EVIDENCE OF A BARRIER OR INTERRUPTION OF DEPOSITION OF RED BEDS TO THE WEST.

There is some considerable probability in this suggestion, but the author,
traversing the region from Tucumcari to Las Vegas, New Mexico, in the
summer of 191 2, found no trace of red beds which could be referred to the
Permo-Carboniferous. The lowest red beds encountered yielded Phytosaur
remains and Unio, clear evidence of their Triassic age.^

« Case, Jour. Geol., vol. 22, No. 3, April-May 1914. In the paper cited the author gives details of the
stratigraphy of this region (see plates 11-13).

NORTH AMERICA AND THEIR VERTEBRATE FAUNA. 6l

The Red Beds were followed from their eastern limit in Oklahoma to
their final appearance as vertical beds on the eastern side of the Rocky
Movmtains, and kept continuously in sight, except where they disappeared
beneath the Dakota Cretaceous, in the mesa just east of Las Vegas, and under
the Tertiary of the Staked Plains. The last trace of the Permo-Carboniferous
was seen on the east side of the Staked Plains, near Spurr, in Dickens County
(plate 13, fig. i) ; on the west side all the red beds along the route followed
are Triassic (plates 11, 12, 13). At Las Vegas Hot Springs the beds are
vertical (plate 12, fag. 3), or nearly so, and the conditions are extremely
unfavorable for seeking vertebrate fossils, but after a half-day's careful
search a single imperfect tooth of a Triassic dinosaur was found in a bed
of conglomerate. This tooth was discovered near the middle of the section
and demonstrates that the upper half, or more, of the exposure is Triassic. As
the beds below are strikingly similar to the one in which the tooth was found,
it is apparent that if any Permo-Carboniferous appears on the side of the
mountains it is very thin. I am inclined to the belief that the Permo-Carbon-
iferous beds end somewhere beneath the Triassic in eastern New Mexico.

Schuchert, in his paleogeographic map of the Permian, shows the Guada-
lupian region as distinctly separated from the Texas-Oklahoma-Kansas re-
gion. Beede believes in the presence of a barrier to marine life, but assumes
the continuance of red-bed deposition.'' Schuchert, quoting Girty, asserts
the independence of the Hueconian and Guadalupian faunas and later
deposits of the Cordilleran sea.^ Girty says:

"Through the west, however, these faunas will probably prove to have ex-
tended widely. The Hueco will perhaps prove to be the same as the Aubrey forma-
tion of northern Arizona."

Schuchert himself says : "

"The writer believes that the Aubrey faunas are younger than those of the
Hermosa, but still Pennsylvanian, and of a distinct faunal province — that is, of the
western Cordilleran basin."

Schuchert again quotes from Girty: ^

"The Mississippian faunas, together with the earlier Pennsylvanian ones, ap-
pear to be absent [in the Trans-Pecos region]. The Hueconian fauna is widely dis-
tributed over the West, ranging, indeed, into Alaska, while it is even recognizable in
Asia and eastern Europe. Most of the occurrences of Carboniferous in the West can
be referred to this series, though some of them present more or less distinct facies."

And again:

' ' The life of the Guadalupian is quite unlike the faunas of eastern North America,
and almost equally unUke most of those of the West. The nearest are probably those
of the Salt Range and Himalaya, in India, and the Fusulina limestone of Palermo."

These quotations from Schuchert and Girty seem to confirm the author's
opinion that the Permo-Carboniferous does not occur on the western side
of the Staked Plains, at least in the latitude of Las Vegas, in Texas and
eastern New Mexico.

" Beede, Amer. Jour. Sci., vol. xxx, Aug., igio, p. 138. ' Loc. cit., p. 574.

'' Schuchert, Paleogeography of North America, p. 573. '' Girty, Jour. Geol., 1909, p. 311.

CHAPTER II.

DESCRIPTION OF THE NORTHERN PORTION OF THE PLAINS PROVINCE
AND THE EASTERN EDGE OF THE ROCKY MOUNTAINS.

(Sccj plates 2 and 3, opposite pages 64 and 66.)

Beede'' has shown that the hmestone which m southern Kansas can be
traced into the Red Beds of Oklahoma can be followed north through Kansas
and even into Nebraska. Its western extension in these States is covered by
Cretaceous and Tertiary deposits. Barbour '^ says that the Red Beds are
lacking in Nebraska, though the Permian limestone appears in the eastern
part. This means that they do not appear on the surface and have not been
reported in well records.

Darton," in his sections across Nebraska, sviggests the disappearance of
the Red Beds to the west by playing out, but this is only a suggestion.

The age of the Red Beds in Dakota, Wyoming, and Colorado is still
uncertain. The upper portion is without doubt Triassic, but there is good
reason to believe that the lower parts may be Permo-Carboniferous. In the
following pages evidence is given in some detail to show that the Permo-
Carbonifcrous portion of these beds may be a part of the area of deposition
in which the vertebrate remains occur in Texas, Oklahoma, and Kansas, and
that the two regions are connected by red beds continuous with the western
edge of the limestones of the same age which can be traced through Kansas,
Nebraska, and eastern South Dakota.

Knight,'^ in 1899, suggested that the so-called Permian beds of Nebraska,
Kansas, and Texas (including those of Oklahoma) were all connected origin-
ally and that they extended to the Rocky Mountains. In 1902 the same
writer "= referred the Red Beds of the Laramie Plains to the Paleozoic on both
stratigraphical and paleontologic evidence and showed that the invertebrate
fauna resembles that of the Kansas and Nebraska beds. He says:

' ' The Red Beds merge into the limestones or rest conformably upon them, and
here we have conditions very similar to those that have been recently discussed
from southern Kansas and southward. From our present knowledge it seems
advisable to refer the Red Beds of the Laramie Plains to the Permian."

He further states that others have mentioned that south of the Union
Pacific Railroad the beds rest on the Archean and north of it conformably
upon the limestone. He says:

"I have found that the Hmestones shade almost imperceptibly into the red
sandstones, and that the strata of the lower portion of the Red Beds are identical

" Beede, Kansas University Quarterly, vol. IX, p. 191, 1900.
>> Barbour, Geol. Survey Nebraska, vol. i, p. 129, 1903.

<= Darton, U. S. Geological Survey, Professional Paper No. 32, plates x and xi.
"i Knight, Jour. Geol., vol. vii, p. 369, 1899.
• Knight, Jour. Geol., vol. x, p. 420, 1902.
62

NORTH AMERICA AND THEIR VERTEBRATE FAUNA. 63

with the strata of the limestones to the northward, the difference in the lithological
characteristics being due to the varied physical conditions during sedimentation."

In 1907, Darton reported finding a fossiliferous limestone 150 feet below
the top of the Red Beds on the west slope of the Bighorn Mountains, 3 miles
north of Thermopolis, Wyoming." The Red Beds are here nearly i ,000 feet
thick and lie upon upper Carboniferous limestones and sandstones. This
limestone carries a Permo-Carboniferous fauna similar to that which has been
found in the basal portions of the Red Beds in adjacent regions. The occur-
rence of the fauna in the limestone mentioned leaves only 150 feet to repre-
sent the Triassic. In the vicinity of Laramie, Knight found fossils of upper
Carboniferous age. It was found that on both sides of the Laramie Moun-
tains the upper Carboniferous limestones and sandstones shade into red beds
toward the south. These are the same beds which were called lower Wyo-
ming by Eldridge on the Rocky Mountain front and Fountain by Gilbert and
Cross. The Chugwater Red Beds which overlie the upper Carboniferous to
the north continue unchanged on the Rocky Mountain front and overlie the
lower Wyoming and the Fountain formations. Williston regarded the beds
here called Chugwater as Triassic, from the evidence of vertebrate fossils,""
but the invertebrate favina is apparently Permo-Carboniferous.

In 1909, Darton'' wrote:

"The Pennsylvanian division, which consists mainly of shales and sandstones
in northern Wyoming, contains thick bodies of limestone, but on both sides of the
Laramie Mountains, south of the latitude of Laramie, this mostly gives place to
sandstone, largely of a red color."

In the same paper he stated that "in the eastern Front Range in Wyo-
ming limestone predominates in the Casper formation to the north, but much
reddish sandstone is included; farther south and in Colorado the formation
changes to red sandstones, constituting the 'lower red beds' or Fountain
formation " (plate 19, figs, i and 2). And again: '^

"Fossils found at various horizons in limestones in the Chugwater Red Beds
do not afford conclusive evidence as to age. Those in the lower limestones in the
Bighorn Mountains and other uplifts are believed to be 'Permian' in the sense in
which the term is used in the Mississippi Valley. Many fossils occur in the lime-
stone 150 feet below the top of the formation, on the east bank of Bighorn River,
3 miles below Thermopolis. According to Dr. G. H. Girty, the principal species is
Natica Iclia, usually considered diagnostic of the Triassic, but probably it is older.
Bakcwellia and probably Pleurophoriis may also be present, and an Aviciilipectcn
occurs resembling ^1. curticardinalis, which is characteristic of the Permo-Carbon-
iferous of Utah. Dr. Girty is inclined to correlate the fauna with the Permo-
Carboniferous of the Wasatch Mountain section. The 150 feet of red shales and
sandstones which overlie this limestone may possibly represent part of the Tri-

' Darton, Bull. Geol. Soc. Araer., vol. 17, p. 724, 1907.

''Williston, Jour. Geol., vol. 12, 1904.

' Darton, Bull. Geol. Soc. Amer., vol. xi.x, p. 403, 1909.

"^ Darton, U. S. Geological Survey, Professional Paper No. 62.

64 THE PERMO-CARBONIFEROUS RED BEDS OF

assic. In the lower portion of the Chugwater formation, lo miles southwest of
Casper, a cast of Schizodus wheeleri was found. The form is usually regarded as
Pennsy 1 vanian . "

In the Black Hills the Minnekahta and Opeche are regarded as probably
Permian. The Minnekahta is a light pinkish or purplish limestone grading
downward into purple, pink, and red shales, which weather with a nodvtlar
surface and finally pass rapidly into the deep red, sandy shale of the Opeche
formation. The Opeche is assigned to the Permian because red beds occur in
the Permian of Kansas and Nebraska as intercalated layers between lime-
stones. The material is a soft red sandstone and a red shale (plates 14
and 15).

In Professional Paper 32, United States Geological Survey, Darton dis-
cusses the character of the Red Beds of the Front Range of the Rocky Moun-
tains. The vipper Carboniferous limestone is found in the northern part of
the Front Range near the Wyoming line, and in the Culebra Range it appears
to merge into the Fountain Red Beds, which he believes to be the exact
equivalent of the lower Wyoming of Eldridge and the Badito of Hills, and
to represent the Amsden formation and overlying Tensleep sandstone of the
Bighorn Mountains and the Minnelusa formation of the Black Hills (p. 80).
The lower Red Beds of the Rocky Mountain Front Range have yielded no
fossils and undoubtedly merge into limestones both on the north and the
south and can be correlated with formations in the Black Hills and the Big-
horn Mountains. Darton says fvirther:

"Throughout the Black Hills, the Bighorns and much of the region to the south
the upper Carboniferous and Red Bed series presents a general succession as follows,
beginning at the top: A thick mass of gypsiferous, red, sandy shales; a thin mass
of thin-bedded limestone; a thin mass of red, sandy shales; a thick, hard, light-
colored, fine-grained sandstone; and, at the base, limestones and sandstones giving
place to sandstones and conglomerates, the basal series lying unconformably upon
the Mississippian limestones, on Cambrian, or on old granites and schist" (p. 159).

"Near the Colorado-Wyoming State line the upper Carboniferous limestone
may be seen to merge into red sandstones, apparently by the expansion of included
reddish sandy layers observed northwest of Cheyenne and a corresponding thinning
of the limestones. A mass of red sandstones and conglomerates, which lies at the
base of the limestones for some distance, is seen also to thicken gradually to the
south" (p. 161).

"The name 'Fountain formation' has been used to comprise all of the red beds
in the region northeast of Canyon and southwest of Puelalo, and if, as I believe, the
Chugwater (upper Wyoming) formation thins out a short distance south of the
Garden of the Gods, the Fountain formation corresponds in the main to the lower
Wyoming, and is the product of similar conditions at the same geological epoch.
I do not see the slightest reason for supposing that the two formations are not
equivalent.

"The character of the beds northwest of Pueblo and in the Garden of the Gods
region is precisely the same as in the district west and north of Denver, arid although
I made special search I could find no evidence of overlaps or unconformities of any
kind within the great uniform mass of red grit deposits.

Chart of Cohimn;tr Sections of the Blatk Hills, Bighorn, and Rocky Mountain Front Range. After N. H. Darton.

NORTH AMERICA AND THEIR VERTEBRATE FAUNA. 6$

"The upper and lower Wyoming are very distinct from each other from the
Garden of the Gods north to the State Hne, as recognized by the geologists of the
Hay den survey and clearly set forth in the Denver monograph, where the terms
'lower Wyoming' and 'upper Wyoming' were introduced. The upper Wyoming
consists mainly of fine-grained sediments extending from the 'creamy sandstone,'
which I believe to be the equivalent of the Tensleep, to the base of the Morrison
formation. It consists mainly of bright-red shales, always with a thin limestone
layer or series toward its base, and from Platte Canyon northward with a massive
pinkish sandstone at its top. The included limestone is believed to represent the
Minnekahta horizon of the Black Hills and other regions, indicating a short but
widespread interval of limestone deposition at this epoch in the West. The few fos-
sils found in this limestone unfortunately do not settle its age, but there appears to
be but little doubt that its representative in the Black Hills is Permian. The over-
lying red shales, with gypsum, in northern Colorado may be Permian or Triassic,
for the fossils in the limestones which occur near the top of the extension of this
series into the Bighorn uplift do not indicate whether the beds are Paleozoic or
Mesozoic.

"The Chugwater formation (upper Wyoming Red Beds) is only 140 feet thick
at the Garden of the Gods and appears to thin out and disappear a few miles south,
bringing the Fountain formation into contact with the Morrison, a relation due
either to nondeposition of the Chugwater beds or to their removal by erosion in pre-
Morrison times. As it is, the hiatus probabU- represents part of the later Carbon-
iferous, the Permian, the Triassic, and all of the Jurassic periods. South of the
Arkansas River some of the Chugwater beds probably appear again, although at
present their identity is not established.

"The Badito formation of Hills appears to be simply the Fountain formation of
Cross and Gilbert. The Sangre de Cristo formation to which Hills refers in the
Walsenburg folio appears to represent a great development of Fountain (or lower
Wyoming) deposits. It is stated that remains of an upper Carboniferous fauna and
flora occur in this formation, which is added evidence as to the age of the lower Red
Beds (Fountain-lower Wyoming) series. These beds overlie or merge into the basal
limestone series on the eastern slope of the Sangre de Cristo (Culebra) Range, in
which Mr. Willis T. Lee has discovered an extensive upper Carboniferous (Pennsyl-
vanian) fauna.

"The Red Beds revealed in the canyons of the southeastern Colorado can not
be classified with certainty from the present evidence. On Purgatory River and
Muddy Creek the principal body of red beds is separated from the Morrison forma-
tion bj' gypsum or gypsiferous shales, strongly suggestive of the Chugwater (upper
Wyoming) formation. It was immediately under this gypsum in Purgatory Canyon
that I found the shoulder bone of a supposed belodont. Mr. Willis T. Lee has traced
the Red Beds farther south into northeast New Mexico, where the gj'psiferous hori-
zon gives place to a massive sandstone, termed the Exeter sandstone, constituting
the summit of the Red Beds, a member which may represent the distinctive top
sandstone of the Chugwater formation in northern Colorado and in southern Wyo-
ming. The sandstone is prominent in the Two Buttes uplift, constituting the sum-
mit of the Red Beds, and is underlain by red shales, which contain a thin bed of
limestone, noted by Mr. Gilbert, strikingly like the Minnekahta horizon. I have
not made observations on the Red Beds in Kansas and do not feci that a comparison
of the published statements with my observations in the region north and west
should aid in the correlation" (beginning p. 162).

66 THE PERMO-CARBONIFEROUS RED BEDS OF

Girty" regards the Fountain formation as Pennsylvanian. Henderson,''
regarded the lower part as Mississippian and the upper as Pennsylvanian,
and David White,' from the evidence of fossil plants, would place it in
Potts ville time.

In Professional Paper 53, United States Geological Survey, Darton speaks
of the Red Beds of Colorado. He says that in southern Colorado the Red
Beds lie on an irregular surface of granite, except in certain cmbaymcnts, as
the ones at Manitou and Canyon City, where lower Paleozoic rocks intervene.
The Red Beds have been found to be an extension of the Red Beds under-
lying the Carboniferous limestone in southeastern Wyoming and of the Per-
mian and overlying Red Beds of Kansas.'^ The Red Beds of this region he
considers as divisible into three parts: (i) the Fountain or lower Wyoming
(the lowest), consisting of coarse red grits which he found to represent the
upper Carboniferous Hmestone of Wyoming; (2) the Tenslecp sandstone,
traced as far south as the Manitou embayment; (3) the gypsiferous red shale
and sandstone of the Chugwater, which represents the Red Beds of the Black
Hills and Wyoming. The lower part of the Chugwater he considers as Per-
mian, the upper part as Triassic or Permian.

Lee " has described the Red Beds of southeastern Colorado and north-
eastern New Mexico. He found in southeastern Colorado a great thickness
of red beds lying beneath a shale formation which he regards as Morrison in
age. These beds extend as far south as the valley of the Canadian River in
New Mexico, showing in the walls of the various canyons. The Red Beds,
which he regards as of Permian or Permo-Carboniferous age, consist of many
feet of red sandstone and shale lying unconformably beneath the Morrison
shales. It is certain that in the Canadian Valley, from Tucumcari to the
Conchas Canyon, the Red Beds are of Triassic age (plate 11 and plate 12,
figs. I and 2) ; this is shown by the contained fossils, phytosaurs and Lhiio,
collected by the author. In the same beds Darton found the remains of a
phytosaur on the Purgatory River in southeastern Colorado. The red beds
as described by Lee terminate above the heavy beds of gypsum and gyp-
siferous clay, but near Folsom, New Mexico, he found a heavy red sandstone,
the Exeter, lying unconformably upon the Red Beds. It is very probable
that this sandstone extends farther south than is mentioned by Lee, as a
heavy red sandstone equivalent to the Exeter in position is seen as far south
as the north wall of the Canadian Valley near Montoya, New Mexico. Con-
sidering the evidence of the fossils discovered, it seems probable that the red
beds described by Lee are Triassic in age.

» Girty, U. S. Geological Survey, Professional Paper 71, pp. 369, 370.

t Henderson, Jour. Geol., vol., 16, pp. 491, 492, 190S.

° White, U. S. Geological Survey, Professional Paper 71, p. 370-

■^ The Red Beds of Kansas have since been shown to be continuous, in part at least, with the Permian
limestones and not to overUe them. — E. C. Case.

<^ Lee, Jour. Geol., vol. ix, p. 393, 1901; Ibid., vol. x,p. 36, 1902; Jour. Geography, vol. I, p. 35, 1902;
Ibid., vol. II, p. 62, 1903.

Black
Hills

Bighorn Casper Hartville Laramie Northern Westof GarOen of Arkansas

Mountains Range Uplift Range Colorado Denver The Gods Valley

EXPLANATION

Sundance
[MarineJur^Ssic)

Limestone. sandy-

Sandstone, white, grey, buffjand brown
Red. sandy shale =

^■,L)':,J>- ;>V^

Red sandstone and conglomerate

Granite and achist

Gypsum in large deposits

o c?o

?''= Fossils
C= Cambrian

Top of Mississippian
E= Exeter sandstone?

Englewood
Wh.tewood J
iOraoviaan) \

1000 Feet

Chart of Columnar Sections of Carboniferous and "Red Beds" in the western part of the Plains Province. From Darton.
This chart gives Darton 's correlation of the beds, the author's exceptions are noted in the text.

NORTH AMERICA AND THEIR VERTEBRATE FAUNA. 6^

The following is a section given by Lee ^ near Exeter Post Office, in the
Canyon of the Rio Cimarron, northeastern New Mexico (abbreviated) :

Fcft.

Dakota, hard quartz sandstone 78

Morrison (?) shale, sandstone and limestone 200-205

vShales.

Exeter, sandstone red and variable in color 75

Unconformity.

Red Beds, red sandstone interstratificd with red and purple shales.

Henderson'' in 1908 gave an accotmt of the Permo-Triassic (?) of the foot-
hills formations of northern Colorado. He distinguishes the upper part of
the Wyoming as partly Permian.

"Lykins Formation. — Conformably overlying the Lyons is a series of variegated,
mostly thin-bedded sandstones and shales, rather friable, chiefly deep red in color,
with thin limestone bands, the upper part usually gypsiferous. In the Boulder
district Fenneman names these beds the Lykins formation. It is the exact equiva-
lent of the upper Wyoming of Emmons in the Denver Basin and the Chugwater of
Darton in northern Colorado. In the Denver Basin monograph it is given a thick-
ness of 485 to 585 feet, Fenneman makes it 800 feet in Four-mile Canyon, north of
Boulder, and Darton gives it a thickness of 380 feet at Lyons and 520 feet at Owl
Canyon. Though it varies greatly in thickness and in stratigraphic details, its gen-
eral characters are constant throughout the region. As a whole the formation is
non-resistant, the greater part being concealed by the debris in the lateral north-
south valleys caused by its destruction.

' ' From Owl Canyon to the Little Thompson I have mapped as part of the Lykins
a more resistant sandstone, strongly cross-bedded, which forms a ridge in the valley
and which sometimes extends nearly to the top of the east slope of the Lyons escarp-
ment (plate 18, fig. i). It is difficult to distinguish from the Lyons sandstone, and
should perhaps be assigned to that formation, but is uniformly separated from the
latter everywhere north of the Little Thompson by strata lithologically resembling
the Lykins. In approaching Little Thompson Canyon these intervening beds rapidly
play out, bringing the sandstone which is mapped as Lykins into contact with the
Lyons and making the former the crest of the escarpment, almost covering the latter.
Thence southward it is doubtful if the two sandstones can be recognized as distinct
formations, and nowhere have I found a noticeable unconformity. As the two sand-
stones after coalescing form an almost vertical escarpment, if they are distinct it is
practically impossible to represent the Lyons on the map, yet northward they are
quite distinct. The one which is mapped as Lykins in the northern region passes
beneath the 'crinkled 'sandstone of Fenneman's report, which is but a few feet above
the Lyons north of Boulder. This problem is worthy of future investigation.

"In some places certain strata of the Lykins are very massive, though soft, and por-
tions of the formation are locally calcareous, in addition to distinct limestone bands.

"In the absence of paleontological evidence this formation has been usually
assigned to Triassic- Jurassic age. It seems quite likely, however, that the base of
the Lykins may represent Permian time, as the immediately underlying Lyons is
upper Carboniferous. The upper part of the Lykins is probably Triassic or Jurassic,
as it is overlaid by known Jurassic in northern Colorado, though it is possible that
part of the Jurassic and Triassic is represented by the general unconformity between
the Lykins and the Morrison."

" Lee, Jour. Geol., vol. lo, p. 46, 1902.

'' Henderson, First Ann. Report Geological Survey of Colorado, 1908, p. 168.

68 THE PERMO-CARBONIFEROUS RED BEDS OF

Butters "in 191 3 gave a very detailed account of the " Permo-Carbonifer-
ous" of the eastern foot-hills of the Rocky Mountains in Colorado. After
detailing the conditions in the various sections from the north line of Colo-
rado south he says:

"Overlying this [the Ingleside] is the Lykins formation, and at one horizon about
200 feet from the base, at Heygood and Box Elder Canyons, Bellerophon crassus and
Myalina subquadraia were found. The same species are found in the Fountain and
Ingleside below. On this evidence, together with the fact that there is no angvxlar
unconformity, and no marked difference of lithological character, this basal portion
of the Lykins is assigned to the Pennsylvanian period. On the northern slope of Table
Mountain, Larimer County, 40 to 50 feet higher than the fossiliferous stratum, and
separated from it by a gypsiferous series, another fossiliferous stratum occurs. This
is probably more than 300 feet from the top of the Lykins formation and seems to
be in the same stratigraphic position as the fossiliferous beds near Stout, and also
those in the crinkled sandstone near Perry Park. At Stout, and also at Table Moun-
tain, the 'crinkly' structure is not present. From this horizon Dr. G. H. Girty has
identified the following fossils :

From Table Mountain: From Stout: From Perry Park:

Myalina wyomingensis. Myalina wyomingensis. Myalina wyomingensis.

Myalina peraltenuata. Myalina perattenuata, Myalina pcratlenuata.

Alula sqiiamulifera. Alula squamulifera.

MuTchisonia buttersi. Alula gilberti (?).

Pleurophorns sp.

"This fauna has recently been discussed, Alula squamulifera and Murchisonia
buttersi described as new, and Allerisma {Pleurophorellal) gilberti removed to the
new genus Alula, by Dr. Girty. ^

"It will be seen that the faunas are essentially the same, and, while some of the
species are new, the number of known forms is such that Dr. G. H. Girty believes
a tentative correlation with the Rico formation of the San Juan region is justifiable.
The Hermosa is Pennsylvanian, while the Rico is considered, tentatively, Permian.
This leaves 100 to 400 feet of shales to represent the Permian or the remainder of
the Permian, the Triassic, and all the Jurassic up to the Morrison. These sediments
are usually a soft red shale or shaly sandstone, and the conditions of deposition were
apparently unfavorable to the preservation of fossil evidence."

Later in the same article he says :

"Correlations. — The correlation of the Fountain, Ingleside, Lyons, and Lykins
along the foothills from the line to Colorado Springs is a question of recognizing the
same formation under different names. * * * Thus the Fountain of Fenneman in
the Boulder quadrangle is equivalent to the lower part of the Fountain of Cross in
the Pike's Peak area. The Fountain, Ingleside, and Lyons together are equivalent
to the lower Wyoming of the Denver Basin area. The Lykins is equivalent to the
Chugwater of Darton and the upper Wyoming of Emmons. The upper portion of
the Fountain and the Ingleside together are equivalent to Darton's Casper forma-
tion. The Lyons is equivalent to the creamy sandstone of the Denver Basin area,
but Darton's Tensleep is not the equivalent of the Lyons and the Creamy sand-
stone. It is a lower horizon, and can be correlated only with the lower portion of
the Lyons, and also the Ingleside. An explanation of this requires a description of

'Butters, Bull. 5, Colorado Geol. Survey, 1913, p. 65.
''Girty, Anns. N. Y. Acad. Sci., vol. 22, pp. 1-8, 1912.

NORTH AMERICA AND THEIR VERTEBRATE FAUNA. 69

the conditions in northern Colorado. This has been made under 'Formation
names.' Barton's Tensleep in Colorado is probably in part equivalent to the sand-
stone-limestone series; that is, the Ingleside series.

"Owing to the absence of fossil evidence in the Badito formation, and from the
fact that it is separated so widely from any recognized Fountain exposures, it has
not been definitely correlated with the Fountain. Lithologically they are very simi-
lar, and the Badito overlies pre-Cambrian rocks unconformably, bearing about the
same relation to the overlying formations as does the Fountain. On these grounds
they are at least approximately in the same horizon.

"The Cutler formation is defined as that portion of the 'Red Beds' lying above
the Rico, where that is present, or otherwise as succeeding the Hermosa and below
the Dolores. The Cutler is assigned to the Permian purely on stratigraphic grounds,
and is separated from the Rico by a purely arbitrary line. There seems to be as
good ground for assigning the Lykins, above the crinkled sandstone, or at least the
lower portion of it, to the Permian, and thus correlating it with the Cutler.

"Above the Cutler formation in the San Juan region is a series of sandstones,
sandy shales and conglomerates which vary in thickness from 800 to 400 feet, and
from that down to 30 feet at the San Miguel River, disappearing entirely north of
this river. These shales and sandstones are a bright vermilion in color, and are
known as the Dolores formation. They are assigned to the Triassic age because of
the scanty, but widespread, vertebrate, invertebrate, and plant remains. The ex-
treme upper part of the Lykins in Larimer County may be equivalent to the Dolores
and thus be Triassic. If so, it is impossible to draw a line between the Permian and
Triassic in eastern Colorado."

The following fossils were obtained by Mr. Butters from the Lykins
formation :

Lower horizon: Myalina subquadrata, Bdlerophon crassus.

Upper horizon (identified by Dr. Girty) : Myalina wyomingcnsis, Myalina

perattcnuata. Alula squamiilijcra, Alula gilbcrti (?), Pleurophorus sp.,

Murchisonia.

"Of the Lykins fossils all except Alula sqnamulijcra and Murchisonia buttersi,
which are new species, and Alula gilbcrti (?) are found in the Rico formation of the
San Juan region. Girty reports about 3 7 species from the Rico. Of these Bdlerophon
crassus and Myalina subquadrata and others also occur in the Hermosa. It will be
noticed by the list of the Lykins fossils that these two occur at a different and a
lower horizon in the Lykins than the remainder. This rather strengthens the corre-
lation of the Lykins with the Rico. Bdlerophon crassus and Myalina subquadrata
are found in the Hermosa and other Pennsylvanian horizons lower than the Rico.
Pleurophorus subcostatus and Pleurophorus occidentalis occur in several locahties,
but it is by no means certain that the Pleurophorus of the Lykins belongs to either
one of these species. A doubtful identification of Myalina wyomingcnsis has been
made from Leadville. With these possible exceptions none of the Lykins fossils
have been reported by Girty from any formations in Colorado other than the Rico.
In summarizing it will be seen that there is fairly good evidence for correlating the
Lykins with the Rico, and no evidence for correlating it with any other horizon. The
Lykins fossils were collected from localities a long distance apart — from the extreme
northern part of Larimer County in the north to Perry Park in El Paso County in
central Colorado — so that the Lykins appears to be more widely distributed than
the Rico."

70 THE PERMO-CARBONIFEROUS RED BEDS OF

While Mr. Butters correlates the Lykins with the Rico, he notes that the

fossils occur in regions which were separated by a land area at the time of their

deposition.

CONCLUSIONS.

From the facts brought together above, several interesting conclusions
may be drawn. It is shown that in the Bighorn and Laramie Mountains
the Carboniferous limestone shades into thin red beds, just as in Kansas,
Oklahoma, and Texas, and that the same thing is probably true of the Black
Hills and at least as far south as the north line of Colorado. Probably similar
relations could be found from southern Kansas to the Bighorn Mountains
were not the beds covered by later deposits. On the west, the upper part of
the Red Beds, Chugwater in part and Spearfish, are generally regarded as
Triassic, farther toward the south there is a distinction into upper Wyoming
and lower Wyoming (Fountain) formations. Darton, as quoted, believes
the upper beds to disappear a short distance south of the Garden of the Gods
and the lower Wyoming (Fountain) to appear in contact with the Cretaceous
or Jurassic, and with this the author is in accord. With many of the observa-
tions of Darton, the author, from recent study, is in full agreement, but he
does not feel that the various beds, as the Minnekahta, Opechee, etc.,
can be recognized so confidently in many places as Darton appears to do.
This is undoubtedly due in part to the author's lesser acquaintance with
the beds in question, but he still feels that prolonged study would not
render all of Darton's correlations entirely satisfactory to him, especially as
there is so much of terrestrial deposition, with its concomitant irregularity
of the beds.

The upper Red Beds of Colorado (upper Wyoming, Lykins) are grouped
by Darton with the Chugwater and Spearfish, and he refers to them as partly
Permian and partly Triassic. The lower portion of the Colorado beds is
certainly Permo-Carboniferous. Butters, as shown above, has collected fos-
sils from these beds which Girty calls "American Permian" {fide Gecjvge) ,
and this means practically the horizon of the Texas-Oklahoma beds. The
author studied the beds from Red Mountain, near Laramie, to where they
disappear south of Colorado Springs, with the greatest care, and, while no
trace of vertebrate fossils was found , the lithological similarity to the beds of
Texas and Oklahoma was so striking that, coupled with Butters's discovery
of fossils, the suggestion that these beds were laid down in a continuation of
the area of deposition in the south and under identical conditions is so strong
as to be almost conclusive. Color, texture, markings, included concretions, and
similar structures from one locality can be exactly matched in the other. The
author is convinced that the Lykins formation, at least as high as the base
of the pinkish, massive sandstone near its top (plate 17, fig. i), can be corre-
lated directly with the beds of Texas, so far as the conditions of deposition
and the continuity of the area of deposition goes. Whether the time of
deposition was exactly the same in the two areas is not certain, but the

NORTH AMERICA AND THEIR VERTEBRATE FAUNA. 7 1

time interval, whatever it may have been, was probably that involved in
a progressive or regressive movement of the conditions which determined
the deposits.

South of Pueblo there is a long, narrow strip along the east front of the
Sangre de Cristo range which is marked on the geological map of North
America as Permian, continuous with the Permian of the Pecos Valley. As
already shown (p. 60), the Triassic extends from the western edge of the
Staked Plains well over eastern New Mexico. The Red Beds described by
Lee and in part by the author are Triassic, from fossil evidence, and cer-
tainly a good part of the beds at Las Vegas Hot Springs are Triassic, as shown
by the dinosaur tooth found by the author near the middle of the series just
north of the Hot Springs (p. 61). The relation of the beds at Hot Springs to
those just south of the Garden of the Gods can be demonstrated only by a
careful foot-by-foot traverse and a very tedious search for fossil evidence.

The author believes that there was a Permo-Carboniferous area of deposi-
tion reaching from north-central Texas to the Black Hills and west to the
Front Range of the Rocky Mountains. South of the Garden of the Gods the
western edge of this area seems to have bent to the east in the latitude of
Las Vegas, or the deposits to have become very thin. How far this embay-
ment to the east extended is very uncertain; in the valley of the Canadian
River the Permo-Carboniferous Red Beds, Quartermaster and Greer, reach
at least to the center of the Staked Plains, but do not appear on the western
side. South of this they may have extended west to the Guadaloupe Moun-
tains, as suggested by Beede.''

The material of the Red Beds in the north and west originated in the
decay and erosion of igneous and early Paleozoic masses where now lie the
Black Hills and Bighorn Mountains and a greater mass extending west
from the present Front Ranges of the Rocky Mountains. The southern Red
Beds were largely derived from the igneous and early Paleozoic masses in
the position of the present Wichita Mountains and Arbuckle Hills.

Of this great area of similar deposits only a portion of the southern part
is well exposed, and of that only a small portion carries vertebrate fossils.
But we can at least attempt the delimitation of the whole area and show
what lands may have been the source of the sediments and the home of the
upland animals. (See plate 4, opp. p. 88.)

■ Beede, Amer. Jour. Sci., vol. xxx, p. 131, 1910.

CHAPTER III.

DESCRIPTION OF THE BASIN PROVINCE.

The region yielding Permo-Carboniferous fossils, in Rio Arriba County,
New Mexico, has already been twice described by the author and Dr. WiUis-
ton.' As shown by the faunal hsts (p. 96), the animals of the Plains and
Basin Provinces were quite distinct, not a single species and but a few doubt-
ful genera being common to the two. Whether the deposits in the two prov-
inces are of the same age or the western younger than the eastern is as yet
undecided. Dr. Williston beUeves that the fauna from the New Mexican
beds is more primitive, and so younger than that from Texas and Oklahoma.
Dr. Schuchert is inclined to believe the New Mexican deposits younger from
the evidence of the invertebrates. The Hucconian fauna of Girty ^ is "quite
different from those of the Pennsylvanian of the Mississippi Valley and are
mostly undescribed." The Guadalupian life "is quite unlike the faunas of
eastern North America, and almost equally unlike those of the West." Girty
also remarks that the Hueconian fauna is likely to be found widely extended
in the West.

In Wyoming there are two distinct faunas which are closely approxi-
mated, geographically. Knight found invertebrate fossils near Red Moun-
tain, Wyoming (plate 16, fig. i), distinctly similar to those of the Kansas
Permian (?) limestones, but farther west a different fauna occurs. In
detail :

Near Red Mountain Knight' found, 728 feet above the base of his section,
a fossiliferous layer of "grayish to reddish sandstone containing the following
genera of fossils: AUorisina, Pleiiroplwrns, Bellerophon, Myalina, Aviculo-
pecien, DentalUum (?), Pleurotomaria (?), several small gastropods, and some
remains of vertebrates. * * * The genera (in the fossiliferous layer in this
section) are so characteristic that it is unnecessary to discuss their geological
position; they belong to the Paleozoic and resemble to a marked degree the
fossils of the Kansas and Nebraska Permian." (Plate 16, figs, i and 2, and
plate 17, fig. 2.)

In the Park City mining district Bartwell"* distinguished three forma-
tions, the Woodside, Thaynes, and Ankareh:'

"The Woodside is a fine-grained unfossiliferous red shale 700 to 1,180 feet
thick, which overlies unconformably the Park City formation (Pennsylvania). The
Thaynes is characteristically calcareous and rich in fossils. It is i , 1 90 feet thick. In

"Williston and Case, Jour. Geol., vol. xx, p. i, 1912; Carnegie Inst. Wash. Pub. 181, p. i, 1913.

>' Girty, U. S. Geological Survey, Professional Paper No. 58.

' Knight, Jour. Geol., vol. 10, p. 419.

"• Bartwell, Jour. Geol., vol. 15, 1907, p. 439'

° Quoted from U. S. Geological Survey, Professional Paper No. 71, p. 494-

NORTH AMERICA AND THEIR VERTEBRATE FAUNA. 73

1907 Girty reported that the fauna and horizon are those which in the Fortieth
Parallel Survey reports are called Permo-Carboniferous, and said : ' It seems prob-
able that the fauna will be correlated with the Permian of the Grand Canyon
section.' "

Girty later referred these fossils to the Triassic and "almost certainly
equivalent to the Triassic of Idaho." His latest statement, in 1910,^ seems
to indicate his belief that there are deposits of Permian or Permo-Carbonif-
erous age in this region. He says:

"In notable contrast to the Weber formation, the beds above the Park City
formation show striking persistence in their main lithological and paleontological
characters. These are the ' Permo-Carboniferous ' beds of the King survey and were
divided by Boutwell in the Park City district into the Woodside, Thaynes, and
Ankareh formations. It seems all but certain that the 'Permian' of Walcott's sec-
tion in the Kanab Canyon, in southern Utah; the 'Permo-Carboniferous' of the
Wasatch Mountains in northern Utah; and, in part, the 'lower Triassic' of south-
eastern Idaho are one and the same series. The Woodside, Thaynes, and Ankareh
do not, perhaps, maintain precise boundaries throughout all this territory, and in
Idaho the first occurrence of Triassic ammonites (Meekoceras beds) is convention-
ally taken as the base of the Thaynes.

"The Triassic age of at least the major portion of the 'Permo-Carboniferous'
(Thaynes and Ankareh) seems to be shown by fairly satisfactory evidence — the
presence of an extensive ammonite fauna of Triassic type and the practical absence
of any distinctive Carboniferous forms. In advance of a detailed study of these
faunas, however, it may be pointed out that above the Meekoceras beds there are
zones which contain great numbers of Rhynchonella closely related to the Carbonif-
erous Pugnax Utah and many specimens of apparently true Myalina, not unlike
Carboniferous species.

" It is much less certain that the Woodside formation is not Paleozoic (Permian ?) .
A preliminary study of the Woodside shows that, except that it has yielded no am-
monitic forms, it does not differ materially from the fauna of the Thaynes and
presents a strong contrast to the Carboniferous fauna of the Park City. Lithologi-
cally also there is a well-marked division between the Woodside and the Park City
formation, and no lithological boundary can be traced between the Woodside and
the Thaynes. That the Woodside, Thaynes, and Ankareh form a natural group is
indicated by the classification of the rocks adopted by most geologists. If the
Thaynes is Mesozoic, the obvious line between the Mesozoic and the Paleozoic would
seem to be the line between the Park City and the Woodside. If, then, as may be
tentatively concluded, the Woodside does not represent the Permian, the natural
question to follow is: Does the Park City formation belong in the Permian? A
decisive judgment on this point should wait upon a careful study of the faunas
obtained from other members of the Park City beds, as well as upon a study of other
related faunas less certainly appearing at the same horizon. Because of the close
relationship or identity of many species of these faunas with the Gschelian faunas
of Russia, I am provisionally holding that the Park City formation is older than the
Permian.

"Any one at all familiar with the Carboniferous faunas of the Mississippi Valley
will at once recognize that the forms found in the phosphate beds, individually as
well as collectively, are quite different from the forms found in that area."

'Girty, Bull. U. S. Geological Sun'ey No. 436, pp. 7-10, 1910.

74 THE PERMO-CARBONIFEROUS RED BEDS OF

In further remarks in the same paper Girty suggests the possibiUty that
the beds under discusion, together with many other beds in the western part
of the United States, may be found to be GscheHan in age.

Girty" regards the invertebrate collected by Darton in Gilmore Canyon
(270 feet above the 24 feet of limestone in the Casper) "as very closely
related to that of the upper part of the Pennsylvanian division in the Kansas
section."

The Forelle limestone and Satanka sandstone above the Casper south
of Laramie are in part gypsiferous. It was in the former that Knight's
fossils were found.'' According to Girty, the fauna is "late Pennsylvanian
or possibly equivalent to the Wreford limestone in the so-called Permian of
Kansas. ' ' These two beds are separated from the Chugwater by the Carbonif-
erous character of the fauna, "otherwise it might be regarded as a portion
of the Chugwater formation from near Laramie and Red Buttes. The
stratigraphic succession is strongly suggestive of Minnekahta limestone lying
on Opechee red shale. The latter limestone occurs on the east side of the
Laramie Mountains and in the Black Hills, and contains ' Permian ' fossils in
the sense in which the Permian is used in the Mississippi Valley. The Forelle
limestone may possibly represent the Embar formation."

A little farther west and south on the west side of the Bighorn Mountains
the Embar limestone occurs in the Owl Creek and Wind River Mountains
and eastward.

From the walls of the Bighorn Canyon Girty determined Spiriferina
pidchra, which "is believed to characterize a horizon just below the so-called
Penno-Carboniferous of the Wasatch Mountains region," and, as Dr. Girty
correlates the latter with Permian of the Grand Canyon section, the occur-
rence of these fossils in the Embar limestone suggests that this formation is
equivalent to the upper Aubrey limestone of northern Arizona. According
to Girty:

"The Embar limestone has a very different fauna from the Kansas Permian,
but it may be equivalent to it or even later. The fauna is not related to the Guada-
lupian. It occurs in Utah just below the Permo-Carboniferous and is known also
in Idaho and Nevada."

West and north of the Permian deposits in Rio Arriba County, New
Mexico, is a large series of red beds which undoubtedly contain Permian or
Permo-Carboniferous series deposited in the Basin Province. Cross and Howe"
have described the formations around Ouray, Colorado, separating the
Cutler formation as Permian from the Dolores (Triassic) above and the
Rico and Hermosa (Pennsylvanian) below. An vmconformity separates the
Dolores from the Cutler, but there is no stratigraphic break between the
Permian and Pennsylvanian. The description given by Cross and Howe"^

" Girty, in Darton, Bull. Geol. Soc. Amer., vol. 19, p. 429.

'' Darton, Bull. Geol. Soc. Amer., vol. 19, p. 431; Knight, Jour. Geol., vol. x, p. 419.
" Cross and Howe, Bull. Geol. Soc. Amer., vol. 16, p. 461, 1905.

■^ Cross and Howe, Bull. Geol. Soc. Amer., vol. 16, p. 461, 1905; see also U. S. Geological Survey,
Professional Paper No. 7X, p. 480.

NORTH AMERICA AND THEIR VERTEBRATE FAUNA. 75

of the Cutler and adjacent formations shows them to have the same character
as other Permo-Carboniferous beds, but to include larger pebbles and coarser
fragments, indicating the proximity of at least a local source of supply in the
Basin Province.

Similar deposits are found to the north in west central Colorado.''

Farther west the Permo-Carboniferous of the Uintah and Wasatch
Mountains carries marine invertebrate Spirifcrina pulchra, Myalina, Avicii-
lopecten, etc., so it is possible that the Red Beds bordered an open sea, which
extended to the west. The Permo-Carboniferous of these mountains are,
according to Girty, equivalent to Walcott's Permian in the Grand Canyon. *"

Permian beds have also been determined in the Zuni Plateau of New
Mexico by Button,'' which correspond in lithological character and fossils with
those determined by Walcott in the Kanab Canyon and are terminated above
by the coarse basal, Triassic, Shinarump conglomerate.

Darton'' regards the Moencopie of Ward in northeastern Arizona as Per-
mian. Walcott" located Permian deposits in Kanab Canyon of northeastern
Arizona.^ The occurrences here mentioned show the typical character of red
beds, and the few fossil invertebrates collected point to their Permian or
Permo-Carboniferous age. The beds are not described in detail, for as yet
no vertebrate fossils have been found in them, and the object of the present
chapter is only to show the probable outlines of the Basin Province.*-'

The original papers are easily accessible and the essential parts of the
discussion are repeated in Professional Paper No. 71, United States Geologi-
cal Survey, pages 479-486.

Professor Gregory, in conversation with the author, stated that the Shina-
rump conglomerate does not occur east of the western edge of New Mexico
(Mount Taylor and Fort Wingate regions). As this is a strong and very

" Cross, Gcolog. Atlas of the United States La Plata folio (60); Silverton folio (120).

■■ Girty, U. S. Geological Survey, Professional Paper No. 71, p. 485.

" Dutton, Sixth Ann. Rpt. U. S. Geological Survey, 1885.

•^ Darton, Bull. U. S. Geological Survey, No. 435, pp. 32-36, 1910.

" Walcott, Amer. Jour. Sci., 3d series, vol. 20, pp. 221-235, 1880.

' Dr. Girty informs the author that a portion, at least, of Walcott's Permian has been shown to be
Triassic by the discovery of typical cephalopods.

s In the summer of 1913 the author, accompanied by Mr. Emery of Yale University, discovered impres-
sions of a conifer in the lower part of the Moencopie, a few miles west of Fort Defiance, Arizona. These
specimens were submitted to Mr. David White, wlio gives the following report upon them:

"The large fragment with closely placed lateral twigs belongs to another Walchia resembling the Wal-
chia hypnoides. It is perhaps identical with that described by Dawson as Wakkia gracilis. One or two small
fragments in one of the loose rock pieces agrees still more closely with Walchia gracilis. These forms of
Walchia are characteristic of the Permian, and are present in Oklahoma and in the Wichita formation of
Te.xas."

A few days later the author found the interclavicle of a large stegocephalian in a bed of conglomerate
20 feet below the base of the Shinarump conglomerate, but still well within the Shinarump formation, as it
is now regarded by Gregory (letter from Dr. Gregory to the author), at Tucker's Spring, about 10 miles
northwest of Winslow, Arizona. This interclavicle closely resembles that described by Lucas as Metoposaurus
fraasi from near Tanner's Crossing on the Little Colorado River. It is probably a form nearer to A naschisma ,
a typically Triassic form. Lucas described another fossil from near the locality where his Meloposaiirus
was found and called it Placerias, referring it to the Cotylosauria. Broom, in conversation with tlie author,
stated his belief that this fossil belonged to the South African group, Dinocephalia.

76 THE PERMO-CARBONIFEROUS RED BEDS OF

widespread formation in southern Colorado, Arizona, and western New
Mexico, its absence at all points east in the same latitudes is of considerable
significance.

The limits of the Basin Province are less certain than those of the Plains
Province, but it is certain that the area of Red Bed deposition of Permo-
Carboniferous time covered northern Arizona and New Mexico and extended
north through western Colorado into Wyoming. Its western side seems to
have terminated in a limestone-forming sea coveiing the site of the Uintah
and Wasatch Mountains, and its eastern side rested against the land-mass
which sepai-ated it from the Plains Province.

Opposed to the proposition of a separate (Basin) area of deposition is the
discovery by Weeks '^ of certain fossils on the southeast slope of Hamcl's Peak,
some miles south of Ely, Nevada, which Girty determined and regarded as
of a "similar fauna to that of the Marion formation of the Kansas section,
which Prosser regards as a Lower Permian fauna, and it can probably be
safely correlated with the Marion." The list is:

Productus sp. Bulinwrpha pcracnta.

Nuciilana cf. obesa. Murchisonia, near marcouiana.

Plcurophorus? sp. Bdlcrophon sp.

Schizodus sp. Dimatoceras sp.

Straparollus catilloides. Ostracoda.

Pleurotimaria humerosa. Bakewellia parva.

The lowest beds observed in Arizona and New Mexico, San Jose region,
occtir in the axis of an anticline 8 miles west of Rio Puerco Station, 20 feet of
greenish-gray shales with thin sandstone layers and an inch of coal at top.
Fossils from this locality are given by Darton'' as:

Myalina perattcnuata. Bakewellia (?) sp.

Myalina penniana. Btdlimorpha, near B. nitidida.

Aviculopecten cf. A. whitei. Spirorhis sp.

These are related to the Permian fauna of the Mississippi Valley.

Keyes'^ says that red beds of the Bernalillo shale nearly 1,000 feet thick
occur in the Sandia Mountains above the dark-blue and black limestone
and carry abundant fossils which "correspond faunally with those found in
the upper part of the Oklahoman scries of Kansas." He refers to the Report
of the Governor of the Territory of New Mexico to the Secretary of the
Interior, page 339, 1903. This report docs not mention fossils in the Bernalillo
shale, but does in the blue and black limestone beloiv, referring them to
Carboniferous of the Mississippi Valley.

The evidence here cited is not sufficient to raise a great objection to the
existence of separate basins of deposition. It is very possible that there may
have been short and local extensions of the seas of the Plains Province to
the west.

" Spurr, Bull. U. S. Geological Survey No. 208, p. 52, 1903.
^ Darton, U. S. Geological Survey, Bull. 435, p. 37, 1910.
" Keyes, Iowa Acad. Sci., vol. 15, p. 144, 1908.

CHAPTER IV.

DESCRIPTION OF THE PERMO-CARBONIFEROUS BEDS IN EASTERN

NORTH AMERICA.

IOWA.

East of the beds in Texas, Oklahoma, and Kansas, no vertebrate fossils
of Permo-Carboniferous age have been found closer than Illinois, but certain
deposits in Webster County, Iowa, have been doubtfully referred to the
Permian, and more or less directly coiTelated with the western deposits.
Wilder'' describes the deposits around Fort Dodge as red shales and sand-
stones, with considerable gypsum lying unconformably upon the St. Louis
limestone.

The narrow sea in which was deposited the Wreford and overlying lime-
stone in Kansas and southern Nebraska probably did not extend much
farther east than Ozarkia, though its easternmost deposits have been removed
by erosion. To the north it may have extended into southwestern Iowa (see
Schuchert's Paleogeographic map of the Late Permian), and even into north-
western Missoiui.

The author has recently examined the beds in the vicinity of Fort Dodge,
Iowa, and found nothing either in the character of the material or the mode
of deposition which would warrant the assumption that they were in any
way connected with the Red Beds deposits farther west. The red and parti-
colored clays and shales have in many places the appearance of residual clays
formed by the decomposition of a limestone. There can be little doubt that
they were formed in the last part of the Paleozoic and so may, perhaps, be
reckoned as Permo-Carboniferous, possibly formed at the same time as the
Red Beds, but under radically different conditions, either as the result of
mature decomposition of the land surface east of the Permo-Carboniferous
sea or in some inland body of swampy water.

East of Iowa no deposits referable to the Permo-Carboniferous are found
nearer than eastern Illinois. This is easily understood when we reflect how
long the region had been exposed to erosion, and how slight and thin must
have been the deposits, which were essentially terrestrial or fluviatile, or
perhaps occasionally lacustrine.

ILLINOIS.

The nature and exact age of the limited deposits near Danville, Vermil-
ion County, lUinois, is still doubtful. The suggestion by Baur and Case,
following Cope, that they are accumulations from a Permian river which
excavated its channel in the Pennsylvanian limestone has been questioned by

•Wilder, 12th Annual Report, Geological Survey o£ Iowa, p. 631. Norton and others. Underground
Water Resources of Iowa, U. S. Geological Survey, Water Supply Paper No. 293, p. 86.

6 77

^8 THE PERMO-CARBONIFEROUS RED BEDS OF

Williston and Weller, though the existence of just such deposits, the Merom
sandstone, in closely adjacent regions in Indiana lends considerable support
to the suggestion. The later recognition that the age of the vertebrate fos-
sils is much greater than was originally supposed, and that they must be
considered as Permo-Curboniferous rather than Permian, removes the need
for such an hypothesis, in large measure. Concerning these beds, I quote
from a letter from Dr. Williston, of April i8, 1912:

"We found fossils on practically the same horizon, about 300 feet distant, lying
above a limestone layer, whose horizon was definitely fixed as Pennsylvanian. The
fossils occur in a clay bed almost precisely like that of the Baldwin quarry [a black,
soapy clay — Case], near the water's edge and about 100 feet below the top of the
bank of the river. In my inspection I felt pretty confident that the fossils lie in
their original undisturbed position. Weller is inclined to believe that the clay beds
have slipped down from a higher altitude. If they are in their original position they
certainly are 200 or 300 feet, at least, below horizons which are clearly Pennsylvanian.
There is not the slightest evidence of an unconformity or any old 'Permian' river
channel. If Weller is correct, the fossils may have come from near the top of the
Pennsylvanian, but still distinctly Pennsylvanian. If my opinion is correct, they
are a considerable distance below the top of the Pennsylvanian."

INDIANA.
It would be idle in the present state of our knowledge to speculate upon
the condition of the eastern part of the Mississippi Valley in late Pennsyl-
vanian and Permian times, but we can at least be certain that it was exposed
to erosion, and deeply trenched in places by large streams. Definite remains
of such are found in Indiana. Some of these old stream-channels preserved
as the Merom sandstone have been described by Blatchley and Ashley" in
the Annual Reports of the Indiana Geological Survey.

"The Merom Sandstone: Division /.Y.— Just as the main body of the Coal Meas-
ure is underiain with unconformability by a massive sandstone, so it is also overiain
with unconformability by a massive sandstone. In the earlier reports this sandstone
was designated the 'Merom Sandstone,' from its excellent exposure at that point.
It there, as in the covmties to the south, lies on an eroded surface of the Coal Meas-
ures, its' lowest member consisting of a calcareous conglomerate containing shale,
coal! pebbles of sandstone, etc. To the north, in Parke and Fountain Counties, and
Vermilion County, Illinois, occur a number of extensive channels cut down into the
Coal Measures to a depth ranging up to 200 feet, and filled with a sandstone very
similar in many respects to the sandstone at Merom, Sullivan County. Though
no such readily distinguishable channels were found in the southern part of the coal
field, the position of the sandstone there, relative to the coal below it, indicates
extensive erosion. If we are correct in correlating the massive sandstone of the
channel fillings in the north part of the coal area with the overlying massive sand-
stone of the southern part of the area, it would appear that this sandstone was laid
down at no inconsiderable time after the laying down of the Coal Measures proper.
The great depth and width of the stream-channels cut out of the Coal Measures
prior to its deposition suggest a long time interval. So far as known, no fossils have

» Blatchley and Ashley, Geological Survey Indiana, vol. 23, pp. 80, 81.

NORTH AMERICA AND THEIR VERTEBRATE FAUNA. 79

been found associated with this sandstone in Indiana. In lUinois, however, some
fossils were some time ago found in some shale thought to be of the same age as the
Merom sandstone. The possible Triassic age of the fossils led Mr. Collett to suggest
that the Merom sandstone might be of the Triassic age. Concerning these fossils he
says: 'Adjoining this locality (section 2 5, Township 19, Range 13, Vermilion County,
Illinois) Dr. J. C. Winslow, of Danville, Illinois, discovered a bed of fossils which is
named in his honor "Winslow Bluff." They occur in a bed of black, brown, gray,
red, and pink shales, backed with sandstone, filling a depression denuded by forces
acting at the close of the coal age, which has carried away the regular deposits, in-
cluding probably three seams of coal.' "

"We can only say, at this time," the question is still an open one. If the correla-
tions of the channel sandstones of Parke County, which fill channels which cut down
to and through Coal III, correlate with similar sandstone of Illinois, and with western
Indiana, then it will be seen that previous to their laying down, the Coal Measures
of the State have been tilted at an angle that would place nearly their whole thick-
ness above sea-level in Parke County, while a score, or a little over, of miles away
to the southwest, nearly the whole of the Coal Measure column, as preserved in the
State, seems to have been under water. The exposed conditions of the eastern part
of the measures seem to have resulted in the strata from Division VI up having been
carried away, with valleys extending down into the measures to Division III."

"Coxville Sandstones {Merom?) :^ "Not only are channels cut down through the
measures, but there appears to have been extensive, though shallow, erosion for some
distance either side of the immediate channel, also filled with sandstone. The evidence
points to either a short time after the laying down of Coal VI, or to a time entirely
subsequent to the deposition of the Coal Measures proper; or at a time correspond-
ing with the laying down of the Merom sandstone of Sullivan County. The latter
theory is considered as best sustained."

"In the east of Raccoon Creek,"^ opposite Coxville, is the exposure of a sandstone-
filled erosion channel, which has been given the name of Coxville Carboniferous
River. As this sandstone was, by the old survey, considered to be a ridge of Mans-
field sandstone, the following sketch (fig. 12) is given, showing the true relations.

/Quarry and

I gloss-sand worKs

Wheats Mine
Coal VI at I

rock house

: *(!:>;

^eveT of bottoms ^ j-'"

Fig. 12. — Diagram showing rock exposure across Raccoon Creek from Co.wille, Indiana,
to show relation of Coal VI to sandstone at the crossing of the "Coxville
Carboniferous River." (After Blatchley and Ashley.)

"The charmel proper is some 600 feet broad and exposed to a depth of at least
40 feet, and how much deeper is not known. The sandstone of this filling is
massive, hardly showing a suggestion of bedding. Toward the west side is a little of
the appearance of cross-bedding, or perhajDS more closely resembling sand-dune struc-
ttu-e. Above this 40 feet of exposed channel the sandstone rises without perceptible
break or change another 1 5 feet, but now spreads out on either side. On the east
side this can be traced some 100 feet or so, by a clean exposure, to a rock-house,

• Blatchley and Ashley, 23d Annual Report State Geologist Indiana, p. 82.
'> Blatcliley and AsMey, 23d Annual Report State Geologist Indiana, p. 300.
'Blatchley and Ashley, 23d Annual Report State Geologist Indiana, pp. 385, 386.

8o THE PERMO-CARBONIFEROUS RED BEDS OF

where Coal VI is seen immediately underlying the sandstone. On the west the ex-
tension of this vtpper sandstone can be traced some distance, though poorly exposed
for the first 150 yards, and there, too, it immediately overlies CoaLVI. The age of
the sandstone is thus put as late as the age of the horizon of Coal VI. Farther
south there is commonly met with a nonconformability a little above Coal VI, and
accompanying measures are often cut out and replaced by sandstone. The erosion
is both of the channel and broad-wash order, the channels having been noted as
much as 16 feet deep. It, however, seldom does more than remove the top of the
coal, and not a single instance is recalled of its having cut through and below the
coal. There is, thus, some evidence suggesting that the sandstone at Coxville be-
longs to the period of Division VI, but there is also some evidence that it belongs to
a much later period. If, as has been suggested, this is a i^art of the same channel, or
system of channels, as at Silver Island, Rockport, Mecca, and other places to be men-
tioned, it has cut channels 150 feet or more deep, extending almost, if not quite,
through the measures. Such channels require some time for their cutting, and it
would seem as though, if this took place during the time period of Division VI, there
should be more general evidence of a marked conformity than there is. The assump-
tion of an unusually large uplift in the northeastern part of the coal field during that
period might in part explain its absence elsewhere. For the present the cjviestion
must remain an open one. The course of this channel was not discovered, but it
appeared to cross the creek near Coxville, and go west, or south of west, coming from
the north."

"Coal Measure on Sugar Creeks — -The coals in this district are comprised in
sections 23-26, 35, 36.

"The coal in this district is very irregular, due apparently to this being in the
path of the old Coxville Carboniferous River, met with at Silverwood. Not enough
detailed work was done to settle this question definitely, but from what was noted
we were led to surmise that the old river-channel crossed Sugar Creek at Rockport.
The resemblance of the sandstone filling to the Mansfield sandstone exposed both
up and down the creek, and the failure to find just the data needed, render this
opinion somewhat doubtful. There are, however, some outside data that tend to
confirm that theory; principally, that this old filled channel is plainly exposed at
Silverwood, and the appearance of certain sandstones in section 5 of this township
indicates that the channel was not very far away. Evidences of it are next met to
the south along the middle course of Roaring Creek, and in the region of Sand Creek.
Rockport is in the line between these places, and is, moreover, the only place along
Sugar Creek where such a crossing appears to have taken place."

OHIO.

In eastern Ohio and Kentucky and in western West Virginia and Penn-
sylvania the middle Conemaugh beds resemble in many characters the Red
Beds of Texas and Nevi^ Mexico, and in both Ohio and Pennsylvania remains
of reptiles and amphibians have been reported. In Pennsylvania the remains
have been shown to be very similar to those found in Texas and Illinois; in
Ohio very primitive forms, Eosaiiravus copei Williston, have been found at
Linton, with numerous Amphibia, and other as yet undescribed forms have
been found in other horizons.

" Blatchley and Ashley, 23d Annual Report State Geologist Indiana, p. 345.

NORTH AMERICA AND THEIR VERTEBRATE FAUNA. 8l

Condit* describes the general outline and condition of these deposits:

"The Conemaugh formation outcrops in a broad band, lo to 20 miles wide,
across the southeastern part of Ohio, and extends eastward, under cover, into West
Virginia and Pennsylvania, again rising to the surface towards the eastern edge of
the Appalachian coal basin. The strata included within this formation lie between
the base of the Pittsburgh and the top of the Upper Freeport coal, and have a thick-
ness in Ohio of 355 to nearly 500 feet. The area of outcrop * * * extends eastward
across Pennsylvania around the northern margin of the Appalachian coal basin,
thence southward through western Maryland and eastern West Virginia. From
southern Ohio the exposures may be traced into eastern Kentucky and West Virginia.
Hence, it is evident that, structurally, the ' Coal Measures ' area of Pennsylvania,
Maryland, West Virginia, Kentucky, and Ohio is a broad synclinal basin, into which
the rocks slope from the margin. The gentle southeasterly dip in Ohio is persistent
for a distance into West Virginia, carrying the Conemaugh strata hundreds of feet
below drainage, but beyond the middle of the basin the rocks rise again to the
surface.

"As to the lithological character, the formation consists mostly of sandstone,
sandy shale, and clay, much of which has a reddish-brown color. Coal seams and
limestones are few and thin. All the beds are characterized by lack of persistence,
and vary greatly as to thickness and appearance from place to place. Local erosion
planes and unconfonnities of small magnitude are extremely abundant and occur
at all horizons. The hiatuses are shown by conglomerates and truncated strata.
Frequently the material of the conglomerates can be traced to some nearby fossilif-
erous limestone bed or coal-seam.

' ' Much of the lower half of the Conemaugh formation is of marine origin and
has a number of fossiliferous horizons. The highest fossil-bearing beds, lying a
little above the middle, mark the final invasion of the sea into the Appalachian
Basin. All the overlying strata lack forms of undoubted marine origin, the fossils
being mostly plant remains, certain minute fossils, such as Spirorbis, ostracods, and
gastropods, generally regarded as fresh- water, together with occasional fish, amphib-
ian and reptilian bones. Insect remains are sometimes found well preserved in the
shales. The marine limestones of the lower half of the formation are the most per-
sistent and lithologically uniform beds, but these have suffered contemporaneous
erosion and locally failed to form, owing to the unfavorable conditions, such as the
presence of shoals in the sea and continuous sedimentation from rivers."

Condit '' gives the following list of the beds in the Conemaugh formation

in Ohio and their equivalents in West Virginia:

Ohio. West Virginia.

Pittsburgh limestone Upper Pittsburgh limestone.

Little Pittsburgh coal (upper).
Bellaire sandstone Lower Pittsburgh sandstone.

Little Pittsburgh coal (lower).

Summerfield limestone Lower Pittsburgh limestone.

Connellsville sandstone Connellsville sandstone.

Little Clarksburg coal Little Clarksburg coal.

Clarksburg limestone Clarksburg limestone.

Morgantown sandstone Morgan town sandstone.

Elklick coal.

Elklick limestone.

Birmingham shale Birmingham shale.

Skelly limestone.

Ames limestone Ames limestone.

' Condit, Conemaugh Formation in Ohio, Bull. 17, Geol. Bur. Ohio, p. 14, 1912.
'■Condit, Geol. Sur. Ohio Bull. 17, p. 20, 1913.

g2 THE PERMO-CARBONIFEROUS RED BEDS OF

qhio. West Virginia.

Harlem coal Harlem coal.

Roundknob horizon Pittsburgli red shale.

Barton coal Bakerstown (?) coal.

Ewing limestone.

Cowrun sandstone (?)

Portersville fossiliferous horizon:

Anderson coal Bakerstown (?) coal.

Cambridge limestone Cambridge limestone.

Wilgus coal.

Buffalo sandstone Buffalo sandstone.

Brush Creek fossiliferous horizon . . Brush Creek limestone.

Mason coal Brush Creek (Mason) coal.

Mahoning sandstone horizon:

Upper Upper Mahoning sandstone.

Mahoning coal Mahoning coal.

Lower Lower Mahoning sandstone.

Of these formations only the Birmingham shale, the Round Knob Forma-
tion, and the Ewing limestone have yielded remains of reptiles or amphibians.

The Birmingham shale was named by Stevenson from its position near
Birmingham, a suburb of Pittsburgh, Pennsylvania. It lies here 30 feet above
the Ames limestone and is from 35 to 50 feet thick. A thin coal-seam at the
base has been named by Raymond the Duquesne coal. Just above this coal
are found plants, Esthcria and fish teeth {Diplodus).

• ' This shale'' is also present in Ohio and, as at Allegheny, has a thin coal (Duquesne
of Raymond) marking the lower limit. The Elklick coal of Pennsylvania and West
Virginia sections is wanting in Ohio, hence the upper limit of the Birmingham is not
definite. Immediately over the Duquesne coal is a persistent fossiliferous limestone,
which is named the Skellv, from exposures at Skelly Station on the Pennsylvania
Railroad, in Jefferson County, about 10 miles west of Mingo Junction. This bed is
25 to 40 feet above the Ames hmestone and occurs nearly everywhere in eastern
Ohio, excepting where replaced by massive sandstone * * * .

'"' In addition to the marine fauna, the shales have also insect and reptilian re-
mains. The cockroach fauna from near Richmond, Ohio, collected by Samuel
Huston, of Steubenville, and described by S. H. Scudder in Bulletin 124 of the
United States Geological Survey, is accounted for as coming from shales a little
above the 'crinoidal limestone.' It is probable that this material is from the
Birmingham horizon. Professor Scudder Usts 22 species from this locality, belong-
ing to the genera Etoblatthm, GcrablaUina, and Poroblattina, 17 of which are of the
genus Etoblattina. A long Hst is also given from Cassville, West Virginia, collected
from the base of the Dunkard formation, and Professor Scudder ' remarks that,
although this locality has no species in common with the Richmond, Ohio, locaUty,
there is a remarkably close relation in the material from the two places.

"The replacement of the shale by the Morgan town sandstone has already been
commented upon in the description of that bed. This has taken place over much
of the eastern part of the State, and the fossiliferous shale is rendered very irregular
by numerous patches of coarse sandstone. The relation of these beds would indicate
that the shale and sandstone are of contemporaneous origin. The sandstone is
probably an estuarine or delta deposit, laid down at the same time that sedimenta-
tion of clays and silts was taking place in the neighboring salt-water lagoons.

"Toward the southern part of the State there is an increasing amount of red clay
and shale above the Ames limestone, and in many localities these beds, together with
the thin-bedded sandstone, constitute ahnost the entire Ames-Pittsburgh interval.

"^ K^Dndit, Bull. 17, Geol. Sur. Ohio, p. 27.

i> Scudder, Bull. U. S. Geological Survey No. 124, p. 12.

NORTH AMERICA AND THEIR VERTEBRATE FAUNA. 8^

" The Round Knob Formation. — This name is applied to the formation previously
called the Pittsburgh Red Shale by I. C. White. A typical section is shown in Madi-
son Township, Columbiana County, Ohio, near the cross-roads in section 15.

' ' The beds vary from structureless, purpHsh-red clay to deep red even-bedded
shale, which may alternate with bluish layers. The more sandy portions frequently
show ripple-marks and sun-cracks. Lenticular siderite concretions are common in
the bluish shales and nodules of limestone and hematite in the structureless red clay.
The hematite is in dense, reddish nuggets of submetallic lustre, which contain 55 to 60
per cent of iron and would be of value as iron ore were the quantity greater. Land-slips
are common in the Round Knob horizon ; hence the soft red clay becomes distributed
over a great vertical range, thus giving an appearance of considerable thickness.

"There has been much dispute as to the cause of the red color in the 'Coal
Measure' beds. That it is in the case of the Round Knob horizon original rather
than a secondary phenomenon due to the reactions of weathering is evident, since the
redness is persistent where the beds are hundreds of feet below the surface, as is shown
by drillings. Such colors are entirely wanting in the lower beds of the Pennsylva-
nian series, and appear near the middle of the Conemaugh for the first time. It is
true that reddish tints are seen in a few horizons in the lower third of the formation,
but these are largely secondary, or, in other words, the result of weathering, and only
appear at or near the outcrop. It is probable that the change in climate, together
with varied sources of supply of the sediments, are largely responsible for the red beds .

" The Ewing Limestone.^ — Beneath the Barton coal is clay and more or less lime-
stone in the form of nodular layers. The limestone is much more persistent than the
coal and is found nearly everywhere except in places where it has been eroded and
its horizon occupied by the sandstone. Ordinarily, there is only a nodular layer a
foot or so thick, or a single course of limestone less than 2 feet, but here and there
in the eastern part of the State are areas where the limestone attains a thickness of
5 to 10 feet and consists of a number of layers interlain with clay. * * *

"Fossils of types generally regarded as fresh-water are abundant in the Ewing
limestone. Spirorbis is the most numerous of these, and ostracod carapaces are next
in abundance. Fish-teeth are not uncommon and reptilian bones are also present.

"Along the lower Symmes Creek Valley, in Lawrence County, the Ewing lime-
stone is a gray rock in a single layer about 1 5 inches thick. An outcrop on the Alfred
Ward farm, near Getaway, was found 5 1 feet above the Cambridge limestone. In
many places to the north there is only red clay with nodular limestone in this hori-
zon, or frequently sandstone. In some localities the limestone is so ferruginous that
it has been dug for iron ore.

"A reptilian bone is reported from the same limestone in Harrison County, in a
railroad cut about i mile west of the village of Jewett."

It is evident, from the descriptions given by Dr. Condit of the Conemaugh
formation in Ohio, that the conditions there near the close of Carboniferous
were in many regards very similar to those of the western deposits and that
animal life there vi^ould have existed amidst almost identical surroundings.
This fact is further emphasized by the similarity in the shading of the lime-
stones into sandstones, as described by Condit : ''

"The sudden thinning of the non-marine limestones to the southward along
the Ohio outcrop is noteworthy. Both the Conemaugh and the Monongahela have

• Condit, Bull. No. 17, Geol. Surv. Ohio, p. 37.
*> Condit, Ibid., p. 250.

84 THE PERMO-CARBONIFEROUS RED BEDS OF

numerous non-fossiliferous limestone beds southward as far as Athens County, but
beyond that nearly all fail to appear, and in the same area there is a sudden increase
in the amount of red beds, thus forming an almost continuous series from the Cone-
maugh through the Monongahela uniting with those of the Dunkard."

On pages 250-260 Dr. Condit gives an account of the deposits of the Cone-
maugh formation which might be applied without change to many places in
the western Red Beds. He concludes that the beds were deposited in lagoons
or on deltas in a region with a rather arid climate which was occasionally
flooded by shallow and short-lived invasions of the sea. After comparing the
beds with those of the Mauch Chunk as described by Barrel, he concludes:

"The Permian of the West, characterized by bright colors and beds of gypsum,
is a still more striking iUustration of this kind (beds deposited as deltas in a semiarid
climate). While evidence of such pronounced aridity is lacking in the Permian
(Dunkard) beds of the Appalachian basin, still it is evident that conditions were
somewhat similar. It is believed that the appearance of the red color in the Cone-
maugh marks the beginning of the Permian. In southern Ohio, where the Monon-
gahela coals and limestones are scantily developed, the red beds are practically
continuous from the Conemaugh through the Monongahela, uniting with those of
the Dunkard."

The author has examined a fragment sent to him by Dr. Bownocker and
which is undoubtedly that of a fish. Unfortunately other fragments, upon
which the presence of amphibians and reptiles were determined, have been lost.

PENNSYLVANIA AND WEST VIRGINIA.

Fossil vertebrates closely related to those of Texas have been found near
Pittsburgh, Pennsylvania, in a shale just beneath the Ames limestone. The
beds in which these fossils were found are described by Raymond,^ the dis-
coverer, as follows:

"The bones are from the upper part of the formation which I. C. White has
named the Pittsburgh red shale (Geol. Survey West Virginia, vol. 2, p. 263). This
formation is usually from 100 to 125 feet thick in the vicinity and consists of red
clays and red and yellow sandstones. At the top there is a bed of almost structure-
less clay, which varies from 18 to 40 feet in thickness. At Pitcairn the clay is 37
feet thick, and the fossils were found 4 feet above the base of the clay. Three feet
above the base of the clay there is a layer of nodular limestone, and the teeth were
found lying on this layer where it projects from the bank on the roadside. The other
bones were all imbedded in the clay about i foot above the limestone. On the
Pittsburgh shale rests the Ames limestone, the youngest of the marine limestones in
the region. It is almost exactly in the middle of the Conemaugh series. It is 315
feet below the base of the Pittsburgh coal, and 695 feet below the base of the
Dunkard series (Permian). The Ames limestone is about 300 feet above the Free-
port coal (top of the Allegheny series)."

The Pittsburgh red shale is described by White :''

"As a rule the Friendsville coal, or, in its absence, the Ames limestone, rests
directly upon a soft red or purple shale, which, from its fine exposure along the grade

° In Case, Annals Carnegie Mus., vol. IV, Nos. Ill and iv, p. 234, 1908.
i* White, West Virginia Geol. Surv., vol. 11, pp. 263, 264, 1903.

NORTH AMERICA AND THEIR VERTEBRATE FAUNA. 85

lines of many railroads at Pittsburgh, has been named from that locality. Occa-
sionally there is some limy gray or red shale under the overlying coal or limestone,
as the case may be, and then comes another limestone bed quite different in color
and texture, and only slightly fossiliferous. The limestone is found occasionally in
Ohio, and has there been named the Ewing limestone by the Ohio geologists. It
has been seen at Huntington and a few other localities in West Virginia, but does
not appear to be very persistent. As a rule, the measures below the Ames limestone
and Friendsville coal consist of deep red and variegated shales, often marly and
containing nuggets of impure limestone and iron ore. The red beds extend from the
Ames limestone downward from 50 to 100 feet. Although red sediments may occur
at any horizon in the Conemaugh series, between the Mahoning sandstone and the
Pittsburgh coal, yet these near the middle of the series are the thickest, most per-
sistent and striking of all. It is this band of Pittsburgh red shale, 30 to 100 feet
thick, which makes such a conspicuous belt of red soil entirely across the State,
from the Pennsylvanian line at the north to the Kentucky border on the Big Sandy
River."

It is interesting to note that above the Conemaugh in the Monongahela
there is a change from limestone to red shale almost identical in character
with that which occurs in the Texas and Oklahoma regions.

MONONGAHELA BEDS.

In the north half of the State the Monongahela is nearly half limestone,
and no red shales.

"In passing southwest from Harrison, Taylor, and Lewis Counties, however,^
the limestones practically disappear, along with most of the coal beds, while red
shales come in as the limestones go out, apparently replacing the latter, and the
sandstones grow more massive than in the northern area, thus giving origin to a
rugged topography and less fertile soils.

' ' These rocks extend over a wide area along the Ohio River and for many miles
south of it, as far as the Great Kanawha, and in a narrow belt from that point to
the Big Sandy, where, in the center of the Appalachian trough, the lowest of these
beds passes into the air before reaching the Kentucky line.

"No marine fossils have ever been discovered in any of the limestones of the
Monongahela series, and everj'thing indicates that the deposits are of fresh-water
origin. The black slates always contain fish remains in the shape of scales and teeth,
but nothing is known of their affinities, because they have never been studied. The
water may have been estuarine and slightly brackish, but the minute Cyprian and
Estherian-like forms whose skeletons, mostly broken and pulverized, make up the
principal mass of the Monongahela series, testify clearly against their marine origin."

With regard to the significance of the Pittsburgh red shale and its verte-
brate fossils, it is well to quote Dr. I. C. White,'' who remarks:

"Viewed from the standpoint of change in physical conditions the proper place
for such dividing plane between the Conemaugh and Allegheny beds would be the
first general appearance of red rocks, near the horizon of the Bakerstown coal, about
IOC feet under the Ames or crinoidal limestone horizon. That a great physical
change took place soon after the deposition of the Mahoning sandstone rocks, the

"White, West Virginia Geol. Surv., vol. II, pp. 124, 125, 1903.
■■ White, West Virginia Geol. Surv., vol. 11, p. 226, 1903.

86 THE PERMO-CARBONIFEROUS RED BEDS OF

present basal members of the Concmaugh series, must be conceded, since no red
beds whatever are found from the base of the Pottsville up to the top of the Alle-
gheny, and none worth considering until after the epoch of the Upper Mahoning
sandstone.

' ' The sudden appearance or disappearance of red sediments after their absence
from a great thickness of strata is always accompanied by a great change in life
forms, and the present one is no exception. In fact, the invasion of red sediments
succeeding the Mahoning sandstone epoch of the Concmaugh may well be con-
sidered as the 'beginning of the end' of the true Coal Measures, both from a litho-
logical as well as a biological standpoint, and hence it is possible that the best
classification, aside from the convenience of the geologist, would leave the Mahoning
sandstone in the Coal Measures, and place the rest of the Concmaugh, as well as the
Monongahela series above, in the Permo-Carboniferous. This reference is also
confirmed by the character of the fauna and flora, both of which contain many forms
that characterize the Permo-Carboniferous beds of Kansas and the West, as may
be seen in the lists published on a subsequent page under the detailed description
of the principal Concmaugh strata."

PRINCE EDWARD ISLAND AND NOVA SCOTIA.

The age of the red rocks in Prince Edward Island, adjoining portions of
Nova Scotia and New Brunswick, was, by error in the interpretation of the
fossil reptile Bathygnatlms, by Cope, fixed as Triassic. They are now defi-
nitely known to be Permian or Permo-Carboniferous. Russell "^ has summa-
rized the evidence for the Triassic age of the beds in Prince Edward Island^
and has shown that there is no reason to believe Triassic to be present:

"Conclusions. — The absence of Newark fossils in the rocks of Prince Edward
Island; the close lithological similarity of the beds in the upper and lower portions
of the sections there exposed, the lower rocks being Permo-Carboniferous; and the
lithological difference of the rocks from the sandstone and shales of the Newark
system, seem to be sufificient ground for not considering any portion of the stratified
rocks of Prince Edward Island as belonging to the Newark system."

Huene'' and Case'' have shown that Bathygnathus boreal is is a Permo-
Carboniferous reptile closely related to Dimetrodon.

Matthews'* has given the following account of the deposits in Prince
Edward Island, which shows clearly the similarity in the conditions of deposi-
tion to those which prevailed during the formation of the Red Beds in western
North America :

"GEOLOGICAL CYCLES IN MARITIME PROVINCES.
"Carboniferous Cycle.

"* * * The millstone grit is essentially a part of the Coal Measures, but by
the greater prevalence of red sandstones and shales shows a relation in its climate
and conditions to the underlying Lower Carboniferous series.

» Russell, U. S. Geol. Survey Bull. No. 85. Correlation Papers— The Newark System, chap, in, p. 25.

'' Huene, Neues Jahrb. fur G. M. u. P., Beilage Bd., 1905, pp. 321-353.

" Case, Science, n. s., vol. xxii, 1905, p. 52.

<■ Matthews, Roy. Soc. Canada, Proc. and Trans., vol. 11, sec. iv, p. 121, 190S.

NORTH AMERICA AND THEIR VERTEBRATE FAUNA. 87

"Permian Subcycle.

"The rocks of this period * * * are largely spread in Prince Edward Island.
Much of the phenomena of this time are beyond our observation, as the sediments
of the period are, to a great extent, concealed beneath the waters of the Gulf of St.
Lawrence.

"The terrane begins with a conglomerate well shown near Pictou, in Nova
Scotia, and extending thence along the northern shores of Nova Scotia into New
Brunswick. Mr. Fletcher's account'' of the strata of this terrane recalls in many
respects the conditions and aspect of the Upper Devonian rocks of this region. The
great preponderance of red shales and red sandstones, the prevalence of plant re-
mains in many beds, the occasional presence of nodular or 'botryoid' limestones,
all suggest deposits which may have been laid down in a comparatively dry climate.
* * * They suggest that the Carboniferous plain * * * was now reduced in area
to a tract including the present southern shallows of the Gulf of St. Lawrence * * *
on this extended plain, with rivers entering it from the west and south, would have
been spread out the red sands and muds which now form the bulk of the Permian
deposits of Acadia."

In his description of the Triassic cycle, in the region around the Bay of
Fundy, Matthews, after describing the prevalence of volcanic activity,
divides the sediments into three groups:

The lowest is composed of "bright red sandstones with a cement more
or less calcareous, well laminated, and often showing oblique lamination."
' * * * A drier and probably colder climate" prevailed at this time.

The second group shows a "sudden transition to coarse pebbles," such
as those of a shingle beach, "often without a matrix," except by secondary
infiltration.

The third group is made up of sandstones and shales, mostly reddish-
brown, with some gray sandstones.

This last cycle may be Jura-Triassic. There are no data yet for deter-
mining the exact time limit.

» Fletcher, Can. Gaol. Surv., vol. 5, n. s., part 2, rep. P., p. 108.

CHAPTER V.

GEOGRAPHY OF NORTH AMERICA AT THE CLOSE OF PERMO-

CARBONIFEROUS.

The surface of the United States east of Ozarkia was largely free from an
epicontinental sea in the closing period of the Paleozoic. Schuchert,^ in his
chart of the submergences, shows a decided retreat of the sea, beginning at
the close of the Pottsville and continued until the close of the Upper Permian,
when it was at its maximum. In his chart of formations, opposite page 556,
he shows Permo-Carbonifcrous deposits in the bituminous region of Penn-
sylvania, the northern Appalachian region, Ohio, Kansas, Iowa, Oklahoma,
and central and trans-Pecos Texas.

Ulrich, in his Revision of the Paleozoic System, page 343, shows an ele-
vation at the close of the Pennsylvanian and a withdrawal of the Gulf inva-
sion which formed the Permo-Carboniferous limestones of eastern Kansas,
Oklahoma, and Nebraska. It is well recognized that in a general way the
withdrawal of the seas of upper Pennsylvanian time was by a gradual uplift
in the northeast which forced the waters toward the southwest, until the
last stand was made in the Texas-Oklahoma-Kansas region within the limits
of the Wreford and equivalent limestones.'' On the west this sea was bor-
dered by the great fiat, generally dry but with many pools, some of large
size, crossed or watered by streams and subject to short-lived inundations
of ocean water in the southwest (Clear Fork limestones). The border be-
tween the sea and the flat can only be indicated very broadly, and probably
never was a stable line; slight changes in level induced wide advances and
retreats of the strand lime. Broadly speaking, the border was where the
limestones shade into red deposits toward the west, as indicated above (p. 12).
On the northern part of the flat rose the precursors of the Arbuckle Hills,
and farther to the west those of the Wichita Mountains, at that time masses
of considerable magnitude.

Gordon *= has given the following account of the sedimentation on this
flat in Texas, which is equally applicable to the beds in Oklahoma :

"Conditions of Sedimc7iiation.— The character of the sedimentation and the
contents of the strata in the 'Red Beds ' area suggest that the region was a tidal flat
or a low, swampy area subject to overflow and adjoining the open area ^vhich lay
toward the south and west. This view is maintained by Case, who states that 'the
whole formation seems to be very clearly the result of deposition, either in the form
of a wide delta or in very shallow water. ' He adds, further, that ' the remains which

" Schuchert, Paleogeography of North America, chart of submergences and emergences and map of
Lower Permian.

i* Girty, Outlines of Geological History, chap. VI, pp. 126, 127.

"Gordon, U. S. Geological Survey, Water Supply and Irrigation Paper No. 317, pp. 26. 27, 1913.

NORTH AMERICA AND THEIR VERTEBRATE FAUNA. 89

are foimd on or in the sand layers were evidently washed there by currents from a
distant shore, and they are generally more or less imperfect, having been dispersed
by the action of the current or by predatory animals, while those found in clay
were evidently animals which mired down on wide mud flats or were drifted out
on the surface of the stagnant lagoons.'

The clays and the sandstones are separated in some places by unconformities
which are considered by Case to be the result of currents that eroded channels in
the clay in which the sands were afterward deposited. They do not represent appar-
ently any considerable time interval between the two deposits. Moreover, the
conglomerates containing concretions of ferruginous clay are evidently additional
indications of transitory currents in an ordinarily quiet lagoon or over the tidal flats
of a wide delta.

The red sediments evidently had their source in the degradation of the Wichita
Mountains, which lie directly to the north of this region, in Oldahoma. These
mountains were uplifted during or at the close of the Pennsylvanian epoch and are
now, together with their accompanying elevations on the east, the Arbuckle Morm-
tains, partly buried in the sediments they have furnished.

The fact that in this region, as shown by their outcrop toward the east and by
the strata penetrated in deep wells, the upper beds of the Cisco formation consist
of sediments corresponding in character to those of the Wichita formation, suggests
that mud fiats may have characterized the closing stages of the Pennsylvanian epoch
in this region.

"Thickness. — In Shackelford County the thickness of the Wichita formation is
estimated to be i,ooo to 1,200 feet. Two-thirds or more of the formation consists
of blue clays and shales. Farther south, in the vicinity of Colorado River, lime-
stones constitute the major part of the formation. To the north from Shackelford
County the calcareous sediments diminish, and before reaching the Oklahoma
border they practically disappear. No reliable estimate can be made of the thick-
ness of the formation in this part of the region, though it is probably not less than
1,500 feet."

South of the north line of Oklahoma the Permo- Carboniferous beds dis-
appear beneath the Triassic at the eastern side of the Staked Plains (plate 13,
fig. i). On the western side of the Staked Plains Permo-Carboniferous beds
appear in the valley of the Pecos River, according to Beede (see p. 58), but
they are absent in the latitude of Tucumcari, Montoya, and Las Vegas. Ap-
parently the condition of river and delta deposits extended across the Staked
Plains and west to the Rocky Mountains south of this latitude as it did to
the north, but here there is no certainty that it reached to the mountains.

As outlined above (pp. 62-71), the Red Beds of Permo-Carboniferous age
in the northern part of the Plains Province shade into limestones toward the
east and north, indicating the western edge of the open-sea waters. There
seems little doubt that the northern Red Beds are connected with those in
the south beneath the later deposits, and that both are parts of one great
area of deposition.

Beyond the Rocky Mountains red bed conditions prevailed along the
Chama River in Rio Arriba County, New Mexico, and probably much farther
to the north and south, though this may have been in a slightly earlier time.

go THE PERMO-CARBONIFEROUS RED BEDS OF

The deposits of Rio Amba County certainly extend west under the Creta-
ceous and Tertiary of northwestern New ]\Iexico into Arizona, where they
reappear as the Moencopie and Kanab (?). Permian or Pcrmo-Carbonifer-
ous invertebrate fossils have been found in limestones in northern Utah and
as far north as the Bighorn Mountains. The limestones are apparently con-
nected with the Red Beds of New Mexico and Arizona in somewhat the same
way as the limestones of the Plains Province are connected with the Red Beds
there. It is possible, even probable, that the deposits of the Basin Province
were formed somewhat earlier than those of the Plains Province, but both
were laid down within the limits of the Permo-Carboniferous.

I am inclined to suggest some changes in Schuchert's paleogeographic
map of the lower Permian (Permo-Carboniferous). It is increasingly evident
from a study of the Red Beds that there was a land-mass of great size and
height between the two areas of land deposits on the eastern and western
sides of the Rocky Movmtains. No attempt has been made in the present
paper to determine the amount of material included in the portion of the
Red Beds considered as Permo-Carboniferous in age, but the briefest inspec-
tion reveals an amount of material so great that it can have originated only
in the degradation of a mass of land far larger than the present igneous and
early Paleozoic rocks in the Rocky Mountains, and if we add to the Permo-
Carboniferous deposits those of Pennsylvanian, Triassic, and Jurassic age
which are with difficulty distinguished or are evidently the result of a con-
tinuation of similar conditions, the mass of the land later degraded assumes
majestic proportions, for it is easily demonstrable that the source of by far
the largest proportion of the Red Beds material was the land-mass on the
present site of the Rocky Mountains.

In the Plains Province the conditions for land deposition shaded into
limestone-forming seas to the east and northeast; that these seas were nar-
row from east to west there can be no doubt, because of the high land of
Ozarkia and the land deposits in Iowa, which show an elevation, but they
were sufficiently broad to prevent the transportation of any material from
the eastern land to the flats where the Red Beds were formed.

The outline of the Red Beds west of the Rocky Mountains is not yet
clearly made out, but the land deposits are more closely associated with
limestones both vertically and horizontally, indicating shorter duration and
lesser extent, with a closer approximation of the ocean waters to the great
land-mass than in the east.

The Wichita Mountains and the Arbuckle Hills were only subsidiary
sources of .supply. It is probable that much of the material of the Red Beds
in Arizona came from sources not yet clearly imagined; however, there is
evidence that the Rico was deposited near the source of the material, and the
distance from Ouray to the Grand Canyon is not greater than from the Front
Ranges of the Rockies to some localities of Red Beds in Kansas.

NORTH AMERICA AND THEIR VERTEBRATE FAUNA.

The two provinces of Red Beds as outlined in this paper can only be con-
sidered as great flood-plains or deltas (in Barrel's broad interpretation of
that word).

East of the Permian limestones of Texas, Oklahoma, Kansas, and Ne-
braska the surface of North America was probably very largely out of water;
the few evidences of river channels, local pools, etc., are sufficiently meager,
but by their very meagerness indicate the large extent of land surface. Had
there been deposits of any extent from marine or fresh waters some traces
would have tmdoubtedly remained to us, for the eastern half of the Missis-
sippi Valley has been a region of comparatively slight degradation since the
close of the Paleozoic.

CHAPTER VI.

AGE OF THE RED BEDS.

The age of the Red Beds north of Oklahoma, in Kansas, was long in
doubt, due to the absence of fossils. At first considered as Carboniferous,
or Permian, by the earliest writers, they were later referred to the Cretaceous,
and finally to the Triassic and Upper Permian. The history of the various
discussions of the age of these beds has been summarized by Cragin "* and
Prosser,'' and need not be reviewed here. The final conclusion of those who
have worked latest upon the Kansas beds is that they are of the same age as
the Texas-Oklahoma beds, i. e., Permian or Pcrmo-Carboniferous. This con-
clusion has been reached because of the more or less complete tracing of the
beds into Oklahoma and even Texas, and the finding of Permo-Carbonifer-
ous fossils in the Red Beds of Kansas.

With regard to the Texas Red Beds the opinion is less consistent. Cope,
and, following him, later writers, considered the vertebrate fauna as indicating
the Permian age of the beds. Case," in 1908, reported on the fossils found in
Upper Pennsylvanian beds of Pennsylvania, and this led him to a recon-
sideration of the value of the evidence of the vertebrate fauna of Texas for
the Permian age of the Red Beds. His results were purely negative,'' but a
single genus common to America and Europe being restricted to the Permian
of Europe. Later he discovered Spirifer rockymontana above beds carrying
Permo-Carboniferous vertebrates in New Mexico. This is a Pennsylvanian
form not occurring above that horizon (Schuchert) and perhaps limited to
the Allegheny (Girty, letter to the author). These facts have led Williston
and Case " to the conclusion that the vertebrate beds of Texas, Oklahoma,
and New Mexico are to be considered on the border-line between the Permian
and Carboniferous.

Taff ^ places the Permian {sic) of Texas above the Cisco. "This group
(the Albany) is succeeded by the Permian, which overlaps upon the Cisco
division between the Brazos and the Red River."

Udden*^ says the Wichita "rests on the Cisco." And again, page 31:
"Evidently the geographic conditions prevailing during the deposition of the
Wichita beds were different from those existing during the making of the
Cisco."

" Cragin, Colorado College Studies, vol. VI, pp. 2 and 396.

'' Prosscr, Kansas University Geological Survey, vol. II, pp. 55 and 97, 1897.

" Case, Ann. Carnegie Mus., vol. iv, Nos. 3 and 4, pp. 23 and 41.

■1 Case, Jour. Geol., vol. 16, No. 6, pp. 572-580, 1908.

" Williston and Case, Jour. Geol., vol. xx, No. i, pp. 1-12, 1912.

' Taff, 22 Ann. Rpt. U. S. Geological Survey, part 3, p. 402, 1902.

s Udden, Bull. University of Texas No. 246, p. 1, 1912.

NORTH AMERICA AND THEIR VERTEBRATE FAUNA. 93

Gordon " says the Cisco is not the same as the Wichita and speaks of the
separation between them.

David White ^ is convinced from paleobotanical evidence that the Texas
beds are Lovi^er Permian. After giving floral lists from Texas, Oklahoma,
and Kansas and pointing out their strong Permian content, he says:

"The very incomplete collections of fossil plants from the Wichita formation
in Texas, from its supposedly approximate equivalents in Oklahoma, from the Chase
and Sumner groups in Kansas, and from the great series of undifferentiated 'Red
Beds' in the Rocky Mountain region of southern Colorado, showed a mixed flora
embracing: (i) mainly representatives of the Permian flora of western Europe,
and including many types not previously known in North America; (2) a smaller
portion peculiar to the Gigantoptcris association in south-central and southwestern
China; and (3) several types apparently identical with, or very close to, forms
hitherto known only in the Permian or the Uralian region.

"The distribution of the floral elements indicates that the western European,
or cosmopolitan, elements of the flora migrated between North America and Europe,
presumably by the same general northeastern route as that followed by their Penn-
sylvanian predecessors, while the distinctly Chinese types must have come to Texas
and Oklahoma by the north Pacific (Alaskan) route, by which the related Uralian
forms may also have migrated. Since the land migration of the Chinese types
could hardly have been accomplished vvithout the aid of essential continuity of
environmental conditions, and since it is probable that the Gigantoptcris elements
lived under climatic conditions mainly similar in both Texas and China, the conclu-
sion appears justified that the climatic province under which they thrived in Asia
extended to western North America, and that it included the region of north Pacific
migration. The mingling of western European species with Gigantoptcris in the
southwestern 'Red Beds' is construed to indicate that this region was probably on
the eastern border of the Gigantoptcris province."

Beede says'' "the Permian age of the beds (in Oklahoma) has been pretty
well confirmed."

LIMITING HORIZONS OF THE VERTEBRATE FAUNA.

The author of this paper has no intention of making any effort to
determine exactly the horizon of the vertebrates here called Permo-Carbon-
iferous. The exact valuation of these beds must be accomplished by the
workers in invertebrate paleontology, aided by detailed comparison of the
American vertebrates with those of the rest of the world, which would be
quite beyond the limits of this work and must be reserved for future papers.

Prosser, Beede, Girty, Gould, Schuchcrt, and others have attempted to
determine the horizon of the beds from invertebrate fossils and have not
reached concordant results. All that is attempted here is to locate in
accepted terms the upper and lower limits of the beds which represent the
time of the vertebrate fauna here discussed. For this purpose the lower limit
of the Permo-Carboniferous beds is tentatively drawn at the base of the

' Gordon, with Girty and White, Jour. Gcol., vol. xix. No. 2, pp. 119 ,120, 191 1.
''White, Proc. U. S. Nat. Mus., vol. 41, p. 513, 1912.
'Beede, Oklahoma Geological Survey, Bull. 21, p. 37, 1914.

94 THE PERMO-CARBONIFEROUS RED BEDS OF

Wreford limestone, Kansas (Beede " in a recent paper draws it at the base of
the Neva limestone); Enid, Oklahoma; Wichita, Texas; Manzano (?), New
Mexico; Moencopie and Kanab (Aubrey), Arizona; Cutler and Lykins, Colo-
rado; Upper Weber, Utah; Upper Embar and Opechee, Wyoming; Opechee,
South Dakota ; Merom sandstone, Indiana ; Ames limestone, Pennsylvania.
The charts opposite pages 64 and 66 (plates 2 and 3) from Darton show the
relations of most of the Red Beds in the northern part of the Plains Province.

The lower limit of the fauna is confessedly vague and shadowy, passing
far down into the Pennsylvanian. The Pennsylvanian amphibians described
by Moodie in numerous papers are so close to those occurring in association
with the Permo-Carboniferous forms from Texas that it is evidently a case
of overlapping, and the only recognizable line is that where the first reptile
occurs. It is, of course, probable that the reptiles occurred at lower horizons.
In 19 10 Moodie found a form near Cricotus in the Mazon Creek shales.*"
These shales are near the base of the Allegheny (or even the top of Pottsville).
David White regards them as equivalents of Coal No. 2 of Illinois (Morris and
Braidwood coals of the Clarion). They are all regarded by him as having
close relationship with the Cherokee of Henry County, Missouri, at the base
of the Allegheny."

The Linton coal, from which comes Eosauravus copei Williston {Isodectes
panctulatus, originally Tiiditanus piinctalatas, Cope), belongs in the Upper
Freeport coal (Coal No. 6), and is referred by Prosser "^ to a position near the
top of the Allegheny. The old coal mine (Diamond coal mine) located near
Linton, Jefferson County, Ohio, from which numerous amphibians and a few
reptiles have been collected, has been abandoned, and further collections
are impossible. Williston " and Moodie ^ have described the genus Eosaur-
avus, giving figures, and demonstrated its reptilian nature.

The earliest amphibians definitely comparable to the Texas fauna are
those from the Pittsburgh red shale of Pennsylvania. The Pittsburgh red
shale lies 300 feet above the Freeport and 695 or more feet below the base
of the Dunkard. Dr. I. C. White ^ has remarked upon the significance of a
red formation above the limestone, in describing the dividing-line between
the Conemaugh and the Allegheny, which has been placed at the Upper
Freeport coal. He says:

' ' Viewed from the standpoint of physical conditions, the proper place for such
a dividing plane between the Conemaugh and the Allegheny beds would be the first
appearance of red rocks near the horizon of the Bakerstown coal, about 100 feet
under the Ames or crinoidal limestone horizon. That a great physical change took
place soon after the deposition of the Mahoning sandstone rock, the present basal

"Beede, Oklahoma Geol. Surv., Bull. 21, 1914.

>> Moodie, So., vol. 30, 1910, p. 233.

'White, Bull. 211, U. S. Geological Survey, p. in.

'^ Prosser, Jour. Geol., vol. xi, p. 519 et seq.

" Williston, Jour. Geol., vol. xvi. No. 5, 1908, pp. 395-400.

' Moodie, Proc. U. S. Nat. Mus., vol. 37, p. 11, 1909.

e White, West Virginia Geol. Survey, vol. 11, p. 226, 1903.

NORTH AMERICA AND THEIR VERTEBRATE FAUNA. 95

member of the Conemaugh series, must be conceded, since no red beds whatever
are found from the base of the Pottsville up to the top of the Allegheny, and none
worth considering until after the epoch of the Upper Mahoning sandstone.

The sudden appearance or disappearance of red sediments after their absence
from a great thickness of strata is always accompanied by a great change in forms,
and the present one is no exception. In fact, the invasion of the red sediments suc-
ceeding the Mahoning sandstone epoch of the Conemaugh may well be considered
as the 'beginning of the end' of the true Coal Measures, both from a lithological
as well as a biological standpoint, and hence it is possible that the best classification,
aside from the convenience of the geologist, would leave the Mahoning sandstone
in the Coal Measures, and place the rest of the Conemaugh, as well as the Mononga-
hela series above, in the Permo-Carboniferous. This reference is also confirmed by
the character of the fauna and flora, both of which contain many forms that charac-
terize the Permo-Carboniferous beds of Kansas and the West, as may be seen in the
lists published on a subsequent page under the detailed description of the principal
Conemaugh strata."

If this sudden change has the significance attributed to it by White, we
are justified in regarding the appearance of the forms beneath the Ames
limestone as marking the advent of a new fauna, by evolution or migration,
which apparently spread over the whole of North America, as evidenced by
its discovery in localities from Prince Edward Island to New Mexico. This
fauna, so far as we know, appeared at an earlier date in the eastern part of
North America than in the western, suggesting the general route of immigra-
tion or spreading from its point of inception.

The red shale series mentioned by White ^ is the equivalent of the Pitts-
burgh Red Shale. The Ames limestone Hes just above it. This last is
"almost exactly the middle of the Conemaugh series, 315 feet below the base
of the Pittsburgh coal, and 695 feet below the base of the Dunkard series
(Permian) . The Ames limestone is about 300 feet above the Freeport coal
(top of the Allegheny series)." (Statement in a letter from Dr. Raymond.)
It is evident, then, that the lower horizon of the reptiles is carried at least
into the Allegheny at Linton.

The exact age of the beds in Illinois and Prince Edward Island, in which
similar forms occur, is not yet determined.

The limit recognized for the Permo-Carboniferous fauna is, then, from
the Pittsburgh Red Shales to the top of the Clear Fork. The stratigraphic
extent of the space delimited it is impossible to state, as there is no direct
correlation of the eastern and western beds possible, but it may be roughly
stated as from the middle of the Conemaugh to near the top of the Permo-
Carboniferous. The limits of the fauna in America, however, are not those
of Europe; the fauna was there continued into the Triassic.

* White, Geol. Surv. West Virginia, vol. ii, p. 263.

THE PERMO-CARBONIFEROUS RED BEDS OF

PERMO-CARBONIFEROUS VERTEBRATE FAUNA NOW KNOWN.

Table i classifies the Permo-Carboniferous fauna as now known, with
their geographical and geological distribution.

Table i.

Texas.

Oklahoma
(Enid).

Kansas
(Carri-
on (?)).

New
Mexico T
(?). ,

(Upper 1 (u r

Prince

5dward

Island

(?)•

Wichita.

Clear
Fork.

«>"»°)- ! vanian).

PISCES.
Selachii.

X
X

X'
X

ICTHYOTOMI.

Pleuracanthus quadriseriatus Cope

XP.C.

X
X

X
X'

X P.C.T.

platyptemus

ICTHYODORULITES.

Ctenacanthus amblyxiphias Cope

Anodontacanthus americanus Hussakof . .

DiPNEUSTI.

X Or.

X
X

fxxxx XX XX XX X

X'
X'
X'
X'

XP.C.

Crossopterygii,

X'
X'
X'
X

"x "

X
X
X

ACTINOPTERI.

(?) Pyritocephalus sp. Fritsch

Platysomus palmaris Cope

AMPHIBIA.

Order STEGOCEPHALIA.

Suborder MICROSAURIA (?).

Family Diplocaulidae:

Diplocaulus salamandroides Cope

X P.C.
X P.C, Or.. T.

X?
X

Suborder TEMNOSPONDYLI.

RHACHITOMOUS DIVISION.

Family Eryopidae:

X P.C, N., T.

X
X

XN.

X
X

—

NORTH AMERICA AND THEIR VERTEBRATE FAUNA.

Table i. — Continued.

Texas.

Oklahoma
(Enid).

Kansas
(Garri-
son (?)).

New
Mexico

Illinois
{Upper
Pennsyl-
vanian).

Pennsyl-
vania

Prince

Wichita.

Clear
Fork.

(Upper
Pennsyl-
vanian).

Island

AMPHIBIA— Continued.

Family Trimerorhachidse:

X
X

X'Or.

bilobatus Cope

leptorhynchus Case . .

X N.

X
X

alleni Case

conchigerus Cope . .

X
X

X
X
X

X
X

Family Dissorhophidce :

Alegeinosaurus aphthitos Case

Family Aspidosauridcc:

glnscocki Case

apicalis Cope

X T.

novomexicanus Williston
Broiliellus texensis Williston

X
X

Family Trematopsidae:

Order URODELA.

Suborder .

Family Lysorophida; :

Suborder .

Family Crossotelida: :

Crossotelos annulatus Case . . .

X Or.

INCERT^ SEDIS.

Suborder GYMNARTHRIA.

Family Gymnarthrida;:

GjTTinarthrus willoughbyi Case. .

X
X

EMBOLOMEROUS DIVISION.

Family Cricotidae:

X Or., T.

gibsonii Cope

X
X

heteroclitus Cope

crassidiscus Cope

XOr.

Chenoprosopus milleri Alehl

REPTILIA.

Order COTYLOSAURIA.
Suborder DIADECTOSAURIA.

Family Diadectidae:

phaseolinus Cope X

molaris Cope X

X 1 XT.

fissus Cope .

X
X

latibuccatus Cooe

(Nothodon) lentus Marsh.

maximus Case '^'

XP.C.

X
X

t '

THE PERMO-CARBONIFEROUS RED BEDS OF

Table i.^ Continued.

Texas.

Oklahoma
(Enid).

Kansas
(Garri-
son(?)).

New

Mexico

(?)■

Illinois
(Upper

?ennsyl-
vania
(Upper
?ennsyl-
vanian).

Prince
Edward

Wichita.

Clear
Fork.

Pennsyl-
vanian).

Island

REPTILIA— Continued.
Family Diadectidae.— Continued.

Family Bolosaurida;:

X
X

INCERT^ SEDIS.

Chamasaurus dolichognathus Williston *

Suborder PAREIASAURIA.

Family Pariotichidse:

X
X
X

Family Captorhinida:::

X ?, P.C.

X
X

Family Labidosauridas:

XP.C.

Family Limnoscelidae:

Family Seymouriida^:

X
X

X'
X

X Or.

INCERT^ SEDIS.

X Or. ..

X
X

' "x "

X
X

Suborder PANTYLOSAURIA.

Order THEROMORA.
Suborder PELYCOSAURIA.
Family Poliosauridffi :

XP.C.

X
X

X
X
X
X

Scoliomus puercensis Williston & Case
Family Clepsydropidffi :(Sphenacodontidae

X
X'

X
X
X
X
X

X P.C.

X
X

XP.CT.

* In press.

NORTH AMERICA AND THEIR VERTEBRATE FAUNA.

Table i.—

-Continued.

Texas.

Oklahoma
(Enid).

Ill

M„.^ Illinois
T^^'7 (Unner

Pennsyl-
vania
(Upper
Pennsyl-
vanian).

Prince
Edward
Island

Wichita.

Clear
Fork.

(?).

Pennsyl-
vanian).

INCERT^ SEDIS.— Continued.

Family Clepsydropidse: (Splienacodon-
tidae). — Continued.
Dimetrodon longiramus Case

X
X
X
X

macrospondylus Cope

platycentrus Case

.. !

Arribasaurus navajovicus Case

Tetraceratops insignis Matthew

Bathygnathus borealis Leidy

X' 1 V'

Mycterosaurus longiceps Williston * . . .
Glaucosaurus megalops Williston * . . . .

INCERT^ SEDIS.
ArcheobcUus vellicatus Cope

X
X

Family Areoscclida;:

Areoscelis gracilis Williston

X
X'

X
X
X

? Embolophorus frittilus Cope

Suborder EDAPHOSAURIA.

Family Edaphosauridse:

Edaphosaurus claviger Cope

X
X
X

X ?, Or., T.

cruciger Cope

pogonias (?) Cope

novomexicanus Willis-
ton & Case

raymondi Case

Suborder CASEASAURIA.

Family Caseida;:

Casea broilii Williston

X
X

Trichasaurus texensis Williston

INCERT^ SEDIS.

Goniocephalus willistoni Broili

Platyhistrix rugosus Case

*In press.
Note. — A prime mark (') placed by an X in this table indicates that it is possible that the specimen
came from the formation indicated, but that the records are imperfect. Where such a mark is placed by
the X in both the Clear Fork and the Wichita it indicates that the specimen came from, possibly, both of the
formations, but that the records are imperfect. P.C. = Pond Creek; Or. = Orlando; N. =Nardin; T. =Taylor
(2 miles southwest) ; ?= species uncertain.

CHAPTER VII.

ANALYSIS OF THE FAUNA.

In attempting an analysis of the Permo-Carboniferous vertebrate fauna
of North America, several facts become at once apparent which are in entire
accordance with evidence furnished by the beds in which the remains are
preserved.

There are )w forms which can be called distinctly marine.

As is well known, there are several sliarks which live in brackish, or even
fresh, water (see p. 124). The dipnoans and crossopterygians are inhabitants
of fresh water. Correlatively it may be stated that bones of sharks and
fishes do not occur in the limestones of the Clear Fork beds associated with
marine invertebrates. In only a few places have bones of fishes or other
vertebrates been found in limestones, and these are indeterminate fragments
which might have been carried a long distance.

Amphibians are generally able to live only in fresh water, salt water,
even when very dilute, commonly preventing development of the egg, and,
in more concentrated form, being fatal to the individual. A recent paper
by Pearse," however, reports the development of tadpoles in the waters of
a small creek entering Manila Bay. Three analyses of the water of this
creek give respectively 2.6, 2.1, and i.i per cent sodium chloride. Normally
0.6 per cent of sodium chloride is sufficient to prevent gastrulation of the egg.^
The waters of this creek were subject to tidal influence, and so the quantity
of the sodium chloride undoubtedly varied, but it can hardly be supposed
that it was ever below 0.6 per cent for any length of time.

Darwin" mentions that the tadpoles of certain frogs develop in sea-water
on the coast of India.

Carl Wiman'* in 1 9 1 1 reported the discovery of some long-snouted forms
in the Trias of Spitzbergen, which he considered as marine amphibians.
Cossman has suggested, however, that these are possibly reptilian.

Amphibians of to-day live in waters which contain an abundance of
dissolved salts, mostly calcium carbonate: as Proteus of the Austrian caverns,
and Cryptobranchus, etc., of the streams of the Mississippi Valley.

These facts lend support, so far as they go, to the suggestion which has
freqiiently been made that the ancient amphibians may have been far more
tolerant to the effect of sea-water than living forms. On the other hand is
the fact that amphibian remains have never been found associated with
marine invertebrates in a way to suggest that they lived in the same waters.

" Pearse, Philippine Journal of Science, vol. VI, No. 4, sec. D.

■■ Glaser, Science, vol. 36, p. 679.

' Darwin, Origin of the Species, 6th ed., p. 414.

"* Wiman, Bull. GeoL, Upsala, 1911, vol. ix.

NORTH AMERICA AND THEIR VERTEBRATE FAUNA. lOI

The weight of evidence is still very strongly in favor of the belief that amphib-
ians were as severely restricted to fresh water in the past as at present.

An abundance of amphibian remains shows almost conclusively that the
beds in which they occur were deposited in freshwater, or so near to a land with
bodies of fresh water that the remains could be easily swept out and deposited
with the material of the beds after death. The occurrence of such mollusciv-
orous animals as Diadcctes, Edaphosaiirits, and Puntyliis suggests the proxim-
ity of a shoreline with an abundant food-supply, but this need not have been
the edge of a salt-water sea, as there were in all probability numerous fresh-
water and even land molluscs which could have supported these animals.

No reptiles have as yet been discovered which shoiv a great advance in special-
ization toward an aquatic life.

The majority of forms are such as would lurk in secure places in the waters
of lakes, swamps, or streams, or hide in the vegetation which lined their banks.
Undoubtedly many of them swam freely at times, but none ever approached
the high degree of aquatic specialization exhibited in the Plesiosaurs, Icthyo-
saurs, or Mosasaurs. Some ranged more freely in the open, or in thick wood-
lands and underbrush, or like Casea, perhaps, may have lived in bare and
arid places, or have been like Areoscelis, at home in the branches of the tree-
like vegetation.

The fauna was one of estuaries, swamps, lagoons, alluvial plains, and
open or covered woodlands. There is no evidence of even semipelagic forms
unless it be the genus Cricotus and possibly Chenoprosopus; and no certain
evidence of any forms which inhabited a marine riparian.

FOOD HABITS AS INDICATED BY THE TEETH.

The fishes, so far as can be learned from the form of the teeth, were very
similar in habits to living forms in the same groups.

The amphibians show the universal carnivorous dentition ; the teeth in all
are simple, conical, grasping organs with slight power of mastication.

In some, as Eryops, Cacops, Trematops, etc., there were large tusks on the
vomers, palatines, and maxillaries, which served as accessory grasping organs,
indicating the habit of seizing more or less powerful and active prey. In
other forms the teeth form a single, uniform series in both the upper and lower
jaws. The larger forms were undoubtedly voracious feeders, and carried
destruction into the ranks of the smaller and more helpless creatures. The
bones of fishes, smaller amphibians and reptiles are abundant in the copro-
lites, a considerable proportion of which must be from the larger Amphibia.

The feeble dentition of L3'5oro/>/M<5, Diplocaulus, Cardiocephalus, etc., shows
that they were confined to a diet of smaller and soft-bodied animals, worms,
insect larvse, and unprotected crustaceans and molluscs, with such dead bodies
as might be discovered, and, perhaps, even some forms of vegetation.

Among the reptiles a greater variety of food habits is indicated by the
character of the teeth, but so far no form has been discovered which can be

I02 THE PERMO-CARBONIFEROUS RED BEDS OP

reckoned as purely, or even largely, herbivorous. Some are clearly pure car-
nivores; others may have included some portion of vegetation in a diet
composed largely of hard-shelled molluscs.

The synoptic statement below will give an idea of the form of the
teeth in the different groups and their supposed food habits ; but besides the
forms mentioned there were numerous smaller reptiles, with sharp, conical
teeth, which can only have been carnivorous or insectivorous.

Pei.ycosauria.
Poliosaurirla;.
Clepsydropida; (Sphenacodontidoc).

All with sharp and conical teeth, which were recurved in some forms, and with more or less sharp
and even serrate cutting-edges. Maxillary and incisor tusks enlarged in certain forms, some-
times to relatively great size. Raptorial; carnivorous.
Edaphosauria.

Edaphosaurida;.

Teeth on the edges of the jaws sharp and conical; incisor teeth somewhat chisel-shaped; strong
crushing-teeth developed on plates on the dentaries, pterygoids, and palatines. The crushing-
teetli with short, sharp points when young, but wearing blunt or flat. Molluscivorous (duro-
phagous).

COTYLOSAURIA.

Limnoscelidce {Limnoscelis).
Labidosauridoe.

Teeth all sharply conical; enlarged incisors in the premaxillary (sharply inclined backward in
Labidosaurns); anterior cheek-teeth somewhat larger than the posterior; incisor-teeth of the
lower jaw larger than the posterior ones, but smaller than those of the premaxillary. Carnivo-
rous; raptorial.
CaptorhinidEB.

Incisor-teeth of the upper jaws elongate, conical. Cheek-teeth short, conical, and strong, wearing
to a flat surface; clusters of teeth on the maxillaries and dentaries. The median ones of the
outer row of teeth on the maxillary larger than the others in some species. H:ibits somewhat
similar to those of the Diadectidce, but the prey confined to smaller forms. The enlarged
incisors were probably used as in the Labidosaurida;, but less effectively, in loosening clinging
molluscs or extracting such as were concealed in cracks or burrows. Largely molluscivorous ;
not raptorial.
Diadectida;.

Incisor-teeth chisel-shaped; anterior cheek-teeth conical; no caniniform tooth; median cheek-teeth
widened transversely with more or less well-developed tubercles on the inner and outer ends,
and a median eminence, the apex of which was sharp and elongated transversely to tlie greatest
diameter of the tooth. Surface of the cheek-teeth marked by a sculpture of fine radiating
lines when first erupted, but the surface soon worn to a flat or oblique surface. .Small conical
teetli on the vomer. Molluscivorous; possibly partially herbivorous (durophagous).
Bolosaurida; (Bolosaurus and Desmatodon).

Anterior teeth in Bolosaurus small, conical; cheek-teeth large for the size of the animal, with sharp,
elevated outer or inner cusps which i ise above a flat surface at one side of the base. Cheek-
teeth of Desmatodon, the only part known, between those of Bolosaurus and Diadectes. Habits
indeterminable from the teeth."
Pantylosauria.
Pantylus.

Incisors short and blunt; very slightly larger than the cheek-teeth; cheek-teeth short, blunt cones,
apex with short, sharp point when fresh; strong, blunt crushing-tcctli set in plates on the maxil-
lary and dcntary. Molluscivorous (durophagous, conchifragous).
Gymnarthria.

Gymnarthrus ( Cardioccphalus) .

Teeth llattencd conical; greatest diameter antero-posterior; increasing in size from before back-
ward, the incisors being much smaller than any teeth behind them. No great power of seizing,
but seemingly an ability to chew or lacerate, as the most powerful teeth are near the i^osterior
of the jaw. Carnivorous; not predaceous.
Uncertain in Position.
Casea.

Teeth on the edges of the jaws short, blunt cones, few in number, and decreasing in size from before
backward. Palate covered with short, blunt teeth. Williston says that the teeth show con-
clusively that it was herbivorous, and perhaps fed on soft, succulent meadow vegetation.
This statement is not conclusive. The teeth might have been used for hard animal food.
Herbivorous (?) or carnivorous (?); durophagous.

= Broom (Bull. Am. Mus. Nat. Hist., vol. xxxii, art. xxxii, 1913) has recently reviewed the work of
Case upon Bolosaurus, associating parts of the axial skeleton with the skulls, which Case did not feel justi-
fied in doing, and has described as new a form, Opiiideirus, which he distinguishes by tlie presence of acces-
sory cusps on the side of the large cusp. Williston (,Sc., vol. 38, p. 825, 1913) has referred the bones of the
axial skeleton described bv Broom to Arroscelis.

NORTH AMERICA AND THEIR VERTEBRATE FAUNA. I03

FOOD-SUPPLY.

The food-supply of the actively carnivorous forms is easily recognized.
The large coprolites belonging to the Pelycosaiirs and larger amphibians con-
tain abundant reminders of the fate of numerous fishes and smaller reptiles
and amphibians. The frequency with which armored forms occur is ample
evidence of a persistent and effective campaign for subsistence maintained by
the larger carnivorous forms. Unfortunately we are unable to distinguish
between the coprolites of different genera or species. No single specimen has
been determined as belonging with any particular animal, and so no direct
evidence of the food has been found.

If we turn from direct evidence to indirect and examine the possible
sources of supply, we find that little of the vegetation preserved offers much
in the way of food for the doubtfully herbivorous forms. Ferns, horsetail
rushes, lycopods, cordaites, cycadofilices, sphenophyllales, and conifers — no
one of these could have been very readily masticated by animals with such
teeth as we know. True rodent, or triturating, teeth would have been neces-
sary for such plants as the rushes, or for tearing through the tough outer
bark of the lycopods.

The abundant ferns might have furnished a food-supply if they were
eaten. I find but few records of any living forms which eat fern fronds. The
partridge is said to do so, and domestic animals will eat the dried fronds when
they are taken with the hay, but not in any quantity, and not by choice.
They are not touched by grazing animals. Hugh Miller, in his "Testimony
of the Rocks," says that existing plants similar to the fossil flora (ferns and
their allies) "contribute but little, if at all, to the support of animal Hfe."
"The ferns and their allies remain untouched by grazing animals." The roots
are edible, and are rooted out by pigs and eaten. Certain North American
Indian tribes dug out fern roots and baked them for food. While we can not
argue with any certainty that the reptiles of the Paleozoic or Mesozoic did
not eat such things, it is very probable that the fronds were as resinous or
spicy then as now, and no more acceptable. Diadcdcs and Casea were sup-
plied with strong claws, and the former was certainly a powerful excavator.
It is possible that the roots of ferns may have formed some, even a consider-
able, part of the food-supply.

Very likely there were a considerable number of soft, succulent water-
plants which have left no trace in the coprolites and no records of their exist-
ence in the rocks. Moreover, it is to be remembered that the remains of the
animals in all probability do not occur in their normal habitat. The bones
of such as are found in sandstones and shales or in the soft clays were
undoubtedly swept to that place by streams from another locality where
plants were possibly more abundant. In certain places, as the patches of
light blue clay where the remains of small amphibians, sharks, etc., are gen-
erally abundant, plant remains are also common (see White's localities,
below), indicating that the animals were entombed in or near their natural

I04

THE PERMO-CARBONIFEROUS RED BEDS OF

habitat. It is interesting here to recall to mind the feeding habit of certain
turtles. Anyone who has seen a turtle attempting to devour some vegetable
matter must have noticed how singularly awkward and almost helpless it
seems. The food is chewed in an aimless and ineffective way, repeatedly
dropped from the mouth and recovered, smeared with sand and dirt. In
this way a great quantity of hard material gets into the turtle's mouth adven-
titiously, and undoubtedly produces much wear upon the horny covering of
the jaws. If such habits are attributed to the diadectids and similar forms,
it is easily understood how the original form of the teeth would be quickly
and badly worn, as they commonly are in recovered specimens.

Following are the lists of plants given by White,'' from the beds of Texas
and Oklahoma:

'Preliminary List of Fossils from the Main Plant Bed (M) (in the breaks of the Little Wichita, 4} miles south-
east of Fulda) and "Castle Hollow" (H) near Fulda, Texas.

Ta-niopteris multinervis, H, M. Walchia schneidcri? H.

Dij)lothcina sp. ? M.
Pecopteris arborescens, H.
Pecopteris hemitelioides, H, M.
Pecopteris densifolia 7 H.
Pecopteris tenuincrvis, M.
Pecopteris grandifolia, M, H?
Pecopteris sp., M.
Aphlebia sp., H.
Odontopteris neuropteroides, M.
Odaniopteris fischerei 7 M.
Gigantoptcris americana, M, H.
Neuropleris cf. lindahli, H.
Neuropleris cordata ? M.

Taniopleris abnormis, M.
Tcenioptcris coriacea? M.
Ttrniopteris n. sp., M.
Annular ia spicala, H.
Annularia? maxima, M.
Sphenophyllum obovatum, IM.
Sphcnophyllum ? sp., H.
Sigillaria sp., JM.
Sigillarioslrobus hastalus, H.
Cordaites cf. principalis, M.
Poacordaites cf. tenuifoliiis, M.
Walchia piniformis, IvI.

Comphostrobus bifidus, H.
Gomphostrobus ? sp., M.
Aspidiopsis sp., M.
Araucarites, n. sp., M, H.
Carpolithcs sp., H.
Insect wings, M.
Aulhracosia, M.
Esther ia, M, H.
Ostracods, M, H.
Fish scales, M, H.

Provisional List of Fossil Plants from Perry (P) and Eddy (E), Oklahoma.

Diplothema pachyderma, E.
Pecopteris cyathea, P.
Pecopteris geinitzi, P.
Callipteris sp., E.
Gigantopteris americana, E,
Odontopteris cf. permiensis,
Neuropleris sp., E.

P.
E.

Ticniopteris multinervis, P, E
Taniopleris abnormis, P.
Tauiopteris sp., E.
Dolerophylium? sp., E.
Equisetites sp., E.
Annularia stellata, P.
Sphenophyllum obovatum, E.

Sphenophyllum cf. lalifolium, P.
Sphenophyllum stoukenbergi ? P.
Sigillaria sp? P, E.
Walchia imbricata? P.
Walchia cf. gracilis, E.
Araucarites sp., P, E.
Carpolithes, E.

'List of Species Provisionally Identified from the Permian of Kansas: (R) Wreford limestone, west of Reece;
(W) shales near the Winfield formation, northeast of Washington; (B) Wellington formation south of
Banner; (C) Wellington formation south of Carlton; (S) Wellington formation east of Salina.

Schizopteris cf . trichomanoides,W .
Pecopteris unita, W.
Pecopteris pinnalijida, W.
Pecopteris cf. geinitzi, W.
Pecopteris hemiteloides, W.
Pecopteris bucklandi? W.
Pecopteris polyniorpha, W.
Scolccopteris elegans, C.
Ctadophlebis cf. tenuis, C.
Callipteris conferta, W, C.
Callipteris subauriculata, S, C, B.
Callipteris cf. curretiensis, C.
Callipteris cf. juticri, R.
Callipteris cf. goeppcrli, R.
Callipteris oxydata, S.
Callipteris whitci, B.
Callipteris lyratifolia ? S.

Callipteris cf. scheibei, B.
Odontopteris brardii, W.
Odontopteris minor, W.
Glenopteris splendens, B, C.
Clenopteris lineata, B.
Glenopteris sterlingi, B.
Glenopteris lobata, C.
Neuropleris auricidara ? W.
Neuropleris odontopteroides, W.
Neuropleris scheuchzeri, W. (var.)
Neuropleris pcrmiana, W.
Tcenioptcris multinervis, W.
Taniopleris coriacea, B, C.
Tcenioptcris coriacea, var. linearis,

B, C.
Sphenophyllum obovatum, C, B.
Sphenophyllum ci.stoukenbcrgi, W.

Sphenophyllum cf. thonii, W.
Sigillariostrobus hastatus, B.
Noeggerathia ? n. sp., B.
Cycadospadix? sp., C.
Cordaites principalis, R.
Poacordaites linearis ? C.
Walchia piniformis, R.
Walchia ci. filiciformis, R.
Walchia sp., C.
Voltzia sp., C.
Ullmania? sp., C.
Schiitzia ? cf. anomala, R.
Araucarites sp., C.
Rhabdocarpis, n. sp., R.
Carpolithes sp., S, B.

There is little in this list that appears attractive as a vegetable food-supply.

If we search for a possible supply of animal food other than the vertebrate

fauna itself, we are confronted by a rather complex problem. The beds in

" White, Proc. U. S. Nat. Mus., vol. 41, pp. 493-516, 1912.

NORTH AMERICA AND THEIR VERTEBRATE FAUNA. I05

which bones occur afford traces of very Httle that could have kept the animal
alive — tracks of worms, casts, borings, etc., a few crustaceans, like Estheria,
and cockroaches (Etoblattinna) — surely a very meager list. But, again, we
must recall that the animals are rarely embedded in their natural habitat.
This point is abundantly supported by the almost complete absence of any
tracks or foot -prints where the animals occur, and where abundant opportu-
nity was offered for the preservation of such impressions. The author has
searched diligently in the shales and mud stones of the Texas beds for many
days, and has found but a single foot-print of a vertebrate. Williston*
described some small foot-prints from a red shale near Abilene, in Taylor
County, Texas, which show 4 toes on the front foot and 5 behind. He
regards this as evidence that the animals were amphibians. The horizon is
regarded as probably Triassic by Dr. Williston, because it lies closely below
the Cretaceous. With this idea the author is not in accord. The beds from
which the tracks were found lie in the direct line of the southern extension
of the Clear Fork beds, and were so marked by Cummins. The Triassic does
not occur anywhere near so far east in this part of Texas.

If, recognizing that the remains are not in their natural habitat, we turn
to more likely places of abode, probably at no great distance from the places
of interment of the bodies, the matter takes on a different aspect. In many
places in Texas the courses of old streams may be detected in the beds (plate
5, and plate 8, fig. i), and if we follow one of these in imagination a little
way back from the flat, swamp, playa, or lagoon into which it flowed, the
possibilities of invertebrate life are found to be much greater. From the Car-
boniferous rocks of Pennsylvania abundant remains of lowly insects, worms,
arachnids, crustaceans, decapods, and air-breathing gastropods have been
collected ; all exactly such forms of food as would be welcome to insectivorous
animals, or forms with the blunt crushing-teeth. Abundant occurrences of
cockroaches are reported by Sellards'-' from Pennsylvanian and Permian beds
in Kansas, and by Scudder," from West Virginia.

The Clear Fork beds were never far from the ocean, nor free from the
danger of frequent and local incursions. Shells of Myalina occur in very thin
beds of limestone, 2 to 3 inches thick, in restricted areas, or even in beds of
clay, in close association with beds bearing vertebrates.

In local areas in the more persistent beds of limestones occur some other
marine invertebrates which would have afforded abundant food for such
durophagous and conchifragous animals as may have frequented the shores
or even made excursions into the sea- waters, as do Coiiolophus and Sphenodon
to-day. It was in such conditions that the strong, chisel-like incisor-teeth
of Diadcctcs, or the strong, backwardly inclined incisors of Labidosaunis or
Captorhiiius, would be useful in tearing limpet-like forms from the rocks or

» Williston, Biol. Bull., vol. XV, No. g, 1908, p. 238.

'' SoUards, Kansas University Geological Survey, vol. ix, p. 501

" Scudder, Bull. U. S. Geological Survey No. 124.

io6

THE PERMO-CARBONIFEROUS RED BEDS OF

dragging them from cavities, as suggested by Williston. The powerful
crushing-teeth of Diadedcs and Pautylus would have made nothing of the
shells of the nautiloids and other molluscs.

Dr. White =" has given the following list of invertebrates from the Clear
Fork limestone:

Table 2. — List of Invertebralc Speiics from the Texan Permian.

Goniatitcs baylorensis, n. s.

Waagenoccras cumminsi White

Medlicottia copei W

Popanoceras walcotti W

Orthoceras rushensis McChesney?. . .
Nautilus winslowi Meek & Worthen .
N. occidentalis Swallow

3-
4-
5-
6.

8. N. ■

9-
10.
II.
12.
13-
14-
15-
16.

17-
18.
19.
20.

N. ?

N. (Endolobus) ?

Naticopsis remex W

N. shumardi McChesney?

Euomphalus subquadratus Meek & Worthen .

Camp
Creek.

Godwin
Creek.

X
X

Military
Crossing.

X
X
X
X
X
X
X
X

X
X

E. ■

Murchisonia

Patella '

Bellerophon crassus Meek & Worthen.
B. montfortianus Norwood & Patten. .

B. ?

Scdgwickia topekaensis Shumard sp . . .

22. Pleurophorus -

23. Clidophorus occidentalis Geinitz. . . .

24. Yoldia? subscitula Meek & Hayden.

25. Myalina pcrmiana Swallow

26. M. aviculoides Meek & Hayden

27. M. perattenuata Meek & Hayden. . .

28. Gervillia longa Geinitz. . . . .^

29. Aviculopeeten occidentalis Shumard .

30. Syringopora ?

31. Spirorbis ■
3.

Cythere nebrascensis Geinitz.

X
X
X
X

X
X
X
X
X
X
X
X

X
X
X

X
X

SUMMARY.

Species.

MoUusca Cephalopoda 11

Gasteropoda 9

Conchifera 9

Articulata Vermes i

Crustacea i

Radiata Polypi i

Total 32

TERRESTRIAL AND AQUATIC ADAPTATIONS.

As has been remarked above, the Permo-Carboniferous fauna, with the
possible exception of Cricotus and Chcnoprosopus, contain no amphibians or
reptiles which have advanced adaptations to an active aquatic life; there
are no other forms which approach the proportions and form of the body,
limbs, or skull found in forms which spend the major portion of their time
in the water seeking a swiftly moving prey. Undoubtedly many of the
amphibians and reptiles were accustomed to remain in or near the water,
lurking in pools or swamps. The position of the eyes and nostrils, near the

" I. C. White, Bull. U. S. Geological Survey No. 77, p. 16, 1891.

NORTH AMERICA AND THEIR VERTEBRATE FAUNA. I07

upper portion of the head, show that such forms as Rryops, Acheloina, Trenia-
tops, Trimerorhachis, etc., commonly lay nearly submerged in the water, as
do the alligator and the crocodile, while in wait for their prey, but there is
no suggestion in the skeleton of these creatures that they were powerful or
even active swimmers. The short and stubby feet, the broad limbs, the short
tails and plump bodies are those of sluggish creatures. Adaptation to an
active aquatic life is shown in the Amphibia by an elongation of the tarsals,
carpals, and to some extent of the phalanges.

Cricotus was undoubtedly the most powerful swimmer yet discovered in
the fauna. The elongated body, with its long and slender tail; the strong
chevron bones and long, spinous process of the posterior caudals; the elon-
gated form of the skull; all these belong to an active, swift-swimming,
predaceous animal.

The DissorJwpJiida and Aspidosanridcc form a group of amphibians which
were probably far more terrestrial in habits than those mentioned above.
The eyes were larger and more lateral in position. There is a large otic open-
ing, probably covered in life by a tympanic membrane. The limbs are heavier
and the feet shorter. The development of a dorsal armor would increase their
weight, and though this would not compel a terrestrial life, as is amply shown
by the presence of armor in Telcosaurus and the marine turtles, it is connected
with other structures, already mentioned, which suggest habits similar to
those of the land salamanders.

Among the reptiles the adaptations are more varied than among the
amphibians, but not more susceptible of clear interpretation. In the Polio-
sauridce (Poliosaurus, Theroplenra, Ophiacodon, Varanosaurus, Varanoops,
and Pcecilospondylus) the body was elongate, with a moderately long tail;
the skulls somewhat lengthened, with lateral orbits, but in none do the feet
show aquatic adaptations, nor is there any lengthening of the chevron bones
or the spines of the caudal vertebrte which would indicate a swimming tail.
The bones of the feet, carpus, and tarsus, in the animals in which they are
known, are all well formed, with sharp articular siu-faces showing a strength
only to be expected in a terrestrial or scmiterrestrial animal, in which the
body was more or less habitually raised from the ground and supported upon
the limbs in running or walking. In only one genus, Varanosaurus, is the
complete foot known ; in this the strong phalanges terminated in well-developed
claws. In the other genera the feet are only partly known, but in the beds
where they occur, and in associations with the skeletons, are found an abun-
dance of small, sharp, well-formed claws, which must have belonged to them;
such are the claws of terrestrial animals. The members of this family prob-
ably dwelt upon the banks of streams and other bodies of water, not uncom-
monly taking to the water in pursuit of prey or for protection.

In the family Clepsydra pidce {Sphenacodontidce), Clepsydra ps and Dinic-
trodaii were relatively short-bodied, with tails of moderate length, and strong,
fairly long limbs, with well-knit carpus and tarsus. The digits carried strong.

loS THE rERMO-CARBONIFEROUS RED BEDS OF

hooked claws, which in Dimetrodon became talon-hkc in size and form. The
elongate dorsal spines are now known to be exaggerated strvictures, and have
no great significance as adaptations. The animals were evidently highly pre-
daceous, able to rise from their normally prone position and develop con-
siderable speed for a short time, as they dashed upon their prey or attempted
to escape from some aggressive individual of their own kind. Dimetrodon
was evidently a ptirely terrestrial type, but the poorer articulations of the
limb bones of Clepsydrops, with its longer tail, have led to the contention that
it was more aquatic. However, these are not determinate characters.

Arcocdis is characterized by the extreme length and slenderness of the
limb bones, the length of the feet, and the slender cervical vertebrae. These
are features which are always associated with the power of swift motion and
agility in leaping and climbing. Areoscelis undoubtedly equaled in speed and
agility almost any living form of similar kind. It was an arboreal, active
creature of great lightness and speed.

The group Cotylosauriu is characterized as a whole Vjy the extreme short-
ness of the neck, the generally heavy and short body, the firm union of the
dorsal vertebrae, the powerful shoulder girdle, and the short and heavy limbs
and feet. In life the animals were heavy-bodied, large-headed, short-tailed
creatures, moving their bulky limbs in a slow, turtle-like manner, and
depending for protection upon an incipient armor or their tough skin. The
group contains many diverse forms, ranging from the molluscivorous Dia-
dcctes to the predaceous Limnoscelis.

Diadectes. — The broad and powerful humeri of this form, with strong
processes for muscular attachment, suggest a fossorial animal. This idea is
supported by the shortness and strength of the lower limb bones and the
shape of the broad, powerful feet, with short phalanges and nail-like claws.
The broad, depressed body, the heavy shoulder girdle, the large orbits, and
the enormous pineal foramen are all characters which would go well with
fossorial habits. Williston has drawn attention to the fact, however, that
the fore-limbs in Diadectes, Diasparactas, etc., were too short to reach in
front of the nose to an efficient extent, and pertinently queries how such an
animal could dig a hole, as does a badger or a mole. It is not impossible,
however, to conceive that these animals excavated shallow burrows, and it
is altogether probable that the powerful limbs and feet were used in upturning
the earth, tearing apart vegetation, or displacing rocks in search of their food.
Abel has drawn attention to the similarity in the form of the humerus in
many swimming and fossorial forms, but there seems little likelihood that
Diadectes was aquatic in habit.

The large eyes, and the apparently fully functional pineal eye, may be
indications of a crepuscular habit. The incipient armor of plates over the
anterior thoracic ribs, and the considerable probability that there was a
median row of dermal ossicles, show that the animal was subject to attack
from some predaceous creatures, probably the large Diinetrodons.

NORTH AMERICA AND THEIR VERTEBRATE FAUNA. I09

Limnoscelis. — While a true Cotylosaur, and similar to Diadectes in many
points of its structure, Limnoscelis was probably much more aquatic in habit.
The weak tarsus and carpus, largely cartilaginous, covdd not have supported
the body of the animal in the posture of a terrestrial creature. The flatter
head, with the orbits nearer to the upper surface, and the longer and more
powerful tail, are all aqttatic characters.

It would seem that we have in these two animals, very similar in a general
way, adaptations, on the one hand, to terrestrial life, the animal feeding per-
haps on littoral molluscs, and, on the other hand, to an aquatic life, the animal
seeking its active prey in the water, and spending much of its time there.

The families LabidosauridcB and Captorhiuidcc contain the smaller Cotylo-
saiirus, which unite the general characters of the order with those of a greater
agility and a more active life. The firm carpus and tarsus of the Labido-
sauridce, a terrestrial character, is combined with a broad, flat head, such as
is usually associated with aquatic forms. It is probable that the animal lived
near the shore, almost equally at home on the land or in the water. The
captorhinids were probably of similar habits, but, as mentioned in the dis-
cussion of the teeth, were fitted for a diet of hard-shelled creatvires.

Table showing Terrestrial and Aquatic Adaptations and Food Habits.
Amphibia:

1. Aquatic, powerfiil swimmers, active, raptorial:

Cricotus, Chenoprosoptis .

2. Aquatic, perhaps bun-owing in the mud:

Lysorophus, Gymnarthrus, CardioccpJialus (?).

3. Semiaquatic; prol;)ably fair swmxiners, slow moving, raptorial, lurking for prey:

Eryops, Trimerorhachis, Trematops, Achelotna, Zatrachys, Parioxys (?), Aniso-
dexis (?), Tersomius (?).

4. More largely terrestrial, slow moving:

Cacops, Aspidephorous, Dissorhophiis, Alegcinosaiirus.
Reptilia:

1. Semiaquatic, swift moving, raptorial:

Poliosattrus, Varanosaunis, Varanoops, Theropleura, Poecilospondyliis, Ophiacodon.

2. Semiaquatic, slow moving, lurking for prey, carnivorous:

Limnoscelis .

3. Terrestrial, active, raptorial:

Clepsydrops, Dimetrodon, Bathygnathus, Sphenacodon.

4. Terrestrial, slow moving, carnivorous or insectivorous:

Seymouria, Labidosaunis (Littoral).
5- Terrestrial, slow moving, molluscivorous, perhaps partly herbivorous:

Diadectes, Chilonyx, Bolbodon, Bolosauriis (?), Captorhiniis, Dcsmatodon, Dia-
sparactus, Pantylus.

6. Terrestrial or arboreal, very active, insectivorous:

Areoscelis.

7. Terrestrial, active, at least partly molluscivorous:

Edaphosaitrtis.

8. Terrestrial, active, phytophagous (;?(fe Williston) , molluscivorous:

Casea.

THE ASSUMPTION OF ARMOR AND ITS MEANING.

When, in the development of a fauna, a stage is reached where certain
forms begin to assume armor, it is evident that the individuals of that fauna
have reached a very perfect adjustment in their sttrrotmdings. Certain

no THE PERMO-CARBONIFEROUS RED BEDS OF

predatory forms have fixed upon certain harmless forms as their most desir-
able victims, and the harmless forms must seek safety in flight, concealment,
or a defensive armor. Between the forms which seek to protect themselves
by an armor and the predatory forms an active competition generally develops,
the armor growing heavier and more complex, and the weapons of the attack-
ing forms becoming stronger and more efficient. More than once in the
history of the earth such a competition has continued to the complete extinc-
tion of both sides, because the armor became an impossible burden, and the
weapons of attack became so specialized that the food-supply was greatly
restricted.

In the Permo-Carbonifcrous vertebrate fauna of North America this con-
test had reached only into its early stages. Certain amphibians, and at least
one reptile, had developed more or less perfect protecting-plates on the back
and sides. In DissorJiopIius, Cacops, and Alegciiiosaunis the distal ends of the
neural spines are more or less expanded into overarching plates, and a set of
secondary plates lies above and alternates with the expansions of the neural
spines. In Aspidosaurns the protection was confined to the expansion of the
neural spines. In BroUicUiis there are dorsal shields not attached to the
neural spines which are not expanded distally. Dissorophiis was perhaps the
best protected of this group, for the plates descended far down over the sides
in a manner which led Cope to refer to it as a "batrachian armadillo." In
the other genera mentioned the protecting plates are confined to the midline
of the back, and in Cacops to the anterior portion only.

The armor of Diadecles, so far as known, is confined to three plates which
overlie the sixth, seventh, and eighth ribs beneath the scapula. The charac-
ter of the distal ends of the neural spines and the outer surface of the ilium
has led to repeated suggestions that there was a series of median dorsal
dermal elements, as in Pareiasaurus, and perhaps a plate, or plates, over the
pelvic region, but there has been no confirmation of these ideas.

Newman "* has recently drawn attention to the fact that in the Texas
armadillo the armor is not efficient in repelling the attack of dogs used in
hunting it, for the dogs frequently bite through the bony dorsal plates. He
suggests that the armor may be of greater use to the animal as a protection
against the thick brush or thorns or even the jagged sides of narrow crevices
in the rocks into which the animal crowds for safety when it is pursued. The
fact that the armor is much worn in old age is cited in support of this view.
If this idea is correct, it would afford some support to the suggestion of the
author that the Dissorhophidcr and Aspidosauridcc were largely terrestrial in
habit.

Aside from the abdominal ribs which occur in many of the smaller forms,
and which can not be reckoned as defensive armor, the only evidence of
dermal scutes or scales in any member of the fauna above the fishes is found
is Pantylas brcvlspinatus Williston, and certain loose scutes not yet referred

» Newman, American Naturalist, vol. 47, p. 516, 1913.

NORTH AMERICA AND THEIR VERTEBRATE FAUNA. Ill

to any particular form. The lack of a complete, or even fairly complete,
armor indicates that while the predatory and harmless animals were becom-
ing well adjusted to each other in the relation of eater and eaten, the condi-
tion had not yet developed to the stage it reached among the Devonian fishes,
the Mesozoic Dinosaurs, or the later Tertiary mammals.

I have not considered in this discussion that the spines of Dimetrodon or
Edaphosaiiriis were protective in character. That they may have had some
such function in their incipiency, and may have developed from originally
vtseful structures, is possible, but all the attempts, notably those of Jaekel
and Abel, to demonstrate such a protective function seem to me to be based
on wrong assumptions. Such spinous or tuberculated conditions of the skull
as are shown in Zatrachys and Chilonyx may be regarded in the light of protec-
tive defenses, but the forms are too little known to warrant any extended
speculation. They are discussed below among the over-specialized forms.

OVER-SPECIALIZED FORMS.

One feature of the Permo-Carboniferous vertebrate fauna which has,
from its striking character, attracted much attention is the presence of
several forms which have developed, to a remarkable degree, spines, horns,
excrescences, etc. The number and importance of these forms have been
exaggerated, because of their peculiarity, but a careful survey of the fauna,
especially when an attempt at restoration is made, reduces this feature to a
position of much smaller importance than was originally supposed. The vari-
ous structures are, however, of sufhcient importance to warrant a discussion
of their possible origin and effect.

Dimetrodon, Clepsydrops, Edaphosaiiriis, Platyhistrix, Diplocaiiliis, and to
a less degree Zatrachys are the most striking forms. The great horns on the
posterior portion of the skull of Diplocaiiliis and the spinous excrescences on
the skull of Zatrachys are different in form but similar in origin and effect to
the elongation of the spines in the other mentioned genera. All are instances
of the development beyond the point of usefvilness of a structure which may
(must?) have been originally of some value to the animal.

The conceivable causes for the development of such extravagant and
apparently useless structures are:

(i) The overcrowding of a limited area, resulting in a severe struggle for ex-
istence.

(2) A wealth of possible environments, leading to the practical isolation of

forms that would otherwise be eliminated.

(3) Eminently favorable conditions permitting the growth of structures far

beyond an originally useful condition.

(4) The disturbance of a phylum, due to approaching extinction.

(i) The first suggestion seems to the author extremely unlikely to have
been the cause of the structures here considered. The struggle for existence
has many times resulted in the development of very peculiar adaptations.

112 THE PERMO-CARBONIFEROUS RED BEDS OF

but where such a thing has happened the structures have the utmost utiH-
tarian value. A useless or only moderately useful structure would be one
of the quickest causes of extinction under such conditions. The author has
for many years sought diligently for an explanation from a utilitarian stand-
point for the spines of Dimetrodon, Clepsydrops, and Edaphosaiiriis, but he
has utterly failed either to imagine any vise or to gain any suggestion from
others that wovild support such an explanation.

Abel, in his Paleobiologie (p. 430), cites a curious habit in the fishes Histio-
phorous gladius Brouss and Plagyodus ferox Lowe, which is substantiated by
several observers. Both have enormously enlarged dorsal fins, extending
nearly the whole length of the back and reaching a great height. They are
both accustomed to swim near the surface, or to bask with the fins exposed,
and to drift before the wind. Although the fins are totally different in struc-
ture from those of Dimetrodon and Edaphosaitriis, there is a decided similarity
in the external form, and here is a reminder of the original suggestion made
by Cope that both these animals were aquatic. In the opinion of the author,
it has been demonstrated that both Dimetrodon and Edaphosaiirus were ter-
restrial, but he is so far from realizing any use for the dorsal fins of these
reptiles that he can not refrain from mentioning the only case which has come
to his notice where similar structures have an observed use.

Dr. Alexander Ruthven has described to the author his observations on a
large specimen of Basilisciis, noted upon the banks of the Magdalena River,
in the United States of Colombia. This individual ran out upon a rock in
the river in pursuit of an insect and there encountered a strong breeze blow-
ing upon the side of the dorsal fin. Under the pressure of the wind the animal
was thrown well over to one side and seemed to have considerable difficulty
in maintaining its position. Such an effect would have been decidedly in-
creased upon animals with a fin proportionately much greater. This is but
another bit of evidence that the dorsal fins of Dimetrodon and Clepsydrops
were disadvantageous structures.

(2) Environment, as the author has tried to show in another paper," is a
most complex conception, and can only be considered as the sum of all the
contacts of any organism with the world outside of itself, both organic and
inorganic. Isolation, as here used, conveys the idea of the freedom of the
animal from any repressive contacts. An organism might attain such a con-
dition in many conceivable ways, even though it were living in the midst of an
abundant life. If once such a condition were attained, structures which would
ordinarily be removed by selection in the struggle for existence would possibly
attain an unusual development and be eliminated only because of their effect
upon the animal which supported them, or cause the extinction of the animal.

(3) This suggestion is a special case of the former. In the previous sug-
gestion we imagined the animal to be largely freed from any control of its

» Case, Oecological factors of evolution, Bull. Wis. Soc. Nat. Hist., vol. 3, p. 169, 1905.

NORTH AMERICA AND THEIR VERTEBRATE FAUNA. II3

development by the attainment of a particular form of isolation which
relieved it from the necessity of struggle. In this case we suppose the animal
to have developed certain characters which enabled it to triumph easily over
any unfavorable influences (contacts).

As I have reviewed the fauna time after time I have failed to discover
any animal which could in any way compare with Dlmetrodon in agility and
strength, or in its adaptation to raptorial habits. The genus seems to be a
splendid example of the development of a single group to an ascendency over
all its contemporaries. The only active competition which could have oc-
curred would have been between animals of the same genus, since the other
members of the fauna were either harmless in habit or far too small to have
been effective enemies. There was an abundance of food, easily obtained,
no enemies of equal power, and an apparently suitable inorganic environ-
ment, svirface, climate, etc. In other words, the animal was, so far as we can
evaluate the factors, very perfectly adapted to its environment. (Of course,
there may have been antagonistic elements of which we have no knowledge.)
It had reached what Gratcap has called the "zoic maximum."

I may here quote Beecher's words " on the effect produced upon a group
by a very complete adaptation to its surroundings.

' ' The prolonged development or existence of a stock under favorable conditions
for multiplication may he considered as one of the primary influences favoring the
production of spines. This implies abundance of nutrition and comparatively few
enemies outside of other individuals of the same or closely related species. Under a
proper amount of increased nutrition, the vitality and reproductiveness of a stock
are raised, and, other things being favorable, it is found that the stock will give
expression to what has already been described as free variation. Hypertrophy is
also very apt to be one result of abundant nutrition, so that structures of little or
no use may be developed, and some of them comprise certain features which are
often called ornamental.

"bi the excessive multiplication of individuals, it is evident that there must be
a great number of natural variations, and that some of these will affect the pairing
of the sexes in such a manner as to accentuate and delimit certain variations.
Eventually, there also comes a struggle for existence in which favorable modifica-
tions have a decided advantage. In this way it is believed that the great amount of
differentiation found in some isolated stocks has been brought about. Primarily,
then, a favorable condition for nutrition is assumed, which is followed by excessive
numerical multiplication, while the natural variations are augmented and governed
by the action of reproductive divergence for which such conditions are favorable.
Secondarily, these variations are subjected to the influences of cannibalistic selection,
defense, offense, sexual selection, and mimicry.

' ' In illustration of the amount of differentiation attained by a single stock under
favorable conditions, the Amphipod Crustaceans, Gammarus and Allorchestes, found
in Lakes Baikal and Titicaca, respectively, may again be noticed.

"In respect to the number of species, Gammarus is very sparsely distributed
over the world, though in Lake Baikal alone 117 species have been described by

• Beecher, Amer. Jour. Sci., vol. vii, 1898, pp. 266-268.

114 THE PERMO-CARBONIFEROUS RED BEDS OF

Dybowsky. In contrast to this, it may be mentioned that but 4 fresh-water species
have been discovered in the whole of Norway. In Lake Baikal, all the depths ex-
plored (to 1,373 meters) have furnished species. Those living near the surface are
vividly colored, yet apparently make no attempts at concealment. Many of the
species are also highly spinous, though not sufficiently armed to be protected from
the fish. As these Crustaceans are voracious creatures, the spinous character has
probably been favored by the agency of cannibalistic selection. The lake has a
number of species of fish for which the Gammarida; furnish excellent food, but the
presence of a species of seal, prcdaceous fish, as well as the native fisherman, keeps
the fish below the danger point, thus allowing the Gammaridfe to become very
abundant.

"Similarly, in Lake Titicaca there is a wonderful specific development of a
kindred Crustacean, Allorchcstcs. One of the most spinous species (armaiiis) is
also the commonest, and, according to Faxon, occurs in countless numbers.

"Packard shows that among certain moths, the caterpillars, as soon as they
aquired arboreal habits, met with favorable conditions in respect to food, tempera-
ture, etc., and that as spines and tubercles arose by normal variation, such features
being found useful for protection, were therefore preserved and augmented.

" The differentiation of Achatinella has already been discussed as affording a
striking instance of free variation among the Mollusca. The evolution of the
Tertiary species of Planorbis at Steinheim, as described by Hyatt, furnishes another
example, though in neither case has the differentiation of structures proceeded far
enough to result in spines. The costate form {Planorbis costaius) was tending
toward that end, but did not attain it.

"The series of Slavonian Paludina, in the Lower Pliocene, as elucidated by
Neumayr and Paul, show a somewhat further advancement. The species in the
lowest beds (typus Pahidiiia ucmnayri) are smooth and unomamented. Higher in
the strata they are angular and carinated, and at the top of the series the shells are
carinated, nodose, and subspinose (typus Paludina hocrncsi). The living American
genus Tnlotoina is closely related to the most differentiated species (P. hocrncsi),
and its approach to spinose features is more pronounced.

"Under the phylogeny of spinose forms (pp. iS and 19 of Beecher's paper) an out-
line of the life history of the brachiopod Airypa reticularis and derived species was
presented. This being one of the commonest types of brachiopods in the Silurian
and Devonian, often forming beds of considerable extent, it seems quite likely that
its prolonged development under favorable conditions for multiplication must have
had an effect on the amount and kind of variation.

"It has been noticed by Brady and others that in the Foraminifera, Glohigerina
bulloides, Orbidina universa, etc., the pelagic forms comprise two varieties which are
generally distinct, a spinous form, and another with small, minutely granular shells.
The bottom specimens of the same species are also commonly without spines, and
often smaller. The interpretation seems to be that the large specimens indicate an
abundance of nutrition, which also produced hypertrophy of the normal granules
into spines. Some bottom specimens are large, but they are usually abnormal and
of a monstrous or pathologic nature.

"From the foregoing examples, the conclusion to be drawn is that, with full
nutrition, there comes a nimierical maximum, and naturally with this a correspond-
ing number of normal variations. Some of these modifications, as spines, have
arisen by hypertrophy. After having thus originated by growth force, they may
or may not be of use for offense, defense, or concealment, or in any way give their
possessor a distinct advantage."

NORTH AMERICA AND THEIR VERTEBRATE FAUNA. II5

Though these remarks apply to the Amphipods Gammarus and Allor-
chestes, and other invertebrates, it is apparent that they are just as appHcable
to the vertebrate Dimetrodon and related forms among the Pelycosauria.
Practically withdrawn from any struggle for existence (so far as we can see)
and abundantly nourished, the excess vitality of the animal was used in the
elaboration of structures, possibly useful in their inception, until they became
elements of weakness, and finally an efficient cause for the extinction of
the group. The drain upon the animals' vitality necessary to elaborate such
structures and to maintain them in repair, for they were frequently broken
by accident and in conflict with other animals, could only be supported when
the animal was in the height of its vigor. When for any reason the animals'
powers were lessened, the support of the structure would become a disad-
vantage so great that it would result in the decadence of the individual and
the extinction of the group.

Loomis'^ has argued for a "momentum of variation," or evolution, which
he supports by many cases very similar to that of Dimetrodon. If such a
principle exists, as seems very probable, the tendency to maintain structures
already developed would be an added cause for the extinction of a group when
it had commenced its decadence.

This argument is based on the belief that the spines were useless struc-
tures. Jaekel and Abel have contended that they were of distinct importance
in repelling the attacks of enemies, but, as has been shown, the only enemies
were individuals of the same genus, and a struggle between individuals of a
genus could have no bearing on the development of the genus itself.

A similar argument can not be extended to the genera Edaplwsaurits,
Diplocaulus, or Platyhistrix. They may have developed their peculiar struc-
tures under conditions outlined in the .second suggestion.

The line of reasoning here followed leads inevitably to the question
whether the perfect adaptation of any group to its environment may not be
as great a danger to the group as a severe struggle for existence. In the
struggle the individual suffers, but the group represented by the best indi-
viduals survives. If the group as a whole reaches, or approximates, perfect
adaptation, the momentum of variation, aided by superabundant vitality
due to full nourishment and lack of effective control, would result in the exag-
geration of structures until they became a fatal defect. Perfect adaptation
is a possible cause of extinction.

(4) The last one of the possible causes for the development of seemingly
useless structures is the disturbance of the phylum due to approaching extinc-
tion, as suggested by Beecher.'' When the high-spined forms were supposed
to be the dominant types of the Permo-Carboniferous vertebrate fauna and
their distribution was supposed to be much more limited than it is now known
to be, this idea would have been applied to the whole fauna, but now it can

" Loomis, Amer. Nat., vol. 39, p. 839, 1905.
'' Beecher, Amcr. Jour. Sci., vol. vii, 1898.

Il6 THE PERMO-CARBONIFEROUS RED BEDS OF

be considered only in its application to the few genera, Dimetrodon, Clepsy-
drops, EdapJiosaiinis, and, perhaps, Diplocaulus. They were no more import-
ant in the fauna as a whole than PJirynosoma or Basilisais is in the fauna of
the regions in which they live to-day, or than Stcgosaums or Triceratops were
in their time and region. It is, perhaps, of some value to test Beecher's
theory in these cases.

I quote several paragraphs selected from his valuable paper, to show the
line of his argument, and his conclusions.''

Page I : "The presence of spines in various plants and animals is, at times, ob-
vious to all mankind, and not unnaturally they have come to be regarded as almost
wholly in the light of defensive and offensive weapons. Their origin, too, is com-
monly explained as due to the influence of natural selection, resulting in the greater
protection enjoyed by spiniferous organisms. But when, upon critical examination,
it is seen that some animals are provided with spines which apparently interfere with
the preservation of the individual ; that other animals develop spines which can not
serve any purpose for protection, or otherwise; and that spines themselves are
often degenerate or suppressed organs, then it becomes evident that the spinose
condition may have other interpretations than the single one of protection."

Page 2 : ' 'After studying numerous organisms, the writer is led to believe that
in every case no single reason is sufficient to account for their spinose condition.
The original cause may not be operative through the entire subsequent phylogeny,
so that spines arising from external stimuli, and then serving important defensive
purposes, may at a later period practically lose this function ; or spines may become
more and more developed, simply by increasing diversity of growth forces, or through
the multiplicity of effects. In this way causes may follow, overlap, or even coincide
with each other; but in interpreting special cases, the problems may be quite com-
plicated, and often obscure."

Page 128: "* * * modifications in function and structure are followed by modi-
fications in surface, showing that the more important physiological and structural
variations are the first to be subjected to heredity and natural selection, which tend
to fix or hold them in check. Features of less functional importance, as peripheral
characters, are the last to be controlled, and therefore present the greatest diversity,
while in this diversity spinosity is the limit of progress."

Page 266: "Hypertrophy is also apt to be one residt of abundant nutrition, so
that structures of little or no use may be developed, and some of them comprise
certain features which are often called ornamental."

Page 332 : "The physiological inteq^retation of spinosity is a correlative of the
morphological aspect of the same condition, and, as it was found that spinosity was
a limit to morphological progress or regress, it will now be shown that it also indicates
the paracme or decline of physiological progress. Both inferences are drawn from the
individual or ontogenetic standpoint, as well as from the radical or phylogenetic."

Page 353 : "It has been shown elsewhere in this article that the greatest develop-
ment of spinose organisms occurs just after the culmination of a group, and, as this
period clearly represents the beginning of the decHne of the vitality of the group,
the spines are to be taken as a visible evidence of this decadence. A similar obser-
vation has been made by Packard, who after passing in review the geological develop-
ment of the Trilobites, Brachiopods, Ammonites, states that ' these types, as is well
known, had their period of rise, culmination, and decline, or extinction, and the

" Beecher, Amer. Jour. Sci., vol. vii, 1908.

NORTH AMERICA AND THEIR VERTEBRATE FAUNA. 1 17

more spiny, highly ornamented, abnormal, bizarre forms appeared at or about the
time when the vitality of the type was apparently declining.'

"Furthermore, it is now commonly agreed that all groups have been most
plastic near their point of origin, or, in other words, that during their early history
all the important or major types of structure have been developed. Their subse-
quent history reveals the amount of minor differentiation and specialization they
have undergone during their period. Apparently most of the early impulses of
growth, whether from the environment or from vital forces, resulted in physiological
changes producing fundamental variations in function and structure. The later
influences, of environment and growth force, are expressed in peripheral differentia-
tion, and show that the racial or earlier characters had become fixed, and that the
later or specific features were the chief variables. The stimuli which, during the
early life history of a group, were expended in internal or physiological adjustments
later produced external differentiation, and in this differentiation spinosity is the
limit. The presence of spines, therefore, indicates the fixity of the primary physio-
logical characters, together with the consequent inability of the organism to change
due to its decrease in vitality."

Two things are very noticeable in these quotations, which express the
tenor of the whole article. First, that Beecher believed that spines may be
useless structures, and, second, that he believed that they occur when an
animal has reached its maximum of vitality. I believe that the develop-
ment and extinction of the Dimetrodon-Wke forms is amply explained by
the hypotheses of Beecher and the author set forth above.

In an unsigned review of Dr. Williston's American Permian Vertebrates,
and the monographs by the author on the Cotylosauria and Amphibia of the
Permo-Carboniferous of North America, the Geological Magazine (Nov.-
Dec, 1912, p. 519) says:

"These animals {Cacops, Dimetrodon, and Edaphosaurus), and many others,
seem to exhibit all the features which usually occur in the last individuals of a race ;
they are phylogerontic, and it is improbable that they left any descendants. The
Texan Amphibia and Reptiles are, then, precociously specialized examples of the
earlier stocks which in South Africa slowly developed along many lines and gave
rise to the mammals among other groups. Diplocanlus may be a terminal member
of the line of the Microsauria, represented by Ccratcrpcton and Diccratosaurus,
which occur in Europe and North America."

ORIGIN OF THE FAUNA.
REPTILES.

Williston'' has recently stated his opinion that the old name Theromorpha
(correctly Theromora) should be reestablished to include "all the American
therocrotaphic forms at least," and by implication he includes the South
African Tkerapsida (Am. Perm. Vert., p. 71). Broom'' earlier made similar
suggestions in that he insists on the close genetic relationship of the African
Tkerapsida and the American Pelycosaiu-s, but as I tmderstand him, he does
not suggest their tmion in the group Theromora.

• Williston, Science, vol. 33, p. 632; Am. Perm. Vert., p. 71; Jour. Morph., vol. 23, p. 639 et seq.

^ Broom, Trans. Roy. Soc. S. Af., vol. I, 1910, p. 473; Bull. Amer. Mus. Nat. Hist., 1910, July, p. 197.

Il8 THE PERMO-CARBONIFEROUS RED BEDS OF

Broom says, in the Bulletin of the American Musevim of Natural History
for 1910, page 228:

"Though it is many years since Cope first caHed attention to the resemblance
between some of the American and African types, of later years zoologists have been
more impressed by the difTerences. Like most others, I had regarded the resemblances
as more due to a parallel development than to afhnity, and I was a little surprised to
find that the resemblances were of a more fundamental nature than had been sup-
posed. Not only do certain American tyj^es resemble, somewhat remotely, of course,
African forms, but the whole fauna has got an African look about it that is very
striking. Williston regards the American Permian reptiles as belonging to three
groups: the Pelycosaurs, the Cotylosaurs proper, and the Pariotichus group; and it
certainly is very remarkable that some years ago, writing of the reptiles of South
Africa, I placed them in the groups Procolophonia, ParciasaHria, Thcrocephalia,
Anomodoutia, and Cynodontia. If we unite the alhed mammal-like groups, Thcro-
cephalia and Anomodontia, under the Therapsida, and omit the Triassic Cynodontia,
we get our principal Permian reptiles also in three groups, and, further, the three
groups correspond in many ways to the American. The Pelycosaurs resemble the
Therapsida; the Cotylosaurs the African Pareiasauria, and the Pariotichus group
the Procolophonia. ' '

And further, on pages 230 and 231 :

"From these points of comparison I think one must conclude that the Pelyco-
sauria are allied to the Therapsida. In some respects the former are more specialized,
but in most they are more primitive. The skull, while essentially similar in the two
types, is more primitive in the Pelycosauria than the Thcrocephalia in the retention
of the quadrato-jugal and perhaps of a post-parietal and post-temporal. It is less
primitive in the loss of the transpalatine. The Dinocephalia, alone among the
Therapsida, retain the primitive quadrato-jugal. The Dromasauria alone have the
primitive character of the lachrymal meeting the septo-maxillary, a character also
seen in Edaphosaurus, and the possession of abdominal ribs, also present in some
Pelycosavirs.

"In retaining the typical Diapsidan digital formula the Pelycosauria is more
primitive, but though the Therapsida have acquired the mammalian formula of
2, 3, 3, 3, 3, to suit the placing of the feet under the body, and to bring the toes into
line, we can see from the condition of the metatarsals and metacarpals in the
Dromasauria that this formula has probably only been recently acquired, and that
the feet are not yet completely suited to the new mode of walking.

"The conclusion to which I come is that the Pelycosaurs and Therapsida had
a common ancestor in the Upper Carboniferous times, which was characterized by
having the typical Diapsidan digital formula, abdominal ribs, a single temporal
fossa, a quadrato-jugal bone, and a Rhynchocephalian palate. Such an ancestor
could be so near the ancestral Rhynchocephalia or Diaptosauria that, though it had
only a single temporal fossa corresponding to the lower one in Sphcnodon, it ought
to be regarded as a Diaptosaurian, and though the Pelycosauria are speciaHzed in
a number of respects, I should still keep them in the Diaptosauria.

"The South African Therapsidans have sprung from the same ancestor, but
have developed in a different way. By a change of habit the Hmbs have become
more powerful, and by the adoption of the habit of walking with the body off the
ground the digital formula has been changed from 2, 3, 4, 5, 3 to 2, 3, 3, 3, 3.
The changes in the skull are of less importance, the only marked one being the loss
of the quadrato-jugal. The Dromasauria are perhaps quite as near to the common

NORTH AMERICA AND THEIR VERTEBRATE FAUNA. Iig

ancestor as are the Pelycosaurs, but as they are on the mammaUan hne, I should
keep them in the mammal-like phylum, and regard them as the most primitive
division of the Therapsida."

In a recent paper on the genus Bolosaurus, Broom" reiterates his views
and presents further evidence.

Watson, in a recent paper,*" has expressed his idea of the necessity of
uniting the North American and South African forms. After a detailed
discussion he says:

"The final result is that the presence of the Deinocephalia makes it impos-
sible to exclude the American Lower Permian and Carboniferous Pelycosaurs from
the later South African Therapsids. Such a division could any time have been
drawn only on the more primitive limbs and large quadrate of the early forms;
the fact that in Deinocephalia we have types with a quadrate as large as that of
the Pelycosauria combined with modernised limbs renders the foundation of a
great group division on these characters quite impossible.

" For this great stem of the Reptilia, including all the mammal-like reptiles,
many names are available. I am myself inclined to extend Broom's Therapsida,
a most appropriate name, to the whole of them, but I fully recognize that Coi^e's
earlier names of Theromorpha and Theromora have been used in the same sense ;
these names were never very clearly defined by Cope, and have at one time or
another included nearly all Permian reptiles. If any one should wish to resusci-
tate these names in this connection, I would point out to them that Owen's term
Anomodontia was used by that author in i860 in a wide sense to include the
Dicynodonts and also carnivorous Therapsids from South Africa, and has at least
as good a claim to be used as Cope's later terms."

Broom and, especially, Williston insist upon the hopelessness of any
attempt to present a permanent classificatiori of the early reptiles at the
present time when only a portion of the fauna is known, and that portion,
in the main, forms fragmentary skeletons. It is largely in recognition of
the inadequacy of our information and the failure of many recently pro-
posed classifications by Osborn, Jaekel, and others, as I understand Dr.
Williston, that he proposes a return to what he considers a stable basis, and
proposes to unite the Pelycosauria, Protcrosauria, Caseasauria, Kadaliosau-
rida;, and the Therapsida as suborders under the old order Theromorpha.''

His classification is as follows:

Order Theromorpha :

Suborder Pelycosauiia.

Family Cleps3'dropsidffi (Sphcnacodontida;).

Family Poliosauridae.

Family Edaphosaurida;.
Suborder Proterosauria.

Family Paleohatteridse.
Suborder Caseasauria.

Family Caseidas.
Suborder .

Family Kadaliosaurida; ( Ara^oscelida-) .

"Broom, Bull. Amer. Mus. Nat. Hist., vol. 32, p. 515, 1913.
•"D. M. S. Watson, Proc. Zool. Soc, London, vol. 1914, p. 778.
Williston, Jour. Morphology, vol. 23, p. 649.

I20 THE PERMO-CARBONIFEROUS RED BEDS OF

As he says, the classification does not take into consideration the ten-
dencies of evolution in the group.

"I am aware that this classification is what might be called 'horizontal,' rather
than 'vertical;' but I also insist that horizontal classifications are absolutely im-
perative until such time as we have more than vague surmises and guesses as to
the true lines of phylogeny."

The opposite point of view is adopted by Osborn in his paper on the
"Reptilian Subclasses Diapsida and Synapsida, and the early history of the
Diaptosauria." He says:"

"In my opinion classification should directly follow, formulate and express our
progressing knowledge of phylogeny ; for example, if the Proterosauria prove to be
ancestral to the Dinosauria, as I suspect, then the order Proterosauria should be
transferred to the superorder Dinosauria, as constituting a common stirp, a common
blood relationship, a common tendency to evolution. As soon as a certain evolution-
ary direction is assumed by a certain group of animals toward a higher group,
although the evolution may not have proceeded very far, the lower and the higher
groups should be united in classification, and thus segregated from groups diverging
in other directions."

After all, these two writers are not far apart, for, were Dr. Williston con-
vinced of the correctness of the phylogenies proposed, he would assuredly
follow the plan suggested by Osborn.

The author has discussed the early reptiles in great detail with Dr.
Williston, and is in accord with him in most of his statements and conclu-
sions, but can not entirely agree with him in his proposed classification. He
is inclined to think that Dr. Williston has assumed too conservative a posi-
tion in the matter, and to think that enough of the main phylogenetic lines
are determinable to warrant a more definite statement.

Williston, in his analysis of the Permo-Carboniferous reptiles, gives the
following list of constant characters in the Theromorpha:

One or two temporal vacuities on each side.
Neck of greater length.
Neural arches never stout.

The last character can not be strictly maintained, as Parilos pond y! its
Case has the neirral arches of a portion of the vertebral column quite stout.
This is the only exception to the rule, so far as I know.

The contention of Dr. Williston is that all the other characters, inconstant
ones, are not sufficient to separate the American and the South African forms
ordinally, and they must be combined. But the constant characters are
extremely primitive, exactly such as would be found in a common ancestral
group, and are such as might be retained in many variations in widely
divergent lines.

Although it is frankly admitted by the author that divergence has not
gone far enough in the Permo-Carboniferous reptiles to eliminate all the

' Osborn, Memoir Amer. Mus. Nat. Hist., vol. i, part viii, p. 504, 1903.

NORTH AMERICA AND THEIR VERTEBRATE FAUNA. 121

resemblances between the South African and the American forms, he beUeves
that it is possible to demonstrate a well-established tendency in their evolu-
tion and well-established stages of evolution in different lines of these reptiles,
and he believes that this is the essential point in any true classification, which
must consider the phylogeny of a group.

Broom has shown and insisted upon the important tendency in the evolu-
tion of the South African forms toward the lengthening of the limbs, the
strengthening of the tarsus and carpus, a reduction of the digital formula to
2. 3, 3, 3, 3, the change in the pelvis and scapula, the reduction in the size
of the bones in the articular region of the jaw, and the enlargement of the
squamosal with a coincident reduction of the quadrate. He says: ""

"The Pelycosaurs were slow-moving crawlers with short, lizard-like limbs; the
Therocephalians were active runners, with mammal-like limbs. The structure in
the limb girdles is in harmony with the diflferences in the limbs."

Again:''

' ' If this conclusion be correct, we may regard the American and South African
Permian faunas as derived from a common origin, but having evolved in quite
different directions. The American types undergo many curious specializations.
The African, or more preferably the South Atlantic type, is chiefly remarkable for
the great development of the limbs. The Pareiasaurians, the Dinocephalians, the
Therocephalians and the Anomodonts have all developed powerful limbs, and not
improbably all independent of each other. What may have been the cause we can
not at present tell, but it was a most fortunate thing for the world. It was the
lengthened limb which gave the start to the mammals. When the Therapsida took
to walking with its feet underneath, and the body off the ground, it first became
possible for it to become a warm-blooded animal. ' '

None of these points would Williston dispute. If he were to simply insist
that the South African and the American Permo-Carboniferous reptiles were
a heterogeneous group, with many distinct specializations, but retaining cer-
tain primitive characters upon which the specializations were based, there
could be no contention, but to fail to fully weigh the manifested destiny of
radically different groups seems to the writer too conservative to express the
state of our knowledge. While agreeing with Williston in the futility of
attempting a detailed classification, the author desires to express his opinion
of the situation as follows:

(I) American Permo-Carboniferous Therocrotaphic reptiles (Pelyco-
sauria). With primitive characters allying them to the African Therapsida,
and pointing to a common ancestor, but with all their specializations upon
a reptilian theme, and leading to extinction, or higher reptiles.

(II) South African Permian Therocrotaphic reptiles (Therapsida). With
primitive characters allying them to the American Pelycosaurs, and pointing
to a common ancestor, but with all their specializations upon an advancing
theme, and leading to extinction, or to the Mammalia.

» Broom, Trans. Roy. Soc. S. Af., vol. i, 1910, art. 2.

•• Broom, Bull. Amer. Mus. Nat. Hist., vol. 28, art. 29, p. 234, 1910.

122 THE PERMO-CARBONIFEROUS RED BEDS OF

This goes no further than to state the author's behef that the American
and South African forms had developed sufficiently far to indicate their main
lines of evolution so clearly that we are able to recognize that they belong to
separate phyla. "

As has been repeatedly intimated in this discussion, the group called

Pelycosauria is now recognized as a composite group, and while I am unable

to agree with Dr. Williston that they should be grouped with the South

African forms as Theromora, I do agree with him in his subdivision of the

fauna into distinct groups. If I am mistaken in his views, and he is inclined

to restrict the Theromora to the American forms, as he apparently does in

his Review of the Primitive Reptiles (p. 649), then I think we are together,

accepting the Theromora as a provisional order. My arrangements would

be only slightly different from his:

Order Theromora.

Suborder Pelycosauria.

Family Clepsydro] )idre (vSphenacodon Udiv) .

Family Poliosaurida;.
Suborder Edaphosauria.

Family Edaphosaurida'.
Suborder Protcrosauria.

Family Paleohatterida;.
Suborder Caseasauria.

Family Caseida;.
Suborder Kadaliosauria.

Family Kadaliosauridic.

Family Areoscelid;c.

Edaphosaurus can not justly be retained in the Pelycosauria. The genus
is as distinct from either Clepsydrops or Dimetrodon as is Casea or Areoscclis.
The high spines which gave the original idea of a kinship with Dimetrodon
can only be regarded as a parallel character, found also in PlatyJiistrix. The
bones of the skiill are uncertain. Case and Broom, not being in accord on all
points, and Williston agreeing with neither. But the possible extent of the
lachrymal to the nares (Broom and Williston) ; the possible presence of post-
parietal bones; the totally different dentitions and diet; the different shape
of the axis; the different proportions of the upper and fore arm and leg; the
presence of an ectcpicondylar foramen in the hvimerus; the different shape
of the ilium and femur; the totally different habits of life, are sufficient to
place it in a separate suborder.

The Poliosauridas, generally grouped with the Pelycosauria, are equally
close to the Protcrosauria, as suggested by Williston. The imperfectly
ossified condition of the pectoral and pelvic girdles are explainable upon the
hypothesis of an aquatic adaptation, which is borne out by the presence of
the sclerotic plates (Williston) , and admitted as possible by Osborn because
of the distal expansion of the humerus and the imperfect ossification of the

" Broom's citation of the similarity of the structure of the jaw in Pelycosauria and Dinocephalia (Bull.
Amer. Mus. Nat. Hist., vol. 33, art. 9, 1914, p. 141) is but an instance of a line of a general group which,
departing from, or, better, refusing to follow, the manifest destiny of its relatives, suffered the usual fate,
e.xtinction.

NORTH AMERICA AND THEIR VERTEBRATE FAUNA. 1 23

tarsus and carpus. The possibility that all the specimens described by Cred-
ner are immature, as suggested by Osborn, must not be lost sight of.

We know nothing of the feet of the Poliosaurida?, other than in the genus
Varanosauriis, but these are the feet of a typical land reptile, with well-
ossified interlocking elements in the wrists and ankles. I can not but believe
that the ideas proposed in my first monograph vipon the Pelycosaurs were
correct; that the series represented by Poliosaiirus, Clepsydrops, and Dime-
trodon is a morphological series, representing stages in the development of
the phylum, and if we add to this series, as a beginning member, a Protero-
saurid individual, we would have representatives of the group from its incep-
tion to its extinction.

Not improbably the Caseasauria, Kadaliosauria, and Edaphosauria were
derived from some lower member of this line. This would in no wise exclude
Osbom's hypothesis that the Dinosauria were derived from the Proterosauria.

The origin of the Cotylosauria directly from the Stegocephalia has not
been questioned by those familiar with the group. That no one of the known
forms can be considered as a connecting link is well accepted. Seymouria
and Pantyliis are both very close to the Amphibia in the characters of the
skull, but neither of these is conceivably in the direct line. It is practically
certain that we must turn to one of the smaller, less well-known forms,
Pariotichiis, Isodectes, Sanraviis, Eosanravus, Ectocynodon, or some similar
form, for the connecting link. As in every case of a proposed phyletic series,
we can approach more or less closely to a point of union from both sides, but
the known forms are all too highly specialized to occupy the exact position.

The Amphibia are all closely connected with the true Carboniferous
amphibians^so closely that we can only see in them a direct continuation of
the phylum.

CHAPTER VI 11.

DESCRlPnON OF INDIVIDUAL GENERA.
PISCES.

A review of the list of fishes (see table, page 96) shows that by far the
larger number were inhabitants of fresh or brackish waters. Indeed, it is
doubtful whether there were any which were truly marine. Of the sharks
we know little, but it is a well-estabUshed fact that some of the living forms
of this group are inhabitants of fresh waters, and DoUo has asserted that the
form of the caudal fin and the archipterygium form of the lateral fins in
Pleuracanthiis indicate a fresh-water habitat and are benthal in character.''
Plciiracanthus. — Carnivorous, benthal, and fresh-water.'' Size, form, and
proportions unknown.

Diacranodiis, Ctenaauithus, and Anodontacanihus {and possibly Ilyho-
dn^-) _ — These were all carnivorous forms, and probably of the same general
habits as Pleiiracanthus . Known only from spines and fragments.

Janassa. — This was evidently a mollusc eater, and from its broad and
ray-like form probably kept close to the bottom in shallow water.' Known
only from the teeth in America.

The Dipnoans and Crossopterygian and Actinopterygian ganoids were
all dwellers in fresh and brackish waters. So little is known of these forms
in the Texas fauna that it would be useless to attempt to describe any of
them, but it is important to note that not one is indicative of the presence
of salt water. Their remains always occur in sandstones and clays or shales
associated with amphibian and reptihan bones, and never, so far as I have
observed, with marine invertebrates. This all goes to confirm the supposi-
tion that the Texas deposits, other than some of the limestones, were laid
down in pools upon the surface of a delta or fiat beyond the reach of marine
waters.

AMPHIBIA.

The following descriptions and restorations include only the better-known

genera :

Diplocatdus (fig. 13).— A great deal of work has been done upon the genus
and descriptions of the skull, vertebral columns, and parts of the limbs have

» Among living fresh-water Selachians are the following: Carcharias gaiigeticus is found high up in the
rivers of India, and also in the Tigris River near Bagdad, 300 miles from the Persian Gulf. The same shark
is found in a lake on Viti Levu (Fiji Islands), which is shut off from the sea by a cataract. Carcharchinus
nicaraguensis is found in Lake Nicaragua and its outlet, the Rio San Juan. This shark is confined, so far
as known, to fresh waters, and is the only strictly fresh-water shark recorded.

t" DoUo, Bull, de la Soc. Beige de Geol. de Pal. et d'Hydrol, Tom. xxi, 1906.

" Jaekel, Geol. Gesell. Zeitsch., 1899; Zittel (Broili), Grundz. d. Paleon., sec. ed., p. 62, figs. 107-109.
124

NORTH AMERICA AND THEIR VERTEBRATE FAUNA.

125

been published. We now know the' skull, practically all of the vertebral
column, the interclavicle, clavicles, coracoid, humerus, femora, and some of
the metapodial bones. For a long time after it was discovered no bones of
the limbs, feet, or pelvic and pectoral girdles were found associated with the
skulls and vertebrae, and the animal was considered to be limbless. Williston
first discovered and described the limbs and the coracoid. The broad skull,
terminating behind in the heavy horns of solid bone, and the large plate-like
clavicles and interclavicle, show that the normal position of the animal was
flat upon the belly. The limbs were short and relatively weak ; the posterior
a little larger than the anterior; the body slender, terminating in a long tail.
It is possible that Diplocauliis may have been able to move with consider-
able rapidity through the water, driven by its strong tail. Broili suggests
that the presence of zygosphene and zygantrum articulations between the
vertebrae indicates some rapidity of motion. The weight of the absurdly
large head at the extremity of the slender body suggests considerable mechan-
ical difficulty in the act of swimming. The head would have constantly

Fig. 13. — Restoration of Diplocaulus magnicornis Cope and Lysorophus tricarinatus Cope.

dragged downward, compelling a sustained effort of considerable power to
maintain a unifomi lateral or upward motion. The broad, flat head might
have acted as a guiding-plane to the animal's motion and, as long as held
horizontal or pointed upward, would maintain the animal's direction, but
the weight would soon drag it down, for there were no muscles or ligaments
adequate to svipport it, as is shown by the lack of an enlarged neural spine
upon the axis. It is to be noted, however, that the articular condyles he
almost equally distant between the two extremities of the skull and the skull
may have been so balanced upon them as to give some freedom of movement.
It is far more probable that Diplocaulus habitually lay upon the bottom
of pools or streams, advancing by a wriggling motion, somewhat in the
fashion of Necturus, aided by the weak feet, or driven by strokes of the power-
ful tail. The location of the eyes and nostrils, entirely upon the upper surface
of the skull, is just such as would be most useful to an animal with such a
habit. Moving sluggishly over the slime of the bottom, it would devour

126 THE PERMO-CARBONIFEROUS RED BEDS OF

such weak-shelled or soft-bodied invertebrates, crustaceans, worms, insect
larvae, etc., as it might discover, and it probably did not refuse carrion, or
even vegetable matter of some kinds.

It has been suggested that the great projecting horns may have sheltered
external gills, but of this we have no knowledge. Perhaps the animal rose
to the surface at long intervals for air, or pushed its nose beyond the edge of
the water along the bank. Mr. Paul Miller has noted the fact that the bones
of Diplocaulus are almost always associated with the teeth of sharks, which
may be taken as confirmatory of the fresh-water habits of ancient sharks,
and perhaps as an indication of a favorite food.

A tracing of a nearly complete specimen furnished the author by Mr.
Doughtett measures approximately 950 mm. This would be a good-sized
individual of Diplocaulus magnicor)iis.

Eryops (plate 20, fig. 2). — The skeleton of the genus, typically represented
by Eryops mcgaccphalus, is as completely known as any form from the Permo-
Carboniferous Red Beds. It was the largest of the amphibians, reaching a
length of 6 feet or more. If, as restored in the American Museum of Natural
History in New York, it had a long tail, the length may have been even
greater. Dr. Matthew assures me that the long tail is warranted by speci-
mens which I did not see when working upon the collections in the American
Museum. Neither Dr. Williston, Mr. Paul Miller, nor myself, all of whom
have collected several times in the Texas beds, has seen any evidences of
such a long tail, and I have collected two specimens in which the nearly perfect
vertebral column indicated that the tail was decidedly short, as I have restored
it. (Carnegie Inst. Wash. Pvib. 145, plate 9.) It is also to be noted that in the
original figure of the vertebral column given by Cope '^ the vertebras, which
he speaks of as having coossificd chevrons and near the extremity of the tail,
are still of good size, indicating that there was a rapid decrease in the size of
the caudal vertebras and a short tail, if his observation of the position of
these vertebras is correct. The bifurcated distal ends of the neural spines of
the anterior caudal vertebras afford some support to the idea of a long tail,
as they would have given attachment to powerful muscles and tendons.

Long-tailed or short-tailed, Eryops was a heavy-bodied Stegocephalian,
with a large head and relatively short limbs. The bones of the limbs show
the attachment of powerful muscles, and the carpal and tarsal bones were
well formed and closely articulated. The clavicles and interclavicles were
relatively small and the pelvis was a solid mass of coossificd elements. The
foot, as indicated by the phalanges, was short and strong. Altogether the
skeleton gives the idea of an animal with considerable ambulatory powers,
able to raise the body well off the ground in progression; a totally different
creature from the weak-limbed Triassic Metopias, with its great pectoral
shield formed of the clavicles and interclavicle, which protected the thorax

° Cope, Proc. Amer. Phil. Soc, vol. xix, pi. in, 1880.

NORTH AMERICA AND THEIR VERTEBRATE FAUNA.

127

as the body was shoved forward on the ground. The thoracic ribs were some-
what expanded, as in several amphibians of the same fauna, probably as a
partial protection against some prowling Dimetrodon, which would have had
Eryops at a decided disadvantage if the encounter took place upon the land.

Undoubtedly Eryops spent much of its time in the water, and found there
its chief food supply. The position of the eyes and nostrils near the top of
the skull shows that it could, and probably did, lie nearly submerged in the
water until the approach of some fish or small amphibian or reptile was
sufficiently close to warrant a sudden rush with its enormous jaws distended,
and by a sudden snap drive home the powerful tusks, from which there was
no escape.

No coprolites have been definitely associated with the skeletons of
Eryops, but large ones occurring in great abundance in the same beds con-
tain remains of fishes and small bones of other vertebrates.

The bones of this animal are among the most common in the Texas and
Oklahoma beds, and have been found in Kansas, Illinois, and Pennsylvania.
Evidently the genus was represented by numerous individuals and was
widely spread over the continent.

Closely related to the Eryops were Parioxys and Anisodexis, known only
from the skulls, but while they were probably of similar form and habits, they
were smaller and possibly more active. It is probable that fuller knowledge
of the fauna will record many more forms
related to this genus, and may prove that
forms known from areas as widely sepa-
rated from the Texas locality as New Mex-
ico, Illinois, and Pennsylvania should be
placed in distinct genera.

Acheloma. — This genus is known only
from the skull, a part of the pectoral girdle,
ribs, humerus, and an incomplete vertebral
column. We may not as yet attempt a
restoration or hazard a guess at its habits.
The peculiar form of the scapula-coracoids
is undoubtedly associated with some activ-
ity which we can not surmise. The anterior
ribs are expanded distally , probably for pro-
tection against some active predatory form.
1 1 probably did not exceed 800 mm . in length .

Trimerorhachis (fig. 14). — The genus is known only from the skull and a
few vertebrae. Some limb and girdle bones have been assigned to the genus,
but only tentatively. It is unfortunate that more is not known of Trimero-
rhachis, for it is one of the most primitive amphibians in the fauna. The skull
is longer than wide, with the nostrils at the anterior end and the eyes in the

Fig. 14. — Restoration of the head of Trimero-
rhachis sp. About one-half the size of an
average specimen.

128

THE rERMO-CARBONIFEROUS RED BEDS OF

anterior half of the skull. The clavicles were large and plate-like, and formed
some protection to the thorax. The vertebral colmim, composed of very thin
intercentra, pleurocentra, and neurocentra, with a very large inner space
for the notochord, must have been very weak and very flexible. The propor-
tions of the limbs are unknown, but any bones which can be assigned to the
limbs of the genus are relatively short and weak, with poorly developed ends
showing the presence of a large quantity of cartilage in the joints. It is
probable that the carpus and tarsus were also very weak, with few of the
bones ossified. We must think of this animal as probably slender, soft-
bodied, and salamander-like, with weak limbs and perhaps rather elongate
feet. The last idea is suggested by the probability that Trimcrorhachis was
largely aquatic, and progressed by swimming.

It probably lived in very much the same surroundings as the modern
mudpuppies, and probably had very similar habits. Large individuals may
have reached a length of i meter, but most of the skulls recovered indicate
a smaller size.

Zatrachys (fig. 15). — Known only from the skull, this genus can not
be restored, nor very fully discussed, but certain peculiarities of the skull
demand comment. The development of processes
on the edges of the skull, forming a sort of coarse
serration of the periphery, except on the anterior
end of the nose and the middle of the posterior
edge, is perhaps associated with the peculiarly com-
plex nature of the cranial sutures. The midline of
the skull is depressed and there are deep pits in
front of each orbit, which probably lodged some
sensory gland in life. The nostrils are far back from
the anterior end of the skull, and the space between
and anterior to them is peculiarly flat. Broom has
recently recorded his opinion that there is a median l:^;--
opening in the anterior end of the skull as in Tre- ^

° Fig. 15.

matops. While we can hazard no guess as to the

form of Zatrachys or its habits, we may be sure

that it was a highly specialized type, and was perhaps reaching that stage of

its development where approaching decadence is heralded by a development

of spiny processes. It may be a terminal member of some one of the many

branches of the great phylum to which Trimerorhachis belonged.

Dissorophus and Cacops (figs. 16 and 17). — The first is the most special-
ized of the three similar genera which are united in the family Dissorophidcc.
All of them have a more or less complete dorsal armor composed of the ex-
panded distal ends of the neural spines, alternating in position with overlying
dermal plates. In Cacops and Alegeinosaiirus, the armor was limited to the
midline of the back, and does not descend upon the sides of the body. In
Dissorophus the plates are longer, and came well down over the sides of the

Restoration of the head of
Zatrachys tnicroplhabnus Cope.
About one-half natural size.

NORTH AMERICA AND THEIR VERTEBRATE FAUNA.

129

body. The head was short, with large eyes and large auditory openings
which were covered by a tympanic membrane. The limbs were proportion-
ately long; the humerus of Dissorophus is nearly as long as the skull and the
femur fully as long or longer; the wrists, ankles, and feet were well formed
and strong, but rather broad, the tarsal and carpal bones being rather disk-
like, and without strong articular surfaces, as compared with the same ele-
ments in Eryops. The tail was short. The large eyes, well-developed audi-
tory sense, and proportionately long limbs show that these animals were

Fig. 16. — Restoration of Dissorhorphus multicinclus Cope. About one-fifth natural size.

probably more alert than most of the amphibians of their time, and capable
of rapid and sustained motion. It was probably just this alertness and
ability to get around which brought them into the danger from predatory
reptiles, and made armor necessary.

Cacops. — Williston has remarked upon the frog-like appearance of the
Cacops skeleton, especially shown in the large head and pectoral region, the
short neck and tail, and the posterior limbs longer than the anterior. He has

Fig. 17. — Restoration of Cacops aspidephorous Williston. About one-fourth natural size.

also shown that the toes were without claws, and suggests that the feet were
webbed, and that the animal was a good swimmer. The presence of armor
is no objection to the assumption that the animals were largely aquatic,
but the high development of the senses of sight and hearing, the evident
agility, and the location of the armor on the back, suggest that the animals
frequently sought the shore, and even ranged freely tipon the land. In the
water the attack would be at least as much from below as from above, and
the dorsal armor would have no special value, but on the land such small
creatures would be most likely to be seized from above, where even the begin-

130 THE PERMO-CARBONIFEROUS RED BEDS OF

ning stages of armor would prevent injury to the spine on many occasions.
The possibiHty that the armor may be considered as an evidence of a ter-
restrial habit has been noted above.

Abel, in his Paleobiologie, has suggested the correlation of dorsal armor
with fossorial habits in extinct amphibians and reptiles, but it could not be
the case with Cacops, which was devoid of strong claws.

Its habits were possibly similar to those of the Uving frogs, lurking in the
vegetation on the banks of bodies of water, sometimes wandering inland, but
always ready to make a quick rush to the protection of the water when danger
threatened. The total length did not exceed 45 centimeters.

Aspidosauriis (fig. 18). — This genus did not develop a dermal armor, but
the distal ends of the neural spines were expanded to a greater or less degree,
and undoubtedly furnished some protection to the animal. It is not probable
that the bony process projected for any distance above the line of back (un-
less it were in the case of Aspidosauriis crucifer). Any attempt to restore

Fig. 18. — Restoration of Aspidosauriis chiton Broili. Probably about one-fourth natural size.

these animals would be almost wholly conjectural. A. novomexicanus had
a skull similar in general proportions to that of the members of the Dissoro-
phid(B, but nothing more can be said with certainty. We can only imagine
it as a stegocephalian, with the general form of Cacops or Dissorophus, devoid
of any armor, but perhaps with a row of projecting knobs on the back.

Broiliellus. — In a recent paper Williston "^ has described a new amphibian,
Broiliellus texensis, from the Clear Fork beds of Texas. In this animal there
was a single row of dorsal dermal plates which were entirely free from the
ends of the neural spines, and the ends of the neural spines were not expanded.
This is the third type of armored amphibian in the fauna. Dissorophus has
the extremities of the neural spines expanded into overarching plates, and
this is overlain by dermal plates of similar form. Aspidosaurus has the ends
of the neural spines expanded without overlying plates. Broiliellus has the
dermal plates without any expansion of the end of the neural spines. Willis-
ton thinks that the expanded ends of the neural spines in Aspidosaurus are
really dermal plates which have become secondarily coossified with the neural
spines. The author has not held this idea and can not now accept it for all
cases. The only evidence he has that such an action may have taken place
is that in the Brier Creek Bone Bed he found a V-shaped dermal plate very
similar in appearance to the terminal process of an Aspidosaurus, but which

» Williston, Jour. Geol., vol. xxii, No. i, pp. 49-56, 1914.

NORTH AMERICA AND THEIR VERTEBRATE FAUNA. I3I

was evidently free from the neural spine during life. Very slight rugosities
on the lower side indicate a weak attachment to the spine. However, as this
plate occurs in the Wichita, and Aspidosaurus has never been found below
the Clear Fork, it is very possible that it represents a distinct form.

Trematops (fig. 19). — As suggested by Williston, Trematops must be a
close relative of Eryops, and there can be little doubt but that its habits were
similar. The head was proportionately larger, and shows some very different
structures, as the postorbital openings (closed otic notches), the elongate
nares, or nares united with preorbital openings and the median opening
between the premaxillaries. There can be little doubt that the anterior
median opening, and perhaps a part of the elongate openings which include
the nares, were the seat of glands of some sort, perhaps
connected with the lateral line system. What the use
of such glands could have been we can not conjecture,
but it is very possible that some sense was located in
them which we can not appreciate. In reading Dean's
accottnt" of the feeding habits of the Lung Fish, one is
impressed with the possibility that these lowly animals
may have had a totally different means of receiving
impressions from the external world than those which
we usually attribute to them.

The body of Trematops was not unlike that oi Eryops. Fig ig.-Rcstoration of the

-' ' "^ ' nead or / rematops niii-

Williston believes that it had a short tail, such as is leri wiUiston. About

, , ,. , 1 -1 • one-fifth natural size.

common m heavy-bodied amphibians.

Lysorophus (fig. 13). — This rather widely spread genus, found in Texas,
Oklahoma, and Illinois, was a slender, snake-like perrenibranchiate. Willis-
ton has found minute limb bones in the nodular masses which inclose the
skeletons of Lysorophus, and is inclined to believe that they belong to that
genus. This is not improbable, but it must be remembered that there are
other forms found in the same places and in the same nodules, and the limb
bones may have belonged to any one of the genera, or all may have possessed
them. The skull of Lysorophus is slender, but not long; rather more like an
Amphisbaenian or a CcEcilian than a snake. The vertebral column is long,
and is always found more or less perfectly coiled, a condition which led Baur
to suggest that they might be embryos. This is hardly possible, because of
the well-ossified condition of the vertebrcE and the skull, and is not accepted,
so far as I know, by any writer upon this animal.

If the creature did have limbs, they were very small and practically use-
less. If not snake-like, it was shaped like Proteus or Amphiuma, and was
very probably similar to them in habits (Williston). The skeletons are
found in great numbers in very limited localities, suggesting the gathering
together of large numbers of individuals in slowly drying pools, which in
their slow contraction forced the creatures together in large numbers in the

* Dean, Proc. Zool. Soc. London, 1906, p. 172.

1^2 THE PERMO-CARBONIFEROUS RED BEDS OF

last of the water. The fact that the bones are found in nodtilar concretions
or limy clay gives support to this idea of desiccation and the concentration
of the lime salts in the water. Associated with the skeletons of Lysorophus
are the skulls of Gymriarthrns, Cardiocephalns (?), and the form called by
Broili Diplocaulus pusilhis, but they are not at all common. No bones of
larger animals have been found with those of Lysorophus in Texas. It is
probable that all the creatures that could do so escaped from the drying pools,
but that Lysorophus, either because of its inability to leave the water or
because it sought protection by burrowing in the mud, perished in the com-
plete desiccation. If this idea seems probable, it may be accepted as con-
firmation of the amphibian nature of Lysorophus, for if it were a reptile it
would have been far easier for it to escape from such surroundings.

No skeleton recovered is sufficiently complete to warrant an exact esti-
mate of the length, but it certainly was not greater than 25 to 30 centimeters.
The author recognizes that Lysorophus is primitive in many respects,
but regards it as far too speciaHzed to occupy the ancestral position assigned
to it by Broili, and thinks of it rather as a very highly adapted member of a
primitive group, a terminal member of a side-line of evolution.

Crossotclos. — This genus has been found only in a single locality, Orlando,
Oklahoma, but occurs there in considerable ntimbers. It is possible that the
individuals suffered a fate similar to that of the members of the genus Lysoro-
phus. Far too little is known of the skeleton (only a part of the vertebral
column and a few limb bones) to enable any full idea of the shape or size to
be formed. It had a long tail, expanded in the vertical plane, and was con-
sequently a good swimmer. The limbs were of fair size. The chief peculiar-
ity of this genus is the development of large, thin dorsal and ventral processes
on the caudal vertebra;, and the closely inosculating, serrate spinal processes
of the dorsal vertebra. These structures are only matched in Osteocephalus
from the Linton beds, upper Pennsylvanian, of Ohio, Keraterpeton from the
Upper Carboniferous of Ireland {Scincosaurus from the Permian of Bohemia),
and UrocordyJns and Keraterpeton from the Permian of Bohemia. This
resemblance may be due to parallel evolution, but if so it is a very remarkable
case. Osteocephalus was elongate and snake-like in form, and Keraterpeton
was, as restored by Fritsch, a long-bodied, short-legged form, with a short,
round head, and a tail longer than the presacral portion of the body. ^ It is
probable that Crossotelos was not very different from the last-mentioned
genus in shape.

Cricotus (plate 20, fig. i).— This genus is the only known form from the
Permo-Carboniferous fauna which can be considered as having adopted an
active, predaceous, largely aquatic habit of life. The long and slender body,
terminating in a long tail with elongate chevrons and spinous processes, the
short limbs, with poor articular surfaces, and the elongate skull, with numer-
ous sharp, grasping teeth, all remind us strongly of the essentially aquatic
reptiles.

NORTH AMERICA AND THEIR VERTEBRATE FAUNA. I33

The large chevron bones and the elongate neural spines of the caudal
vertebras show that the tail was expanded vertically, and was a most efficient
organ of propulsion. What effect the embolomerous condition of the verte-
brae may have had upon the strength of the vertebral column we can not say,
but certainly it can not be regarded as a weak structure. The edges of the
faces of the deeply biconcave vertebral disks meet upon a plane and would
permit little lateral motion of the column, if there were not a considerable
mass of inter- and intra- (between the central and intcrccntral disks) verte-
bral cartilage. If this were lacking, and certainly the disks seem very closely
set together in the few series known, the body would have been more or less
stiff, like that of an Icthyosaur or a modern dolphin ; but if, as seems more
natural, there was a considerable mass of cartilage, the body would have had
great flexibility.

The animal probably moved with great swiftness, dashing upon fish and
smaller creatures, and seizing them in its powerful elongate jaws. A recently
discovered jaw indicates that the teeth were very small and recurved.

The partially complete skeletons in the American Museum of Natural
History are from 30 to 40 centimeters in length, but the larger species must
have reached a length at least twice as great.

In the recently discovered Brier Creek Bone Bed in Archer County,
Texas, great numbers of Cricotus vertebrae were found in association with
a fauna largely terrestrial, Dimctrodon, Edaphosaurus, Bolosaiiriis, Eryops,
and a few small amphibians, but no traces of sharks or fishes. If Cricotus
was largely aquatic in habit, as is indicated by its structure, this associa-
tion is difficult to explain.

Chenoprosopus. — Though this form is known only from the incomplete
skull, the shape of the head is so similar to that of Cricotus that we may be
fairly certain that it resembled it in the rest of the body, and occupied the
same position in the waters over what is now New Mexico in Permo-Carbon-
iferous time as did Cricotus in the more eastern region. It is perhaps signifi-
cant that the skull of Chenoprosopus was found in a deposit of river sandstones
and that no vertebrae at all resembling those of Cricotus were found in the
immediately adjacent bone beds which were formed in the quiet waters of a
pool. Were Chenoprosopus, and perhaps Cricotus, members of a group which
normally lived in large bodies of water, but which more or less frequently
ascended the streams in search of prey, occasionally dying in places rather
outside of their normal habitat, and leaving their remains among those of a
fauna to which they did not normally belong? If so, they give us a glimpse of
an open-water fauna of which we have no other knowledge, unless it be the
radically different Stcreosternuni and Mesosaurus of the southern hemisphere.

Mehl " has compared Chenoprosopus with Cacops and Archegosaurus, and
points out many resemblances. He is inclined to believe that the animal was
perhaps terrestrial, because of the lateral position of the orbits and the crush-

° Carnegie Inst. Wash. Pub. No. i8i, p. ii, 1913.

134 THE PERMO-CARBONIFEROUS RED BEDS OF

ing-teeth upon the palate adapted to the mastication of insect larvae and
small crustaceans. A lateral position of the orbits is not necessarily indica-
tive of terrestrial life, as is shown by their position in the Plesiosaurs, Icthyo-
saurs, etc. However, far too little is as yet known of this New Mexican form
to warrant extended speculation on its habits or form.

REPTILIA.
COTYLOSAURIA.

Diadectcs (plate 20, fig. 3, a and b). — This genus is representative of a
considerable number of less well known forms which were probably similar in
habits and in the shape of the body. Bolbodon, Chilonyx, Diadectoides, Baihy-
glypliis {?), and Desmatodon were all diadectid animals, but any attempt at a
restoration of any one of these must await further discoveries.

Diadectes probably reached an extreme length of 2.5 to 3 meters. Only
a few bones of the giant Diadectes maximus have been found, but that there
was such a creattire is known from vertebrae and limb bones. Diadectes
pliaseolinns, the best-known species, did not reach a length of more than 2
meters. The body was short and stout, with a tail equal in length to the rest
of the body. The limbs were extraordinarily heavy, and the humerus espe-
cially very broad, with powerful muscular articulations. The limbs ended
in wide, short feet, with stubby digits, terminating in broad nail-like claws.
The pectoral girdle was very strong, the bones being closely articulated,
but as a whole it was surprisingly narrow. From the spread of the ribs and
the general strength of the body, it might be expected that the fore-quarters
would be broad, but this is not the case; the fore-quarters were decidedly
narrow. The heav>' head, with its large, lateral eyes and large auditory open-
ings covered by a tympanic membrane, was set so close to the body that there
was apparently no neck. In restoring the skeleton of the animal, it was
found difficult to so arrange the bones that when the scapula was placed at
what seemed the most posterior point possible the angle of the lower jaws
would be free. The armor was confined to the anterior part of the thorax,
unless, indeed, there was a row of dermal plates upon the back, as suggested
above.

It is impossible to escape the idea that the animal was a very efficient
excavator, and though Williston has shown that it would be impossible or
very inconvenient for it to excavate a burrow, it might still have made use
of its powers in procuring a food-supply of roots or burrowing animals.

Diadectes was a sluggish, harmless creature, dependent upon its imper-
fect armor or upon concealment for protection. It moved with a sprawling
gait, the limbs standing well out from the body, which rested upon the ground.
There is no doubt that it could raise itself slightly from the ground, but it
was not possible for it to bring the limbs underneath the body, and walk
or run. As suggested previously by the author (Carnegie Inst. Wash. Pub.
145), it must have resembled to some degree the modern Ilelodcrma, especially

NORTH AMERICA AND THEIR VERTEBRATE FAUNA. 135

if the claws of that Hzard were made more nail-hke, and the tail more slender
and compressed vertically. It probably lived on the banks of streams, or in
the thick vegetation, seeking its food along water-courses or in damp spots,
and finding the vegetation a protection against the larger carnivorous reptiles.
The large eyes and the enormous, probably functional, pineal eye have led
to the suggestion that it may have been crepuscular in habit, with consider-
able powers of nocturnal vision, and came from its place of concealment only
when the shades of evening were dense enough to protect it.

The more the author studies the anatomy and probable habits of this
creature, the more he is impressed with the probability of his previous sug-
gestion that it was in many respects similar to the modern swamp and land
turtles.

Diadectoides was almost a travesty upon Diadectes. All the features of
strength and stoutness were exaggerated to a great degree. Its specific name,
cretin, was suggested by the dwarfish, overpowerful appearance of the imper-
fect skeleton.

Chilonyx had begun to develop a tuberculate condition of the skull like
that of the Pariesaurus of Russia or Elginia of the Scottish Trias. Bathy-
glyptus apparently was of the same type, but is so little known that no sug-
gestion as to its size or form can be hazarded.

Animasauras and Diasparactus. — These animals from the New Mexican
deposits were probably very similar to Diadectes in external form. Only the
skull of Animasauras is known. The exact form of the teeth has not been
made out in either, but the shape of the roots shows that they were similar
to those of Diadectes in a general way, and so indicate similar habits and food-
supply. They took the place in the New Mexican region that Diadectes
occupied in Texas. The possibility that Diasparactus was more primitive
than Diadectes is suggested by the fact that it has longer dorsal spines, with
no indication of a possible dermal armor of ossicles.

Limnoscelis (fig. 20). — This animal shows relations both to Diadectes and
Labidosaurus, as suggested by Williston. The form of the body and the
stout limbs were like those of Diadectes, but the shape of the head, the posi-
tion of the orbits and nares, the small pineal foramen, and the dentition
composed of conical teeth, with enlarged incisors in the upper jaw, are decidedly
reminiscent of Labidosaurus. As shown above, in the discussion of the food
habits and the aquatic adaptations, the animal was a dweller in the water.
Perhaps it was an aquatic branch of the same stem from which the terrestrial
diadectids rose. The structure of the vertebral column, the limb bones, and
the girdles are so similar in the two that we can not doubt that they had a
common ancestry. The modifications in the head, dentition, and feet are all
directly attributable to the adoption of an aquatic habitat.

The animal was about the same size as Diadectes phaseolinus, or a good-
sized Eryops, and resembled the latter in habits mvich more than the former.
The broad paddle-feet enabled it to swim rapidly and easily, and it could lie

136

THE PERMO-CARBONIFEROUS RED BEDS OF

concealed in the water, with only the nose and eyes exposed, as deeply as any
Eryops. It is possible that the great incisors were used, as has been suggested
for Labidosauriis, to excavate burrowing animals or detach clinging molluscs.
If this were true the animal would not have ranked with Eryops as a preda-
ceous form. Its main defense was its ability to take to the water freely, if

pjy 20.— Restoration of Limnoscelis paludis Williston. About one-tenth natural size.

attacked upon the land, or in its rapidity of motion if attacked in the water.
The great incisor teeth would have been no mean weapons if the creature
was driven to the use of them.

Bolosaiirm. — This was a small form, not over 30 to 40 centimeters in
length. From the imperfect skulls and associated limb bones and vertebrae,
it appears to have been a cotylosaurian, with a rather slender body, a long
tail, and rather moderately long ribs. The teeth resemble those of Diadcctes
closely enough to suggest that it fed upon insects and small crustaceans and
molluscs with weak shells. As noted above. Broom has suggested that Bolo-
saurus is not related to Diadectes.

Pariotichns, Isodectes, Ectocynodon.— These, with probably many other
related forms as yet undiscovered, were small lizard-like creatures which
Hved in the thick vegetation, or hid among the rocks to escape the larger
carnivorous forms.

Captorhinus (fig. 21). — This genus was very rich in individuals in Clear
Fork time. It reached a foot or more in length, including the not very long
tail. The head was large in proportion to the body, the limbs well formed
and terminating in strong feet with fairly long digits. It was active, and

Fig. 21.— Restoration of Captorhinus sp. About one-third natural size.

probably able to move with considerable rapidity for a short distance. The
position of the orbits and nares and the well-developed articulations of the
limb bones show that they were terrestrial in habit. Either upon the shores
or in the damp places of the land, they sought the small invertebrates, includ-
ing hard-shelled forms, upon which they fed.

NORTH AMERICA AND THEIR VERTEBRATE FAUNA.

137

Labidosaurus (fig. 22). — This animal shows somewhat the same relations
to Captorhinus that Limiioscclis does to Diadectes. It was a more aquatic
form, with a flatter skull, having the orbit and nares near the upper surface.
The teeth were far better formed and the carpus and tarsus better ossified
than were those of Limnoscelis. The tail was only moderately long. It is
probable that Labidosaurus was equally at home on the land and in the water,
but not capable of very rapid movement in either. Upon the land it must

Fig. 22. — Restoration of Labidosaurus hamatus Cope. About one-third natura size.

have occupied a prone position most of the time, and probably never rose to
a position so erect as given to it in Broili's reconstruction. The remains most
commonly found indicate an animal of a meter or less in length, but a few
skulls have been found which belonged to animals nearly twice that size. As
suggested in the discussion of the food habits, it probably fed tipon softer or
less well protected animals than did Captorhinus. The incisors were too
sharply turned backward to have ever been useful as weapons of offense or
defense, but would have been very efficient in extracting burrowing creatures,
or those hidden in cracks or crevices in the rocks, or tearing loose clinging
forms. Labidosaurus was one of the great group which clung to the margin
of the pools, or lived in the damp places among an abundant vegetation.

Seymouria (fig. 23). — -This is one of the most pvizzling of the Permo-
Carboniferous reptiles. It is so primitive in many of the characters of the

Fig. 23. — Restoration of Seymouria baylorensis Broili. About one-fourth natural size.

skull and skeleton that it is considered by Williston to be the nearest dis-
covered form to the connecting-link between the reptiles and amphibians.
The body was fairly plump, with strong limbs and rather slender digits, the
tail being relatively short. Williston detected certain flakes of bone scattered
through the matrix immediately adjacent to the bones, which he thinks are

138

THE PERMO-CARBONIFEROUS RED BEDS OF

possibly the remains of dermal scutes, but no abdominal ribs have been
detected, and he is certain that there were none. The movements were slow
and sluggish, probably similar to those of a land salamander. The "long
and slender teeth were utterly useless for the seizure and retention of large
prey. I think it very probable indeed that its food consisted in a large part,
probably wholly, of the smaller invertebrates, cockroaches, land molluscs,
worms, etc." (WilHston.)

Seeking protection and food in the deep vegetation, Seyinoiiria was sub-
ject to attack from carnivorovis forms, which would, as suggested for other
forms, grasp at it from above. This is, perhaps, the reason for the great
development of the neural arches, which, as Williston remarks, "form almost
a carapacial protection for the body."

Pantvlosauria.

Pantylus. — Nothing can be said of the form or size of this creature. The
skull alone is known, but served to show the presence in the fauna of a
typical, durophagous (conchifragous) animal.

Pelycosauria.

Varanosauriis and Vanuioops (fig. 24). — This is the best known of a
group of long, slender, probably semi-aquatic, lizard-like reptiles, with many
points in their structure which ally them with the Proterosaiiridcc. The skull

Fig. 24. — Restoration of Varaiwops brcvirostris Williston. About one-seventh natural size.

was more or less elongate, with sharp, conical, nearly isodont teeth. The
limbs and feet were well formed and fairly long, the carpus and tarsus well
ossified, the tail long and slender. They were probably able to move almost
equally well on land or in the water, and there is a suggestion of agility which
permits us to imagine them slipping with great speed through the under-
brush, as they sought their prey, or escaped from larger forms. With equal
ease and speed they may have glided into the pools or rivers, pursued or
pursuing, and flashed through the water as would a modern Varanus. Paleo-
hattcria, the nearest ally among the Protcrosauria, was far more clumsy in
its build, with much more cartilage in its joints and with weak feet.

Varanosaurus reached a length of a meter or more, and Pcecilospondylus
was about the same size. Thero pleura and Poliosaurus reached a greater
length, perhaps as much as 2 meters.

In New Mexico there were very similar, but generally distinguishable,
forms — Ophiacodon, Elcabrosaurus, and the creature originally described as

NORTH AMERICA AND THEIR VERTEBRATE FAUNA.

139

Dimetrodon navajovicus, but which certainly does not belong to that genus,
and has been called ArribasaurusJ^

Ophiacodon (fig. 25). — This creature is known from an almost complete
skeleton. The head was much more elevated in the facial region than in the
related Texas forms, approaching in that respect the genera Clepsydrops and
Dimetrodon from Texas. The peculiarly narrow skull, with the high and long
facial region, and eyes far up on the sides and near the posterior end, was
set at such an angle to the vertebral column that it was probably held rather
high. The teeth were sharp, compressed cones, with cutting edges, but nearly
isodont. The body was slender, with a tail as long as the body, and strong

Fig. 25. — Restoration of Ophiacodon minis Marsh. About one-seventh natural size.

limbs. The neural spines of the dorsal vertebras are somewhat elongated,
indicating the presence of a not very pronounced dorsal crest, as is suggested
in the restoration. The caudal vertebrae were without high spines or long
chevrons, indicating that the tail was cylindrical in form, and not of much
use in swimming. Probably the animal was more terrestrial than its relatives
in Texas. The total length of the single well-preserved skeleton is, as
mounted in the University of Chicago, about i meter; this includes the tail,
which is partly restored.

Thcropleura (fig. 26). — Much like Varanosaurus in most characters,
Theropleura was larger and stronger than that genus, with broader and heavier

r^t » '*>.

Fig. 26. — Restoration of Theropleura retroversa Cope. About one-tenth natural size.

limb bones. The dentition shows an approach to that of Clepsydrops and
Dimetrodon in the beginning of enlarged incisors and maxillary tusks. The
animal was evidently able to attack and hold active and vigorous creatures,
which it encountered, in all probability, in the water. One suspects that when

' Case and Williston, Carnegie Inst. Wash. Pub. i8i, p. 6, 1913.

I40

THE PERMO-CARBONIFEROUS RED BEDS OF

a Vaninosannis, or one of its kind, fled into the water to escape some prowling
Dimetrodon, it was in considerable danger of being devoured by its relative,
Thero pleura.

Spheuacodou. — From New Mexico came the scant remains of an animal
so like Dimetrodon in the structure of the skull that with the material at hand
it is impossible to distinguish the two genera by any cranial characters. The
dentition is in every respect the same, even to the enlarged incisors and
maxillary tusks, but as no vertebrae of this animal have been found with
dorsal spines more than 20 to 30 centimeters in length, it is apparent that
Sphenacodoii, while as active and fiercely carnivorous as Dimetrodon, lacked
the high dorsal fin. Perhaps it was even more to be dreaded by other ani-
mals, for the dorsal fin of Dimetrodon was most probably a serious hindrance
to rapid motion through the brush or high vegetation. It is very possible
that Sphenacodon, with dorsal spines just beginning to elongate, represents
the most active and efficient stage of the line which culminated in Dimetro-
don. The size of the animal is unknown, but one skull recovered is about
the size of that of a Dimetrodon of nearly 2 meters in length.

Clepsydrops and Dimetrodon (figs. 27 and 28). — The line of the carnivo-
rous, raptorial reptiles reached its greatest development in these two forms.

Fig. 27.— Restoration of Clepsydrops nalalis Cope. About one-sixth natural size.

In describing the amphibians and reptiles, constant reference has been made
to adaptations for defense, such as speed, agility, concealment, and armor.
Although the nearly universal rule of the fauna was to eat and be eaten, it is
probable that Clepsydrops and Dimetrodon were the most destructive forms
among the Permo-Carboniferous reptiles and probably the dominant cause
for the assumption of armor in their contemporaries. Clepsydrops was the
smaller and less specialized of the two. The grasping-teeth were shorter and
weaker; the incisors of the lower jaw did not lock so strongly between the
premaxillary and maxillary tusks; the limbs were fairly long, but not so
strong or well articulated as in Dimetrodon; the dorsal fin was not so high.
The weaker articulations have led to the suggestions that the animal was
aquatic in habit, but this is, at least, doubtful.

NORTH AMERICA AND THEIR VERTEBRATE FAUNA.

141

The skull was high and narrow, with a large facial region, and eyes far
back in the skull ; the body probably rather slender, and the tail long. The
extreme length was probably somewhere near a meter or a meter and a half.
The animal probably haunted the banks of pools and streams, or stole through
the vegetation, watching its opportunity to pounce upon some helpless or
unsuspecting prey.

In Dimetrodon the characters exhibited in Clepsydrops are developed to the
extreme. The morphological stages of development up to this highly preda-
ceous reptile are probably represented by Thcroplciira, SpJieiiacodoii, and
Clepsydrops. The most primitive of the active carnivores were isodont reptiles

Fig. 28. — Restoration of Dimetrodon incisivus Cope. About one-fifteenth natural size of an average speci-
men. The back of the animal in the picture seems to be a little too much curved, but is modeled after
the nearly complete specimen in the American Museum of Natural History.

like Poliosaurus and Varaiwsaunis, but as the necessity for seizing and holding
an active, struggling prey became greater, the powerful incisor and maxillary
tusks were developed, and the cheek-teeth of the skull and jaws became re-
curved, with sharp, serrate edges. There is no animal known, recent or fossil,
in which a more efficient apparatus for such cruel business has been developed.
With the increasing strength and size of the genus Dimetrodon, the limb
bones and feet became stronger and better developed. The animal probably
abandoned the aquatic habits of its ancestors and ranged very widely over
the land. As is apparent from the foregoing descriptions, the edges of the
pools were probably the regions most densely inhabited by amphibians and
reptiles, and no doubt such places were favorite haunts of the Dimetrodon.

142 THE PERMO-CARBONIFEROUS RED BEDS OF

The strong limbs, with longer foreleg than upper leg, and the strong feet,
with powerful claws, are ample evidence of an ability to run with some speed
and perhaps even leap or pounce upon prey. Abel, in his Paleobiologie,
points out that running and leaping animals have the foreleg longer than the
upper leg, and creeping animals have the proportions reversed. It is not
probable that Dimetrodon was ever capable of leaping any distance, but it
certainly was able to move swiftly for a short space. Probably it lay hidden
in the vegetation, and made short, scuttling rushes upon its prey, ending,
possibly, with a short pounce, which permitted its weight to add something
to the vigor of the attack by tooth and claw.

Several efforts have been made to restore Dimetrodon , but it has always
been difficult to make an illustration of the dorsal crest which appears at all
probable. That it was a thin, high fin, with the elongate spinous processes
united by a thin membrane of skin, I have little doubt. Abel and Jaekel are
disposed to think that the spines were covered by a skin, but not connected.
To the author this seems highly improbable. Aside from the possible evi-
dence furnished by the condition of Chamcleo crista tiis,'' there is little possi-
bility that such weak structures could long survive serious breakages without
the support of mutual connection.

The elongate spines were useless, so far as I can imagine, and I have been
puzzling over them for several years. The probable cause of their great
development is discussed upon a preceding page. It is impossible to conceive
of them as useful either for defense or concealment, or in any other way than
as a great burden to the creatures that bore them. They must have been a
nuisance in getting through the vegetation, and a great drain upon the crea-
ture's vitality, both to develop them and to keep them in repair. The genus
succeeded despite of them, or perished because of them.

The presence of several species and large numbers of individuals indicates
that the genus was for a time at least successful, but this success probably
resulted from a dominance attained before the dorsal fins reached their full
size; from then on the spines became a burden and a possible cause of decline,
as suggested above.

The most common species, D. iiicisivus, reached about 2 meters in length.
No specimen has as yet been found with a complete tail, but the rapid decrease
in size of the caudal vertebra suggests only a moderate length. D. gigas,
the largest known form, must have reached a length of at least 3 meters,
and, probably, single individuals were even longer.

Edaphosauria.

Edaphosaurus (fig. 29). — No single animal of the Permo-Carboniferous
fauna has been so much discussed or so greatly misinterpreted as this one.
Because of the possession of elevated dorsal spines the skeleton was very
naturally placed close to Dimetrodon, and it was restored with limbs, skull,

* Case, Science, vol. xxix, p. 979, 1909.

NORTH AMERICA AND THEIR VERTEBRATE FAUNA.

143

etc., appropriate to that genus. The skull, long considered as belonging to a
totally different type of animal, the scapula, pelvis, and the proportions of
the limb bones have all been shown to be radically different from those of
the Dimetrodon. The skull was rather short and high, with large orbits near
the middle. The teeth upon the edges of the jaws are conical, with accessory
crushing-teeth upon the palate and dentary. The scapula was very broad
and heavy. An isolated scapula of this form was found many years ago by
the author and supposed to belong to a diadectid, but, as has recently been
shown by Case and Williston,'' probably belongs to Ednphosaiirus.

The limbs were shorter than in Dimetrodon, owing largely to the short
fore limb, indicating a creeping habit and much slower motion. No foot
bones have been certainly associated with this genus. A very large, claw-like

1!' f':Jl'l*'/,/^.'^i^:

.A^Bi

Fig. 29. — Restoration of Edaphosaurus criiciger Cope. About one-tenth natural size.

ungual phalanx is associated with a specimen in the American Museum, and
well-modeled tarsal and carpal bones, not assignable to Dimetrodon or Dia-
dectes, have been found in the Brier Creek bone-bed, associated with bones of
Edaphosaurns, but the evidence is too imsatisfactory to be accepted without
question. It is not improbable that the feet were strong, and provided with
powerful scratching or digging claws.

The dorsal spines differed somewhat in the different species. In Edapho-
saurns claviger the spines of the cervical vertebrae were expanded and clavate
at the top; in Edaphosaurns cruciger they were very little or not at all ex-
panded. The dorsal spines began immediately behind the skull, rose rapidly
to their full height, and continued to the pelvic region, where they terminated
abruptly. The spines of the first caudal vertebrae are abruptly reduced in

•Carnegie Inst. Wash. Pub. 181, p. 78, 1913.

144 THE PERMO-CARBONIPEROUS RED BEDS OF

height to a few centimeters, and he beneath the spines of the sacral and
posterior lumbar vertebras, which curved abruptly backward. The length of
the tail is unknown, but it was probably fairly long. The genus was rich in
individuals and several species have been identified. The remains are not
uncommon, but almost always consist of the fragments of spines, or complete
isolated spines. This condition of the remains has been regarded as indi-
cating that the animal's habitat was rather far from any place where the
body could be easily embedded, and that it was disintegrated by carrion
feeders, decay, or transportation for some distance, before burial.

Edaplwsaurus was a slow-moving, harmless creature, feeding upon small
invertebrates of all sorts and possibly vegetation. The powerful claws, if
they belonged to this animal, would have been useful in digging in the soft
earth or vegetation, or in tearing open decayed stumps and logs in search of
insects, etc. If, as suggested, its habits confined it more to the upland, away
from the waters and the abundant vegetation, it was perhaps beyond the
ordinary range of the fierce carnivorous forms, and so found the peace and
full nourishment which permitted the development of the enormous spines
as a physiological excess.

The largest known specimens would have a length of about 2 meters, if
we assume that the tail was as long as the rest of the body.

The single imperfect skeleton discovered in New Mexico, and described
as Edaphosaurus novomexicanns, is, so far as it is known, very similar to those
recovered from Texas. The imperfect skull shows the same form and the same
arrangement of the teeth. The dorsal spines are more slender, with fewer and
less well developed tubercules. Of the appendicular skeleton little is known.
The conformation of the cervical vertebrae, as suggested by Williston, would per-
mit the head to be thrown far down and even bent under the body, an attitude
which would bring the anterior spines forward. If this is correct, it is the
first hint of a vise, defensive or otherwise, which has been found for the spines.

The single small fragment described as Edaphosaurus (Naosaiirus) ray-
mondi, from near Pittsburgh, is far too uncertain to use as a basis of any
conclusion. It is not improbable, however, that EdapJiosaitrus ranged over
the eastern United States, if, as supposed, it was an upland animal, and as
its remains have been found in eastern Europe.

Platyhistrlx. — -In New Mexico there are found the remains of another
long-spined creature, as yet but little known. The spines are shorter than
those of Edaphosaurus, but are very large for the size of the vertebra and
very rugose upon the sides. The shape, size, and character of the skvill and
teeth are all unknown. We have here but a glimpse of another long-spined
form which remains to be worked out.

Caseasauria.

Casea (fig. 30). — The head of this remarkable creature, as described and
figured by Williston, was short and broad, with a flat or even slightly con-

NORTH AMERICA AND THEIR VERTEBRATE FAUNA.

145

cave top, and a pineal opening even larger, proportionally, than in Diadectes.
The large eyes were on the side of the head ; the nostrils on the lower side of
the blunt, projecting snout, and directed downward and forward. The body
was quite broad, with well-developed ribs on nearly all of the presacral verte-
brae. The limbs were strong, the anterior the longest, terminating in broad,
stout feet. The tail was long and very slender. The teeth upon the edges of
the jaws are few and blunt, leading Williston to the conclusion that it was
phytophagous and moved slowly over the flat river plains, "perhaps feeding
upon succulent meadow vegetation." Aside from the fact that a study of the
possible food-supply does not afford any evidence of a suitable vegetation,
the teeth seem to be fviUy as well adapted to a diet of soft or protected
invertebrates.

The large eyes, enormous pineal foramen, and the well-developed sense
of smell indicated by the large nasal cavities, together with the evident help-
lessness and lack of speed, suggest that the animal was dependent for its

Fig. 30. — Restoration of Casea broilii Williston. About one-tenth natural size.

safety upon concealment, or nocturnal habits. Williston has also noted that
the broad, squat body is such as coinmonly occurs in desert reptiles, and sug-
gests that Casea may have lived in dry and heated localities.

Areoscelid.^.

AreosccUs (fig. 31). — In the descriptions attempted above most of the
animals have been found to be dwellers in the "lower jungle" or in the water.
A few appear to have been dwellers on the higher lands. But a single genus,
Areoscelis, has been recovered to show that there was a life of the "upper
jungle." The remains described by Williston are those of an animal possess-
ing extraordinarily light and slender bones. The skull and girdles are too
imperfectly known to discuss, but the bones of the limbs are very long^
hollow, and light, without evidence of the attachment of powerful muscles.
In every way the skeleton suggests great speed and agility, equaling in this
respect any living lizard. The bones are those of a swift terrestrial, or, more
probably, arboreal creattire. The branches of the great lycopods, or of the

146

THE PERMO-CARBONIFEROUS RED BEDS OF

larger fern-like plants, probably formed its home, from which it descended
to fly with lightning speed to some other place of refuge or to seek its food,
which very possibly consisted, in part at least, of swift flying or crawling
insects which the slower reptiles could not capture.

Williston estimates the length of Arcoscelis at about 75 to 80 centimeters.
Though this is the only known form supposed to have led an arboreal life,
we can not doubt that there were many more whose remains we can never

Fig. 31. — Areoscelis gracilis Williston. About one-seventh natural size.

hope to find, unless a few of them come to light, preserved by similar acci-
dents to those which brought the bodies of a few individuals of the genus
Areoscelis into the bone-bed where they were preserved. There was, in all
probability, an abundance of terrestrial and arboreal life which will never be
revealed to us."

» Williston has very recently (Jour. Geol., vol. xxii, No. 4, 1914) published a more complete description
of Areoscelis, in which he asserts its relationship to the Lacertilia. " I have no hesitation in saying that the
skull and skeleton of Areoscelis present distinctly primitive characters of the Squamata, to such an extent
that I believe the genus has a definite phylogenetic relationship to the order."

NORTH AMERICA AND THEIR VERTEBRATE FAUNA. I47

RESTORATION OF THE REGION AND ENVIRONMENT IN WHICH THE

ANIMALS LIVED.

In the preceding descriptions only the better-known forms are included.
Many more are known from incomplete skeletons, solitary bones, or frag-
ments, which would not warrant any attempt at restoration. Probably
many more forms will be discovered in the Permo-Carboniferous beds, but a
large proportion of the fauna may never be known. Enough has already
been made out to show that it was abundant and most complex.

Considering only the region in Texas and Oklahoma, which is typical of
all the Red Beds, we may restore in imagination a great flat land stretching
away from the Wichita Mountains and the Arbuckle Hills to the east and
south, where it joined the ocean waters. The western border of the fiat we
do not know. The normally semiarid condition of the land was interrupted
by incursions of the sea and fluctuations of the climate to more humid condi-
tions. The aridity never attained a degree which prevented the growth of
some vegetation or the presence of pools of water and running streams, but
was sufficiently intense, at times, to prevent the accumulation of much vege-
table debris in swamps or stagnant lagoons. In the times of increased
humidity the vegetation increased in quantity, the waters accumulated in
large areas and were overshadowed by a heavy growth, and the streams
expanded and spread over their flood-plains, leaving masses of irregularly
bedded sandstone and clay. It would perhaps express the ideas of the author
a little better to speak of the great fiat as being particularly well drained in
the times of greatest aridity, with the water-table low, allowing a free cir-
culation of water and air. In the more humid periods the water-table rose,
and the circulation of the air and water was prevented. Even in the times
of greatest aridity it must be supposed that there probably were seasonal or
other changes of small period which brought enough moisture to keep the
land far from a true desert condition.

Upon this fiat, largely around the pools and streams, lived the wonder-
fully complex amphibian and reptilian life. The waters swarmed with fish
and amphibians, and were constantly invaded by predaceous reptiles in
search of food. In the quieter pools and back waters of the streams lurked
the great Eryops and its lesser relatives, ever ready to rush from their con-
cealment upon any unfortunate creatiires that ventured too near. In the
open waters of the stream Cricotus opposed its strength to the current,
spending its time in active search and open attack upon its prey. Burrowing
in the mud, or creeping slowly along the slime at the bottom of the water,
were such forms as Lysorophus, Diplocanlus, and a host of forms with similar
habits. The slender Varanosaurus or Theropleura shpped quietly into water
and swam slowly until the sight of some victim caused it to leap into activity
and follow its prey with lightning speed at the surface or beneath the waters.
The banks of such pools and streams must have been arustle with the shifting.

148 THE PERMO-CARBONIFEROUS RED BEDS OF

hiding, searching creatures. The harmless Dissorophus, Cacops, Seymouria,
and diadcctids scratched and grubbed among the leaves and in the soft earth
after worms, larvas, and small creatures of all kinds, or at the water's edge
overturned stones and tore apart the rotting stumps of the great lycopods in
the same search. Some of these forms were undoubtedly very sluggish and
sought their food or endured their fate with an equal stolidity, but others
were alert, and on the approach of some carnivorous reptiles there was a
sudden dash for the water. Scrambling throvigh the weeds, slipping from
convenient logs or stones where they had been sunning themselves, seeking
the deep water in the quickest way, the smaller creatures fled the larger ones.

The terror of those banks must have been the great Dimctrodon. With
speed, power, and an armatiu-e of teeth far ahead of any creature of its time,
its progress must have been one of devastation. Fearing only individuals of
its own kind, the only need for care in its motion was to avoid disturbing the
prey before it was sufficiently close to warrant the last dash. When once the
great teeth had seized the animal there was no escape. Clepsydrops, in the
water or always near it, and Dimctrodon, haunting the higher land or the
water's edge, were the tigers of their time. There must have been some nota-
ble battles in those woods. The skeletons of Dimetrodon very frequently
show the marks of fracture and healing in the slender spines, undoubtedly
the results of sanguinary conflicts over victims or for mates.

On the higher lands, on the banks of the pools, perhaps even upon the
shores of the invading seas, the diadcctids, £Ja^/zo.w//r//5, and Pantylus sought
the hard-shelled molluscs and other animals, or the vegetation which served
them as food. That Diadectes, at least, was not free from attack, is shown by
the beginnings of a defensive armor. Edaphosaurus, if the author's ideas are
correct, had found some form of protection or isolation which permitted it to
develop in comparative peace and safety.

Among the trees and bushes moved Arcoscelis, undoubtedly with many
accompanying forms of which we have no knowledge.

The composition of the complex fauna undoubtedly changed with the
changing climate. Periods of drought would drive some of them out, or
cause the death of large numbers which .sought shelter in the desiccating
pools. Recurring humidity brought back the life again. The passage of
years also brought its changes. Forms familiar in the lower beds are absent
above, and new forms come in. It is probable that this was, in part, due to
the extinction of old forms and the evolution of new, but there can be no
doubt that the conditions during Clear Fork time were decidedly different
from those of the Wichita, and the altered composition of a fauna is as
frequently the result of migrations as it is of evolution.

Another thing that must be constantly kept in mind is that the remains
are not fotind in their natural habitat. In only a few cases can it be shown
that the animals have been buried near where they lived or died. Rivers or
currents in larger bodies of water have borne the carcasses away after death,

NORTH AMERICA AND THEIR VERTEBRATE FAUNA.

149

and in any attempt to picture the natural habitat this must be reckoned
with. The deposits in which the skeletons are found are not the same in
form and composition as those among which the animals lived. The material
has been transported at least as far as the skeletons and has suffered much
alteration.

Table 3. — Showing forms in New Mexico and Texas which exhibit parallelism or relationship in structure

and habits.

[Forms marked with a question mark (?) may later be recognized as distinct genera, but as yet there is

insufficient evidence.]

Texas.

Diplocaulidas

Eryopidas

Eryops

Trimerorachidae . . .

Zatrachida;

Dissorophidae

Aspidosauridas . . . .

Aspidosaurus .
Trematopsidae . . . .

Ly sorophidae

Gymnarthridae. . . .
Cricotidas

Cricotus

New Mexico.
Eryops (?).

I Texas.

Diadectidae

Diadectes. . .

Aspidosaurus (?).

Clienoprosopus.

Bolbodon . . . .

Chilonyx

Diadectoides .

Bolosauridae

Pariotichida2

Captorhinidac

Captorhinus .

Labidosaurida;

Labidosaurus ....

Seymourida;

Pantylidas

Poliosaurida2

Poliosaurus

Varanosaurus. . . .

Poecilospondylus .

Theropleura

Caseidas

Areoscelidae

Clepsydropidae

Clepsydrops . . . .

Dimetrodon . . . ,
Edaphosauridae

Edaphosaurus .

New Mexico.

Diadectes (Nothodon).
Diasparactus.
Animasaurus.
LimnosceHs."

Several small unde-
scribed bones (?).

LimnosceHs.

Ophiacodon.
Elcabrosaurus.
Arribasaurus.
Scoliomus.

Clepsydrops (?).

Edaphosaurus (?).
Platyhistrix.

• Limnoscelis may be nearer to Labidosaurus.

CHAPTER IX.

RELATION OF NORTH AMERICA TO THE OTHER CONTINENTS IN PERMO-

CARBONIFEROUS TIME.

The Permo-Carboniferous fauna has been traced from New Mexico to
Prince Edward Island, but has not been recognized with any certainty in the
European Permian, as shown by Case.^ The only European genus which has
been recognized as belonging to the Texas fauna is Edaphosoiiriis, described
by Fraas from Bohemia and by Jaekel from the vicinity of Berlin.'^ Von
Huene has described two forms, Anomosanrus and Ctenosanrus, which he con-
sidered as related to the Pelycosaurs, but which, occurring as they do in the
middle and upper Triassic, can be regarded only as widely removed descendants,
if related at all.^

The resemblance of Crossotelos to Urycordylus and Keraterpeton can not

be considered as genetic.

The fauna of North America was, so far as the author can see, an isolated

one, prevented from any mixture with other groups of animals by an isolation

of the continent from Europe nearly as complete as that of to-day. The

author is in accord with Williston in this matter, who in 1909 expressed him-

,self concerning the fauna as found in Texas as follows:'^

"As a continent I believe that the land of America was absolutely and continu-
ously isolated, so far as the intermigrations of land forms were concerned, from some
time before the close of the Pennsylvanian till well into Triassic times, as they reckon
in Europe.

"The fauna was literally sui generis, and I may almost say sui ordinis. But
two or three genera of two types out of the scores of genera known from these
regions can be correlated as showing resemblances — family resemblances, I rnean —
with foreign forms. And both of these types had made their appearance, admittedly
nowhere in America, before the close of the Pennsylvanian, one the derivation of
Upper Carboniferous, possibly sub-Carboniferous stock, the other a later develop-
ment, and both continuing for a brief period in Europe during the Permian times.
Of all the remainder of the air-breathers not one can be compared with forms known
elsewhere in the world, save in general characters — ordinal characters at best.

"These facts can mean but one thing: the faunal isolation of land and fresh-
water vertebrates during all of the so-called Permian times in America. * * *

"Upon the whole, then, our Permian fauna is sharply, and almost completely,
distinguished from any supposed contemporaneous or indeed any fauna known
elsewhere, and may have been evolved wholly in America from known Pennsyl-
vanian forebears."

« Case, Jour. Geol., vol. xxvi, No. 6, pp. 572-580, 1908.

>> Jaekel, Naosaiirus credneri, in Rothliegenden v. Sachsen. Monatsb. d. Deutsch. Geol. Gesellsch.,
1910, Nos. 8-10, pp. 226-535.

<^ Described and discussed in Carnegie Inst. Wash. Pub. 55, pp. 33-57-
<^ Williston, Jour. Geol., vol. 17, p. 389, 1909.
150

NORTH AMERICA AND THEIR VERTEBRATE FAUNA. 151

Whether there was as complete an isolation in the earlier stages, repre-
sented perhaps by the New Mexican fauna, the author is less certain. The
similarity of the Poliosaiiridce to the Protcrosanria is so striking that a com-
munity of European and North American forms is suggested in the lowest
Permo-Carboniferous or late Pennsylvanian. Edaphosaurus crediierl is dis-
tinguished by Jaekcl from later forms by the sparse projections upon the
spines, a character also noticeable in Edaphosaurus novomexicanus from the
New Mexican beds.

There are three possibilities of a connection between North America and
the other continents: Either with the Europe-Asia continent by way of the
North Atlantic continent ; to the south with Gondwana land by way of a land-
mass where Central America now lies; or across the Bering Straits with Asia.

The possible connection with Europe-Asia will be first considered. Suess,
Freeh, De Lapparent, Netimeyer, and others have demonstrated the presence
of a great east-west chain of folded mountains across France and Germany,
reaching into southern England, Wales, and Ireland, which was uplifted in
Carboniferous time, and again viplifted after profound degradation in Per-
mian time. This is the great Hercynian chain, or Paleozoic Alps, composed
of an eastern, Variscan, portion in Germany and southern Russia, and a
western, Armorican, portion in France and Great Britain. The western ends
of the Armorican folds end abruptly at the Atlantic borders, or disappear
beneath it. On the opposite side of the Atlantic similar folds appear in New-
foundland, with equal abruptness, and are correlated with the Appalachian
folds to the south. The sudden ending of the folds in a rias coast is accepted
as evidence of their previous continuity across the ocean in the old North
Atlantic continent which probably disappeared in the great movements of
the Mesozoic.

The presence of a great North Atlantic continent in Carboniferous and
earlier times is accepted as a proved fact by all the writers upon the subject,
and need not be defended here. The reader will find discussions of the sub-
ject by the following authors :

De Latmay, La Science Geologique (chap, xii, p. 500), speaking of the
Stephanien, says:

"Enfin, aux Etats-Unis, des accumulations de vegetaux se font egalement sur
des cotes a I'Ouest des Appalaches dans rillinois, I'Arkansas, le Kansas; une chaine,
homologue de la chaine hercynienne et qui la prolonge peut-etre, au Nord de notre
Mer Interieure, au Sud de notre grand sillon houiller, surgit dans les Appalaches."

On a map opposite page 498 De Launay gives his idea of the paleography
of Westphalien time. In this he shows a land-mass occupying the whole
North Atlantic area, and connecting Europe with North America.

In a map at the end of the book he shows the northern hemisphere, with
indications of the Hercynian folds reaching far out into the Atlantic Ocean
from both the eastern and western sides.

152

THE PERMO-CARBONIFEROUS RED BEDS OF

Suess, in his Face of the Earth, volume ii, page 97, gives an account of
the rias coast of Brittany and Newfoundland, and on pages 201 and 202 of
the same volume, a general account of the rias coasts of North America
and Europe. On page 202 of volume 11 he gives in some detail the evidence,
from the character and position of sedimentary beds, for a North Atlantic
continent.

Freeh, in the Lethea Paleozoica, volume 11, page 402, with map v in the
accompanying atlas, describes the broad land-mass reaching from central
France and southern England across the North Atlantic in Upper Carbonifer-
ous time. The statement is made both by Freeh and Suess that the elevation
of this land-mass had little or nothing to do with the various minor movements
of the sea over Europe in Carboniferous and Permian time.

Arldt, in his work, Die Entwicklung der Kontinente und Ihrer Lebewelt,
says, on page 577:

"Im Perm sind die Altersbestimmungen verschiedener Schichten besonders
der sudlichen Hcmisphare noch zu unsicher, urn die Rekonstruktion einer palao-
geographischen Karte zu gestatten, die einigen Anspruch auf Richtigkeit hatte.
Im unteren Perm hatte die Nordatlantis etwas dieselbe Ausdehnung wie ini oberen
Karbon, doch war das Davisbecken jedenfalls nach Siiden noch etwas weiter ausge-
dehnt, so dasses mit dem nordatlantischen Becken durcheine schmale Meeresstrasse
in verbindung trat und die Nearktis vollstandig von der Nordatlantis abtrennte. Die
Nearktis hatte sich westwarts etwas ausgedehnt, doch war Kalifomien noch Meeres-
gebiet. Nach Siiden zu trat die Nearktis mit der Siidatlantis in verbindung und
schnitt so das nordaltlantische Meer von dem Grossen Ozeane ab."

And on page 575:
"Grossartig war der Gebirgsfaltungsprozess der in der Mitte der Karbonzeit
einsetzte, wobei die Gebirge in der Hauptsache den Randern der Kontinente folgen.
Den Siidrand der Nordatlantis bezeichnete das langste und bestbekannte der dama-
ligen Gebirge, das durch siidnordlich gerichteten Druck an den Kontinent angescho-
ben wurde. Seine westlichen Spuren finden wir in den karbonischen Diskordanz des
Felsengebirges. Weiterhin steigen die Appalachian empor und inf olge dieser Hebung
trat die oben erwahnte nordamerikanische Regression ein. Das Gebirge fiihrte nun
uber den jetzigen Ozean und setzte sich in den aremorikanischen Ketten fort, die
in Mittelf rankreich mit den variskischen zusammenscharten und durch ihre erhebung
die Regression in Mitteleuropa bedingten."

While many other authors might be cited to prove the general consensus
of opinion that such a continent existed, these works contain the collected
evidence and seem sufficient.

Just what the condition of this continent was in Permian time seems less
certain. As quoted above, Arldt believes that a southern extension of the
Davis Strait cut across the North Atlantic land and separated the eastern
and western land-masses.

Freeh (Lethea Paleozoica, vol. 11, p. 662) says that little can be said con-
cerning the North Atlantic continent in the Permian. De Lapparent (vol. 11,
p. 1025) mentions the occurrence of Schizodus sdotheirni and Aucella hausmani

NORTH AMERICA AND THEIR VERTEBRATE FAUNA. 1 53

in Nova Scotia, and on page 1018, in a map of the Tluu-ingien, shows an arm
of the sea reaching across from north of England to Nova Scotia.''

Koken (Festband der Neues Jahrbuch hxr Mineralogie, Geologic u.
Paleontologie, 1907, p. 525) says that the Zechstein deposits of Nova Scotia
(the locality of Schizodus and A ucella mentioned above) are outlying deposits of
the Arctic Ocean. De Lapparent (according to Koken) would have the deposit
connected with the Paleozoic Mediterranean (see the map of the Thuringien
cited above), but this is not borne out by the fauna. There is a possibility,
despite the lack of connecting sediments, that it was connected with the
western American province. The decision must be made in the future. We may
still be certain, in any case, of the presence of a North American-Greenland-
North European land-mass.

From the foregoing citations it is apparent that the site of the North
Atlantic Ocean was occupied in pre-Permian time by a great land-mass. The
condition of the land in the Permian is uncertain, but there were possibly
some breaks across it, as the Davis Strait, which would constitute a barrier
to migrations between Europe and North America.

On the eastern land-mass the Hercynian chain completed its develop-
ment before the Permian time, was eroded, and re-elevated in the Permian.
On the western land, the Appalachian Mountains were not elevated until
the later part of the Permian. If, as is probable, the Appalachians were
elevated by a great world movement which was manifest earlier in Europe
as the Hercynian chain (Armorican-Variscan) and progressed toward the
west, it is probable that the North Atlantic continent carried the connecting
link in the late Carboniferous and Permian. The ends of the links are seen
in the rias coasts of Great Britain, France, and Newfoundland. That no
remnants of the mountains are found by soundings in the North Atlantic is
not surprising, for even if the great basin was formed in Mesozoic time, the
previous exposure was sufficiently long to wear the mountains down to low
altitude. Witness the reduction of the Appalachians to a peneplain condi-
tion by Jvirassic or early Cretaceous time.

Either a break in the North Atlantic continent or the presence of high
mountains would have been an efficient barrier to the migrations of the
Permo-Carboniferous reptiles and amphibians, and either or both of these
geographic features occurred in late Carboniferous or Permian time, on the
land connection between Europe and North America, permitting the migra-
tion of the earlier Carboniferous or Permo-Carboniferous forms and isolating
the later and more specialized forms.

The possibility of migration was again established in the Triassic, as
shown by an abundance of common forms.

The possible connection with South America has been suggested by
Broom, who believes that somewhere in that continent the common ancestors

" The author has been unable to trace the origin of the statement of De Lapparent. It may be taken
from Geinitz, K. Leopold, Carolin. Acad., Bd. 33, 1866.

IS4

THE PERMO-CARBONIFEROUS RED BEDS OF

of the African and North American faunas were developed, and that there
was a dispersal of the fauna from a common center. Broom says:""

"Taking all the facts into consideration, it seems to me probable that in Upper
Carboniferous times there appeared in the northern part of South America a primitive
land vertebrate fauna, comprising among other types temnospondylous amphibians,
primitive cotylosaurians, and primitive ancestral Pelycosaurs. Before the conclusion
of the Carboniferous period, this South American fauna invaded North America, and
almost immediately afterwards the northern group became isolated. The isolation
continued during at least the whole of the Lower Permian times, and these isolated
types became greatly specialized in their struggle with some adverse conditions.
What the conditions were we do not know% and no satisfactory explanation has, I
think, been given of the development of the enormous spines of the vertebrae in the
Pelycosaurs. Nor do we know what caused the extinction of the whole fauna about
the Middle Permian rimes, but most likely some change in cUmatic conditions.

"In South Africa the first Karroo reptile to appear is Mcsosaitrus, which is
found in beds a little above the Dwyka tillite. It is certainly generically similar to
the Mcsosaitrus of Brazil, and closely allied specifically. This occurrence of Meso-
sanrus on both sides of the Atlantic, as well as a series of plants which are specifically
identical in Brazil and South Africa, renders it practically certain that there was a
land connection between South America and South Africa in Lower Permian times,
and that animals might have migrated from what is now the one continent to the
other. There is, however, no evidence that any reptiles other then Mcsosaurus
arrived in South Africa till some considerable time after the origin of the Permian.
Perhaps the reason for this may be that al^out the beginning of the Permian period
South Africa, and probably much of South America, Australia, and India were,
from some cause or other, largely covered by glaciers, and possibly for long afterward
the climate was too severe to allow the more northern or equatorial types to invade
the south. In beds which are called Ecca we get the earliest immigrants— a large
carnivorous reptile called Archcosuchus, which may have been a dinocephalian, and
evidence from a tooth of a large undoubted dinocephalian which was a herbivore.
It is, however, not till Middle Permian times that the fauna becomes rich. Then
there appear pareiasaurians, a considerable variety of dinocephalians, many thero-
cephalians, a few anomodonts, the only known dromasaurians, and a temnospondy-
lous amphibian. Where this great collection of forms came from is, of course, un-
known. They can hardly have originated in South Africa, because though the lower
Permian beds are lithologically exactly similar to those of later Karoo times, they
are almost entirely unfossiliferous.

"It seems to me, however, probable from the general resemblance of the African
fauna to the North American Permian, that both have come from the common
source, which I believe must have lived in the northern part of South America.
After the invasion of North America in Upper Carboniferous times, all connection
between North and South America ceased for a very long period. The near relatives
of the ancestors of the North American Permian forms left in South America evolved
on quite other lines. For long they were probably confined to the Brazilian region,
owing to the cold prevailing in the South, but ultimately they spread down and
across the South Atlantic into Africa, where they for the most part arrived during
the Middle Permian times."

If such a connection, as supposed by Broom, existed between North and
South America, it must have been in or before Pennsylvanian time. Deposits

» Broom, Bull. Amer. Mus. Nat. Hist., vol. xxviii, art. xx, p. 233, 1910.

NORTH AMERICA AND THEIR VERTEBRATE FAUNA. 155

of undivided Carboniferous are found in Nicaragua and Honduras,'' and rocks
of Pcnnsylvanian ^ and Mississipian age occur in Chiapas, Guatemala.

Koken," in his map of the Permian, shows the sea extending across the
Central American area, apparently on the evidence of Fusilina found in
British Honduras and Chiapas.

No Permian deposits have been found in Central America, but the
Guadalupian fauna of Girty shows that there was a body of water over
trans-Pecos Texas and a portion of southeastern New Mexico, in Permian
time, which was connected with the European Permian seas. If the animals
of this sea were derived, as is possible, from a Mediterranean Tethys, the
isolation of North America from South America is certain and demonstrated.
If, as Koken has suggested, the fauna reached the site of the Guadalupian
Mountains through the Pacific rather than through a Mediterranean sea,
there still remains the evidence of a sea across Central America in the Fnsi-
linas of British Honduras and Chiapas.

It seems to me far more likely that the North American fauna originated
in the northern land-mass, developing from some such forms as Sauravus
costei Thevenin, from the Stephanien of France, and Eosauravus copei
Williston, from the Linton coal-beds of Ohio, and spread freely in late Car-
boniferous time after a considerable evolution, such as is suggested by the
faiina of the Pittsburgh shale. Of this fauna we have representatives in the
specialized Proterosauria of Europe and the Poliosauridce of North America,
probably in many of the amphibia of both continents, and even in Edapho-
saurus of Saxony and Bohemia, Pennsylvania (?), and New Mexico. It is
not probable that free communication across the North Atlantic continent
was interrupted at the time the Pittsburgh shale was laid down, and the
genus Edaphosaurus, or its immediate ancestor, was probably already in
existence and had spread east and west.

Shortly after this stage the free passage across the North Atlantic conti-
nent was interrupted either by an arm of the sea (the southern extension of
the Davis Strait) or by the elevation of the Hercynian chain on the North
Atlantic continent. This isolated a fauna in North America which, devel-
oping by itself, resulted in the assemblages fomid in the Texas, Oklahoma,
Kansas, Illinois, and Prince Edward Island beds.

For the third possible connection we have no evidence from vertebrate
fossils. It is suggested by White '^ that the fern Gigantopteris may have
reached North America by this route.

THE FATE OF THE AMERICAN FAUNA.

The North American fauna developed per se, and apparently disappeared
before the beginning of the Triassic. It is very evident why some forms
should have so disappeared, for they had reached a degree of specialization

" Willis, U. S. Geological Survey, Professional Paper 71, p. 345.
i* Willis, ibid., p. 425. (Report of Sapper's work.)
" Koken, Festband d. Neues Jahrb. fur G. M. u P., 1907, Tafel xix.
"" White, David, Proc. U. S. Nat'l Mus., vol. 41, p. 511 el seq., 1912.

156 THE PERMO-CARBONIFEROUS RED BEDS OF

which could not endure even a sHght change of environment. What the
change was it is difficult to say. The Red Bed conditions were apparently
continued unchanged into the Triassic. On Pdleo Creek, in Rio Arriba
County, New Mexico, the author secured a section of a bluff 800 feet high.''
The lower 400 feet or so carried Permo-Carboniferous vertebrates, the upper
100 feet Triassic vertebrates; the intervening beds were barren, but with
absolutely no indication of a change in the nature of sedimentation or climate.
Only at the top of the bluff, above the lowest Triassic fossils, was there a
difference in the color and character of the beds. This is typical of the condi-
tions over most of North America. In some places, as in western Texas,
there is a general difference in the structure, beds, color, and character of the
clays and sands, but no great unconformity or evidence of pronounced change.
What caused the extinction or displacement of the fauna we can not say —
perhaps some slight climatic change, or change in surface, elevation, humid-
ity, or food-supply. Any of these would have been sufficient.

That the North American fauna, or close relatives of some of its members,
existed in Europe, in a somewhat modified form, after it had become extinct
in the western hemisphere there can be no doubt. This relation between the
faunas is, however, a question too large for discussion in this paper.

* Williston and Case, Jour. Geol., vol. .\.\, pp. 1-12, 1912; Carnegie Inst. Wash. Pub. 181, p. i, 1913.

APPENDIX.

THE BRIER CREEK BONE-BED AND ITS FAUNA.

By E. C. Case.

In the summer of 1912 the author discovered this large bone-bed on the
ranch of Mr. Estell, about 12 miles south of Dundee, a little east of the road
between Dundee and Archer City, in Archer County, Tex. The next summer,
with the help of Mr. W. I. Robinson, a graduate student in the University
of Michigan, the bed was excavated as far as time permitted (plate 21).

The bones occur in a light gray clay near the top of the Wichita forma-
tion. As has been previously shown by the author, the road running south
from Dundee, in Archer County, Texas, marks approximately the first out-
crop of the limestones which are regarded as the lower deposits of the Clear
Fork formation. The bones were practically all isolated, but one or two par-
tially complete skeletons being found, and almost all of the skull material con-
sisted of separate bones. It is evident that the pool or swamp in which the
bones were collected was more or less of a macerating tank in which the skele-
tons went to pieces and were disturbed by movements of the slimy mud and
by the action of animals which trampled the decomposing bodies as they fed
upon them or in their struggles to escape when mired. Toward one end of
the bed the lowermost bones rested upon a layer of coarse gravel, indicating
that a current may have swept the cadavers into the pool. As the bones are
in many cases badly fractured and show signs of decay, but are never water-
worn, it is probable that the bones themselves were not disturbed by currents
after the bodies were macerated. Unfortunately the layer which contains
the buUc of the bones was invaded, either before or after the solidification of
the mud, by waters rich in iron, which destroyed the surface of the bones and
at the same time cemented them into a hard mass from which they can not
be recovered. Both above and below this layer there was an abundance of
material in splendid condition, but if it had not been for the accident of the
iron-bearing water invading the deposit the bones recovered would have been
numbered by thousands instead of hundreds.

One of the first specimens discovered was the nearly complete skeleton of
an Edaphosaurus cruciger Cope, consisting of the vertebral column to the base
of the tail, most of the limb bones, the pelvic and pectoral girdles, and an imper-
fect skull. This gave hopes that other associated skeletons would be found, a
hope that was, unfortunately, not realized. There have been identified:

Dimetrodon incisivus Cope. Cricolus heteroditus Cope.

Dintdrodon sp., small form. Diplocaulus sp.

Theropleura sp. Trimerorhachis (?) sp.

Clepsydrops natalis Cope. Dorsal plate of a member of the Dissorhophidae.

Diadectes sp. Dermal scutes of an amphibian.

Diadecles maximus Case. Numerous bones of amphibians and reptiles, many

Bolosaurus slriatus Cope. belonging to new forms, but some undoubtedly

Poliosaurus sp. belonging to known forms described from incom-

Archeria robinsoni genus ct sp. nov. plete material.

Eryops megacephaltis Cope.

157

158 THE PERMO-CARBONIFEROUS RED BEDS OF

The only forms listed as new are those indicated by bones which can not
be, by any possibility, referred to forms already known. Certain new humeri,
femora, scapulas, and so forth, are provisionally referred to Cricotus, Tliero-
pleura, and others, as seems most probable.

The most abundant genera in the bed are Edaphosaiinis and Cricotus,
next comes a small form of Dimctrodou, with a good many bones of the larger
Dimetrodon incisivus, and some bones which appear to belong to Dinietrodon
gigas. The Cotylosauria are represented by a single imperfect vertebra of a
Diadectes of medium size and a single humerus of a large Diadectes, probably
D. maxiniits. This is very striking, as in the same region and at almost the
same horizon the bones of Diadectes are very common. Several jaws and some
limb bones and vertebrae of Bolosciiirns occurred scattered through the bed.

The probably aquatic Cricotus occurs in abundance, with fairly numerous
remains of Eryops, but it is singular that very few recognizable bones of the
smaller amphibians were found. Zatracliys and TrinicrorhacJiis are among
the more common forms in the Wichita fonnation. The intercentra of these
forms are generally very abundant, but in the Brier Creek bed only a single
intercentrum and perhaps a humerus were found among the hundreds of
specimens taken. The occurrence of Diplocaidiis is one of the most interest-
ing though not unexpected things. This genus occurs in the Illinois beds,
certainly at a lower horizon, but previous to the excavation of this bed none
had been found in the Wichita formation.

There is a total absence of any remains of fish. Sharks would undoubtedly
have been attracted by the cadavers if there had been access to the pool
from the open water, and the presence of dipnoan and crossopterygian fishes
woidd certainly have been expected. The absence of these forms leads to the
suggestion that the place of deposit was a stagnant pool or perhaps a spring
or seep with an area of deep muck around it, in which the animals became
mired. Such an assumption throws some doubt upon the aquatic character
of Cricotus, which is so strongly indicated by the structure of its skeleton.

Aside from the light thrown upon the structure of old forms, the number
of new things which have come to light in the bone-bed is of great interest.
It is always to be expected that something new will be discovered in such
large accumulations, but the very considerable number of new things is
rather surprising. Unfortunately the new forms are represented by single
bones or by separate bones which can not be associated with certainty; for
this reason the author has not given new names to all, for there remains the
possibility that some of the bones regarded as indicating new forms may
belong to genera already described from fragmentary material.

CRICOTUS.

This genus is represented in the collection by abundant material of both
large and small individuals. The author has previously "• suggested that but

» Carnegie Inst. Wash. Pub. 146, p. 78.

NORTH AMERICA AND THEIR VERTEBRATE FAUNA.

159

two species of this genus can be determined from described material and is
now inclined to be in doubt whether even this distinction can be made,
though there can be little doubt that more than one species was present in
the fauna. The species Jiypantricus was established by Cope upon the pres-
ence of small spout-like processes extending forward from the anterior edges
of the neural canal. In the collection from Brier Creek vertebrse otherwise
indistinguishable may be separated by the presence or absence of the process,
but it is far from clear whether these are lost in some cases by accident, or
may be present in one part of the column and absent in another.

Skull (fig. 32). — In common with most of the specimens recovered, the
bones of the skull were macerated apart in most cases. The tops of two skulls
were found together, and in one. No. 3001," the sutures can be clearly made
out and establish the position and shape of the bones as described by Case
and Broom.

Fig. 32. — Cricotus heteroclitus Cope. X -3. No. 3001. Upper surface of skull, showing sutures, /.frontal;

p, parietal; pif, postf rental; pto, postorbital; sq, squamosal; lb, tabulare; so, supraoccipital.
Fig. 33. — Cricotus sp. X 'A- No. 3029. Outline of inner surface of large jaw.
Fig. 34. — Cricotus sp. X ^3. No. 3418. Fragment of a jaw, showing form of teeth.

One large jaw (fig. 33) nearly 300 mm. long is nearly complete, lacking
only the articular region. Unfortunately it was covered by a most refractory
matrix, which makes it impossible to work out the .sutures. The jaw. No.
3029, is very high posteriorly, with a strong coronoid region, but becomes
very slender anteriorly. On the inner surface the posterior Mcckaelian
opening is very large; anterior to this there is a single, smaller opening.
The walls of the jaw, stirrounding the Meckaelian cavity, are relatively
thin, permitting a large amount of fracturing. So far as can be made out,
the splenial enters into the symphysis and forms the lower part of the
anterior end of the jaw and the inner wall of the dental groove, at least
in the anterior half of the jaw. In the anterior half of a small jaw, No.
3045, the outline of the bone is clearly shown. Near the middle of the dental
series of the large jaw there is a small patch of teeth on the inner wall of the

" In this article all numbers given, unless otherwise stated, refer to the collection of the University of
Michigan.

l6o THE PERMO-CARBONIFEROUS RED BEDS OF

dental groove, possibly on the anterior end of the coronoid, but the outline
of this bone can not be made out. The outer surface of the jaw is sharply
reticulate. The sutures of the posterior end of the jaw can not be made out,
but the general form is shown in figure 33. The most surprising thing about
the jaw of Cricotus is the small size of the teeth and their peculiar form; 40
teeth of small size can be counted in the large jaw and there is no indication
in this jaw, nor in any of the fragmentary ones recovered, of larger teeth at
the anterior end. The teeth are long and slender, with broad bases fused to
the edge of the dentary, but rapidly contracting to a cylindrical form. The
apex is chisel-shaped, with the cutting-edge running fore and aft and the
whole edge slightly moved. to the rear, so that the posterior edge overhangs
the posterior edge of the body of the tooth (fig. 34). The dental series occu-
pies a deep groove formed by the dentary and the splenial and coronoid (?).

Vertebrae. — Of the numerous vertebra fotmd only two, intercentra and
centra, were fomid in position; these are from the caudal series. The inter-
centra are fully as thick as the centra and very similar to them in appearance.
The neural arches are anchylosed to the intercentra, at least to the elements
which bear the chevron bones. In the figures published previously by Cope
and Case the netiral arch is shown directly above the chevron-bearing ele-
ment and apparently supported by it; this is as the vertebra; appear in the
specimens in the American Museum in New York; in the vertebrae in this
collection the neural arches are in sutural connection with the elements bear-
ing the chevrons and there can no longer remain any doubt of their position.
The same condition is found in other stegocephalians.

It has been generally thought that the intercentra of the dorsal region
were much thinner than the centra; thin disks regarded as intercentra are
not uncommon in most collections from Texas, but few have been found in
position. In the American Museum collection there is a sacral series with
a thin disk directly posterior to the last sacral centrum (fig. 51 e, Publication
No. 146, Carnegie Institution of Washington), but without chevron or neural
arch. Abundant thin disks with and without chevrons occur in all collections
from Texas. The author is of the opinion that the thin disks without processes
are pygal intercentra and that immediately following them in the anterior
caudal region there are thin intercentra which bear chevrons. The tail was
proportionately very long and strong and both the intercentra and the centra
became elongated in the middle of the series, something after the manner
of the mid-caudal vertebras of the Eocene cetacean Basilosaurns. In this
mid-caudal region the intercentra became as long as the centra and came to
bear the neural arches as well as the chevrons.

Other thin disks with short diapophyses are believed to belong in the
cervical series.

From the fact that the thin disks can be located with considerable cer-
tainty in the cervical and caudal series, and that they are in the minority in
all collections, the author is inclined to the belief that the dorsal intercentra

NORTH AMERICA AND THEIR VERTEBRATE FAUNA. l6l

were as thick as the centra and resembled them very strongly. There are a
large number of separate disks without neural arches, which are indistinguish-
able otherwise from the arch-bearing centra. They have a strong scar upon
the upper surface, to all appearances identical with the scar which would
appear upon the upper surface of the centra if the arch were removed. The
presence of the scar is explained by the fact that the anterior edge of the
neural arch extends far anterior to the edge of the centrum and in many of
the vertebras fits accurately into the scar mentioned. The original statement
by Cope that the neural arches were not anchylosed to the centra is erro-
neous, as already shown by Case, and in the present collection there is no
evidence that the arches were loosely attached, nor was a single separate
neural arch collected.

A most striking feature in several of the vertebrce is the presence of a
distinct canal, running lengthwise through the neural arch above the neural
canal. This is clearly shown in at least five vertebras, where it has been
worked out, and is indicated in several others, where it is occluded by the
compression of the specimen. In one vertebra, apparently an anterior dorsal,
the canal — supraneural canal as it may be called — is higher than wide and
separated from the neural canal by a considerable thickness of bone. The
upper part of the arch is broken away, so that the exact dimensions of the
opening can not be given (plate 22, fig. i). Two other vertebrse from appar-
ently farther back in the series show similar canals. In one with the spine
complete the canal is more nearly circular and the partition between it and
the lower canal is very thin and has been in part destroyed by decay. In
one of the larger anterior dorsals the canal is complete, but its upper two-
thirds appears to be divided vertically by a narrow partition.

The supraneural canal seems to be most perfect in the vertebra with
prominent transverse processes, regarded as anterior dorsals. Here it is
narrow, but of considerable vertical extent, and is either complete or inter-
rupted in a part of its aperture by a vertical partition. In the vertebrEe with
short transverse processes (anterior dorsals ?) , the canal is small and circular,
or the neural arch is imperforate but marked by very deep pits extending
inwards in the position of the canal. In the sacrals deep pits are present,
but the arch is imperforate. It is probable that this canal lodged a strong
ligament which was in some parts of the column continuous and in others
present in segments between the vertebra.

Pelvis. — There are two perfect and two imperfect ilia which are provision-
ally assigned to the genus Cricotiis. They difter from any known form of ilia
from the Texas beds in possessing a long, thin process which starts from the
middle of the posterior side of the crest and extends obliquely backward and
upward. The sides of the process are flat and nearly parallel and the narrow
terminal face evidently bore a cartilaginous extension. The lower portion of
the bone is rather long proportionately and the cotylus is shallow. The articu-
lar faces for the pubis and ischium are rather thick (plate 22, figs. 2 and 3).

[62

THE PERMO-CARBONIFEROUS RED BEDS OF

The pubis (fig. 35) assigned to Cricotiis has the inner side of the blade
shghtly concave. The anterior end of the inner or lower edge is thin anteri-
orly, but the posterior half is much thickened and there is a flat articular face
for union with the bone of the opposite side. When the two bones were in
position there was a large and rather deep notch at the anterior end of the
pelvis. At the posterior end of the thickened portion there is a small, flat area
running up to the foramen and looking obliquely backward and inward,
probably for attachment with the ischium. The pubic foramen is near the
posterior end and, as in the reptilian genus Vara-
nosaurus, is incomplete behind. On the inner side
of the upper edge, just above the anterior end of
the foramen, or a little more forward, is a small,
knob-like tuberosity.

The ischium. — There are several ischia in the col-
lection of the general form common in the smaller
Pelycosaurs. As this type is very abundant in the
collection it may be that it belongs to Cricotus.

Hunierits (plate 22, figs. 4 and 5, and fig. 36,
a and b). — There are four humeri of a new type,
which are referred to the genus Cricotus. Three of
these (No. 3419) are in excellent condition. They are pecuHar in their ex-
treme thinness and breadth. The articular surfaces of the ends are more
nearly parallel than is common in this bone in the Permo-Carboniferous
fauna. The proximal articular surface winds around the end of the bone and

Fig. 35. — Cricotus sp.
3247. Pubis of
a, outer face; h,
c, inner edge.

X -i. No.
right side,
inner face;

Fig. 36. — Cricotus sp. X 73-
(n) Articular face of proximal end, [h) articular face of distal end of humeras, No.

3419. (Same bone as shown in plate 22, figs. 4 and 5.)
(c) Lower face, (d) upper face, (e) articular face of proximal end, (/) articular face

of distal end of humerus of an immature individual. No. 3420.
(g) Distal end, (h) proximal end of femur, No. 3366. (Outline of articular faces of

bone shown in plate 22, fig. 6.)

descends upon the deltoid process. There is little or no widening of the end
to form a head, and the deltoid process is but an extension of the outer edge
of the bone, standing out at a low angle with the anterior face. The shaft is
very thin and wide. From the center of the articular face on the deltoid
process a sharp ridge passes downward and becomes the very thin outer edge
of the bone; this knife-edge continues to the distal end of the bone, where it
terminates in a small facet, evidently for cartilaginous attachment. The

NORTH AMERICA AND THEIR VERTEBRATE FAUNA. 163

deltoid crest almost disappears distally, but there is traceable a low, rounded
ridge extending obliquely across the anterior (upper) face of the bone to the
outer side of the distal end. A similar low, broad ridge rises from the dorsal
side of the inner edge of the proximal end and extends obliquely across the
shaft to the distal end, where it becomes stronger and forms the posterior
prominence of the widened face of the distal articular surface. The inner
edge of the bone is thin, btit not so sharp as the outer edge; it is short and
sharply turned outward on the large entepicondylar process. There is no
entepicondylar foramen, but there is a small ectepicondylar process. The
distal articular surface is rather narrow ; the radial condyle is very low and
almost entirely on the anterior face of the bone.

This humerus resembles very closely the one figured by Williston as a
new genus, but not named, from the Craddock bone-bed (Bull. Geol. Soc.
Amer., vol. 21, pi. 15, figs. 10 and lb), but differs in its proportionately greater
breadth, stronger deltoid process, proportionately higher entepicondyle, less
rounded radial condyle, and the presence of a distinct ectepicondylar process.
Length of figured specimen, 91 mm.

There are in the collection three much smaller humeri (No. 3420, fig.
36 c-f) very similar in form to the one just described, but with all the char-
acters less emphasized. These are probably from immature individuals of
the Cricotus.

Femur. — The femur (Nos. 3366 and 3363, plate 22, figs. 6 and 7, and fig.
36, g, h) associated with bones of Cricotus is of a very simple type. The
proximal end agrees very closely with the portion preserved in the New
York specimen. The proximal articular face is semicircular and nearly flat,
except where it descends upon the process of the inner side. This process is
not distinct from the bone, being simply a more acute portion of the edge.
The bicipital fossa is relatively shallow. The outer edge of the bone becomes
very sharp just at the lower edge of the fossa and is continued as a sharp
ridge directly down the outer side of the bone to the lower end, where it
terminates upon the outer condyle. The section of the shaft is semicircular,
with the outer edge much sharper than the inner. The distal face is con-
fined to the end of the bone, looking almost directly distal. The face is
divided by a deep groove on the posterior face, but the two halves are con-
nected by a broad isthmus. An average specimen is 75 mm. long.

Scapula (fig. 37, a, b, c). — Three imperfect scapuL-e are of a form and size
which suggest that they may belong with this genus. Only the scapula is pre-
served, no trace of coracoids being found (Nos. 3421 and 3422). The blade is
short and curved, with a broad distal termination. The proximal end is dis-
proportionately widened and there is a very large cotylus. The supraglenoid
foramen is exceptionally large and pierces the supraglenoid fossa directly, as
in the Cotylosaurs and OpJiiacodon; it is far larger proportionally than in any
known form from the Texas beds. The supracoracoid foramen is also very
large; it opens anterior to the supraglenoid tuberosity and above the cotylus.

164

THE PERMO-CARBONIFEROUS RED BEDS OF

Posteriorly both foramina open into the subscapular fossa, which has the
crescentic outline characteristic of the Amphibia. There is a small and very
sharp pit on the outer face of one specimen just beneath the cotylus, but
this does not penetrate the bone and is probably adventitious. There are
strong articular faces for the coracoid elements, and it is evident that these
were suturally connected with the scapula during life. The anterior border
is incomplete in all the specimens, but it was apparently rounded. The
short and broad scapula is but another bit of evidence that Cricotiis was
aquatic — if this scapula belongs to that genus.

An ulna, radius, tibia, and fibula are here described as possibly belonging
to the genus Cricotiis, though the association is based upon little more than
the appropriate size. They may very possibly belong to some other form.

The itUia (No. 3423, fig. 37, //) has a large and well-developed cavity for
the condyle of the humerus confined entirely to the anterior face of the proxi-

FiG. 37. — (a) Outer face, (i) posterior edge, (c) inner face of scapula of right side of Cricotus sp. ;
ISIo. 3422. X 73.
(d) Radius, No. 3424; (e) tibia, No. 3425; (/) proximal face of tibia, (g) fibula, No.^ 3426;
(ft) ulna. No. 3423. Lower limb bones provisionally referred to Cricotus (?) sp. X "i-

mal end. The inner face of the bone is nearly flat. The whole bone is slightly
convex outward, with a suggestion of a sigmoid curve due to the expansion
of the outer side of the proximal end and the rather sharp incurvature of the
distal end. The distal face shows no division into facets and does not lie in
the same plane as the proximal end ; a slight twist of the shaft turns the outer
edge of the face slightly. The section of the shaft is oval -triangular, with
the greatest thickness at the anterior edge. Length 55.5 mm.

The radius (fig. 37, d) is very simple. The shaft is somewhat flattened
and the articular ends are oval. On one side of the lower end the shaft is
flattened and the edge very thin and somewhat expanded. Length 44 mm.

The tibia (fig. 37, c and/) is rather slender, with the proximal end slightly
enlarged and the face nearly triangular. Length 44 mm.

The fibula (fig. 37, g) has an oval proximal face, the shaft is flattened, and
the distal end is much widened and divided obscurely into two facets. The
inner facet looks obliquely inward and downward and the outer facet looks
directly downward. Length 52 mm.

Any or all of these bones may belong with the reptilian humerus No. 3354
(plate 24, fig. i).

NORTH AMERICA AND THEIR VERTEBRATE FAUNA.

i6s

ERYOPS.

Although so much has been written about this genus the collection
permits a few new points to be added.

The interdavicle and clavicle have been known from almost the first dis-
covery of the genus, but have been found preserved in such refractory matrix
that the exact character of the sculpture has not been clearly seen. The
specimens from the Brier Creek bone-bed are so well preserved and naturally
cleaned that this character is beautifully shown. The interclavicle (plate 23,
fig. i) is slightly imperfect, having lost some of the slender processes on the
anterior and posterior borders, but it is apparent that very little can be
missing. The posterior end of the clavicle (plate 23, fig. 2) is greatly fore-
shortened in the photograph ; the small patch of very coarse sculpture marks
the position of a sharp bend in the bone.

The cleithrum (plate 23, figs. 3 and 4) has been known to exist, but no per-
fect specimen has previously been recovered. It is gently sigmoid in outline,
with the anterior two-thirds drawn out into a slender process nearly circular
in section. The distal end of this process is marked by strong, linear rugosities.
The posterior third is expanded into a scimitar-shaped blade, very thin on the
convex edge but thick at the point of union with the slender process. The thin
edges show some radial striations. The inner side of this portion is excavated
by a deep linear cavity, into which fitted the upper edge* of the scapula.

Humerus. — A small humerus (No. 33 16, fig. j,S,a,b,c) is very probably that
of an immature Eryops. The articular faces are deeply concave, as if there

Fig. 38. — (a) Anterior face, (i) posterior face, (c) outer edge of right humerus of an immature individual,
Eryops megacephalus Cope, No. 3316. X /j.
{d) Lower face, (e) upper face, (/) proximal face, (g) distal face of femur of an immature individual, prob-
ably Eryops{}), No. 3432. X ^3. (The original is broken and the figures {d) and (e) are somewhat
restored.)

had been a large mass of cartilage attached. In general the form is that of
an Eryops htimerus, but the bone is proportionately shorter and heavier. The
ectepicondylar process is not separate from the distal articular face, and the
process on the dorsal surface of the inner edge of the proximal end is quite

i66

THE PERMO-CARBONIFEROUS RED BEDS OF

small. The bone resembles in many respects the one figured by Williston
(BuU.Geol. Soc.Amer.,vol. 21, pi. 15, figs. 4 a, Z>, r), but differs in the presence
of the process on the dorsal surface of the inner edge of the proximal end. The
articular faces, also, do not correspond with the figttres given by Williston.
Nevertheless I am inclined to think that the bones are the same and that the
process mentioned has been lost in Williston's specimen.

Femur. — No. 3432 (fig. 3<S, d-g) is a small and rather heavy femur which is
evidently that of an amphibian but is not referable to any known form, unless
it belong to an immature Eryops. There is a deep bicipital fossa and a very
strong prominence on the inner edge near the middle of the shaft. The prox-
imal articular face is crescentic in outline, flat, and confined to the end entirely.
The distal face is wide transversely and narrow antero-posteriorly ; the tibial
and fibular faces are undivided. If this is the femur of an immature Eryops
there must have been very considerable changes in the proportions of the
bone during development. The ridge on the anterior face woiild have to
become more prominent and the bone more elongate and slender. The speci-
men has been broken and crushed so that it is a little difficult to restore it
exactly, but an attempt has been made in the figure.

UNASSIGNED FORMS, AMPHIBIA.

There are three femora which are regarded as amphibian. It is noticeable
in the collection that the femora can be divided into two groups, one in
which the adductor ridge on the pos-
terior face crosses the shaft obliquely
and one in which the ridge is confined
to the inner edge and passes directly
downward to the distal end of the
bone. Those in which the ridge is
oblique arc regarded as reptilian and
those with the ridge confined to one
side as amphibian. This seems to be
the most common arrangement in the
two groups, though in Opliiacodon the
ridge is confined to one side of the
bone.

The first femur (No. 3298, fig. 39, fl,
b, c) is regarded as probably amphibian

hpppiic;p nf thp nnqitinn nf thp iddnrtnr ^^^- 39-— (a) Inner edge, {b) lower face, (c) upper

Decause oi tne position oi tne aaaucior j^^^ ^^ ^^^^^ ^^ j.jg,^j <,yg ^f unnamed amphib-
ridge, although its general form is that ian (?), No. 3298. x -j- ,„,.,,, ,

° ° ° . (d) Lower face, (c) proximal face, (/) distal face of

of a reptile. The shaft is very long and femur of right side of unnamed amphibian, No.

slender and the ridge is very thin and

prominent. In this respect it resembles the femur from the Craddock bone-
bed figure by Williston (Amcr. Perm. Vert., pi. xxxii, fig. 4), but differs
decidedly in the well-formed and very reptilian looking proximal and distal

NORTH AMERICA AND THEIR VERTEBRATE FAUNA.

167

articular surfaces. The proximal end has a deep bicipital fossa, but lacks
any distinct process on the inner side, its place being taken by the upper
end of the ridge, v/hich is here sHghtly thickened. The distal face is very
similar to that of a Pelycosaurian reptile, being sharply divided into two
faces by a deep groove on the anterior face. This bone may very possibly
turn out to belong to a reptile when the skeleton is known.

The second femur (No. 3431, fig. 39, (/, c,f) is similar to the one from the
Craddock bone-bed figured by Williston (Amer. Perm. Vert., pi. xxxiii, fig. 4)
and by him referred to Broil icU us {A spidosa urns) pellatiis. It is devoid of well-
marked articular condyles but has a prominent adductor ridge. It is prob-
ably to be associated with the single dorsal plate discovered (No. 3404),
described below. Length 53.5 mm.

The third femur (No. 3295) (plate 23, figs. 5 and 6, and fig. 40, a and b) is
also typically amphibian and might be regarded at first as that of a young
Eryops, as the articular ends are deeply excavated, indicating the presence of
considerable cartilage, but closer study reveals essential differences. The ad-
ductor ridge is relatively much higher and thinner than in the adult Eryops.

Fig. 40. — (a) Proximal face, (b) distal face of unnamed amphibian, No. 3295. X 73. (Articular
faces of bone shown in plate 23, figs. 5 and 6.)
(c), (rf), {e) Three views of tibia or radius of an unnamed amphibian, No. 3299. X 73.
(/) Outer face, (g) anterior edge of ilium of left side of unnamed ampliibian, No. 3430. X 73.

In the adult of that genus there is a very deep bicipital fossa and its edges meet
below in a strong, almost rugose, prominence at about the middle of the shaft;
below this the ridge is very thick, with a flat terminal face, and is continued to
the distal end of the bone. In the new form the tibial side of the bicipital fossa
is a strong ridge which develops at the upper third of the bone into a strong,
circular, and rugose tuberosity with a depressed face; below the tuberosity
the ridge is very thin, almost a knife-edge, and it terminates a considerable
distance above the distal condyles. The articular faces are proportionately
larger than in the adult Eryops. Length 98 mm.

A bone, No. 3299, is probably amphibian and is either a tibia or a radius.
The form is best understood from figure 40, c, d, e. Length, 56 mm.

A small ilium, No. 3430 (fig. 40,/ and g), resembles in many ways that of
Eryops and may be that of an immature individual of the genus. There are,
however, some important differences. The crest is vertical like that of Eryops,

l68 THE PERMO-CARBONIFEROUS RED BEDS OF

but the posterior edge does not overhang the ischial border, forming a deep
notch. The anterior edge of the lower end of the ilium is thickened, but not
after the manner of Eryops. In that genus there is a sharp ridge on the inner
edge of the bone and the outer edge is concave, but in this specimen the whole
bone is convex from without inward. The cotylus is relatively higher than
in Eryops.

A neural spine (plate 22, figs. 8 and 9), with the arch and transverse proc-
ess, and the apex of a second spine, No. 3294, indicate the presence of an as
yet undescribed amphibian, probably in the line of Zatrachys or Aspidosaiinis.

The neural arch is typically that of a temnospondylus form with well-
developed zygapophj^ses and transverse processes. The spine is relatively
very high, ftiUy as high as that of an Eryops vertebra of three or four times
its size. It belongs to a distinctively high-spined amphibian and is the first
indication of such a form in the Texas beds. The only other form with high
spines which has been regarded as showing amphibian characters is Platy-
histrix, from the New Mexican beds, and this probably is a reptile. The
exact position of the form can not be stated ; it probably belongs to the as yet
poorly understood line in which occur Zatrachys, Aspidosauriis, and Dissoro-
phus. It is noteworthy that but a single intercentrum of a temnospondylus
amphibian of small size was found in the large amovmt of material taken
from the bed; this may be due to accidents in accmnulations of the material,
but if so it is very peculiar. I would rather attribute it to the pccttliar asso-
ciation of animals in the bed. However, many small forms of amphibians
were found which are in all probability temnospondykis, and the peculiarity
must await future explanation.

The upper end of the spine is flattened from side to side and is somewhat
spatulate in form. The deep reticulate rugosities cover the upper end and
extend down upon the sides to a point a little below the middle of the spine,
becoming narrower below and terminating in a blunt point. The anterior
and posterior edges of the spine and the spaces below the rugosities are
smooth. The second specimen, the apex of a spine, is expanded after the
manner of Zatrachys apicalis and is rugose on the top only.

Length from base of the transverse process to the top of the spine 86.5 mm.

No. 3404 (fig. 41 , a and b) is a single dorsal plate from the apex of a spine of
a small amphibian. This resembles the plates from the dorsal region of Cacops
aspidephorous Williston, in general form, but was free from the spine, as in the
Dissorophidce. Aspidosaurus has been reported from the Clear Fork beds as
low as just west of the Dundee-Archer City road, i.e., the lowest part, but this
is the first specimen of the small armored amphibians from the Wichita forma-
tion. The upper surface is deeply rugose, with relatively large pits ; one edge,
the anterior (?), is free from pits for a short distance, but is marked with fine
lines, evidently marking the position of an overlap by the preceding plate.
The lower surface shows very slight projections in the middle portion, as if
the plate were loosely attached by cartilage to the apex of the spine below.

NORTH AMERICA AND THEIR VERTEBRATE FAUNA.

169

UNASSIGNED FORMS, REPTILIA.

A femur, No. 3363 (plate 24, fig. 5, fig. 42, a and b), is rather short and
heavy, but not radically different from some known forms. The proximal
articular face is rather narrow, slightly thicker at the inner side, and confined
entirely to the end, except where it descends a little upon the inner edge. The
process is sharply set off from the inner edge and terminates well below the end
of the bone in a flat, oval face looking nearly straight upward. From the base
of the process a sharp adductor ridge runs oblicjuely across the lower face of
the bone to the opposite of the distal end. Aside from this ridge the shaft is
nearly circular in section. The lower end is expanded and the articular face
has a continuous articular area; the inner part is the broader and is partly
cut off from the outer by a deep groove on the anterior face of the bone. This
part of the articular face looks obliquely inward and backward. The outer
part is narrow antero-posteriorly and looks obliquely outward and backward.
This bone resembles in many respects the bone figured by Case (Publication
55, Carnegie Institution of Washington, plate 5, fig. 7) as the femur of Clepsy-
drops and by Williston (American Permian Vertebrates, plate 24, figs. 5, 6, 7)

X ?3. No. 3404. Dorsal plate.

44 ^^

a, upper face; b, an-

FiG. 41. — Unnamed amphibian.

terior edge.
Fig. 42. — Unnamed reptile. X %■ No. 3363. Articular face.s of femur shown in plate 24,

fig. 5. a, distal face; b, proximal face.
Fig. 43. — Unnamed reptile. X Jj. No. 3354. Articidar faces of humerus shown in figures

I and 4, plate 24. a, proximal face; b, distal face. The faces are arranged in their

natural position.
Fig. 44. — Archeria robinsoni. X /3. No. 3246. Articular faces of the humerus shown in

plate 23, figs. 7 and 8. a, proximal face; b, distal face.

as the femur of Captorhinus illinoisensis. There is much doubt that it is the
femur of a true captorhinid, as that group does not occur in the Wichita
formation nor in the Illinois beds. The vertebrae of the captorhinids are so
characteristic and bones from the vertebral column are so much more abun-
dant than from other parts of the skeleton that they could scarcely fail to
be recognized if present. The femur is tentatively associated with the
humerus described below (No. 3354).

There are two types of humeri which are different from forms previously
described. The first type, No. 3354 (plate 24, figs, i to 4, fig. 43, a and b), is
represented by six good specimens of different size. The group forms a series,
the extremities of which might be regarded as belonging to diff'erent species,

lyo

THE PERMO-CARBONIFEROUS RED BEDS OF

but taken as a whole seem certainly to belong together. The largest specimen,
evidently from an adult form, resembles most remarkably the humerus of
Ophiacodoii minis Marsh (fig. 31 A, PubUcation 181, Carnegie Institution of
Washington ; fig. 5, plate 35, Amer. Perm. Vertebrates) . The differences noted
between this bone and the humerus of Ophiacodon are: In Ophiacodoii the
distal and proximal ends are "relatively little divergent"; in this form they
are at right angles. The ectepicondylar process in Oph iacodon extends dorsally
at nearly a right angle; in this form it extends dorsally and outwards at an angle
of 45°. The radial condyle of Ophiacodon is nearly circular and looks largely
forward; in this form it is smaller and looks more distally than forward.

Table 4. — Proportional Measurements of Specimens.

Yale Chicago
specimen ' specimen
of ! of
Ophiacodon \Ophiacodon

University

of
Michigan
specimen

Length

mm.

72.8

mm.

lOI

mm.
85
47-4

Breadth distal end ....

34-6

In the smaller specimens the ectcpicondyle is less prominent and the
articular faces are less well formed and distinct, as would be expected. The
proximal articular face is continued ovit vipon the deltoid process, but in the
larger bones this connection is broken by the connecting ridge becoming
thinner until the face upon it disappears. The entepicondylar foramen is
nearer the lower end.

The second type of humerus is so radically different from any form as
yet discovered in the Texas beds that it is certainly new and may be called
Archeria robiiisoiii. The whole bone (plate 23, figs. 7 and 8, fig. 44, a and b),
represented by one complete and two incomplete specimens (No. 3246), is very
thin and broad, resembling in this character the form assigned to Cricotns, but
differs from it very largely in other particulars. The articular surface of the
proximal end is confined to the inner half of the extremity and has the oblique
position common to the Pelycosaurs. The deltoid process is well down on the
anterior side and has a large facet deeply sunk in the end of the process. The
outer edge of the bone is thin, terminating in a knife-edge ; it originates from
the back of the deltoid process and curves sharply backward at first; turning,
it runs straight down to the distal extremity, becoming slightly thicker at the
distal end. The inner edge runs slightly inward for its proximal one-third or
more and then bends sharply outward on the entepicondylar process at nearly
a right angle to its former coiurse. This edge is thin, but not sharp, as is the
outer edge. The entepicondylar process is large, being approached in this
regard, so far as I know, only by Casea and the Diadectid reptiles. The entepi-
condylar foramen perforates the bone just at the point of jvmction of the
process with the shaft. The inner edge of the process has a very narrow face,
with evidence of the attachment of a cartilaginous extension.

NORTH AMERICA AND THEIR VERTEBRATE FAUNA.

171

On the posterior face of the bone a ridge starts just above the opening
of the foramen and runs obhquely across the bone; becoming sharper and
higher toward its distal end, it tei-minates free from the articular face. The
distal articular face is confined entirely to the end of the bone. The face for
the ulna is slightly oblique, winding around the end of the bone; the radial
condyle is hardly distinguishable.

Length of the bone, 87 mm. Width at upper edge of the entepicondylar
process, 49.5 mm. Height of the entepicondylar process, 44.5 mm.

Pelvis. — There are a number of ilia (No. 3428, fig. 45, a and b) more closely
resembling that of Varanosaurus than any other known form from the Texas
beds, but as Varanosaurus does not occur in the Wichita, these bones are
provisionally associated with Poliosaurus as the most likely form. A perfect
specimen of average size has an elongated narrow crest projecting almost
directly to the rear. The outer face of the crest is smooth, but on the inner
face there is a strong, sharp ridge standing out at right angles to the rest of
the bone. The anterior end of this ridge is the highest and it gradually
diminishes luitil it disappears upon the distal portion of the face. The ridge
is almost identical with that found in the same position in Varanosaurus and

Fig. 45. — (a) outer face, (6) inner face of ilium of right side of Poliosaurus (?), No. 3428.
X ?>

(d) inner face, (e) inner edge of pubis of right side of unnamed reptile, No. 3245. X %•

Pcecilospondylus and perhaps is to be regarded as indicating some relationship
between the forms mentioned from the upper and lower formations. The
similarity to Varanosaurus is also to be seen in the somewhat elongated
cotylus, with the face for the ischium longer than that for the pubis, the
two faces standing almost at right angles to each other. Length of an
average specimen, 58.5 mm.

It is possible that the pubes referred to Cricotus may belong with this
ilium and to Poliosaurus, for they strongly resemble the pubes of Varanosa iirus.

A small ilium, No. 3429 (fig. 45, c), is totally different from the preceding;
it may be that of an amphibian, but is more probably reptilian. The crest is
somewhat imperfect, being slightly broken at the posterior end. The cotylus
is relatively deep. The articular surfaces for the ptibis and ischium are deeply
hollowed out, showing the presence of a considerable quantity of cartilage and
the probable immaturity of the animal. The form is best appreciated from
the figiire.

172

THE PERMO-CARBONIFEROUS RED BEDS OF

Pubis. — The pubis No. 3245 (fig. 45, d and e), considered as reptilian,
resembles very closely that of Varanosaunis, having the same peculiar bend-
ing of the plate-like anterior portion, giving the floor of the opening a convex
surface, upward, both fore and aft, and from side to side. It differs from the
same bone in Varanosaurus in the position of the foramen, which is well within
the bone instead of being so near the posterior end that its posterior border
is ii:icomplete and is closed by the adjacent portion of the ischium. This
pubis probably belongs to Clepsydrops or Poliosaurus.

LOWER LIMB BONES.

There are certain bones of the lower limbs which are so heavy and short
that they can not be associated with any of the bones described above. It
is possible that they may belong with some of the amphibians or may
even be bones of immature individuals of Eryops, but they differ so widely
from the mature bones of the last genus that it seems more probable that
they belong to some form of diadectid reptile otherwise unindicated.

Fig. 46. — Unnamed reptile. X 72, ■
(o) (6) (c) ((f) four views of tibia, No. 3355; (e) tibia, No. 3433; (/) ulna, No. 3434.

Two tibiae, No. 3355 (fig. 46, a, b, c, d), are rather short and heavy, with
a poorly developed groove on the anterior face of the upper end. The proxi-
mal articular face is semicircular, with its long axis nearly at a right angle to
the long axis of the distal face. The shaft is angular, due to the development
of ridges, one extending from the inner edge of the proximal end to the corre-
sponding point on the distal end, another from the outer part of the anterior
edge of the proximal end to the outer part of the posterior edge of the distal
end. Length, 48 mm.

Three tibiae. No. 3433 (fig. 46, e), similar to the preceding but lacking
the strong twisting of the shaft which brings the two faces into such strong
angulation, also lacking the prominent ridges.

Two ulnae, No. 3434 (fig. 46, /) , which may belong to an immature Eryops.
These, of all the fore-limb bones, approach nearest to the amphibian type, but
can scarcely be assigned to the genus Eryops with certainty. The proximal
face is nearly circular and quite flat, but is strongly inclined forward. The
shaft narrows rapidly below the head and then expands slowly to the distal
end. The distal articular face is a narrow oval with a slight undulation of the
inner edge. Length, 61.5 mm.

NORTH AMERICA AND THEIR VERTEBRATE FAUNA.

173

Vertebrce. — It is most peculiar that in all the material there are practically
no reptilian vertebrae of the Cotylosauria ; a single imperfect vertebra of
Diadectes and a few Bolosanrus vertebra have been determined. The re-
mainder of the many hundred vertebrae found are Pelycosaurian. Aside
from numerous axis vertebras which may with certainty be referred to differ-
ent species of Dimetrodoii , large and small, there are two which belong to the
short-spined Pelycosaurs. The first, No. 3441 (fig. 47, a and b) , is represented
by a complete neural arch and by an imperfect arch with a half of the cen-
trum. The arch is relatively low and heavy, broader behind than in front,
and with a pit at the posterior end of the upper edge. The anterior end does
not project over the anterior edge of the vertebra, as in Dimetrodon. The
posterior edge is thickened and rounded above, but below terminates ii:i a
deep pit between the edges, which extend out upon the posterior zygapophy-
ses. The anterior zygapophyses are small and almost rudimentary ; the pos-
terior are fully formed. The transverse processes descend from the anterior
end of the arch. This is probably the arch of the axis of Theropleura.

Fig. 47. — Neural arch of axis.

a, from side, (b) posterior face, of Theropleura (?),
No. 3441. X ;>

c, from side, (d) posterior face, of unnamed rep-
tile, No. 3442. X %.

The second arch. No. 3442 (fig. 47, c), is similar to the one just described,
but is more slender. The spine is more expanded antero-posteriorly, so that
the edges overhang the lower edges of the arch. The posterior edge is thin,
and, instead of ending in the pit between the posterior zygopophyses, is con-
tinued as a sharp ridge on the bottom of the pit for some distance. At
present it is impossible to assign this axis to any known form, though it
may well belong to some one already described.

ScapulcB. — There are several scapulae, mostly without the coracoid ele-
ments. Certain of them are probably amphibian, but as this point is uncer-
tain the bones are described together for easier comparison.

The first scapula. No. 3059, is undoubtedly that of a Pelycosaur and in
all probability belongs to some species of Dimetrodon. The nearest bone, in
general form, to this is the scaptda in the American Museimi in New York
described by the author as Dimetrodon longiramus (Publication 55, Carnegie
Institution of Washington, p. 56, fig. 16). It differs from the typical Dime-
trodon scapula in the relative shortness of the blade and the greater breadth.
It is almost identical with the D. longiramus, except that the cotylus is some-
what larger (plate 22, fig. 11).

174

THE PERMO-CARBONIFEROUS RED BEDS OF

The remaining scapulas may be divided into two groups: those with a
foramen in the supraglenoid fossa and those without such a foramen. The
first condition mentioned has previously been observed only in the Cotylo-
sauria and in Ophiacodon.

Figure 48, c, d and e, shows two imperfect scapula? of the first kind (No.
3435). The blade is slender and resembles in proportions that of Dimetrodon.
The coracoid portion is wide and rounded in outline ; the sutures can not be
certainly made out, but there are breaks in the normal position of the suttires
and probably follow them. The cotylus is exceptionally deep, with the scapu-
lar face looking almost directly downward. The front limb must have been
held almost at a right angle to the body.

A second scapula. No. 3439 (plate 24, fig. 8) , of similar formbut much larger,
is represented by a nearly perfect scapula and part of the coracoid . The supra-
glenoid foramen occupies the same position and the cotylus is proportionately as
deep . Both this and the smaller specimen show a strong ridge on the outer face

Fig. 48.
(o) anterior edge, (h) posterior edge of imperfect scapula of left side of unnamed reptile, No.

3443, showing curvature of blade. X 5i- , ■ ■•

with coracoid, (e) posterior edge of same, showing cotylus, of unnamed reptile, No. 3435.

( f) articular face for the coracoid elements of the scapula shown in plate 24, figures 6 and 7.
." No. 3437. X 73-

of the blade, probably marking the lower limit of the cleithrum. The supra-
coracoid foramen is very small and lies just beneath the scapular process of the
cotylus. Another (imperfect) scapula (No. 3443), figure 48, a and h, is prob-
ably related to this one, but shows a most remarkable peculiarity in the curva-
ture of the blade, which gives it a strong resemblance to the pubis of Vara iiosa u-
rus. It can not be regarded as a pubis, however, and while a single bone can not
be considered as sufficient material upon which to establish a new order, it is
altogether probable that it indicates the existence of a new group of animals.
It may be that these scapula; with the epicondylar foramina will turn
out to be amphibian.

NORTH AMERICA AND THEIR VERTEBRATE FAUNA.

175

The second type of scapula is represented by two or three different forms.
The first of these (No. 3437) is shown in plate 24, figures 6 and 7 and figure 48, /.
The posterior edge of the blade is slightly injured by decay, but it is apparent
the line was slightly concave. The anterior edge is nearly straight and is
directly continuous with the strong anterior edge of the supraglenoid fossa.
The supraglenoid fossa is much larger than is common, due to the very pos-
terior position of the posterior edge, which carries the articular portion of the
cotylus. The fossa is deep and at its base there is a deep pit in the position
of the foramen in the scapulae described above, but there is no perforation of
the bone. The articular surface for the coracoid elements presents a most
peculiar outline, due to the strong development of the anterior and posterior
edges of the epicondylar fossa.

A fragmentary coracoid (No. 3444, fig. 49, a and h) in the collection evi-
dently belongs with this type of scapula. So far as can be told, the outline

Fig. 49. — Unnamed reptiles. X %■
(a) showing strong ridges and position of the foramen, (t)

articular face for scapula of coracoid. No. 3444.
(c) posterior edge, (d) outer face of scapula of left side.

No. 3436.

was rounded, but the proximal portion, where it articulated with the scapula,
is marked by two strong ridges, between which lies the foramen. The outline
of the articular surface corresponds with the face of the scapula just described.
The peculiarities of these bones indicate the existence of an animal that can
not be placed in any group as yet described ; it is very possible that they belong
to some form of amphibian.

Another form of scapula, resembling the preceding but smaller, is repre-
sented by two specimens, one (No. 3436, fig. 49, c and d) with a fragment of
the coracoid attached and one less perfect. The anterior edge of the blade is
more concave and the whole blade is more slender. The anterior edge of the
supraglenoid fossa is not so prominent and the fossa is less deep, without the
pit. It is possible that these are from immature individuals.

176

THE PERMO-CARBONIFEROUS RED BEDS OF

The last type of scapula (No. 3438) is represented by several imperfect
specimens. It is more like that of Dimetrodon, especially in the region of
the epicondylar fossa, and differs from that form mainly in the short, rounded
coracoid elements. It is probable that this scapula belongs to Theropleura
or some closely related form.

Fig. 50. — a, posterior view of left humerus of Edaphosauriis cruciger, showing ectepi-
condylar foramen. X li. No. 3333.

b, anterior view of same humerus as shown in A.

c, anterior view of lower end of right humerus of Edaphosauriis cruciger, showing

uncrushed condyle for radius and opening of ectepicondylar foramen. X 'A.

In pvtblication No. i8i of the Carnegie Institution the author noted the
presence of an ectepicondylar foramen in the humerus of Edaphosauriis, p.
81. The specimens had not been cleaned at that time and could not be
figured. In figure 50 is shown the form of this bone with the position of the
foramina.

PLATE 5

-j^^^iiSes''

'Mi^^BS-m^mmm:

Fig. 1 . Outcrop of Clear Fork sandstone, a few miles north of Craddocks Ranch, Baylor County. From

the south.
Fig. 2. Same outcrop from the north. The lower part of the sandstone is light bluish, the upper part deep

red and orange. The clays are deep red. This is an isolated mass of sandstone, probably the

deposit of an old stream.

Fig. 1 . Clear Fork beds in Willbarger County near the Seymour- Vernon road. This illustrates the frequent

playing out of the beds laterally.
Fig. 2. Clear Fork beds near the locality shown in fig 1 . The clays are deep red and jointed, the sandstones
light grey. Close to these localities are heavy conglomerate beds and in a small patch of clay
the Lysorophus beds.

CASE

■''^J^-'^k^^E

^^?**?

t^'^^i^

Fig. 1 . Clear Fork sandstone north of Fulda, Baylor County. The dark upper part of the monument is deep
red, the lower part light bluish grey. The unconformity of the beds is well shown.

Fig. 2. Shaly sandstone of the Clear Fork Formation, near the crossing of Godlin Creek on the Archer-Seymour
road. Many fossils have come from this spot.

J!^----^^^

.-if.-.

M^-^ifesfc^.5*;.

'jm&v.,..

>^^

.^vC

Fig. 1 . Cross-section of an old river channel on Craddock's ranch.

Fig. 2. Typical exposure of Wichita Conglomerate on West Coffee Creek, Wilbarger County.

Fig. 3. Heavy sandstone of the Wichita Formation, just east of the Dundee Archer road and

just south of the crossing of the Little Wichita River. A few rods to the west this layer

becomes very thin and finally disappears.

/ I ~i

■^*j-*---r.^. .

.\. . vL£ fit. ' 't ^ -

J^-.*^*.* > ' •'- - -.1-- ~ r^ - : ■■ ..-SVr -'sH**}!

■^ '-'^^'■x^v'■

^# ^j^:#^,;: -;;:^,v V ;: ^ ,,^ |^^5V.-^:?■;^:■ 'i^l

Fig. I . Heavy conglomerate of Wichita age, 8 miles south of Dundee on the Dundee-Archer road.
Fig. 2. Detail of the conglomerate bed shown above.

PLATE 10

i^^^~ ......

IB, . ■-j^^':afS*.

.i«#t.

>:^

^>fe-

r', /i".;S- ..■_ ill-.

'-.feaess,

Fig. I . Clear Fork limeslone a few miles east of tfie Seymour- Vernon road and on the south bank of the
Big Wichita River. The tendency to break into square blocks is well shown.

Fig. 2. Closer view of the same limestone.

Fig 3. Shalv sandstone of the Clear Fork Formation, south of Fulda. The outcrop is typical; it is near such
localities that the bones are frequently found, they seem to indicate the edges of old current beds
where carcasses or fragments which had been carried some distance were lodged.

Fig. I . Triassic beds on San Juan Creek a few miles east of Tucumcari, New Mexico. Tfie badly mixed

character of the beds, so frequent in this region, is well shown.
Fig. 2. Near view, taken not far from the locality shown in figure i. The pinching-out and cross-bedding

is very clear.

CASE

,;.r*''^'^'v^i^

Fig. 1 . Triassic Bad Lands a few miles east of Tucumcari, New Mexico.

Fig. 2. Nearer view of the large pillar shown in the previous figure. The cross-bedded sandstone is under-
lain by bluish sandy clay and this by a purple clay shading into red.

Fig. 3. Upturned Red Beds of Triassic age, on the south side of the valley at Las Vegas Hot Springs, New
Mexico. The lower, western part of these Red Beds may possibly be Permo-Carboniferous.

CASE

ati-r:

^£4:iC-^

Fig. 1 . Contact of the Double Mountain beds with the Dockum, Triassic, in Palo Blanco
Canon, Dickens County, Texas. Line of contact is just above the tilted layer oppo-
site the waist of the figure to the right.

Fig 2. Banded clays in the Bad Lands just east of Tucumcari, New Mexico.

Fig. 3. Nearer view in the same locality. The cross-bedded sandstone is underlain by bluish
sandy clay, this by purple clay down to the hand of the man, and then deep red clay.

..^i^ .

...^>«i".-'!""

• ■ -^ •■" "W*^"**

>•* - *^r.

iSff*

t^^M"%-^^ii ^j^css?^

■■■^»%^^^;^

•>3

■' ; ■■i.''r!;^..

r.-;^^

^-'m;0^^

Fig. I . Minnekata limestone lying on Opechee shale. Sand Creek, 3 miles west of Beulah, Wyoming.
Fig. 2. Minnekata limestone lying on Opechee shale in the west wall of Bear Gulch about 3 miles south
Beulah, Wyoming.

PLATE 15

«*=■„

-^.^^J^-i

Fig. I. Minnekata limestone underlain by Opechee clays, on the railroad in the south limits of Spearfish
South Uakota. 1 he clay immediately below the sandstone is deep purple, below it becomes
deep red.

Fig. 2. Minnekata limestone, about one mile south of Beulah. Wyoming, on the banks of Sand Creek.

PUTE 16

l^-^^^f^^^^Z^Sr

Fig. 1 . Red Mountain south of Laramie. Wyoming. View from tfie north, showing full extent of the Red
Beds, Cretaceous in the foreground. Knight's locality for invertebrate fossils is near the middle
of low hill in the middle of the picture, just above where the white layers stop.

Fig. 2. South side of Red Mountain, south of Laramie, Wyoming, showing the Chugwater (?) red shale
and sandstone.

PLATE 1 7

'"y^'^i-*^

^-*-e«v?--.

Fig. 1. Pinkish, massive beds of sandstone at the top of the Lykins formation, about 2 miles directly east

of Owl Canon, Colorado.
Fig. 2. Upper part of the Red Beds. Chugwater (?), on the south face of Red Mountain, south of Laramie,
Wyoming.

CASE

->45*^'•

..iSt?

Fig. 1 . Near view of the "cross-bedded sandstone" Lyons (?), near Stout, Colorado.

Fig. 2. Massive red sandstone of the Spearfish Formation, about a mile northwest of Beulah, Wyoming.

CASE

PLATE 19

Fig. 1 . Red Sandstone and red clay beds of the lower Wyoming, about 1 6 miles south of Colorado Springs

on the Canon City road.
Fig. 2. Massive red sandstone of the lower Wyoming, Perry Park, Colorado.

PLATE 20

Fig. I. — Restoration of Cricotus hcteroclitas Cope. About one-sixth natural size of an average specimen;
other specimens were considerably larger. The picture gives perhaps rather too strong a suggestion of
the aquatic characters; the animal should be represented as living in a river, to be on the safe side.

^'°- 2 -—Restoration of Eryops megacephalus Cope. About one-tenth natural size of an average specimen.
The tail is represented rather short in consonance with the author's ideas of the creatures.

Fig. 3. — a. Restoration of Diadcctes phaseolinus Cope, about one-tenth natural size; b, anterior view of

same animal.

i'f^^^f^^^V^L^v^V^"' :v^f ^•• ,^3^, V- ■'Mr'- . '■^W'^^y^

- ^^*#- -' -■■^^?*^'--

c-^*>>-* ■

^■'f^-*:

^^^^«c^

-!>^ -'-'^^■" *■■■-, ^- - " '' ■■ " "

§^^'^7^y,y^.'' — ■;:, "

K^ - ->3Utr*r;

' .-J^-';'

:,>p*.

;'¥■;

¥WM

-V^

f>^;: .xAvy

5 it;

■^

Wf^l^^^^^^?v

■-*'^: -^^>^^*i*S?

-jj^tg

Fig. I . Locality of Brier Creek Bone Bed in Archer County, Texas. The material is a light grey clay.
The figures stand upon the outcrop of the bones which lay in part upon a thin bed of conglomerate
composed of small pebbles.
Fig. 2. Nearer view of the bone bed before it was excavated. Fragments below the figure are all bones
and parts of bones.

CASE

PLATE 22

( e,

Fig.
Fig.

1.
2.

Fig.

F.g.

10.

Fig.

II.

Dorsal vertebra of Cncolus showing the supraneural canal. X 0.9.

Outer face of left ilium of Crkolus. No. 3044. X 0.7.

Inner face of right ilium of same. X 0.7.

Lower face of right humerus of Cr/co/us. No. 3419. X 0.74.

Upper face of same. X 0.74.

Lower face of femur of Cricofus. No. 3366. X 0.7.

Lower face of a second femur of Oi'cote. No. 3361. X 0.75.

Anterior face of spine of unnamed amphibian. No. 3294. X 0.7.

Lateral face of same. X 0.7.

Apex of spine of another specimen of the same genus. No. 3^94.

X0.8.

Right scapula of a Pelycosaur, near Dimetwdon longiramus. No. 3059. X 0.5.

CASE

PLATE 23

Fig. 1. Interclavicle of £rt/op5, showing sculpture. No. 3406. X 0.93.

Fig. 2. Proximal end of left clavicle of Er\)ops, sfiowing sculpture. No. 3385. X 0.5.

Fig. 3. Outer face of right cleithrum of Eryops. No. 3408. X 0.3.

Fig. 4. Inner face of same. X 0.3.

Fig. 5. Lower face of femur of an unnamed amphibian. No. 3295. X 0.5.

Fig. 6. Lateral face of same. X 0.5.

Fig. 7. Upper face of left humerus of Archeria robinsoni. No. 3246. X 0.5.

Fig. 8. Lower face of same. X 0.5.

CASE

PLATE 24

■i^^- V

■^•^

'^S

Fig. 1. Lower face of humerus of an unnamed reptile. No. 3354. X O.J.

Fig. 2. Lower face of humerus of a smaller specimen of same. X 0.7.

Fig. 3. Upper face of a specimen of same. X 0.7.

Fig. 4. Upper face of same humerus shown in fia. I. X 0.5.

Fig. 5. Lower face of left femur of unnamed reptile. No. 3363. X 0.9.

Fig. 6. Inner face of right scapula of unnamed reptile. No. 3437. X 0.6.

Fig. 7. Outer face of same. X 0.6.

Fig. 8. Outer face of left scapula of unnamed reptile. No. 3439. X 0.3.

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