Multinodose Scaphitid Cephalopods 

from the Lower Part of the Pierre 

Shale and Equivalent Rocks in the

GEOLOGICAL SURVEY PROFESSIONAL PAPER 483-E

Multinodose Scaphitid Cephalopods 

from the Lower Part of the Pierre 

Shale and Equivalent Rocks in the 

Conterminous United States

By WILLIAM A. COBBAN and GLENN R. SCOTT

CONTRIBUTIONS T O PALEONTOLOGY

GEOLOGICAL SURVEY PROFESSIONAL PAPER 483-E

Three species of ammonites, assigned to the new genus 

Trachyscaphites,^>r0^/dk a means for the correlation of Upper Cretaceous strata between the Western Interior, the Gulf Coastal Plain, and Europe

UNITED STATES GOVERNMENT PRINTING OFFICE, WASHINGTON : 1964
UNITED STATES DEPARTMENT OF THE INTERIOR 

STEWART L. UDALL, Secretary

GEOLOGICAL SURVEY 

Thomas B. Nolan, Director

The U.S. Geological Survey Library has cataloged this publication as follows:

Cobban, William Aubrey, 1916-

Multinodose scaphiticl cephalopods from the lower part of 

the Pierre Shale and equivalent rocks in the conterminous 

United States, by William A. Cobban and Glenn K. Scott, 

Washington, U.S. Govt. Print. Off., 1964.

iii, 13 p. 4 plates, map, diagrs., tables. 29 cm. (U.S. Geological 

Survey. Professional paper 483-E)

Contributions to paleontology.

Bibliography: p. 12-13.

1. Ammonoidea. 2. Scaphites. 3. Paleontology Cretaceous. I. 

Scott, Glenn Robert, 1918 joint author. II. Title. (Series)

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

Washington, B.C. 20402
CONTENTS

Abstract..___________________________

Introduction. ________________________

Geographic distribution._______________

Stratigraphic summary._______________

Important associated fossils ____________

Comparisons with other scaphitid faunas. 

Gulf Coastal Plain________________

Europe._________________________

Systematic descriptions. 

Ref erences cited _______

Page 

El

1

2

2

3

4

4

5

6

6

12

ILLUSTRATIONS

PLATE 1. Trachyscaphites redbirdensis Cobban and Scott.

2, 3. Trachyscaphites spiniger (Schliiter) subsp. porchi Adkins.

4. Trachyscaphites praespiniger Cobban and Scott.

FIGURE 1. Index map___-_-_-___-_-___-_-_-___-___-___-----_--

2. Correlation chart- __________________________________

3. Sutures of Trachyscaphites redbirdensis- _______________

4. Sutures of Trachyscaphites spiniger subsp. porchi--------

5. Sutures of Trachyscaphites praespiniger- _____-_-_-_-_--

Page

E3

4

8

11

12

III

CONTRIBUTIONS TO PALEONTOLOGY

MULTINODOSE SCAPHITID CEPHALOPODS FROM THE LOWER PART OF THE PIERRE 

SHALE AND EQUIVALENT ROCKS IN THE CONTERMINOUS UNITED STATES

By WILLIAM A. COBBAN and GLENN R. SCOTT

ABSTRACT

Scaphitid ammonites that have three to five rows of nodes 

on each flank of the living chamber are known from the Pierre 

Shale at 13 localities in Wyoming, South Dakota, Colorado, and 

Kansas, and from the equivalent rocks at seven localities in 

Montana, Wyoming, Utah, and Colorado. Elsewhere in the 

United States this group of scaphites is known only in Texas 

where it is represented by one species.

Three species are known from the United States, and all are 

assigned to a new genus Trachyscapliites. These species are, 

from oldest to youngest, T. praespiniger (n. sp.), T. spiniger 

(Schluter) subsp. porclii Adkins, and T. redbirdensis (n. sp. and 

the genotype). European species assigned to this genus are 

Scaphites spiniger Schluter, 8. pulcherrimus Roemer, and, 

questionably, S. gibbus Schluter.

Tracliyseaphites is of Campanian age. Schluter's Scapliites 

spiniger and his Ammonites [Hoplitoplacenticeras] coesfeldiemis, which is found with the scaphite, are well-accepted index 

fossils for the lower part of the upper Campanian in Europe. 

The American equivalent of Schluter's scaphite is interpreted 

as a geographic subspecies (porchi Adkins) ; it occurs with 

Hoplitoplacentieeras in the Wolfe City Sand Member and Pecan 

Gap Chalk Member of the Taylor Marl in Texas. Trachyscaphites spiniger (Schluter) subsp. porclii Adkins is assigned an 

early late Campanian age, and the slightly older T. praespiniger 

of the Western Interior is assigned a very late early Campanian 

age.

INTRODUCTION

Scaphites that have more than two rows of nodes on 

each flank have been collected from rocks of late early 

Campanian and early late Campanian age at 20 localities in the Western Interior. Their presence in this area, 

however, has been noted only once in the literature 

(Fisher and others, 1960, /Scaphites cf. S. pulcherrimus 

Roemer on p. 30, table 9). The Western Interior specimens are represented by two new species and a subspecies which, together with other multinodose species 

of similar age, can be grouped conveniently in a new 

genus Trachyscaphites. The American species are, 

from oldest to youngest, Trachyscaphites praespiniger, n. sp., T. spiniger (Schluter) subsp. porchi Adkins,

and T. redbirdensis, n. sp. The European species assigned to this genus are /Scaphites spiniger Schluter, 

8. pulcherrimus Roemer, and possibly 8. gibbus 

Schluter.

The occurrence of multinodose scaphites in the 

Western Interior is important in dating the rocks in 

which they occur inasmuch as closely related species are 

found in the Upper Cretaceous of Europe. Schluter's 

/Scaphites spiniger is an accepted guide fossil to rocks 

of early late Campanian age in Germany, France, 

Sweden, Poland, and Russia. Trachyscaphites spiniger 

(Schluter) subsp. porchi Adkins is interpreted as a 

geographic subspecies of the European species. 

Trachyscaphites praespiniger, n. sp., the earliest of the 

multinodose species in the Western Interior, seems to 

be near the age of Schluter's Scaphites gibbus, which 

lies in the lower part of the range zone of his 8. spiniger. 

Trachyscaphites redbirdensis, n. sp., has five rows of 

nodes on each flank, and may be of an age comparable 

to that of Roemer's Scaphites pulcherrimus, which also 

has five rows of nodes and occurs in rocks above those 

containing Schluter's 8. spiniger.

Trachyscaphites is rare in the Western Interior except in the vicinity of Pueblo, Colo., where specimens 

of T. praespiniger are common but unfortunately are 

badly crushed. A few uncrushed septate coils of this 

species have been collected in Wyoming and Utah, but 

only bits of living chambers have been found. Trachyscaphites spiniger subsp. porchi is known from only 

six localities, and all specimens are either crushed or 

very fragmentary. Trachyscaphites redbirdensis. on 

the other hand, is represented by few, but very well 

preserved, specimens from limestone concretions.

The figured specimens are in the U.S. National 

Museum iii Washington, D.C. Mr. James H. Smith, of 

the Mountain Fuel Supply Co. (Salt Lake City), kindly 

donated three collections of Trachyscaphites praespiniEl
E2 CONTRIBUTIONS TO PALEONTOLOGY

ger from the area south of Eawlins, Wyo., and obtained 

permission from his company for the authors' publication of these specimens and accompanying stratigraphic 

data. Mr. James P. Conlin, Fort Worth, Tex., loaned 

the authors several fine examples of Trachyscaphites 

spiniger subsp. porchi, one of which is figured (pi. 3, 

fig. 8). All photographs were made by Kobert E. Burkholder, of the U.S. Geological Survey.

GEOGRAPHIC DISTRIBUTION

Trachyscaphites is known from 20 localities in the 

Western Interior of the conterminous United States. 

The general position of each locality is shown by map 

numbers on figure 1, and the stratigraphic position is 

indicated by the numbers enclosed by circles on figure 

2. Details regarding the localities, stratigraphic assignment, and collectors are given in the table below.

TABLE 1. Localities at which fossils were collected

TABLE 1. Localities at which fossils were collected Continued

Locality

on figs.

1,2

12.

U.S. Geol.

Survey 

Mesozoic

locality

D3866-_.__

D3436-

D2377--..

D190C__

D2327-.--

D3046.--__

D3290- 

D3293___._

23261.

13714.

D1780-.

D843_

Collector and year of collection, description of locality, 

and stratigraphic assignment

J. B. Gill, 1962. Reed Hill, 1 mile east of Judith River, 

in SW^SE^NW^ sec. 14, T. 22 N., R. 16 E., Fergus 

County, Mont. Claggett Shale, 40 ft above S.S^ft bentonite bed and 121 ft above base of formation.

J. R. Gill and W. A. Cobban, 1960. About 7.5 miles east 

of Hardin, in NEJCNW^NEM sec. 13, T. 1 S., R. 34 E., 

Big Horn County, Mont. Cody Shale, from a gray limestone concretion overlying 18-in. bentonite bed at base of 

Claggett Shale Member.

J. R. Gill, 1959. Seven miles northwest of Newcastle, in 

SE^ sec. 5, T. 45 N., R. 62 W., Weston County, Wyo. 

Pierre Shale, 188 ft above base of Red Bird Silty Member.

W. J. Mapel and W. A. Cobban, 1958. About 2.2 miles 

northeast of Red Bird, in WHSW^NWJ^ sec. 13, T. 

38 N., R. 62 W., Niobrara County, Wyo. Pierre Shale, 

from limestone concretions 218 ft above base of Red Bird 

Silty Member.

W. A. Cobban, 1946. One mile west of Ardmore, in WM 

sec. 8, T. 12 S., R. 4 E., Fall River County, S. Dak. 

Pierre Shale, from limestone concretions in Gammon 

Ferruginous Member just beneath Ardmore Bentonite 

Bed of Spivey (1940).

J. H. Smith, 1961. Eighteen miles southeast of Rawlins, 

in SWJi sec. 35, T. 19 N., R. 86 W., Carbon County, 

Wyo. Steele Shale, 942 ft below top.

J. H. Smith, 1961. Eleven miles south of Rawlins, in 

SEK sec. 12, T. 19 N., R. 88 W., Carbon County, Wyo. 

Steele Shale, 405 ft below top.

J. H. Smith, 1961. Fourteen miles southeast of Rawlins, 

in SEJ4 sec. 24, T. 19 N., R. 87 W., Carbon County, 

Wyo. Steele Shale, 415 ft below top.

W. A. Cobban, 1945. Seven miles southeast of Jensen, in 

sec. 13, T. 6 S., R. 23 E., Uintah County, Utah. Mancos 

Shale, from a limestone concretion 344 ft below top.

J. B. Reeside, Jr., 1926. East Salt Creek, 9 miles southeast 

of Carbonera, in NE^ sec. 31, T. 7 S., R. 102 W., Garfleld 

County, Colo. Mancos Shale, 250 ft below top.

W. J. Hail, 1958. Seventeen miles northwest of Walden, 

in NEM sec. 36, T. 11 N., R. 82 W., Jackson County, 

Colo. Pierre Shale, from a limestone concretion about 

300 ft above base.

R. Van Horn, 1956. Northwest shore of Ralston Reservoir, 

5.3 miles north-northwest of Golden, in SEJ^NWi^SEJ^ 

sec. 32, T. 2 S., R. 70 W., Jefferson County, ColoPierre Shale, from ferruginous siltstone concretions 385 ft 

above base.

Locality

on figs.

1,2

13.

14-

15.

17-

19.

20.

U.S. Geol.

Survey 

Mesozoic

locality

D267.

D67-

D1229.--.

D3454. -

D2812...-

1367-

D3456 ..

D2591 -

Collector and year of collection, description of locality, 

and stratigraphic assignment

G. R. Scott, 1954. About 7.5 miles southwest of Littleton. 

in NW^SE^SWK sec. 15, T. 6 S., R. 69 W., Jefferson 

County, Colo. Pierre Shale, about 610 ft above base.

G. R. Scott, 1954. About 8 miles southwest of Littleton, in 

SE^SW^NEM sec. 22, T. 6 S., R. 69 W., Jefferson 

County, Colo. Pierre Shale, from a limestone concretion 

150 ft below base of Hygiene Sandstone Member and 

1,065 ft above base of formation.

G. R. Scott and W. A. Cobban, 1957. Steele Hollow, 1.6 

miles south of Pinon, in NE^NW^SE^ sec. 12, T. 19 

S., R. 65 W., Pueblo County, Colo. Pierre Shale, from 

limestone concretions at base of Sharon Springs Member 

and 428 ft above base of formation.

G. R. Scott, 1961. North of Gnat Hollow and about 7 miles 

north of Pueblo, in WJ^NWJi sec. 25, T. 19 S., R. 65 W., 

Pueblo County, Colo. Pierre Shale, from limestone 

concretions at base of Sharon Springs Member and 428 ft 

above base of formation.

G. R. Scott and W. A. Cobban, 1958. Gnat Hollow, 6 

miles north of Pueblo, in NE^NW^SE^ sec. 26, T. 19 

S., R. 65 W., Pueblo County, Colo. Pierre Shale, from 

limestone concretions at base of Sharon Springs Member 

and 428 ft above base of formation.

G. K. Gilbert and G. W. Stose, 1894. About 3.7 miles 

northeast of Pueblo, in SW^NE^SW^ sec. 8, T. 20 S., 

R. 64 W., Pueblo County, Colo. Pierre Shale [base o 

Sharon Springs Member].

G. R. Scott, 1961. About 2 miles southwest of Pinon, in 

NHSEKSEM sec. 11, T. 19 S., R. 65 W., Pueblo County, 

Colo. Pierre Shale, 10 ft above base of Sharon Springs 

Member and 438 ft above base of formation.

G. R. Scott and W. A. Cobban, 1956. One mile northeast 

of McAllaster, in NE^[ sec. 13, T. 12 S., R. 37 W., Logan 

County, Kans. Pierre Shale, from a limestone concretion 

40 ft below top of Sharon Springs Member.

STRATIGRAPHIC SUMMARY

Trachyscaphites has been found in the Claggett Shale 

of central Montana, the Claggett Shale Member of the 

Cody Shale of south-central Montana, the Gammon 

Ferruginous Member and Eed Bird Silty Member of 

the Pierre Shale of the Black Hills area of eastern 

Wyoming and southwestern South Dakota, the Steele 

Shale of south-central Wyoming, the Mancos Shale of 

northeastern Utah and northwestern Colorado, the 

lower part of the Pierre Shale of central Colorado, and 

the Sharon Springs Member of the Pierce Shale of 

south-central Colorado and western Kansas. The correlation of these formations and members is shown on 

figure 2. For the general relationships of these units 

to other formations in the Western Interior, the reader 

is referred to papers by Cobban and Eeeside (1952), 

Keeside (1957), and Weimer (1960); and for more 

detailed data concerning some of the correlations, see 

Scott and Cobban (1959, 1963), Zapp and Cobban 

(1960,1962), and Gill and Cobban (1961,1962).

The sequence of baculites shown on figure 2 serves 

as a useful time scale to which the species of 

Trachyscaphites can be referred. This succession of
MULTINODOSE SCAPHITID CEPHALOPODS E3

109° 107' 105 C 103 C 101'

JJTAH, I ~ Grand Junction

37°- --

0 50 100 150 200 MILES i i i i i i_____I_____i____ i

FIGURE 1. Index map showing localities of Trachyscaphites. Numbers refer to the detailed descriptions of localities in the table.

baculites is based largely on the large collections from 

the Pierre Shale on the west and south flanks of the 

Black Hills uplift in eastern Wyoming and southwestern South Dakota, from the lower part of the 

Pierre Shale of the Front Eange. area in central Colorado, and from the Cody Shale of the Salt Creek oil 

field in central Wyoming (for a summary of most of

this baculitid sequence, see Cobban, 1962a, p. 705, 706). 

It is possible to subdivide the zone of Baculites obtusus 

into a lower part in which most of the baculites are 

rather weakly sculptured and an upper part in which 

most of the specimens are more strongly ornamented. 

The zone of B. perplexus can be subdivided into three 

subzones of which the oldest and youngest are characterized by baculites having coarsely ribbed venters, 

whereas the middle subzone is featured by baculites 

having more finely ribbed venters (B. gilberti Cobban).

IMPORTANT ASSOCIATED FOSSILS

Trachyscaphites praespiniger is associated with (1) 

an early form of Baculites obtusm Meek that is more 

weakly ribbed than the later (or typical) form of the 

species and (2) a slightly older species of Baculites 

that has very weak flank ribbing. The collections from 

near Pueblo, Colo. (fig. 1, Iocs. 15-19), also contain a 

weakly sculptured species of Inoceramus that seems 

referable to 7. agdjakendensis Aliev, a species described 

from the lower Campanian of Russia. Three of the 

lots from the Pueblo area contain crushed fragments of 

the ammonite Delawarella danei Young (1963, p. 114, 

pis. 57, 62, 64-66; text figs. 24e. 33b) known elsewhere 

only from the lower part of the Ozan Formation of 

southwestern Arkansas (figured as Mortoniceras aff. M. 

delawarense by Dane, 1929, pi. 10) and from the Gober 

Tongue of Austin Chalk in northeast Texas.

Trachyscaphites spiniger subsp. porchi occurs with 

Baculites tncleami and the slightly younger B. 

asperiformis. In both zones the subspecies is associated 

with an undescribed scaphite that is ancestral to the late 

Campanian nodosus group of species. Of considerable 

interest also is the presence of Inoceramus azerbaidjanensis Aliev with Trachyscaphites spiniger subsp. 

porchi and Baculites mclearni at USGS Mesozoic loc. 

D843 near Golden, Colo. (fig. 1, loc. 12). This inoceramid has been recorded previously only from the lower 

Campanian of Russia (Aliev, 1954; Aliev and Khalilov, 

1958, p. 290; Dobrov and Pavlova, 1959, p. 148; Rengarten, 1959, p. 480). Associated with the multinodose 

scaphites from the Baculites asperiformis Range Zone 

near Denver, Colo., is an undescribed Pteria-like, pelecypod that has concentric folds and, on some individuals, 

radial folds.

Trachyscaphites redbirdensis is known from only 

three localities, two of which lie at the base of the 

Baculites gregoryensis Range Zone; the other lies somewhere in the upper part of the B. perplexus Range Zone. 

The collections from the B. gregoryensis Range Zone 

are associated with a fine-ribbed nodeless scaphite and 

with the same undescribed scaphite found with 

Trachyscaphites spiniger subsp. porchi.
E4 CONTRIBUTIONS TO PALEONTOLOGY

Stage

Campanian 

(part)

Upper

Lower

Baculite 

range 

zones

Baculites gregoryensis

Baculites perplexus

Baculites sp. 

(smooth)

Baculites asperiformis

Baculites mclearni

Baculites 

obtusus

Late 

form

Early 

form

Baculites sp. 

(weakly ribbed)

Baculites sp. 

(smooth)

Baculites aquilaensis

Western Interior 

scaphite 

ranges

Scaphites hippocrepis nodeless (n. sp.)scaphite 

aquisgranensis Scaphites noded scaphite (n.sp.)

Indoscaphites n. sp. 

Trachyscaphites spiniger 

Trachyscaphites praespiniger subsp. porchi redbirdensis

Central Montana

Judith River 

Formation 

(part)

Claggett Shale

Eagle Sandstone

South-central 

Montana

Parkman 

Sandstone 

(part)

Cody Shale (prt)

Claggett Shale 

Member

(2)

Gammon 

Ferruginous 

Member

Black Hills, Wyoming 

and South Dakota

(part) Pierre Shal

Red Bird 

Silty Member

Mitten Black 

Shale Member

Sharon Springs 

Member

Gammon 

Ferruginous 

Member

^> Groat 

^^^ Sandstone 

^| Bed

Rawlins area, 

south-central 

Wyoming

Mesaverde 

Formation 

(part)

Steele Shale 

(part)

i'7)

FIGURE 2. Correlation of part of the Campanian rocks in the Western 

graphic positions of Trachyscaphites. The circled numbers indicate 

ties shown on figure 1.

COMPARISONS WITH OTHER SCAPHITID FAUNAS 

GULF COASTAL PLAIN

The only multinodose scaphites recorded from rocks 

of late early Campanian or early late Campanian age 

from the Gulf Coastal area are two forms described by 

Adkins (1929, p. 205, 206) as the new species Scaphites 

aricki and S. porchi. Both came from the same locality near Austin, Tex., where they occur in a phosphatic bed about 150 feet above the base of the Taylor 

Marl. Studies of scaphites from this locality as well 

as from other outcrops of comparable age in Texas have 

convinced the authors that Adkins' two forms represent one variable species which is herein interpreted as 

a geographic subspecies of the European Trachyscaphites spiniger. Adkins' name porchi has page priority 

over aricki and, accordingly, the Gulf Coast scaphite 

is assigned as T. spiniger (Schluter) subsp. porchi 

Adkins.

Associated fossils from the type locality of T. spiniger

subsp. porchi include ammonites described by Adkins as 

the new species Baculites taylorensis, Parapachydiscus 

travisi, and Hamites ? taylorensis. Baculites taylorensis 

is most closely related to B. asperiformis Meek; both 

have widely spaced lateral nodes, but B. taylorensis is a 

stouter species that retains its nodes to greater diameters. 

Trachyscaphites spiniger subsp. porchi is present in 

USGS Mesozoic collections from the Anacacho Limestone in southwestern Texas. Near San Antonio a brittle chalky limestone, regarded "as an eastward-thinning 

wedge of the Anacacho limestone" by Stephenson (1937, 

p. 136), contains this scaphite associated with Baculites 

taylorensis. In northeastern Texas the scaphite occurs 

in the Wolfe City Sand Member and overlying Pecan 

Gap Chalk Member of the Taylor Marl. Associated 

fossils in a collection (USGS Mesozoic loc. 9710) at hand 

from the Wolfe City Sand Member include Inocemmus 

a-zer~baidjanensis, Baculites cf. B. mclearni, and fragments of Hoplitoplacenticeras. Associated fossils in 

three collections examined from the Pecan Gap Chalk
MULTINODOSE SCAPHITID CEPHALOPODS E5

Vernal area, 

northeastern 

Utah

Mesaverde

Group

(part)

7

Mancos Shale

(9)

Grand Junction 

area, 

western Colorado

Sego Sandstone 

(part)

(10)

Mancos Shale 

(part)

North Park, Colorado

fQ. 

0)

ro

o

Sandy member 

(part)

©

Shaly member

Niobrara Formation 

(part)

Golden-Littleton area, 

Colorado

G.

<u 

ro

.c

ai

Hygiene Sandstone 

Member 

(part)

V_-'

©

©

(Shale)

Niobrara Formation 

(part)

Pueblo area, Colorado

t 

ro

_4)

ro 

CO

o>

<O

b.

Rusty member 

(part)

Sharon Springs 

Member

05) (16) (Q) © (19)

Apache Creek 

Sandstone Member

Transition member

Niobrara Formation 

(part)

McAllaster area, 

Kansas

t?

ro

Q.

<u

ro

Sherre 

Q.

(20)

Sharon Springs 

Member 

(part)

 5

Niobrara Formation 

(part)

Stage

Upper

Lower

Campanian

(part)

Interior snowing baculitid zones, scaphitid ranges, and the stratithe stratigraphic positions of TrachyscapMtes and refer to localiMember include BacuUtes cf. B. mclearnl at two 

localities and B. taylorensis at one locality. Young 

(1963, p. 64) recorded Hoplito placenticeras sp. aff. 

Metaplacentlceras I bowersi Anderson from the base of 

the Pecan Gap. These occurrences of Hoplito placenticeras in the Wolfe City and Pecan Gap are of considerable interest inasmuch as the only specimen of this genus 

known to the authors from the Western Interior is a 

fragment that may be H. coesfeMiense (Schliiter) var. 

scMuteri Mikhailov from the Bacul'ttes asperiformis 

Range Zone in south-central Wyoming (Cobban, 1963). 

The presence of Trachyscaphltes spinlger subsp. 

porclii, BacuUtes cf. B. mclearni, and Inoceramus 

azerbaidjanensls, in the Wolfe City Sand Member permits its correlation with rocks in the Range Zone of 

BacuUtes m-clearm in the Western Interior. The Pecan 

Gap probably correlates with part of this Range Zone 

as well as with the Range Zone of BacuUtes asperiformis. Representatives of Trachyscaphltes older than 

T. splniger have not been found in the Gulf Coastal

Plain. A correlation between the Western Interior 

rocks containing T. praesp'mlger and the Ozan Formation of southwestern Arkansas and the Gober Tongue 

of Austin Chalk of northeast Texas is suggested by the 

occurrences of T)ela\varella danel Young.

EUROPE

Schliiter (1876, p. 252) indicated the occurrence of 

his Scaphltes spinlger, 8. gibbus, Ammonites [HopUtoplacentlceras~\ coesfeldlensls, and A. [Hoplitoplacenticeras] vari, in his zone of Ammonites coesfeldlensis. 

Two of his species, S. splniger and A. van, were shown 

as ranging on up into his next higher zone of Heteroceras 

[Bostrychoceras] polyplocum, to which zone Schluter 

assigned Roemer's Scaphltes pulcherrimus. Most subsequent workers (for example, Grossouvre, 1893, p. 255; 

Nowak, 1916, p. 67; Pozaryski, 1938, p. 18; Mikhailov, 

1951, p. 109) have shown that Scaphltes gibbus occurs 

only in the lower part of the Range Zone of S. splniger,
E6 CONTRIBUTIONS TO PALEONTOLOGY

and some authors (for example, Grossouvre, 1893, p. 

255; Milhailov, 1951, p. 108; Naidiii and Shimanskii, 

1959, p. 214; Moskvin and Naidin, 1959, p. 506) have 

indicated Hoplitoplacenticeras is the same age as S. 

gibhus. Scapliites spiniger has been shown as ranging up through the level of S. pulcherrimus by most 

European authors, but Pozaryski (1938, p. 19; 1948, 

p. 116) showed /S. spiniger as an older species.

Thus, it is apparent that clearly defined zones in 

Europe based on species of Trachyscaphites cannot be 

determined from a survey of the literature. Some sort 

of zoning seems probable, judging from the restriction 

of Trachyscaphites I gibbus to the lower part of the 

Eaiige Zone of T. spiniger and the possibility that I'. 

pulcheni/tnm-s could be younger than T. spiniger.

A correlation of the Range Zone of Trachyscaphites 

spiniger in the United States with the lower part of the 

reported range of this species in Europe seems unquestioned. The European equivalents of T. jrntespiniger 

and T. redbirdensis are not so apparent. Trachyscaphites redbirdensis and T. pulcherrimus are probably of 

comparable age. Both have five rows of nodes on the 

flanks, and both occupy positions well above the lowest 

occurrence of T. spiniger. Trachyscaphites praespiniger, 011 the other hand, is more difficult to correlate 

inasmuch as 110 trachyscaphitid has been recorded from 

Europe below rocks containing T. spiniger. Grossouvre 

(1901, p. 801) proposed for the Campanian four zones 

of which the youngest (Zone a Pachydiscus neubergicus] is now assigned to the Maestrichtiaii. Of the 

other zones, Placenticeras [Diplacmoceras^\ bidorsatum, 

characterized the oldest, Mortoniceras [Delawaretta] 

delawarense marked the middle, and Hoplites \Hoplltoplacenticeras'] van, defined the youngest. The zone of 

Placenticera-s hidorsatum was said to contain Scaphites 

hippocrepis and S. aquisgranensis. species found below 

the level of Trachyscaphites in the United States (fig. 

2). Scapliites were not recorded from the zone of Mortoniceras delawarense, but inasmuch as the overlying 

zone contained T. spiniger and T. ? gibbus some sort of 

correlation of the Mortoniceras delawarense zone with 

the Range Zone of T. praespiniger seems possible. This 

correlation is further strengthened by the occurrence of 

Delawarella danei associated with T. pra-espiniger near 

Pueblo, Colo. Delawarella danei is in the Range Zone 

of Delaivarella delawarensis, according to Young (1963, 

p. 115).

AGE

Grossouvre's (1901, p. 830) division of the Campanian 

into a lower and upper part has been followed by most 

workers. His recognition of Hoplitoplacenticeras, 

Trachyscaphites spiniger, and T.? gibbus as guide 

fossils to the upper Campanian has been verified by

many investigators (for example, Pozaryski, 1938, p. 18; 

Jeletzky, 1951, p. 18; Riedel, 1951, p. 392; Naidin and 

Shimanskii, 1959, p. 214, 215), and Seitz (1953, p. 149) 

defined the base of the upper Campanian in Germany 

on the appearance of these species. Grossouvre's 

scheme of subdividing the lower Campanian into a lower 

zone characterized by Placenticeras [Diplacmoceras] 

hidorsatum and an upper zone marked by Mortoniceras 

[Delawarella] delawarense was followed by Muller and 

Schenck (1943, text fig. 6) in their recommendations 

for the zones of the standard Cretaceous. Among the 

fossils listed by Grossouvre (1901, p. 830) in his 

Placenticeras \Diplacmoceras\ hidorsatum zone were 

Scaphites hippocrepis, S. aquisgranensis, S. hinodosus, 

Pachydiscus dulmensis, and Actinocamax \G-onioteutlii*} granulatux. His Mortoniceras [Delawarella] 

delawarense zone was said to contain Actinocamax 

[Gonioteuthis~] quadratus and a few other fossils. 

Schliiter (1876, p. 252, 254) had earlier indicated that 

Scaphites hippocrepis (as S. cuvieri Morton) and 

Gonioteuthis quadrata. (as Actinocamax quadratus] occurred in the upper zone in Germany. Jeletzky (1955, 

p. 480) also showed the occurrence of these fossils in 

the same zone and, in addition, he assigned Scaphites 

aquisgranensis, S. binodosus, and Pachydiscus dulmemis 

to this zone. This shift of S. hippocrepis and S. 

aquisgranensis from the lower part of the lower Campanian to the upper part was revealed also in a recent 

French paper (Basse and Sornay, 1959, p. 21).

If Scaphites hippocrepis and S. aquisgranensis are 

accepted as marking the upper zone of the lower Campanian and Trachyscaphites spiniger and Hoplitoplacenticeras as marking the lower part of the upper 

Campanian, the problem arises as to what zone the 

American T. praespiniger should be assigned. Trachyscaphites praespiniger is certainly much more closely 

related to T. spiniger than to Scaphites hippocrepis or 

S. aquisgranensis, and this favors a late Campanian 

assignment. Yet the association of Delawarella danei 

and Inoceramus agdjaJ&endensis with T. praespiniger 

favors an assignment to the upper part of the lower 

Campanian. An assignment to the uppermost part of 

the lower Campanian seems to be the best choice in 

light of the associated fossils and the occurrence of T. 

praespiniger in rocks older than Hoplitoplacenticeras.

SYSTEMATIC DESCRIPTIONS

Genus TEACHYSCAPHITES Cobban and Scott, n. gen.

Trachyscaphites, with T. redbirdensis, n. sp., as genotype, is proposed for moderately large, typically robust 

scaphites that have the younger and greater part of the 

living chamber separated from the septate coil by a 

considerable gap. Ornamentation consists of three to
MULTINODOSE SCAPHITID CEPHALOPODS E7

five rows of nodes on each flank and dense ribbing, 

which on the living chamber tends to be weak and not 

differentiated into strong primaries and weaker secondaries as in most scaphite groups. The suture is 

moderately complex and has a broad bifid first lateral 

lobe and a much smaller trifid second lateral lobe.

The assignment of the European Scapliites spiniger, 

S. gibbus, and $. pulcherrimus has been a problem to 

many workers. Nowak (1912) proposed the genus 

AcantlioscapMtes for large scaphites that have whorls 

higher than wide, straight ribs with nodose thickening 

near the umbilicus, and, in the adults, one to three 

rows of nodes on each flank and ordinarily a midventral 

row. Nowak designated as the genotype /Scaphites 

tridens Kner (1850, p. 10, pi. 2, figs, la, Ib), a large 

form having on the living chamber a row of midventral 

nodes flanked by a row of ventrolateral nodes. As 

variants of Acanthoscaphites tridens, Nowak assigned 

Scaphites trinodosus Kner (1850, p. 11, pi. 2, figs. 2a-c) 

that has midventral, ventrolateral, and lateral nodes; 

S. varians Lopuski (1911, p. 120, pi. 4, figs. 1-3; text 

fig. 4) with umbilical nodes in addition to those on S. 

trinodosus; S. quadrispinosus Geinitz (1850, p. 116, pi. 

7, fig. 2; pi. 8, fig. 2) with ventrolateral and lateral 

nodes; and S. trispinosus Geinitz (1850, p. 116, pi. 7, 

figs, la, Ib) with midventral and ventrolateral nodes. 

In addition, Nowak proposed another variety, bispinosm, that has only ventrolateral nodes. To his new 

genus Acanthoscaphites, Nowak assigned with a query 

Schliiter's /S. gibbus which has umbilical, ventrolateral, 

and two rows of lateral nodes. No mention was made 

of the multinodose /S. spiniger Schluter or of S. pulcherrimus Roemer, but in a later paper Nowak (1916, p. 

63) assigned these to his Acanthoscaphites. This assignment of /S. spiniger and /S. pulcherrimus has been 

accepted by most workers (for example, Reeside, 1927, 

p. 27; Adkins, 1929, p. 205; Wolansky, 1932, p. 9; 

Pozaryski, 1938, p. 18; 1948, p. 70; Mikhailov, 1951, 

p. 96, 100; Naidin and Shimanskii, 1959, p. 195). Although Nowak (1912, p. 565) at first considered S. 

gibbus Schliiter as a possible member of Acanthoscaphites, he later assigned it to his genus Hoploscaphites. 

Reeside (1927, p. 27), however, considered 8. gibbus as 

belonging to Meek's subgenus Dlscoscaphites. an assignment followed by most recent Russian authors (for example, Mikhailov, 1951, p. 94; Naidin and Shimanskii, 

1959, p. 197; Moskvin and Naidin, 1959, p. 506; Pasternak, 1959, p. 85).

Trachyscaphites differs from Acanthoscaphites by its 

smaller size, whorls wider than high, simpler suture, 

lack of midventral nodes, and straighter living chamber 

which has the younger part separated considerably 

from the chambered whorls. The authors believe

Nowak made his genus Acanthoscaphites too inclusive, 

and that it should be restricted to a group of large 

tightly coiled scaphites in which midventral nodes are 

ordinarily present. In addition, the suture is highly incised for a scaphite, the ribs are straight, and the nodes 

are usually present only on the living chamber. In its 

very large size, tight degree of coiling, and complex suture pattern, Acanthoscaphites seems to be a parallel development of the American Rhaeboceras Meek (1876, p. 

462). These genera differ by the presence of midventral nodes on Acanthoscaphites and by the development of nodelike primary ribs on the living chamber of 

Rhaeboceras. Both forms occupy high positions in the 

Late Cretaceous close to the boundary of the Campanian 

and Maestrichtian. In the United States, Rhaeboceras 

is known only from the very late Campanian Range 

Zones of Baculites reesidei Elias and B. jenseni Cobban 

(for the treatment of these baculites, see Cobban, 

1962b). On the other hand, the forms of Acanthoscaphites that possess midventral nodes seem to be restricted to the Maestrichtian where they are almost 

confined to the lower half (Pozaryski, 1938, p. 18: 

Jeletzky, 1951, p. 18; Mikhailov, 1951, p, 109; 0dum, 

1953, p. 29; Schmid, 1955, p 83; Naidin and Shimanskii, 

1959, p. 215; Pasternak, 1959, p. 84).

Trachyscaphites differs from Discoscaphltes Meek 

(1876, p. 415, genotype, Ammonites conradi Morton) 

and Hoploscaphites Nowak (1912, p. 565, genotype, 

/Scaphites constrictus Sowerby) by its more robust shell, 

living chamber more extended away from the septate 

coil, and different node arrangement. The genotypes 

of Discoscaphites and Hoploscaphites are Maestrichtian 

species' that have tightly coiled compressed shells. 

Discoscaphites has four to nine rows of nodes on each 

side, whereas Hoploscaphites has one or twT o rows or 

more rarely none. Hoploscaphites has been applied to 

several species older than the genotype, such as the 

forms commonly assigned to the European Scaphites 

roemeri d'Orbigny and the American Scaphites nodosus 

Owen. These older species approach Trachyscaphites 

by having comparable extended living chambers and, 

for some individuals, robust shells, but none has the 

lateral row of nodes, and all have clearly defined primary ribs on the living chambers.

Trachyscaphites redbirdensis Cobban and Scott, n. sp. 

Plate 1, figures 1-7 ; text figure 3

This species is known from only six specimens, of 

which two are complete adults, two are septate coils, 

and two are fragments of living chambers. The species 

is characterized by four or five rows of nodes on each 

flank. On the living chamber each row of nodes is
E8 CONTRIBUTIONS TO PALEONTOLOGY

either considerably larger or smaller than the adjacent 

rows.

The early whorls were not studied in detail owing to 

their coarsely crystalline calcite filling which tended 

to shatter during preparation of the specimens. All 

whorls down to the smallest diameter observed, 3.5 mm, 

are wider than high. The rise of ornamentation could 

not be determined on the earliest whorls, but at a diameter of 3.5 mm ventrolateral swellings are discernible. 

The outer septate whorl is ornamented by strong 

rectiradiate ribs and sharp nodes. On the last half 

whorl about 10 primary ribs extend from small umbilical nodes out to the lower part of the flank where they 

terminate in a row of larger umbilicolateral nodes. 

Two secondary ribs extend from most of the nodes to 

the middle of the flank where they terminate in a row 

of lateral nodes. From these nodes secondaries and 

intercalates cross the remainder of the flank and venter. 

These ribs may be neatly arranged in pairs of which 

each pair is separated from adjacent pairs by a narrow 

furrow (pi. 1, fig. 1). Sharp ventrolateral and ventral 

nodes are present in the raised area between the furrows. The nodes in all but the umbilical row on each 

flank of the septate whorls tend to be of equal size.

Eibbing on the living chamber is not so distinct or so 

regular as that on the septate coil. Eibs crossing the 

venter number from 50 to 57. The nodes, likewise, are 

not regular in size, but instead they are differentiated 

into rows of strong nodes alternating with rows of weak 

ones. On each flank of the holotype five rows of nodes 

are present, and all extend to the aperture where they 

again become nearly equal in size. The rows are almost 

equally spaced and can be conveniently described as 

umbilical, umbilicolateral, lateral, ventrolateral, and 

ventral. The umbilical nodes are small and bullate and 

number 10 or 11 on the living chamber. The umbilicolateral nodes are much larger, number 13 or 14, and are 

rounded on the earlier part of the living chamber and 

bullate on the later part. The lateral nodes are small, 

rounded, and number 22. The ventrolateral nodes are 

the largest; they number 18 and are rounded to slightly 

clavate on the earlier part of the living chamber and 

rounded to bullate on the later part. The ventral nodes 

are small, rounded to bullate, and number 19 or 20. The 

distance across the venter between the two rows of 

ventral nodes is slightly more than that separating the 

ventral and ventrolateral rows of nodes.

The holotype (pi. 1, figs. 3-5, 7) is an internal mold 

113 mm high, 103 mm wide, and 63 mm thick. The 

aperture is slightly constricted and has a dorsal lappet.

The other complete adult (unfigured paratype USNM 

132312), from the same locality as the holotype, is 71 mm 

high and has poorly defined umbilical nodes. The

ventrolateral nodes are more clavate than those on the 

holotype.

The sutures of the holotype and a paratype of 

Trachyscaphites redbirdensis are shown on text figure 3. 

The first lateral saddle is as broad or broader than the 

ventral lobe. It is divided asymmetrically by a lobe 

which, on the holotype, is unusually large. The first 

lateral lobe is bifid, about as wide as the ventral lobe, 

and has a very broad base. The second lateral saddle is 

narrow and very asymmetrically bifid in which the 

ventrad part is the smaller. The second lateral lobe 

is much smaller than the first lateral lobe and is asymmetrically trifid.

Trachyscaphites redbirdensis resembles T. spiniger 

(Schliiter, 1872, p. 82, pi. 25, figs. 1-7) by the numerous 

rows of nodes on the living chamber and septate coil, 

but on the German species the nodes are more uniform 

in size and the umbilical row is missing. Trachyscaphites pulcherrimus (Eoemer, 1841, p. 91, pi. 14, fig. 4) 

resembles T. redbirdensis by possessing five rows of 

nodes, some of which disappear on the living chamber; 

those rows that do persist do not alternate in size. 

Trachyscaphites pulcherrinvuus is also a more slender 

species that has a more involute septate coil and a less 

extended living chamber. The specimen figured by 

Mikhailov (1951, p. 96, pi. 18, figs. 83, 84) more closely 

resembles T. redbirdensis than any figured by Schliiter

FIGURE 3. Sutures of Trachyscaphites redMrdensis Cobban and 

Scott, n. sp., X2. A, Paratype USNM 132310 at diameter of about 

35 mm (pi. 1, fig. 1). B, Holotype USNM 132300 at diameter of 

47 mm (pi. 1, figs. 3-5, 7).
MULTINODOSE SCAPHITTD CEPHALOPODS E9

(1872, p. 85, pi. 26, figs. 1-5), or Grossouvre (1893, p. 

250, pi. 32, figs. 6, 9a, 9b).

Types: Holotype USNM 132309; paratypes USNM 132310- 

132313. 

Occurrences: Wyoming, Iocs. 3,4; Colorado, loc. 14.

Trachyscaphites spiniger (Schliiter)

1872. Scaphites spiniger Schliiter, Palaeontographica, v. 21, p. 82,

pi. 25, figs. 1-7. 

1885. Scaphites spiniger Schliiter. Moberg Sveriges geol. undersokning, ser. C, no. 73, pt. 2, p. 28, pi. 3, figs. 6-8. 

1889. Scaphites spiniger Schliiter. Griepenkerl, Palaeont, Abh.,

v. 4, pt. 5, p. 405. 

1893. Scaphites spiniger Schliiter. Grossouvre, Les ammonites

de la craie superieure, p. 252. 

1902. Scaphites spiniger Schliiter. Wollemann, Kgl. preussische

geol. Landesanst, new ser., no. 37, p. 107.

1915. Scaphites spiniger Schliiter. Frech, Centralbl. Mineralogie 

Jahrg. 1915, .no. 21, p. 564, text fig. 13.

1916. Acanthoscaphites spinger (Schliiter). Nowak, K.-k. Geol.

Reichsanst. Verh., 1916, no. 3, fig. opposite p. 66. 

1925. Scaphites (Acanthoscaphites) spiniger Schliiter. Diener,

Fossilium Catalogus, I, Animalia, pt. 29, p. 207. 

1927. Acanthoscaphites spiniger (Schliiter). Reeside, U.S. Geol.

Survey Prof. Paper 150-B, p. 34.

1951. Acanthoscaphites spiniger (Schliiter). Mikhailov, Akad. 

Nauk SSSR, Inst. geol. >nauk Trudy, no. 129, Geol. ser. no. 50, 

p. 100, pi. 19, fig. 92.

1952. Scaphites spiniger Schliiter. Basse, in Piveteau, Jean, ed.,

Traite paleontologie, v. 2, p. 612. 

1954. Scaphites (Acanthoscaphites) spiniger Schliiter. Hagg,

Sveriges geol. undersokning, ser. C, v. 47, no. 6, p. 58.

Schliiter illustrated three examples from Haldem and 

Darup, Germany, of which one (Schliiter, 1872, pi. 25, 

fig. 4) is in the Geologisch-palaeontologisches Institut 

und Museum, Bonn, Germany." The others may have 

been lost during World War II (Dr. Hans Mensink, 

written communication, Apr. 25, 1958). None of the 

specimens was complete. The largest example figured 

(Schliiter, 1872, pi. 25, figs. 1-3) is composite and consists of the septate whorls and about two-thirds of the 

living chamber of a robust individual to which Schliiter 

added the oral part of another individual. The composite nature of this example is scarcely apparent in 

Schluter's drawing, although he drew attention to it 

and also pointed out that "Die laterale Knotenreihe 

liegt in Folge Verdriickung des Gehauses zu tief." 

Schluter's beautiful illustration has been copied much 

and reproduced in many textbooks (for example, Zittel, 

1900, fig. 1189; Abel, 1924, fig. 297; Chavan andMontocchio, 1956, cover; Davitashvili, 1958, fig. 257; Miiller, 

1960, fig. 271; Termier and Termier, 1960, fig. 2333). 

A second specimen figured by Schliiter (1872, pi. 25, 

figs. 5, 6) consists of about two-thirds of the younger 

end of a living chamber in which lies an aptychus. It is 

the most densely ribbed of his figured specimens, and 

his drawing suggests that the complete living chamber

717-109 O 64 2

probably had about 100 ribs crossing the venter. 

Schluter's third and extant specimen is badly crushed 

and lacks the oral end of the living chamber. It is the 

smallest and the most slender of the three examples. 

A plaster cast of this specimen is at the Federal Center. 

Denver, Colo.

Moberg (1885, pi. 3, figs. 6a, 6b) figured a complete 

adult from the Campanian of Sweden. It is a stout 

individual that shows a conspicuous change from 

rather coarse ribbing on the septate coil to fine weak 

ribbing on the living chamber. Kibs crossing the venter of the living chamber number about 100.

Frech (1915, fig. 13 on p. 565) illustrated a well-preserved living chamber from Haldem, Germany. This 

individual, which is as slender as the extant specimen 

of Schliiter, has about 100 ribs crossing the venter.

Mikhailov (1951, pi. 19, fig. 92) figured a septate coil 

and the beginning of the living chamber of a moderately 

large individual from Russia. It reveals irregularities 

in the strength of the ribs.

From the works of Schliiter, Moberg, Frech, and 

Mikhailov, the authors believe Trachyscaphites spiniger 

can be characterized as a moderately large species that 

ranges from a stout involute form to a smaller, slenderer, and less involute form. The living chamber is 

long, and more than half of it is completely freed from 

the septate coil. Sculpture consists of dense ribbing 

and four rows of nodes on each side. The ribs are 

slightly flexuous to nearly straight, and as many as 100 

cross the venter of the living chamber. On the last 

septate whorl ribbing is irregular and interrupted by 

node development. Some ribs tend to be grouped on 

high areas separated by furrows. These can be seen 

on Mikhailov's illustration (1951, pi. 19, fig. 92) as 

well as on a specimen at hand from Haldem. On the 

living chamber ribbing is uniform, dense, and, judging 

from Frech's and Moberg's illustrations, very weak. 

The ribs completely cover the flanks, but there seems to 

be no differentiation into strong primaries and weaker 

secondaries as in most other genera of scaphites.

The four rows of nodes are independent of the ribs 

according to Mikhailov (1951, p. 100) who referred to 

them as pupkovyi [umbilical], bokovoi [lateral], 

vneshne-bokovoi [outer-lateral], and vneshnii [outer]. 

In terms of the node arrangement on Trachyscaphites 

redbirdensis, T. spiniger lacks the umbilical row and 

has only the umbilicolateral, lateral, ventrolateral, and 

ventral rows. The umbilicolateral nodes are located 

some distance from the umbilical wall although not so 

far as indicated on the Darup specimen of Schliiter 

(1872, pi. 25, fig. 1). These nodes are rounded and 

number about 6 to 8 on the living chamber. The lateral 

nodes are also rounded to slightly clavate, but they
E10 CONTRIBUTIONS TO PALEONTOLOGY

tend to be smaller, judging from Frech's and Moberg's 

figures and from Griepenkerl's description (1889, p. 

405). They number about 12 to 16 on the living chamber. The ventrolateral nodes are rounded on the septate 

coil; but they become clavate on the living chamber, 

where they number about 14 to 18 and tend to be larger 

than the lateral nodes. The ventral nodes, likewise, are 

rounded on the septate coil and clavate on the living 

chamber, where they number about 15 to 20. They are 

comparable in size to the ventrolateral nodes. The ventral, ventrolateral, and lateral rows of nodes are about 

equally spaced, but the umbilicolateral row is a little 

farther removed. Each row persists to, or almost to, 

the aperture. Judging from Moberg's complete specimen, the distance across the venter separating the two 

rows of ventral nodes is about the same as the distance 

between the ventral and ventrolateral rows, although 

Schliiter's drawings show a much wider area between 

the rows of ventral nodes.

The authors are not aware of a published illustration of the suture. Grossouvre (1908, text fig. 13) figured the suture for a juvenile scaphite which he referred to as Scaphites cf. spiniger. His specimen came 

from the Chalk of Spiennes in Belgium, which apparently is of early Maestrichtian age and younger than 

Tracliy scaphites spiniger (Jeletzky, 1951, p. 19).

Trachyscaphites spiniger (Schliiter) subsp. porchi Adkins 

Plate 2, figures 1-23; plate 3, figures 1-11; text figure 4

1929. Scaphites porchi Adkins, Texas Univ. Bull. 2901, p. 205,

pi. 5, figs. 1-3. 

1929. Scaphites aricki Adkins, Texas Univ. Bull, 2901, p. 206,

pi. 5, figs. 7, 8. 

1963. Acanthoscaphites sp. cfr. A. spiniyer (Schliiter). Young,

Texas Univ. Pub. 6304, p. 49, pi. 4, figs. 1, 6, 7; pi. 5, figs.

1, 4, 5.

Adkins' /Scaphites porchi was based on fragments of 

four living chambers preserved as phosphatic internal 

molds. The holotype consists of the older three-fourths 

of an adult living chamber that belonged to an individual whose height was possibly 50 mm (about the 

size of plesiotype USNM 132319, pi. 2, figs. 8-10). The 

holotype is robust and has a depressed cross section. 

Ornamentation consists of four rows of strong nodes on 

each flank; the umbilicolateral, ventrolateral, and ventral nodes are of about equal size, and the lateral nodes 

are slightly smaller. All rows are nearly equally spaced 

including the distance across the venter between the two 

rows of ventral nodes. The umbilicolateral and lateral 

nodes are rounded, whereas the ventrolateral and ventral nodes are clavate. Ribs are not visible on this internal mold.

Adkins' Scaphites aricki was based on phosphatic internal molds of a septate coil with the beginning of the

living chamber (holotype), and the larger part of a 

living chamber (paratype) from the same locality asthe holotype of his S. porchi. The holotype is from a 

stout individual that was about the size of plesiotype 

USNM 132321 (pi. 3, figs. 10, 11). It is mostly the 

chambered part and is ornamented by four rows of 

nodes on each flank and by numerous thin but conspicuous ribs. The ribs, which are straight, can be divided 

into primaries and secondaries. Each primary bears 

an umbilicolateral node and terminates in the lateral 

node; at this point the rib branches into two or three 

secondaries which, together with intercalated ribs, cross 

the remainder of the flank and venter. On the earlier 

part of this septate coil, the area between the primary 

ribs tends to extend on across the venter as a narrow 

furrow separating higher areas on which two or three 

secondaries are located as well as the ventrolateral and 

ventral nodes. This character can be seen on many 

specimens from Texas and the Western Interior (for 

example, pi. 2, figs. 15, 16, 19, 20, 23) as well as on the 

earlier part of a septate coil of a specimen of T. spiniger 

at hand from Haldem, Germany. The septate coil of 

T. spiniger figured in a lateral view by Mikhailov (1951, 

pi. 19, fig. 92) would probably show this feature if 

viewed ventrally. The nodes on Adkins' holotype are 

of similar size and are rounded; each row is about 

equally spaced including the distance between the two 

ventral rows. Adkins did not illustrate his paratype, 

an incomplete living chamber, the ornament of which is 

described as "Ribbing and tuberculation on the straight 

limb are similar [to the septate holoytpe] but more 

open."

After studying collections referable to Adkins' 

Scaphites porchi and S. aricki from several localities in 

Texas including the type locality of these scaphites, the 

authors believe that these forms represent a single species that ranges from a large stout variant (aricki} to 

a smaller and more slender form (porchi} . This represents normal variation for scaphites (Cobban, 1951, p. 

4). The smallest adult figured (pi. 2, figs. 6, 7) is about 

31^ times as small as the largest (pi. 3, fig. 9).

The septate coils of specimens whose living chambers 

resemble the holotype of Adkins' Scaphites porchi are 

more slender than the holotype of his S. aricki but 

otherwise do not differ, and many are transitional from 

slender to stout. The sculpture of the living chamber 

shows the greatest amount of variation, ranging from 

strongly noded internal molds without ribs to more 

weakly noded internal molds with weak but dense ribbing. Where present, the ribs reveal no differentiation 

into stronger primaries and weaker secondaries. The 

four rows of nodes resemble those of the European examples of Trachyscaphites spiniger. The umbilico-
MULTINODOSE SCAPHITID CEPHALOPODS Ell

lateral nodes are rounded and situated away from the 

umbilical wall. The lateral nodes are rounded to 

clavate and may be as large as the umbilicolateral nodes 

or very much smaller (compare pi. 2, fig. 8 with pi. 3, 

fig. 1). The ventrolateral and ventral nodes are 

clavate and about the size of the umbilicolateral nodes. 

The lateral, ventrolateral, and ventral rows of nodes 

are about equally spaced, and the distance across the 

venter between the two ventral rows is comparable. 

Each row of nodes extends to the aperture. The number of nodes on the living chambers of the specimens 

examined is summarized as follows, together with a 

summary of the nodes on T. spiniger porchi as figured 

by Schluter, Moberg, and Frech:

Fossil Umbilicolateral

6-8

4-6

Lateral

13-16 7-13

Ventrolateral

14-18

10-12

Ventral

15-20

10-13

The moderately complex suture is characterized by 

the very broad-based bifid first lateral lobe and the much 

smaller trifid second lateral lobe. The first lateral saddle is asymmetrically bifid and as large as the ventral 

lobe. Sutures of two specimens from Texas are shown 

on figure 4.

The American specimens differ from the European 

species by possessing fewer nodes on the living chamber 

and by a tendency toward stronger tuberculation accompanied by loss of ribbing on internal molds. These 

differences seem sufficient to regard the American form 

as a geographic subspecies.

Types: Plesiotypes USNM 132314-132332. 

Occurrences: Montana, loc. 1; Colorado, Iocs. 10-13; Kansas, 

loc. 20.

Trachyscaphites praespiniger Cobban and Scott, n. sp. 

Plate 4, figures 1-13; text figure 5

This species is characterized by three or, rarely, 

four rows of flank nodes of which generally only 

one row (lateral) persists entirely around the last septate whorl. Ribbing is strong on the septate coil and 

weak on the living chamber.

The septate whorls are stout and wider than high in 

the smallest cross section observed (6 mm). Ribs are 

well developed at a diameter of 16 mm, but the diameter 

at which they first appear was not determined. The last 

half whorl has about 10 or 11 primary ribs which begin 

at the umbilicus and curve slightly forward on crossing 

much of the flank. Most of these ribs terminate in small 

rounded lateral nodes. From the row of lateral nodes 

secondary ribs extend on across the venter where they 

number about 30 on the last half whorl. The lateral

FIGDRE 4. Sutures of Trachyacaphites spiniger (Schluter) subsp. 

porchi Adkins, X2. A, Plesiotype USNM 132322 (pi. 2, fig. 19). 

B, Plesiotype USNM 132323 at diameter of 38 mm (pi. 2, figs. 

20-23).

row of nodes is present on the entire outer septate 

whorl. On the younger half of the whorl small rounded 

ventrolateral nodes ordinarily appear. On a few individuals ventrolateral and ventral nodes may occur along 

with the lateral nodes around the entire outer septate 

whorl.

All living chambers (six) at hand are badly crushed. 

Ribs are usually very weak and number 45 to 55. 

Clearly defined primary ribs are present only on the 

older part. Nodes are conspicuous and ordinarily occur 

in three almost equally spaced rows, umbilicolateral, 

lateral, and ventrolateral. All nodes are of similar size 

and for the most part are rounded, and each row extends 

to the aperture. The nodes in the umbilicolateral row 

number 4 to 7, and those in the lateral row number 10 

to 12. About 10 ventrolateral nodes are present on one 

individual, but the number on other specimens could 

not be determined. One specimen (pi. 4, fig. 13) is unusual by having a row of nodes between the lateral and 

ventrolateral rows on the younger part of the last septate whorl. Another speciment (pi. 4, fig. 12), that may 

be a large variant of this species, has conspicuous ribbing on the living chamber.

The holotype (pi. 4, fig. 10) is a crushed adult that 

retains its shell material. It is 73 mm high and 64 mm 

wide. The living chamber has 7 umbilicolateral nodes 

and 11 lateral nodes. The distance separating the umbilicolateral row from the lateral row is a little more 

than that separating the lateral and ventrolateral rows.

Sutures of two paratypes (USNM 132336,132340) are 

shown on text figure 5. The sutures are similar to those 

of Trachyscaphites spiniger.
E12 CONTRIBUTIONS TO PALEONTOLOGY

FIGURE 5. Sutures of Trachyscaphites praespiniger Cobban 

and Scott, n. sp., X2. A, Paratype USNM 132340 at 

diameter of 19 mm. B, Paratype USNM 1'32336 at diameter of about 48 mm (pi. 4, fig. 13).

Trachyscaphites praespiniger differs readily from 

other species of Trachyscaphites by the lesser number 

of rows of nodes and by the presence on most specimens 

of only one row of nodes (lateral) entirely around the 

last septate whorl. The ribbing on the living chamber 

is sparse in contrast to that on T. spiniger.

Types: Holotype, USNM 132333; paratypes, USNM 132334- 

132340.

Occurrences: Montana, loc. 2; South Dakota, loc. 5; Wyoming, 

Iocs. 6-8; Utah, loc. 9; Colorado, Iocs. 15-19.

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MULTINODOSE SCAPHITTD CEPHALOPODS E13

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PLATES 1-4
PLATE 1

[All figures natural slzel

FIGURES 1-7. Trachyscaphites redbirdensis Cobban and Scott (p. E7).

1. Rear view of the last septate whorl of a paratype from a limestone concretion 218 feet above the base of the 

Red Bird Silty Member of the Pierre Shale at loc. 4 (text fig. 1). USNM 132310.

2. Rear view of part of the living chamber of a paratype from a limestone concretion 188 feet above the base of 

the Red Bird Silty Member of the Pierre Shale at loc. 3 (text fig. 1). USNM 132313.

3-5, 7. Top, rear, side, and front views of the holotype from the same loc. as figure 1. USNM 132309.

6. View of a fragment of the living chamber of a paratype oriented to show the differences in size of the 

umbilicolateral, lateral, ventrolateral, and ventral nodes. From the same locality as figure 1. USNM 132311.
GEOLOGICAL SURVEY PROFESSIONAL PAPER 483-E PLATE 1

TRACHYSCAPHITES REDBIRDENSIS COBBAN AND SCOTT
PLATE 2

[All figures natural size]

FIGURES 1-23. Trachyscaphites spiniger (Schliiter) subsp. porchi Adkins (p. E10).

I-3. Side, front, and rear views of the septate coil of the slender form of the species from the Wolfe City Sand

Member of the Taylor Marl at USGS Mesozoic loc. D4006, on Texas Highway 34, 1.3 miles west of Ladonia,

Fannin County, Tex. USNM 132314.

4, 5. Rear and side views of a small specimen from the same locality. USNM 132315.

6, 7. Side and top views of an unusually small adult living chamber from the same locality. USNM 132316. 

8-10. Side, rear, and front views of an adult from the Wolfe City Sand Member of the Taylor Marl at USGS

Mesozoic loc. 9711, at a cut of the Gulf, Colorado & Santa Fe Railway 1.5 miles northeast of Wolfe City,

Hunt County, Tex. USNM 132319.

II-14. Side, rear, front, and top views of the internal mold of a very slender adult from the Pecan Gap Chalk

Member of the Taylor Marl at USGS Mesozoic loc. 9713, near the Gulf, Colorado & Santa Fe Railway about

0.8 mile east of Pecan Gap, Delta County, Tex. USNM 132320. 

15, 16. Rear and side views of the septate coil of a specimen from the same locality as figures 1-3 showing the

furrows between groups of ribs. USNM 132317.

17, 18. Rear and side views of another specimen from the same locality. USNM 132318. 

19. Rear view of a stout septate specimen from the Pecan Gap Chalk Member of the Taylor Marl at USGS

Mesozoic loc. 9561, 3 miles southeast of Wolfe City, Hunt County, Tex. For suture, see text figure 4A.

USNM 132322. 

20-23. Top, side, front, and rear views of a topotype, a septate internal mold from the Pecan Gap Chalk

Member of Taylor Marl at USGS Mesozoic loc. D104 on the Austin-Manor road 1.7 miles east of bridge

over Walnut Creek, Travis County, Tex. For suture, see text figure 4£. USNM 132323.
GEOLOGICAL SURVEY PROFESSIONAL PAPER 483-E PLATE 2

snt ^fr*^**

15

\

t ^i

» A£t -3 

« < «:> »

, ;v«-s- i&^j \^*->-

13

20 21 22 

TRACHYSCAPHITES SPINIGER (SCHLUTER) SUBSP. PORCHI ADKINS
PLATE 3

[All figures natural size] 

FIGURES 1-11. Trachyscaphites spiniger (Schliiter) subsp. porchi Adkins (p. E10).

1. Side view of a crushed adult, an internal mold, showing the small size of the lateral nodes. From the Anacacho 

Limestone at USGS Mesozoic loc. 7651, on west-flowing branch of Salado Creek about 7 miles northeast of San 

Antonio, Bexar County, Tex. USNM 132324.

2. Side view of another adult, from the same locality, showing very large ventrolateral nodes in contrast to the 

small lateral nodes. Only two of the ventral nodes on the living chanber are visible. USNM 132325.

3. Side view of another adult, from the same locality, showing large umbilicolateral and ventrolateral nodes in 

contrast to the much smaller lateral nodes. USNM 132326.

4. Rear view of a crushed septate coil from locality 10 (text fig. 1). USNM 132327.

5. Side view of a crushed septate coil with its shell material from locality 13 (text fig. 1). USNM 132330.

6. Side view of a rubber cast of part of an adult from the same locality as figure 4. USNM 132328.

7. Side view of a crushed adult from the same locality. USNM 132329.

8. Top view of the younger part of a stout living chamber, an internal mold, from the Pecan Gap Chalk Member 

of the Taylor Marl, on the Cox farm 3 miles southeast of Wolfe City, Hunt County, Tex. Number 7608 in the 

private collection of James P. Conlin, Fort Worth, Tex. Plastotype, USNM 132331.

9. Side view of part of an adult associated with Inoceramus azerbaidjanensis Aliev, from the Wolfe City Sand 

Member of the Taylor Marl, at USGS Mesozoic loc. 9710 at a cut along the Gulf, Colorado & Santa Fe Railway 

1.5 miles northeast of Wolfe City, Hunt County, Tex. USNM 132332.

10. 11. Side and rear views of an uncrushed specimen, an internal mold, showing the septate coil and the older part 

of the living chamber. From the Pecan Gap Chalk Member of the Taylor Marl, at USGS Mesozoic loc. 9713, 

near the Gulf, Colorado & Santa Fe Railway about 0.8 mile east of Pecan Gap, Delta County, Tex. USNM 

132321.
GEOLOGICAL SURVEY PROFESSIONAL PAPER 483-E PLATE 3

TRACHYSCAPHITES SPINIGER (SCHLUTER) SUBSP. PORCHI ADKINS
PLATE 4

[All figures natural size]

FIGURES 1-11, 13. Trachyscaphites praespiniger Cobban and Scott, n. sp. (p. Ell).

1, 2. Rear and side views of the outer septate whorl of a paratype retaining part of the shell material, from

a limestone concretion at loc. 6 (text fig. 1). USNM 132337.

3, 4. Rear and side views of the next inner whorl of the paratype shown on figures 1, 2. USNM 132337. 

5, 6. Side and front views of part of a paratype, from the same locality, showing the numerous nodes on the

living chamber in contrast to the fewer nodes on the septate coil. USNM 132338.

7. Side view of a shell-covered paratype, from loc. 17 (text fig. 1), that shows narrow furrows bounding some 

of the primary ribs. USNM 132334.

8. 9. Front and side views of a paratype, a septate coil, from loc. 9 (text fig. 1), showing the persistence of the 

lateral row of nodes. USNM 132339.

10. Side view of the holotype from loc. 17 (text fig. 1). USNM 132333.

11. Side view of a crushed paratype, from the same locality, that retains most of the shell material. USNM

132335. 

13. Side view of another crushed adult from this locality showing an additional row of nodes on the septate

coil. The suture is shown in text figure 5B. USNM 132336. 

12. Trachyscaphites cf. T. praespiniger Cobban and Scott, n. sp. (p. Ell).

Side view of a rubber cast of a large crushed and broken adult from loc. 5 (text fig. 1). This specimen has

stronger and denser ribbing than that on the typical form of the species. USNM 132372.
GEOLOGICAL SURVEY PROFESSIONAL PAPER 483-E PLA.TE 4

12 13 

TRACHYSCAPHITES PRAESPINIGER COBBAN AND SCOTT