LIBRARY

BURFRU 0?

L_ i B R A R Y

SPUMNfe.

Scaphitoid cephalopods

of the 

Colorado group ^ IO UBRAttX 

By W. A. COBBAN .

GEOLOGICAL SURVEY PROFESSIONAL PAPER 239

Evolution ^Scaphites and related genera, with 

descriptions and illustrations of new species 

and a new genus from W^estern 

Interior United States .

UNITED STATES GOVERNMENT PRINTING OFFICE, WASHINGTON : 1951
UNITED STATES DEPARTMENT OF THE INTERIOR 

Oscar L. Chapman, Secretary

GEOLOGICAL SURVEY 

W. E. Wrather, Director

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

Washington 25, D'.'C. - Price $1.50 (paper cover)
CONTENTS

Abstract.. . _________________________________________

Introduction _.______..________..__.___._______-___.__

Characteristics of thescaphites of the Colorado group.. __ 

Scope of the group ..____.-___._________.__._____

Definition of the adult..-.. _.-.__.____.-___.._____

Form _ 1 

Sculpture. 

Suture _ 

Variation _

Page 

1

1

2

2

2

3

3

3

4

4

Scaphite zones____---__ ____________________

Northern Black Hills-_-___--_.___________

Sweetgrass arch._________________________

Evolution of the scaphites of the Colorado group. 

Geographic distribution.______ _________________

Systematic descriptions..______________________

References_____________________________..._

Index ______________________________________

Page 

4

4

5

6

11

18

39

41

ILLUSTRATIONS

Page 

PLATES 1-21. Scaphites of the Colorado Group-_-_____-^.___-____________-_--_----__-_________..-___-___-___-_ Follow index

FiouiiE 1. Lines of scaphite evolution__________________________________________________________________________ 7

2. Sketches illustrating changes in size, form, sculpture, and suture of one lineage of scaphites of Niobrara age_..__ 8

3. Evolution of the trifid first lateral lobe____-_-_____---_-_------------------------------------_-------- 11

4. Index map showing localities of collections from rocks of Colorado age.____-___--____--___-__--__----._-- 12

INSERT

Distribution of scaphitoid cephalopods of the Colorado group and equivalent rocks, by localities. Facing 12 

m
SCAPHITOID CEPflALOPODS OF THE COLORADO GROUP

By W. A. Cobban

ABSTRACT

 Scaphitoid ammonites are locally abundant in rocks of middle 

and late Colorado age in the Western Interioi. These scaphites 

may be divided into two groups on the basis of evolute or involute 

septate coil in the adult. Evolute scaphites, which are known in 

the Western Interior only from the Greenhorn limestone, are not 

treated in this report. Involute scaphites are common throughout much of the Colorado rocks and fall within the genera 

Scaphites, Clioscaphites, and Desmoscaphites. Scaphites is represented by 39 species and varieties, of which 27 are described as 

new. The new genus Clioscaphites is represented by nine 

species and varieties, of which six are new. Desmoscaphites is 

known by. only a single new species.

The adult scaphite is defined as an individual with partly 

unrolled living chamber, a distinctive sculpture, and a constricted 

aperture. The adults range in length from 7.7 mm. to over 100 

mm. At most localities the smallest adult of a species is about 

one-half as long as the largest, but this ratio may be as much 

as 1: 3 or even 1:4.

The scaphites have a considerable range in form. The adults 

of each species grade from small, slender individuals to large, 

stout ones. The large shell is more involute than the small one, 

and its living chamber is less extended. Several species have 

umbilical swellings, and one species has a lateral swelling at the 

base of the living chamber. The aperture, which is moderately 

constricted, has a small dorsal lappet. In addition, a few species 

have lateral and ventral lappets.

The sculpture consists of primary and secondary ribs, and, in 

many species, ventrolateral nodes. Generally, the primarj' ribs 

aie strong and, at the ventrolateral margin, split into two or 

three weaker secondaries. One species has flat-crested and 

uncommonly high ribs that are curved back in cross section.

The external suture has four or five well-defined lobes and 

saddles that decrease in size away from the venter. The saddles 

are bifid, the first being asymmetric. The first lateral lobe is 

bifid in Scaphites, but asymmetrically bifid or trifid in Clioscaphites and Desmoscaphites. The internal suture consists of three 

or four lobes and saddles decreasing in size away from the dorsum.

The scaphites of the Colorado group fall into 15 faunal zones, 

1 in the Greenhorn limestone, 7 in the Carlile shale, and 7 in 

rocks of Niobrara age. The most completely.fossiliferous sections 

known are on the north flank of the Black Hills in South Dakota, 

and on the Sweetgrass arch of north-central Montana. The 

Black Hills section is best for the Greenhorn and Carlile formations, whereas the Sweetgrass arch is most fossiliferous for rocks 

of Niobrara age.

These species seem to have' descended from some form like 

Scaphites aequalis Sowerby of the European Cenomanian. The 

earliest scaphites of the Colorado group, represented by S. 

delicatulus Warren, are part of a cosmopolitan fauna. Subsequent development in the Western Interior is distinctly provincial. Several lineages are indicated. The main line of 

scaphites shows, in the Greenhorn and lower part of the Carlile,

trends toward increase in size, decrease in density of ribbing, and 

simplification of suture. At the beginning of middle Carlile time 

these scaphites suddenly decrease in size, and the maximum 

simplification of the suture is attained. The trend after that 

is toward inciease in size of the adult and toward complexity in 

the suture. This line of scaphites reaches maximum size and 

complexity of suture by middle and late Niobrara time. By 

latest Niobrara time a definite trend toward decrease in size and 

simplification of suture is seen. By the beginning of Niobrara 

time these scaphites show a tendency to become less unrolled, 

and by late Niobrara time, the dorsum of the adult living chamber 

is completely in contact'with the outer septate coil. This tendency to become tightly enrolled is accompanied by a great 

reduction in the size of the umbilicus. The first lateral lobe of 

the suture is more or less symmetrically bifid in the Greenhorn, 

Carlile, and lower Niobrara species, but in the upper Niobrara 

species this lobe passes through an asymmetric phase and 

becomes trifid.

In the late Carlile a split from the main.scaphite line gave rise 

to a new line of species characterized by ventrolateral nodes. 

These scaphites closely paiallel the main line of species by becoming larger, less unrolled, and by developing a suture with trifid 

lobes.

A third lineage is represented by several tiny species. The 

oldest species, of earliest Carlile age, has a nearly normal aperture. Each younger species shows progressive forward extension 

of the lateral maigins of the aperture, and by early Niobrara 

time, prominent lateral lappets developed. By late Niobrara 

time the suture developed trifid lobes.

At the close of Colorado time the native Western Interior 

species were largely replaced by an entirely different type of 

scaphites which had migrated into the area from Europe by way 

of the Atlantic and Gulf Coasts of America.

INTRODUCTION

The scaphites are one of the most abundant and 

easily recognized groups of ammonites in the Upper 

Cretaceous of the Western Interior. They are especially abundant in marine rocks of Colorado age, and 

serve as the best guides for subdividing those beds into 

faunal zones. The scaphites are most abundant in 

dark-gray noncalcareous to somewhat calcareous shale, 

but their presence also in sandy and chalky beds makes 

them particularly useful in correlating diverse lithologic 

units. The earliest scaphites of Colorado age belong 

to an early Turonian cosmopolitan fauna, but their development thereafter is distinctly provincial. This 

makes it possible to study lineages without the disturbing influence of periodic migrations of foreign elements into the local populations.

1
.SCAPHITOID CEPHALOPODS OF THE COLORADO GROUP

This study is based on a collection consisting of about 

300 lots of fossils obtained largely by members of the 

United States Geological Survey from Montana, South 

Dakota, Wyoming, Utah, Colorado, Kansas, and New 

Mexico. Of the 3,300 specimens examined, about 1,500 

were collected by the writer from measured stratigraphic 

sections.

The writer is deeply indebted to Dr. John B. Reeside, 

Jr., of the U. S. Geological Survey, whose broad experience in this field has been of great assistance and 

encouragement. Dr. Ralph W. Imlay and Dr. Roland 

W. Brown, of the U. S. Geological Survey, have offered 

much valuable advise. Thanks are also due Dr. 

Harold E. Vokes, of The Johns Hopkins University, 

for his guidance and many helpful suggestions in completing most of this work as part of a doctor's dissertation. Mr. Nelson W. Shupe, of the U. S. Geological 

Survey, photographed the fossils.,

CHARACTERISTICS OF SCAPHITES OF THE COLORADO

GROUP

The genus Scaphites and closely related genera have 

been discussed fully by Reeside (1927a, pp. 5, 6; 1927b; 

1927c, pp. 20, 21). He summarizes the characters of 

the genus Scaphites as follows (1927a, pp. 5, 6):

* * * a normal coil of septate whorls and the last living 

chamber partly unrolled; whorls stout, umbilicus small, sculpture 

of straight ribs beginning in the umbilicus and passing with increasing height to the margin of the venter, where they split 

into two or more ventral ribs; there are also intercalated ventral 

ribs, and there may be definite nodes at the ventrolateral ends 

of the primary ribs; the suture consists of moderately incised 

elements, decreasing gradually in size from the median plane to 

the line of involution; lobes trifid in the earliest stages but usually 

bifid in the adult. Nowak called this group Holcoscaphites, but 

Parkinson's name [Scaphites] should be retained in a restricted 

sense.

The writer accepts this definition and is applying it 

in a broad sense. However, it is possible to subdivide 

the scaphites of the Colorado group into several groups 

of species as follows: ,

A. Adult septate coil subevolute to evplute. (Not treated in this

work.). 

B. Adult septate coil involute.

a. Small forms with living chamber moderately to considerably freed from the septate coil. Suture simple, 

symmetrically bifid first lateral lobe. Scaphites. 

tetonensis 

sagensis 

frontierensis 

uintensis 

corvensis 

nigricollensis 

whitfieldi 

ferronensis 

warreni 

veterinovus

carlilensis

morrowi

arcadiensis

larvaeformis

patulus

praecoquus

delicatulus

. b. Large forms with living chamber moderately to slightly 

freed from the septate coil. Suture moderately complex, first lateral lobe either symmetrically or asymmetrically bifid. Scaphites.

binneyi A . interjectus

depressus

ventricosus

preventricosus

c. Large forms with living chamber not freed from the 

septate coil. Suture typically complex, first lateral 

lobe trifid or asymmetrically bifid. Clioscaphites.

novimexicanus

choteauensis

vermiformis

platygastrus 

 montanensis

saxitonianus

d. Moderate sized forms with living chamber not freed from 

septate coil. Constrictions on early whorls. Suture 

typically complex, first lateral lobe trifid. Desmoscaphites.-

erdmanni

e. Moderate sized forms with living chamber freed from 

septate coil. 'Ribs strongly recumbent and may have 

flat crests. Suture simple, symmetrically bifid first 

lateral lobe. Scaphites.

impendicostatus

mariasensis

f. Small forms with living chamber considerably fieed from 

septate coil. Aperture of adult with prominent lateral 

lappets. Suture simple, fiist lateral lobe bifid or 

trifid. Scaphites.

coloradensis

auriculatus

DEFINITION OF THE ADULT

The most characteristic feature of the scaphites is 

that the last living chamber is partly unrolled. The 

sculpture on this last living chamber is entirely different from that of the septate whorls. It is this sculpture 

that readily distinguishes a species, whereas the sculptural features of the internal whorls of many species 

are almost identical. The last living chamber commonly has strong primary ribs that may end in ventrolateral tubercles, the ventral ribs may be uniformly spaced 

or widely spaced on one part and closely spaced on 

another, and the aperture is always constricted. Lateral 

lappets may be present. The adult scaphites are here 

defined as those individuals with partly unrolled living 

chamber bearing a distinctive sculpture and ending 

with a constricted aperture. Immature specimens 

that have the living chamber preserved do not differ
CHARACTERISTICS OF SCAPH'ITES OF THE COLORADO GROUP

in shape and sculpture from the internal septate whorls 

at comparable diameters of adult specimens. 

SIZE

The scaphites of the Colorado group show a great 

range in size. The smallest known adult is a specimen 

.of Scaphites coloradensis, 7.7 mm. long, from rocks of 

late Niobrara' age. $. ventricosus, S. depressus, and 

Clioscaphites montanensis, of middle and late Niobrara 

age, attain lengths as great as 100 mm. The average 

length of 550 adults from all the scaphite zones of the 

Colorado group is 39.2 mm. (1.5 inches).

In any collection from any one locality a considerable 

range in size of the adults is noteworthy. The smallest 

individual is commonly about one half as long as the 

largest (pi. 18, figs. 7, 23, 24), and in some instances 

(compare pi. 18, fig. 23 with pi. 19, fig. 9), this ratio

may be 1:3 or 1:4.

FORM

In all the scaphites of the Colorado group the umbilicus is wide in the first few whorls and narrow in the 

later ones. The umbilical shoulder rounds evenly into 

the narrow, steeply inclined umbilical wall and into the 

flattened or broadly rounded flanks. The whorl cross 

sections are normally wider than high, but the youngest 

whorls of the scaphites of late Carlile age may be as 

high as wide, or occasionally higher than wide (pi. 5, 

fig. 2). The venter of most species is well rounded to 

broadly rounded, but the last septate whorl of Clioscaphites vermiformis (Meek and Hayden) may have a 

flattened venter, and the new variety C. v. toolensis 

may even have a broadly depressed venter near the 

orad end of the septate cott. The venter rounds evenly 

into the flanks, and in many species it is difficult to determine where one passes into the other. Because of this 

difficulty and to maintain a uniform scheme of description, the point where the primary ribs fork is taken as 

the margin of the venter in most specimens. This is the 

point where the primaries commonly attain their greatest height or where tubercles may develop. Using this 

as a guide the scaphites have a much greater area in the 

venter than most other ammonites have.

On the third or fourth whorls succeeding the protoconch the ventrolateral margin is subangular to sharply 

rounded and, on many individuals, it is raised into a 

thickened ridge. On earlier and later whorls the 

ventrolateral margin is considerably more rounded.

The body chamber is large, making up one-half to 

three-fourths of a whorl. In Scaphites the adult living 

chamber is slightly to almost wholly freed from the 

septate coil. Where only slightly freed from the 

septate coil, it is the younger part of the living chamber 

that is not in contact with the coil. In Desmoscaphites 

and. Clioscaphites, n. gen., the living chamber is wholly

or nearly entirely in contact with the outer septate 

whorl. All specimens have a persistent dorsal furrow on 

the freed body chamber. The aperture is reniform in 

cross section and moderately constricted. A small, 

broad dorsal lappet is present in all adults. It is most 

conspicuous in Scaphites, especially hi some of the 

species of Carlile age (pi. 5, fig. 25; pi. 6, fig. 5). Scaphites tetonensis and S. impendicostatus, n. spp. have the 

ventral margin of the aperture bent away from the 

septate coil. In the latter species the shell is thickened 

along the ventral margin (pi. 11, fig. 8). Two tiny 

species of Niobrara age, S. auriculatus and S. coloradensis, n. spp., have dorsal, ventral, and lateral lappets; 

the last is narrow, pointed, and directed laterally.

An umbical swelling occurs at the base of the adult 

living chamber of $. delicatulus Warren and S. impendicostatus, and in a few specimens of S. larvaeformis Meek 

and Hayden, S. patulus, n. sp., Clioscaphites montanensis, n. sp., and C. novimexicanus (Reeside). Many 

specimens of S. nigricollensis, n. sp. have a lateral 

swelling at the base of the living chamber.

SCULPTURE

The sculpture consists of numerous primary (umbilical) and secondary (ventral) ribs, and in addition, 

many species 'have a row of ventrolateral .tubercles 

which may be round or radially elongate. The primary 

ribs are inclined backward as they cross the umbilical 

wall, and on reaching the umbilical shoulder, bend 

forward and cross the flank with a forward inclination 

of 15° to 45°. At the ventrolateral margin (about half 

way from the umbilical seam to the middle of the 

venter) the primaries attain their greatest height and 

then split into two or three weaker secondaries. These 

may (1) extend straight across the venter, as on the 

living chamber of Scaphites ventricosus Meek and 

Hayden (pi. 12), (2) cross'the venter with a backward 

bending, as on the last septate whorl of S, patulus, n. sp. 

(pi. 1, fig. 27), (3) cross the venter with a forward arching, as on S. whitfieldi, n. sp. (pi. 4, fig. 37), or (4) curve 

back from the ventrolateral margin and then cross the 

middle of the venter with a forward arching, as on the 

immature stages of Clioscaphites vermiformis (Meek and 

Hayden) (pi. 18, figs. 12-18). Intercalated ribs are 

common between the paired secondaries and begin at 

the point of furcation or below it on the flanks. The 

ribs are either sharp or rounded, but one species, 

Scaphites impendicostatus, n..sp. (pi. 11), possesses 

flat-crested as well as unusually high ribs that are 

curved backward in cross section. Pointed, round 

tubercles are present in S. delicatulus; S. larvaeformis, 

S. patulus, S, praecoguus, n. sp.., S. arcadiensis Moreman, 

S. uintensis, n. sp., S. frontierensis, n. sp., S. sagensis, 

n. sp., S. binneyi Reeside, Clioscaphites vermiformis, C.
platygastrus, n. sp., <?.? choteauensis, n. sp., and Desmoscaphites erdmanni, n. sp.

SUTURE

The suture ranges in complexity from the simple 

pseudoceratitic type characteristic of the middle 

Carlile species to the highly incised form of the late 

Niobrara species. The external suture has four or five 

clearly defined lobes and saddles progressively decreasing in height away from the venter. The saddles 

are bifid, and the first is asymmetric with the widest 

part on the ventral side. The first lateral saddle is 

always wider than the second, but the second may or 

may not be broader than the third. The first lateral 

lobe is bifid in Scaphites and trifid or asymmetrically 

bifid in Clioscaphites and Desmoscaphites. The second 

lateral lobe is typically bifid in the early Carlile 

species, but commonly trifid in those from the late 

Carlile and Niobrara. The rest of the external lobes 

are trifid, bifid, or undivided. The internal suture 

consists of three or four lobes and" saddles decreasing 

in size away from the middle of the dorsiim. The dorsal 

lobe is long, slender, and trifid. The first internal lobe 

is bifid or trifid and may be nearly as large as the dorsal 

lobe. The remaining lobes are small and commonly 

bifid. The internal saddles are small and bifid.

VARIATION

The scaphites are a highly varied group. The adults 

of each species grade from small, slender forms to large, 

stout forms. Because of the more.slender whorls, the 

small adults are less involute and the living chamber is 

more freed from the septate coil (compare pi. 1, figs. 

8, 16;pl. 15,figs. 1,7). In many species the ribs tend to 

be denser and weaker on the living chambers of the larger 

adults (pi. 7, figs. 6, 12). In some species the large and 

small adults.differ considerably in shape and sculpture, 

and perhaps only the use of large collections that show 

the intergradations prevents mistaking the large and 

small forms for different species. For example, the 

internal molds of the living chambers of the large, stout 

form of Scaphites nigricollensis, n. sp. tend toT^e smooth 

and commonly are inflated laterally near the base 

(pi. 6). In contrast the internal molds of the small, 

slender form are strongly ribbed and show no trace of 

lateral swellings (pi. 5, figs. 11-25). In dealing with 

such varied species, varietal names are useful.

SCAPHITE ZONES

The most completely fossiliferous sections containing 

scaphites are on the flanks of the Black Hills and on the 

Sweetgrass arch of north-central 'Montana. The Black 

Hills section includes nearly all the zones of the Greenhorn and Carlile formations, and the Colorado shale of

the Sweetgrass arch demonstrates nearly all the zones 

of Niobrara age.. Collections from other localities in 

the Western Interior indicate that the Black Hills and 

Sweetgrass arch sequences each lack a scaphite zone, 

which may indicate hiatuses or that the particular ages 

may be represented by poorly fossiliferous or unfossiliferous beds. Scaphites have not been found in the 

Western Interior in pre-Greenhorn strata.

NORTHERN BLACK HILLS

The Niobrara formation of the Black Hills contains 

few fossils other than Inoceramus fragments, Ostrea 

congesta Conrad, Foraminifera, and fish bones. Scaphites have not been found in the Niobrara formation 

but the Carlile shale contains a rich scaphite fauna, 

and the underlying Greenhorn formation has yielded 

some specimens. .

The folio whig generalized section shows the major 

lithologic units that compose the Greenhorn, Carlile, 

and Niobrara formations and the scaphite species found 

in each. This section was measured 4 to 9 miles north 

of Belle Fourche, S. Dak.

Niobrara formation (200 feet) . Feet

16. Chalk marl, weathers white; interbedded with

many thin layers of bentonite_____________ 200

Carlile shale (546 feet)

Sage Breaks member (194 feet)

15. Shale, dark-gray; weathers dark; contains 

abundant gray-weathering calcareous concretions that are septarian, with thick seams 

of brown, yellow, and white calcite. Scaphites corvensis, n. sp_____J_______.______ 194

Turner sandy member (258 feet)

14. Shale, gray, finely sandy; weathers buff gray; 

contains tan- and yellow-weathering calcareous concretions. Scaphites corvensis, n. 

sp., near top, S. nigricollensis, n. sp., in 

middle, and S', whitfieldi, n. sp., at base___- 89

13. Shale, dark-gray; weathers dark; contains 

some sandy beds and numerous rusty- and 

reddish-weathering ferruginous concretions. 

Scaphites whitfieldi, n. sp., and S. pisinnus, 

n.sp_______-__-_________________---_ 82

12. Shale, dark-gray; weathers medium gray; contains large yellow-weathering calcareous concretions and small gray-weathering calcareous concretions. Scaphites warreni Meek 

and Hayden in lower half._______________ 47

11. Shale, gray, very sandy; weathers mediumgray ; contains large yellow-weathering sandy 

calcareous concretions at top and in middle; 

chert pebbles and coarse sandstone at base. 

Scaphites warreni Meek and Hayden and 

S. veterinovus, n. sp___ _________________ 40

Unnamed shale member (94 feet)

10. Shale, dark-gray.__________________________ 13

9. Shale, dark-gray; weathers medium-gray; contains numerous ferruginous concretions . 

weathering orange tan, rusty, and darkmaroon. Scaphites carlilensis Morrow and 

S. arcadiensis Moreman_________________ 24
SCAPHITE ZONES

Carlile shale Continued Feet 

 Unnamed shale member Continued

8. Shale, dark-gray, slightly sandy-.-____-_-___ . 26

7. Shale, black-gray, hard_-_---_-_--__--_-._-. 18 

6. Shale, dark-gray, slightly calcareous, weathers 

bluish gray; contains light-gray limestone 

concretions at top. Scaphites larvaeformis 

Meek and Hayden, S. patulus, n. sp., and S. 

praecoquus, n. sp---__-__-.-__-___._____ _ 13

Greenhorn formation (312 feet)

5. Shale, gray, calcareous; weathers white; contains thin lenses and shaly layers of limestone__---_--_i_.--_..-__.__-_-__--_----- 37

4. Shale, gray, calcareous; weathers white; contains white-weathering limestone concretions. 26 

3. Shale, black-giay, noncalcareous; contains small

yellow limonite nodules________________.:__ 22

2. Shale, giay, calcareous; weathers gray; contains 

ferruginous concretions and ferruginous shaly. 

layers weathering rusty. Scaphites delicatulus 

Warren._..._........._____.___.._.__.._- 70

1. Shale, gray, slightly calcareous-, weathers giay... 157

 In the Black Hills section the scaphites occur in the 

following sequence:

Carlile shale

Zone of Scaphites corvensis, n. sp.

Zone of Scaphites nigricollensis, A. sp.

Zone of Scaphites ivhilfieldi, n. sp.

Zone of Scaphites ivarreni Meek and Hayden

Zone of Scaphites carlilensis Morrow

Zone of Scaphites larvaeformis Meek and Hayden . Greenhorn formation

Zone of Scaphites delicatulus Warren

The beds from which the scaphites of the lower four 

zones of the Carlile shale were collected are separated by 

unfossiliferous shale. This may explain the fact that 

the ranges of the species do not overlap. In contrast, 

the Turner sandy member containing S. whitfieldi, 

S. nigricollensis, and S. corvensis is fossiliferous throughout and, apparently, there are no breaks in sedimentation. The result is that transitional forms occur between the species of each of these zones.

Collections from the top of the Frontier formation of 

the Laramie Basin of southeastern Wyoming and from 

the Mancos shale of central Utah and northwestern 

New Mexico contain a scaphite species.intermediate between S. warreni and $. whitfieldi that occurs between 

the zones of these species. This species, S.ferronensis, 

n. sp., may eventually be found in the upper part of 

unit 12 of the northern Black Hills section.

SWEETGRASS ARCH

The Colorado shale of the Sweetgrass arch contains 

equivalents of the Colorado group of the Black Hills. 

The beds equivalent to the Greenhorn and Carlile formations are lithologically similar to those of the Black 

Hills but considerably thinner. In contrast the beds

equivalent to the Niobrara formation are several times 

as thick and, unlike the Niobrara formation, are composed almost entirely of dark-gray noncalcareous shale. 

Scaphites have not been found in the Greenhorn equivalent, and only two zones can be recognized in the rocks 

of Carlile age. The overlying shale, however, contains 

the richest known scaphite faunas of Niobrara age.

The following generalized section shows the major 

lithologic units of that part of the Colorado shale equivalent to the Greenhorn, Carlile, and Niobrara formations of the Black Hills. The beds of Greenhorn and 

Carlile age were measured along Sun River valley west 

of Great Falls, and the Niobrara rocks were measured 

on the west and south flanks of the Kevin-Sunburst 

dome.

Colorado shale

Beds equivalent to the Niobrara formation (620 feet) Feet 

12. Shale, dark-gray; " contains gi ay-weathering 

calcareous concretions and about 10 thin 

layers of bentonite Clioscaphites novimexicanus (Reeside), Desmoscaphites erdmanni, 

n. sp., and Scaphites leei Reeside in upper 

part; Clioscaphites"! choteauensis,_ n. sp., in 

middle part; Clioscaphites montanensis, n. 

sp., C. vermiformis (Meek and Hayden), 

C. saxitonianus (McLearn), and Scaphites 

coloradensis, n. sp., in lower part...__-___- 200 

11. Shale, dark-gray; contains ferruginous concretions weathering rusty and reddish brown 

and calcareous concretions weathering gray, 

buff, and yellow. Very few bentonite beds. 

Scaphites ventricosus Meek and Hayden and 

S. tetonensis, n. sp. in lower half..________ 180

10. Shale, dark-gray, contains abundant grayweathering calcareous concretions and about 

40 layers of bentonite. Scaphites preventricosus, n. sp., S. impendicostatus, n. sp., and 

S. auriculatus, n. sp., in upper two-thirds. 

S. mariasensis, n. sp., in lower third.____-_ 240

Beds equivalent to the Carlile shale (155 feet)

9. Shale, dark-giay, sandy, hard; weathers bluish 

gray; contains gray- to yellow-weathering 

calcareous concretions and rarely a chertpebble layer. Scaphites nigricollensis, n. sp_ 100 

8. Shale, dark-gray, finely sandy; contains numerous ferruginous concretions weathering 

rusty to reddish brown. Scaphites carlilensis 

Morrow_ _____________________________ 25

7. Shale, dark-gray, finely sandy, hard___-__._- 30 

, Beds equivalent to the Greenhorn limestone (55 feet) 

6. Chalk rnarl, dark-gray; weathers buff; contains thin gray limestone lenses and thin 

layers of bentonite_________._-_______.__ 12

5. Shale, gray, calcareous.--__-_____-__--___.- 19

4. Chalk mar], dark-gray; weatheis light blue_ 8 

3. Bentonite, creamy white______-__-_--__-__. 3

2. Shale, brownish, soft, papery, noncalcareous __ 12 

1. Chalk marl, gray; weathers buff; contains 

small ferruginous concretions and larger 

gray-weathering calcareous concretions _.. 1
6 SCAPHITOID CEPHALOPODS OF THE COLORADO GROUP

The rarity and poor preservation of fossils in the beds 

of Garlile age may account for the recognition of only 

two of the six scaphite zones known in the Carlile shale 

of the Black Hills. However, Scaphites nigricollensis 

occurs so close above the beds containing S. carlilensis 

that probably the zones of S. warreni, S. ferronensis, 

and S. whitfieldi are absent or they are represented by 

very thin, unfossiliferous zones.

The shale of Niobrara age shows the following 

scaphite zones.

Zone of Clioscaphites novimexicanus (Reeside) 

Zone of Clioscaphites? choteauensis, n. sp. 

Zone of Clioscaphites montanensis, n. sp. 

Zone of Scaphites ventricosus Meek and Hayden 

Zone of Scaphites preventricosus, n. sp. 

Zone of Scaphites mariasensis, n. sp.

This is the most complete record known for beds of 

Niobrara age. However, collections from the Cody 

shale of the Bighorn Basin, Wyoming, reveal a species, 

Scaphites depressus Reeside, intermediate in form 

between S. ventricosus and Clioscaphites montanensis 

and occurring between those zones. On the Sweetgrass 

arch S. ventricosus and C. montanensis are found. in 

such close stratigraphic proximity that probably the 

S. depressus zone is absent. Phosphatic nodule layers 

present in the shale just above the highest occurrence 

of S. ventricosus also suggest hiatuses in this part of the 

sequence.

EVOLUTION OF THE SCAPHITES OF THE COLORADO

GROUP

Spath (1934, p. 498) has pointed out that the family 

Scaphitidae may have had its origin in the Lytoceratidae 

of the Mediterranean-Equatorial region, and that the 

earliest known scaphites occur in the upper Albian. 

These early scaphites are tiny and have either evolute 

or involute septate whorls in the adult stage. The 

sutures are moderately incised and consist of but few 

elements. The suture of Scaphites circularis Spath 

(1937, p. 501, text fig. 175d) from the English Gault 

has only six lobes and six saddles. These little scaphites are comparatively rare in the Albian, but in the 

Cenomanian they are more abundant, especially S. 

aequalis Sower by. The sutures of the Cenomanian 

forms seem to be less incised than those of their Albian 

ancestors.

In America the oldest described scaphite is Worthoceras 

worthense (Adkins and Winton) (1920, p. 36, pi. 7, figs. 

1, 2), a slightly evolute form from the Duck Creek 

limestone of the basal upper Albian of Texas. Scaphites 

hilli Adkins and Winton (p, 37, pi. 7, figs. 3-6) of the 

Pawpaw formation of the uppermost Albian of Texas 

is an involute form. The lower Cenomanian Grayson 

shale of Texas has yielded a tiny involute scaphite, S.

bosquensis Bose (1928, pi. 224, pi. 7, figs. 1-6), and a 

larger evolute form, S. subevolutus Bo'se (p. 225, pi. 7, 

figs. 7-30; pi. 18, fig. 8). Several small involute and 

evolute scaphites have been described from the Cenomanian of Oregon and California by Anderson (1902).

Scaphites have not been found in the Cenomanian 

Woodbine group of Texas (L. W. Stephenson, personal 

communication), or in the equivalent beds of the 

Western Interior.

The lower Turonian zone of Sciponoceras gracile 

(Shumard) marks the first widespread occurrence of 

scaphites in North America. Scaphites delicatulus Warren (1930, p. 66, pi. 3, fig: 3; pi. 4, figs. 7, 8) is known 

from the Alaskan arctic slope, from basal Turonian 

rocks of the Mackenzie River valley of northwestern 

Canada, from the lower part of the Smoky River shale 

.of the Grande Prairie district of north central Alberta, 

from the Greenhorn formation of the Black Hills, and 

from equivalent beds in the Cody shale on the northeast flank of the Bighorn Mountains. S. brittonensis 

Moreman (1942, p. 215, pi. 34, figs. 1, 2; text fig. 2r), 

from the Eagle Ford group of Texas, very closely resembles S. delicatulus and is also associated with 

Sciponoceras gracile (Shumard). The resemblance of 

these scaphites to S. aequalis Sowerby of the European 

Cenomanian is striking. This close similarity, and the 

absence of scaphites in the post-Grayson Cenomanian 

rocks of the Gulf Coast and Western Interior, suggest 

that S. aequalis gave rise to S. delicatulus through some 

transitional form that migrated to America during the 

early Turonian.

Scaphites delicatulus var. greenhornensis, n. var., from 

the Greenhorn formation differs from the typical form 

of the species chiefly in possessing coarse ribbing on 

the curved part of the living chamber and in having 

proportionally more primary ribs and fewer secondaries 

on the living chamber. From this type of ancestor S. 

larvaeformis Meek and Hayden of the basal Carlile 

shale was probably derived. This species differs from 

S. d. greenhornensis in having fewer ribs and a smaller 

umbilical swelling. About one-half of the specimens 

of S. larvaeformis at hand have coarse ribbing on the 

last half'of the living chamber although not as coarse 

as on the Greenhorn variety. S. praecoquus, n. sp., 

can be interpreted either as a split from S. larvaejormis 

or as a tiny variant that developed an uncoiled living 

chamber before other adult features were fully 

developed. It appears to mark the beginning of 

a line of small scaphites that by Niobrara time 

had developed prominent lateral lappets. S. patulus, 

n.' sp., also of the basal Carlile, is either a split from 

S. larvaeformis or a descendent of S. delicatulus that 

developed a more curved and strongly sculptured 

living chamber considerably depressed in cross section.
EVOLUTION OF THE SCAPHITES OF THE COLORADO GROUP

NIOBRARA 

FORMATION

novimcxicanus

coloradensis montanensis 

depressus 

ventricosus

auriculatus preventricosus 

preventricosus

erdmanni

ckoteauensis

saxitonianus vermiformis

binneyi

impendicostatus

manasensis

 platygaslrus

CARLILE 

SHALE

pist-nnus

vctcrinovtis

nigricollensis 

mhitfieldi

ferronensis

carlilensis arcadiensis

praecoquus larvaeformis patulus

GREENHORN 

LIMESTONE delicatulus

FIGURE 1. Lines of scaphite evolution.

S. patulus and S. larvaeformis show backward bending 

of the ribs crossing the venter on the last septate whorl, 

a character found in many early scaphites throughout 

the world.

Scaphites carlilensis Morrow, which marks the zone 

.next above that of S. larvaeformis, is most abundant in 

the Blue Hill .shale member of the Carlile shale of Kansas, and inlithologically similar beds that formmostof the 

unnamed shale member of the lower part of the Carlile 

shale of the northern Black Hills. S. carlilensis attains 

a larger size than S. larvaeformis and the suture is less 

incised. There is. further reduction in the number of 

ribs, and these are now uniformly spaced on the venter 

of the living chamber. Tubercles and umbilical swelling are lacking. The associated species, S. arcadiensis 

Moreman, still maintains ventrolateral tubercles and a 

depressed cross section of the living chamber, suggesting 

derivation from S. patulus. The tubercles, however,

are, much less conspicuous and tend to become high 

primary ribs. Both $. carlilensis and S. arcadiensis 

have lost the rursiradiate ribbing of the ventral ribs on 

the last septate whorl.

Scaphites warreni Meek and Hayden characterizes 

the lower third of the Turner sandy member of the 

Carlile shale of the Black Hills and equivalent sandy 

beds in eastern Wyoming, Colorado, and New Mexico. 

This species is smaller than its ancestor, S. carlilensis, 

possibly because of an unfavorable environment. The 

sediments containing S. warreni are sandy and, in 

central Utah, pass into cobble beds and variegated 

clays of nonmarine origin reflecting contemporary 

orogenic movements west of the region. The scaphite 

suture became progressively simpler after Cenomanian 

time and reached its simplest state attaining a-pseudoceratitic stage in this species (pi. 3, figs. 8, 20, 22). The 

trend for ribbing to become dense on the curved part
SCAPHITOID CEPHALOPODS OF THE COLORADO GROUP

nommexicanta

deprcssus

vcnlricosus

preventricosus

FIGURE 2. Sketches illustrating changes in size, form, sculpture, and suture of one lineage of scaphites of Niobrara age.
EVOLUTION1 OF THE SCAPHITES OF THE COLORADO GROUP

of the living chamber continued, and in this species, 

the ribbing is more closely spaced than on the straight 

part. The tiny species, S. veterinovus, n. sp., continued 

the line of small species initiated with S. praecoguus 

of the basal Carlile. The ventrolateral edges of the 

aperture are produced outward faintly, foreshadowing 

the development of lateral lappets by Niobrara time.

Scaphites ferronensis, n. sp., which developed out of 

S. warreni, continued the trend toward denser ribbing. 

Many individuals are fairly quadrangular in side view.

Scaphites whitfieldi, n. sp., was derived from S. 

ferronensis by assuming a more quadrangular shape, 

and the dense ribbing that characterizes the younger 

part of the older species spread over the entire living 

chamber and made $. whitfieldi the most densely 

ribbed scaphite of the Carlile. This ribbing is evenly 

spaced. The suture, which was simplest in S. warreni 

and S. ferronensis, developed slightly longer elements, 

initiating a trend toward complexity. S. pisinnus, 

n. sp., which occurs with S. whitfieldi, is similar in size 

to $. veterinovus but has a greater lateral extension of 

the aperture.

Scaphites nigricollensis, n. sp., of the upper part of 

the Turner sandy member of the Carlile shale descended 

from S. whitfieldi, but is larger and stouter. The 

density of ventral ribs decreased and the number of 

primaries increased. The sutures of the two species are 

similar.

Scaphites corvensis, n. sp., of the Sage Breaks member 

and uppermost part of the Turner sandy member, 

continued the trend toward stoutness and increase in 

size that was initiated with S. nigricollensis. The suture 

of the younger species has proportionally longer lobes 

and saddles.

The scaphites of Niobrara age show four lineages. 

The tiny forms with abnormal apertures produced the 

new species S. auriculatus and S. coloradensis. The 

main line of scaphite development (S. delicatulus 

through S. corvensis) flourished to the end of Niobrara 

tune. A split from this line probably in the uppermost 

part of the Carlile, gave rise to a very prominent group 

of scaphites that ranged through the Niobrara and into 

the basal Montana group (as Desmoscaphites bassleri 

Reeside). The new species, Scaphites uintensis, S. 

frontierensis, and S. sagensis, of early Niobrara age, 

represent a fourth line of scaphites, but these species 

are rare and their relationsip to the other scaphites is 

unknown.

Scaphites auriculatus is the earliest of the Niobrara 

species of the praecoguus-veterinovus-pisinnus line of 

scaphites. The lateral extensions of the aperture 

developed into prominent lappets directed outward 

and forward. The suture is simple and shows a bifid

first lateral lobe. S. coloradensis of late Niobrara age 

has a trifid first lateral lobe..

Scaphites corvensis gave 'rise to S. preventricosus, 

n. sp., by further increase in size, stoutness, and 

complexity of suture. The living chamber of S. 

preventricosus is less extended from the septate coil. 

S. ventricosus Meek and Hayden, from the next younger 

zone, shows till further increase in size, stoutness, and 

suture complexity. The living chamber is less unrolled 

and, conversely, more curved. From $. ventricosus 

came S. depressus Reeside, which attains a very large 

size and great stoutness. The living chamber is so 

little unrolled that only in the more slender forms 

(S. depressus vars'. stantoni Reeside and oregonensis 

Reeside) is the younger part freed from the septate 

coil (pi. 15, figs. 1, 7).

Clioscaphites montanensis, n. gen. and sp., descended 

from S. depressus and shows the following trends away 

from that species: (1) decreased size, (2) less unrolled 

living chamber, in contact with the septate coil, (3) 

reduction in size of umbilicus, (4) flattening of flanks, 

(5) increasing number of ventral ribs on the living 

chamber in comparison to the primaries, and (6) 

suture with first lateral lobe transitional from bifid to 

trifid. The scaphite suture attains its greatest degree 

of complexity in this species.

Clioscaphites novimexicanus (Reeside) of the youngest 

Colorado beds was derived from C. montanensis by 

further decrease in size, greater flattening of the flanks, 

increase in density of ribbing, and perfection of the 

trifid first lateral lobe. The suture became simplified, 

thus reversing the trend toward complexity that 

prevailed since middle Carlile time.

Clioscaphites saxitonianus (McLearn) may represent 

an evolutionary line that split off from Scaphites 

ventricosus. . Scaphites mariasensis, n. sp., from beds of early 

Niobrara age, is the oldest known species of a new line 

of scaphites that split off from the main line in the late 

Carlile. The characteristic features of this species are 

its high, sharp ribs and its fairly simple suture with 

broad first lateral lobe.

Scaphites impendicostatus, n. sp., descended from S. 

mariasensis by acquiring stronger sculpture with the 

ribs curving backward in cross section, and on the more 

stout individuals, becoming flat-crested (pi. 11, figs. 

1, 2, 4, 5, 7). The ventral margin of the aperture is 

bent outward slightly. A prominent umbilical swelling 

is present on the large, stout specimens. The suture 

is as simple as that of its ancestor from the basal 

Niobrara. The two main branches that make up the 

first lateral lobe are deeply bifid, making the bifurcating 

saddles almost as high as the main saddle of the lobe.
10

This initiates a new type of suture that persisted through 

several faunal zones.

Scaphites tetonensis, n. sp., which occurs in the zone 

next above that of S. impendicostatus, shows the following trends away from that species: (1) reduction in 

stoutnesskwith loss of the umbilical swelling, (2) reduction in defisity and strength of ribbing, with the ventral 

ribs on the older or straight part of the living chamber 

sparser than oil the younger or curved part, and 

(3) elevation of the ventral extremities of the primary 

ribs into elongate incipient nodes. Trends initiated 

with S. impendicostatus that persisted through S. 

tetonensis are the outward-bent ventral lip of the 

aperture and the form of the suture. The suture is a 

little more" incised and continued to have high lateral 

saddles on the first lateral lobe. These are as high as, 

or even higher than, the main saddle of the lobe.

Scaphites. binneyi Reeside occurs in the zone next 

above that of S. tetonensis. This younger species has 

ventrolateral tubercles that developed out of the 

elevated ventral extremities of the primary ribs of 

S. tetonensis. The suture became slightly more incised 

and continued to have high lateral saddles on the first 

lateral lobe. These may be considerable higher than 

the central saddle of the lobe (pi. 14, fig. 16). S. 

interjectus Reeside, which occurs with S. binneyi, is 

actually a more advanced form judging by the less 

unrolled living chamber. The' ribbing is denser than 

on S. binneyi but the sutures are similar.

Clioscaphites vermiformis (Meek and Hayden) descended from Scaphites binneyi or S. interjectus. It 

became so little unrolled that the dorsum of the living 

chamber was completely in contact with the last septate 

whorl. The sculpture became considerably stronger, 

and the ribbing on the internal whorls developed a 

pronounced forward arching on crossing the venter. 

The suture is fairly simple and characterized by trifid 

lobes. The development of trifid lobes out of symmetrically bifid lobes is not clear in this group of 

scaphites for the change appears to have taken place 

suddenly. However, if transition faunas are found 

between the zones of Scaphites binneyi and Clioscaphites vermiformis, the sutures may have asymmetrically 

bifid first lateral lobes, such as those of Clioscaphites 

montanensis. An alternate possibility is that the trifid 

lobe developed directly out of a symmetrically bifid 

lobe by the lateral saddles of the lobe having become so 

high and large as to reduce the inner or apicad prongs 

of the lobe to a single branch (pi. 14, fig. 16).

An interesting split from C. vermiformis is seen in C. 

platygastrus, n. sp., in which the ribs became high and 

sharp, the primaries lengthened, and the venter flattened. A sharp-ribbed variety of C. vermiformis (pi. 

18, figs. 20, 21) is transitional to this species.. This

new line of scaphites continued into the Telegraph 

Creek formation of earliest Montana age, where it is 

represented by an undescribed species with a more 

compressed form and finer sculpture.

Clioscaphites? choteauensis, n. sp., marks the zone 

next above that of C. vermiformis and shows the following trends away from that species: (1) more rounded 

venter, (2) denser ribbing, (3) smaller ventrolateral 

nodes, and (4) more complex suture.

Desmoscaphites erdmanni, n. sp., occurs at the top 

of the Colorado shale. It was derived from Clioscaphites? choteauensis by further reduction in the size 

of the tubercles and by developing nearly uniform 

spacing of the ventral ribs on the living chamber. The 

internal whorls have the ribs crossing the venter bent 

forward as in Clioscaphites vermiformis, but about five 

constrictions are present on each complete whorl. 

Clioscaphites? choteauensis, which occurs in the zone 

between C. vermiformis and Desmoscaphites erdmanni, 

should be transitional between these genera. Unfortunately, the inner whorls have not been seen and the 

generic assignment of C.? choteauensis is only tentative. 

Desmoscaphites erdmanni gave rise to D. bassleri (Reeside, 1927c, p. 16, pi. 21, figs. 17-21; pi. 22, figs, 8-12) 

of the Telegraph Creek formation by further increasing 

the density of ribbing and developing uniform spacing 

of the ventral ribs. '_

Associated with Clioscaphites novimexicanus and 

Desmoscaphites erdmanni in the latest Colorado beds 

is a small species, Scaphites leei Reeside, which is completely foreign to the native. Western Interior fauna. 

This species is characterized by its stout whorls, swollen 

living chamber, smooth flanks, umbilical and ventrolateral nodes, and simple suture with symmetrically 

bifid first lateral lobe. Scaphites leei marks the first 

appearance in the Interior fauna of a prominent group 

of scaphites (Reeside, 1927c) characterized by S. 

hippocrepis (DeKay) and S. aguilaensis Reeside that 

migrated to America from Europe in Santonian time. 

These species, rare at first, rapidly dominated the fauna 

and replaced the Interior scaphites. Only Desmoscaphites bassleri and an undescribed descendent of 

Clioscaphites platygastrus are known of the native 

stock in Telegraph Creek time, and by Eagle time, all 

the scaphites known are of the S. hippocrepis-S. 

aguilaensis group.

The first lateral lobe of the external suture reveals 

an interesting line of development (fig. 3). In Scaphites 

warreni and S. whitfieldi this lobe is bifid, with each 

branch consisting of a lower, broadly pointed prong 

and a lateral bifid prong. This basic pattern is seen in 

pre-$. warreni species, but in general, it is not as 

perfectly developed and commonly lacks bilateral 

symmetry. The next step in the development of this
GEOGRAPHIC DISTRIBUTION 11

novimexicanus

montanensis:

depress us

preventricosus

nigricqllensis

. Evolution of the trifld first lateral lobe. The vejiter would be to the left.

lobe is shown by S. nigricollensis in which the apicad 

prongs became trifid. The next stage was perfected in 

S. preventricosus. The lateral prongs became asymmetrically bifid, with the lower part of each trifid and 

the upper part smaller and bifid. In general, the lobe 

was still symmetrical, with a large central saddle and 

two smaller "equidimensional lateral saddles. In S. 

depressus and varieties the symmetry was largely lost 

by a slight dwarfing of the ventrad branch of the 

lobe. This was carried to a great extreme in Clio-' 

scaphites montanensis, which had the dorsad branch of 

the lobe much longer than the ventrad branch. The 

dorsad saddle became almost as large as the central 

saddle, and the ventrad saddle was greatly reduced. 

In the overlying C. novimexicanus zone the trifid lobe 

was perfected by the migration of the trifid prong of

the dorsad branch to a central position. The ventrad 

branch was reduced to the size of the dorsad prong and 

became symmetrical with it, having its prongs simplified 

to such an extent that the upper prong was reduced 

from five points to two.

In summary, the scaphites of the Colorado group 

reveal several trends in their development that persisted through many faunal zones. The main line of 

scaphites show, in the Greenhorn and early Carlile, 

trends toward increase in size, decrease in density of 

ribbing, and simplification of suture. Scaphites warreni 

of the basal part of the middle Carlile, marks the 

maximum simplification of the suture, and initiates a 

trend toward dense ribbing. This species shows a 

sudden decrease in size that possibly reflects adverse 

environmental conditions of that time. After that time, 

the trend was toward gradual increase in size and in complexity of suture. The maximum size was attained 

in the zones of Scaphites ventricosus, S. depressus, 

and Clioscaphites montanensis, of the middle and late 

Niobrara, and the greatest complexity of suture was 

reached in Clioscaphites montanensis. After the time 

of C. montanensis, the scaphites decreased in size and 

the suture became simpler. In the late Carlile the 

scaphites tended to become less unrolled in the adult 

stage., and by late Niobrara the whole dorsum of the 

living chamber was in contact with the outer septate 

whorl. This accompanied a reduction in the size of 

the umbilicus and a tendency for the umbilical wall 

of the adult living chamber to.be extended over the 

umbilicus of the septate whorls.

In the late Carlile a split from the main scaphite 

line gave rise to a group of species at first, characterized 

by peculiar, high, sharp ribs, and later by the development of a row of ventrolateral tubercles. These 

species paralleled the main line of scaphites in becoming 

larger, less unrolled, and in developing a suture with 

trifid lobes. However, the suture never reached the 

degree of complexity seen in Clioscaphites montanensis.

A group of tiny species represents another line of 

development beginning -with Scaphites pfaecoquus 

of the basal Carlile. This species, which is very 

closely related to S. larvaeformis, has a nearly normal 

aperture, but the later .species showed progressively 

greater forward extension of the lateral margins of the 

aperture. By early Niobrara . time, conspicuous 

pointed lateral lappets were developed and, by the 

late Niobrara, the suture developed trifid lobes.

GEOGRAPHIC DISTRIBUTION

The occurrence of the scaphites of the Colorado 

group by state and locality is indicated in the insert 

(facing p. 12), and the localities are indicated on figure 4.
12 SCAPHITOID CEPHALOPODS OF THE COLORADO GROUP

FIOURE 4. Index map showing localities of collections from rocks of Colorado age. Numbers refer to th'e table of distribution and to the'detailed description of localities on

pages 13-18.

GEOGRAPHIC DISTRIBUTION

The individual localities are described in the following list.

Localities at which scaphite cephalopods were collected from rocks of the Colorado group

13

No. 

on 

flg. 

4

1

2

3

4

5

0

7

8

9

10

11

12-

13

14

15

10

17

18

10

20

21

22

23

24

XJ.S.O.S. 

Mcsozoic 

locality 

number

7127

7128

7129

(\KK 1 UOU I

7131

7102

7137

7142

9303

9301

8048

20299

21007

8005

20291

20292

20295

21483

11995

11974

2029G 

20298

20297

20289

Collector, year of collection, description of 

locality, and stratigraphic assignment

M. R. Campbell and T. W. Stanton, 1911. About 2.5 miles

west-northwest of Summit, Glacier National Park, Mont.

' Colorado shale.

M. R. Campbell, J. Hoats, and T. W. Stauton, 1911. On southwest slope of Summit Mountain, Glacier National Park, Mont.

Colorado shale.

T. W. Stanton, 1911. Great Northern Railroad cut three-fourths

mile northeast of {Summit, Glacier National Park, Mont.

Colorado shale.

M. 11. Campbell, 1910. Railroad cut 2.5 miles west of Lubec,

Glacier National Park, Mont. Colorado shale.

T. W. Stantou, 1911. East slope of Squaw Mountain north of

Lubec, Glacier National Park, Mont. Colorado shale.

M. R. Campbell and J. Hoats, 1911. Ridge south of North Fork

of Cut Bank Creek, Glacier National Park, Mont. Colorado

shale.

M. R. Campbell, J. Hoats, and T. W. Stantou, 1911. North side

of Two Medicine River, 9 miles south of Browning, in the N WM

sec" 27, 'T. 31 N., R. 11 W., Glacier County, Mont. Colorado

shale.

M. R. Campbell and T. W. Stanton, 1911. South side of Two

Medicine River, in the NWH sec. 26. T. 31 N., R. 11 W.,

Glacier County, Mont. Colorado shale.

L. S. Kompher, 1915. Four miles west of Sunburst, in sec. 9,

T. 30 N., R. 3 W., Toole County, Mont. Colorado shale,

upper part.

L. S. Kempher, 1915.. Four miles west of Sunburst, in sec. 16,

T. 36 N., R. 3 W., Toole County, Mont.' Colorado shale,

near top.

T. W. Stanton, 1912. Nine miles west of Kevin, in sec. 29, T. 35

N., R. 4 W., Toole County, Mont, Colorado shale, near top.

C. E. Erdmann and J. T. Gist, 1944. Five miles northwest of

Kevin, in the NEMNWtf sec. 24, T. 35 N., R. 4 W., Toole

County, Mont. Colorado shale, 101 feet below top.

C. E. Erdmann, R. W. Imlay, and J. B. Reeside, Jr.,. 1944. Five

miles northwest of Kevin, in the NE. corner NW14 sec. 24,

T. 35 N., R. 4 W., Toolo County, Mont. Colorado shale, 23

feet below top.

Eugene Stebinger, 1913. Five miles northwest of Kevin, in the

NWfci sec. 24, T. 35 N., R. 4 W., Toole County, Mont. Colorado

shale, upper part.

C. E. Erdmaim and J. T. Gist, 1944. Four miles north of Kevin,

in the SWM sec. 3, T. 35 N., R. 3 W., Toole County, Mont.

Colorado shale, 379 to 381 feet below top.

0. E. Erdmaim and J. T. Gist, 1944. Same locality as 20291..

Colorado shale, 381 to 388 feet below top.

C. E. Erdmann and J. T. Gist, 1944. Same locality as 20291.

Colorado shale, 304 feet below top. . B. R. Alto, W. A. Cobban, and C. T. Moore, 1949. Five miles

northwest of Kevin, in the SE^NEJ^ sec. 4, T. 35 N., R. 3 W.,

Toole County, Mont. Colorado sualo, in ferruginous concretions 306 to 392 feet below top.

A. J. Collier, 1923. Three miles northwest of Kevin, in sec. 17,

T. 35 N., R. V 3 W., Toolo County, Mont. Colorado shale, 20

foot below top.

A. J . Collier, 1923.. Three miles north of Kevin, in the NEK sec.

15, T. 35 N., R. 3 AV., Toole County, Mont. Colorado shale,

500 to 580 feet below top.

C. E. Erdmann and J. T. Gist, 1944. Three miles north of Kevin, 

in the SWJiNW&NE&sec. 15, T. 35N., R. 3 W., Toole County, 

Mont. Colorado shale, 513 to 517 feet below top. 

C. E. Erdmann and J. T. Gist, 1944. Same locality as 20296.

Colorado shale, 627 to 531 feet below top.

C. E . Erdmann and J. T. Gist, 1944. Three miles north of Kevin,

in the NWJi sec. 15, T. 35 N., R. 3 W., Toole County, Mont.

Colorado shale, 528 to 532 feet below top.

C. E. Erdmann and J. T. Gist, 1944. Three miles north of Kevin,

in the SW^NE JiN WJi sec. 15, T. 35 N., R. 3 W., Toole County,

Mont. Colorado shale, about .000 feet below top.

No. 

on 

flg. 

4

25

20

27

28

29

30

31

32

33

34

35

36

37

38

39

40

41

42

43

44

45

46

47

U.S.G.S. 

Mesozoic 

locality 

number

20911

21429

21807

22130

11987

21419

11989

21412

21425

21421

21422

11979

22166

22149

22161

22164

9853

9856

9890

4023

11971

 21806

21372

Collector, year of collection, description of 

locality, and stratigraphic assignment

C. E. Erdmann, 1947. Five miles north-northwest oJ Oilmont,

in the NWJ£NW^NW}£ sec. 12, T. 35 N ., R. 2 W., Toole

County, Mont. Colorado shale, pebbly sandstone 651 feet

below top.

W. A. Cobbau, 1943. One mile west of Oilmont, In the NW#

NWJ^sec. 3,T.34N.,R.2W.,TooloCounty, Mont. Colorado

shale, in ferruginous concretions about 800 feet below top of

Colorado.

W. A. Cobban, 1949. Ten miles east of Oilmont 'in the SEJtfSEJi

SEJisec. 32, T. 35 N., R. 1 E., Toole County, Mont. Colorado

shale, about 675- feet below top.

M. E. Porter, 1948. About 2 miles north of Ethridge, Toole County, Mont. Colorado shale near top. (

A. J. Collier, 1923. Three miles northwest of Shelby, in sec. 8,

T. 32 N., R. 2 W., Toole County, Mont.

W. A. Cobban, 1948. Eight miles wes t of Shelby, at head of

ravine 3 miles north of Marias River, Jn the NEJ£ sec. 31, T. 32

N., R. 3 W., Toole County, Mont. Colorado shale, 10 feet

below top. 

A. J. Collier, 1923. North side o « Manias River, sec. 3, T. 31 N.,

R. 4 W., Toole County, Mont. Colorado shale.

B. R. Alto and K. Holmes, 1948. About 11.5 miles southwest of

Shelby, in the SWJiSWJi sec. 14, T. 31 N., R. 4 W., Pondera

County, Mout. Colorado shale, about 250 feet below top.

W. A. Cobban, 1940. East bank of Marias River, 11 miles southwest of Shelby, in the W^NEJiSEJ^ sec. 14, T. 31 N., R. 4 W.,

Toole County, Mont. Colorado shale, 234 to 252 feet below top.

W. A. Cobban, 1935. North bank of Marias River, 5.5 miles south

of Shelby, in the NEJi sec. 20, T. 31 N., R. 2 W., Toole County,

Mont. Colorado shale, 617 to 634 feet below top.

W. A. Cobban, .1935. Same locality as 21421. Colorado shale,

514 to 525 feet below top.

A. C. Collier, 1923. One mile below railroad bridge across Marias

River, in sec. 4, T..30 N., R. 1 W., Toole County, Mpnt. Colo-

 rado shale.

K. .H. Holmes, 1949. Nine miles southwest of Devon, in the

SEJiSWJi sec. 16, T. 30 N., R. 1 E., Toole County, Mont.

Colorado shale, 408 feet below top.

K. H. Holmes, 1949. Eleven miles south of Devon, in the SEJ£

SWJ^sec. 34, T. 30 N., R. 2 E., Toole County, Mont. Colorado

shale, 165 feet below top.

K. H. Holmes, 1949. Marias River, 9 miles south of Devon, in

the NEJ^SWJi sec. 22. T. 30 N., R. 2 E., Toole County, Mont.

Colorado shale, 330 feet below top.

K. H. Holmes, 1949. Eight miles south-southwest of Devon, in

the NWJ4SWJ4 sec. 18, T. 30 N., R. 2 E., Toolo County, Mont.

Colorado shale, 484 feet below top.

M. I. Goldman, 1910. Sheep Creek, in sec. 34, T. 28 N., R. 8

W., Pondera County, Mont. Colorado shale.

M. I. Goldman and E. Stebinger, 1910. Southeast slope of Antelope Butte, in sec. 28, T. 20 N., R. 8 W., Teton County, Mont.

Colorado Shale.

Eugene Stebinger, 1910. On Willow Creek, in the NWJ^ sec. 19.

T. 24 N., R. 7 W., Teton County, Mont. Colorado shale, near

top.

W. R. Calvert, 1906. About half a mile northeast of Choteau, in

sec. 19, T. 24 N., R. 4 W., Teton County, Mont. Colorado

shale, upper part.

A. J. Collier, 1923. North side of Teton River above Dent bridge, 

in sec. 34, T. 25 N., R. 3 W., Teton County, Mont. Colorado 

shale, about 500 feet below top.

W. A. Cobban and C. T. Moore, 1949. Two miles southeast of

Power, in the WJ^ sec. 34, T. 23 N., R. 1 W., Teton County,

Mont. Colorado shale, about 900 feet above base.

W. A. Cobban and R. W. Imlay, 1940. Two miles north of Fort

Shaw, in the &M sees. 35 and 30, T. 21 N., R. 2 W., Cascade

County, Mont. Colorado shale, 184 to 208 feet above top of

calcareous shale of Greenhorn age.

939551 51-
14 SCAPHITOID CEPHALOPODS OF THE COLORADO GROUP

Localities at which scaphite cephalopods were collected from rocks of the Colorado group Continued

No. 

on 

flg. 

4

48

49

50

51

52

53

54

55

56

57

58

59

60 '

61

62

63

64

65

66

67

68

69

70

71

' 72

73

74

75

76

U.S.G.S. 

Mesozoic 

locality 

number

21373

21375

3956

16201

1400

152

' - 1403

--._.

154

1404

8968

2852

1407

2839

2847a

7904

21399

21401

21402

21403

8828

2894

2895

2896

4655

4656

4588

1663

.....

Collector, year of collection, description of 

locality, and stratigraphic assignment

W. A. Cobban, 1942. Same locality as 21372. Colorado shale,

202 to 207 feet above calcareous shale of Greenhorn age.

W. A. Cobban, 1942. Same locality as 21372. Colorado. shale,

238 to 255 feet above calcareous shale of Greenhorn age.

C. A. Fisher, 1906. Six miles northwest of Geyser, Judith Basin

County, Mont. Colorado shale.

C. B. Hunt, 1932. T. 26 N-., R. 7 E., Chouteau County, Mont.

Colorado shale, 270 feet below base of Virgelle sandstone.

T. W. Stanton, 1894. Fort. Benton, Mont. Colorado shale.

J. B. Marcou, 1883. Fort Benton, Mont. Colorado shale.

T. W. Stanton and W. H. Weed, 1894. Missouri River, about 10

miles below Fort Benton. Colorado shale.

John Pearsall, 1862. Chippewa Point, on the Missouri River 20

miles [presumably river miles] below Fort Benton, Mont.

Colorado shale, upper part.

J. B. Marcou, 1883. Missouri River 3 miles below mouth of

Marias River. Colorado shale.

T. W. Stanton and W. H. Weed, 1894. Missouri River 4 or 5

miles below mouth of Marias River, Mont. Colorado shale,

upper part. .

E. R. Lloyd, W. T. Thorn, Jr., and W. B. Wilson, 1914. One

milejsouth of Virgelle, in the NEJi sec. 24, T. 26 N., R. 11 E.

Chouteau County, Mont. Colorado shale.

J. B. Hatcher, and T. W. Stanton, 1903. Missouri River near

Eagle Butte, Chouteau County, Mont. Colorado shale.

T. W. Stanton and W. H. Weed, 1894. On Missouri River 5 or 6

miles below mouth of Arrow Creek. Fergus County, Mont.

Colorado shale, upper part.

J. B. Hatcher and T. W. Stanton, 1903. Thirteen miles above

mouth of Cow Creek, Blaine County, Mont. Colorado shale,

upper part. '

J. B. Hatcher, and T. W. Stanton, 1903. Thirteen miles above

mouth of Cow Creek [probably the WJ^ sec. 4, T. 25 N., R. 21 E .,

Blaine County], Mont. Colorado shale.

C. F. Bowen, 1912. Southwest flank of West dome of Cat Creek

anticline, in see. 17, T. 15 N., R. 29 E., Petroleum County,

Mont. Colorado shale, near top.

W. A. Cobban, 1948. Half a mile west of bridge over Musselshell

River near Mosby, in the SEJ£ sec. W, T. 14 N., R. 30 E.,

Petroleum County, Mont. Colorado shale, in ferruginous

concretions, 99 to 115 feet above top of Mosby sandstone

member.

W. A. Cobban, 1948. Three miles east of Mosby, in the SWJ£

sec. 8, T. 14 N., R. 31 E., Garfleld County, Mont. Colorado

shale, 5 feet above so-called Sage Hen limestone member.

W. A. Cobban, 1948. Three miles east of Mosby, in the NJ£

sec. 8, T. 14 N., R. 31 E., Garfleld County, Mont. Colorado

shale, 300 feet below top of calcareous shale of Niobrara age.

W. A. Cobban, 1948. Same locality as 21402. Colorado shale,

251 to 280 feet below top of calcareous shale of Niobrara age.

C. E. Lesher, 1914. Sec. 19, T. 9 N., R. 22 E., Golden Valley

County, Mont. Colorado shale.

M. S. Farr, J. B. Hatcher, A. C. Silberliug, and T. W. Stanton,

1903. Near Crawford's Ranch, in the NWJ£ T. 6 N., R. 16 E.,

Wheatland County, Mont. Colorado shale, upper part.

M. S. Farr. J. B. Hatcher, A. C. Silberling, and T. W. Stanton,

1903. Near Crawford's Rranch on Mud Creek, Wheatland

County, Mont. Colorado_shale, near top.

M. S. Farr, J. B. Hatcher, A. C. Silberling, and T. W. Stanton,

1903. Mud Creek about one mile northeast of Crawford's

Ranch, Wheatland County, Mont. Colorado shale.

R. W. Stone, 1907. East bank of American Fork, in sec. 23, T. 7

N., 15- E., Wheatland County, Mont. Colorado shale.

R. W. Stone, 1907. Ten miles south of Harlowton, in sec. 12,

T. 6 N., R. 15 E., Wheatland County, Mont. Colorado shale.

R. W. Stone, 1907. Big Elk Creek near bridge, in the NEJi

sec. 36, T. 7 N., R. 13 E., Wheatland County, Mont. Colorado shale.

A. C. Peale, 1891. Opposite Jefferson Canyon. [Probably about

5 miles west of Sappington, Madison County, Mont.] Colorado

shale.

F. V. Hayden, 1871. Cinnabar Mountain, near Gardiner, Park

County, Mont. Colorado shale, upper part.

No. 

on 

flg. 

4

77

78

79

80

81

' 82

83

84

'85

86

87'

88

89

90

91

92

93

. 94

95

96

97

98

99

100

101

102

U.S.G.S. 

Mesozoic 

locality 

number

22131

5608

9642

' 5230

5235

9420

9632

9651

5051

10897

20954

21805

20952

20953

20946

20935

20937

20938

20939

10888

10912

10909

12632

12637

21796

21181

Collector, year of collection, description of 

locality, and stratigraphic assignment

W. A. Cobban, 1937. Cinnabar Mountain, 4.5 miles westnorthwest of Gardiner, Park County, Mont. Colorado shale,

near top.

W. R. Calvert and T. W. Stanton, 1908. North side of Boulder

Creek near old McLeod P. O., Sweet Grass County, Mont.

Colorado shale, near top.

C. J. Hares, 1916. South bank of Yellowstone River, sec. 6, T.

3 S., R. 23 E., Carbon County, Mont. Colorado shale.

T. E. Williard, 1907. South side .of Yellowstone River, 1.5 miles

east of Billings, Yellowstone County, Mont. Colorado shale.

T. E. Williard, 1907. South side of Yellowstone River, 1.5 miles

southeast of Billings, Yellowstone County, Mont. Colorado

shale.

C. J. Hares, 1915. Billings, Mont. Colorado shale, upper part.

 C. J. Hares, 1916. Five miles southeast of Bridger, in sec. 15,

T. 7 S., R. 23 E., Carbon County, Mont. Colorado shale.

.C. J. Hares, 1916. Southeast of Bri'dger, in T. 7 S., R. 24 E.,

Carbon County, Mont. Colorado shale.

E. F. Schramm, 1907. Southwest of Bowler, in T. 8 S., R. 24 E.,

Carbon County, Mont, Colorado shale.

W. T. Thorn, Jr., 1921. Thirteen miles-west of Hardin, in the

NEJi sec. 4, T. 2 S.,.R. 31 E., Big Horn County, Mont. Cody

shale, Niobrara member. 

Paul Richards, 1947. North side of Woody Creek, 16 miles southwest of Hardin, in center of sec. 4, T. 3 S., R. 31 E., Big Horn

County, Mont. Cody shale, Carlile member.

W. A. Cobban, 1947. Cut on Two Leggin Creek, in T. 2 S., R.

32 E., Big Horn County, Mont. Cody shale, Carlile member . W. A. Cobban, 1947. East bank of Bighorn River 2 miles southeast of Hardin, in the EJ^ sec. 36, T. 1 S., R. 34 E., Big Horn

County, Mont. Cody shale, 154 to 160 feet below top of Nio-.

brara member.

W. A. Cobban,' 1947. East bank of Bighorn River 1 mile southeast of Hardin, in the NEJ^NEJi sec. 25, T. 1 S., R. 34 E., .Big

 Horn County, Mont. Cody shale, upper 32 feet of Niobrara

member. - W. A. Cobban, 1947. Seven miles south of Hardin, in the SWJi

sec. 26, T. 2 S., R. 33 E., Big Horn County, Mont. Cody shale,

280 feet above the top of the Greenhorn calcareous member.

W. A. .Cobban,. 1947. East flank of Soap Creek dome, in the

NWJ^SWJi sec. 36, T. 6 S., R. 32 E., Big Horn County, Mont.

Cody shale, 58 feet below top of Greenhorn calcareous member:

W. A. Cobban, 1947. East flank of Soap Creek dome, in the

- NWJiSWJ^ sec. 36, T. 6 S., R. 32 E., Big Horn County, Mont.

Cody shale, 152 to 164 feet above top of Greenhorn calcareous

member. .

W.-A. Cobban, 1947. Same locality as 20937. Cody shale, 165

to 180 feet above top of Greenhorn calcareous member.

W. A. Cobban, 1947. East flank of Soap Creek dome, in the

NWJ^SWJi sec. 36, T. 6 S., R. 32 E., Big Horn County, Mont.

Cody shale, ISl.feet above top of Greenhorn calcareous member.

G. F. Moulton, 1921. Seventeen miles southwest of Lodge Grass,

near center of sec. 21, T. 7 S., R. 33 E., Big Horn County, Mont.

Cody shale, Niobrara member.

G. F. Moulton and W. T. Thorn, Jr., 1921. Northeast flank of

Rotten Grass dome, in sec. 21, T. 7 S., R. 33 E., Big Horn

County, Mont. Cody shale, Carlile member.

G: F. Moulton, 1921. Seven miles west of Wyola, at north bend

of dry creek entering Lodge Grass Creek from the west above

Miller's Ranch, near east quarter corner of sec. 16, T. 8 S., R.

34 E., Big Horn County, Mont. Cody shale, near middle.

W. W. Rubey, 1924. Sec. 4, T. 8 S., R. 57 E., Carter County '

Mont. Carlile shale, Sage Breaks member, about middle.

Wj W. Rubey, 1924. Fourteen miles northwest of Alzada, in the

NJ/6 sec. 5, T. 8 S., R. 58 E., Carter County, Mont. Carlile

shale, 20 feet above base of Sage Breaks member.

W. A. Cobban, 1941. Northeast side of Five Mile Creek valley.

in the WJ£ sec. 14, T. 9 S., R. 60 E., Carter County, Mont.

Greenhorn formation, about 10 feet below top.

W. A. Cobban, 1947. Five miles north of Belle Fourche, in the

NEJiNW^NWJi sec. 14 and NW^NE^NEM sec. 16, T. 9

N., R. 2 E., Butte County, S. Dak. Carlile shale, light-gray

limestone concretions 12 feet above base. 
GEOGRAPHIC DISTRIBUTION 

Localities at which scaphite cephalopods were collected from rocks of the Colorado group Continued

15

No. 

on 

fig. 

4

103

104

105

100

107

108

109

110

111

112

H3

114

ll.r>

110

117

113

111)

120

121

122

123

124

125

120

127

128

129

130

u.s.a.s.

Mcsozoic 

locality 

number

21182

21183

21184

21180

2118ft

21187

21188

21189

21190

21194

21195

21198

21199

12734

21428

12176

21705

21 953

18872

12042

10383

10382

.....

13010

10281

12091

.11190

21792

Collector, year of collection, description of 

locality, and stratigraphic assignment

W. A. Cobban. 1947. Five miles north of Belle Fourche. in the

SWMSEJiSWJi sec. 11, T. 9 N., R. 2 E., Butte County, S.

Dak. Curlilo shale, in ferruginous concretions 57 to 81 feet above

base.

W. A. Cobban, 1947. Same locality as 21182. Carlile shale, 58

to 05 feet above base.

W. A. Cobban, 1947. Same locality as 21182. Carlile shale, 05

feet above base.

W. A. Cobban, 1947. Same locality as 21182. Carlile shale, 06

to 78 feet above base.

W. A. Cobban, 1947. Same locality as 21182. Carlile shale, 81

feet above base.

W. A. Cobban, 1947. Five miles north of Belle Fourche, in the

SW&SEJ<fSWJ£ sec. 11, T. 9 N., R. 2 E., Butte County, S.

Dak. Carlilo shale, from large calcareous concretions 14.5 feet

above base of Turner sandy member.

W. A. Cobban, 1947. Same locality as 21187. Carlile shale, from

calcareous concretions 36 feet above base of Turner sandy

morn her.

W. A. Cobban, 1947. Six miles north of Belle Fourche, in the

Ny2 sec. 10, T. 9 N., R. 2 E., Butte County, S. Dak. Carlile .

shale, 104 feet above base.

W. A. Cobban, 1947. Same locality as 21189. Carlile shale, 194

to 202 feet above base.

W. A. Cobban, 1947. Same locality as 21189. Carlile shale, 251

to 264 feet above base.

W. A. Cobban, 1947. Six miles north of Belle Fourche, in the

NEJrfNEJiNWK sec. 10, T. 9 N., R. 2 E., Butte County, S.

Dak. Carlilo shale, 272 to 274 feet above base.

W. A. Cobban, 1947. Same locality as 21195. Carlile shale, 293

feet above base.

W. A. Cobban, 1947. Same locality as 21195. Carlile shale, 333

to 336 feet above base.

W. W. Ruboy, 1924. Five miles north of Belle Fourche, S. Dak.

Carlilo shale, lower part.

W. A. Cobban, 1940. Three miles northeast of Fruitdale, in

center of sec. 33, T. 9 N., R. 4 E., Butte County, S. Dak. Carlile

shale, about 00-70 feet above base.

Mrs. C. J. Haas, 1923. Near Whitewood, Lawrence County,

S. Dak. Carlilo shale.

W. A. Cobban, 1948. Nine miles south-southeast of Rapid City,

In the NEJi sec. 22, T. 1 S., R. 8 W., Pennington County, S.

Dak. Sage Breaks member of Carlile shale, 42 to 46 feet above

base.

W. A. Cobban, 1946. Nine miles south-southeast of Rapid City,

in the NWK sec. 21, T. 1 S., R. 8 E., Pennington County, S.

Dak. Carlilo shale, near base.

N. H. Darton, 1898. Two miles southeast of Fairburn, Custer

County/S. Dak. Carlile shale, lower part.

J. B. Recside, Jr. and W. W. Rubey, 1924. Two miles south of

Fairburn, in sec. 31, T. 4 S., R. 8 E., Custer County, S. Dak.

Carlilo shale, calcareous concretions 90 feet below top of lower

member.

T. W. Stanton, 1920. Half a mile southwest of Buffalo Gap,

Custor County, S. Dak. Carlile shale, Turner sandy member.

T. W. Stanton, 1920. About 5 miles southeast of Hot Springs

Fall River County, S. Dak. Carlile shale, near base.

F. V. Haydcn, 1857. Southern base of Black Hills, S. Dak.

Carlilo shale.

W. W. Ruboy, 1920. Five miles south of Eclgemont, in the NW>£

soc. 30, T. 9 S., R. 3 E., Fall River County, S. Dak. Carlile

shale, sandstone 43 feet above shark-tooth conglomerate.

E. T. Hancock, 1919. Mule Creek oil field, in sec. 18, T. 39 N.,

11. 60 W., Niobrara County, Wyo. Carlile shale, in a sandstone

200 foot above base.

W. W. Ruboy, 1924. One mile south of Newcastle, in sec. 2, T.

44 N., R. 61 W., Weston County, Wyo. Carlile shale, 20 feet

above shark-tooth conglomerate of Turner sandy member.

C. R. Longwell and W. W. Ruboy, 1922. About 2.5 miles south

of Newcastle, Weston County, Wyo. Carlile shale, near base.

W. A. Cobban, 1948, One mile west of Newcastle, Weston

County, Wyo. Carlilo shale, light-gray limestone concretions

62. to 70 feet above base.

No. 

on 

fig. 

4

131

132

133

134

135

136

137

138

139

140

141

142

143

144

145

146

147

148

149

150

151

152

153

154

155

156

157

158

U.S.O.S. 

Mesozoic 

locality 

number

10334

11200

10410

8644

12630

21424

21591

21798

17933

17954

17955

17956

17957

17958

17959

18152

18156

18160

17942

17952

17928

4991

4960

7369

3079

.....

---..

17175

Collector, year of collection, description of 

locality, and stratigraphic assignment

Mrs. W. O. George, 1920. Near Pedro, Weston County, Wyo.

Carlile shale.

W. W. Rubey, 1922. About a mile east of Pedro, Wyo. Carlile

shale.

A. J.' Collier, K. C. Heald, and M. G. Gulley, 1920. Railroad cut

in sec. 3, T. 48 N., R. 66 W., Weston County, Wyo. Carlile

shale.

V. H. Barnett, 1913. About 15 miles north of Moorcroft, in the

NE^SEM sec. 33, T. 52 N., R. 67 W., Crook County, Wyo.

Carlile shale.

W. W. Rubey, 1924. Three miles 'north of Oshoto, in the NEK

sec. 32, T. 54 N., R. 67 W., Crook County, Wyo. Carlile shale,

middle of Turner sandy member.

M. M. Knechtel, 1947. Eleven miles southeast of Rockypoint,

in sec. 30, T. 56 N. R. 67 W., Crook County, Wyo. Carlile shale,

Turner sandy member.

W. A. Cobban, 1948. Southwest flank of Bull Creek anticline, in

the NEJi sec. 15, T. 57 N., R. 62 W., Crook County, Wyo.

Carlile shale, light-gray limestone concretions near base.

W. A. Cobban, 1941. Northeast side of Crow Creek valley, in the

EM sec. 9, T. 57 N., R. 61 W., Crook County, Wyo. Ferruginous concretions 76 to 101 feet below top of the Greenhorn

formation.

R. P. Bryson and W. G. Pierce, 1938. Line Creek, in the

NWKNWK sec. 35, T. 58 N., R. 103 W., Park County, Wyo.

Cody shale.

W. G. Pierce and J. B. Reeside, Jr., 1938. Line Creek, in the

SEMSWJi sec. 26, T. 58 N,, R. 103 W., Pork County, Wyo.

Cody shale, 690 to 720 feet above base.

W. G. Pierce and J. B. Reeside, Jr., 1938. In the SEJ-iSW^

sec. 26, T. 58 N., R. 103 W., Park County, Wyo. Oody shale,

630 feet above base.

W. G. Pierce and J. B. Reeside, Jr., 1938. In the SWMSWJi

sec. 26, T. 58 N., R. 103 W., Park County, Wyo. Cody shale,

590 feet above base.

W. G. Pierce and J. B. Reeside, Jr., 1938. Line Creek, in the

SEMSWK sec. 26, T. 58 N., -R. 103 W., Park County, Wyo.

Cody shale, 760 to 810 feet above base.

W. G. Pierce, 1938. Line Creek, in the SEJ^SWK sec. 26, T. 58

N..T.103W., Park County, Wyo. Codyshale, 1,110 feet above

base.

W. G. Pierce, 1938. Line Creek, in the NW^NWK sec. 35, T.

58 N., R. 103 W., Prk County, Wyo. Cody shale, about 700

feet above base.

W. G. Pierce,' 1938. Line Creek, in the SE^SWJi sec. 26, T.

58 N., R. 103 W., Park County, Wyo. Cody shale, 1,215 feet

above base.

W. G. Pierce, 1938. In the SW^SWK sec. 26, T. 58 N., R. 103

W., Park County, Wyo. Cody shale, 620 feet above base.

W. G. Pierce, 1938. In the SWJ4SWJ4 sec. 26, T. 58 N., R. 103

W., Park County, Wyo. Cody shale, 370 feet above base.

W. G. Pierce, 1938. South of Bennett Creek, in the SWKSEK

sec. 10, T. 57 N., R. 103 W., Park County, Wyo. Cody shale,

375 feet above base.

W. G. Pierce and J. B. Reeside, Jr., 1938. South of Bennett

Creek, in the SWJ^SEM sec. 10, T..57 N., R. 103 W., Park

County, Wyo. Cody shale, 375 feet above base.

W. G. Pierce, 1937. In the SW^NWK sec. 23, T. 55 N., R. 103

W., Park County, Wyo. Cody shale about middle.

T. E. Williard, 1907. South side of Shoshone River about 2 miles

east of Cody bridge, Park County, Wyo. Cody shale.

C. A. Fisher and E. G. Woodruff, 1907. Shoshone River, two

miles east of Cody, Wyo. Cody shale.

D. F. Hewett, 1911. South side of Shoshone River 3 miles northeast of Cody, Park County, Wyo. Cody shale.

C. A. Fisher, 1904. Near Cody, Wyoming. Cody shale.

Edwin Binney, Jr., 1924. Oregon Basin, in sec. 6, T. 51 N., R.

100 W., Park County, Wyo. Cody shale, 600 feet above base.

Edwin Binney, Jr., 1924. Oregon Basin, in sec. 6, T. 51 N., R.

100 W., Park County, Wyo. Cody shale, 800 feet above base.

W. G. Pierce, 1935. West flank of Fourbear anticline, half a mile

northwest of Palette Ranch No. 2, 9.5 miles west of Pitchfork,

in sec. 18, T. 48 N., R. 103 W., Park County, Wyo. Cody shale.
16 SCAPHITOID CEPHALOPODS OF THE COLORADO GROUP

Localities at which scaphite cephalopods were collected from rocks of the Colorado group Continued

No. 

on 

fig. 

4

159

160

161

162

163

164

165

166

167

168

169

170

171

172

173

174

175

176

177

178

179

180

181

182

183

184

185

186

U.S.G.S. 

Mesozoio 

locality 

number

17176

17168

17164

17110

17115

10422

10421

8915

4538

4958

8278

. 9615

4539

9770

4540

9675

9669

20701

21109

21173

21110

21179

17301

17302

17315

6286

19532

20920

Collector, year of collection, description of 

locality, and stratigraphic assignment

D. A. Andrews and W. Q. Pierce, 1935. Eight miles west-northwest of Pitchfork, in the NW}£ sec. 21,. T. 48 N., R. 103 W.,

Park County, Wyo. Cody shale, 200 feet above base,

D. A. Andrews, 1935. South side of Spring Creek, near Meeteetse,

Wyo. Cody shale.

W. G. Pierce, 1935. Pitchfork anticline, in the SEMSEJi sec.

2, T. 48 N., R. 102 W., Park County, Wyo. Cody shale, 1,400

feet above base.

W. G. Pierce, 1935. In the NEJ£NWJ£ sec. 24, T. 48 N., R. 102

W., Park County, Wyo. Cody shale.

W. G. Pierce, 1935. In the NEJi sec. 10, T. 46 N'., R. 101 W., Park

 County, Wyo. Cody shale.

M. G. Gulley and K. C. Heald, 1920. South of Kirby Creek,

in the NEJi sec. 20, T. 43 N., R. 92 W., Hot Springs County,

Wyo. Cody 'shale. . M. G. Gulley and K. C. Heald, 1920. South Branch of Kirby

Creek, about 15 miles east of Lucerne, in sec. 22, T. 43 N., R.

92 W., Hot Springs County, Wyo. Cody shale.

W. P. Woodring, 1914. Nine miles northwest of Nowood, in the

NWJ<NE>i sec. 30, T. 43 N., R. 89 W., Washakie County, Wyo.

Cody shale.

M. A. Pishel, 1907. Four miles southeast of Greybull, in the

NWJ^SWJi sec. 25, T. 52 N., R. 93 W., Big Horn County, Wyo.

Cody shale.

M. A. Pishel, 1907. Four miles northeast of Basin, in the

SWMNE Ji sec. 30, T. 52 N., R. 92 W., Big Horn County, Wyo.

Cody shale.

J. Henderson, 1913. Twelve miles east of Basin, Big Horn County,

Wyo. Cody shale.

C. J. Hares, 1916. Garland anticline, one mile west of Byron, in

sec. 33, T. 56 N., R. 97 W., Big Horn County, Wyo. Cody

shale.

C. W. Washburne, 1907. Garland coal field, Park County, Wyo.

Cody shale.

C. J. Hares, 1916. Eight miles southeast of Lovell, Big Horn

County, Wyo. Cody -shale, lower part.

H. P. Little, 1907. Two miles east of Cowley, Big Horn County,

Wyo. Cody shale.

C. J. Hares, 1916. Southeast of Frannie, in sec. 23, T. 57 N., R.

97 W:, Big Horn County, Wyo. Cody shale.

C. J. Hares, 1916. About 1.5 miles south of Frannie, in sec. 24,

T. 58 N., R. 98 W., Park County, Wyo. Cody shale.

J. D. Love, 1945. Gros Ventre area. Teton County, Wyo.

Frontier formation.

H. R. Bergquist, D. C. Duncan; R. K. Hose, and J. D. Love,

1947. In the NEJiNW}< sec. 20, T. 42 N., R. 112 W:, Teton

County, Wyo. Cody shale, 500 feet above base.

D. C. Duncan, R. K. Hose, and J. D. Love," 1947. Same locality

as 21109. Cody shale, sandstone unit 607 to 614 feet above base.

H. R. Bergquist, 1947. One mile northwest of Upper Slide Lake,

in the NW^NEH sec. 19, T. 42 N., R. 112 W., Teton County,

Wyo. Cody shale, 1,283 feet above base.

H. R. Berquist, D. C. Duncan, R. K. Hose, and 3. D. Love, 1947.

North side of bend on Bacon Creek north of Bar Y Creek, in

the NEJiNEJi sec. 22, T. 41 N., T. lll.W., Teton County,

Wyo. Frontier formation, 180 feet below top.

W. W. Rubey, 1936. South Piney Creek, in the NEJ^NW^

sec. 15, T. 29 N., R. 115 W., Sublette County, Wyo. Frontier

formation.

W. W. Rubey, 1936. In the NW^ sec. 22, T. 29 N., R. 115 W.,

Sublette County, Wyo. Frontier formation.

W. W. Rubey, 1936. Afton quadrangle, in the NW^NW}^ sec.

9, T. 26 N., R. 113 W., Lincoln County, Wyo. Hilliard shale.

Robert Forrester, 1909. Glencoe, Lincoln County, Wyo. Frontier formation, just above Kemmerer coal bed.

J. D. Love, 1944. East Fork of Sheep Creek, 35 miles north of

Riverton, in sec. 15, T. 6 N., R. 2 E., Fremont County, Wyo.

Frontier formation, top sandstone unit.

H. H. R. Sharkey, 1945. Bargee area, in the NEJ^NE^ sec. 27,

T. 7 N., R. 1 W., Fremont County, Wyo. Cody shale, about

1,000 feet above base.

No. 

on 

fig. 

4

187

188

189

-

190

191

192

. 193

194

195

196

197

198

199

200

201

202

203

204

205

206

207

208

209

210

U.S.G.S. 

Mesozoic 

locality 

number

20921

21751

21748

10032

10033

21093

 21087

20611

20612

20610

21083a

20614

20773

21547

21548

19542

21099

21100

21549

6011

6012

14308

14310

18945

Collector, year of collection, description of 

locality, and stratigraphic assignment

' H. H. R. Sharkey and M. D. Williams, 1945. Five miles southwest of Bargee, in center of sec. 5, T. 6 N., R. 1 W., Fremont

County, Wyo. Cody shale, in conspicuous rusty sandstone 50

to 75 feet above top of Frontier.

W. R. Keefer, J. D. Love, J. B. Reeside, Jr., and M. L. Troyer,

1949. Northeast flank of Maverick Springs anticline, in the

NEMNE}< sec. 28, T. 6 N., R. 1 W., Teton County, Wyo.

Cody shale, 1,508 feet above base.

J. D. Love and G. N. Pipiringos, 1949. Near Horse Creek, 10

miles north of Dubois, in the SEJ^SWJiSEJi sec. 23, T. 43 N.,

R. 107 W., Fremont County, Wyo. Cody shale, about 1,500

feet above base.

C. J. Hares, 1917. Pilot Butte oil field, in sec. 28, T. 3 N., R. 1

W., Fremont County, Wyo. Cody shale.

C. J. Hares, 1917. Pilot Butte oil field, sec. 34, T. 3 N., R. 1 W.,

Fremont County, Wyo. Cody shale.

G. N. Pipiringos, 1948. Twelve miles northwest of Fort Washakie in the SWJ<NEJ£SWJi sec. 21, T..2 N., R. 2 W., Fremont County, Wyo. Frontier formation, 140 to 190 feet below

top.

G. N. Pipiringos, R. M. Thompson, Max Troyer, and V. White,

1948. Sage Creek anticline, in the SEJi sec. 30, T. 2 N., R. 1

W., Fremont County, Wyo. Frontier formation, upper part.

J. D. Love and J. B. Reeside, Jr., 1944. Same locality as 21087.

Frontier formation, near top.

J. D. Love and J. B. Reeside, Jr., 1944. Same locality as 21087.

Frontier formation, upper part.

J. D. Love and J. B. Reeside, Jr., 1944. Norkok Creek, Fremont

County, Wyo. Frontier formation, near top.

G. N. Pipiringos and R. M. Thompson, 1948. Sage Creek anticline, in the NWJ£ sec. 20, T. 2 N., R. 1 W., Fremont County,

Wyo. Frontier formation, at top.

J. D. Love, 1944. Sage Creek, in the NEJ^SEJiNEJi sec. 18, T.

1 S., R. 1 E.,- Fremont County, Wyo. Frontier formation, near

top.

J. D. Love, 1944. Sage Creek, in sec. 18, T. 1 S., R. 1 E., Fremont County, Wyo. Frontier formation, at top.

J. D. Love, J. B. Reeside, Jr., R. M. Thompson, and M. L.

Troyer, 1949. Eight miles north of Lander, in the NEJ^SWM

sec. 25, T. 1 S., R. 1 E., Fremont County, Wyo. Cody shale,

450 to 574 feet above base.

J. D. Love, J. B. Reeside, Jr.,. R. M. Thompson, and M. L.

Troyer, 1949. Ray Lake, 8 miles north of Lander, in the SWH

NEJi sec. 25, T. 1 S., R. 1 E., Fremont County, Wyo. Cody

shale, 574 to 774 feet above base.

J. D. Love, 1944. Ray Lake, first low ridge on west side, 8 miles

north of Lander, Wyo. Frontier formation.

Max Troyer, 1948. In blufi half a mile north of old Fort Washakie

road, 1 mile north and northwest Of bridge over North Fork, in

the NWKSWJ<SEJi sec. 10, T. 2 S., R. 1 E., Fremont County,

Wyo. Cody shale, about 3,000 feet above base.

Max Troyer, 1948. One-eighth mile- northeast of bridge over

North Fork on 2nd Street Road, 4 miles north of Lander, in the

. NEMSWJiSEJ^ sec. -14, T. 2 S., R. 1 E., Fremont County,

Wyo. Cody shale, about 3,000 feet above base.

J. D. Love, J. B. Reeside, Jr., R. M. Thompson, and M. L.

Troyer, 1949. Six miles northeast of Lander, in the NE J£N WH

sec. 8, T. 2 S., R. 2 E., Fremont County, Wyo. Cody shale,

2,040 feet above base. .

N. H. Brown, T. W. Stanton, and E. G. Woodruff, 1909. Southeast of Lander, in T. 33 N., R. 99 W., Fremont County, Wyo.

Frontier formation.

N. H. Brown, T. W. Stanton, and E. G. Woodruff, 1909. Southeast of Lander, in T. 33 N., R. 99 W., Fremont County, Wyo.

Frontier formation, 200 feet below collection 6011.

I. A. Keyte, 1928. Two miles southeast of Lander, Fremont

County, Wyo. Frontier formation, top sandstone unit.

1. A. Keyte, 1928. Taylor ditch, near Lander. Fremont County,

Wyo. Frontier formation.

R. M. Thompson, 1944. Dallas dome, in sec. 9, T. 32 N.,' R. 98

W., Fremont County, Wyo. Frontier formation.
GEOGRAPHIC DISTRIBUTION

Localities at which scaphite cephalopods were collected from rocks of the Colorado group Continued

17

No. 

on 

fig. 

4

211

212

213

214

215

210

217

218

210

220

221

222

223

224

225

226

227

228

220

230

23.1

232

233

234

235

230

237

238

230

240

241

U.S.G.S.

Mcso/.oic 

locality 

number

18940

18941

8984

8985

21538

21757

20013

9008

. 21102

8524

8511

4448

20917

4872

9029

.10404

J0450

4000

40G9

3712

22125

530

533

399

0270

12583

22120

0045

11050

13319

934

Collector, year of collection, description of 

locality, and stratigraphic assignment

H. H. R. Sharkey, 1944. Dallas dome, in sec. 10, T. 32 N., R. 98

W., Fromont County, Wyo. Frontier formation.

H. A. Tourtelot, 1944. Derby dome, in sec. 20, T. 32 N., R. 98

W., Fromont County, Wyo. Frontier formation.

C. .T. Hares, 1914. About 30 miles east of Lander, FremontCounty, Wyo. Frontier formation.

C. J. Hares, 1914. About 30 miles east of Lauder, Fremont

County, Wyo. Frontier formation, 50 feet lower than Loc. 8984.

0. N. Pipiringos and K. Yon.no, 1949. Conant Creek, 35 miles

oast of Landor, in the NWJiSWJi sec. 13, T. 33 N., R. 94 W.,

Fremont County, Wyo. Frontier formation, 53 feet below top.

O. N. Pipiringos, 1948. Same locality as 21538. Frontier formation, near top.

J. D. Love, 1944. Conant Creek, Fremont County, Wyo. Frontier

formation.

J. B. Reosidc, Jr., 1914. Muskrat Creek, T. 32 N., R. 91 W.,

Fromont County, Wyo. Cody shale.

R. M. Thompson, 1948. Ten miles southwest of Raderville, in

tho NW}£ sec. 12, T. 33 N., R. 90 W., Fremont County, Wyo.

Cody shale, 50 to 100 feet above top sandstone of Frontier.

C. .T. Hares, 1913; Sec. 9, T. 32 N., R. 80 W., Natrona County,

Wyo. Cody shale.

C. J. Hares, 1013. Twenty-seven miles northwest of Casper, in

SCO. 30, T. 37 N., R. 82 W., Natrona County, Wyo. Frontier

formation.

C. T. Lupton, 1907. About 4.5 miles southeast of Big Muddy

station, in T. 33 N., R. 76 W., Converse County, Wyo.

J. D. Love, 1946. Eleven miles south of Douplas, in the NWJ^

NW>i sec. 5, T. 30 N., R. 71. W., Converse County, Wyo.

Frontier formation.

.15. B. Hopkins, 1907. Six miles oast of Crooks Gap oil field, in

tho NWK sec. 19, T. 28 N., R. 91 W., Fremont County, Wyo.

C. J. Hares and J. B. Roeside, Jr., 1014. One milo east of Jack

Orclvo's Ranch near Whiskey Puak, in sec. 26, T. 28 N., R. 90

W., Fromont County, Wyo. Cody shale.

N. W. Base, 1020. Lost Soldier oil field, Swcctwater County,

Wyo. Frontier formation, shale beneath top sandstone.

A. 15. Fath and C. Y. Hsich, '1920. Thirty-two miles northnorthwest of Rawlins, in sec. 7, T. 26 N., R. 88 W., Carbon

County, Wyo. Stocle shale, 1,728 feet above base.

A. C. Voatch, 1006. Three miles southeast of Rawlins, in the

NI5J4 sec. 27, T. 21 N., R. 87 W., Carbon County, Wyo. Frontier formation, 570 feet above Dakota sandstone. .

A. C. Voatch, 1900. Three miles southeast of Rawlins, in the

NWJisoc. 20, T. 21 N., R. 87 W., Carbon County/Wyo. Frontier formation.

A. C. Voatch, 1900. Fifteen miles south-southwest of Hanna, in

tho SEMNE& sec. 30, T. 20 N., R. 82 W., Carbon County, Wyo.

Frontier formation, 080 feet above Dakota sandstone.

F. V. Haydon, 1870. Medicine Bow River, southeastern Wyo.

(Frontier formation.)

A. Hyatt, and Russell, 1888. Railroad cut half a mile east of

Aurora, Carbon County, Wyo.

A. Hyatt, and Russell, 1888. Railroad cut 1 mile north of Aurora,

Carbon County, Wyo.

L. F. Ward. One milo north of Rock Creek, in sec. 30, T. 22 N.,

R. 75 W., Albany County, Wyo. Carlilo shale.

Robert Forrester, 1909. Four miles east of Oak Springs, Sevier

County, Utah, Mancos shale.

15. M. Spicker, 1924. Near Emery, Emery County, Utah. Mancos shale, Forron sandstone member.

Philip TCatich, 1049. Six miles east of Clawson, in sec. 20, T. 19 S.,

R. 8 E., Emory County, Utah. Blue Gate shale, near base.

Robert Forrostor, 1910. Irrigated Lands Company tunnel between Price and Spring Glen, Carbon County, Utah. Mancos 

shale.

J. B. Reoside, Jr., and E. M. Spieker, 1923. 300 feet north of Carbon County High School, Price, Utah. Mancos shale.

H. F. Moses, 1925. Three miles north of Woodside, in the SEJi

SWK sec. 28, T. 17 S., R. 14 E., Emery County, Utah. Mancos

shale.

T. W. Stanton, 1892. Four miles northwest of Woodside, Emery

County, Utah. Mancos shaJo.

No. 

on 

fig. 

4

242

243

244

245

240

247

248

249

250

251

252

253

254

255

250

257

258

259

200

261

262

263

264

265

266

267

268

U.S.G.S. 

Mesozoic 

locality 

. number

13240

13243

13261

13262

13263

13331

21426

21427

4303

21764

11070

11678

11685

11699

11705

13699

6252

6950

2007

7389

17431

4012

10506

7360

14305

......

21838

Collector, year of collection, description of 

locality, and stratigraphic assignment

J. B. Reeside, Jr., and E. M. Spieker, 1925. One mile west of

Desert, Emery County, Utah. Mancos shale, 20 feet above

Ferron sandstone member.

J. B. Reeside, Jr., and E. M. Spieker, 1925. One mile east of

Desert, Emery County,- Utah. Mancos shale, 970 feet above

base.

J. B. Reeside, Jr., 1925. Near Desert, Emery County, Utah.

Mancos shale, 1,250 feet above base.

J. B. Reeside, Jr., 1025. Near Desert, Emery County, Utah.

Mancos shale, 1,340 feet above base.

J. B. Reeside, Jr., 1025. Near Desert, Emery County, Utah.

Mancos shale, 1,400 feet above base.

J. D.' Fisher, 1025. Sec. 3, T. 20 S., R. 16 E., Emery County,

Utah. Mancos shale.

W. A. Cobban, 1944. Brush Creek, 9.5 miles northeast of Vernal,

in center of sec. 11, T. 3 S., R 22 E., Uintah County, Utah.

Mancos shale, 180 feet above top of Frontier sandstone member.

W. A. Cobban, 1045. Northeast side of Ashley Creek, 2.5 miles

west of Jensen, in the SWJiSEMsec. 24, T. 5 S., R. 22 E., Uintah

County, Utah. Mancos shale, about 800 feet above base.

H. S. Gale, 1907. Eleven miles north of Rangely, in sec. 12, T.

3 N., R. 102 W., Moffat County, Colo. Mancos shale.

W. A. Cobban, 1945. Three miles west of Skull Creek, in the

SEMSEJi sec. 4, -T. 3N., R. 101 W., Moffat County, Colo.

Mancos shale, top of Frontier sandstone member.

W. H. Bradley, J. B. Reeside, Jr., and J. D. Sears, 1923. Vermilion Creek, in the SW&NWK sec. 11, T. 10 N., R. 101 W.,

Moffat County, Colo. Mancos shale, 20 feet above top of Frontier sandstone member.

W. H. Bradley, J. B. Reeside, Jr., and J. D. Sears, 1923. Vermilion Creek, in the NEJ<NW}i sec. 11, T. 10 N., R. 101 W.,

Moffat County, Colo. Mancos shale, 1,002 feet above base.

W. H. Bradley, J. B. Reeside, Jr., and J. D. Sears, 1923. Vermilion Creek, in the-SEMSW}i sec. 2, T. 10 N., R. 101 W.,

Moffat County, Colo. Mancos shale, 1,222 feet above base.

W. H. Bradley, J. B. Reeside, Jr., and J. D. Sears, 1923. Vermillion Creek, in the NWJ^NEM sec. 11, T. 10 N., R. 101 W.,

Moffat County, Colo! Mancos shale, 1,642 feet above base.

W. H. Bradley, J. B. Reeside, Jr., and J. D. Sears, 1923. Same

locality as 11699. Mancos shale, 1,767 feet above base.

J. B. Reeside, Jr., 1926. Fourteen miles northwest of Craig, in

the SWJiSEJiSEJi sec. 27, T. 9 N., Ri 29 W., Moffat County.

Colo. Mancos shale.

A. S. Beekly, 1900. Edgerton Creek Gap, 10 miles south of Glenwood Springs, in sec. 1, T. 8 S., R. 80 W., Garfleld County, Colo.

Mancos shale.

C. W. Washburne, 1910. At Cedar, San Miguel County, Colo

Mancos shale.

C. W. Purington, 1806. Near Rico, Colorado. Mancos shale

within 100 feet of Dakota sandstone.

M. A. Pishel and H. F. Wright, 1911. Twelve miles southwest of

Cortez, in sec. 3, T. 34 N., R. 17 W., Montezuma' County; Colo.

J. D. Northrop, 1934. Center of NWK sec. 21, T. 30 N., R. 14 W.,

Montezuma County, Colo. Mancos shale, 475 feet above base.

C. D. Smith, 1906. North side of Mancos-Thompson Park road,

one mile southeast of Menefee ranch house, Durango coal field,

Colo. Mancos shale, in limestone ledges.

J. B. Reeside, Jr.. 1920. A mile and a half west of Durango, in the

NW^SEJi sec. 18, T. 35 N., R. 9 W., La Plata County, Colo.

Mancos shale, about 300 feet above Dakota sandstone.

C. W. Cooke, 1911. At base of mountain a quarter of a mile north

of head of Deadman's Creek, 10 miles southwest of Castle Rock,

Douglas County, Colo. Benton shale.

A. E. Brainerd and I. A. Keyte, 1928. Sixteen miles oast of 

Trinidad, in sec. 1, T. 32 S., R. 02 W., Las Animas County, Colo.

Apishapa shale, near top.

A. L. Morrow. Three miles south-southeast of Tipton, in the

SEli sec. 4, T. 9 S., R. 10 W., Mitchell County, Kans. Carlile

shale, in upper part of Blue Hill shale member.

W. A. Cobban, 1948. Three miles south-southeast of Tipton, in

the SEJi sec. 4, T. 9 S., R. 10 W., Mitchell County, Kans.

Carlile shale, in upper part of Blue Hill shale member.
18 SGAPHITOID CEPHALOPODS OF THE COLORADO GROUP

Localities at which scaphite cephalopods were collected from rocks of the Colorado group Continued

No. 

on 

fig. 

4

269

270

271

272

070 Z(O

274

275

276

277

278

279

280

U.S.O.S. 

Mesozoic 

locality 

number

H591

18874

12008

12006

10368

11593

11594

15580

13283

 16818

515

17628

Collector, year of collection, description of 

locality, and stratigraphic assignment

W. B. Emery, 1923. Top of the "Black Hill" on ShiprockBiltabito road about 14 miles west of Shiprock Agency, Navajo

Indian Reservation, San Juan County, N. Mex. Mancos shale,

150 feet below base of Tocito sandstone lentil.

N. W. Bass, 1943. On Biltabito road 15 miles west of Shiproek

bridge, San Juan County, N . Mex. Mancos shale, in sandstone

ledges.

J. B. Reeside, Jr., 1923. Center of the NWJ4SWM sec. 25, T. 30

N., R. 17 W., San Juan County, N. Mex. Mancos shale, 698

feet below base of Mesaverde formation.

J. B. Reeside, Jr., 1923. In the SW^NEM sec. 20, T. 30 N., R. 16

W., San Juan County, N. Mex. Mancos shale, 115 feet below

top.

W. E. Brysant, C. E. Dobbin, and J. B. Reeside, Jr., 1920. Fourteen miles southwest from Shiprock Mtn. (Wilson Peak), in

sec. 5or 8, T. 9 N., R. 4 W., San Juan County, N. Mex. Mancos

shale.

W. B. Emery, 1923. Two miles west of Tsenosti Trading Post,

Navajo Indian Reservation, San Juan County, N. Mex. Mancos

shale, from thin sandstone about 150 feet below base of Tocito

sandstone lentil.

W. B. Emery, 1923. Two miles west of Tsenosti Trading Post,

Navajo Indian Reservation, San Juan County, N. Mex. Mancos shale, in banded calcareous concretions 120 feet below Tocito

sandstone lentil.

C. B. Hunt, 1930. Sixteen miles northwest of San Mateo, in the 

NEJi sec. 2, T. 14 N., R. 10 W., McKinley County, N. Mex.

Mancos shale, 200 feet below base of Gallup sandstone member 

of Mesaverde formation.

B. C. Renick,1925. Senorita Canyon, Sandoval County, N. Mex.

Mancos shale.

C. B. Hunt, 1933. Three miles west of Gallina, in the SWMNWJ^

sec. 13, T. 23 N., R. 1 W., Rio Arriba County, N. Mex. Mancos

shale. '

J. W. Powell, 1887. Near Lagoon, 5 miles from Gallina, Rio

Arriba County, N. Mex. Mancos shale.

R. P. Bryson, 1937. About 7.5 miles north-northeast of north end

of El Vado Reservoir, Rio Arriba County, N. Mex.

No. 

on 

fig4

281

282

283

284

285

286

287

288

289

290

291

292

293

294

U.S.G.S. 

Mesozoic 

locality 

number

17633

17635

17637

16784

17638

15590

15600

15601

' 16115

7180

7165

3532

5596

Collector, year of collection, description of 

locality, and stratigraphic assignment

R. P. Bryson, 1937. About 7.5 miles north-northeast of El Vado

Reservoir, Rio Arriba County, N. Mex. Mancos shale.

R. P. Bryson, 1937. Near El Vado, Rio Arriba County, N. Mex.

Mancos shale.

R. P. Bryson, 1937. Upper Lagunas Creek, Rio Arriba County,

N. Mex. Mancos shale.

C. H. Dane, 1933. East of Monero and north of Denver Rio

Grande Western R. R., in northeast part of T. 31 N., R. 1 E.,

Rio Arriba County, N. Mex. Mancos shale, 1,000. feet below

base of upper part of the Hosta sandstone member of the Mesaverde formation.

C. H.Dane,1937. Near Chama-Monero road, Rio Arriba County,

N. Mex. Mancos shale.

W. S. Pike, Jr., 1931. West side of Cebolleta Mesa, in sec. 17, T. 8

N., R. 9 W., Valencia County, N. Mex. Mancos shale, 275

feet below top.

C. B. Hunt, 1930. Six miles east of Seboyeta, Valencia County,

N. Mex. Mancos shale, 679 feet above base, and 250 feet below

base of Gallup sandstone member of Mesaverde formation.

C. B. Hunt, 1930. About 5.5 miles north of Evan's Park, Cebolleta

Grant, Sandoval County, N. Mex. Mancos shale, 200 feet

below Gallup sandstone member of the Mesaverde formation.

C. B. Hunt, 1930. About 2.5 miles north-northeast of Evan's 

Ranch, Nuestra Senora de -la Luz de las Lagunitas Grant,

Sandoval County, N. Mex. Mancos shale, 400 feet below

Gallup sandstone member of the Mesaverde formation. 

C. B. Hunt, 1931. Nineteen miles southeast of Dominguez, in 

the SWJ^NWJi sec 5> T. 14 N., R. 1 E., Sandoval County,

N. Mex. Mancos shale, top of Carlile shale member.

W. T. Lee, 1911. Omera mine, east flank of Ortiz Mountains,

Santa Fe County, N. Mex. Mancos shale, uppermost part.

W. T. Lee, 1911. One mile southwest of Waldo, Santa Fe County,

N. Mex. Mancos shale, upper 200 feet, and Mesaverde formation, basal part.

W. T. Lee, 1905. One mile north of Galisteo Creek and 1 mile

east of head of Canyon del Yeso, Santa Fe County, N. Mex.

Mancos shale, uppermost part.

W. T. Lee, 1908. Outlet of Johnson Park, Raton coal field, northeastern Colfax County. N. Mex. Niobrara formation.

SYSTEMATIC DESCRIPTIONS

Scaphites delicatulus Warren var. greenhornensis Cobban, n. var. 

Plate 1, figures 1-3

This variety is represented in the collections by only 

two individuals, the smaller of which has been selected 

as the type. It is 28 mm. long, 23 mm. high, and 14.2 

mm. wide, and has about 85 ventral ribs on the exposed 

whorls of which 40 are on the living chamber. Primary 

ribs number 15 on the living chamber and about 16 or 

17 on the last septate whorl. Neither the internal 

whorls nor the suture were seen.

The variety differs from the holotype of Scaphites 

delicatulus Warren (1930, p. 66, pi. 3, fig. 3; pi. 4, 

figs. 7, 8) in its coarse ribbing near the aperture and 

greater number of primaries in proportion to the number 

of secondaries on the living chamber, the straight part 

having two or three secondaries to each primary 

whereas Warren's specimen shows four to six secondaries 

to each primary. The tubercles are not as conspicuous 

or pointed as on Warren's type. The variety more

closely resembles a specimen of S. delicatulus more 

recently figured by Warren (1947, p. 123, pi. 29, fig. 5), 

differing from it chiefly in the presence of coarse ribbing 

near the aperture and lack of pointed tubercles.

Scaphites brittonensis Moreman (1942, p. 215, pi. 34, 

figs. 1, 2; text fig. 2) from the Britton formation of 

Texas is related to the variety greenhornensis but 

differs by its smaller size, pointed tubercles, and uniform 

spacing of the ventral ribs over the entire living 

chamber. Of the European species S. d. greenhornensis 

closely resembles S. aequalis Sowerby although that 

species may lack terminal coarse ribbing. One of the 

specimens figured as S. geinitzi d'Orbigny by Geinitz 

(1874, p. 191, pi. 35, fig. 3) is coarsely ribbed at the end 

of the living chamber and appears to differ from the 

Greenhorn form only in its high, rounded tubercles.

Holotype, U.S.N.M. 106766.

The holotype is from a calcareous concretion about 

10 feet below the top of the Greenhorn formation on 

the north flank of the Black Hills uplift,, in the WK 

sec. 14, T. 9 S., R. 60 E., Carter County, Mont. The
SYSTEMATIC DESCRIPTIONS 19

external mold of part of a large specimen was found in 

the living chamber of a Vascoceras thomi Reeside in 

the Greenhorn calcareous member of the Cody shale 

on the Crow Indian Reservation in south-central 

Montana.

Scaphites larvaeformis Meek and Hayden 

Plate 1, figures 4-15

1859. Scaphites larvaeformis Meek and Hayden, Acad. Nat. Sci.

Philadelphia Proc., vol. 10, p. 58. 

.1.876. Scaphites larvaeformis Meek and Hayden. Meek, U. S.

Gcol. Survey Terr. Rept., vol. 9, p. 418, pi. 6, figs. 6a-c. 

1893. Scaphites larvaeformis Meek and Hayden. Stanton, U. S.

Geol. Survey Bull. 106, p. 182, pi. 44, fig. 2. 

1898. Scaphites larvaeformis Meek and Hayden. Logan, Kansas

Univ. Geol. Survey, vol. 4, p. 473, pi. 104, fig. 2.

1915. Scaphites larvaeformis Meek [and Hayden]. Frech, 

Centralbl. Mineralogie, Jahrg. 1915, no. 21, p. 556, 

fig. 1.

1916. Holcoscaphites larvaeformis (Meek and Hayden). Nowak, 

K.-k. Geol. Reichsanstalt Verh., Jahrg. 1916, no. 3, 

p. 66.

1927. Scaphites larvaeformis Meek and Hayden. Reeside, U. S. 

Geol. Survey Prof. Paper 150-B, p. 31.

The description by Meek (1876, p. 418)-is as follows:

Shell small, tiansversely. subovate, compressed, evenly 

rounded on the periphery;, volutions slender, nearly round, the 

inner or coiled ones forming only a very small part of the entire 

shell, and so closely involuted as to leave only a very small 

umbilical pit; extended body portion rather long, slender, and 

straight to the recurvature, thence continued backward until it 

comes nearly in contact with coiled inner volutions; aperture 

apparently circular; surface ornamented by small costae, which 

pass from the inner side of the volutions to about half way across 

their lateral surfaces, where they swell into small, obscure, 

transversely elongated nodes, and then branch each into two or 

three smaller linear ribs, all of which pass straight over the 

periphery.

Length, 0.87 inch; height, 0.63 inch; convexity, 0.33 inch.

The septa of this species are comparatively rather simple, 

being each provided with but two principal lateral lobes on each 

side, none of which are deeply divided. The siphonal lobe is 

longer than wide, and has two very small, short, nearly parallel, 

obscurely bifid, terminal divisions, with a more oblique, somewhat similar branch on each of the sides above. The first 

lateral sinus is wider than the siphonal lobe, and nearly as long, 

with its extremity deeply divided by a slender, obscurely trifid, 

auxiliary lobe, into two very unequal, more or less sinuous, and 

obtusely digitate branches- First lateral lobe about half as wide 

as the siphonal, but somewhat shorter, and bearing two very 

small terminal divisions, similar to those of the siphonal lobe. 

Second lateral sinus not larger than the outer division of the first, 

and merely obscurely divided into two very short, simple, 

obtusely rounded, terminal subdivisions. Second lateral lobe 

very small, and obscurely trifid at the end. Whether this last 

is what is usually called a ventral lobe, or whether there is 

another still smaller one beyond it, the specimen is scarcely in a 

condition to show.

To this the writer adds the following observations of 

the type specimen: Ribs on youngest part of living

chamber coarser and more widely spaced toward the 

aperture; ventral ribs on youngest part of last septate 

whorl faintly curved back forming a broad sinus on the 

venter; total number of ventral ribs on exposed whorls 

about 65, of which 29 are on the living chamber; total 

number of primary ribs 24, of which 10 are on the 

living chamber; length, 22.2 mm.; height, 16.1 mm.; 

width, 8.4 mm.

The writer has at hand 11 adult specimens of Scaphites 

larvaeformis and fragments of several times that number, all from a bed of limestone concretions in the basal 

part of the Carlile shale of the Black Hills. The adults 

range uniformly in length from 13 to 26.5 mm., averaging 21.2 mm. The living chambers have 6 to 9 primary 

ribs, averaging 7.5, and 19 to 40 secondaries, averaging 

26.9. Most are coarsely ribbed near the aperture and 

nearly all display backward bending of the ribs crossing 

the venter on the younger part of the last septate whorl. 

The young stages have .a smooth subevolute shell for 

the first three or three and a half whorls. The whorl 

succeeding the protoconch is wide and depressed. In 

the next whorl the cross section is much more rounded. 

Beginning with the third whorl, the ventrolateral 

margin becomes subangular and is raised into a faint 

ridge which is broadly undulating, forming poorly 

defined blunt nodes. On the fourth whorl, at a 

diameter of between 4.5 and 5 mm., broad weak ribs 

appear, trending straight across the venter. They are 

not of uniform strength or spacing for the next one-half 

whorl, but following that they become very high and 

uniform. Each pair of ribs unites in a ventrolateral 

node from which extends a single primary rib. At a 

diameter of about 6 mm. a few intercalated secondaries 

appear on the venter. As the whorls enlarge the 

intercalated ribs increase in abundance, the primaries 

become stronger, but the ventrolateral nodes are 

reduced to radially elongate swellings. Four or five 

whorls comprise the septate part of an adult. Many 

specimens have a very small swelling on the umbilical 

shoulder at the base of the straight part of the shell.

Scaphites larvaeformis is characterized by its small 

size, quadrangular shape with markedly straight living 

chamber, row of small, pointed ventrolateral tubercles, 

and apicad bending of the ventral ribs on the younger 

part of the last septate whorl. In addition, many 

specimens show a small umbilical swelling and, near 

the aperture, coarser ribbing than on the older part of 

the living chamber.

' A specimen figured as S. geinitzi D'Orbigny by 

Geinitz (1874, p. 191, pi.. 12, fig. 23) resembles S. 

larvaeformis in its form and in the arrangement of ribs 

and nodes, including the wide spacing of the ribs near 

the aperture, but apparently differs by possessing a 

large umbilical swelling. Schliiter (1872, p. 75, pi.
20 SCAPHITOID CEPHALOPODS OF THE COLORADO GROUP

23, figs. 12-22; pi. 27, fig. 5) figured a number of examples of S. geinitzi, all differing from S. larvaeformis 

by their larger size, more numerous nodes and primary 

ribs, and the tendency toward bigger umbilical swellings. A specimen figured by Schliiter (pi. 23, figs. 23- 

25) as Scaphites sp. closely resembles S. larvaeformis in 

its sculpture and wide spacing of the ribs near the aperture, but differs in its more rounded outline and larger 

size. Yabe's S. yonekurai (1910, p. 165, pi. 15, figs. 

4-7) shows a backward bending of the ribs over the 

venter as in S. larvaeformis, but the living chamber is 

much more depressed and does not have the row of 

nodes. . S. meriani Pictet and Campiche (1861, p. 16, 

pi. 44) closely resembles S. larvaeformis in shape and 

general sculptural features including the apicad inclined ribs on the last septate whorl, but differs in tne 

more depressed whorls and denser costation. The 

specimen figured by Collignon (1928, p. 54, pi. 5, figs. 

15, 15a, 15b) as Scaphites cf. S. meriani and later referred tentatively to S. hugardianus D'Orbigny by 

Spath (1937, p. 503) also shows rursiradiate ribbing on 

 the septate whorl.

Holotype, U.S.N.M. 229; plesiotypes, U.S.N.M. 

106743-106745. . :

The species occurs in limestone concretions in the 

lowest part of the Carlile shale of the Black Hills, associated with Collignoniceras woollgari (Mantell) and 

Inoceramus fragilis Hall and Meek.

Scaphites larvaeformis Meek and Hayden var. obesus Cobban, 

n. var.

Plate 1,. figures 16-22

This variety differs from the typical form in its decidedly stouter shell, greater size, and tendency toward 

'denser costation. Because of the stoutness, the space 

between the curved part of the living chamber and the 

septate coil is proportionally smaller than in the typical form. The holotype is 31.5 mm. long, 25.9 mm. 

high, and 16.2 mm. wide. It has 16 primary arid 60 

ventral ribs on the exposed whorls, with 8 primaries 

and 29 secondaries on the living chamber. Thirteen 

adults from the Black Hills range in length from 21 

to 37 mm., averaging 29.8 mm. These have on their 

living chambers 6 to 10 primary ribs, averaging 8, and 

24 to 45 secondaries, averaging 32.2. . . Holotype, U.S.N.M. 106767; paratype, U.S.N.M. 

106768.

The holotype is from a limestone concretion in the 

lowest part of the Carlile shale, 5 miles southeast of 

Hot Springs, Fall Biver County, S. Dak. 

Scaphites patulus Cobban, n. sp. 

Plate 1, figures 23-32

This species is closely related to Scaphites larvaeformis 

from which it differs by its more rounded outline, fewer

ribs, equal spacing of the ventral ribs on the living 

chamber, stronger tubercles, and much more depressed 

cross section of the living chamber. The general 

sculptural features, including rursiradiate ribbing on 

the last septate whorl, are similar to those of S. larvaeformis. The holotype is 31.5 mm. long, 27.5 mm. high, 

and 19.5 mm. wide. It has 18 primary ribs and 55 

secondaries on the exposed whorls, with 6 or 7 primaries 

and 27 secondaries on the living chamber. The 10 

other adults at hand-range in length from 23 to 43 

mm. and show 5 to 8 primaries and 21 to 27 secondaries 

on the living chambers.

The suture is similar to that of S. larvaeformis.

Holotype, U.S.N.M. 106769; paratypes, U.S.N.M. 

106770,106771.

The species occurs with S. larvaeformis, Collignoniceras woollgari (Mantell), and Inoceramus fragilis 

Hall and Meek, in the lowest part of the Carlile shale 

of the Black Hills. The holotype is from a limestoneconcretion found two miles southeast of Fairburn, 

Custer County, S. Dak.

Scaphites praecoquus Cobban, n. sp. 

Plate 1, figures 33-36

The holotype of this tiny species is only 10.4 mm. 

long, 8.2 mm. high, and 4.8 mm. wide. It is quadrangular in side view, and. moderately stout. The 

septate coil is not ribbed, but the. subangular ventrolateral margin is undulated into large, blunt nodes. The 

umbilicus is wider than in most scaphites from the 

Carlile shale. The living chamber, which comprises 

most of the -specimen, is uniform in size and has a very 

small umbilical swelling at its base. The straight part is 

smooth except for a few faint irregularly spaced ventral 

ribs. A row of small ventrolateral tubercles 'appears 

on the curved part, and the ventral ribs become progressively larger toward the. aperture, with those on 

the last half of the. whorl relatively coarse. Primary 

ribs are absent. The aperture is broadly ovate and 

slightly constricted.

The suture was not seen.

This species could be considered a variant of Scaphites 

larvaeformis that developed an 'uncoiled living chamber 

before other adult features were fully developed. The 

septate coil is comparable to the third 'inner whorl of 

S. larvaeformis, and the sculpture of the curved part 

of the living chamber suggests the larger species. 

However, in the younger Carlile beds, similar tiny adult 

scaphites occur that are related to contemporary larger 

species, but are distinctly different from the smallest 

adult forms of those species. By Niobrara time descendants of the small species are unlike associated 

species. It seems best to consider S. praecoquus as a
21

split from S. larvaejormis and the initial member of a 

new line of scaphite development. 

Holotype, U.S.N.M. 106758:

The holotype is from a limestone concretion near the 

base of'the Carlile shale, in the NEK sec. 15, T. 57 N., 

K. 62 W., Crook County, Wyo.

Scaphites arcadiensis Moreman 

Plate 2, figures 1-8

194.2. Scaphites arcadiensis Moreman, Jour. Paleontology, vol. 

16, no. 2, p. 216, pi. 34, fig. 3.

This species is characterized by its small size, simple 

suture, relatively few but coarse ribs, and living chamber with depressed cross section, with widely spaced 

ventral ribs on the older part, and with about five primaries raised into strong elongate nodes. The type 

specimen has 17 primary ribs on the exposed whorls and 

only 5 on the living chamber, and 48 ventral ribs on the 

exposed whorls and 18 on the living chamber. It is 26 

mm. long and 21 mm. high.

Scaphites arcadiensis is distinguished from S. palulus 

by its fewer ribs, wide spacing of the ventral ribs toward the base of the living chamber, lack of pointed 

tubercles, and lack of rursiradiate ribbing on the septate 

coil.

Plesiotypes, U.S.N.M. 106765a-c.

The holotype is from the Arcadia Park formation, 1 

mile south of Arcadia Park, Texas. In the Western 

Interior the species has been collected from the ferruginous concretions in the lower part of the Carlile shale 

of the northern Black Hills associated with Scaphites 

carlilensis Morrow and Collignoniceras hyatti (Stanton).

Scaphites carlilensis Morrow 

Plate 2, figures 9-23

1935. Scaphites carlilensis Morrow, Jour. Paleontology, vol. 9, 

no. 6, p. 466, pi. 50, figs. 4a-d.

.Shell of average size for the genus, oval in outline, 

stout, and ornamented by equispaced, straight primary 

and secondary ribs. Morrow gives the following dimensions and rib counts on the holotype: Length, 

55 mm.; width, 27 mm.; total number of ventral ribs on 

exposed whorls, 58; ventral ribs on living chamber, 27

In the northern Black Hills this species occurs 

abundantly in ferruginous concretions in the lower part 

of the Carlile shale above the zone of Scaphites larvaejormis. A collection consisting largely of the living 

chambers of 43 adults from one locality shows a range 

in. height from 27 to 55 mm., averaging 39 mm. The 

living chambers have 8 to 16 primary ribs, averaging 

10.3, and 24 to 38 secondaries, averaging 27.7. These 

specimens show normal variation for a scaphite species 

with the larger individuals stouter and more densely 

. costate than the smaller.

The suture is simple and has a broad, shallow first 

lateral saddle and fairly short bifid lobes.

Plesiotypes, U.S.N.M. 106740, 106741, 106742a-c.

The holotype is from the Blue Hill shale member of 

the Carlile shale three miles southeast of Tipton, in the 

SE% sec. 4, T. 9 S., R. 10 W., Mitchell County, Kansas, 

associated with Collignoniceras hyatti (Stanton). The 

species is known also from a widespread ferruginous 

concretion unit in the lower part of the Carlile shale on 

the north flank of the Black Hills, on the Cat Creek 

anticline of central Montana, and on the Sweetgrass 

arch of north-central Montana.

Scaphites morrowi Jeletzky

1935.. Scaphites pygmaeus Morrow, Jour. Paleontology, vol. 9,. 

no. 6, p. 465, pi. 50, figs. 2a-e, 3.

1942. Scaphites pygmaeus Morrow. Moreman, Jour. Paleontology, vol. 16, no. 2, p. 216, pi. 34, figs. 5, 6.

1949. Scaphites morrowi Jeletzky, Jour. Paleontology, vol. 23, 

no. 3, p. 330.

It is possible that this form is a small, slender variant 

of Scaphites carlilensis Morrow. Regarding a comparison of his species, Morrow (1935, p. 466) states:

Scaphites pygmaeus and S. carlilensis are very much alike in 

many details, the principal difference being in the size. The 

former is consistently smaller, all specimens being very nearly 

the size of the figured specimens. Another constant difference 

is in the number of ribs crossing the venter. S. carlilensis 

having from six to ten more.

A large collection of iSf. carlilensis from the Black Hills 

shows a fairly uniform gradation in size from specimens 

as small as Morrow's S. pygmaeus to those even larger 

than his holotype of S. carlilensis. The smaller 

specimens have fewer ribs. However, the Black Hills 

specimens have uniformly spaced ventral ribs whereas 

Morrow's S. pygmaeus has the ribs more widely 

spaced on the straight part of the living chamber than 

on the curved part. The importance and constancy 

of this feature has not been determined.

Scaphites warreni Meek and Hayden 

Plate 3, figures 8-2.1

1860. Scaphites warreni Meek and Hayden, Acad. Nat. Sci.

Philadelphia Proc., vol. 12, p. 177. 

1876. Scaphites warreni Meek and Hayden. Meek, TJ. S. Geol.

Survey Terr. Kept., vol..9, p. 420, pi. 6, fig. 5.

1876. Scaphites warreni Meek and Hayden var. wyomingensis 

Meek, U. S. Geol. Survey Terr. Rept., vol. 9, p. 421, 

text figs. 61-63.

1877. Scaphites warreni Meek and Hayden. White, U. S. Geog.

and Geol. Surveys W. 100th Mer. Rept., vol. 4, pt.'l,

p. 200 [not pi. 19, fig. 3a]. 

1893. Scaphites warreni Meek and Hayden. Stanton, U. S.

Geol. Survey Bull. 106, p. 185, pi. 40, fig. 4 [not figures

5-7]. 

1898. Scaphites warreni Meek and Hayden. Logan, Kansas

Univ. Geol. Survey, vol. 4, p. 475, pi. 104, fig. 4 [not

figs. 5-7].
22 SCAPHITOID CEPHALOPODS OF THE COLORADO GROUP

1899. Scaphites warreni Meek and Hayden. Logan, Field Mus.

Nat. History Pub., Geol. ser., vol. 1, no. 6, p. 210

[not pi. 22, fig. 1; pi. 23, fig. 5]. 

1916. Holcoscaphites warreni (Meek and Hayden). Nowak,

K.-k. Geol. Reichsanstalt Verb., Jahrg. 191G, no. 3, 

'p. 66. 

1927. Scaphites warreni Meek and Hayden. Reeside, U. S. Geol.

Survey Prof. Paper 150-B, p. 36.

Meek's description (1876, p. 420) is as follows:

Shell small, transversely subovate, moderately compressed; 

inner volutions nearly circular, closely involute, and composing 

a comparatively rather large part of the entire bulk; deflected 

body-portion short and (perhaps accidentally) rather more 

compressed proportionally than the inner tuins; surface costate, 

and without proper nodes; costae small on the inner volutions, 

where they do not differ materially in size, but on the body part 

about every fourth or fifth one becomes more prominent than 

the others, and extends entirely across.from the inner side to and 

over the periphery, in passing upon which they bifurcate, or 

give off lateral branches, so that the whole, with some intercalated 

ones, assume there a uniform size; aperture and septa unknown.

Length, 1.45 inches; height, about 1.22 inches; convexity, 

about 0.57 inch.

The foregoing description is made out from the original type 

specimen of S. warreni, which is unfortunate^ not in an entirely 

satisfactory condition, either as to form or ornamentation, while 

it shows no traces of the septa.

* * * I should remark that the specimen from which our 

figure 5, on plate 6 was drawn, seems to have had its body-pait 

accidentally compressed laterally,while its mouth or lip probably 

does not end where it would seem to in the figure, but may pass 

under the rock, and curve farther back toward the involuted 

part. It is also a little doubtful whether the latter has been 

worked out correctly, the enveloping rock adhering so fiimly to 

the shell, that in cutting it away, the inner part of the whorl is 

made to appear smooth instead of costate, and it is not quite 

clear that this part is so broad as represented. The same difficulty of having to cut away the enveloping rock has prevented 

the bifurcations of the costae, particularly the larger ones, from 

being clearly seen.

The holotype is from the southern edge of the Black 

Hills. Associated with it, and preserved in the same 

hard calcareous siltstone, is the greater part of the 

living chamber of a small, slender scaphite with ventral 

ribs more widely spaced on the straight part than on the 

curved part. The holotype is not sufficiently complete 

to demonstrate the presence of a similar type of ribspacing. Scaphites identical with the small specimen 

occur widespread in the Western Interior at one horizon 

in the Carlile shale. These grade into specimens as 

large .or larger than the holotype. The larger individuals 

are stouter and more densely ribbed than the smaller, 

a condition normal for a scaphite species. The small, 

slender form is herein set aside as S. warreni var. 

ubiquitosus. The abundant material from the Black 

Hills now at hand permits a more detailed description 

of the species and its variations.

The form typical of the species is stout, about medium 

size, subovate in outline, with small umbilicus and

living chamber considerably freed from the septate 

coil. The living chamber increases in size toward the 

bend, then tapers toward the aperture. Venter on 

last septate whorl well rounded and, on living chamber, 

broadly rounded. Living chamber slightly depressed 

in cross section; venter rounded in side view; umbilical 

wall nearly straight on older half. Aperture reniform 

and only very faintly constricted; dorsal lappet broad 

and slightly extended. Ten adults from one locality 

in the Black Hills range in length from 29 to 47 mm., 

averaging 35.2 mm.

.The early whorls are broad and depressed. Up to a 

diameter of 4 or 5 mm. they have a subangular ventrolateral margin which, in some individuals, is raised 

into a faint ridge as in Scaphites larvaeformis. Later 

whorls are higher and more rounded.

The early whorls are smooth. At a diameter of about 

3 mm. faint ribs appear that pass straight across the 

venter. . These increase in height as the whorls enlarge, 

and at a diameter of about 5 mm., primary ribs appear. 

The latter are inclined slightly forward on crossing the 

flank and, at the ventrolateral margin, they swell 

slightly and then divide into two ribs that trend 

straight across the venter. Intercalated secondary ribs 

are rare at first but become more numerous as the whorls 

enlarge, and on the last septate whorl there are as many 

as 6 secondaries for each primary rib. The sculpture 

of the living chamber consists of strong primary ribs 

and numerous weaker secondary ribs, and all are more 

closely spaced on the curved part. The primary ribs 

range from straight to somewhat sigmoid, and extend 

from the umbilical shoulder half way to the middle of 

the venter where they split into two or three secondaries. 

Near the ventral extremity of the primaries, two or 

three intercalated secondaries appear and pass straight 

across the venter. In some, specimens, particularly 

those that have a greater than average depression of the 

living chamber, the ventral extremity of the primary 

ribs is raised into an incipient elongate node. Rib 

counts on the living chambers of 13 adults from one 

locality in the Black Hills show 6 to 13 primaries, 

averaging 8.4, and 27 to 41 secondaries, averaging 34.2.

The suture is' simplified to a pseudoceratitic stage 

with broad, slightly incised 'saddles, and short lobes.

Meek (1876, p. 241, text figs. 61-63) gave the name, 

S. warreni var. wyomingensis, to a specimeD from the 

Medicine Bow River area of southeastern Wyoming. 

This specimen has been lost, but Meek's figures suggest 

an individual of average form and sculpture for the 

species.

Scaphites warreni resembles S. arcadiensis and S. 

morrowi in the wider spacing of the ventral ribs on the 

straight part of the living chamber than on the curved 

part, but it is easily distinguished by its weaker and
SYSTEMATIC DESCRIPTIONS 23

more numerous ribs and the more simplified suture. 

Frech's $. warreni var. silesiaca (1915, p. 557, figs. 3a, 

3b) is much more densely costate, shows uniform rib 

spacing, and has an umbilical swelling; it should be 

regarded as a distinct species.

Holotype, U.S.N.M. 225; plesiotypes, U.S.N.M-. 

106746-106750.

This species occurs in the lower third of the Turner 

sandy member of the Caiiile shale of the Black Hills 

associated with Inoceramus dimidius White and Prionocyclus macorribi Meek. It is especially abundant in the 

Mancos shale of the San Juan Basin of northwestern 

New Mexico and southwestern Colorado.

Scaphites warreni Meek and Hayden var. ubiquitosus Cobban,

n. var.

Plate 3, figures 26, 27; plate 4, figures 1-15

1877. Scaphites warreni Meek and Hayden. "White, U. S. Geog. 

and Geol. Surveys W. 100th Mer. vol. 4, pt. 1, pi. 19, 

fig. 3a.

The small size and slender shell characterize this 

variety. The holotype is 24 mm. long, 18.7 mm. high, 

and 10.5 mm. wide. There are 21 primary ribs and 

64 secondaries on the exposed whorls, with 7 primaries 

and 33 secondaries on the living chamber. The collection from the Mancos shale of New Mexico from which 

the holotype was selected consists of 12 adults ranging 

in length from 20 to 31 mm., averaging 25.8 mm., and 

having on their living chambers 5 to 9 primary ribs,, 

'averaging 7.4,.and 27 to 44 secondaries, averaging 35. 

A collection of 26 individuals from one locality in the 

Black Hills shows a similar range in size and number 

of primaries, but the ventral ribs on the living chamber 

average only 32.2.

Holotype, U.S.N.M. 106751; paratypes, U.S.N.M. 

106752-106754.

The types are from a thin sandstone in the Mancos 

shale about 150 feet below the base of the Tocito 

sandstone lentil.

Scaphites warreni Meek and Hayden var. haydeni Cobban, n. var. 

Plate 3, figures 22-25

Relatively few but exceptionally strong primary ribs 

characterize this-variety. The holotype is of about 

average size and stoutness for the typical form of the 

species. It is 38.8 mm. long, 33 mm. high, and 21.7 

mm. wide. It shows 13 primary ribs and 64 secondaries on the exposed whorls, with 4 primaries and 30 

secondaries on the living chamber.

The suture is simplified to a pseudoceratitic stage.

Holotype, U.S.N:M. 106761.

The type was collected by F. V. Hayden from the 

Medicine Bow River area in the Laramie Basin, southeastern Wyoming. This is a rare form that is known

elsewhere only from central Wyoming, the Black Hills, 

and the San Juan Basin of northwestern New Mexico.

Scaphites veterinovus Cobban, n. sp. 

Plate 3, figures 1-7

Adults of this tiny species are only 10 to 15 mm. in 

length. The holotype is 11.5 mm. long, 10 mm. high, 

and 6 mm. wide. The coiled part has a fairly wide 

umbilicus, rounded umbilical shoulder, narrow and 

slightly flattened flanks, subangular ventrolateral margin raised into a ridge, and well rounded venter. The 

older half of the living chamber is markedly straight, 

and shows broadly rounded flanks grading evenly into 

the rounded venter. The aperture has a small dorsal 

lappet and incipient lateral lappets.

Whorls less than 5 mm. in diameter are smooth. 

From that diameter to the base of the living chamber, 

the sculpture consists of straight ventral ribs.. The 

living chamber is crossed by 30 to 45 evenly spaced 

ventral ribs that die out on the flanks. The holotype 

has about 7 faint primary ribs on the living chamber, 

but many specimens show none.

The suture is very simple.

In size and ornamentation this species resembles 

Scaphites minutus Moreman (1942, p. 216, pi. 34, figs. 

9, 10) from the Britton formation of Texas, but that 

species has a wider, umbilicus and is more densely 

ribbed.

Holotype, U.S.N.M. 106763; paratype, U.S.N.M. 

106764.

This species is known only from the S. warreni zone 

in the lower part of the Turner sandy member of the 

Carlile shale of the Black Hills. The types are from 

calcareous concretions 14.5 feet above the chert pebbleshark tooth conglomerate in the Turner, five miles north 

of Belle Fourche, in the SW^SE^SW^ sec. 11, T. 9 

N., R. 2 E., Butte County, South Dakota.

Scaphites ferronensis Cobban, n. sp. 

Plate 4, figures 16-29

This species is closely related to Scaphites warreni 

Meek and Hayden. In size and suture these species 

are almost identical, and the rib arrangement is similar 

in that the curved part of the living chamber has more 

closely spaced' ribs that the straight part. However, 

there are important differences. The ventral ribs on 

the living chamber of S. jerronensis are much more 

dense than those of S. warreni, but the primaries are 

fewer. On internal molds the ribbing on the curved 

part of the living chamber is weak, and on many specimens, this part of the shell is- smooth. The smaller 

and more slender individuals are commonly more nearly 

quadrangular in outline than similar-sized specimens of 

S. warreni Arar. ubiquitosus.
24 SCAPHITOID CEPHALOPODS or THE COLORADO GROUP

S.ferronensis is based largely on a collection (U.S.G.S. 

Mes. loc 12583) of 19 adults from the Ferron sandstone 

member of the Mancos shale near Emery, Utah. These 

range in length from 25 to 39.5 mm., averaging 33.1 mm., 

and in height from 19 to 35.5 mm. averaging 24.6 mm. 

The ventral ribs on the exposed whorls number 86 to 

99, and the primaries 13 to 25. The living chambers 

have 35 to 56 ventral ribs, averaging 46, and 4 to 7 

primaries, averaging 5.1. The holotype is 26 mm. long, 

24 mm. high, and 13.6 mm. wide. It has 92 ventral 

ribs and 18 primaries, with 47 secondaries and 5 primaries on the living chamber.

Holotypes, U.S.N.M. 106759; paratypes, U.S.N.M. 

106760a-b. .

The holotype is from the Ferron sandstone member 

near Emery, Utah. The species also occurs in the 

Mancos shale 275 feet below the top on the west side 

of the Cebolleta Mesa, Valencia County, central western New Mexico; in the top of the Frontier sandstone 

member of the Mancos shale of northwestern Colorado 

and northeastern Utah; and in the top of the Frontier 

formation of the Laramie Basin, southeastern Wyoming.

Scaphites whitfieldi Cobban, n. sp. 

Plate 4, figures 30-40; plate 5, figures 1-4

1880. Scaphites w.arreni Meek and Hayden. Whitfield, U. S.

Geog. and Geol. Survey Rocky Mtn. Region Rept. on

Black Hills, p. 444, pi. 13, figs. 1-4. 

1880. Scaphites wyomingensis Meek. Whitfield, U. S. Geog. and

Geol. Survey Rocky Mtn. Region Rept. on Black

Hills, p. 446, pi. 13, figs. 5-7. 

1893. Scaphites warreni Meek and Hayden. Stanton, U. S.

Geol. Survey Bull. 106, pi. 40, figs. 5-7. 

1898.. Scaphites warreni Meek and Hayden. Logan, Kansas

Univ. Geol. Survey, vol. 4, pi. 104, figs. 5-7. 

1899. Scaphites warreni Meek and Hayden. Logan, Field Mus.

Nat. History Pub., Geol. ser., vol. 1, no. 6, pi. 23, fig. 5. 

1910. Scaphites warreni Meek and Hayden. Grabau and

Shimer, North American index fossils, p. 176, fig.

1427a, b. 

1915. Scaphites warreni Meek [and Hayden]. Frech, Centralbl.

Mineralogie, Jahig. 1915, no. 21, p. 557, figs. 4a, 4b. 

1944. Scaphites warreni Meek and Hayden. Shimer and Shrock,

Index fossils of North America, p. 591, pi. 244, fig. 6.

Adult shell of average size for the genus, quadrangular in outline, and slender to moderately stout. Sculpture consists of dense, evenly spaced ribs.

The cross section of the whorl succeeding the protoconch is wide and depressed. The second whorl is 

much higher and more rounded, and the next two are 

almost circular or, in many individuals, distinctly 

compressed with slightly flattened flanks. The umbilicus is wide in the first whorl and narrow in the rest. 

Up to a diameter of 4 mm. the ventrolateral margin is 

subangular and raised into a faint ridge. Between 

whorl diameters of 4 and 6 mm. this ridge becomes

fainter, gradually disappearing. The living chamber, 

which begins after the fifth whorl succeeding the 

protoconch, is of nearly uniform size, with only a very 

small and gradual expansion toward the aperture. 

The umbilical area of the living chamber is broad and 

"gently sloping on the straight part but is steeply 

inclined on the curved part. The aperture is reniform, 

slightly constricted, and has a small dorsal lappet. 

A collection of 12 adults from the type locality on the 

north flank of the Black Hills shows lengths ranging 

from 28 to 47 mm., averaging 37.2 mm., although 

fragments of larger individuals are known (pi. 5, 

fig. 1). The holotype is 35 mm. long, 28 mm. high, 

and 13.5 mm. wide.

The inner whorls are smooth to a diameter of 4.5 mm., 

where ventral ribs appear. Primary ribs appear 

between diameters of 7 and 8 mm. On the first half of 

the last septate whorl the primaries trend straight from 

the umbilicus to a point a third of the distance to the 

middle of the venter. There they split into two ribs, 

with one or two intercalated secondaries. On the last 

half of the septate whorl and on the living chamber, the 

primaries are decidedly sigmoidal and strongly inclined 

forward. Each primary splits into 2 or 3 secondaries, 

and each group of secondaries is separated by 2 to 6 

intercalaries. The ribs are equally strong and evenly 

spaced as they cross the venter. The holotype has 24 

primary ribs and 115 secondary ribs on the exposed 

whorls, with 8 primaries and 63 secondaries on the 

living chamber. As many as 133 secondary ribs are 

visible on an adult shell. Twelve specimens from the 

type locality have living chambers with 6 to 9 primaries, 

averaging 7.6, and 37 to 75 secondaries, averaging 52.

The suture is simple and resembles that of Scaphites 

warreni, but the' elements tend to be more elongate.

Scaphites whitfieldi is easily distinguished by its 

slender, quadrangular shape and the dense, evenly 

spaced ribbing. Some specimens of S. jerronensis are 

as quadrangular and densely costate as S. whitfieldi but 

differ by their unequal spacing of ribs on the venter 

of the living chamber. The form described by Frech 

(1915, p. 557, figs. 3a, b) as S. warreni var. silesiaca 

has ribbing comparable to that of S. whitfieldi but is 

oval in shape and has an umbilical swelling.

The species is named for R. P. Whitfield.

Holotype, U.S.N.M. 106735; paratypes, U.S.N.M. 

12258a, 106736, 106737, 106738a-b.

The types are from calcareous and ferruginous concretions in the Turner sandy member, 251 to 264 feet 

above the base of the Carlile shale, six miles north of 

Belle Fourche, in the NJ$ sec. 10, T. 9 N., R. 2 E., Butte 

County, South Dakota, associated with Inoceramus perplexus Whitfield and Prionocyclus wyomingensis Meek. 

The species has been collected from many localities
SYSTEMATIC DESCRIPTIONS 25

around the Black Hills in the middle third of the Turner 

sandy member of the Carlile shale. It is known also 

from the Carlile member of the Cody shale in the Crow 

Indian Reservation in south-central Montana, from 

the top of the Frontier formation of the Laramie Basin 

of southeastern Wyoming, and from the Mancos shale 

at many localities in Colorado. Utah, and New Mexico.

Scaphites pisinnus Cobban, n. sp. 

Plate 5, figures 5-8

Adult shell tiny, oval in outline, with relatively large 

living chamber and'small septate coil. The latter has a 

fairly wide umbilicus, narrow flanks, subangular ventrolateral margin raised into a faint ridge, and well-rounded 

venter. The living chamber increases uniformly in size 

to the aperture. The venter and dorsum are almost 

evenly curved in side view. The flanks and venter are 

well rounded. The aperture is incomplete, but weakly 

developed lateral lappets are indicated. The holotype 

is 8.6 mm. long, 7 mm. high, and 4 mm. wide.

The septate coil is smooth. The sculpture of the 

living chamber consists of about 25 equispaced ventral 

ribs that are arched slightly forward. About 6 primary 

ribs are present but scarcely discernible.

The suture is one of the simplest known for any of the 

adult scaphites of the Colorado group. The ventral 

lobe is as broad as high, with a wide siphonal saddle. 

The first lateral saddle is broader than the ventral lobe 

and asymmetrically bifid. The first lateral lobe is bifid 

and half as large as the ventral lobe. The second, 

lateral saddle is bifid and as wide as the first lateral lobe. 

The second lateral lobe is very small and undivided. 

The third lateral saddle is bifid and a little larger than 

the second lateral saddle. The internal suture was not 

seen.

This species differs from Scaphites veterinovus in its 

oval outline, smooth septate coil, fewer ribs on the living 

chamber, and larger incipient lateral lappets.

Holotype, U.S.N.M. 106762.

The species occurs with S. whitfieldi in the middle 

part of the Turner sandy member of the Carlile shale of 

the northern Black Hills. The holotype is from a bed of 

ferruginous concretions 251 to 264 feet above the base 

of the Carlile shale, six miles north of Belle Fourche, in 

the NK sec. 10, T. 9 N., R. 2 E., Butte County, S. Dak.

Scaphites nigricollensis Cobban, n. sp. 

Plate 6, figures 1-17; plate 7, figures 1-5

Shell elliptical in outline, moderately stout, with small 

umbilicus, and living chamber considerably freed from 

the septate coil and commonly laterally inflated at its 

base. The internal whorls are circular to slightly wider

than high in cross section; the last whorl is usually laterally compressed. The umbilicus is wide only up to a 

diameter of 4 or 5 mm. The living chamber is almost 

uniform in size, and has slightly flattened flanks and 

well-rounded venter. The aperture is faintly constricted, about as high as wide, and has small dorsal 

lappet. Adults are slightly larger than average for the 

genus. Seventeen specimens from the type locality in 

the Black Hills range in length from 37 to 63 mm., 

averaging 51.6 mm. The holotype is 54 mm. long, 43 

mm. high, and 21 mm. wide.

The first three and a half whorls are smooth. Weak 

ventral ribs first appear at. a diameter of 5 mm. Primary ribs appear at a diameter of about 10 mm. On 

the. last septate whorl about two secondary ribs are 

present to each primary, whereas on the living chamber 

the ratio of secondaries to primaries is about four to one. 

The ribs are fairly straight and, on the venter, evenly 

spaced. On internal molds the ribbing is weak on the 

older half of the living chamber, and on many individuals 

the venters are smooth (pi. 6, figs. 9, 11). The secondaries extend well down between the primaries. The 

holotype has 30 primaries and 111 secondaries on the 

exposed whorls, with 14 primaries and 52 secondaries on 

the living chamber. Rib counts on the living chambers 

of 18 adults from the type locality show 9 to 15 primaries, averaging 11.4, and 38 to 58 secondaries, averaging 49.

The suture, although fairly simple, is slightly more 

complex than that of Scaphites whitfieldi.

The diagnostic features of S. nigricollensis are the 

swelling at the base of the living chamber, numerous 

primary and secondary ribs, and the tendency toward 

loss of ribbing on the older half of the living chamber 

of internal casts. This loss of ribbing is similar to that of 

S. jerronensis, but S. nigricollensis differs in its larger 

size, uniform spacing of ventral ribs, and the greater 

number of primary ribs. Of European species S. nigricollensis is nearest to the form described by Frech (1915, 

p. 557, figs. 3a, 3b) as S. warreni var. silesiaca from the 

upper Turonian.

Holotype, U.S.N.M. 106730; paratypes, U.S.N.M. 

106731a-d, 106732.

The types are from calcareous concretions 59 feet 

below the top of the Turner sandy member (and 294 

feet above the base of the Carlile shale), six miles north 

of Belle Fourche, in the NEtfNEtfNWtf sec. 10, T. 

9 N., R. 2 E., Butte County, S. Dak. Outside the 

Black Hills region, the species occurs in the Carlile 

member of the Cody shale in the Crow Indian Reservation of south-central Montana, and in the Colorado shale 

about 650 to 750 feet below the top in north-central 

Montana.
26 SCAPHITOID CEPHALOPODS OF THE COLORADO .GROUP

Scaphites nigricollensis Cobban var. meeki Cobban, n. var. 

Plate 5, figures 9-26

This variety is smaller and more slender than the 

typical form and the living chamber is proportionally 

more extended. The ribs, which are fewer and stronger, 

are retained on all internal molds of living chambers. 

The flanks of the living chamber are more rounded, 

and no specimen has a lateral swelling at the base. 

The abundant specimens show intergradation with the 

typical form.

The holotype is 31 mm. long, 24.5 mm. high, and 

12.3 mm. wide. It has 25 primary ribs and 71 secondaries on the exposed whorls, with 10 primaries and 36 

secondaries on the living chamber. Thirty-two adults 

from the type locality range in length from 26 to 50 

mm., averaging 34.4 mm., and have on their living 

chambers 7 to 14 primary ribs, averaging 10, and.29 

to 50 secondaries, averaging 40.

The suture has narrower lobes than those of the 

typical form.

This variety resembles Scaphites whitfieldi in size, 

suture, and general sculpture, but differs in its oval 

shape, coarser ribbing, and living chamber with 

fewer ventral ribs and more primary ribs.

Holotype, U.S.N.M.- 106733; paratypes, U.S.N.M. 

106734a-d.

The types are from calcareous concretions 59 feet 

below the top of the Turner sandy member (and 294 

feet above the 'base of the Carlile shale), six miles 

north of Belle Fo.urche, in the NEtfNE^NWK sec. 10, 

T. 9 N., R. 2 E., Butte County, S. Dak.

Scaphites corvensis Cobban, n. sp. 

Plate 7, figures 6-10

This species is characterized by its moderately large 

size, stout form, slightly inflated .living chamber, and 

suture with narrow lobes. It was derived from Scaphites 

nigricollensis and differs from that species in its slightly 

larger size, more rounded flanks, retention of the ventral 

ribbing on "internal molds of living chambers, and in 

its more deeply incised suture with narrower elements. 

In contrast to the lateral swelling at the base of the 

living chamber of S. nigricollensis, the entire living 

chamber of S. corvensis is swollen.

The holotype is 63.5 mm. long, 53.5 mm. high, and 

27 mm. wide. It has 28 primary ribs and 92 evenly 

spaced ventral ribs on the exposed whorls, with 15 

primaries and 52 secondaries on the living chamber.

Holotype, U.S.N.M. 106755.

The holotype is from a calcareous concretion 180 

feet above the base of the Carlile shale member of the 

Cody shale, 33 miles south of Hardin, on the Crow 

Indian Reservation, in the E#NW#SW# sec. 36, T. 6 

S., R. 32 E., Big Horn County, Mont. The species

is known also from the Sage Breaks member and the 

uppermost part of the Turner sandy member of tho 

Carlile shale of the Black Hills.

Scaphites corvensis Cobban var. bighornensis Cobban, n. var. 

Plate 7, figures 11-17

This variety differs from the typical form in its 

smaller size, more slender whorls, more depressed cross 

section of living chamber,, and stronger sculpture with 

fewer ribs. The internal whorls have not been seen, 

but the outer whorls are well rounded in cross section 

and have a relatively wide and deep umbilicus. The 

living chamber is long, almost uniform in size, and 

considerably extended beyond the septate coil. The 

flanks and venter are rounded and intergrade evenly. 

The aperture is almost as high as wide, with small 

dorsal lappet. The holotype is 44.5 mm. long, 36.5 

mm. high, and 20 mm. wide.

The sculpture on the coiled part of the holotype 

consists of 14 primary ribs that pass straight out from 

the umbilicus and commonly cross the venter without 

forking. Well out on the flank these ribs are separated 

by one or two secondaries. The sculpture on the living 

chamber of the holotype consists of 10 primary ribs 

and 33 ventral ribs. The primaries are arched forward. 

A third of the way out from the umbilicus to the middle 

of the venter they become higher and branch into two 

or three high sharp ribs that cross the venter with a 

slight forward swing.

This variety is distinguished from Scaphites nigricollensis var. meeki by its stronger sculpture with fewer 

ribs and its more incised suture with narrower lobes.

Holotype, U.S.N.M. 106756.

The holotype is from a calcareous concretion 180 

feet above the base of the Carlile shale member of the 

Cody shale, 33 miles south of Hardin, in the EJjjNWji 

SWK sec. 36, T. 6 S., R. 32 E., Big Horn County, 

Mont. The variety is known. also from the Sage 

Breaks member and the uppermost part of the Turner 

sandy member of the Carlile shale of the Black Hills.

Scaphites preventricosus Cobban, n. sp. 

Plate 9, figures 1-16

Adult shell, large, stout, oval in outline, and ornamented by fairly straight primary and secondary ribs 

that are uniformly spaced on the living chamber. 

Although most of the living chamber is freed from the 

septate coil, it is curved so that very little space exists 

between the aperture and the septate coil.

The first whorl succeeding the protoconch is wide 

and depressed in cross section. The second whorl is 

much higher proportionally than the first, and the 

third whorl is almost circular. Later whorls are 

broader than high with depressed cross sections.
SYSTEMATIC DESCRIPTIONS 27

About six whorls make up the coiled part. The 

umbilicus is wide in the early whorls and narrow in 

the later. The living chamber is stout, with rounded 

venter and broadly rounded to slightly flattened flanks. 

The venter of the living chamber is curved in side view, 

whereas the umbilical shoulder of the older part is 

straight. The living chamber is almost uniform in 

size from its base to a point a short distance beyond 

the place where the umbilical shoulder begins to curve, 

and there it becomes depressed in cross section and 

gradually tapers to the aperture. . The aperture is 

slightly constricted, a-little wider than high, and with 

small dorsal lappet.. The adult shell is larger than 

average for the genus. The holotype is 75 mm. long, 

68 mm. high, and 39.5 mm. wide. Eleven adults from 

Montana and Wyoming sufficiently complete for measurement range in length from 68 to 77 mm., averaging 

74 mm.

The coiled part is smooth up to a diameter of 3 mm. 

where f aint ventral ribs appear. These quickly increase 

in strength and become coarse about a quarter of a 

whorl beyond the point of first appearance. At a 

diameter of 8 mm. there are about 25 of these ribs per 

whorl. Primary ribs appear at this diameter. They 

are inclined backward on crossing the umbilical wall, 

but on reaching the umbilical shoulder, bend forward 

and cross the flank with a forward inclination. The 

ventral ribs have a lesser forward inclination. All ribs 

are less curved on the younger whorls, and on the last 

septate whorl, they pass almost straight out from the 

umbilicus. The early whorls have about two secondary 

ribs to each primary rib, .wheras the last septate whorl 

has 3 or 4 secondaries to each primary. The sculpture 

on the living chambers of ten adults consists of 36 to 

49 secondaries and- 6 to 15 primaries. These ribs are 

straight or slightly flexuous, and are evenly spaced on 

the venter. The holotype has 90 secondaries and 23 

primaries on the exposed whorls, with 45 secondaries 

and 10 primaries on the living chamber.

The suture is complex and has bifid lobes. The first 

lateral lobe is commonly asymmetric with the dorsal 

branches larger than the ventral.

This species is easily distinguished from older scaphites by its larger size and more complex suture. Of 

the younger scaphites, Scaphites preventricosus is most 

closely related to S. ventricosus Meek and Hayden 

(Meek and Hayden 1862, p. 22), from which it can be 

distinguished by its smaller size, more extended living 

chamber, denser costation, and uniformly spaced ventral 

ribs.

Holotype, U.S.N.M.. 106675--paratypes, U.S.N.M.. 

106676 a-d, 106679.

 The holotype is from a bed of calcareous concretions 

in the Colorado shale, 514 to 525 feet below the top, in

the north bank of the Marias River, 5.5 miles south of 

Shelby, in the NE# sec. 20, T. 31 N., R. 2 W., Toole 

County, Mont. The"species is known also from many 

other localities in central, north-central, and northwestern Montana,, in the Colorado shale 400 to 580 

feet below the top. In central and western Wyoming 

it occurs in the-upper part of the Frontier formation.

Scaphites preventricosus Cobban var. sweetgrassensis Cobban

n. var.

Plate 10, figures 18-25

This variety differs from the typical form of the 

species in its smaller size, more slender form, and more 

extended living chamber. The holotype is 60 mm. 

long, 52 mm. high, and 28.5 mm. wide. It has 109 

secondaries and 28 primaries on the exposed whorls, 

with 50 secondaries and 11 primaries on the living 

chamber. Nine adults from the type locality range in 

length from 51 to 67 mm., averaging 59.7 mm., and 

have 34 to 58 secondaries on the living chambers.

This variety can be readily distinguished from all 

earlier scaphites by its larger size and more complex 

suture., It can be differentiated from the slender 

variants of later species by the more extended living 

chamber.

Holotype, U.S.N.M. 106677; paratype, U.S.N.M. 

106678.

It occurs with the typical form of the species in 

Montana and Wyoming. The holotype is from a bed 

of calcareous concretions 514 to 525 feet below the top 

of the Colorado shale, in the north bank of the Marias 

River, 5.5 miles south of Shelby, in the NEK sec. 20, 

T. 31 N., R. 2 W., Toole County, Mont.

Scaphites preventricosus Cobban var. artilobus Cobban, n: var. 

Plate 8, figures 1-6

This variety is based on a small collection from one 

locality in north-central Montana. It differs from the 

typical form of .the species by its compressed form, 

flexuous ribbing, and suture with narrow lobes. The 

living chamber is fairly short, almost uniform in size, 

and considerably extended beyond the septate coil. 

The venter is rounded and the flanks are flattened on 

both the living chamber and the septate coil. The 

type specimen is 60 mm. long, 50 mm. high, and 24 mm. 

wide.

The sculpture consists of numerous thin, flexuous 

primary and secondary ribs, with more than 100 

visible on the adult. The holotype has 23 primaries 

and 63 secondaries on the septate coil, and 16 primaries 

and 49 secondaries on the living chamber.

The suture is characterized by narrow lobes. The 

siphonal lobe is as high as wide, with long, slender 

branches and narrow saddles. The first lateral saddle
28 SCAPHITOID CEPHALOPODS OF THE COLORADO GROUP

is very broad and divided asymmetrically by a long, 

narrow bifid lobe, and the saddles are dissected by long, 

narrow lobes. The first lateral lobe is bifid and a little 

smaller than the siphonal lobe. The second lateral 

saddle is bifid and as large as the first lateral lobe. The 

second lateral lobe is small, bifid, and with very narrow 

stem and branches. Remaining elements are small 

and show narrow lobes.

This variety differs from Scaphites preventricosus var. 

sweetgrassensis by its compressed form and suture with 

narrower lobes. It is known only from the base of the 

S. preventricosus zone whereas the var. sweetgrassensis 

ranges throughout the zone. The narrow-lobed suture 

is much like that of S. corvensis and S. c: bighornensis, 

but is more incised.

Holotype, U.S.N.M. 106680.

Known only from the-Colorado shale 617 to 634 feet 

below the top, on the north bank of the Marias River, 

5.5 miles south of Shelby, in the NE% sec! 20, T. 31 N., 

R. 2 W., Toole County, Mont.

Scaphites mariasensis Cobban, n. sp. 

Plate 8, figures 14-17

Shell large and stout with living chamber but slightly 

extended beyond the septate coil. Umbilicus of average size. Umbilical wall of older half of living chamber 

straight for half its length and then directed outward 

almost at right angles. The holotype is 75.0 mm. 

long, 67.5 mm. high, and 41.0 mm. wide.

The sculpture consists of numerous high, sharp ribs, 

the holotype showing 28 primaries and 81 ventral ribs 

on the exposed whorls, with 15 primaries and 49 ventral 

ribs on the living chamber. The ventral ribs on.the 

living chamber are equispaced and extend well down 

on the flanks between the primaries.

The suture is relatively simple in comparison with 

that of the associated species, Scaphites preventricosus. 

The short, wide first lateral lobe has a broad supporting stem.

This species closely resembles S. preventricocsus in 

size, shape, and stoutness. The sculpture of S. mariasensis, however, is much stronger and the primaries 

are more numerous.

Holotype, U.S.N.M. 106681.

The species is known only from the Colorado shale, 

620 to 636 feet below the top, on the north bank of the 

Marias River, 5.5 miles south of Shelby, in the NE% 

sec. 20, T. 31 N., R. 2 W., Toole County, Mont.

Scaphites mariasensis Cobban var. gracillistriatus Cobban,

n. var.

Plate 8, figures 7-13

The holotype is an internal mold that does not preserve the inner whorls. The shell is oval in outline,

slender, and of average size. It is 46 mm. long, 36 

mm. high, and 19 mm. wide. The septate part is 

crushed and incomplete. The living chamber is large 

in proportion to the rest of the shell and considerably 

extended beyond the septate coil. It is nearly uniform 

in size and has slightly flattened flanks and rounded 

venter. The aperture is about as high as wide and 

has a very small dorsal lappet.

The septate coil is densely costate with thin, flexuous 

ribs. The sculpture on the living chamber consists of 

54 ventral ribs and 17 primary ribs, all narrow and 

sharp. The primaries are markedly flexuous, and 

turn sharply forward on crossing the flanks. The 

secondaries begin well down on the flanks.

The suture is simple, with lobes and saddles progressively decreasing in size away from the venter.

Holotype, U.S.N.M. 106682; paratype, U.S.N.M.' 

106683. '

The holotype is from the Colorado shale 620 to 636 

feet below the top, on the north bank of the Marias 

River, 5.5 miles south of Shelby, in the NE% sec. 20, 

T. 31 N., R. 2 W., Toole County, Mont.

Scaphites impendicostatus Cobban, n. sp. 

Plate 11, figures 1-14

This species is characterized by its stout form, conspicuous umbilical swelling, aperture with outwardturned ventral margin, and peculiar ribs that are 

either flat-crested or curved back.

The first whorl succeeding the protoconch is broad 

and depressed in cross section. The subsequent whorls 

are proportionately higher, but all are broader than 

high. The umbilicus is wide in the early whorls and 

narrow in the later. The venter of the living chamber 

is broadly rounded and grades evenly into the flattened 

flanks. There is a prominent umbilical swelling at the 

base of the living chamber. The aperture is wider 

than high, slightly constricted, and has a normal 

dorsal lappet.' The ventral margin of the aperture, 

however, shows an unusual feature. It is extended 

slightly and bent away from the rest of the shell, and, 

in the holotype, there is some thickening of the shell 

here (pi. 11, fig. 8). The adult shell is stout, quadrangular in outline, and of about average size for the genus. 

The holotype is 50 mm. long, 42 mm. high, and 27 mm. 

wide. Other specimens range in length from 37 to 

55 mm.

Ventral ribs first appear at a diameter between 3 and 

4 mm., and primary ribs appear at a diameter of about 

6 mm. These ribs are curved and spaced like the early 

ribs of Scaphites preventricosus. The ribs on the last 

septate whorl and on the straight part of the living 

chamber assume a form unique among the scaphites of 

Colorado age. As shown on plate 11, figure 7, each
SYSTEMATIC DESCRIPTIONS 29

rib is strongly flattened on the distal end and produced 

into a flange on the aboral side. In contrast the ribs 

on the curved part of the living chamber are sharp and 

curved backwards. On the holotype the primaries on 

the coiled part are flat as they leave the umbilicus, and 

at a point a quarter of the way to the middle of the 

venter, they are twisted so that one of the edges becomes nearly or quite vertical. The ribs abruptly flatten again and remain so on crossing the venter where they 

are separated by one or two flat secondaries. On the 

living chamber the primaries bifurcate about a quarter 

of the distance from the umbilicus'to the middle of the 

venter. The ribs of the adult shell are slightly flexuous. They are of equal strength and spacing on the 

venter. There are 93 secondary ribs and 29 primary 

ribs visible on the holotype. The living chamber has 

59 secondaries and 17 primaries.

The suture is simple. The siphonal lobe is longer 

than wide, with a high saddle. The first lateral saddle 

is asymmetrically bifid and broader than the siphonal 

lobe. The first lateral lobe is bifid and as wide as the 

siphonal lobe, but only half as long. The second lateral 

saddle is bifid and about half as large as the first lateral 

saddle. The second lateral lobe is small and trifid. 

The third lateral saddle is bifid and slightly smaller than 

the second lateral saddle. The third lateral lobe is very 

small and bifid or trifid. The internal suture was not 

seen.

This species is easily distinguished from other scaphites by its form and sculpture. In size, umbilical 

swelling, and density of ribs it somewhat resembles the 

European Turonian forms figured by Leonard (1897, 

p. 61, pi. 6, figs. 7,8a-b) as Scaphites lamberti Grossouvre 

and later referred by Frech (1915, p. 557) to his S. 

warreni var. silesiaca. Scaphites impendicostatus differs, however, in its flat ribs, stout form, and marked 

quadrangular shape. Several scaphite species have 

umbilical swellings and outward bending of the ventral 

margin of the aperture, and thus resemble S. impendicostatus, but all are much smaller and lack the flattened 

ribs. Typical examples of these scaphites are S. condoni 

Anderson (1902, p. Ill, pi. 2, figs. -58-63) from the 

Cretaceous of Oregon, and the following species from 

. the Coniacian of Japan: $.? pseudoaequalis Yabe (1910, 

p. 163, pi. 15, figs. 1-3), £.? yonekurai Yabe (1910, 

p. 165, pi. 15, figs. 4-7), Yezoites planus Yabe (1910, 

p. 167, pi. 15, figs. 12-15), arid Yezoites ainuanus Shimizu 

(Yabe, pi. 15, fig. 16).

Holotype, U.S.N.M. 106686; paratypes, U.S.N.M. 

106687-106689.

The holotype is from a calcareous concretion in the 

Colorado shale 195 feet above the top of a calcareous 

shale of Greenhorn age, 1.5 miles north of Fort Shaw, 

 in the SE# sec. 35, T. 21 N., R. 2 W., Cascade County,

Mont. The species! is moderately abundant in the 

Colorado shale 500 to 550 feet below the top, on the 

Sweetgrass arch of north-central Montana, associated 

with Scaphites preventricosus. It occurs also in the 

upper part of the Frontier formation of the Wind River 

and Laramie basins of Wyoming, and in the Mancos 

shale of central Utah.

Scaphites impendicostatus Cobban var. erucoides Cobban, n. var. 

Plate 11, figures 15-28

This variety departs considerably from the typical 

form of the species. It is smaller, more slender, lacks 

an umbilical swelling and upturned ventral apertural 

margin, and has fewer ribs.

The adult shell is small, ranging in length from 20 to 

42 mm. The holotype is 35.5 mm. long, 30 mm. high, 

and 18.5 mm. wide. The shell is stout, quadrangular 

in side view, and with umbilicus of normal size. The 

living chamber is long, stout, uniform in size, and with 

the older half straight.

The sculpture consists of numerous high sharp primary and secondary ribs. On the living chamber the 

ribs are exceptionally high and the crest of each rib 

tends to be curved slightly back. Some large individuals have flattened ribs. The holotype has 86 

ventral ribs and 33 primary ribs on the exposed whorls, 

of which 41 secondaries and 16 primaries are on the 

living chamber.

The suture is that of the species.

Holotype, U.S.N.M. 106690; paratypes, U.S.N.M. 

106691, 106692 a-b.

The holotype is from the top of the Frontier formation at Sage Creek, in sec. 18, T. 1 S., R. 1 E., Fremont 

County, Wyo.

Scaphites uintensis Cobban, n. sp. 

Plate 10, figures 5, 6

The collection from which the type was selected consists of crushed specimens in shale. The holotype is 

an impression in the shale, and an artificial cast of it is 

figured.

The shell is small subovate in outline, and with 

narrow umbilicus.' The older half of the living chamber is straight. The holotype is 26 mm. long and 20 

mm. high.

The sculpture of the coiled part consists of numerous fairly straight primary ribs each forking at the 

mid^flank into two secondaries. On the living chamber the primaries consists of about 10 or 11 straight ribs 

which begin as prominent elongate swellings on the 

umbilical shoulder and terminate in a row of tubercles 

on the ventrolateral margin. Numerous fine ribs cross 

the venter of the straight part, whereas coarse distantly 

spaced ribs occur on the venter and flank of the curved

930551 51-
30 SCAPHITOID CEPHALOPODS OF THE COLORADO GROUP

part. The ratio of secondaries to primaries on the 

straight part is about six to one.

The suture is rather simple.

This species closely resembles Scaphites delicatulus 

var. greenhornensis in size, shape, and ornamentation, 

but can be distinguished by the incipient umbilical 

nodes and the higher ratio of secondary to primary ribs 

on the living chamber.

Holotype, U.S.N.M. 106702; paratype, U.S.N.M. 

106703.

The species is known only from the Mancos shale 172 

to 192 feet above the top of the Frontier sandstone 

member, on the south flank of the Uinta Mountains, 

9.5 miles northeast of Vernal, in the WK sec. 11, T. 3. S., 

R. 21 E., Uintah County, Utah.

' Scaphites frontierensis Cobban, n. sp. 

Plate 10, figures 1-4

This species is based on a small, somewhat distorted 

specimen. The septate coil is normal and very densely 

ribbed. The living chamber is straight for half its 

length and largely freed from the septate coil. The 

sculpture on the venter of the living chamber consists 

of fine, closely spaced ribs on the straight part and 

coarse, widely spaced ribs on the curved part. Along 

the ventrolateral margin are six round nodes, largest on 

the curved part. Several subequal nodes are evenly 

spaced along the umbilical margin of the straight part. 

Obscure ribs connect these with the ventrolateral 

tubercles, but otherwise the flanks are smooth.

The suture is not discernible.

This species is close to Scaphites uintensis but it has 

fewer tubercles, and they are strongest on the curved 

part of the living chamber, whereas, in S. uintensis, 

the ventrolateral nodes are weakest on the curved part.

Holotype, U.S.N.M. 106704.

The holotype is from a sandstone bed in the Frontier 

formation 180 feet below the top, on Bacon Creek, 

in the NEKNE}^ sec. 22, T. 41 N., R. Ill W., Teton 

County, Wyo.

Scaphites sagensis Cobban, n. sp. 

Plate 10, figures 7-10.

Shell of average size and shape for the genus with the 

living chamber largely freed from the septate coil. The 

holotype, a distorted specimen, is 33±mm. long, 

27± mm. high, and 23± mm. wide.

The sculpture of the septate coil consists of relatively 

few, coarse, straight primary and secondary ribs. The 

living chamber likewise has relatively few ribs; there 

are only 6 primaries and 30 secondaries .on the holotype. 

The ventral ribs are equispaced on both the straight 

and curved parts. Six Ventrolateral tubercles are 

present on the living chamber of the holotype. The

primary ribs are straight and rise into high, elongate 

nodes about in the middle of the flank on the older part 

of the liying chamber.

The suture has not been seen.

The ventrolateral tubercles and elongate flank nodes 

ally this species to Scaphites uintensis and S. frontierensis, but it has fewer and more uniformly spaced 

ventral ribs.

Holotype, U.S.N.M. 106696; paratype, U.S.N.M. 

106697. '

This species is known only from the upper part of the 

Frontier formation 'of the Wind River Basin, Wyo. 

The holotype is from a sandstone concretion in the 

upper part of the Frontier formation 1.3 miles north of 

Sage Creek, in the SE% sec. 30, T. 2 N., R. 1. W., Fremont County, Wyo.

Scaphites auriculatus Cobban, n. sp. 

Plate 10, figures 11-17

This tiny species is represented in the collections by 

twelve specimens ranging in length from 7.8 to 11.5 

mm. The holotype is 9.7 mm. long and 8.8 mm. high.

The first and second whorls are wide and depressed 

in cross section. The third whorl is proportionally 

higher than the earlier whorls, and the fourth whorl 

is slightly more depressed. The umbilicus is wide in 

the first two whorls and narrow in the next two. The 

living chamber, which begins after the fourth complete 

whorl, is long, curved, and almost entirely freed from 

the septate coil. In cross section the living chamber is 

wider than high with broadly rounded venter and more 

sharply rounded flanks. The aperture is much wider 

than high and has dorsal, ventral, and lateral lappets. 

The dorsal lappet is broad and extended very little but 

the ventral lappet is. narrower and more extended. The 

lateral lappets are long, narrow, and pointed, directed 

laterally and a little forward.

The coiled part is completely smooth or the last 

whorl may have weak ribs crossing the venter. This 

weak ribbing extends to the living chamber, but on 

some individuals the ribbing there is much stronger. 

The living chamber shows 6 to 9 large blunt primary 

ribs, which are the only ornamentation on some specimens. The living chamber of the holotype has 8 primaries and 31 secondaries.

The suture is simple. The siphonal lobe is a little 

longer than wide. The first lateral "saddle is broader 

than the siphonal lobe and asymmetrically bifid. The 

first lateral lobe is bifid and half as large as the siphonal 

lobe. The second lateral saddle is bifid and a little 

wider than the first lateral lobe but only half as long. 

The second lateral lobe is bifid.and very small. The 

third lateral saddle is bifid and as large as the second 

lateral lobe. The third lateral lobe is undivided and
SYSTEMATIC DESCRIPTIONS 31

half as large as the second lateral lobe. The internal 

suture was not seen.

This species is easily distinguished by its very small 

size and narrow, pointed lateral lappets. It resembles 

Scaphites pisinnus in size and shape but can be distinguished by its weaker sculpture and more extended 

lateral lappets. S. auritus Schliiter (1872, p. 77, pi. 23, 

figs. 5-9), S. puerculus var. teshioensis Yabe .(1910, 

p. 171, pi. 15, figs. 23-27), and S. perrini Anderson 

(1902, p. 114, pi. 2, figs. 71-73) bear lateral lappets 

but of an entirely different shape from those of 

S. auriculatus.

Holotype, U.S.N.M. 106684; paratype, U.S.N.M. 

106685.

The species occurs in the Colorado shale 500 to 550 

feet below the top, on the Sweetgrass arch, northcentral Montana, associated with S. preventricosus and 

S. impendicostatus. The holotype was collected from 

a calcareous concretion 521 to 527 feet below the top 

of the Colorado shale, on the north bank of the Marias 

River, 5.5 miles south of Shelby, in sec. 20, T. 31 N., 

R. 2 W., Toole County, Mont.

Scaphites ventricosus Meek and Hayden 

Plate 12, figures 1-10; plate 13, figures 11-13

1.862. Scaphites ventricosus Meek and Hayden, Acad. Nat. Sci.

Philadelphia Proc., vol. 14, p. 22. 

1876. Scaphites ventricosus Meek and Hayden. Meek, U. S.

Geol. Survey Terr. Kept., vol. 9, p. 425, pi. 6, figs. 7, 8. 

1893. Scaphites ventricosus Meek and Hayden. Stanton, U. S.

Geol. Survey Bull. 106, p. 186, pi. 44, figs. 8, 9; pi.

45, fig. 1 [not pi. 44, fig. 10].

1898. Scaphites ventricosus Meek and Hayden. Logan, Kansas 

Univ. Geol. Survey, vol. 4, p. 476, pi. 104, figs. 8, 9; 

pi. 105, fig. 1 [not pi. 104, fig. 10].

1899. Scaphiles ventricosus Meek and Hayden. Stanton, U. S.

Geol. Survey Mon. 32, p. 636.

1903. Scaphites ventricosus Meek and Hayden. Douglass, Carnegie Mus. Annals, vol 2, no. 1, p. 8. 

1927. Scaphites ventricosus Meek and Hayden. Reeside, U. S.

Geol. Survey Prof. Paper 150-A, p. 6, pi. 3, figs. 11-18;

pi. 4, figs. 1-4. 

1927. Scaphites ventricosus Meek and Hayden. Reeside, U. S.

Geol. Survey Prof. Paper 150-B, p. 35, pi. 10, figs. 1, 2. 

1944. Scahpites ventricosus Meek and Hayden. Shimer and

Shrock, Index fossils of North America, p. 591, pi. 244,

fig. 10.

The holotype is large and stout, and the umbilicus is 

of average size for the genus. The outer septate 

whorl is much wider than high, and has a broadly 

rounded venter and sharply rounded flanks. The living 

chamber is nearly circular in cross section, and in side 

view, the umbilical wall of the older half is nearly 

straight whereas the entire venter is evenly curved. 

The younger part of the living chamber is missing but 

evidently it was not in contact with the septate coil. 

The holotype is 79 mm. long and 47.6 wide.

The sculpture of the holotype consists of coarse, 

fairly straight primary and secondary ribs. The ventral 

ribs are more widely spaced on the middle of the living 

chamber than on the extremities. The complete specimen probably had 16 or 17 primaries and about 65 

secondaries on the exposed whorls and possibly 9 or 10 

primaries and 34 or 35 secondaries on the living chamber. On the middle of the living chamber 4 or 5 secondaries are present to each primary.

The suture of the holotype is not preserved and Meek 

figured the suture of a specimen that may have 'been 

associated with the type. The suture is complex and 

has symmetrically bifid lobes.

Scaphites ventricosus was derived from S. preventricosus and differs from that species in many respects. 

S. ventricosus is larger; some individuals are more than 

100 mm. in length. As the living chamber is less freed 

from the septate coil, the aperture lies at an angle different 

from that on S. preventricosus. Commonly the lateral 

margin of the aperture forms a right angle with the 

straight part of the umbilical wall of the living chamber, whereas in S. preventricosus, owing to the greater 

enrolling of the living chamber, this angle averages 

about 70 degrees. The ribbing of S. ventricosus is less 

uniformly spaced and considerably coarser than that 

of S. preventricosus.

'Holotype, U.S.N.M. 1903; plesiotypes, U.S.N.M. 

106698-106700, 106757.

The holotype is from the upper part of the Colorado 

shale about twenty miles northeast of Fort Benton, 

Mont. On the Kevin-Sunburst dome in northcentral Montana, the species occurs sparingly in the 

Colorado shale 300 to 400 feet below the top, associated with the coiled Inoceramus species /.- exogyroides 

Meek and Hayden, /. umbonatus Meek and Hayden, 

and /. undabundus Meek and Hayden. In northwestern 

Wyoming Scaphites ventricosus is present in the lower 

part of the Cody shale.

Scaphites tetonensis Cobban, n. sp. 

Plate 14, figures 1-10

This species, of about average size for the genus, is 

characterized by its strong, coarse ribbing, high primary 

ribs on the living chamber, and widely spaced ventral 

ribs on the older part of the living chamber. The holotype is 42.5 mm. long, 37 mm. high, and 25 mm. wide.

Whorls less than 6 mm. in diameter have not been 

seen. The early whorls are broad and depressed in 

cross section and ornamented by straight, fairly coarse 

ventral ribs and curved primary ribs that are inclined 

forward. About 30 ventral ribs are on a complete 

whorl 12 mm. in diameter. The last septate whorl has 

a depressed cross section due to the broadly rounded 

venter and more sharply rounded flanks. The iunbil-
32 SCAPHITOID CEPHALOPODS OF THE COLORADO GROUP

icus is fairly small and has an indistinct rounded 

shoulder. This whorl is much more densely ribbed 

than the internal whorls. The living chamber is 

straight for half its length, wider than high, and has 

rounded flanks and venter. It is crossed by 26 to 43 

straight secondary ribs and 7 to 9 flexuous primary ribs. 

The ventral ribs are widely spaced on the straight part 

and closely spaced on the curved part. The primaries 

are strong and attain their maximum height at the ventrolateral margin.

The holotype shows 71 ventral ribs and 23 primaries 

on the exposed whorls, of which 37 ventral ribs and 9 

primaries are on the living chamber. The aperture is 

wider than high and has a very short dorsal lappet. 

The ventral lappet is bent outward a little.

The suture is fairly simple. The most distinctive 

feature is the first lateral lobe, which has a saddle for 

each of the two main branches about as large and as 

high as or higher than the central saddle.

Scaphites tetonensis was derived from S. impendicostatus by becoming less unrolled and developing fewer 

ribs, which are widely spaced on the straight part of 

the living chamber. It is associated with S. ventricosus 

but is much smaller, more slender, has stronger primaries raised into incipient nodes on the living chamber, 

and a much simpler suture.

Holotype, U.S.N.M. 106707; paratype, U.S.N.M.. 

106708.

The holotype is from a sandstone bed in the Cody 

shale 538 feet above the base, in the NE^NWX sec. 20, 

T. 42 N., R. 112 W., Teton County, Wyo., where'it is 

associated with S. ventricosus and Inoceramus umbonatus 

Meek and Hayden. The species is known also from 

the lower part of the Cody shale of the west side of the 

Bighorn Basin of northwestern Wyoming, and from 

the Mancos shale of east-central Utah.

Scaphites binneyi Eeeside 

Plate 14, figures 11-16

1927. Scaphites vermiformis Meek and Hayden var. binneyi 

Reeside, U. S. Geol. Survey Prof. Paper 150-A, p. 8, 

pi. 6, figs. 1-8.

Shell about average size for the genus, moderately 

stout, with living chamber partly straightened and 

considerably freed from the septate coil. The lateral 

margin of the aperture forms an angle of 90 degrees or 

less with the straight umbilical wall of the older part 

of the living chamber. The holotype is 39 mm. long, 

35 mm. high, and 24 mm. wide.

The inner whorls are not visible in the specimens at 

hand. The last septate whorl is densely ribbed. The 

spacing of the ribs widens greatly on the older or 

straightened part of the adult living chamber and then 

gradually becomes closely spaced again on the younger

or curved part. On the living chamber the primary 

ribs end in ventrolateral tubercles that are strongest 

where the ribs are most widely spaced.

The suture is fairly simple and closely resembles that 

of Scaphites tetonensis. The first lateral lobe is characterized by high lateral saddles.

Holotype, Yale Peabody Mus. 6417; plesiotypes, 

U.S.N.M. 106705, 106706.

, This is a very rare species known only from the Cody 

shale of central and northwestern Wyoming. The 

holotype is from the Cody shale, 800 feet above the 

base, on the Oregon Basin anticline, in sec. 6, T. 51 

N., R. 100 W., Park County, Wyo.

Scaphites interjectus Reeside 

Plate 14, figures 17-21"

1927. Scaphites ventricosus Meek and Hayden var. inlerjectus 

Reeside, U. S. Geol. Survey Prof. Paper 150-A, p. 7, 

pi. 5, figs. 1-4 [not fig. 5].

This is a stout species whose living chamber is 

largely in contact with the outer septate whorl. The 

lateral edge of the aperture forms an obtuse angle with 

the umbilical wall of the living chamber. Sculpture of 

the living chamber consists of straight ventral ribs 

more widely spaced on the older part, and slightly 

curved primary ribs ending in ventrolateral tubercles. 

The suture, which is moderately incised, has large, high 

lateral saddles on the first lateral lobe, a characteristic 

feature of the scaphites of the S. tetonensis-S. binneyi 

group.

Holotype, Yale Peabody Mus. 6416; plesiotype, 

U.S.N.M. 106701.

The species is rare. The holotype is from the Cody 

shale 800 feet above the base, in Oregon Basin, sec. 6, 

T. 51 N., R. 100 W., Park County, Wyo. Reeside 

records it also from the Garland anticline, 31 miles 

northeast of Oregon Basin. One specimen (pi. 14, 

figs. 17-21) was collected from the Cody shale of the 

Lander area in the Wind River Basin, Wyo.

Scaphites depressus Reeside 

Plate 15, figures 6-8

1927. Scaphites ventricosus Meek and Hayden var. depressus 

Reeside, U. S. Geol. Survey Prof. Paper 150-A, p. 7, 

pi. 5, figs. 6-10.

This is one of the biggest scaphites of Colorado age. 

The adults range in length from 73 to 94 mm. All 

specimens are exceptionally stout and have the last 

septate whorl very deressed. In the largest individuals 

the entire adult living chamber is in contact with the 

septate coil. The umbilicus is of average size for the 

genus. The adult living chamber attains its greatest 

width in the older half, then tapers evenly to the 

aperture. The venter of the living chamber is uniformly curved; the umbilical wall is gently curved for
SYSTEMATIC DESCRIPTIONS 33

half its length and is then straightened and directed 

outward forming an obtuse angle with the older part. 

The aperture is wider than high and has a very small 

dorsal lappet. The inner whorls are stout; the last 

septate whorl is so depressed that the width of the 

shell is as great as or greater than the height.

The early whorls are somewhat coarsely ribbed, but 

the last septate, whorl is finely ribbed. From the 

beginning of the living chamber, the ribbing gradually 

becomes more widely spaced to a point about midway 

to the aperture, then gradually becomes denser toward 

the aperture. On the older part of the living chamber 

there are five or six secondaries for each primary.

The suture is complex. The first lateral lobe is 

bifid, with the dorsal branch commonly a little logger 

than the ventral branch.

This species is most closely related to Scaphites 

ventricosus and Clioscaphites montanensis var. hesperius, 

n. gen. and sp. It differs from S. ventricosus in its 

greatly depressed outer septate whorl, denser costation, 

more tightly coiled shell, and lateral margin of the 

aperture directed outward at an obtuse angle to the 

umbilical wall of the older part of the living chamber. 

It differs from Clioscaphites montanensis var. hesperius 

mainly in having a larger umbilicus and in lacking 

uniform spacing of the ventral ribs.

Holotype, Yale Peabody Mus. 6417; plesiotype, 

U.S.N.M. 106693.

The holotype is from the Cody shale, 800 feet above 

the base, in sec. 6, T. 51 N., R. 100 W., Park County, 

Wyo. It is known also from other localities in the 

Bighorn Basin of northern Wyoming and southern 

Montana, where it is associated with Inoceramus 

umbonatus Meek and Hayden, Baculites asper Morton, 

B. codyensis Reeside, and Texanites shoshonensis 

(Meek).

Scaphites depressus Reeside var. stantoni Reeside 

Plate 15, figures 1-5

1893. Scaphites ventricosus Meek and Hayden. Stanton, U. S.

Geol. Survey Bull. 106, p. 186, pi. 44, fig. 10 [not pi.

44, figs. 8, 9; pi. 45, fig. 1J. 

1898. Scaphites vonlricosus Meek and Hayden. Logan, Kansas

Univ. Geol. Survey, vol. 4, p. 476, pi. 104, fig. 10 [not

pi-. 104, figs. 8, 9; pi. 105, fig. 1]. 

1927. Scaphites ventricosus Meek and Hayden var. stantoni

Reeside, U. S. Geol. Survey Prof. Paper 150-A, p. 7,

pi. 3, figs. 19, 20; pi. 4, figs. 5-10.

This variety differs from the typical form of the 

species in its smaller size, more slender shape, and in 

having the younger part of'the living chamber slightly 

separated from the septate coil. The holotype is 59.2 

mm. long, 49 mm. high, and 34.6 mm. wide. Other 

specimens from Wyoming range from 48 to 70 mm. in 

length.

The sculpture on the adult consists of numerous 

fine and fairly straight primary and secondary ribs, 

the ribbing is dense on the last septate whorl and on the 

younger part of the living chamber. The holotype has 

97 ventral ribs and 31 primary ribs on the exposed 

whorls of which 55 ventral ribs and 16 primaries are on 

the living chamber. Other specimens from Wyoming 

have 75 to 103 ventral ribs on the adult shell with 11 to 

16 primaries and 45 to 56 secondaries on the living chamber. On the middle part of the living chamber there 

are 4 or 5 ventral ribs for each primary.

The suture is moderately complex.

Holotype, U.S.N.M. 18817; plesiotype, U.S.N.M. 

106695.

The holotype is from the upper part of the Colorado 

shale on Cinnabar Mountain near Gardiner, Park 

County, Mont. Tbe variety is common in the 

lower half of the Cody shale of the Bighorn Basin, 

Wyo., and in the Colorado shale of southern and 

southwestern Montana.

Scaphites depressus Reeside var. oregonensis Reeside

1927. Scaphites ventricosus Meek and Hayden var. oregonensis 

Reeside, U. S. Geol. Survey Prof. .Paper 150rA, p. 7, 

pi. 6, figs. 11-15.

This form is much like Scaphites depressus var. 

stantoni in size and shape but has higher, thin, sharp 

ribs and higher primaries.

Holotype, Yale Peabody Mus. 6411.

The variety occurs with the typical form of the 

species and with S. depressus var. stantoni in northern 

Wyoming and southern Montana. The holotype is 

from the Cody shale, 800 feet above the base, in sec. 6, 

T. 51 N., R. 100 W., Park County, Wyo.

Scaphites coloradensis Cobban, n. sp.

Plate 18, figures 1-6

This species closely resembles Scaphites auriculatus 

in size, shape, and in the details of the aperture, but 

the first lateral lobe of the suture is trifid rather than 

bifid. The living chamber is broader and more depressed than that of S. auriculatus, and the sculpture 

tends to be more pronounced. The holotype is 9.8 

mm. long, 8 mm. high, and 5 mm. wide. On the living 

chamber are 22 coarse ventral ribs and 6 or 7 scarcely 

discernible primary ribs. Three other specimens from 

the type locality range in length from 7.7 to 12.3 mm.

Holotype, U.S.N.M. 106715; paratype, U.S.N.M. 

106714.

This species is known only from the Colorado shale 

234 to 252 feet below the top, on the Kevin-Sunburst 

dome of north-central Montana. The holotype is 

from a calcareous concretion on the east bank of the 

Marias River, in the NEXSEM sec. 14, T. 31 N., R. 

4 W., Toole County, Mont. Associated fossils
34

include Clioscaphites vermiformis (Meek and Hayden) 

and C. montanensis, n. sp.

Scaphites leei Reeside 

Plate 21, figures 24-26 ' 

1927. Scaphites leei Reeside, U. S. Geol. Survey Prof. Paper 

151, p. 26, pi. 20, figs. 17-22; pi. 21, figs. 1-7.

This small species is characterized by its stout form, 

simple suture, and living chamber with four umbilical 

nodes, smooth flanks, and row of ventrolateral nodes. 

It is distinctly different from its associates, Clioscaphites novimexicanus (Reeside), and Desmoscaphites 

erdmanni n. sp., of the uppermost part of the Colorado 

shale, and represents the first appearance of the $. 

hippocrepis-\ike scaphites that dominate the Telegraph Creek and Eagle faunas.

Holotype, U.S.N.M. 73354; plesiotypes, U.S.N.M. 

106720 a-b.

The holotype is from the Uppermost part of the 

Mancos shale, one mile southwest of Waldo, Santa Fe 

County, New Mexico. The species is known also 

from the uppermost part of the Mancos shale of eastcentral Utah, from the Steele shale of central Wyoming, and from the Colorado shale 10 feet below the 

top, on the Sweetgrass arch of north central Montana.

Genus CLIOSCAPHITES Cobban, n. gen.

Type species. Clioscaphites montanensis Cobban.

Etymology. From the Greek kleio, close. A closed 

or tightly enrolled scaphite in contrast to the typical 

open forms with living chambers freed from the septate 

coil.

The distinguishing generic characters are the closely 

coiled shell, the dorsum of the adult living chamber 

entirely in contact with the septate coil, and the suture 

with the trifid or asymmetrically bifid first lateral lobe.

Clioscaphites montanensis Cobban, n. sp. 

Plate 16, figures 1-11; plate 17, figures 1-3; plate 20, figures 1-4

Flattened flanks, small umbilicus, rather dense 

evenly spaced ribs, and complex suture characterize 

this species. The adults are large, attaining lengths 

as great as 105 mm. Sixteen adults from the type 

locality average 69.2. mm. in length; the smallest is 

46.5 mm. long. The holotype is 61 mm. long, 52.5 

mm. high, and 32.5 mm. wide.

The shell is tightly coiled and only a few small, 

slender specimens have a little of the oral end of the 

living chamber free from the septate whorl. In side 

view the venter of the living chamber is nearly evenly 

curved; the umbilical wall is straight for half its length 

and then directed outward, forming a large obtuse 

angle. An unusual feature is the migration of the 

flank upon the umbilicus. In some specimens, such

as the holotype (pi. 16, fig. 1), the umbilicus is largely 

covered. The aperture is nearly circular and almost 

lacks a dorsal lappet.

The sculpture consists of numerous straight evenly 

spaced primary and secondary ribs, the holotype having 

32 primaries and 96 secondaries on the exposed whorls 

with 20 primaries and 66 secondaries on the living 

chambers. The living chambers of thirteen adults from 

the type locality show 13 to 20 primaries, averaging 

17.3, and 51 to 69 secondaries, averaging 61.5. On 

the living chamber 4 or 5 secondaries are present for 

each primary. The secondaries extend well down 

between the primaries. There is a tendency, particularly in the larger individuals, for the primaries to 

attain their greatest height at the margin of the venter.

The suture is deeply incised and reaches the highest 

degree of complexity of the scaphites of the Colorado 

group. The first lateral lobe is in a transitional stage 

from bifid to trifid owing to elongation of the dorsal 

terminal branch and atrophy of the ventral branches.

Large individuals approach Scaphites interjectus in 

size, general form, and in having the primaries highest 

at the margin of the venter. However, Clioscaphites 

montanensis has more flattened and extended flanks, 

more tightly enrolled shell, denser costation, and differs in sutural details. A few smaller and more slender 

specimens with fewer ribs having the living chamber 

near the aperture slightly freed from the septate coil, 

and thus resemble the varieties stantoni and oregonensis 

of Scaphites depressus. These small specimens can be 

distinguished by the more flattened flanks of the living 

chamber, smaller umbilicus, and complex suture with 

a highly asymmetrical first lateral lobe.

Holotype, U.S.N.M. 106716; paratypes, U.S.N.M. 

106717 a-d, 106726 a-d.

The types are from calcareous concretions in the 

Colorado shale, 234 to 252 feet below the top, on the 

east bank of the Marias River, 11 miles southwest of 

Shelby, in the WJSNEtfSEtf sec. 14, T. 31 N., R. 4 W., 

Toole County, Mont., where they are associated 

with Clioscaphites vermiformis (Meek and Hayden), 

Scaphites coloradensis, n. sp., and Baculites codyensis 

Reeside. Other specimens have been collected from 

the upper part of the Colorado shale at several localities in northwestern, north-central, and central Montana, and a little above the middle of the Cody shale 

of the Bighorn and Wind River Basins of Wyoming.

Clioscaphites montanensis Cobban var. hesperius Cobban, n. var. 

Plate 16, figures 12-14'; plate 17, figures 4-7

This variety differs from the typical form of the 

species in its much more inflated form, less flattened 

flanks, which are little advanced over the umbilicus,
SYSTEMATIC DESCRIPTIONS 35

and fewer and coarser ribs. The type is 74.5 mm. 

long, 61 mm. high, and 43.5 mm. wide.

Some specimens of Scaphites depressus rather closely 

resemble this variety in shape and ribbing but are 

distinguishable by the larger umbilicus, the lack of 

equal-spaced ventral ribs, and by sutural details.

.TColotype, U.S.N.M. 106718; paratype, U.S.N.M. 

106719.

This variety is known only from the upper part of 

the Colorado shale of the Sweetgrass arch of northcentral Montana. The holotype is from a bed of calcareous concretions 234 to 252 feet below the top of 

the Colorado shale, in the east bank of the Marias 

River, 11 miles southwest of Shelby, in the W^NE%SE# 

sec. 14, T. 31 N., R. 4 W., Toole County, Mont.

Clioscaphites vermiformis (Meek and Hayden) 

Plate 18, figures 7-27

1862. Scaphites vermiformis Meek and Hayden, Acad. Nat. Sci.

Philadelphia, vol. 14, p. 22. 

1876. Scaphites vermiformis Meek and Hayden. Meek, U. S.

Geol. purvey Terr. Kept., vol. 9, p. 423, pi. 6, fig. 4. 

1893. Scaphites vermiformis Meek and Hayden. Stanton, U. S.

Geol. Survey Bull. 106, p. 183, pi. 44, fig. 3. 

1898. Scaphites vermiformis Meek and Hayden. Logan, Kansas

Univ. Geol. Survey, vol. 4, p. 474, pi. 104, fig. 3. 

1910. Scaphites vermiformis Meek and Hayden. Grabau and

Shimer, North American index fossils, p. 176, fig. 1427c. 

1916. Holcoscaphites vermiformis (Meek and Hayden). Nowak,

K-k. Geol. Reichsanstalt Verh., Jahrg. 1916, no. 3, p. 66. 

1927. Scaphiles vermiformis Meek and Hayden. Reeside, U. S.

Geol. Survey Prof. Paper 150-A, p. 7, pi. 6, figs. 9, 10.

Meek fully described the adult shell which came from 

the upper part of the Colorado shale of north-central 

Montana. He apparently saw only the single specimen 

for he does not mention the internal whorls, the growth 

stages, or variations of the adult. The writer has at 

hand more than a hundred specimens from north-central 

Montana, which makes possible a more detailed 

description of the species and variations.

All whorl sections are broader than high and very 

depressed. The venter is well rounded on the early 

whorls, broadly rounded to flattened on the last 

septate whorl, and broadly rounded on the living 

chamber. The flanks are rounded on the early whorls 

and flattened on the later whorls and body chamber. 

The ventrolateral margin is rounded on the first two 

whorls out to a diameter of about 1.5 mm. It is subangular between whorl diameters of 1.5 to 6 mm. and 

then becomes rounded on the remainder of the shell. 

The umbilicus is wide in the early whorls and narrow 

in the later ones; umbilical shoulder rounded. The 

living chamber is curved and not freed from the 

septate coil; its flanks are nearly flat and inclined 

inward. The aperture is constricted, subcircular, and

has a very small dorsal lappet. The adult shell is 

subcircular in side view, slender to moderately stout, 

and a little larger than average size for the genus. The 

holotype is 53.8 mm. long,.45.1 mm. high, and 32 mm. 

wide (from extremities of nodes). Nineteen adults 

from one locality in north-central Montana range in 

length from 25 to 57 mm., averaging 50.7 mm.

The early whorls are smooth to a diameter of about 

4 mm., where coarse, rounded ventral ribs appear. 

These are sigmoid, curving back from the ventrolateral 

margin and then forward on crossing the venter. 

There are 23 to 29 ribs on the first completely ribbed 

whorl. Primary ribs first appear between diameters 

of 5 and 6 mm. and curve forward on crossing the narrow flank. The coarse ventral ribbing continues to 

the beginning of the last septate whorl where the ribs 

suddenly become sharp, dense, and straight. This 

dense ribbing continues nearly to the younger end of 

this whorl where the ribs gradually become more 

widely separated. The ribbing is sparse on the older 

half. of the living chamber, but on the younger half 

it again becomes dense. Ihe primary ribs on the living 

chamber are high, sharp, and nearly straight, and each 

terminates at the margin of the venter in a high sharp 

tubercle. 1 hese tubercles are largest in the middle 

third of the living chamber and become progressively 

smaller toward the extremities, disappearing near the 

aperture and on the youngest part of the last septate 

whorl. On the holotype the nodes are arranged on each 

side of the venter in alternate positions, but in most 

individuals the nodes are paired. The holotype has 

23 primary ribs and 74 secondary ribs on the exposed 

whorls, with 14 primaries and 45 secondaries on the 

living chamber. The living chambers of 19 specimens 

from one locality in northern Montana have 10 to 16 

primaries, averaging 13, and 33 to 53 secondaries, 

averaging 40.7. On the middle part of the living 

chamber there are 3 ventral ribs to each primary.

The suture is fairly complex and characterized by 

trifid lobes. The siphonal lobe is almost as wide as 

high. The first lateral saddle is asymmetrically bifid 

and wider than the siphonal lobe. The first lateral lobe 

is trifid and as broad but not as high as the siphonal 

lobe. The second lateral saddle is bifid and about as 

wide as the first lateral saddle but only half as long. 

The second lateral lobe is trifid and about half as large 

as the first lateral lobe. The remaining lobes are small 

and trifid. The rest of the saddles are small and bifid.

The diagnostic features of this species are the closely 

coiled shell, completely curved living chamber, row of 

ventrolateral tubercles, and fairly complex suture with 

trifid lobes. Immature specimens can be distinguished 

from juveniles of the associated species, Clioscaphites
36 SCAPHITOID CEPHALOPODS OF THE COLORADO GROUP

montanensis, by the forward bending of the ribs as they 

cross the venter. In addition, most young specimens of 

C. vermiformis are stouter.

A few individuals (pi. 18, figs. 20, 21) have sharp, 

knife-like ribs and nodes and, in this respect, exactly 

parallel the development of Scaphites depressus var. 

oregonensis Reeside.

Holotype, U.S.N.M. 1902; plesiotypes U.S.N.M. 

106713a-f.

The species is present in the Mancos shale of northwestern New Mexico, western Colorado, and central and 

northeastern Utah; in the Hilliard shale of southwestern 

Wyoming; in the Cody shale of central and western 

Wyoming; and in the Colorado shale of .Montana. The 

holotype is from the upper part of the Colorado shale 

at Chippewa Point on the Missouri River about 20 

miles below Fort Benton in Chouteau County, Mont.

Clioscaphites vermiformis (Meek and Hayden) var. toolensis 

Gobban, n. var.

Plate 19, figures 1-10

This variety differs from the typical form of the 

species in its larger size, stouter form, and greatly depressed whorls. In addition, the sculpture is not as 

pronounced and the ribbing is slightly more dense. The 

holotype has 26 primaries and 73 secondaries on the exposed whorls, with 14 primaries and 41 secondaries on 

the living chamber. Seven other specimens from the 

type locality have 13 to 19 primaries on the living chambers, averaging 15.6, and 38 to 57 secondaries, averaging 

45. The holotype is 68.5 mm. long, 62 mm. high, and 

44.5 mm. wide. Other specimens from the type locality 

range from 63 to 78 mm. in length. Probably, a few 

adults (pi. 19, fig. 9) attained the size of Scaphites depressus.

Many individuals (pi. 19, figs. 7, 8) from the Cody 

shale of southern Montana and northern Wyoming 

differ from the northern Montana specimens in possessing denser ribbing and more depressed whorls. The 

last septate whorl of some individuals is so depressed as 

to form a broad, shallow depression along part of the 

venter exactly as in the most depressed specimens of 

Scaphites depressus.

The variety resembles the form described by McLearn 

(1929, p. 77, pi. 18, figs. 1-3; pi. 19, figs. 1, 2) as Scaphites 

ventricosus Meek and Hayden var. saxitonianus in size, 

shape, stoutness, and arrangement of ribbing, but differs 

in possessing prominent tubercles and a suture with 

well-developed trifid lobes.

Holotype, U.S.N.M. 106709; paratypes, U.S.N.M. 

106710-106712.

The holotype is from a bed of calcareous concretions 

234 to 252 feet below the top of the Colorado shale, in 

the east bank of the Marias River, 11 miles southwest

of Shelby, in the WKNEtfSEJi sec. 14, T. 31 N., R. 

4 W., Toole County, Mont. The variety occurs 

with the typical form of the species at many other 

localities in Montana and Wyoming.

Clioscaphites platygastrus Cobban, n. sp. 

Plate 20, figures 12-16

The holotype is an adult shell 52.5 mm. long, 50 mm. 

high, and 28.6 mm. wide. It is tightly coiled, with 

very small umbilicus. The living chamber, of nearly 

uniform size, is entirely in contact with the septate 

coil. The venter is flattened and the flanks but 

slightly convex. . . The sculpture consists of numerous strong, sharp 

ribs and a row of high, pointed ventrolateral tubercles. 

The holotype has 90 ventral ribs and 28 primaries on 

the exposed whorls, with 70 ventral ribs and 20 primaries 

on the living chamber. On the septate coil both 

primary and secondary ribs are straight. On the living 

chamber the primaries bend slightly forward on leaving 

the umbilical wall, then curve back a little and cross 

the flanks gradually bending forward, again. Each 

primary rib terminates in a ventrolateral tubercle that 

is curved slightly back. The ventral ribs are numerous, 

strong, and straight. They are more sparse on the 

older part of the living chamber where the ventrolateral 

tubercles are largest.

The suture is moderately complex with the first 

lateral lobe transitional from bifid to trifid.

The species closely resembles Clioscaphites vermiformis in size, shape, and general sculptural features, 

but differs in the flattened venter and denser and 

stronger costation.

Holotype, U. S. N. M. 106729.

The holotype is from the upper part of the Colorado 

shale, four miles west of Sunburst, in sec. 16, T. 36 N., 

R. 3 W., Toole County, Mont.

Clioscaphites saxitonianus (McLearn) 

Plate 13, figures 1-10

1929. Scaphites ventricosus Meek and Hayden var. saxilonianus 

McLearn, Canada Nat. Mus. Bull. 58, p. 77, pi. 18, 

figs. 1-3; pi. 19, figs. 1, 2.

Shell, large, stout, and tightly coiled. McLearn 

gives 59 mm. as the length of the holotype.

The sculpture of the septate coil consists of fine, 

dense, straight ribs. On the living chamber the ventral 

ribs are coarse and sparse on the older portion and 

progressively denser toward the aperture. The primary 

ribs on the living chamber are strong and attain their 

greatest height in incipient nodes at the ventrolateral 

margin.

The suture is only moderately complex. The first 

lateral lobe is typically asymmetrically bifid but on 

advanced individuals it may be trifid.
SYSTEMATIC. DESCRIPTIONS 37

This species resembles Clioscaphites vermiformis 

va. toolensis in size, form, and general sculptural 

features, but differs in lacking pointed nodes and in 

rarely having the first lateral lobe of the suture trifid.

Holotype, Nat. Mus. Canada 9041; paratype, 

N. M. C. 9041a; plesiotypes, U.S.N.M. 106739a-b.

The holotype is from the Alberta shale of the Crowsnest River area' of southwestern Alberta. In the 

United States the species is known only from the 

Apishapa shale of southeastern Colorado, and from the 

Colorado shale, 165 feet below the top, on the east flank 

of the Sweetgrass arch of north-central Montana.

Clioscaphites saxitonianus (McLearn) var. keytei Cobban, n. yar. 

Plate 20, figures 5-7

This variety differs from the typical form by its 

much smaller size and more slender shape. The 

holotype is 42.3 mm. long, 38 mm. high, and 27 mm. 

wide. It has 20 primary ribs and 66 ventral ribs on 

the exposed whorls with 9 primaries and 29 ventral 

ribs on the living chamber.

The suture is not discernible on the type specimen. 

Most specimens in the type lot have the first lateral 

lobe asymmetrically bifid, owing to elongation of 

the dorsal branch.

The variety closely resembles small adults of Clioscaphites vermiformis, but lacks pointed nodes and the 

perfectly trifid first lateral lobe.

The variety is named for I. A. Keyte, late professor 

of geology at Colorado College, who. collected the 

type specimen. 

' Holotype, U.S.N.M. 106727.

The holotype is from a calcareous concretion in the 

Apishapa shale, 16 miles east of Trinidad, in sec. 

1, T. 32 S., R. 62 W., Las Animas County, Colo. 

The variety occurs also in the Raton Park area of 

northeastern New Mexico, and in the Colorado shale, 

.1.65 feet below the top, on the east flank of the Sweetgrass arch of .north-central Montana.

Clioscaphites novimexicanus (Reeside)

Plate 21, figures 1-9

1927. Desmoscaphites novimexicanus Reeside, U. S. Geol. Survey 

Prof. Paper 151, p. 17, pi. 11, figs. 1-4.

This species was based on. a single specimen consisting chiefly of the septate coil. The sculpture of this 

specimen consists of forwardly inclined primary ribs 

which pass half way outward from the umbilicus to the 

middle of the venter and then split into two coarse 

secondary ribs that pass straight across the venter. 

Constrictions were doubtfully reported on this specimen, but Dr. Reeside and the writer on reexamining 

the type agree that their presence cannot be demonstrated. The upper 23 feet of the Colorado shale on

the west flank of the Sweetgrass arch of north-central 

Montana has yielded scaphites that exactly fit Reeside's 

figures of this species. The Montana material includes 

some adults, permitting more complete description of 

the species.

Clioscaphites novimexicanus is characterized by its 

compressed, involute form with very narrow umbilicus, 

dense costation, and suture with trifid first lateral lobe. 

The adults at hand range in length from 38 mm. to 

76 mm.

The first whorl is broad and depressed in cross section; succeeding whorls are proportionally higher than 

the first, but all are wider than high. The umbilicus 

is wide in the first two whorls and narrow in the later 

ones. The ventrolateral margin is subangular, beginning with the third whorl at a diameter of about 2 mm. 

and continuing into or through the fourth whorl to a 

diameter of 6 to 8 mm. It is rounded at larger diameters. The living chamber begins with or after the 

sixth whorl, is relatively compressed, and is wholly attached to the septate coil. The venter is evenly 

curved in its entire length, is rounded in cross section, 

and grades uniformly into the flattened flanks. The 

umbilicus of the adult is exceedingly narrow and 

straight because of the considerable overlap by the extended flanks. The aperture is constricted, almost 

circular, and has scarcely any dorsal lappet.

The earliest three whorls are smooth. At a diameter of 3.5 mm. straight, coarse ventral ribs appear, 

ard there are about 22 ribs on the first complete whorl 

following their initial appearance. At a diameter of 5 

mm. primary ribs appear. These are curved and inclined forward as they cross the flanks, and on reachbig the margin of the venter, they become more elevated and commonly fork into two secondaries. On 

the last half of the outer septate whorl the sculpture 

changes rather suddenly from coarse rounded ribs to 

sharp narrow ribs that are more closely spaced. The 

ribbing is especially dense on the living chamber, which 

has 60 to 70 equispaced straight ventral ribs and 16 

to 20 straight primary ribs. Six or seven secondaries 

are present to each primary on the middle part of the 

living chamber. The secondaries are exceptionally 

long, extending between the primaries almost to the 

umbilical wall.

The suture is moderately complex and characterized 

by a trifid first lateral lobe. The suture is considerably simplified from its Clioscaphites montanensis 

ancestor.

Clioscaphites novimexicanus can be distinguished from 

advanced specimens of C. montanensis by its more compressed form, denser costation, and simplified suture 

with a trifid first lateral lobe. A few fragments of a 

large, stout variety (pi. 21, fig. 9) are present in the
38 SCAPHITOID CEPHALOPODS OF THE COLORADO GROUP

collections, but none are sufficiently complete to warrant description.

Holotype, U.S.N.M. 73312; plesiotypes, U.S.N.M. 

106721a-b, 106722a-b, 106723.

The holotype is from the uppermost Mancos shale, 

one mile east of head of Canyon del Yeso, Santa Fe 

County, north-central New Mexico. The species is 

common in the upper 23 feet of the Colorado shale on 

the Sweetgrass arch, north-central Montana, associated 

with Inoceramus lundbreckensis McLearn and Baculites 

thomi Reeside.

Clioscaphites? choteauensis Cobban, n. sp. 

Plate 20, figures 8-11

Shell moderately large, stout, and tightly coiled, with 

small umbilicus. Last septate whorl considerably 

depressed, with broadly rounded venter and more 

sharply rounded flanks. In side view both the venter 

and umbilical shoulder of the living chamber are evenly 

curved; in cross section the venter is well rounded, the 

flanks are flattened and round gradually into the convex, steeply sloping umbilical wall. The living chamber 

tapers slightly toward the nearly circular aperture. 

The holotype is 64.5 mm. long, 64 mm. high, and 35 

mm. wide.

The innermost whorls were not seen. The early 

part of the.last septate whorl is coarsely ribbed but 

changes abruptly to fine, dense ribbing. The ribbing 

widens on the proximal half of the living ctiamber and 

then gradually becomes denser toward the aperture. 

On most of the shell the primaries are fairly straight 

but near the aperture they become broadly curved and 

inclined forward. On the older three-fourths of the 

living chamber each primary ends as a conical ventrolateral tubercle. The ventral ribs on the living chamber are straight on the older part, but arch gently 

forward on the younger part. They extend well down 

between the primaries. Four or five are present for 

each primary on the middle part of the living chamber. 

On the exposed whorls, the holotype has 27 primaries 

and 104 secondaries with 17 primaries and 67 secondaries on the living chamber.

The suture is complex and characterized by trifid 

lobes.

The well-rounded venter, denser costation, and intercalation of secondary ribs between the primaries 

readily distinguishes this species from Clioscaphites 

vermiformis and C. platygastrus. It is a transition 

species between C. vermiformis and Desmoscaphites 

erdmanni Cobban, n. sp.

Holotype, U.S.N.M. 106728.

The holotype is from near the top of the Colorado 

shale half a mile northeast of Choteau, in sec. 19, T. 

24 N., R. 4 W., Teton County, Mont. The species

occurs also in calcareous concretions 162 feet below the 

top of the Colorado shale on the west flank of the 

Kevin-Sunburst dome in north-central Montana. Outside of those areas it is known only from the upper part 

of the Colorado shale of southwestern Montana, from 

the Mancos shale of northwestern Colorado, and from 

the Apishapa shale of eastern Colorado.

Genus DESMOSCAPHITES Reeside

Reeside (1927c, p. 16) proposed this genus with 

Desmoscaphites bassleri as the genotype to include 

moderate-sized shells with abnormal living chambers, 

early whorls having constrictions and coarse, forward 

arching ventral ribs, later whorls finer ribbed, and 

suture with a trifid first lateral lobe. The genus was 

derived from Clioscaphites vermiformis through Clioscaphites? choteauensis by acquiring constrictions in the 

internal whorls.

Desmoscaphites erdmanni Cobban, n. sp. 

Plate 21, figures 10-23

The external whorls of this species closely resemble 

those of Clioscaphites? choteauensis in size, shape, and 

general sculptural features. Desmoscaphites erdmanni 

has smaller nodes and more uniformly spaced ribs, and 

specimens comparable to C.? choteauensis in size are 

commonly more.densely ribbed.

The first two whorls succeeding the protoconch are 

wide and depressed in cross section, but later whorls 

are proportionally higher and more nearly circular. 

The umbilicus is wide in the early whorls and narrow 

in the later, with rounded umbilical shoulder. The 

flanks and venter are well rounded in the early whorls, 

but on the last septate whorl the flanks become slightly 

flattened and the venter broadly rounded. The living 

chamber is shaped like that of C.? choteauensis. The 

holotype is a nearly complete but partly crushed living 

chamber that was probably 48 mm. in length.

The early whorls are smooth. Between diameters 

of 4 and 5.5 mm. constrictions appear on the venter 

and on the outer part of the flanks. These occur in 

pairs spaced first about four and a half per whorl but 

gradually increase to six per whorl. In the early 

whorls the orad constriction is weaker than the apicad 

constriction, but in the later whorls they are equal. 

The constrictions of a pair are closely -spaced, but 

separated by a high rib. This rib and the constrictions 

bend forward on crossing the venter. At a whorl 

diameter of 8 to 10 mm. ribs first appear between the 

pairs of constrictions and cross the venter with the 

same forward swing. These ribs rapidly become 

coarse, attaining their greatest height on the venter. 

On the outer part of the flank each pair commonly 

unites into a primary rib that curves back across the
REFERENCES 39

flank, describing an arc concave forward. These 

primaries disappear at the edge of the umbilicus. At 

the beginning of the last septate whorl the coarse 

ribbing suddenly becomes fine and dense, as it does 

in C. vermiformis and C. 1? choteauensis. On the middle 

third of the living chamber the ribbing is a little sparser. 

There the primaries are long and straight and terminate in conical tubercles on the margin of the venter. 

From each tubercle two or three secondaries and one 

or two intercalated ribs cross the venter with a forward 

arching. The holotype has four secondaries to each 

primary. Fragments of larger individuals have four 

to six secondaries for each primary.

The suture is moderately complex with trifid lobes.

Demoscaphites erdmanni differs from the later D. 

bassleri Reeside in possessing fewer ribs and in having 

those on the middle third of the living chamber sparser 

than on the extremities. D. bassleri has uniformly 

spaced ribs with 6 to 9 secondaries to each primary.

The species is named for Mr. Charles E. Erdmann.

Holotype, U.S.N.M. 106724; paratypes, U.S.N.M. 

106725 a-d,

D. -erdmanni is known only from the uppermost part 

of the Colorado shale in north central Montana and 

from the upper part of the Cody shale of the Wind 

River Basin of western Wyoming. The holotype is 

from a calcareous concretion 10 feet below the top of 

the Colorado shale, 8 miles west of Shelby, in the 

NEtf sec. 31, T. 32 N., R. 3 W., Toole County, Mont., 

associated with Clioscaphites novimexicanus, Baculites 

thomi Reeside, and Inoceramus lundbreckensis McLearn.

REFERENCES

ADKINS, W. S., and WINTON, W. M., 1919, Paleontological 

correlations of the Fredericksburg and Washita formations 

in north Texas: Texas Univ. Bull. 1945, pp. 1-128, pis. 

1721, (issued 1920).

ANDERSON, F. M., 1902, Cretaceous deposits of the Pacific 

Coast: California Acad. Sci. Proc., 3d ser., Geology, vol. 2, 

pp. 1-154, pis. 1-12.

BOsE, EMIL, 1927, Cretaceous ammonites from Texas and 

northern Mexico: Texas Univ. Bull. 2748, pp. 143-350, 

pis. 1-19, (issued 1928).

COLLIGNON, MAURICE, 1928, 1929, Paldontologie de Madagasgar; 15, Les C6phalopodes du C6nomanien Pyriteux de 

Di6go-Suarez: Annales de pale"ontologie, tome 17, pp. 1-25 

(137-161), pis. 1-5 (15-19), 1928; tome 18, pp. 25-80 

(1-56), pis. 6, 7 (1, 2), 1929.

FRECH, FRITZ, Ueber Scaphites, 1915, I: Centralbl. Mineralogie,

Jahrg. 1915, no. 21, pp. 553-568, 14 figs. 

GEINITZ, H. B., 1874, Das Elbthalgebirge in Sachsen; Theil 2,

Der mittlere und obere Quader, 5, Gasteropoden und

Cephalopoden: Palaeontographica, Band 20, pp. 120-199,

pis. 31-36. 

LEONARD, R., 1897, .Die Fauna der Kreideformation in Oberschlesien: Palaeontographica, Band 44, pp. 11-70, illus. 

MCLEARN, F. L., 1929, Cretaceous invertebrates; Mesozoic

paleontology of Blairmore region; Alberta: Canada Nat.

Mus. Bull. 58, pp. 73-79, pis. 13-19. 

MEEK, F. B., 1876, Invertebrate Cretaceous and Tertiary

fossils of the upper Missouri country: U. S. Geol. Survey

Terr. Rept., vol. 9, pp. 1-629, illus. 

MEEK, F. B., and HAYDEN, F. V., 1862, Descriptions of new

Cretaceous fossils from Nebraska Territory, collected by

the expedition sent out by the Government under the command of Lieut. John Mullan, U. S. Topographical Engineers,

for the location and construction of a wagon road from the

sources of the Missouri to the Pacific Ocean: Acad. Nat.

Sci. Philadelphia Proc. 1862, pp. 21-28. 

MOREMAN, W. L., 1942, Paleontology of the Eagle Ford group of

north and central Texas: Jour. Paleontology, vol. 16, no.

2, pp. 192-220, pis. 31-34, 2 text figs. 

MORROW, A. L., 1935, Cephalopods from the Upper Cretaceous

of Kansas: Jour. Paleontology, vol. 9, no. 6, pp. 463-473,

pis. 49-53, text figs. 1-8. 

PICTET, F. J., and CAMPICHE, G., 1861-1864, Description des

fossiles du terrain cr6tac6 des environs de Sainte Croix, pt.

2: Materiaux pour la palfiontologie suisse, ser. 3, Mon. 2,

pp. 1-752, pis. 44-98. 

REESIDE, J. B., Jr., 1927a, Cephalopods from the lower part

of the Cody shale of Oregon Basin, Wyoming: U. S. Geol.

Survey Prof. Paper 150-A, pp. 1-10, pis. 1-8.

 , 1927b; The scaphites, an Upper Cretaceous ammonite 

group: U. S. Geol. Survey Prof. Paper 150-B, pp. 21-40, pis. 

9-11.

 , 1927c, The Cephalopods of the Eagle sandstone and 

related formations in the western interior of the United 

States: U. S. Geol. Survey Prof. Paper 151, pp. 1-87, pis. 

1-45.

SCHLUTER, CLEMENS, 1872, Cephalopoden der oberen deutschen 

Kreide: Palaeontographica,, Band 21, pp. 1-120, pis. 1-35.

SPATH, L. F., 1923-19.43, A monograph of the Ammonoidea of 

the Gault: Palaeont. Soc. Mon., pp. 1-783, illus.

WARREN, P. S., 1930, New species of fossils from Smoky River 

and Dunvegan formations, Alberta: Alberta Research 

Council Geol. Survey Rept. 21, pp. 57-68, pis. 3-7.

 , 1947, Cretaceous fossil horizons in the Mackenzie River 

valley: Jour. Paleontology, vol. 21, no. 2, pp. 118-123, pis. 

29, 30.

YABE, H., 1910, Die Scaphiten aus der Oberkreide von Hokkaido: Beitr. Palaontologie Oesterr.-Ungarns u. des Orients, 

vol. 23, pp. 159-174, pi. 15.

INDEX

[Italic numbers indicate descriptions.]

Abstract.................................................................'..... i

Acknowledgments....-.-------------.--_-...-------.-------------_-_-----_--. 2

aeyudlis, Scaphiies............................................................ 0,18

ainuanus, Yesoites..............................:............................. 29

aqiMacnsis, Scaphiies..... .............._.................................... 10

arcadiensis, Scaphites.......................................'..... 2,3, 4, 7, £1, 22 pi. 2

urtilobtis, Scaphites preveutricosus........................................... 87, pi. 8

auriculatus, Scapltites......................................... 2,3,5, 7,9,SO,33, pi. 10

auritus, ScaphUes............................................................. 31

B 

naculitesasper................................................................ 33

codyensis......................................... ..........._..__.... 33,34

thomi..................................................................... 38,39

bassleri, J)esmoscaphites..................................................... 9,10,39

bighornensts, Scaphites comensis...... .................................... 26.82, pi. 7

binneyi, ScaphUes................................................... 2,7, 10, 38, pi. 14

bosffweytsfa, Scaphites.......................................................... C

hrf«em«?isi«, ScaphUes......................................................... 6,18

Cnrlilo shalo_...__......................................................... 4,5

carlilensis, Scaphiies................................................ 2,4,5,7,2/,pl. 2

c/iotea«e(tste, Clioscaphit.es ................................. 2,4, 5, G, 7,10.38, 39, pi. 20

circularis, Scaphites....-..............................................:....... 6

Clioscaphites.................................................................. 2,34

choteauensis.................................. ......... 2,4, 5,6, 7,10,38,39, pi. 20

montanensis....................... 2, 3,5,6, 7,8,9,10.11. 34, 35,36.37, pis. 16,17, 20

hesperhts................................................... 33, 34, pis. 16,17

noeiinexicanus............................... 2,3,5,6,7,8,9,10,11,34,37,39,pi. 21

platygastrua............................................... 2,4, 7,10,36,38, pi. 20

soxitonianus................................................... 2, 5, 7, 9,3(7, pi. 13

keytet.............................................................. 37, pi. 20

vermiformis.................................. 2,3, 5, 7,10,34,35,36,37,38,39, pi. 18

toolensis.. .................................................... 3,35,37.pi. 19

codyensis, Baculiles........................................................... 33,34

Collignoniceras hyatti.......................................................... 21

woollgari.................................................................. 20

coloradensis, Scaphites......... ................................ 2,3,5,7,9,S3,34,pi. 18

Colorado shalo................................................................ 5

co'rtrfoni, ScaphUes............................................................. 29

corcewsis, Scaphites............................................... 2,4,' 5, 7,9,25, pi. 7

bighornensis, Scaphites........... .................................... £6,28,pi. 7

D 

delicutulus, Scaphites................................................. 2, 3,.5,6, 7,9,18

delicatulus greenhornensis, Scaphiies.................................... 6,18,30, pi. 1

depressus, ScaphUes................................... 2, 3.6, 7,8,9,11,30,35,36, pi. 15

ScaphUes ventricosus...................................................... 32

depressus oregoriensis, Scaphiies........................................... 9,33,34,36

depressus stantoni, ScaphUes.......................................... 9,S3,34, pi. 15

Desmoscaphites............................................................... 2,38

bassleri................................................................. 9,10,39

erdmanni................................................ 2,4,5,7,10,34,38, pi. 21

novimcxkanus............................................................. 37

dimidius, Inoceramus.......................................................... 23

erdmanni, Desmoscaphites.................................... 2,4,5,7,10,34,38, pi. 21

erucoides, ScaphUes impendicoslaius........................................ 89, pi. 11

Evolution of the Scaphites............... -.........-.......-...-.---.--....--. 6-11

exogyroides, Inoceramus....................................................... 31

ferronensis, Scaphites......................................... 2, 5,7,9,23,24, 25, pi. 4

Form and general characters...................---.....---.....-......---....- 3

fragilis, Inoceramus........................................................... 20

Jrontierensis, Scaphites............................................... 2,3,9,SO,pi. 10

G 

geinitzi, Scaphiies......................................................... 18,19,20

graclle, Sciponoceras........................................................... 6

gracillistriatus, Scaphites mariasensis........................................ 88, pi. 8

Greenhorn formation...--..--...-.---..--....----.------.--.-.-..- ----.... 5

greenhornensis, Scaphites delicatulus.................................... 6,/8,30,pl. 1

H ' Page 

haydeni, Scaphites warreni.................................................. 23,pi. 3

hesperius, Clioscaphiies montanensis................................. 33, 34, pis. 16,17

hilli, Scaphites................................................................ 6

hippocrepis, ScaphUes......................................................... 10,34

Holcoscaphif.es................................................................. 2

larvaeformis............................................................... 19

vermiformis............................................................... 35

warreni...................................1............................... 22

hugardianus, Scaphites........................................................ 20

hyatti, CoUignoniceras........................ .................._____._. 21

impendicostatus, Scaphites.__............................ 2,3,5,7,9,10,28,32, pi. 11

impendicoslatus erucoides, ScaphUes......................................... 89, pi. 11

Inoceramus dimidius.....-.............-..------...........-.....'---.......... 28

exogyroides................................................................. 31

fragilis..... ...................__.__................__.........__ 20

lundbreckensis............................................................. 38,39

umbonatus.-.............................................................. .31, 32

undabundus............................................................... 31

interjectus, ScaphUes.................................................2,10,32, 34, pi. 14

ScaphUes ventricosus.........:............................................. 32

K 

keytei, Clioscaphites saxitonianus............................................ 37, pi. 20

lamberti, ScaphUes........................................................^.... 29

larvaeformis, 1-Jolcoscaphites......................................:............. 19

ScaphUes---....-..-.......-...-.-.-.............. 2,3,5,6, 7,11, 19, 20, 21. 22, pi. 1

larvaeformisobesus, Scaphites-............................................... £0,pi. 1

leei, Scaphites........................................................ 5,10,34, pi. 21

Localities, list, descriptions_...-..----..--.....--.....--..-..-..-.-....--.-. 13-18

map showing..----.--.....-.--.--.-...---.....-...-.----..-'.-......._.. 12

' undbreckensis, Inoceramus.................................................... 38,39

M 

macombi, Prionocyclus......................................................... 23

mariasensis, Scaphites............................................. 2, 5,6,7,9,£'8, pi. 8

mariasensis gracillistriatus, Scaphites----..................................... 28, pi. 8

meeki, ScaphUesnigricollensis............................................... 26,pi. 5

minutus, ScaphUes...........................................i................ 23

montanensis, Clioscaphites............... 2,3,5, 6, 7,8,9,10,11,34, 35,36,37, pis. 16,17,20

montanensis hesperius, Clioscaphites................................^... 34, pis. 16,17

morrowi, ScaphUes...........-.......'..................................-.... 2,21, 22

N 

nigricollensis^ScaphUes..-.....-.....----....-.-...... 2, 3,4, 5, 6,7,9,11,25, 26, pis. 6,7

nigricollensis meeki, ScaphUes..-...-.--....--.......-.-......-....-----..... 26, pi. 5

Niobrara formation.............^......................................i....... 4-5

shale----.--------------.....------..------.---.------------------------.. 6

novimexicanus, Clioscaphites...................... 2, 3,5,6, 7,8,9,10,11,34,37,39,pi. 21

Desmoscaphites........................................................... 37

obesus, Scaphiies larnaeformis............................................... 20, pi. 1

oregonensis, -ScaphUes depressus........................................... 9,33,34,36

patulus, ScaphUes............................................. 2,3,5, 6, 7,20. 21, pi. 1

perrini, ScaphUes............................................................. 31

pisinnus, Scaphites................................................ 4,7,9,25,31,pi. 5

planus, Yezoites............................................................... 29

plotygastrus, Clioscaphites...................................... 2,4,7,10,36,38,pi. 20

praecoquus, Scaphites..-....,.-.....-.-...-..-....-.........- 2,3, 5,6, 7, 9,11,20, pi. 1

preventricosw, Scaphites............................ 2, 5,6.7,8,9,11,26,28,29.31, pi. 9

preventricosus artUobus, ScaphUes............................................ 27, pi. 8

preventricosus sweetgrassensis, Scaphites................................. 27, 28, pi. 10

Prionocyclus macombi..................^...................................... 23

wyomingensis............................................................. 24

pseudoaegualis, Scaphites...................................................... 29

puerculus teshioensis, Scaphites.-.............................................. 31

pygmaeus, ScaphUes........................................................... 21

41
42 SCAPHITOID CEPHALOPODS OF THE COLORADO GROUP

Rceside, John B., Jr., quoted.

Page

'2

Sage breaks member _ ......_ _ ._..._----_---_..-...._____.__._____________ 4

sagensis, Scaphites.... ... .............................................. 2, 9, SO, pi. 10

saxitonianus, Clioscaphites __ -.---.----.-.--.-..-----.-........... .2, 5, 7, 9, 36, pi. 13

Scaphites ventricosus .....:................................................ 36

saxitonianus keytei, Clioscaphites .... ............. ... ........................ 37, pi. 20

Scaphites aequalis. ...... . ........ . ..... . .... .............. .... . .... .... ... . ... 6,18

Scaphites aguilaensis ...... ... ... ... ........................................... 10

arcadiensis.. ....... . ... ... ... . ............. .. ... ........ ..... 2, 3, 4, 7, 21 , 22, pi. 2

auriculatus.. ......... . ... . ...... ........... ..... . ... . ..... 2, 3, 5, 7, 9, SO, 33, pi. 10

auritus ...... . ..... . ... .................................................... 31

binneyi....... .................................................. 2, 7, 10, S3, pi. 14

bosquensis ..... . ... .............. J......... ... .................. ... ........ 6

brittonensis ... ' ... ...................... ... ................................. 6,18

carlilensis ... ................................... ... .............. 2, 4, 5, 7, 21, pi. 2

circularis ...... ......................... ... ................... ... .......... 6

coloradensis . .... . ...... ...... ...... .............'. ___ '... 2, 3, 5, 7, 9, S3, 34, pi. 18

condoni. .... ... ...................................... ... ....... ............ 29

corvensis.. ... ............^.. ................ ......1........... 2, 4, 5, 7, 9, 86, pi. 7

bighornensis. ...... .... ... .... ... ........... ... . ...... .... ........ 26, 28, pi. 7

delicatulus.... ................................................... 2,3,5,6,7,9,18

greenhornensis.. ............................................... 6,18, 30, pi. 1

depressus.. ....................................... 2, 3, 6, 7, 8, 9, 11, 32, 35, 36, pi. 15

oregonensis.. ................ . ........... . ... .... ................. .9,33,34,36

Stantoni. ...................................................... 9, 33, 34, pi. 15

jenonensis. ............................................... 2, 5, 7, 9, 23, 24, 25, pi. 4

frontierensis..... .... ............. ..... . ..... ....- ... . ...... ....... 2, 3, 9, 30, pi. 10

geinitzi- ............. . .... . ..... ....... ... . ... . ....... ..... ....... .." _ 18,19,20

hilli....... ................................................................ 6

hippocrepis. ............ ... ..........-...........-..........^.... ... ...... 10,34

hugardianus ..... ---------------------------- ... ... ........................ 20

impendicostatus ... . ....... . ... ...... ..... . ...... ....... 2, 3, 5, 7, 9, 10,28, 32, pi. 11

. erucoides ... .................'....................................... 20,pl.ll

interjectus.......:.....................-.........-.-...-.-.-.-.- 2, 10, 32, 34, pi. 14

lamberti ...... ............:...........-....... ... .......... ... ..... .... ... . 29

. larvaeformis... ...... ............................ 2, 3, 5, 6, 7, 11, 19, 20, 21, 22, pi. 1

obesus....... ... ...............^..... ............................... SO, pi. 1

leei. .............................................................. 5, 10,34, pi- 21

mariasensis...-!--- ............................................ 2, 5, 7, 9,28, pi. 8

gracillistriatus. ----------------------------------------------------- 28, pi. 8

minutus. ......... ... ............................................ ... ...... 23

morrowi.. ...... _______ ------- __________________ .. 2,21,22

nigricollensis. ... ..... ......... . ................. 2,3,4,5,6,7,9, 11, 25, 26, pis. 6, 7

meeki .... . ... . ........ .... ..... ....... ... ... ......... -------- _ .-- 26, pi. 5

paiwZws..--- ----------------------------------------------- 2, 3,5, 6, 7,20, 21 pi. 1

perrini ... ............................... ... ............................... 31

pisinnus ....... ..... ........ . ..... ................ ... . ......... .. 4, 7, 9, 2fi, pi. 5

praecoswws..-----------------------'.. ------------------- 2, 3,5, 6, 7, 9, 11,20, pi. 1

preventricosus... ............................... 2, 5, 6, 7, 8, 9, 11,26, 28, 29,31, pi. 9

artilobus ... .... ... . .... .. ... . ..... ------------ _ ------ ________ 27, pi. 8

sweetgrassensis-.-l--------------.--- ... ......... .... . ... ....... 27, 28, pi. 10

pseudoaegualis......... ........ ... ... ... ... ......... ... ............. ... ... 29

puerculusieshioensis...-----------. --------------------------------------- 31

----------------------------- ---------------------1---- - 21

-. ------------------------------------------------------- 2, 9, 30, pi. 10

subevolutus ..... --------------------------------- -'---------.---- -------- 6

tetonensis. ............................................. 2, 3,5, 7, 10, 31,32, pi. 14

uintensis............................ ............---...-.-.... 2, 3, 9, 29, 30, pi. 10

ventricosus.... ...................... 2, 3, 5, 6, 7, 8, 9, 11, 27, 31, 32, 33, pis. 12, 13

depressus.. ...................... ... ... --------------------------- 32

interjectus .... --------------------------- ---- ------------ .- 32

saxitonianus. . . . . ... .............. ... ........'....... ... ... ... ...... ... 36

vermiformis. ...... . ......... .... ... . - 32,35

veterinovus. .... ..................... .^........ .............. 2,4, 7, 9, 23, 25, pi. 3

Scaphites aguilaensis Continued Page 

warreni......................................... 2, 4, 5, 7, 9,10,11, SI, 23, 24, pi. 3

haydeni......................... ________ 23, pi. 3

sttesiaca....................................................... 23, 24, 25, 29

ubiquitosus...................-...-...............................23, pis. 3, 4

wyomingensis......................................................... 22, 24

whUfiadi...................................... 2, 3, 4, 5, 7, 9, 10,24, 25, 26, pis. 4, 5

wyomingensis............................................................. 24

yonekurai................................................................. 20, 29

Sciponoceras gracile........................................................... 6

Sculpture______________________________....______ 3

silesiaca, Scaphites warreni.............................................. 23,24,25, 29

Size, range____..--_---...--.'----.-.-........_..........._._..... 3

stantoni, Scaphites depressus.......................................... 9,33,34, pi. 15

subevolutus, Scaphites......................................................... 6

Suture___ ^.............................................................'.... 4

Sweetgrass arch_......_...._-_-.._._._________.........._.....__ 5

sweetgrassensis, Scaphites preeentricosus................................. 27, 28, pi. 10

T 

teshioensis, Scaphitespuerculus................................................ 31

tetonensis, Scaphites......................................... 2,3,5,7,10,37,32, pi. 14

Texanites shoshonensis.......-..-............................................. 33

thomi, Baculites............................................................... 38,39

Vascoceras................................................................ 19

toolensis, Clioscaphites vermiformis.................................... 3,35,37, pi. 19

Turner sandy member_..................._--_._-_._._.__.__._.._ 4

U 

ubiquitosus, Scaphites warreni............................................ 23, pis. 3,4

uintensis, Scaphites............................. ..........'........ 2,3,9,29,30, pi. 10

umbonatus, Inoceramus--------...------------_-.._.____--------_.__.. 31,32

undabundus, Inoceramus....-...-.-..-.-.-.......-.-.-.-.-.-.-................ 31

V 

Variation...--------.-._____---.----_--__.._............ __...--.... 4

Vascoceras thomi.............................................................'. 19

ventricosus, Scaphites.............------.--.. 2, 3,5, 6, 7,8,9,11, 27. 31, 32, 33, pis. 12,13

ventricosus depressus, Scaphites................................................ 32

ventricosus interjectus, Scaphites.-- __________________________ 32 

ventricosus saxitonianus, Scaphites............................................. 36

vermiformis, Clioscaphites........................ 2,3,5,7,10,34,35,36,37,38,39, pi. 18

Holcoscaphites............................................................ 35

Scaphites.......................................________________ 32,35

vermiformis toolensis, Clioscaphites.................................... 3,36,37, pi. 19

veterinovus, Scaphites..-.......--------------__._------------ 2,4,7,9,23,25, pi. 3

W 

warreni, Holcoscaphites...... __--------- ............_.. 22

Scaphites......................................... 2, 4, 5,7,9,10,11. 21, 23, 24, pi. 3

warreni haydeni, Scaphites.................................................. 23, pi. 3

warreni silesiaca, Scaphites.................................................... 23,24

warreni ubiquitosus, Scaphites............................................ 23, pis. 3,4

warreni wyomingensis, Scaphites............................................... 22, 24

whitfieldi, 'Scaphites................................. 2, 3,4, 5, 7,9,10, 24, 25, 26, pis. 4, 5

woollgari, Collignoniceras...---------------- -----------_.._-__.._..... 20

worthense, Worthoceras........................................................ 6

Worthoceras worthense_..----.. .-.. -... .-.- --------_ - 6

wyomingensis, Prionocyclus........................:.......................... 24

Scaphites..........^...................................................... 24

wyomingensis, Scaphites warreni............................................... 22

Y 

Yezoites ainuanus...---------------------------------------------------------- 29

planus..................................:................................. 29

yonekurai, Scaphites............................................................ 20,29

Z 

Zones based on scaphite occurrence-.-.-. ....----.-.-.-.-.. ------------- 4,5

o
PLATES 1-21
PLATE 1

[All figures natural size except as indicated on plate]

FIGURES 1-3. Scaphites delicatulus Warren var. greenhornensis Cobban, n. var. Bottom, top, and side views of holotype, an internal 

mold, U.S.N.M. 106766. From a limestone concretion 10 feet below top of Greenhorn formation at map locality 

101 (p. 18).

4-15. Scaphites larvaeformis Meek and Hayden. 4-7, Third suture from last, and side, top, and bottom views of holotype, 

U.S.N.M. 229. From Carlile shale of eastern flank of Black Hills. 8-12, Side, front, rear, top, and bottom views 

of a specimen retaining most of the shell, U.S.N.M. 106743. From a limestone concretion in the basal part of 

Carlile shale at map locality 129. 13, Next to last suture of an incomplete specimen, U.S.N.M. 106744. From a 

limestone concretion 12 feet above base of Carlile shale at map locality 102. 14, 15, Side and front views of a small 

internal mold at diameter of 4 mm., U.S.N.M. 106745. From a limestone concretion near base of Carlile shale 

at map locality 137 (p. 19).

16-22. Scaphites larvaeformis var. obesus Cobban, n. var. 16-21, Side, front, rear, top, and bottom views, and last suture of 

holotype, U.S.N.M. 106767. From a limestone concretion near base of Carlile shale at map locality 124. 22, 

Cross section at diameter of 17 mm. of septate whorls of an incomplete specimen, U.S.N.M. 106768, from same 

locality as figures 14, 15 (p. 20).

23-32. Scaphites patulus Cobban, n. sp. 23-25, Bottom, top, and side views of an incomplete, small, slender, paratype, 

U.S.N.M. 106771, from same locality as figures 16-21. 26-31, Side, front, rear, top, and bottom views, and cross 

section through middle of curved part of living chamber of holotype, U.S.N.M. 106796. From a limestone concretion near base of Carlile shale at map locality 121. 32, Side view of the largest known specimen, U.S.N.M. 

106770, from same locality as figures 26-31 (p. 20).

33-36. Scaphites praecoquus Cobban, n. sp. Bottom, top, rear, and side views of holotype, U.S.N.M. 106758, from same locality 

as figures 14, 15 (p. 20).
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SCAPH1TES OF THE COLORADO GROUP

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31
PLATE 2

[All figures natural size except as indicated on plate]

FIGURES 1-8. Scaphites arcadiensis Moreman. 1, 2, Side and bottom views of an incomplete living chamber, as internal mold, 

U.S.N.M. 106765b. From a ferrugittous-concretion-bed 57-81 feet above base of Carlile shale at map locality 103. 

3, 4/''Side and rear views of an internal mold of a living chamber, U.S.N.M. 106765c, from the same locality. 5-8, 

Nexii'to ;last(Sutur.o, and side, top, and bottom views of a specimen retaining part of the shell, ,U.S.N.M. 106765a,, 

froirf the"same locality (p. 21). 'J * _ .. * 

9-23. Scaphites carlilensis&Morrow. 9-11, Twelfth from last suture," and"bottom and side views of a,.small,. slender specimen retaining part of the shell, U.S.N.M. 106742a, from same locality as figures" 1, 2. 12-1:^7, Side^froht, rear, 

top, and bottom views, and second from last suture of an internal mold retaining part of .the .$hell; U.S.N.M;. .! 

106742b, from same locality as figures 1, 2. 18, Fourth from last suture of an adult specimen", U.S.N'.M. 106740. 

From a concretion found in the upper part of the Blue Hill shale member of the Carlile shale at map locality 268. 

19-21, Fifth from last suture, and side and rear views of an internal mold of the septate whorls and beginning of 

the living chamber of the largest known specimen from the Black Hills, U.S.N.M. 106742c, from same locality as 

figures 1, 2. 22, 23, Rear and side views of the internal mold of a large living chamber, U.S.N.M. 106741, from the 

same locality as figures 1, 2 (p. 21).
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SCAPHITES OF THE COLORADO GROUP
PLATE 3

[All figures natural size except as indicated on plate]

FICURES 1-7. Scaphites veterinovus Cobban, n. sp. From a calcareous concretion 14.5 feet above base of Turner sandy member 

of Carlile shale at map locality 108. 1-6, Side, top, and bottom views of holotype, U.S.N.M. 106763. 7, Next to 

last suture of paratype, U.S.N.M. 106764 (p. 23).

8-21. Scaphites warreni Meek and Hayden. 8, Second from last suture of a specimen, U.S.N.M. 106750, from a calcareous 

concretion 36 feet above base of Turner sandy member of Carlile shale at map locality 109. 9-12, Side, rear, top, 

and bottom views of a specimen, U.S.N.M. 106746, from same locality as figures 1-7. 13, Side view of holotype, 

U.S.N.M. 225. From the Carlile shale at map locality 125. 14, Cross section at diameter of 21.5 mm."through 

the septate whorls of an adult specimen, U.S.N.M. 106747. From a thin sandstone bed in the Mancos shale 150 

feet below the Tocito sandstone lentil at map locality 274. 15-20, Front, rear, side, bottom, and top views, and 

third from last suture of an internal mold, U.S.N.M. 106748, from same locality as figure 14. 21, Fourth from 

last suture of a specimen, U.S.N.M. 106749, from the Frontier formation at map locality 231 (p. 21).

22-25. Scaphites warreni var. haydeni Cobban, n. var. Next to last suture, and rear, bottom, and side views of holotype, 

 U.S.N.M. 106761. From same locality as figure 21 (p. 23).

26, 27. Scaphites warreni var. ubiquitosus Cobban, n. var. Side and rear views of an incomplete adult living chamber retaining part of the shell, U.S.N.M. 106754. Associated with the type of the species (p. 23).
OEOLOGICAb StTRVEY PROFESSIONAL PAPER 23» PLATE 3

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SCAPH1TES OF THE COLORADO GROUP
PLATE 4

[All figures natural size except as indicated on plate] :

FIGURES 1-15. Scaphites warreni var. ubiquitosus Cobban, n. var. 1-5, Side, rear, top, and bottom views, and second from last 

suture (composite) of holotype, an internal mold, U.S.N.M. 106751. From a thin sandstone bed in the Mancos 

shale about 150 feet below base of Tocito sandstone lentil at map locality 274. 6-11. Seventh from last suture, 

and top, bottom, rear, front, and side views of an internal mold, U.S.N.M. 106752, from same locality as figures 1-5. 

12-15, Last suture, and bottom, rear, and side views of an internal mold of a small adult specimen, U.S.N.M. 

106753. From the Mancos shale at map locality 273 (p. 23).

16-29. Scaphites ferronensis Cobban, n. sp. 16-19, Third from last suture, and bottom, rear, and side views of holotype, an 

internal mold, U.S.N.M. 106759. From the Ferron sandstone member of Mancos shale at map locality 236. 20-25, 

Third from last suture, and side, front, rear, top, and bottom views of a slender paratype, an internal mold retaining 

part of the shell, U.S.N.M. 106760a, from same locality as holotype. 26-29, Side, rear, bottom, and top views of a 

stout paratype, an internal mold, U.S.N.M. 106760b, from same locality as holotype (p. 23).

30-40. Scaphites whitfieldi Cobban, n. sp. 30-34, Fifth from last suture, and side, rear, bottom, and top views of holotype, 

U.S.N.M. 106735. From a ferruginous concretion bed 251-264 feet above base of Carlile shale at map locality 112. 

35-40, Side, front, rear, top, and bottom views and next to last suture of a specimen, an internal mom, U.S.N.M. 

12258a, figured by Whitfield as S. wyomingensis Meek. From the Carlile shale on the western flank of the Black 

Hills (p. 24).
GEOLOGICAL SURVEY PROFESSIONAL PAPER 239 PLATE 4

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SCAPHITES OF THE COLORADO GROUP
PLATE 5

[All figures natural size except as indicated on plate]

FIGURES 1-4. Scaphites whitfieldi Cobban, n. sp. 1, Fragment, retaining most of the shell, from the straight part of the living chamber 

of the largest known specimen, U.S.N.M. 106738a. From a ferruginous concretion bed 251-264 feet above base of 

Carlile shale at map locality 112. 2, Cross section through the septate whorls at diameter of 16.5 mm. of an incomplete specimen, U.S.N.M. 106737. From "a calcareous concretion 43 feet above base of Turner sandy member 

of Carlile shale at map locality 126. 3, Second from last suture of an internal mold, U.S.N.M. 106736. From a 

ferruginous concretion in Turner sandy member of Carlile shale at map locality 136. 4, Fragment of a sandy, ferruginous concretion containing numerous specimens of S. whitfieldi, U.S.N.M. 106738b, from same locality as figure 1 

(p. 24). 

5-8. Scaphites pisinnus Cobban, n. sp. Bottom and side views, and sixth from last suture of holotype, an internal mold

retaining part of the shell, U.S.N.M. 106762. From same locality as figure 1 (p. 25).

9-26. Scaphites nigricollensis var. meeki Cobban, n. var. From a calcareous concretion bed 59 feet below top of Turner 

sandy member of Carlile shale at map locality 114. 9, Cross section through septate whorls at diameter of 16.5 mm. 

of a complete specimen, U.S.N.M. 106734b. 10-14, Second from last suture, and bottom, top, rear, and side views 

of holotype, U.S.N.M. 106733. 15-20, Side, front, rear, top, and bottom views, and next to last suture of an internal 

mold, U.S.N.M. 106734a. 21, Second from last suture of an internal mold of an adult specimen, U.S.N.M. 106734d. 

22-26, Bottom, top, rear, and side views, and next to last suture of a large specimen retaining some of the 

shell, U.S.N.M. 106734c (p. 26).
GEOLOGICAL SURVEY PROFESSIONAL PAPER 239 PLATE 5

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SCAPHITES OF THE COLORADO GROUP

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PLATE 6

[All figures natural size except as indicated on plate]

FIGURES 1-17. Scaphites nigricollensis Cobban, n. sp. From a bed of calcareous concretions 59 feet below top of Turner sandy 

member 6f Cariile'^hale at map locality 114. 1-6, Bottom, top, rear, front, and side views, and second from last 

suture of holotype^aii ; internal mold, U.S.N.M. 106730. 7-12, Next to last suture, and front, rear, top, bottom, 

and-iside views of a paratype, an internal mold, U.S.N.M. 106731b. 13-17, Fifth from last suture, and side, rear, 

top and bottom views of a paratype, an internal mold, U.S.N.M. 106731a (p. 25).
GEOLOGICAL SUHVEY PKOPESSIONAL PAPER 239 PLATE 6

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SCAPHITES OF THE COLORADO GROUP

17
PLATE 7

[All figures natural size except as indicated on plate]

FIGURES 1-5. Scaphites nigricollensis Cobban, n. sp. 1-3, Bottom and side views, and second from last suture of an internal mold, 

ILS.N.M. 106732; From Carlile shale at map locality 133. 4, About tenth from last suture of a paratype, U.S.N.M. 

10j>731d. From a calcareous concretion-SU-feet below top of Turner-sandy member -of -Carlile shale -at map locality 

114. .5, Cross Section of septate whorles of an incomplete specimen, U.S.N.M. 106731c, from same locality as figure 4

(P. 25). ;<.

6-10. Scaphites corvensis. Cobban, n. sp. Side, rear, and bottom views, c.ros^.section^through straight part of living chamber, 

and next to last suture of holotype, an internal mold retaining pjart*bf the shjjll, U.S.N.M. 106756. From a calcareous 

concretion 180 feet above base of Carlile member of Cody shale at map locality 95 (p. 26). .' ; 

11-17. Scaphites corvensis var. bighornensis Cobban, n. var. Next''to last suture, side, front, rear, top, and bottom views, 

and cross section through straight part of living chamber of holotype, an internal mold, U.S.N.M 106756. From 

same locality as figures 6-10 (p. 26).
GEOLOGICAL SURVEY PROFESSIONAL PAPER 239 PLATE 7

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SCAPHITES OF THE COLORADO GROUP

16

17
PLATE 8

[All figures natural size except as indicated on plate]

FIGURES 1-6. Scaphites preventricosus Cobban var. artitobus Cobban, n. var. Bottom, top, rear, front, and side views, and next to 

last suture (composite) of holotype, U.S.N.M. 106680. From a ferruginous concretion bed 617-634 feet'below top 

of Colorado shale at map locality 34 (p. 27).

7-13. Scaphites mariasensis Cobban var. gracillistriatus Cobban, n. var. 7-11, Side, rear, bottom, and top views, and second 

from last suture of holotype, an internal mold, U.S.N.M. 106682. From same locality as figures 1-6. 12, 13, Side 

and front views of an immature specimen with nearly complete living chamber, U.S.N.M. 106683, from the same 

locality (p. 28).

14-17. Scaphites mariasensis Cobban, n. sp. Last suture, and bottom, rear, and side views of holotype, an internal moW, 

U.S.N.M. 106681. From same locality as figures 1-6 (p. 28).
GEOLOGICAL SURVEY PROFESSIONAL PAPER 239 PLATE 8

15

SCAPHITES OF THE COLORADO GROUP
PLATE 9

[All figures natural size except as indicated on plate]

FIGURES 1-16. Scaphites preventricosus Cobban, n. sp. 1-4,-Side and front views of internal whorls at diameter of 11.8 mm. of a 

specimen retaining most of the shell, ILS.N.M. 106676d. From a bed of calcareous concretions 514-525 feet 

''. below top of Colorado shale at map locality 35. 5, Side view of the earliest whorls of a specimen at [diameter 

of 2.8 mm., U.S.N.M. 106676a, from the same'locality. 6-8, Front and side views, and last suture'of an immature 

specimen with most of the living chamber, U.S.N.M. 106676c, from the same locality. 9, Cross section through 

septate whorls at diameter of 32.5 mm. of an incomplete specimen, U.S.N.M. 106679. From a bed of calcareous 

concretions in the Colorado shale 202-207 feet above top of a calcareous member of Greenhorn age at map locality 

48. 10, Cross section at diameter of 4 mm. of an immature specimen, U.S.N.M. 106676b, from same locality as 

figures 1-4. 11-16, Sixth from last suture, and front, rear, side, top, and bottom views of holotype, an internal 

mold, U.S.N.M. 106675, from same locality as figures 1-4 (p. 26).
GEOLOGICAL SURVEY PROFESSIONAL PAPER 239 PLATE 9

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14 15 16

SCAPHITES OF THE COLORADO GROUP
PLATE 10

[All figures natural size except as indicated on plate]

FIGURES 1-4. Scaphites frontierensis Cobban, n. sp. Side, rear, and bottom views of holotype, an internal mold, U.S.N.M. 106704.

From a sandstone bed 180 feet below top of Frontier formation at map locality 180 (p. 30). 

5, 6. Scaphites uintensis Cobban, n. sp. 5, First lateral lobe and part of adjoining saddles of last suture of paratype,

U.S.N.M. 106703. From the Mancos shale 180 feet above top of Frontier sandstone member at map locality 248.

6, Side view of an artificial cast made from the holotype, an impression in shale, U.S.N.M. 106702, from same

locality as figure 5 (p. 29). 

7-10. Scaphites sagensis Cobban, n. sp. 7, 8, Bottom and side views of holotype, a distorted specimen retaining part of the

shell, U.S.N.M. 106696. From upper part of Frontier formation at map locality 195. 9, 10, Rear and side views

of the internal mold of an incomplete living chamber, U.S.N.M. 106697. From upper part of Frontier formation

at map locality 196 (p. 30). 

11-17. Scaphites auricutatus Cobban, n. sp. 11-16, Side, rear, bottom, and top views, and last suture of holotype, an internal

mold retaining part of the shell, U.S.N.M. 106684. From a bed of calcareous concretions 514-525 feet below top of

Colorado shale at map locality 35. 17, Cross section through the septate whorls and living chamber of an adult

specimen, U.S.N.M. 106685, from the same locality (p. 30). 

18-25. Scaphites preventricosus Cobban var. sweetgrassensis Cobban. 18-20, Side and bottom views, and fourth from last

suture of a small internal mold retaining some of the shell, U.S.N.M. 106678, from same locality as figures 11-16.

21-25, Second from last suture, and side, front, top, and bottom views of holotype, an internal mold, U.S.N.M.

106677, from the same locality (p. 27).
GEOLOGICAL SURVEY PROFESSIONAL PAPER 239 PLATE 10

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SCAPHITES OF THE COLORADO GROUP

25
PLATE 11

[All figures natural size except as indicated on plate]

FIOURES 1-14. Scaphites impendicostatus Cobban, n. sp. 1-8, Side, front, rear, top, and bottom views, last suture, cross section of 

shell on straight part of living chamber, and cross section of shell at oral end of living chamber of holotype, an 

internal mold retaining part of the shell, U.S.N.M. 106686. From a bed of calcareous concretions in the Colorado 

shale 183-197 feet above top of calcareous member of Greenhorn age at map locality 47. 9, 10, Front and side 

views of an immature specimen with most of the shell, U.S.N.M. 106687, from the same locality. 11-13, Bottom, 

rear, and side views of a coarsely ribbed specimen, an internal mold with part of the shell, U.S.N.M. 106689. From 

the Colorado shale 500-580 feet below the top at map locality 20. 14, Cross section of septate whorls at diameter 

of 26 mm. of an incomplete specimen, U.S.N.M. 106688. From a limestone concretion at base of Niobrara shale 

. member of Cody shale at map locality 91 (p. 28). *

15-28. Scaphites impendicostatus var. erucoides Cobban, n. var. 15, 16, Side and rear views of an immature specimen, an 

internal mold with nearly complete living chamber, U.S.N.M. 106691, from same locality as figure 14. 17-22, 

Third from last suture, and bottom, top, front, rear, and side views of holotype, an internal mold, U.S.N.M. 106690. 

From a sandstone bed at top of Frontier formation at map locality 199. 23, 24, Side and bottom views of an 

internal mold with some of the shell, U.S.N.M. 106692a. From a bed of calcareous concretions 514-525 feet below 

top of Colorado shale at map locality 35. 25-28, Side, front, and bottom views, and next to last suture (composite) 

of a small adult specimen, U.S.N.M. 106692b, possessing fewer ribs than the typical form. From same locality as 

figures 23, 24 (p. 29).
(iEOLOOICAL SURVEY rROKKKKIONAI, PAPKR 239 PLATE 11

23 24 25 

SCAPIIITES OF THE COLORADO GROUP
PLATE 12

[All figures natural size except as indicated on plate]

FIGURES 1-10. Scaphites'ventricosus Meek and Hayden. 1-4, Bottom, top, rear, and side views of a specimen retaining part of the 

shell, U.S.N.M. 106700. From a sandstone bed 538 feet abpve..base of Cody shale at map locality 177. 5, 6, Rear 

and side views of an internal mold of an incomplete adult living chamber, U.'S.N.M. 106699, showing the right-angle 

bend between the aperture and the umbilical wall. From a ferruginous concretion bed 306-392 feet below top of 

Colorado shale at map locality 18. 7, Suture of a specimen; U.S.N.M. 106698, from same locality as figures 5, 6. 

8-10, Side, bottom, and top views of holotype, U.S.N.M. 1903. From Colorado shale at map locality 55 (p. 31).
GEOLOGICAL SURVEY PROFESSIONAL PAPER 239 PLATE 12

SCAPHITES OF THE COLORADO GROUP
PLATE 13

[All figures natural size except as indicated on plate]

FIGURES 1-10. Clioscaphites saxitonianus (McLearn). 1-5, Side and rear views and suture of the internal whorls of a specimen, 

U.S.N.M. 106739b. From a calcareous concretion in the Colorado shale 165 feet below the top at map locality 38. 

6-10, Side, top, rear, and bottom views, and last suture of an internal mold retaining a little of the shell, U.S.N.M. 

106739a, from the same locality (p. 36). ''" ' 

' 11-13. Scaphites ventricosus Meek and Hayden. Side, rear, and bottom views of a slightly crushed internal mold, U.S.N.M. 

106757. From a ferruginous concretion 330 feet below top of Colorado shale at map locality 39 (p. 31).
GEOLOGICAL SURVEY PROFESSIONAL PAPER 289 PLATE 13

11

SCAPHITES OF THE COLORADO GROUP
PLATE 14

[All figures natural size except as indicated on plate]

FIGURES 1-10. Scaphites tetonensis Cobban, n. sp. 1-5, Side, rear, top, and bottom views, and next to last suture of a partly crushed 

small paratype, U.S.N.M. 106708. From Cody shale 1,283 feet above base at map locality 179. 6-10, Side, 

rear, bottom, and top views, and last suture of holotype, an internal mold, U.S.N.M. 106707. From Cody shale 

500 feet above base at map locality 177 (p. 31).

11-16. Scaphites binneyi Reeside. 11-15, Last suture, and top, bottom, rear, and side views of a stout variant, an internal 

mold, U.S.N.M. 106705. From the Cody shale 574-774 feet above base at map locality 201. 16, Suture at diameter of 22 mm. of a specimen, U.S.N.M. 106706. From the Cody shale 450-574 feet above the base at map locality 

200 (p. 32).

17-21. Scaphites interjectus Reeside. Seventh from last-suture, and side, rear, top, and bottom views of a small specimen, 

U.S.N.M. 106701. From a calcareous concretion in the Cody shale about 1,500 feet above the base at map locality 

189 (p. 32).
GEOLOGICAL SURVEY PROFESSIONAL PAPER 239 PLATE 14

X3

19 20 

SCAPHITES OF THE COLORADO GROUP
PLATE 15

[All figures natural size except as indicated on plate]

FIGURES 1-5. Scaphites depressus Reeside yar. stantoni Reeside. Side, rear, top, and bottom views, and last suture of a specimen, 

U.S.N.M. 106695, transitional from S. ventricosus. From a ferruginous concretion 370 feet above base of Cody 

shale at map locality 148 (p. 33).

6-8. Scaphites depressus Reeside. Second from last suture, and side and rear views of a specimen retaining much of the 

shell, U.S.N.M. 106693. From a calcareous concretion about 700 feet above base of Cody shale at map locality 

145 (p. 32).
GEOLOGICAL SURVEY PROFESSIONAL PAPER 239 PLATE 15

irff-f _ j * ^. i sin rti Mr-^S;-:4$&.

SCAPHITES OF THE COLORADO GROUP
PLATE 16

[All figures natural size except as indicated on plate]

FIGURES 1-11. Clioscaphites montanensis Cobban, n. sp. , From a'bed of calcareous concretions 234-252 feet below top of Colorado 

shale at map locality 33. 1-5, Side, rear, top, and bottom views, and last suture of holotype, U.S.N.M. 106716. 

6-8, Side, front, and rear views of an internal mold of septate whorls at diameter of 13 mm. of a specimen, U.S.N.M. 

106717c. 9-11, Side, top, and bottom views of an internal mold retaining some of the shell, U.S.N.M. 106717b 

(p. 34).

12-14. Clioscaphites montanensis Cobban var. hesperius Cobban, n. var. Side, rear, and bottom views of holotype, U.S.N.M. 

106718, from the same locality (p. 34).
GEOLOGICAL SUKVEY PROFESSIONAL PAPER 239 PLATE 16

SCAPHITES OF THE COLORADO GROUP
PLATE 17

[All figures natural size except as indicated on plate]

FIGURES 1-3. Clioscaphites montanensis Cobban, n. sp. Side and bottom views, and suture at diameter of 56 mm. of a large internal 

mold, U.S.N.M. 106717d. From a bed of calcareous concretions 234-252 feet below top of Colorado shale at map 

locality 33 (p. 34).

4-7. Clioscaphites montanensis Cobban var. hesperius Cobban, n. var. Bottom, front,, and side views, and second from last 

suture of a large internal mold, U.S.N.M. 106719, from the same locality (p. 34).
GEOLOGICAL SURVEY PROFESSIONAL PAPER 239 PLATE 17

Xli

Xll

SCAPHITES OF THE COLORADO GROUP
PIATE 18

[All figures natural size except as indicated on plate]

FIGURES 1-6. Scaphites coloradensis Cobban, n. sp. From calcareous concretions 234-252 feet below top of Colorado shale at map 

locality 33. 1-4, Bottom, top, and side views, and next to last suture of holotype, an internal mold, U.S.N.M. 

106715. 5, 6, Fourth from last suture, and cross section through septate whorls and oral end of living chamber of 

an adult specimen, U.S.N.M. 106714 (p. 33).

7-27. Clioscaphites vermiformis (Meek and Hayden). From same locality as figures 1-6. 7-11, Side, rear, top, and bottom 

views, and last suture of a small specimen retaining the shell on the septate whorls and partly on the living chamber, 

U.S.N.M. 106713d. 12-15, Side, bottom, front, and rear views of the internal whorls at diameter of 18.5 mm. of a 

specimen retaining much of the shell, U.S.N.M. 1067l3e. 16-19, Side, front, and rear views, and last suture of an 

immature specimen, an internal mold with complete living chamber, U.S.N.M. 1067l3f. 20, 21, Side and bottom 

views of the internal mold of the older part of the living chamber of a sharp-ribbed variant, U.S.N.M, 106713b. 

22, 23, Bottom and side views of the smallest known adult specimen, U.S.N.M. 106713c. 24-27, Side, rear, bottom, 

and top views of a slightly larger than average adult specimen, U.S.N.M. 106713a (p. 35).
GEOLOGICAL SURVEY PROFESSIONAL PAPER 239 PLATE 18

24 25 26 

SCAPHITES OF THE COLORADO GROUP

27
PLATE 19

[All figures natural size except as indicated on plate]

FIGURES 1-10. Clioscaphites vermiformis (Meek and Hayden) var. toolensis Cobban, n. var. 1-5, Side, top, bottom, and rear views, 

and second suture (composite) from last of holotype, U.S.N.M. 106709. From a bed of calcareous concretions 

234-252 feet below top of Colorado shale at map locality 33. 6-8, Last suture, and side and top views of the 

septate coil and part of the living chamber of a densely ribbed specimen, U.S.N.M. 106712. From a calcareous 

concretion near middle of Cody shale at map locality 98. 9, Fragment of the living chamber of the largest known 

specimen, U.S.N.M. 106710, from same locality as figures 1-5. 10, Cross section of septate whorls of an adult, 

U.S.N.M. 106711. From a calcareous concretion in the Niobrara member of the Cody shale at map locality 96 

(p. 36).
GEOLOGICAL SURVEY PEOPE88IONAL PAPER 239 PLATE 19

SCAPHITES OF THE COLORADO GROUP
PLATE 20

[All figures natural size except as indicated on plate]

FIGURES 1-4. Clioscaphites montanensis Cobban, n. sp. From calcareous concretions 234-252 feet below top of Colorado shale at 

map locality 33. 1, Cross section of septate whorls of an internal mold at diameter of 38 mm., U.S.N.M. 106726b. 

2-4, Side and front views, and last suture of the internal mold of an immature specimen with complete living 

chamber, U.S.N.M. 106726a (p. 34).

5-7. Clioscaphites saxitonianus (McLearn) var. keytei Cobban, n. var. Side, top, and bottom views of holotype, an internal 

mold retaining part of the shell, U.S.N.M. 106727. From a calcareous concretion near top of Apishapa shale at 

map locality 266 (p. 37). 

8 11. Clioscaphitesl choteauensis Cobban, n. sp. Side, bottom, and rear views, and last suture of holotype, U.S.N.M.

106728. From a calcareous concretion near top of Colorado shale at map locality 44 (p. 38).

12-16. Clioscaphites platygastrus Cobban, n. sp. Last suture, and side, rear, top, and bottom views of holotype, an internal 

mold, U.S.N.M. 106729. From a calcareous concretion in upper part of Colorado shale at map locality 10 (p. 36).
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[All figures natural size except as indicated on plate]

FIGURES 1-9. Clioscaphites novimexicanus (Reeside). 1-3, Side and top views, and third from last suture of a nearly complete 

internal mold with some of the shell, U.S.N.M. 106722a. From near top of Colorado shale at map locality 14. 

4-6, Side, front, and rear views of the internal whorls of a specimen at diameter of 16.5 mm., U.S.N.M. 106721b. 

From a calcareous concretion 10 feet below top of Colorado shale at map locality 30. 7, Suture of an incomplete 

specimen, U.S.N.M. 106721a, from same locality as figures 4-6. 8, Side view of an artificial cast made from the 

impression of a specimen, U.S.N.M. 106722b, from same locality as figures 1-3. 9, Rear view of a fragment of a 

stout variant, an internal mold, U.S.N.M. 106723. From a concretionary bed 23 feet below top of Colorado 

shale at map locality 13 (p. 37).

10-23. Desmoscaphites erdmanni Cobban, n. sp. From same locality as figures 4-6. 10,11, Side and rear views of holotype, 

an internal mold of most of a living chamber, U.S.N.M. 106724. 12, 13, Side and front views of an incomplete 

specimen showing the coarse-ribbed outer septate whorl and beginning of the fine-ribbed living chamber, U.S.N.M. 

106725c. 14-18, Side and rear views, and last suture of an internal mold of a young specimen with part of the 

living chamber, U.S.N.M. 106725a. 19, Cross section of septate whorls at diameter of 9 mm. of an internal mold, 

U.S.N.M. 106725b. 20-23, Side and front views of a septate internal mold showing constrictions and beginning 

of ribbing, U.S.N.M.-106725d (p. 38).

24-26. Scaphites leei Reeside. From same locality as figures 4-6. 24, 25, Rear and side views of internal mold of a living 

chamber and part of septate whorl, U.S.N.M. 106720b. 26, Next to last suture of a plesiotype, U.S.N.M. 106720a 

(p. 34).
OiEOLOfilCAL SURVEY PROFESSIONAL PAPER 239 PLATE 21

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