Marine Jurassic Gastropods, 

Central and Southern Utah 

GEOLOGICAL SURVEY PROFESSIONAL PAPER 503-D 

Marine Jurassic Gastropods, 

Central and Southern Utah 

By NORMAN F. SOHL 

CONTRIBUTIONS TO PALEONTOLOGY 

GEOLOGICAL SURVEY PROFESSIONAL PAPER 503-D 

A descrzption of I9 species of gastropods 

from the Ba;"ocian to Callovian rocks of 

Utah, supplemented by a discussion of the 

Jurassic gastropod fauna of North America 

UNITED STATES GOVERNMENT PRINTING OFFICE, WASHINGTON : 1965 
UNITED STATES DEPARTMENT OF THE INTERIOR 

STEWART L. UDALL, Secretary 

GEOLOGICAL SURVEY 

Thomas B. Nolan, Director 

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

Washington, D.C. 20402 - Price 45 cents (paper cover) 
CONTENTS 

Page 

Abstract------------------------------------------------------------------- I>1 

Introduction_______________________________________________________________ 1 

Analysis of the gastropod fa una_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 4 

Abundance_____________________________________________________________ 5 

Preservation of the fossils, and notes on ecology____________________________ 6 

Geographic and stratigraphic distribution__________________________________ 7 

Survey of Jurassic gastropods of North America________________________________ 8 

~exico________________________________________________________________ 8 

United States (conterminous)_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 8 

Gulf coast_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 8 

VVestTexas-------------------------------------------------------- 9 VV estern interior_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 9 

Pacific coast------------------------------------------------------- 12 

Canada---------------------------------------------------------------- 12 

Alaska________________________________________________________________ 12 

SummarY-------------------------------------------------------------- 13 

Systematic paleontology_____________________________________________________ 15 

References cited_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 24 

Index--------------------------------------------------------------------- 27 

ILLUSTRATIONS 

[Plates follow index] 

PLATE 1. Trochacea?, Teinostomopsis?, Ooliticia?, Pleurotomaria?, Nododelphinula?, Amberleya?, Cylindrobullina?, Neridomus?, and Symmetrocapulus? 

2. Lyosoma. 

3. Rhabdocolpus, Pseudomelania?, Procerithium? and Neritina? 

4. Cossmannea, Globularia?, Tylostoma? 

5. Specimens of Carmel limestone. 

Page 

FIGURE 1. Index map of central and southwestern Utah____________________________________________________________ ]) 2 

2. Geographic and stratigraphic distribution of the Gastropoda of the Carmel Formation________________________ 5 

TABLES 

Page 

TABLE 1. Localities at which marine gastropods of Jurassic age have been collected in central and southern Utah__________ I>3 

2. Abundance of the Gastropoda of the Carmel Formation_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 6 

ni 

CONTRIBUTIONS TO PALEONTOLOGY 

MARINE JURASSIC GASTROPODS, CENTRAL AND SOUTHERN UTAH 

By NoRMAN F. SoHL 

ABSTRACT 

This ,paper describes a gastropod fauna of 19 species assigned 

to 17 genera from the lower limy units of the Carmel Formation and from the Twelvemile Canyon Member of the Arapien 

Shale (Bajocian to Callovian) in central and southwestern 

Utah. These descriptions constitute the first report for most 

of the genera from the Jurassic of North America. The Carmel 

gastropod fauna is a shallow-water one dominated by Archaeogastropoda and Mesogastropoda, primarily the cerithiaceans, 

naticaceans, and neritaceans such as Lyosmna. Neogastropoda 

are absent, and Euthyneura are represented only by the nerineids 

and the cephalas,pid genus OylindrobulUna. Of special note is 

the neritid Lyoswna, which heretofore has been thought to lack 

an inner lip septum. Silicified specimens retain such a lip and 

show that its loss is probably due to differential replacement of 

shell layers. 

Gastropods are most common in the central area of outcrop 

of the Carmel Formation and lessen in diversity and abundance 

in the thinner sandier, nearer shore sediments to the east. 

The fauna is most similar to that found in member B of the 

Twin Creek Limestone of Utah, Idaho, and Wyoming; but it also 

has a close relationship to that in the Gypsum Spring Formation 

and "Lower Sundance Formation" of Wyoming. 

A survey of the Jurassic gastropods of North America indicates that they are not so diverse as are those of Europe. 

Taxonomically, they are dominated by the Archaeogastropoda 

(especially Neritacea and Amberleyacea) and Mesogastropoda 

(primarily Pseudomelaniacea and Ceritheacea). No Neogastropoda are present. 

The Jurassic gastropods are very provincial. The gulf coast 

and west Texas gastropod faunas are similar in some respects, 

but have no species in common with those of the western interior. 

Similarly, the Alaskan gastropod fauna is distinct from those 

faunas to the south. Such differences are seen even at the 

family level where the Neritidae and Nerineacea, so common in 

the southern faunas, are absent or poorly represented in Alaska. 

In Alaska the Purpurinidae and Amberleyiidae are common 

but decrease in abundance southward to Mexico. 

In terms of age the Late Jurassic is the time of greatest 

gastropod diversity in the gulf coast and west Texas, but in the 

western interior and Alaska, the Middle Jurassic (Bathonianlower Callovian) interval shows the greatest flowering of 

gastropod faunas. 

INTRODUCTION 

Little information on the nature of the 1nolluscan 

fauna of the Carmel Formation of central and southern 

Utah has been published. Fieldwork, primarily by 

geologists of the U.S. Geological Survey, during recent 

years has provided sufficient collections and detailed 

stratigraphic information to make a study of this fauna 

especially profitable. 

This report on the gastropods of the Carmel Formation and the Twelvemile Canyon Member of the Arapien 

Shale supplements the report by Imlay (1964) on the 

pelecypods. He provided an outline of the stratigraphy, 

age, and correlation of the Carmel Formation and discussed the relationships of the collecting localities. The 

stratigraphy and lithology of the units of the formation 

were described by Baker, Dane, and Reeside (1936) and 

summarized by Wright and Dickey ( 1958, 19,63). 

The Carmel Formation may be divided into two units. 

A lower limy unit is dominated by gray limestone and 

shale and, according to Imlay ( 1964, p. C3-C5), is of 

Bajocian age. An upper unit is dominated by claystone, siltstone, and gypsum but locally includes some 

sandstone. The whole formation becomes thinner, 

sandier, and redder toward the east and finally changes 

into reel beds. Frmn the featheredge in southeastern 

lTtah, the formation thickens and becomes increasingly 

calcareous to the northwest, and in Sanpete and Juab 

Counties the total thickness of the equivalent Arapien 

Shale may reach 3,000 feet or more (Wright and Dickey, 

1963). 

All the gastropods have come from the lower limy 

unit of the Carmel Formation, and like the pelecypods 

(Imlay, 1964), they are most abundant in the middle 

area (fig. 1), which is approximately 40 miles wide and 

trends southwestward along the west side of the San 

Rafael Swell. Abundance of fossils diminishes to the 

east as the units thin and to the west as they thicken. 

The Arapien Shale consists of a lower gray calcareous shale called the Twelvemile Canyon Member 

and an upper red and gray siltstone and shale member 

called the Twist Gulch Member. In aggregate thickness they may reach 10,000 feet. Gastropods are rare 

in the formation and occur only in the Twelverriile 

Canyon Member. Correlation with the Carmel Formation must rest primarily on fauna other than gastropods. 

The gastropod fauna of the Carmel Formation is 

D1 
D2 CONTRIBUTIONS TO PALEONTOLOGY 

small, consisting of 19 species assigned to 17 genera. 

There are a few other gastropods in the fauna, but they 

are too poorly preserved to merit even generic assignment. The gastropods all come from the lower limy 

unit of the Carmel Formation (Imlay, 1964) and from 

equivalent units of the Arapien Shale. This unit of the 

Carmel Formation has yielded an abundance of fossils, 

but the gastropods usually are poorly preserved.-

As is· shown on figure 1 and table 2, gastropods have 

been collected at 42 localities in the Carmel Formation 

and Arapien Shale. (See table 1.) Sixty-one collec113° 

J U A B C 0 U N T Y 

M L L A R 

B E A V E R C 

R 0 N C 0 

37° ---------------

tions, many representing different stratigraphic levels 

at the 42 localities, are reported on herein. 

Special thanks are due my colleague R. W. Imlay 

of the U.S. Geological Survey, who first interested me 

in the present study. He has not only aided as a critical 

reviewer but has also guided me to many of the collecting localities and tutored me in Jurassic stratigraphy. 

James C. Wright, also of the Survey, whose fieldwork 

precipitated the present paper, is also due many thanks 

for serving as a field companion, guide, and technical 

reviewer. 

COUNTY 

0 U N T Y 

FIGuRE 1.-Map of central and southwestern Utah showing localities at which Carmel and Arapien gastropods have been 

found. Numbers indicate collection localities referred to in text. 
MARINE JURASSIC GASTROPODS, CENTRAL AND SOUTHERN UTAH D3 

TABLE !.-Localities at which marine gastropods of Jurassic age TABLE !.-Localities at which marine gastropods of Jurassic age 

have been collected in central and southern Utah have been collected in central and southern Utah-Continued 

usns 

Locality Mesozoic on fig. 1 locality 

1 17269 

2 21448 

3 21647 

4 21446 

5 17030 

6 16395 

7 A 18670 

7B 18671 

8 19428 

9A 25672 

9B 27474 

9C 28461 

9D 28462 

10 27469 

11 17495 

12 16701 

13A 16702 

13B 28493 

14A 28475 

Collector, year of collection, description of locality, and 

stratigraphic assignment 

S. L. Schoff, 1936. Red Creek, SE}~ sec. 9, T. 

12 S., R. 2 E., Juab County. Arapien Shale. 

C. T. Hardy, 1948. 2.7 miles northwest of 

Mayfield, south of Twelvemile Creek, SE}~NW}~ sec. 19, T. 19 S., R. 2 E., Sanpete 

County. Arapien Shale, about 600(?) ft 

below Twist Gulch Member. 

R. W. Imlay, John Mcintyre, and C. T. Hardy, 

1949. 2.5 miles northwest of Mayfield, south 

of Twelvemile Creek, SE}~SW%, sec. 19, T. 

19 S., R. 2 E., Sanpete County. Twelvemile 

Canyon Member of Arapien Shale, about 

1,800(?) ft below base of Twist Gulch Member. 

C. T. Hardy, 1948. 1.9 miles northwest of Mayfield, NE}~NW% sec. 30, T. 19 S., R. 2 E., 

Sanpete County. Arapien Shale, about 

1,800(?) ft below Twist Gulch Member. 

E. M. Spieker, 1930. Near Mayfield-Gunnison 

road about 1 mile from Mayfield, Wasatch 

Plateau, Sanpete County. Arapien Shale. 

J. W. Young 1933. Limestone Gulch, 8 miles 

south of Marysvale, sec. 20, T. 28 S., R. 4 W., 

Piute County. Arapien Shale. 

P. E. Dennis, 1941. Mineral Gap, Beaver 

County. 

P. E. Dennis, 1941. Mineral Gap, Beaver 

County. 

H. J. Bissell, 1944. Northeast of Cedar City, sec. 1, T. 36 S., R. 11 W., Iron County. 

Carmel Formation, main Pentacrinus unit, 

from lower part of 23 ft of fossiliferous limestone lying 231 ft above base of Carmel. 

R. W. Imlay, Paul Averitt, and Hector Ugalde, 

1955. North side of Shurtz Creek about 6 

miles south of Cedar City, sees. 11 and 14, T. 

37 S., R. 11 W., Iron County. Carmel Formation, from pebbly oolitic limestone in lower 

part of formation about 235 ft above base. 

J. C. Wright and R. P. Snyder, 1959. On crestline of north pyramid near Shurtz Creek, 

SE%SE%, sec. 11, T. 37 S., R. 11 W., Iron 

County. Carmel Formation, 272-282 ft 

above base. 

R. W. Imlay and N. F. Sohl, 1961. North side 

of Shurtz Creek about 6 miles south of Cedar 

City, sees. 11 and 14, T. 37 S., R. 11 W., 

Iron County. Carmel Formation. 

R. W. Imlay and N. F. Sohl, 1961. Iron 

County. Same locality as USGS loc. 28461. 

Ca:!'mel Formation, 229-255 ft above base. 

J. C. Wright and R. P. Snyder, 1959. On southeast spur of knoll near Sweetwater Spring 

about 4 miles southeast of Kanarraville, NE% sec. 7, T. 38 S., R. 11 W., Iron County. 

Carmel Formation, 260-305 ft above base. 

H. E. Gregory, 1937, West of Pintura, sec. 32, 

T. 39 S., R. 13 W., Washington County. 

Carmel Formation. 

C. E. Dobbin, 1934. Sec. 22, T. 41 S., R. 13 W., 

Washington County. Carmel Formation. 

C. E. Dobbin, 1934. NE% sec. 34, T. 40 S., R. 

14 W., Washington County. Carmel Formation. 

R. W. Imlay and N. F. Sohl, 1961. Danish 

Ranch section, NE corner of sec. 34, T. 40 S., 

R. 14 W., Washington County. Carmel 

Formation, 60 ft above base of limestone. 

R. W. Imlay and N. F. Sohl, 1961. Cottonwood 

Canyon, sec. 3, T. 41 S., R. 15 W., Washington 

County. Carmel Formation, oolitic and 

crinoidallimestone float, probably from 170ft 

above base of limestone but possibly from a unit 240 ft above base. 

usns 

Locality Mesozoic on fig. 1 locality 

14B 28477 

15A 28463 

15B 28465 

15C 28467 

16 28470 

17 A 20351 

17B 25684 

18A 25670 

18B 25678 

18C 25680 

19A 13529 

19B 28480 

20 15551 

21 16202 

22 11137 

Collector, year of collection, description of locality, and 

stratigraphic assignment 

R. W. Imlay and N. F. Sohl, 1961. Cottonwood 

Canyon, sec. 3, T. 41 S., R. 15 W., Washington 

County. Carmel Formation, from oolitic 

limestone zone about 140 ft above base of 

limestone member. 

R. W. Imlay and N. F. Sohl, 1961. West side 

of Santa Clara River 1% miles south of 

Gunlock near center sec. 32, T. 40 S., R. 17 W., 

Washington County. Carmel Formation, 287 

ft above base. 

R. W. Imlay and N. F. Sohl, 1961. West side of 

Santa Clara River 1% miles south of Gunlock near center sec. 32, T. 40 S., R. 17 W., 

Washington County. Float from oolitic 

sandstone capping ridge about 350 ft above 

base of limestone member of Carmel Formation. 

R. W. Imlay and N. F. Sohl, 1961. West side of 

Santa Clara River 1% miles south of Gunlock near center sec. 32, T. 40 S., R. 17 W., 

Washington County. Limestone member of 

Carmel Formation, 430ft above base. 

R. W. Imlay and N. F. Sohl, 1961. Tributary on northeast side of Buckhorn Wash at 

crossing of road from Woodside to Castledale, sec. 8, T. 19 S., R. 11 E., Emery County. 

Carmel Formation. 

J. B. Reeside, Jr., and R. W. Imlay, 1946, Head 

of Buckhorn Wash, sec. 13, T. 19 S., R. 10 E. 

Emery County. Carmel Formation, platy 

limestone about 25ft above base. 

R. W. Imlay, 1955. SE}~ sec. 18, T. 19 S., R. 

11 E., to SE% sec. 13, T. 19 S., R. 10 E., 

Emery County. Carmel Formation, 20-40 

ft above base. 

R. W. Imlay, 1955. On small ridge just south 

of road in NE~~NWX sec. 17, T. 19 S., R. 11 

E., Emery County. Carmel Formation, 

about 75ft above base. 

R. W. Imlay, 1955. Near head of small gully 

draining westward into southwestward-trending tributary of Buckhorn Wash, NE% sec. 18, T. 19 S., R. 11 E., Emery County. 

Carmel Formation, ledge-forming sandy limestone about 40ft above base. 

R. W. Imlay, 1955. On northwest side of gulch 

in northeastern and central _parts of sec. 18, 

T. 19 S., R. 11 E., Emery County. Carmel 

Formation, ledge of sandy limestone 20-30 ft 

above base. 

James Gilluly and E. T. McKnight, 1925. Rim 

of Eagle Canyon, just below road from 

Rochester (Moore) to Horn Silver Prospect, 

approximately sec. 33, T. 22 S., R. 9 E. 

(unsurveyed), Emery County. Basal limestone of Carmel Formation. 

R. W. Imlay and N. F. Sohl, 1961. Eagle 

Canyon Lookout, sec. 33, T. 22 S., R. 9 E., 

Emery County. Carmel Formation about 

20ft above base in bed of limestone containing 

very abundant fossil fragments just below 

green shale. 

L. G. Henbest and A. A. Baker, 1930. Side of 

road on east side of Iron Wash, SE% sec. 34, 

T. 23 S., R. 13 E., Green River Desert, Emery 

County. Carmel Formation, about 90 ft 

above base. 

L. G. Henbest, 1930. Green River Desert, NEX sec. 19, T. 24 S., R. 13 E., Emery County. 

Carmel Formation. 

C. J. Hares, 1921. East side of San Rafael 

Swell near Temple Mountain, sec. 34, T. 24 

S., R. 12 E., Emery County. Carmel Formation limestone at base. 
D4 CONTRIBUTIONS TO PALEONTOLOGY 

TABLE I.-Localities at which marine gastropods of Jurassic age 

have been collected in central and southern Utah-Continued 

Locality 

on fig. 1 

23 

24 

25 

26A 

26B 

27 

28 

29 

30 

31A 

31B 

31C 

32 

33 

34A 

usns 

Mesozoic 

locality 

17412 

10116 

24258 

25669 

28456 

10436 

9112 

26308 

28492 

25671 

26307 

28468 

26676 

16624 

28473 

Collector, year of collection, description of locality, and 

stratigraphic assignment 

A. A. Baker, 1930. About 500 ft east of 

Swazey's Seep, Green River Desert, Emery 

County. Upper third of Carmel Formation, 

oolitic limestone in gypsiferous claystone. 

W. B. Emery, 1917. Hanksville road, 2 miles 

south of Straight Wash, Green River Desert, 

Emery County. Carmel Formation. 

J. F. Smith, 1952. About 7~ mile west of Sun 

Glo Park (in Fish Lake National Forest), Capitol Reef area, SW7~ sec.,31, T. 28 S., R. 4 E., 

Wayne County. Carihel Formation, about 

40-60 ft above base. 

R. W. Imlay, 1955. ~ mile west of Teasdale, sec. 17, T. 29 S., R. 4 E., Wayne County. 

Carmel Formation, oolitic limestone about 44 

ft above top of Navajo Sandstone, or 7 ft 

above top of red unit at base of Carmel. 

R. W. Imlay and N. F. Sohl, 1961. West of 

Teasdale, between town and Blueberry Creek. SEXSE7~ sec. 18, T. 29 S., R. 4 E., Wayne 

County. Carmel Formation. 

E. F. Davis, 1920. East side of the Water Pocket fold just north of Capitol Wash, NW7~ 

sec. 10, T. 30 S., R. 7 E., Wayne County. 

Carmel Formation. 

B. S. Butler, 1914. On trail about midway between Hanksville and Robbers Roost, NEX sec. 31, T. 28 S., R. f3 E., Wayne County. 

Carmel Formation, just above Navajo Sandstone. 

R. W. Imlay, 1956. On west side of gulch 

draining southward into Antimony Creek in 

west-central part of sec. 20, T. 31 S., R. 1 W., 

Garfield County. Carmel Formation, 20-30 

ft above base. 

N. F. Sohl, 1961. Hell's Backbone, about 600 

ft south of pre-1961 Hell's Backbone Bridge on west side of road, approximately sec. 5, T. 

33 S., R. 3 E., Garfield County. Carmel 

Formation, about 15-20 ft above base. 

R. W. Imlay, 1955. Deep Creek, about 1 mile 

southeast of road to Hell's Backbone Ridge 

and about 15 miles north of Escalante, Garfield County. Carmel Formation, from basal 

bed of 15-ft limestone ledge about 20ft above 

top of Navajo Sandstone. 

R. W. Imlay, J. D. Strobell, Jr., J. C. Wright, 

and D. D. Dickey, 1956. On Deep Creek 7~ 

mile southeast of road to Hell's Backbone 

Ridge, east-central part of sec. 15, T. 33 S., R. 

2 E., Garfield County. Carmel Formation, 

shaly limestone about 12 ft above Navajo Sandstone. 

R. W. Imlay and N. F. Sohl, 1961. East side 

of Deep Creek 4,000 ft downstream from 

road crossing of Deep Creek by the road to 

Hell's Backbone Ridge, sec. 15, T. 33 S., R. 

2 E., Garfield County. Same as USGS loc. 

26307. Carmel Formation. 

R. W. Imlay, 1955. In Paria Valley, about 5 

miles south of Cannonville, Kane County. 

Carmel Formation, about 12 fti above base of 

formation in gray shaly limestone. (See 

Gregory, 1951, p. 58.) 

C. D. Walcott, 1879. Upper end of box canyon 

below volcano, Kanab Creek valley, Kane 

County. (Probably same as locs. 34A, 34B.) 

Carmel Formation. 

R. W. Imlay and N. F. Sohl, 1961. Kanab 

Creek, west fork at box canyon just below 

Glendale road and below lava flow, W~ sec. 3, 

T. 41 S., R. 6 W., Kane County. Carmel 

Formation, about 10-15 ft below top of limestone member. 

TABLE I.-Localities at which marine gastropods of Jurassic age 

have been collected in central and southern Utah-Continued 

usns 

Locality Mesozoic Collector, year of collection, description of locality, and on fig. 1 locality stratigraphic assignment 

34B 28496 R. W. Imlay and N. F. Sohl, 1961. Kanab 

Creek, west fork at box canyon just below 

Glendale road and below lava flow. W}~ sec. 3, T. 41 S., R. 6 W., Kane County. Carmel 

Formation, about 10-15 ft below top of limestone member. 

35 963 T. W. Stanton, 1892. NWX sec. 25, T. 40 S., 

R. 7 W., Glendale area, Kane County. 

Carmel Formation. 

36 15498 J. B. Reeside, Jr., and others, 1930. West of 

bridge at south end of Mount Carmel, W~ 

sec. 18, T. 41 S., R. 7 W., Kane County. 

Carmel Formation, 15 ft above gypsum bed 

at Mount Carmel. 

37A 28471 R. W. Imlay and N. F. Sohl, 1961. On east 

side of U.S. Highway 89 just south of pre-1960 · bridge, sec. 30, T. 41 S., R. 7 W., Kane 

County. Carmel Formation, about 93 ft 

above base of limestone member (at top of 

"lower lime"). 

37B 28474 R. W. Imlay and N. F. Sohl, 1961. On east 

side of U.S. Highway 89, just south of pre-1960 

bridge, sec. 30, T. 41 S., R. 7 W., Kane 

County. Carmel Formation, about 35 ft 

below top of limestone member. 

38A 28494 R. W. Imlay and N. F. Sohl, 1961. South side 

of canyon of Virgin River at a cabin, Orderville quadrangle, sec. 33, T. 39, S., R. 9 W., 

Kane County. Carmel Formation, 20-30 ft 

below top of limestone member and 8-18 ft 

above top of oolitic ledge former. 

38B 28495 R. W. Imlay and N. F. Sohl, 1961. South side 

of Virgin River, sec. 33, T. 39 S., R. 9 W., 

Kane County. Carmel Formation, 20-30 ft 

below top of limestone member. 

39 28479 R. W. Imlay, 1961. Orderville Canyon near SE cor. sec. 19, T. 40 S., R. 9 W., Kane 

County. Carmel Formation, thin-bedded 

cream-weathering limestone in uppermost 10 

ft of formation. 

40 17351 H. E. Gregory, 1936. Jolly Gulch, Zion Park, 

approximately SWX sec. 8, T. 41 S., R. 9 W., 

Kane County. Carmel Formation, top limestone below red sandstone. 

41 17054 H. E. Gregory, 1934. East entrance Zion Park, 

approximately W~ sec. 18, T. 41 S., R. 9 W., 

Kane County. Carmel Formation, near con- tact with Navajo Sandstone. 

42 17494 H. E. Gregory, 1937. Box Mesa, near Parinuweap Canyon, north of Virgin River, NEX sec. 31, T. 41 S., R. 9 W., Kane County. 

Carmel Formation. 

ANALYSIS OF THE GASTROPOD FAUNA 

The streptoneurous or prosobranch snails dominate 

the gastropod fauna of the Carmel Formation. Of the 

10 superfamilie~ and 12 fa.milies represented (fig. 2) 

only Oylindrobullina? sp. ( Acteonac.ea, Acteonidae) 

and 0 088717.tann.ea ( N erineacea) represent the subclass 

Euthyneura. Of the Streptoneura the orders Archaeogastropoda and Mesogastropoda are about equally diverse, but the order Neogastropoda is absent. This is 

not unusual, as representatives of this order were not 

abundant in marine faunas until Late Cretaceous (Sohl, 

1964, p. 157). 
MARINE JURASSIC GASTROPODS, CENTRAL AND SOUTHERN UTAH D5 

Central and southern Utah Northern SouthWestern Middle Eastern Utah eastern Wyoming 

area area area Utah 

Arapien Carmel Formation "Lower Sundance 

Shale Limy lower unit Gypsum Twin Formation" 

Twin Creek Spring Creek Canyon Twelvemile ~ ,.... Q) Q) ,.... Limestone Forma- Lime- Undiffer- Springs Canyon Q) "C Q) =o Q) tion stone 3: a. 3: 0. "'0 "'0 a. entiated Sandstone Member 0 ~ a. 0 _I ::J _J ~ ::J Member 

Superfamily Pleurotomariacea 

Family Pleurotomariidae 

Pleurotomaria? sp. -------------- ...;..___ 

Superfamily Patellacea 

Family Symmetrocapulidae 

Symmetrocapulus? corrugatus Sohl, n. sp. ~ 

Superfamily Trochacea 

Family Cyclostrematidae 

Teinostomopsis? sp. ------------- f-- X 

Trochacea? sp. ---------------- 1----

Superfamily Neritacea 

Family Neritidae 

Lyosoma powelli White ---------- I-- X X X X X X 

Lyosoma enoda Soh I, n. sp. --------- X ? -- 1-- ? X ? X ? 

Neritina phaseolaris White --------

Neridomus? sp. -------------- X 1--

Neritid gastropods -------------- X X 

Superfamily Amberleyacea 

Family Nododelphinulidae 

Nododelphinula? sp. ------------- - X X 

Family Amberleyidae 

Amberleya? sp. -------------- - Ooliticia? sp. ----------------- - Superfamily Cerithiacea 

Family Procerithiidae 

Rhabdocolpus viriosus Sahl, n. sp. ----- X 

Procerithium? sp. ---------------- ~ 

Su perfa mi ly Pseudomelan i ace a 

Family Pseudomelaniidae 

Pseudomelania? sp. --------------- 1---- X 

Superfamily Naticacea 

Family Naticidae 

Tylostoma? sp. ----------------- ? ? ? 

Family Ampullinidae 

Subfamily Globulariinae 

Globularia? sp. ------------------

Naticiform gastropods indet. ------ X -- ? 

Superfamily Nerineacea 

Family Nerineidae 

Cossmannea imlayi Sohl, n. sp. ------ X X X 

Cossmannea? kanabensis Sohl, n. sp. --- - Nerineid gastropods indet.------

Superfamily Actaeonacea 

Family Acteonidae 

Cylindrobullina? sp. -------------- X X 

FIGURE 2.-Geographic and stratigraphic distribution of the Gastropoda of the Carmel Formation. Occurrence indicated 

by X. Range of species shown by heavy line. 

A general paucity of species is the salient characteristic of, this otherwise typical Jurassic gastropod assemblage. This lack of diversity most probably reflects the 

ecologic control of the warm shallow, perhaps somewhat 

hypersaline, waters of a Jurassic interior seaway. 

ABUNDANCE 

The abundance of specimens per taxon by locality is 

given in table 2. The numbers give only a rough approximation of relative abundance, however, as many 

1nore specimens could be collected a.t many localities. 
D6 CONTRIBUTIONS TO PALEONTOLOGY 

TABLE 2.-Abundance of the Gastropoda 

[Letters opposite specific name indicate abundance: R, rare (1-5 specimens) NC, 

Localities 

2 3 4 5 6 7A 7B 8 9A 9B 90 9D 9E 10 11 12 13A 13B 14A 14B 15A 15B 150 16 17 A 17B 18A 18B 

-------1--1----------------------~-------------------- Pleurotomaria? sp _________________________________________________________________________ ---- ---- ---- ________________ ---- ------ ------ ---- ---- ------ ---- Symmetrocapulus? cor- __________________________________________________________________ ---- ---- ---- ____ ---- ____ ---- ---- ------ ------ ---- ---- ------ ---- rugatus Sohl, n. sp. 

s~~~~~t~:~ ~m m= =~: :~: =m m~ ~~= =m ;~~=: ==:~ ~m=~ :~: ~~~: ~m :~: m= =m ~m ~m m: =~~ :;=: :~: :~~: :~~: jjjj ~m jj~~jj jjj= 

White. 

~~~ltr;:~:t:~.Pocts~===== ==== -~- ==== ==== -ii- ==== ==== ==== ====== ==== ====== ==== ====== ==== ==== ==== ==== ==== ==== ==== ==== ==== -ii- ====== ====== ==== ==== _ii ___ ::== 

lJr;::g::J[y~~n~~~~-=~~===== ==== :::: ==== ==== ==== ==== ==== ==== ====== ==== ====== ==== ====== ==== ==== ==== :::: :::: :::: ==== :::: :::: ==== ====== _R ___ ==== ==== ====== ==== ~~~~J~~~z::s-virio81i8 ____ :::: :::: :::: :::: :::: :::: :::: -ii- -No- -ii- -No- -ii- _ii ___ :::: :::: :::: :::: :::: :::: -ii- :::: :::: -;;-- _ii ___ :::::: :::: :::: :::::: :::: Soh!, n. sp. Procerithium? sp __________________________________________________ ------ ____ ------ ________ ---- ---- ---- ---- ---- ---- ---- ---- ------ ------ ---- ---- ------ ----

~~7~Err!tiJ~~::: :~: ~=~~ ~~~~ ::~~ =~~~ :~: ~~~= ~~=~ ~~~~~~ ~~~~ ~~~~~= ~~~~ =~~= :~: ~~=~ ~~=~ :~: ~~~= ~~~~ ~~~~ ~~~~ I ~~~~ ~~~::~ :~::: ;~; :~; ~==~~~ ;~; indet. Cossmannea imlayi Sohl, ____ ____ ____ ____ ____ ____ ____ ____ ______ ____ ______ ____ ______ ____ ____ ____ R R C ________________ ------ R ____ ---- NO ___ _ 

n.sp. 

Cossmannea? kanabensis ________________________________ ------ ____ ------ ____ ------ ---- ---- ---- ---- ---- ---- ---- ---- ---- ---- ------ ------ ---- ---- ------ ---- Sohl, n. sp. 

Nerineid gastropods ____________ ---- ---- ________ ---·· ------ ____ ------ ---- ------ ---- ---- ---- ---- ---- ---- ---- ---- ---- ---- ------ ------ ---- ---- ------ ---- indet. 

Cylindrobullina'! sp______ ____ ____ R ---- ____ ____ ____ R R R ------ R R ~ ---- R ---· ________ ---- R ____ A ------ R ---- ---- ------ ----

In addition, other collections were made by fieldmen 

whose concern was collecting a representative suite for 

the purpose of age determination. These collections 

naturally afford little basis for determining relative 

abundance. In spite of such drawbacks, certain species 

are obviously more abundant than others. 

The small gastropods of the "winnowed" (see notes 

on ecology in next section) fauna such as Oylindro"1ntllina? and Rhabdocolp,us (pl. 5) may be as numerous as 

all other mollusks combined. In the slabby limestones 

they occur in such profusion that they could be collected 

by the thousands. Hand specimens such as those illustrated on plate 5 show the concentrated occurrence of 

these species. Aside frmn these small shells, gastropods 

are less eommon than either pelecypods or crinoid columnal remains. 

Of the larger gastropods, Lyosoma enoda and L. 

powelli are the most widespread species, but specimens 

are few at any given locality. Whereas species such as 

Globularia ? sp. and 0 ossmannea imlayi are less widespread, they are locally abundant; and many more specimens than recorded on table 2 could be collected. The 

rarest genera such as N ododelphinula?, Ooliticia?, Symmetrocapulus ?, and Pleurotmnaria.rt are restricted in 

distribution and in numbers. 

No single locality contains a eomplete gastropod 

fauna. Some localities have yielded only single speeimens of indeterminable snails whe,reas others have a 

1naximun1 representation of nine types. The disparity 

is not entirely due to collecting failure, as at a number 

of localities at which pelecypods are conunon, no snails 

occur. Thus it is apparent that the Jurassic Carmel 

seas of central and southern Utah were not especially 

hospitable to gastropods. 

PRESERVATION OF THE FOSSILS, AND NOTES ON 

ECOLOGY 

Gastropods of the Carn1el Formation occur almost 

exclusively in the limestones. In general, their state of 

preservation is poor. They are found as internal and 

external molds and as crystalline calcite or silica. replacenlents. The replacement of shell by silica is 

coarse and commonly beekitic (pl. 4, fig. 12) , whereas 

the ealcite replacement is fine. Leaching of the shells 

and their preservation as internal or external molds is 

1nost eommon in the more gypsiferous limestones. Many 

of the shells show effects of transport. Some specimens 

exhibit rounded surfaces with sculpture eradicated; 

others are fragmentary with rounded edges. 

The best preserved of the snails are the neritac.eans 

such as Lyosmna., some of which even retain their color 

pattern (pl. 2, fig. 18). Because of their thick dense 

shell, nerita.eeans occur well preserved whereas most 

other gastropod shells have been leaehed out. Color 

patten1s of the neritaceans are more readily preserved 

because the pigment is distributed in the deeper shell 

layers, whereas 1nost gastropod color markings are confined to the surficial layers. 

Of speeial note in dealing with the neritaceans is the 

fact that the shell layers are differentia.Ily preserved. 

For example, the speeimens of the type lot of Lyosoma 

powelli White bear well-preserved details of sculpture, 

and one would assume that the shells are well preserved. 

The genus Lyosmna was therefore described as lacking 
MARINE JURASSIC GASTROPODS, CENTRAL AND SOUTHERN UTAH D7 

of the Carmel Formation 

not common (6-15 specimens); C, common (15-50 specimens); A, abundant (50+ specimens)] 

Localities-Continued 

18C 19A 19B 20 21 22 23 24 25 26A 26B 27 28 29 30 31A 31B 31 C 32 33 34A 34B 35 36 37 A 37B 38A 38B 39 40 41 42 

------ ------ ______ ------ ________ ------ ____ ------ ______ ------ ________________ ---- ------ ____ ------ NC R ---- ---- ---- ---- ---- ---- ------ ---- ---- ---- ----

------ ------ ------ ------ R ---- ------ ---- ------ ------ ------ ---- ---- ---- ---- ---- ------ ---- ------ ---- ------ ---- ---- ---- ---- ---- ---- ------ ---- ---- ---- ----

------ ____________ ------ ____ ---- ------ ---- R ------ R ---- ---- ---- ---- ---- ------ ---- ------ ---- ------ ---- ---- ---- ---- ---- ---- ------ ---- ---- ---- ---- ------ ______ R ------ ---- ____ ------ R R ------ NC __ ---- ________________ ------ ---- ------ ____ ------ ---- ---- ---- ---- ---- ---- ------ ---- R ---- ---- ------ ------ ______ ------ ________ ------ ____ R ------ ------ ____ ---- ____________ ------ ____ NC R ------ ---- ---- ---- ---- ---- ---- ------ ---- ---- ---- ---- ------ ------ ------ NC ---- R NC ____ ------ ------ R R ________________ ------ ____ ------ ---- ------ ---- ? ---- ---- --·- ---- ------ ? ---- ---- ---- ------ ------ ------ ------ ____ ---- ------ ____ R ------ __________ ---- ________ R __________ R __________ ---- ---- R ---- ---- ---- ------ ---- ---- ---- ----

------ ------ ------ ------ ---- ---- ------ ---- R ------ ------ ---- ---- ---- ---- ---- ------ ---- ------ ---- ------ ---- ---- ---- ---- ---- ---- ------ ---- ---- ---- ---- ------ ______ R ------ __________________ NC ------ ------ R ________________ ------ ____ ------ ____ NC R ---- R ---- R ____ ------ ---- ---- ---- ---- ------ ______ ------ ______________ ------ ____ ------ ------ ------ ____________________ ------ ____ ------ R ? ---- ---- ---- ---- R ____ ------ ? ---- ---- ----

====== ====== ====== ====== ==== ==== ====== ==== :::::: :::::: :::::: ==== ==== ==== :::: :::: :::::: :::: :::::: :::: _R ___ -R- :::: ==== ==== ==== :::= ::::=: ::=: :::: :::: :::: ______ A A ------ ____ ---- ------ A A NC NC ---- ---- R ________ ------ ____ ______ R ? ---- ---- ---- ---- ---- ---- ------ ---- ---- ---- ----

------ ------ ------ ------ ---- ---- ------ ---- ------ ------ c ---- ---- ---- ---- ---- ------ ---- ------ ---- ------ ---- ---- ---- ---- ---- ---- ------ ---- ---- ---- ---- ------ ------ NC ------ ________ ------ ____ ------ R ------ ---- ---- ---- ---- ____ ------ ____ ------ ---- ------ ---- ---- ---- ---- ---- ---- ------ ---- ---- ---- ---- R ------ ______ ------ ________ ------ ____ ------ ------ ______ ____ ____ ____ ____ ____ ______ ____ ______ R ______ ---- R ____ ---- R R NC ---- ---- R ---- ------ ------ ______ ------ ________ ------ ____ ------ ________________________________ NC ____________________________ ---- ---- R ____ C -~-- ---- ---- ----

------ ------ ------ ? ---- ---- ------ ---- ------ ------ ------ ---- ---- ---- ---- R ------ ---- ------ ---- ------ ---- ---- ---- ---- ---- ---- ------ ... ___ ---- ---- ----

------ ------ ------ ------ R ---- ------ ____ ? ------ ------ ________ ---- R R C A ------ R C R ______ ---- ---- ---- ---- ------ ---- ? 

------ ------ ------ ------ ---- ---- ------ ---- ------ ------ ------ ---- ____ ---- ---- ____ ------ ____ ------ ---- N ---- ____ ---- ---- R ---- ------ ---- R ---- ---· 

______ ------ ------ ------ ---- R ------ ____ ------ ------ ------ ---- R ____ ---- ____ ------ ---- ------ ---- R R ---- ---- ---- ---- ---- R ---- ---- ---- R 

__ ____ NC R ------ ________ ------ ____ NC R NC ---- ---- R ________ ------ ---- ------ R ------ ---- ---- ---- ---- ---- ---- ------ ---- ---- ---- ----

a strong inner lip septum. However, silicified specimens 

(pl. 2, fig. 1) in the collections here studied indicate that 

there is an inner lip septum. The only inference to be 

drawn is that this feature is composed of shell material 

considerably less stable than the remainder of the shell. 

Evidence of a high-energy environment at many of 

the localities yielding gastropods is obvious. Many 

shells are worn or broken. One exa1nple is well shown 

by the small slab from locality 4 figured on plate 2 (fig. 

24). This surface shows very poorly sorted sediment 

consisting o~ well-rounded silty calcareous pebbles as 

much as 7 mm in length; subrounded quartz, feldspar, 

and other pebbles as much as 5 mm in diameter; and a 

coarse sand fraction of rounded shell fragments and 

oolites. The only recognizable shells are the durable, 

thick-shelled nerite Lymwma enoda. Experiments in 

ball mills (Keith Chave, oral commun., 1963) have 

shown that shells of the N eritidae are among the most 

durable when subjected to mechanical wear. 

The most common occurrence of gastropods in quantity is exhibited by the hand specimens figured on plate 

5. All the snails are small and show gross size sorting, 

which may indicate winnowing action. Commonly 

these small (2-5 mm) shells show effects of abrasion, 

sculpture being virtually eradicated (pl. 5, fig. 2), but 

in other hand specimens the shells may be well preserved (pl. 5, fig. 3). On some blocks, crude orientation of shell axes appears to indicate current direction; 

but commonly, orientation is random. The blocks on 

plate 5 show gTeat concentrations of snails. More commonly, however, these snails occur scattered on the surface of oolitic limestone slabs and are intermixed with 

a hash of broken shell fragments dominated by oysters, 

Oarnptonectes, and crinoid columnals. 

The gastropods occurring in the finer grained limestones that compose most of the lower member are more 

diverse and larger than those in other kinds of matrix. 

In such limestones, gastropods are complete and occur 

as scattered individuals intermixed with well-preserved 

valves of pelecypods that sometimes are articulated. 

The general lack of evidence of transport reflects less 

agitated conditions, and the more diverse assemblage 

of in faunal and epifaunal species suggests a life 

assemblage. 

GEOGRAPHIC AND STRATIGRAPHIC DISTRIBUTION 

The Carmel gastropods mirror many of the distributional patterns of the more widespread and diverse 

pelecypods (Imlay, 1964). Like the pelecypods they 

are 1nost abundant and diversified (fig. 2 and table 1) 

in the middle area (fig. 1), a 40-mile-wide belt trending 

southwestward from the west side of the San Rafael 

Swell. The gastropods are very poorly represented 

both in diversity and number in the Arapien Shale of 

the western area. Likewise, only seven species (one 

questionable) occur in the nearer shore facies of the 

eastern area. 

The eastern area gastropod fa una is sparse and contains few forms that can definitely be assigned specifically. The numerous small gastropods ("winnowed 

fauna~') that are common at many localities in the middle area are entirely lacking, as are the large Tylostomalike naticids. Such sparsity is similar to that of the 

pelecypods, of which the eastern area has yielded only 
D8 CONTRIBUTIONS TO PALEONTOLOGY 

about one-quwrter of the number of species found in 

the middle area. Stratigraphically, however, the 

gastropods of the eastern area are virtually restricted 

to the lower part of the lower limy unit of the Carmel 

Forn1ation, whereas many of the pelecypod species 

either range through the unit or are to be found only 

in the middle part of the unit. 

In the middle area, by contrast, six categories of 

gastropods range through the entire lower limy unit 

(fig. 2), although the greater diversity of gastropods 

occurs in the lower part of the unit. 

Obviously, the shallow, perhaps littoral, conditions 

of the eastern nearer shore area, where interfingering 

red siltstones and generally sandier sediments were deposited, were not conducive to the development of a 

diversified fauna. This is substantiated by both the epifaunal pelecypod fauna and the presence of neritas and 

patelliform snails among the few gastropods present. 

All the gastropod species present in the Cannel Fornlation fauna are restricted elsewhere in the western 

interior region to beds of Bajocian to Callovian age. In 

general, their state of preservation is such that it 

renders them useless for stratigraphic purposes. As can 

be seen in figure '2, hm;vever, 0 ossnwnnea bnlayi occurs 

widely in Member B (of Bajocian age) of the Twin 

Creek Li1nestone, as well as in the Carmel Formation. 

Lyosmna powelli has a wider geographic range (see fig. 

2) but also has a greater stratigraphic range, as it 

occurs in rocks of Bajocian to early Callovian age. The 

small gastropod asse1nblage is well represented in Member B of the Twin Peak Limestone of Utah, but is less 

common elsewhere. 

Of all the gastropods, the Lyosoma species may prove 

to be of the greatest stratigraphic utility. Their shells 

were thick and, hence, are better preserved than most 

other gastropod shells; they were widespread, and they 

changed through time. For example, Lyosonw powelli 

is succeeded by an undescribed species (pl. 2, fig. 4) 

found in middle to upper Callovian rocks from Idaho 

to Wyoming and Montana. 

SURVEY OF JURASSIC GASTROPODS OF 

NORTH AMERICA 

No concentrated effort has been made to describe the 

gastropod faunas of North America. The number of 

described species is small; thus, although the Carmel 

Formation fauna is an impoverished one when compared with described European Jurassic faunas, it is by 

default the largest described Jurassic gastropod fa una 

in North America. The reasons for the small number 

of described species are the following: First, most previous descriptions ha,Te appeared as part of a study of the 

total fauna of a form.ation (Cragin, 1905) or as single 

or scattered descriptions (Frebold, 1957) ; secondly, 

most of the gastropods are commonly ill preserved when 

compared with the clams or cephalopods; thirdly, and 

perhaps most important, the gastropods are only locally 

abundant, are generally spatially restricted, and do not 

approach the stratigraphic utility of the Jurassic Ammonoidea. Thus, knowledge of the Jurassic gastropods 

of North America rests primarily on scanty and scattered records that may distort the understanding of 

both their abundance and taxonomic diversity. 

MEXICO 

:.Mention of gastropods in the Jurassic rocks of Mexico 

is sparse and usually indefinite. Burckhardt ( 1930, 

p. 12) noted unnamed gastropods in the Lias; but before the lower Oxfordian, in what he termed the "Calcaires a N erinees" of the State of Zacatecas, one does not 

find any notation that gastropods occur in any profusion. Cerithiid gastropods are also noted by Burckhardt (1930, p. 91) from the ICimmeridgian beds. 

Imlay (1940, p. 395) noted similar occurrences in northern Mexico in beds of similar age range and indicated 

that locally some units contain numerous small unidentified snails. 

A cursory examination of the Mexican Jurassic collections of the U.S. Geological Survey shows that this 

sparsity is not a result of lack of interest on the part 

of various authors but is due to actual rarity. Gastropods occur very rarely in these collections and the 

degree of diversity is small. Only the following forms, 

all from the Middle and Upper Jurassic, have been 

noted: 

Pleurotomaria sp. 

Naticid gastropods 

H m·pagodes sp. 

N erineids undet. 

The dominantly cephalopod-bearing shales (Imlay, 

1940, p. 398), obviously indicate an environment that 

was inhospitable to the development of a diversified 

gastropod fauna. It is, on the other hand, difficult to 

understand why gastropods are scarce in the Upper 

Jurassic near-shore deposits that contain a diverse 

pelecypod fauna (Imlay, 1940). Imlay (1940, p. 393) 

noted the similarity of the pelecypod fauna with that of 

the Malone Formation of Texas, which, however, does 

bear a moderately diverse gastropod fauna in addition 

to the pelecypod fauna. 

UNITED STATES (CONTERMINOUS) 

GULF COAST 

Imlay ( 1941, 1945) described Late Jurassic (Ox-
MARIN'E JURASSIC GASTROPODS, CENTRAL AND SOUTHERN UTAH D9 

fordian) gastropods recovered from cores in Alabama, 

Arkansas, Louisiana, and Texas. These consisted of: 

Superfamily Neritacea 

Family Neritidae 

N eritopsis? sp. 

Superfamily Cerithiacea 

Family Procerithiidae 

Xystrella? aff. X. papillosa (Deslongchamps) 

Ory,ptoptyaJ'is? tm-mosa Imlay 

Oryptoptymis? aff. 0. grimaldi (Guirand and Ogerien) 

Oryptoptyxis? diversicostata Imlay 

Superfamily N erineacea 

Family Itieriidae 

Phanet·optyxis angulata Imlay 

Family N erineidae 

Aptyxiella (Net·inoides?) aff. A. stantor~i (Cragin) 

Nerinea aff. N. goodelli Cragin 

N erinea aff. N. eudesii Morris and Lycett 

Ne1'inea cf. N. turbatrim de Loriol 

N erinella? sp. 

All the preceding come from the Smackover Formation which, on the basis of associated ammonites, Imlay 

considered to be of late Oxfordian age. These gastropods appear to have affinities with those of Europe. It 

is interesting to note that the gastropods of the Smackover are like those of the Carmel in abundance of small 

cerithiaceans. 

WEST TEXAS 

Cragin ( 1905) described a rather diversified shallowwater molluscan fauna frmn the Malone Formation 

(1\::immeridgian-Portlandian) of west Texas. The 

mollusks are assigned to 84 species, 56 of which are 

pelecypods. Compared with many other Jurassic 

pelecypod faunas, the Malone fauna contains a goodly 

representation of medium- to deep-burrowing forms. 

Compared with the gastropod fauna of the Carmel 

Formation, the gastropods of the Malone are similar 

in the ample representation of neritids and nerineids, 

but the number of cerithiaceans is relatively low. 

Gastropods from the Malone Formation include: 

Superfamily Pleurotomariacea 

Family Pleurotomariidae 

Pletwotomaria circumtrunca Cragin 

Superfamily Trochacea 

Family Turbinidae 

Turbo? beneclathmtus Cragin ( =Pu;rpurina ?) 

Superfamily Neritacea 

Family Neritidae 

N erita nodolirata Cragin ( = Trachynerita?) 

Nerita finlayensis Cragin 

N erUa peroblata Cragin 

Superfamily Amberleyacea 

Family N ododelphinulidae 

Delphinula stantoni Cragin ( =Metriomphal,us) 

Superfamily Pseudomelaniacea 

Family Pseudomelaniidae 

Pseudom.elania goodelli Cragin 

766-939 0-65-2 

Superfamily Cerithiacea 

Family Turritellidae 

Tttrritella burokhardti Cragin 

Family Vermetidae 

Vermetus cornejoi Castillo and Aguilera? (=Ohaetopoda?) 

Family Cerithiacea 

Oerithium arcuiferum Cragin 

Superfamily Naticacea 

Family Naticidae 

N atica williamsi Cragin ( = Globularia) 

N atica inflecta Cragin ( =Globularia) 

N atica finlayensis Cragin ( = Globularia) 

N atica bilabiata Cragin ( = Globularia) 

Superfamily Nerineacea 

Family Nerineidae 

Net·inea goodelli Cragin 

N erinea ci.rcumvoluta Cragin 

N erinella stantoni Cragin 

Superfamily Acteonacea 

Family Acteonidae 

Acteonino? maloniana Cragin 

WESTERN INTERIOR 

Few species have been described from this large area. 

Potentially, a thorough study of the Jurassic gastropods 

of the western interior would contribute more to the 

know ledge of North American Jurassic snail faunas 

than would a study of any other area,. As in other 

areas, the gastropod fauna at most localities shows little 

diversity, although a few species may locally occur in 

profusion. 

Early ·workers such as Meek and Hayden ( 1865), 

White (1876), and Stanton (1899) reported a few, primarily neritld, species from the Upper Jurassic sequences of the Black Hills and Yellowstone Park areas. 

A few additional species have appeared in the literature 

since that time. Aside from these, reports have boon 

limited to faunal lists and notations in measured sections or discussions of stratigraphy of local areas. 

Species described from the marine Jurassic of the 

western interior exclusive of Utah include: 

1899. Neritina wyomingensis Stanton. Montana (probably Piper Formation). 

1876. N eritina? powelli White (type species of Lyosoma White). 

Twin Creek Limestone, Utah. 

1906. N m·itoma? ( Oncochilu s) occidentalis Whitfield and Hovey. 

Sundance Formation, Wyoming. 

1874. Neritina phaseolaris White. Twin Greek Limestone, Utah. 

1933. Scalaria cf. S. liasinus (Quenstedt) Sandige. Sundance 

Formation, Montana. 

As can be readily seen from the list of described species, all but one belong in the Neritidae, a family well 

known for its hardy, strong shells. 

In addition to the preceding, numerous species of 

fresh-water Mollusca have been described from the 
DlO CONTRIBUTIONS TO PALEONTOLOGY 

Morrison Formation. They were comprehensively reviewed by Henderson ( 1935) and Yen ( 1952) and need 

no further discussion here. 

As in Utah (seep. D8), the majority of the Jurassic 

gastropods of the remainder of the western interior 

come fron1 Middle Jurassic rocks. The most prolific 

and perhaps diverse Jurassic fauna occurs in the Gypsurri Spring Formation of Wyoming and is a.s yet 

(1964) unstudied. 

The following lists consist of specimens gleaned from 

the large Jurassic collections of the U.S. Geological 

Survey. The identifications of most of these specimens 

can be viewed only as tentative and are meant to be 

only an indication of taxonomic diversity and geographic and stratigraphic range of the taxa. 

Twin Greek Limestone.-The Twin Creek Limestone 

throughout its extent in north-central Utah, southeastern Idaho, and western Wyoming contains a gastropod 

fauna that is very similar to that of the Carmel Forma.-

tion. Member B of the Twin Creek Limestone the . ' partial age equivalent of the lower limy unit of the 

Carmel Formation, contains the la.rgest and most simila.r 

gastropod fauna. Assemblages of smaH gastropods 

(for example, Rhabdocolpus) occur both in members 

Band F. Gastropods of the Twin Creek include: 

Member B 

Utah 

Teinostomopsis? sp. 

Lyosoma powelli White 

Lyosoma enoda Sohl 

Rhabdocolpus viriosus Sohl 

Pseudomelania? sp. 

Oylindrobullina? sp. 

Idaho 

Assemblage of small gastropods (preservation poor) 

Lyosoma powelli White 

Naticiform gastropods indet. 

Oossmannea imlayi Sohl 

Wyoming 

Assemblage of small gastropods (preservation poor) 

Lyosoma powelli White 

Naticiform gastropods indet. 

Oossmannea imlayi Sohl 

Oeritella cf. 0. tindonensis Huddleston 

Member 0 

Wyoming 

Naticiform gastropods indet. 

Member D 

·wyoming 

N erinea? sp. 

Member E 

Utah 

N erinea? sp. 

Naticiform gastropods indet. 

Wyoming 

Trochiform gastropods indet. 

Turriculate gastropods indet. 

Member F 

Wyoming 

Assemblage of small gastropods (preservation poor) 

Gypsum Spring Formation.-The Gypsum Spring 

Formation of northwestern Wyoming is the age equivalent of the lower parts of the Twin Creek and Carmel 

Formations, and a number of species of gastropods a.re 

common to these formations. However, some parts of 

the Gypsum Springs, such as the limestones one-half 

1nile south of Mill Creek, Fremont County, Wyo., contain a preponderance of dissimilar types of snails that 

are dissimilar to those in the lower parts of the Twin 

Creek and Carmel. The gastropods are preserved as 

internal and external molds in a gypsiferous limestone. 

Surface features on the external molds are well reproduced. Potentially, this unit might produce the most 

diversified 1nolluscan fauna of the Jurassic of the western interior. The pelecypods are more diverse than 

the gastropods, and Imlay ( 1964) noted a number of 

pelecypod species similar to those of the Carmel Formation. A cursory examination of the collections 

yielded the following gastropods (asterisk denotes 

speeies common to the Carmel Formation) : 

Leptomaria n. sp. 

Trochiform gastropods indet. 

Bttckmanina? sp. 

*Nododelphinula? sp. 

* Lyosoma powelli White 

* Lyosoma cf. L. enoda Sohl 

N eritina sp. (very small) 

Oonia sp. (small) 

Pseudomelania sp·. 

Oloughtonia cf. 0. pyramidata (Morris and Lycett) 

Procerithium n. sp. 

Turriculate gastropods indet. 

*Tylostoma? sp. 

N aticiform gastropods indet. 

Oossmannea n. sp. 

N erineids undet. 

A more thorough study of the Gypsum Spring fauna 

would undoubtedly bring other species to light. At the 

Mill Creek locality most species are small, only the nerineids and Oloughtonia being of medium size. Most 

abundant are the sn1all procerithids, which are usually 

only a few millimeters long. 

"Lower Sundance Formation."-The "Lower Sundance Formation" (mid-Bajocian to Callovian) of central and southeastern Wyoming is also a partial age 

equivalent of the Carmel Formation and bears a gastropod fauna similar to that of the Carmel, both formations having almost all represented genera in common 

as well as having a number of identical species. Tylostoma ~ sp. and small indeterminate naticiform gastropods preserved as molds are perhaps the most 
MARINE JURASSIC GASTROPODS, CEINTRAL AND SOUTHERN UTAH Dll 

abundant; hut Lyosoma powelli White is known from 

four localities. The following gastropods occur in the 

"Lower Sundance Formation" (an asterisk denotes 

species common to the Carmel Formation) : 

Pleurotomaria sp. 

* Lyosoma powelli White 

* Lyosoma enoda Sohl 

N eritina? sp. 

*Nododelphinula? sp. 

Purpurina cf. P. canceUata Huddleston 

Pseudomelania sp. 

*Tylostoma? sp. 

NaUciform gastropods indet. 

Oeritella? sp. 

Oossmannea sp. 

Oylindrobullina? sp. 

Canyon Springs Sandstone Member of the Sundance 

Formation.-The Canyon Spring Sandstone Member 

(lower Callovian) of the Sundance Formation of 

northeastern Wyoming and western South Dakota 

bea-rs a gastropod fauna distinctive primarily for its 

numerous internal molds of naticiform gastropods. In 

addition, the member marks the upper limit for the 

range of Lyosoma powdli and perhaps L. enoda. The 

few species present, which are similar to those of the 

Carmel Formation, are given in the following list: 

Lyosoma powelli White 

Lyosoma cf. L. enoda Sohl 

Tylostoma? sp. 

Naticiform gastropods indet. 

Piper Formation.-The Piper Formation (BajocianBathonian) of eastern Montana is the approximate age 

equivalent of the lower limy unit of the Carmel Formation, but the few gastropods collected from it have little 

relationship to those of the Carmel except at the generic 

level. The gastropods of the Piper include: 

N eritina cf. N. wyomingensis Stanton 

Pseudomelania sp. 

Procerithium? sp. 

Exelissia? sp. 

Naticiform gastropods indet. 

Oossmannea? sp. 

Sawtooth Forrnation.-The Piper Formation g-rades 

westward in Montana to the Sawtooth Formation 

(Bajocian-Bathonian). Both the Piper and the Sawtooth have yielded only a few gastropods that have little diversity and little other than generic similarity to 

the gastropods of the Carmel Formation. The Sawtooth has yielded the following gastropods : 

Pseudomelania sp. 

Rhabdocolpus sp. 

N atidform gastropods indet. 

Co:~smannea? sp. 

Preuss Sand8tone,.-The Wolverine Canyon Limestone Member (Callovian) of the Preuss Sandstone 

(Imlay, 1952) in southeastern Idaho is slightly younger 

than the Carmel Formation. It locally bears the following silicified gastropods : 

Lyosoma cf. L. powelli Whiten. sp. 

Emelissia n. sp. 

Procerithium n. sp. 

Naticiform gastropods indet. 

Oossmannea n. sp. 

The Lyosom.a noted in the preceding list also occurs 

in the Hulett Sandstone Member of the Sundance Formation in the Black Hills area and in the Rierdon Formation of Montana, both of Callovian age. None of 

these species occur in the Carmel Formation of Utah. 

Hulett Sandstone Member of the Sundance Forrmat,ion.-The Hulett Sandstone Member (Callovian) of 

the Sundance Formation has yielded a Lyosoma at one 

locality in Fremont County, Wyo. (USGS 22078). 

This Lyosoma is of the L. powelli type but possesses 

thin, fine incrementals typical of the shell from the 

Rierdon shown on plate 2, figure 4. The same species 

also occurs in the slightly younger Wolverine Canyon 

Lim.estone Member of the Preuss Formation and may 

serve well as a Callovian marker in Idaho, Wyoming, 

and Montana. 

Rierdon Formation.-The Rierdon Formation (lower 

Callovian) is a widespread marine unit in Montana. 

The most comm~n gastropods are small internal molds 

of naticid forms, but all identified genera are common 

to other units of the western interior Jurassic. Most 

significant is Lyosoma cf. L. powelli (pl. 2, fig. 5), which 

is also present in the Hulett Sandstone Member of the 

Sundance Formation in the Black Hills area and in 

theW olverine Canyon Limestone Member of the Preuss 

Sandstone. The following gastropods were collected 

from the Rierdon: 

Pleurotomaria sp. 

Lyosoma cf. L. powelli White (n. sp.) 

Rhabdocolpus sp. 

Tylostoma? sp. 

Naticiform gastropods indet. 

Oossmannea sp. 

Swift Formation.-The Swift Formation (Oxfordian) of Montana is the youngest Jurassic marine unit of 

the western interior for which we have records of gastropods. The most unusual form is one that may belong 

to Dicroloma and represents the only record of the family Aporrhaidae in the Jurassic of the western interior. 

The gastropods of the Swift include: 

Lyosoma cf. L. enoda Sohl ( n. sp.) 

cf. Dicroloma sp. 

Pleurotomaria sp. 
D12 CONTRIBUTIONS TO PALEONTOLOGY 

PACIFIC COAST 

The Jurassic sequence of the Pacific coast has yielded 

but seven described gastropod species. These are : 

Turbo paskentaensis Stanton ( =Oolitioia) 

Trochus hinchrnanensis Orickmay 

Arnberleya dilleri Stanton 

Oerithiu.n~J paskentaensis Stanton ( =Paracerithium ?) 

Hyp~ipleura? ocoidentalis Stanton ( =Paracerithium) 

N er1.nea thompsonensis Crickmay 

Itierla californica Anderson 

Stanton's and Anderson's species all come from the 

latest Jurassic beds (Portlandian) in the Coast Range 

and show their closest affinities to the species of Alaska. 

Crickmay's species are from beds of Bajocian age from 

the T~yl~rsville area in the Sierra Nevada. A cursory 

e~aminatwn of the U.S. Geological Survey collections 

yielded no additional identifiable gastropods. 

CANADA 

The Jurassic faunas of Canada have been the subject 

of studies primarily by Frebold, Warren, Crickmay, 

McLearn, and others. Although many ammonites and 

pelecypods have been described in these works few 

?astropods have been noted. Persbnal field expe~ience In the Canadian Rockies indicates that this scarcity of 

s~ails is not the result of neglect but of poor representatiOn ?f gastropods. They are not diverse at any known 

locality nor are they widespread. 

~long ~he Canadian Rockies, the Nordegg Member 

(Sinemurian) of the Fernie Shale in the Cadomin area 

contains numerous large specimens of an undescribed 

f!leurotmn~ria that are especially noteworthy. Higher 

Ill the Fernie sequence, in black shales of the Rock Creek 

Member (Bajocian) in the vicinity of Blairmore, Dr. 

Hans Frebold of the Canadian Geological Survey has 

collected numerous specimens of a potamidid snail. 

Better known, however, is "Twrbo" fernien.sis Frebold 

which occurs at many localities throughout Alberta i~ the upper Oxfordian "Green Beds" of the Fernie Shale 

(Frebold, 1957, p. 58). This species is one of the few 

Jurassic gastropod species to have a demonstrated 

stratigraphic utility in North America. The "Grey 

Beds" (Callovian to Oxfordian) of the Fernie contain a. 

few poorly preserved gastropods assignable to such 

common Jurassic genera as Pleurotomaria and Amberleya. 

British Columbia has also yielded records of a few 

gastropods. Pfeurotomaria skidegaten.si.s Whitea.ves occurs in the Yakoun Formation of Queen Charlotte Is~ 

land. Crickmay ( 1930) found Pseudomelarnia in the 

Opuntia Formation (Bajocian) of the Ashcroft area. 

Frebold (1959, p. 11) noted the presence in this area of 

additional undetermined Sinemurian gastropods. 

Frebold ( 1960, p. 4), in speaking of the Jurassic of 

the Akla vik Range in the Canadian Arctic, stated : "The 

Lower Jurassic faunas in this area consist mainly of 

ammonites, nautiloids, pelecypods and gastropods, of 

which the ammonites form the most important part." 

Unfortunately the affinities of these gastropods are 

unknown. 

ALASKA 

The Alaskan Jurassic sequence may contain a greater 

diversity of gastropods than any other area on the 

North American continent. Some of the fauna, primarily the cephalopods, was described by Imlay (1953, 

1962). The difficulty of collecting and transporting 

large samples from Alaska limits the basis for evaluating the relative abundance of gastropods. The following notations serve only as an indication of th~ 

presence of taxonomic groups. Obviously, intensive 

collecting would increase the list considerably. 

It should be noted, however, that the greatest diversity of gastropods in Alaska. occurs in the Kialagvik 

Formation and the Tuxedni Group of Bajocian to 

Bathonian age. This observation correlates well with 

similar times of ma.ximum diversity of gastropods in 

the western interior of the United States. 

The Early and Middle Jurassic Alaskan gastropods 

have close affinities with European species groups. The 

Late Jurassic forms appear dissimilar, but this conclusion is subject to reservations because of lack of diversity among the gastropods, scarcity of specimens, and 

vagaries of preservation. 

The gastropods that occur in Alaska a.re given in 

the following list: 

Talkeetna Formation (Lower Jurassic) 

Pleurotornar·ia cf. P. subarenosa Huddleston 

Pleurotomaria sp. 

Arnberleya cf. A. densinodosa Huddleston 

Oonia cf. Oonia subglobosa (Morris and Lycett) 

Oloughtonia sp. 

Procerithium cf. P. vetu.stum (Phillips) 

Kialagvik Formation (Bajocian) 

Pleurotornar·ia cf. P. subarenosa Huddleston 

Pleu,rotornaria sp. A 

Pleurotornaria sp. B 

M onodonta n. sp. 

Purpurina cf. P. elaborata Morris and Lycett 

Put·pur·ina sp. 

Pseudornelania cf. P. ( Oonia) leyrneriei ( d'Archiac) 

Pseudornelania cf. P. ( Oonia) subglobosa (Morris and Lycett) 

Tuxedni Group (Bajocian to Bathonian) 

Pleurotornaria sp. A 

"AI ar·garites" sp. 

Arnbet·leya cf. A. densinodosa Huddleston 

Arnberleya cf. A. ornata J. Sowerby 

Arnberleya sp. indet. 

Metriornphalus cf. M. harnptonensis (Morris and Lycett) 
MARINE JURASSIC GASTROPODS, CENTRAL AND SOUTHERN UTAH Dl3 

Tuxedni Group (Bajocian to Bathonian)-Continued 

"Turbo" cf. "T." subpyramidalis d'Orbigny 

Purpurina cf. P. hellona d'Orbigny 

Pseudomelania cf. P. ( Oonia) leyme1·iei ( d' Archiac) 

Procerithium cf. P. michinhamptonense Cox and Arkell 

Procerithium? sp. 

Oloughtonia cf. C. pyramidata Morris and Lycett 

N erinea? sp. 

Cylindrobullina? sp. 

Tornatellaea cf. T. sedgvici (Phillips) 

Chinitna Formation (Callovian) 

Amberleya cf. A. delia ( d'Orbigny) 

Amberleya? sp. 

Procerithium? sp. 

Tornatellaea cf. T. sedgvici (Phillips) 

Shelikof Formation (Callovian) 

Amberleya cf. A. delia (d'Orbigny) 

Amberleya sp. indet. 

Lower part of Naknek Formation (Oxfordian) 

Amberleya cf. A. delia ( d'Orbigny) 

Upper part of Naknek Formation (Kimmeridgian) 

"Margarites" sp. 

Amberleya cf. A. delia (d'Orbigny) 

Amberleya sp. 

The Alaskan species cited in the preceding list contrast very strongly with those of the Carmel Formation. 

No gastropod species and few genera are common to the 

two areas. The gastropod fauna of the Carmel Formation is dominated by neritid and naticid forms, whereas 

the Alaskan faunas are more diversified taxonomically. 

N eritids that are co·mmon in the Carmel fauna are absent fron1 the Alaskan faunas; nerineids, rather common in Utah, are poorly represented to the north, as are 

naticid gastropods. Members of the Amberleyacea are 

present in both areas but are ra.re in the western interior 

and common in Alaska. Thus, the gastropods of these 

areas contrast not only in taxonomic representation but 

also in abundance of common genera; similar differences may be seen in the cephalopods (Imlay, 1953; 

1962). 

Aside from geogra.phic separation, depth of water 

and salinity most likely account for, or contribute to, 

the contrast between the faunas. The Alaskan faunas 

indicate, in general, a deep-water, open, normal-marine 

environment. Imlay (1953, p. 57-65) cited the lack of 

littoral mollusks in the Alaskan Callovian sequence. In 

contrast, both physical and faunal evidence point to a 

littoral environment prevailing in many areas of the 

western interior. The rarity of nerineid gastropods 

in Alaska supports Imlay's suggestion that northern 

waters were cooler. 

SUMMARY 

1. The Jurassic gastropod faunas of North America 

have little interregional continuity. This provinciality 

is well displayed by the lack of common species. There 

is some silnilarity between the gulf coast, west Texas, 

and Mexico faunas, but there is a distinct separa.tion 

between these and the western interior faunas. The 

Alaskan gastropod faunas appear to be distinct from 

all of these. 

2. In the gastropod faunas of the gulf coast and west 

Texas areas, diversity is greatest in beds of Late Jurassic age, whereas in the western interior and Alaska, 

diversity is greatest in units of Bathonian and Bajocian 

~age. 

3. Shallow near-shore, perhaps littoral gastropod~., 

such as the N eritidae, are most common in Texas and 

the western interior but become less common northward 

to Alaska. The same holds true for the Nerineacea and 

N aticacea. The lesser numbers of N erineacea suggest 

cooler water to the north. 

4. The total fauna is taxonomically typical of the 

Jurassic with strong representation of the N eritacea, 

Amberleyacea, Pseudomelaniacea, Cerithiacea, and 

N erineacea. No Neogastropoda are present, and representation of the Euthyneura is poor except for the 

N erineacea. 

5. Total fauna is shallow water in origin, but the 

Alaskan fauna may represent a deeper water environInent than that of the western interior and west Texas. 

Marine Gastropoda of the Jurassic of North America 

[Letters indicate stratigraphic range: S, Sinemurian; Pl, Pliensbachian ; Ba, Bajocian ; Bt, Bathonian ; C, Callovian ; 0, Oxfordian ; 

K, Kimmeridgian P, Portlandian. Numbers indicate geographic 

range ; 1, Mexico ; 2, Gulf coast and Texas ; 3, Western interior; 4, 

Canada; 5, Alaska; 6, Pacific coast] 

Subclass Streptoneura 

Order Archaeogastropoda 

Superfamily Pleurotomariacea 

Family Pleurotomariidae 

Pleurotomaria circumtrunca Cragin (K-P) (2) 

Pleurotomaria? borealis Warren ( Ba) ( 4) 

Pleurotomaria skidegatensis Whiteaves (Ba-Bt) ( 4) 

Pleurotomaria cf. P. subarenosa Huddleston (Pl, Ba) 

(5) 

Pleurotomaria spp. (Pl-0) (3-5) 

Leptomaria n. sp. (Ba) (3) 

Superfamily Patellacea 

Family Symmetrocapulidae 

Symmetrocapul~ts? corrugatus Sohl (Ba-Bt) (3) 

Superfamily Trochacea 

Family Trochidae 

"T1·ochus" hinchmanensis Orickmay (Ba) (6) 

B uckmanina? sp. ( Ba) ( 3) 

M onodonta n. sp. ( Ba) ( 5) 

"Margarites" sp. (Ba, Bt, K) (5) 

Family Skeneidae 

Teinostomopsis? sp. (Ba, Bt) (3) 

Family Turbinidae 

Turbo? beneclathratus Cragin ( =Purpurina) (K, P) 

(2) 

"Turbo" subpyramidalis (d'Orbigny) (Ba, Bt) ('5) 
D14 CONTRIBUTIONS TO PALEONTOLOGY 

~JJlarine Gastropoda of the Jurassic of North America-Continued 

Subclass Streptoneura-Oontinued 

Order Archaeogastropoda-Continued 

Superfamily Neritacea 

. Family N eritopsidae 

Neritopsis? sp. (0) (2) 

Family Neritidae 

Trachynerita? nodolirata Cragin (K, P) (2) 

Nerita? finlayensis Cragin (K, P) (2) 

Nerita'l peroblata Cragin (K, P) (2) 

Lyosoma pmvelli White (Ba-Lower C) (3) 

Lyosoma aff. h. powelli White n. sp. (C) (3) 

Lyosoma enoda Sohl (Ba, Lower C) (3) 

Lyosoma cf. L. enoda Sohl ( 0) ( 3) 

Neritina phaseolaris White (Ba, Bt) (3) 

Neritina wyomingensis Stanton (Ba, Bt) (3) 

Neritina sp. (Ba-Bt) (3) 

Otostoma? occidentalis (Whitfield and Hovey) (Bt) 

(3) 

Superfamily Amberleyacea 

Family Amherleyidae 

Amberleya dilleri Stanton (P) (6) 

Amberleya cf. A. delia ( d'Orbigny) ( 0-K) ( 5) 

Amberleya cf. A. ornata Sowerby (Ba, Bt) (5) 

Amberleya cf. A. densinodosa Huddleston (Pl, Ba-Bt) 

(5) 

Amberleya sp. (Ba-K) (3, 5) 

Ooliticia paskentaensis ('Stanton) (P) (6) 

Oolitwia? ternieensis (Frebold) (0) (4) 

Ooliticia? sp. ( Ba, Bt) ( 3) 

Family N ododelphinulidae 

Metriomphalus stantoni (Cragin) (K, P) (2) 

Metrimnphalus cf. M. hamptonensis (Morris and 

Lycebt) (Ba-Bt) (5) 

Nododelphinula? sp. (Ba, Bt) (3) 

Order Mesogastropoda 

Superfamily Littorinacea 

Family Purpurinidae 

Purpurina cf. P. ca.ncellata Huddleston (Ba-Bt) (5) 

Purpurina cf. P. elaboratus Morris and Lycett (Ba) (5) 

Purpurina cf. P. hellona d'O~bigny ( Ba) ( 5) 

Purpurina sp. ( Ba) ( 5) 

Superfamily Pseudomelani'acea 

Family Pseudomelaniidae 

Pseudomclania goodelli Cragin (K--<P) (2) 

Pseudomelania sp. (Ba-Bt) (3, 4) 

P seudomelania ? sp. ( Ba) ( 3) 

Oonia cf. 0. subglobosa (Morris and Lycett) (Pl, Ba) 

(5) 

Oonia cf. 0. leymeriei (d'Archiac) (Ba-Bt) (5) 

Oonia sp. (Ba-Bt) (3) 

Oloughtonia cf. 0. pyramidata (Morris and Lycett) 

(Ba) (3) 

Oloughtonia sp. (Pl) (5} 

Superfamily Cerithiacea 

Family Turritellidae 

TurrUella? burckha~rdtiOragin (P-K) (2) 

Family Procerithiidae 

X ystrella n. sp. ( Ba) ( 3) 

Xystrella? aff. X. papiUosa (Deslongchamps) (0) (2) 

Oryptoptya:is? formosa Imlay ( 0) (2) 

Orypto,ptyaJis? aff. 0. grimaldi ·(Guirand and Ogerian) 

(0) (2) 

Marine Gastropoda of the Jurassic of North America-Continued 

Subclass Streptoneura-Continued 

Order Mesogastropoda-Continued 

Superfamily Cerithiacea-Continued 

Family Procerithiidae--Oontinued 

Oryptoptymis? diversicostata Imlay ( 0) (2) 

Rhabdocolpus viriosus Sohl (Ba-Bt) (3) 

Rhabdocolpus sp. (Ba-Lower C) (3) 

Procerithiu,m n. sp. (Ba) (3) 

Procerithium cf. P. vetustum (Phillips) (Pl) (5) 

Procerithium cf. P. michinhampotnense Cox and 

Arkell (Ba-Bt) (5) 

Procerithiwm?spp. (Ba-0) (3,5) 

Paracerithium ocoidentalis (Stanton) (P) (6) 

Paracerithium? paskentaensis (Stanton) (Ba-Bt) (6) 

Emelissia n. sp. (C) (3) 

Emelissia? sp. (Ba-Bt) (3) 

Family Cerithiidae 

06'rithium arettiferum Cragin (P-K) (2) 

Superfamily Strombacea 

Family Aporrhaidae 

Harp·a.godes (Ba-P) (1) 

cf. Dicrolorna sp. (0) (3) 

Superfamily Naticacea 

Family Naticidae 

Globttlaria williamsi Cragin (P-K) (2) 

OZobula1·ia inflecta Cragin (P-K) (2) 

Globnlaria finlayensis Cragin (P-K) (2) 

Globularia bilabiata Cragin (P-K) (2) 

Globularia sp. (Ba-Bt) (3) 

Tylostoma? sp. (Ba-Lower C) (3) 

Naticids indet. (Ba-C) (3) 

Subclass Euthyneura 

Order Entomotaeniata 

Superfamily N erineacea 

Family Oeritellidae 

Oeritella cf. 0. tindonensis Huddleston (Ba-Bt) (3) 

Family N erineidae 

Aptymiella (Endiatrachelus) goodelli (Cragin (K-P) 

(2) 

Aptymiella circumvoluta Cragin (K-P) (2) 

Nerinea aft. N. goodeUi (Cragin) Imlay (0) (2) 

N erinea aff. N. eudesii Morris and Lycett ( 0) ( 2) 

N erinea cf. N. turbatrim (de Lorio I) ( 0) ( 2) 

N erinea? t hompsonensis Crickmay ( Ba) ( 6) 

Nerinea'l sp. (Ba-Bt) (3, 5) 

Nerinoides? stantoni Cragin (K-P) (2) 

N erinoides? sp. ( 0) (2) 

Nerinoides'l aff. A. stantoni Imlay (0) (2) 

Oossmannea im,layi Sohl (Ba-Bt) (3) 

Oossmannea? kanabensis Sohl (Ba-Bt) (3) 

Oossmannea n. sp. (Ba-C) (3) 

0 ossmannea? spp. ( Ba Lower C) ( 3) 

Indeterminate nerineids (Ba-P) (1, 3) 

Family Itieriidae 

Phaneroptymis angulata Imlay (0) (2) 

Itieria californica Anderson (P) (6) 

Order Cephalaspidea 

Superfamily Acteonacea 

Family Acteonidae 

Acteonina,? maloniana Cragin (K-P) (2) 

Tornatellaea cf. T. sedgvioi (Phillips) (Ba-G) (5) 

Oylindrobullina? sp. (Ba-Bt) (3, 5) 
MARINE JURASSIC GASTROPODS, CENTRAL AND SOUTHERN UTAH D15 

SYSTEMATIC PALEONTOLOGY 

The usage and sequence of treatment of the higher 

taxonomic categories follows the classification of Taylor 

and Sohl ( 1962). Morphologic terminology conforms 

to that used in the "Treatise on Invertebrate Paleontology" by Knight and others (1960, p. 1129-1135.) 

Under the heading "Types" the abbreviation USNM 

indicates that the specimen is deposited in the type collections of the U.S. National Museum. Numbers listed 

in the sections headed "Occurrence" refer to localities 

described on pages D3-D4 and diagran1ma.tically 

located in figure 1. Numbers prefaced by USGS refer 

to collection numbers recorded in the U.S. Geological 

Survey Mesozoic locality register. 

Class GASTROPODA Cuvier, 1797 

Subclass STREPTONEURA Spengel, 1881 

Order ARCHAEOGASTROPODA Thiele, 1925 

Superfamily PLEUROTOMARIACEA Swainson, 1840 

Family PLEUROTOMARliDAE Swainson, 1840 

Genus PLEUROTOMARIA Defrance, 1826 

Type by subsequent designation (S. P. Woodward, 

1851), Trochus anglicus J. Sowerby, 1818. 

Discussion.-Pleurotomarians are common in the 

Jurassic faunas of many areas. In the Jurassic of 

North America four species have been described. For 

the most part they are based on poor material, but representatives are to be found from west Texas to Alaska 

in beds of Bathonian to Portlandian age. 

Pleurotomaria ~ sp. 

Plate 1, figures 9, 13 

Discussion.-Several poorly preserved internal molds 

from the Carmel Formation at localities 33 and 34A 

are questionably assigned to Pleurotomaria on the basis 

of gross shape. 

The molds are of medium size, trochiform, and 

broadly umbilicate (pl. 1, fig. 9), but no distinct selenizone can be discerned. The whorls are biangulate (pl. 

1, fig. 13). The upper whorl angulation separates the 

Inoderately broad, subsutral ramp above from the flat 

outer-whorl faee, whereas the second angulation delimits the rounded base. One mold retains the faint 

impression of fine widely spaced spiral lirae on the 

base. 

I have found record of only four described species of 

Pleurotonwria from the Jurassic of North America. 

P. skidegaten.sis 'Vhiteaves, Yakoun Formation, Vancouver, B.C. 

P. circumtrun.ca Cragin, Malone Formation, Texas. 

P.? bm·ealis Warren, Fernie shale, Canada. 

P. cf. P. rozete (de Loriol) Spath, Portlandian, East Greenland. 

None of these species are well preserved, and none 

retain sufficient character for confident placement. 

The molds from Utah are similar to Plewrotomaria~ 

borealis Warren ( 1932, p. 33) in gross form, but beeause 

of poor preservation no close comparison ean be made. 

Warren's speeies is evidently from the Rock Creek 

Member (Bajocian) of the Fernie shale and of approximately the same age as the Carmel species. 

Type: Figured s~cimen USNM 144826. 

Occurrence: Utah : Carmel Formation at loc. 33, 34A. 

Superfamily PATELLACEA Rafinesque, 1815 

Family SYMMETRO,CAPULIDAE, Wenz, 1938 

Genus SYMMETROCAPULUS Dacque, 1933 

Type by original designation, Patella rugosa J. Sowerby, 1816. 

Symmetrocapulus ~ corrugatus Sohl, new species 

Plate 1, figures 22-24 

Diagnosis.-Medium-sizecl patelliform shell bearing 

coarse concentric folds and having the apex situated at 

anterior third quarter of length. 

Descri.ption.-Shell medium size, patelliform, rather 

high and moderately thiek; apex situated at about anterior third quarter of length. Protoeonch unknown. 

Anterior slope moderately steep and somewhat concave; 

posterior slope less steep and roundly convex. Sculpture consisting of coarse concentric growth rugae most 

closely spaced below the beak and usually coarsening at 

later growth stages. Aperture ovate, muscle scars unknown, interior of shell crenulate in harmony with the 

coarse concentric corrugations of the exterior. 

Measurements.-The holotype measures 32.7 mm in 

length, 24 mm in diameter, and 13.2 mm in height. 

Discussion.-! was unable to find any record of described species of patelliform gastropods from the J urassic of North America. Preliminary examinations of 

the Geological Survey Jurassic collections from the 

western interior yielded no speeimens assignable to the 

Patellacea. In addition, there appear to be no closely 

similar species from Europe. The type species Symmet,rocapulus rugosa J. Sowerby is proportionally lower 

and has distinctive radial sculpture that is absent on the 

species from the Carmel Formation. 

Placement of this species in Symm.etrocapulus IS 

questioned as the internal musculature is unknown. 

Types: Holotype USNM 144827. 

Occurrence: Utah: Carmel Formation at loc. 21. 

Superfamily TRO·CHACEA Rafinesque, 1815 

Family CYCLOSTREIYIATIDAE Fischer, 1885 

Genus TEINOSTOMOPSIS Chavan, 1954 

Type by original designation, T einostomopsU5 saharae 

Ohavan. 

Teinostomopsis ~ sp. 

Plate 1, figures 2-4, 7 
D16 CONTRIBUTIONS TO PALEONTOLOGY 

Disaussion.-Smooth-surfaced rotelliform shells, usually not exceeding 2 mm in diameter, occur weathered 

out on limestone slabs at several localities. Most specimens show only the low spire and its slightly convex 

whorls. I was able to excavate one specimen (pl. 1, 

fig. 3) that has the aperture partly weathered out. The 

base of the shell is anomphalus, but slightly depressed 

over the umbilical region. A callus pad covers much of 

the base. The pad edge can be only faintly seen extending frmn the umbilical area to the base of the inner lip. 

The inner lip is strongly curved and be,ars a broad callus 

tooth that partially infringes the aperture low on the 

inner lip but extends onto the parietal surface. The 

outer lip is highly inclined and appears to thin toward 

the edge. 

In shape and in the apertural features that can be 

seen, these little shells n1ost closely resemble Teinostonwpsis, but the sutural characterisi:ics and the placement of the inner lip callus differ somewhat. Better 

preserved specimens are necessary before placement is 

certain. 

Types: Figured specimens USNM 144829--144831. 

Occurrence: Utah: Carmel Formation at locs. 25, 26B; Twin 

Creek Limestone (member B) at loc. USGS 28458, near Thistle. 

Utah County. 

Trochacea 1 sp. 

Plate 1, figures 1, 6, 8 

Discu.S'sion.-Small trochiform snails occur at several 

localities in the Cannel Fonnation. The shells generally do not exceed 2 111111 in height and 4 mm in diameter. 

They consist of 3-4 whorls of circular cross section 

having an unon1amented surface, except for fine rather 

highly inclined prosocline growth lines. The base and 

apertural features are unknown. The shells appear to 

represent only one species, but preservation is so poor 

that only the broadest assigmnent can be made. 

Similar trochids also occur in the Twin Creek Limestone of the Crab Creek section near Thistle, Utah. 

Types: Figured specimens USNM 144828, 144832, 144833. 

Occurrence: Utah: Carmel Formation at locs. 7A, 8, 19B, 24, 

25, 26B. 

Superfamily NERITACEA Ra:finesque, 1815 

Family NERITIDAE Ra:finesque, 1815 

Subfamily NERITININAE Rafinesque, 1815 

Genus LYOSOMA White, 1883 

Type by subsequent designation (Fischer, 1885, p. 

801), N eritina po1oelli White, 1876. 

Diagnosis-The original diagnosis by White ( 1883, 

p. 152) was as follows : 

Shell resembling certain forms of N eritina and N erita in general aspect; volutions few, the last one much expanded; outer 

lip moderately thin; inner lip not thickened and apparently 

without any callus; the portion of the body exclusive of the last 

volution, very small and without a proper columella. Both of 

the only two species yet known have a slight flattening or 

lessening of the convexity of both the upper and outer sides 

of the last volution; the upper side having a more or less distinct but shallow revolving depression along its middle portion. 

This diagnosis must be amended to state: inner lip 

thickened, aperture constricted by a -rather straight 

nondentate inclined septum that is continuous with 

thickening of outer lip. 

Dismtssion.-Binkhorst ( 1873) noted that the inner 

lip callus and septum are lost in some species of fossil 

neritaceans. White (1883, p. 153) was aware of this, 

but he was convinced that the material upon which he 

based his genus Lyosoma was sufficiently well preserved 

to show a septum had it been present. Although the 

genus Otostoma d'Archiac was originally described as 

a nonseptate form, Fischer (1885, p. 801) found impressions of an inner lip septum on internal molds assigned 

to this genus. For this reason Fischer thought the two 

genera Otostoma and Lyosoma might be synonyms. 

Cossmann (1925, p. 205), however, retained Lyosoma as 

a separate section under Des1nieria Douville, an objective synonym of Otostoma. Wenz (1938, p. 418) later 

considered Lyosoma a subgenus of Otostoma, but more 

recently, Keen and Cox (in Knight and others, 1960, 

p. I285) again assigned Lyosoma as a questionable 

synonym of Otostoma. 

More than 80 specimens of Lyosoma powelli from 

various localities in Utah, Wyoming, and Montana are 

present in the U.S. Geological Survey collections. An 

inner lip septum is present on only two of these. One 

specimen (USNM 144834) from 1Vyoming, retaining 

a strong median septum is silicified ; the other specimen 

is preserved as a crystalline calcite shell. The reason 

for loss of the septum on the other seemingly wellpreserved specimens cannot definitely be determined. 

The callus is deposited by a different part of the mantle 

than the part that forms the rest of the shell. I suggest, therefore, that the composition of these two parts 

of the shell may be mineralogically variable and subject 

to differential solution. 

Inclusion of Lyosorna in Otostoma is untenable. 

0 tostoma possesses denticles on the inner lip septum 

and lacks the carinate whorl of Lyosoma. Lissochilus 

Zittel, on the other hand, is similar in shape to Lyosoma 

and ha.s a nondentate septum but differs in having a 

higher spire, well-developed transverse sculpture, and a 

bicarinate periphery. 

White ( 1883, p. 153) proposed Lyosoma to include 

two species, N eritina? phaseolaris White and N eritina? 

powel~i, but did not designate a. type species. Fischer 
MARINE JURASSIC GASTROPODS, CE!NTRAL AND SOUTHERN UTAH D17 

(1885, p. 801) was the first subsequent author to mention a type species. The only subsequent list of included 

species was that provided by Cossma1m ( 1925, p. 206), 

but no mention of N. phaseolaris was made by him. As 

is discussed herein, under Lyosoma enoda, White's cotype lot (USNM 118587) contains specimens of two 

different species, N eritina phaseolaris and Lyosoma 

enoda. 

Cossmann's ( 1925, p. 206) list of species included in 

Lyosmna contains: N eritina capduri C'ossmann, from 

the Barremian of France; S tomatia ornatissima Coquand, from the Aptian of Spain; Stomatia bicarinata 

Guererra, from the Cenomanian of France; Li,ssochilu,s 

bena.hensis Bohm (1900, p. 193), from the Turonian of 

Lebanon; and Lyosoma squamosun& White ( 1888, p. 

179), from the Senonian of Brazil. On the basis of 

available material it is difficult to say whether any of 

these species belong in Lyosoma. As an example, Lyosmna squmnosum White fits well within the genus in 

most features, but the one available specimen, the holotype, lacks a 1nedian septum. One cannot be sure 

whether, like the holotype of L. powelli, the lack of a 

septum is a result of preservation or whether .this lack 

is a primary feature. Now that the presence of a 

median septum is proved for Lyosoma powelli, the assignment of these other species must be questioned until 

their inner lip features are known. 

Lyosoma powelli White 

Plate 2, figures 1-3, 7-10, 14 

1876. N eritina? powelli White, U.S. Geol. and Geog. Survey Terr. 

(Powell), p. 110, 111. 

1883. Lyosorna powelli ·white, U.S. Geol. and Geog. Survey Terr. 

(Hayden) 12th Ann. Rept. (for 1878), p. 152,153, pl. 38, 

figs. 6a-d. 

1899. Lyosorna p01celli 'Vhite. Stanton, U.S. Geol. Survey Mon. 

32, pt. 2, p. 630. 

1925. Desm-ieria (Lyosoma) powelli (White). Cossmann, Essais de paleoconchologie comparee, v. 13, p. 205, 206. 

1938. Otostorna ( Lyosoma) powelli (White). Wenz, Handbuch 

der PaHiozoologie; Gastropoda pt. 2, p. 418, fig. 1019. 

Diagnosis.-Whorls having a subsutural welt and angular periphery, both of which bear elongate nodes. 

Description.-N eritiform medium to moderately 

small low-spired shells; pleural angle 150°-160°. Shell 

about as high as wide. Whorl's rapidly expanding, 21h3 in number; suture slightly impressed. Whorls having 

a rather flat, narrow subsutural area bounded by a 

noded angulation; surface depressed or sulcate below 

angulation to the noded peripheral carination; below 

periphery, body rounds down rapidly. At maturity, 

near aperture, upper whorl surface is almost flat from 

suture to peripheral angulation. Sculpture dominated 

by thin strong collabral transverse ribs that form. elmigate nodes on angulations but that die out on base 

shortly below periphery. Growth lines, strong raised 

threads, strongly prosocline in trend between suture 

and upper whorl angulation, becoming more gently 

prosocline below. Aperture broad, open; outer lip 

slightly angulated in harmony with the whorl angulation. Inner lip well rounded and deeply excavated 

medially; medium septum, nondentate and inclined, 

having callus thickening extending to lower part of 

aperture. 

Af easurements.-

Locality 

Lectotype (USNM 144835) -------------------

Syntype (USNM 8181) ----------------------

24668-------------------------------------- 24668 ______________________________________ _ 

Ma:cimum 

Height diameter 

(mm) (mm) 

24.5 23.8 

21.9 22.2 

14.7 14.2 

10.5 10.9 

Discussion.-As indicated by the preceding measurements, the body proportions of shells of Lyosoma 

JW1lJelli maintain a uniform ratio through all the latter 

growth stages. In sculpture, however, there does appear to be considerable variation with growth. In the 

syntypic series (seven specimens, plus additional fragInents), one may note that the transverse 1riblets are 

more closely spaced on the early 'vhorls than on· the . 

latter whorls (pl. 2, contrast figs. 2, 9). The strength of 

the peripheral nodings also may vary much between 

individuals. The largest cotype (pl. 2, figs. 7-9), here 

selected as the lectotype (USNM 144835), shows a suppression of noding and a gradual loss of subsutural angulation. When the a peratural views of the lectotype 

(pl. 2, fig. 8) and that of the small hypotype (pl. 2, 

fig. 6) are compared it is seen that the outer lip angula.-

tion becomes rounded with increased size. This lends 

the aperture an almost quadrate outline. 

The preservation of some specimens is sufficient to 

retain traces of original color pattern. This coloration 

consists of at least two spiral bands. One band is situated on the upper whorl angulation; the second and 

wider band covers the lower pa.rt of the peripheral 

whorl angulation. 

Compared with Lyosorna enoda Sohl, which is from 

approximately the same stratigraphic interval, this 

species differs most noticeably in the presence of transverse ribs and nodings of the whorl angulations. Other 

species tentatively assigned to Lyosmna differ by having 

rather well-defined spiral sculpture. Another closely 

related, undescribed species occurs in the Preuss Sandstone on Dry Fork in Bingham County, Idaho (USGS 

28499), in the Hulett Sandstone Member (Callovian) 

of the "Lower Sundance Formation" (USGS 22078), 

in Fremont County, Wyo., and in the Rierdon Formation of Montana (pl. 2, fig. 4). This species, char-
D18 CONTRIBUTIONS TO PALEONTOLOGY 

acterized by its closely spaced sharp transverse ribs, 

seems to be a direct descendant of L. powelli and is restricted to beds of Callovian age. 

Lyosoma powelli has been cited in faunal lists as 

being of wide occurrence in the western interior. I have 

verifi~d its occurrence at 13 localities in Utah, Wyoming, and Montana. Although it is not abundant in 

Utah, L. powelli is the most widespread of the gastropod species represented in the Carmel Formation 

throughout the western interior. Throughout its geographic range only the n1ost minor and seemingly inconsistent variance in sculpture and body proportions 

can be detected. No consistent criteria for separation 

can be noted. The type lot from the mouth of Thistle 

Creek, Spanish Fork Canyon, Utah, contains the largest 

specimens of the species known. 

Types: Lectotype USNM 144835; syntypes USNM 144836, 

8181 ; hypotype USNM 144834. 

Occurrence: Utah: Carmel Formation at locs. 15C, 25, 32, 33; 

Twin Creek Limestone (member B) at loc. USGS 28458, near 

Thistle. Wyoming: Gypsum Spring Formation at loc. USGS 

4995, near Cody on the Shoshone River; Sundance Formation 

(lower) at locs. USGS 17651, 17652, 17669, 17670, 19337, 24668, 

Big Horn Basin; at loc. USGS 9246, Little Dry Gulch, 15 miles 

below Dubois, at loc. USGS 9230 Gros Ventre River, east of 

Jackson; Twin Creek Limestone (member B) at loc. USGS 

16036, near Lookout Peak, Afton quadrangle. Idaho: Twin 

Creek Limestone at loc. USGS 28585, Bingham County. 

Lyosoma enoda Sohl, new species 

Plate 2, figures 11-13, 15-24 

1877. Neritina? phaseolaris White (part), U.S. Geog. and Geol. 

Survey W. lOOth Meridian (Wheeler), v. 4, pt. 1, p. 

167-168, pl. 13, figs. le, lf, (not figs. la-c). 

Diagnosis.-Whorls having nonnoded subsutural 

welt and peripheral angulation. 

Description.-Medium to moderately small, lowspired shells; pleural angle 130°-145°. Whorls rapidly 

expanding, 2-3 in nmnber; sutures slightly impressed. 

Whorls having a rather flat, narrow subsutural area 

bounded below by a rounded welt; surface depressed or 

sulcate between welt and peripheral angulation; below 

periphery, body rounded. Body devoid of sculpture 

except for fine, usually faint growth lines. Color markings, as known, consisting of two moderately broad 

spiral bands of dark brown placed at the subsutural 

welt and peripheral carination respectively. Growth 

lines having a moderately high prosocline inclination 

( 30°) over entire length. Aperture broad, presumably 

constricted by a nondentate straight-edged septum; 

outer lip angulated at intersection, having subsutural 

welt and roundly angulated periphery, almost straight 

below periphery to rounded anterior; inner lip incompletely known. 

Measurements.-

Maa:imum 

Height diameter 

Locality ( mm) ( mm) 

23 (Holotype, USNM 144838) ------------------ 16 17. 5 

23------------------------------------------- 14.5 15.0 

Syntype N. phaseolaris (USNM 144837) ________ 7. 5 8. 0 

Disc1.Msion.-The syntypic series separated by White 

(1877, p. 167, USNM 8587) and described by him as 

N eritina? phaseolaris contains specimens here assigned 

to two species. Of the specimens White illustrated, the 

largest (1877, pl. 13, fig. 1e) is not contained in the 

U.S .. National Museum collections and is evidently lost. 

I herein designate as lectotype of White's species N eritina phaseolaris, the specimen figured by him on his 

plate 13, figures 1a, 1b, 1c. The remaining figured 

specimen, his figure 1d, is herein assigned to Lyosoma 

enoda (USNM 144837), which differs from N. phaseolaris by having a proportionally higher spire and by 

having a subsutural welt and peripheral angulations 

as well as less inclined growth lines. 

In shell proportions the known specimens of Lyosoma 

enoda are all very slightly wider than they are high. 

The strength of the subsutural welt and peripheral 

angulation varies moderately in sharpness. The most 

extreme variance in these features, however, appears to 

be on worn specimens; the wea:ring lends the body whorl 

a more rounded appearance than is typical. 

The median apertural septum characteristic of 

Lyosmna powelli has not been noted on any specimens 

of L. enoda. Its lack in known specimens of L. enoda 

is laid to vagaries of preservation. 

The close relationship of Lyosmna enoda and the type 

species L. powelli is well shown by their similar body 

proportions and whorl angulations as well as growthline trend. On the other hand, the two can be easily 

distinguished. L. enoda lacks noding on the subsutural 

welt and peripheral angulation and has a different pattern of coloration. 

Lyosmna enoda is restricted to beds of Bajocian and 

Bathonian age but appears to be related to undescribed 

forms in the Canyon Springs Sandstone Member of the 

"Lower Sundance Formation·~ of Wyoming and the 

Swift Formation (Oxfordian) of Montana. 

Types: Holotype USNM 144838; paratype USNlVI 144841; 

figured specimens USNM 144842, 144843, 144840, 144837, 144839 

(last two are former cotypes of N eritina phaseolaris) . 

Occurrence: Utah: Ca,rmel Formation at locs. 3, 4, 15B, 16, 

20, 21, 23, 26B, 27, on Salt Creek near Nephi, and questionably 

at locs. 9C, 10, 15A, 35, 39 ; Twin Creek Limestone (member B) 

at loc. USGS 17064, near Thistle, and at loc. USGS 21623, 

Duchesne County. Wyoming: "Lower Sundance Formation" 

at loc. USGS 17670 Sykes Mountain, 6¥2 miles north of Kane, 

Big Horn County. 
MARINE JURASSIC GASTROPODS, CENTRAL AND SOUTHERN UTAH Dl9 

Genus NERITINA Lamarck, 1816 

Type by opinion 119 of International Commission of 

Zoological Nomenclature ( 1931), N erita puligera Linne 

(1766). 

Discussion.-According to J{een and Cox (in Knight 

and others, 1960, p. I282) , this genus is restricted to the 

Eocene. The Jurassic species described here is included 

with question. In outline and growth fonn it simulates 

N eritina, but the full character of its shell is unknown, 

as no specimens preserve either the inner lip ca.llus or 

septum. Until better preserved specimens are found, it 

seems best to follow White's ( 1877) original placement 

and retain them with question in N eritina. 

Neritina 1 phaseolaris White 

Plate 3, figures 12-21 

1874. Neritina phaseolaris White, Prelim. Rept. Invertebrate 

Fossils, U.S. Geog. and Geol. Survey W. 100th Meridian 

(Wheeler) , p. 24. 

1877. Neritina? phaseolaris White (part), U.S. Geog. and Geol. 

Surveys W. 100th Meridian (Wheeler), v. 4, pt. 1, p. 

167-168, pl. 13, figs. la-c (not figs. ld, le.) 

1883. Lyosoma phaseolaris White, U.S. Geol. and Geog. Survey 

Terr. (Hayden), 12th Ann. Rept. (for 1878), p. 152. 

Diagnosis.-Low-spired neritid devoid of surface 

sculpture. 

Description.-Moderately small neritiform shells of 

subglobular out1ine. Spire very low, only slightly 

protruding above body of adult. Suture slightly impressed. Whorls expand ra.pidly, well rounded, and 

devoid of sculpture. Growth lines highly prosocline 

and straight, inclined about 53 ° from the horizontal. 

Aperture broad, outer lip well rounded, inner lip incompletely known, callus wash rather thin, protruding 

slightly onto body; septum unknown. 

lJfeasnrenz,ents.-The lectotype (USNM 144845) fron1 

Salt Creek near Nephi, Utah, measures 9 mm in height 

and lias a maximum dia1neter of about 13 mm. 

Discussion.-Shells closely conforming to the type 

specimen are rare in the Jurassic collections under 

study. The generalized shape and lack of sculpture 

cause difficulties in characterizing N eritina phaseolctris, 

and identification has rested on sha.pe and shell proportions. Amount· of variability within the species is 

poorly known because of the few specimens available 

from any given locality and because most show effects 

of abrasion, crushing, or weathering. All the specimens 

fr01n localities other than Nephi, cited under "Occurrence," have a low spire and smooth, rounded, unorna.-

mented whorls, but their identification n1ust be viewed 

as questionable. 

Compared with N eritina wyom·ingensis Stanton 

(1899, p. 629) from beds of Middle Jurassic age in 

Yellowstone Park, this species is much lower in outline 

and has much more highly inclined growth lines. 

Types: Lectotype USNM 144845; figured specimens 132843, 

144844, 144846. 

Occu.n·ence: Utah: Salt Creek near Nephi, Juab County. 

Carmel Formation, questionable occurrEmces at locs. 9D, 31A, 

32, 37A, 14B, 15C, 25. 

Genus NERIDOMUS Morris and Lycett, 1851 

Type by subsequent designation of Cossmann ( 1925, 

p. 187), N erita he1nisphaerica Morris and Lycett, 1851. 

Neridomus1 sp. 

Plate 1, figures 1~-21 

Discussion.-T-...vo specimens-one from the Arapien 

Shale of Sanpete County, Utah t.USGS 21448), and 

one from the Carmel Formation (loc. 25)-may belong 

to this genus; but the inner lip features are incompletely 

known and definite placement is therefore impossible. 

The figured speeimen is 1noderately small ( 9 mm high), 

has a low spire, and is about as high as it is wide. The 

whorls are well rounded and devoid of sculpture except 

for fine slightly arcuate prosocline growth lines. A few 

growth lines are sufficiently raised and strengthened to 

form a coarse surficial corrugation. The a.perture is 

broad and has a well-rounded outor lip. The inner lip 

is broken and preserves no trace of callus. 

Type: Figured specimen USNM 1448:51. 

Occurrence: Utah: Arapien Shale at loc. 2; Carmel Formation at loc. 25. 

Neritid gastroporlls 

Indeterminable internal molds or distorted specimens 

of gastropods probably belonging in this family and 

possibly to one of the species previously discussed are 

present in the collections from the Carmel Formation of 

Utah at localities 5, 15B, 18A, 19B, 25, 27, 34A, 34B, 36, 

and 37B. 

Superfamily AMBERLEYACE.A Wenz, 1938 

Family NODODELPHINULID.A.E Cox, 1960 

Genus NODODELPHINULA Cossmann, 1916 

Type by original designation, Delph,inula buckmani 

Morris and Lycett, 1851. 

Nododelphinula1 sp. 

Plate 1, figures 10-12 

Disc~tssion.-Several incompletn specimens from the 

Carmel Formation of Utah may represent the genus 

N ododelphinu.Za. All are incomplete but have a bicarinate periphery. One specimen (pl. 1, figs. 10, 12) from 

J(anab Canyon ( loc. 33) is an external mold lacking the 

aperture and umbilicus. It bears a spiral row of coarse 
D20 CONTRIBUTIONS TO PALEONTOLOGY 

nodes on the upper sloping whorl surface. The periphery is delimited above by a sharp strong nodose cadnation and below by a second hut ·weaker carination. 

Below the second carination, the body whorl constricts 

strongly. 

Another figured specimen (pl. 1, fig. 11) from Orderville Canyon (loc. 39) may belong to a different species, 

as the noded sculpture is absent. The specimen has hicarinate whorls, however, and the ~ack of nodes may he 

due to the poor preservation. 

One fragment (lTSNM 132638) ascribed to this speeies is part, of the rounded base of a specimen and bears 

three strong spinose lirations. 

Compared with the type species N. bu.ckn~ani (Morris 

and Lycett) from the Middle Jurassic of England, this 

speeies has a proportionally lower spire. The sculpture 

is n1ore highly nodose than is typieal of the genus, but 

transverse seulpture is probably not as strong. 

A similar and possibly eonspecific form is present in 

the Gypsum Spring Formation and "Lower Sundance 

Formation" of Wyoming. 

Types: Figured specimens USNM 144848. 132637; mentioned 

specimen USNM 132638. 

Occurt·ence: Utah: Carmel Formation at locs. 33, 34A, 37B, 

questionable occurrence at loc. 39. Wyoming: "Lower Sundance 

Formation" at USGS loc. 17670; Gypsum Spring Formation at 

USGS loc. 19357, Sykes Mountain. 

Family AM:BERLEYIDAE Wenz, 1938 

Genus AM:BERLEYA Morris and Lycett, 1851 

Type by subsequent designation, Arnberleya ba.thonica Cox and Arkell, 1950. 

Disc·ussion.-Although only one specimen from the 

Carmel Formation is here assigned to An~berleya, the 

genus is especially well represented in the Jurassic of 

the more northerly areas in Canada and Alaska. 

Amberleya ~ sp. 

Plate 1, figure 14 

Dismtss·ion.-The figured specimen consists of an 

internal and external mold of part of a body whorl. 

It is unique among the Carmel gastropods and appears 

to belong to a turbiniform speeies, possibly assignable 

to A·rnberleya. The whorl is round sided and covered 

by fine growth lines. Spiral sculpture is strong and 

consists of nodose eords that are weaker but more closely 

spaood on the basal slope than on the upper part of the 

whorl. A weak subsutural cord is followed by three 

stronger widely spaced cords over the rounded midwhorl and periphery. The cords are closely spaced on 

the basal slope but are not quite as broad as the spiral 

interspaces. The spacing and pattern of placement of 

these cords parallel those of A·mberleya densinodosa 

Huddleston (1887, p. 282) from the Bajocian of England, but the nodes of the spiral cords are coarser and 

less elosely spaced. 

Type: Figured specimen USNM 132639. 

Occurrence: Utah : Carmel Formation at loc. 16. 

Genus OOLITICIA Cossmann, 1894 

Type by original designation, Turbo phillipsii Morris 

and Lycett (1857, p.117) 

Ooliticia ~ sp. 

Plate 1, figure 5 

D·iscussion.-External molds of parts of shells from 

the Carmel Formation in Kanab Canyon, l{ane County, 

Utah, possess characters that suggest their placement in 

the genus Ooliticia. The shell is turbiniform having. 

a mode1rately high, tapering spire. The body whorl 

is rather well rounded, and the suture lies in a channel 

formed by the strong nodes of the subsutural cord. 

None of the speeimens preserve the apertural features. 

The sculpture of the base is obscured because of poor 

preservation, but sculpture of the whorl sides consists 

of two strong widely spaced coarsely noded spiral cords 

(pl. 1, fig. 5). The upper or suhsutura1 eord nodes 

project up and out, forming a trough between the cord 

and suture. 

In these features of sculpture this species is somewhat reminiscent of the specimen of Ooliticia sulcata 

(Hebert and Deslongchamps) figured by Huddleston 

(1887, pl. 23, fig. 15) from the Callovian of Great Britain. Generic placement of this species is tenuous because of laek of knowledge of the apertural features. 

Type: ]figured specimen USNM 144857. 

Occurrence: Utah: Carmel Formation at locs. 34A, 34B. 

Order MESOGASTROPODA Thiele, 1925 

Superfamily CERITHIACE·A Fleming, 1822 

Family PROCE,R.ITHIIDAE Cossmann, 1905 

Subfamily PROCERITHIINAE Cossmann, 1905 

Genus RHABDOCOLPUS Cossmann, 1906 

Type by original designation, AI elan·ia scalariforrnis 

Deshayes, 1830. 

Diagnosis.-Mediun1 to small turriculate shells 

having strong transverse ribs and spiral cords. Ribs 

subtuberculate at upper ends. 

Discussion.-Cossmann (1906, p. 27) proposed 

RhabdocolJYIM as a subgenus of Procerithiu,m Cossmann 

(1902). Both Walther (1951, p. 85) and Haas (1953, 

p. 234) treated Rhabdocolpus as a separate genus. 

Haas discussed the genus in detail, and his Peruvian 

species extend the range of the genus downward into the 
MARINE JURASSIC GASTROPODS, CENTRAL AND -SOUTHERN UTAH D21 

Triassic. The genus is widespread and well represented 

in the Jurassic rocks of many areas, but this is the first 

report of it from North America. Imlay ( 1941) reported two other members of the family, Oryptoptywis 

Cossmann and Xyst-rella Cossmann, in the Jurassic 

Smackover Formation of Arkansas. 

Rhadocolpus viriosus Sohl, new species 

Plate 3, :figures 1-6; plate 5, :figure 3 

Diagnosis.-Small turriculate shells having 6-8 transverse ribs crossed by 3 spiral ribbons. 

Description.-Shell small, slender, and turriculate. 

Pleural angle 20°-25°. Protoconch incompletely 

known, consisting of about two erect round-sided 

whorls expanding much more rapidly than teloconch 

whorls. Suture impressed, in part obscured by coronation of the transverse ribs of succeeding whorls. 

Whorls flat sided, base broadly convex, margin subangulate. First teloconch whorl smooth followed by 

whorls whose sculpture is dominated by 6-8 direct 

strong transverse ribs that are coronate or noded at 

their posterior extremity and die out at basal angulation. Spiral sculpture strongest on early whorls consisting of three spiral ribbons that override transverse 

ribs but are strongest in rib interspaces; ribbons weaken 

and are more widely spaced on later whorls; on body 

whorl, spiral sculpture of weak to obsolete ribbons on 

sides having secondary spiral lirae and low cords on 

base. Aperture incompletely known, subovate, rounded 

anteriorly, angulate posteriorly. 

M easurernents.-

Maximum 

Height diameter 

Locality ( mm) ( mm) 

25----------------------------------------- 3.75 1.55 

25----------------------------------------- 4.75 1.9 

8----------------------------------------- 4.251- 1.8 

Discussion.-This small species is one of the more 

common gastropods in the Carmel Formation of Utah 

and occurs in similar profusion in certain zones of the 

Twin Creek Limestone. In both formations it occurs 

with the "winnowed" small fauna that contains abundant Oylindrobullina sp. and small turriculate and trochiform species (pl. 5, fig. 3). 

Variation in shape is slight, but, as can be seen by 

the illustrations, strength of sculpture does vary. Some 

specimens show well-developed spiral sculpture (pl. 3, 

fig. 2), but others (pl. 3, fig. 1) almost lack it. Similarly, the ribs can be strong and coronate above (pl. 3, 

fig. 6) or only low folds, depending in part on the state 

of preservation. Most of these specimens are from 

weathered limestone surfaces, and their sculpture may 

be subdued owing to surficial solution. The mode of occurrence indicates at least moderate transport, and thus 

shell wear can be expected. 

No other species of the genus have been described 

from the Jurassic of North America. Except for being 

much smaller, Rhabdocolpus viriosus compares well in 

sculpture and shape with the type species R. scalariforme (Deslongchamps) from the Bajocian of Normandy, France. 

Types: Holotype USNM 144856; paratypes USNM 144852-

144855, 14846. 

Occm·rence: Utah: Carmel Formation at locs. 7B, 8, 9A-D, 

14A, 15C, 19A, 19B, 24, 25, 26A, 26B, 33, and questionable 

occurrences at locs. 15B, 29, 34; Twin Creek Limestone at locs. 

USGS 28457 and 28459 on Crab Creek near 'Thistle, Utah County. 

Genus PROCERITHIUM Cossmann, 1902 

Type by original designation, Procerithiurn quinquegr'anosurn Cossmann. 

Procerithium 1 sp. 

Plate 3, :figures 8-11 

Dismtssion.-Several small slender, high-spired specimens having strong spiral sculpture but lacking transverse sculpture have been found in the collections from 

the Carmel Formation. 

The shells measure as much as !:> mm in height and 

have a maximum diameter of 2.5 mm. The whorls are 

flat sided, having a narrow flat subsutural shelf. Sculp· 

ture appears to be limited to thin spirallirae that cover 

the whorl sides. The aperture is incompletely known. 

Specimens belonging to this species are rare. The 

proportionately long whorl and its sculpture are most 

reminiscent of Oerithium abbas Huddleston (1887, p. 

172) of the Jurassic "Sowerbyi-bed" of England. Compared with that species, these shells are much smaller, 

and the posterior shelf develops at a much earlier stage. 

The state of preservation of these specimens obviates 

further comparison. 

Types: Figured ·specimens USNM 144858-144861. 

Occurrence: Utah : Carmel Formation a.t loc. 26B. 

Superfamily PSEUDOMELANIACEA Pchelintsef, 1960 

Family PSEUDOMELANIIDAE Fischer, 1885 

Genus PSEUDOMELANIA Pic~et and Campiche, 1862 

Type by original designation, Pseudomelania gresslyi 

Pictet and Campiche. 

Pseudomelania 1 sp. 

Plate 3, :figure 7 

Disc~tssion.-Small aciculate smooth-surfaced shells 

are common at several localities in the Carmel Forma,-

tion of Utah. Their assignment to Pseudomelania is 

questioned, as the growth-line character and apertural 
D22 CONTRIBUTIONS TO PALEONTOLOGY 

features are unknown. The shells are 7-10 mm long 

and 2-2.5 mm in diameter. The whorls are almost flat 

sided, the basal slope is rounded, and the surface is 

devoid of sculpture. The sutures are narrowly grooved. 

This species occurs with the other small gastropods in 

the fauna in what appear to be "winnowed" size concentrations. The state of preservation is such that the 

growth lines cannot be discerned. 

Type: Figured specimen USNM 144857. 

Occurrence: Utah: Carmel Formation at locs. 19B, 26A; Twin 

Creek Limestone at loc. USGS 28458 on Crab Creek near Thistle, 

Utah County. 

Turriculate gastropods indeterminate 

Small slender gastropods that are too poorly preserved to allow generic assignment occur at localities 3, 

7B, 15B, and 15C, and in the Twin Creek Limestone 

near Thistle, Utah (pl. 5, fig. 2). In general, the specimens are badly weathered, but in outline they resemble 

Rhabdocolpus or Pseudmnelania. They probably represent one or the other of these forms, as indicated by 

their occurrence with other elements of the small gastropod fauna. discussed before. 

Superfamily NATICACEA. Theile, 1929 

Family NATICIDAE. Forbes, 1838 

Representatives of this family are moderately comnlon in the Carmel Formation of Utah. Except for a 

few partially silicified specimens, they are poorly preserved and for the most pa.rt consist of internal molds 

in various states of completeness. They can be divided 

into two groups, one representing Tylostoma-like species and the other a smaller naticid akin to Globularia. 

Genus TYLOSTOM:A Sharpe, 1849 

Type by subsequent designation (W enz, 1941, p. 

1026), Tylostoma globosum Sharpe. 

Discussion.-The type species is based on large 

globose, naticoid internal molds from the Turonian of 

Portugal. Since its proposal, Tylostoma has served as 

a receptacle for generically indeterminable globose 

naticids of large size. -

Tylostoma t sp. 

Plate 4, :figures 16, 19 

Discussion.-A moderate number of internal molds 

generally conforming in shape to the figured specimens 

occur at 11 localities in the Carmel formation. All localities are in the middle area (fig. 1) of outcrop of the 

Carmel Formation. 

None of the molds show surface or umbilical characters; and as some are distorted or fragmental, it is impossible to s.a.y that they an represent the &'lme species. 

In all specimens the whorls are well rounded and have 

some indication of a subsutural flattened or ramplike 

area. One specimen shows the inner lip to be strongly 

excavated medially, as one would expect in shells having globose whorls. No trace of external ornament is 

known except for a faint suggestion that there may have 

been several transverse rugae near the aperture. 

Types: Figured specimens USNM 132641, 144844. 

Occurrence: Utah: Carmel Formation at locs. 1:5A, 17A, 17B, 

18B, 18C, 33, 35, 37B, 38A, 38B, 41 ; Wyoming: questionable 

similar species occur in the Gypsum Spring Formation, Canyon 

Springs Sandstone Member of the Sundance Formation and the 

"Lower Sundance Formation." 

Subfamily GLOBULARIINAE Wenz, 1941 

[Ampullininae] 

Genus GLOBULARIA Swainson, 1840 

Type by subsequent designation (Hermannsen, 1847), 

Ampullaria sigaret-ina Lamarck, 1804. 

Discussion.-In general, it is somewhat questionable 

whether any Jurassic shells assigned here actually belong in Globularia. For example, the species from the 

Great Oolite assigned by Cox and Arkell ( 1950, p. 83, 

84) an have a proportionally higher spire and an aperture that is more expanded laterally than is typical of 

the type and other associated Eocene species. The specimens from the Carmel Formation treated in the following description are similar in character to those 

from the British Jurassic. 

Globularia 1 sp. 

Plate 4, :figures 10---15 

Dismtssion.-Nine specimens from the Carmel Formation on Deep Creek in Garfield County, Utah (loc. 

31B), preserved sufficient character to allow at least a 

tenuous placement. They are all partially silicified, 

but the replacement is coarse and is of a beikitic nature 

that does not allow for the preservation of fine detail. 

The shell is globose and moderately small for the genus 

and has a spire proportionally higher than is typical 

for the genus. The aperture is broad and well rounded 

anteriorly. The inner lip is incompletely preserved on 

all specimens, but an umbilical chink is present. Some 

specimens suggest that this chink is covered by an urnbilical sheath in complete specimens. 

Types: Figured specimens USNM 144871-144875. 

Occurrence: Utah: Carmel Formation at locs. 15A, 31B, 37B, 

38B. 

Naticiform gastropods 

Generically indeterminate naticiform gastropods 

occur in the Cannel Formation at localities 1, 6, 9C, 9D, 

12, 16, 31A, and questionably at locality 20. For the 

most part they are preserved as internal molds of rather 
MARINE JURASSIC GASTROPODS, CENTRAL AND SOUTHERN UTAH D23 

small size. Some may represent additional specimens 

of those herein assigned to Globularia? sp. 

Subclass EUTHYNEURA Spengel, 1881 

Order ENTOMOTAENIATA Cossmann, 1896 

Superfamily NERINEACEA W enz, 1940 

Family NERINEIDAE Zittel, 1873 

N erineid gastropods are among the most common 

snails found in the Jurassic rocks of the western interior. In the Carmel Formation they are represented 

by at least two and perhaps three, species; and in terms 

of abundance they are the most numerous of the larger 

snails. Although these species, because of their sim pie 

arrangement of internal plaits, seem best placed in 0 ossnwnnea, most other North American Jurassic described 

species seem to belong in other genera. 

Genus ·COSSMANNEA Pchelintsev, 1931 

Type by original designation, N er.Znea desvoidyi 

d'Orbigny, 1850. 

Di-Bmtssion.-This genus is characterized by elongate, 

rather slender shells whose whorl sides are strongly to 

moderately concave and have a swollen or weltlike 

sutural area. The aperture is rhomboidal and has a 

short anterior canal. Cox ( 1948, p. 250) stated that two 

folds are present internally, one on the columella and 

one on the labial wall. The type species, 0 ossmannea 

desvoidyi ( d'Orbigny) ( 1850, pl. 261) as originally 

figured, shows a rather weak columellar fold low on the 

columella, plus one fold on the outer wall. Pchelintsev 

(in Pchelintsev and Korobkov, 1960, pl. 12, fig. 8B) 

figured 0. subdesvoidyi as having only the most faint 

and broad plications. The Carmel species described 

below fit well within this prescribed range. 

Species other than those treated in the following 

description occ.ur in the western interior Jurassic. They 

are especially abundant in the Gypsum Spring Formation but also occur in the "Lower Sundance Formation," 

the Preuss Sandstone, and questionably in the Piper 

and Sawtooth Formations. 

Cossmannea imlayi Sorl, new species 

Plate 4, figures 1-8 

Diagnosis.-,Vhorl sides concave, having greatest 

constriction at lmver one-third of whorl; columellar 

fold developed late in growth as a faint, low swelling. 

Description.-Elongate, slender, multi whorled shells. 

Protoconch unknown, pleural angle 9°-15°. Whorls 

concave sided having deepest part of concavity about 

two-thirds of the distance between upper and lower 

suture; sutural area swollen, suture being in a narrow 

groove. Body whorl basally carinate; on spire, basal 

carination slightly protruding over succeeding whorl. 

Growth lines sigmoidal on whorl sides. Aperture incompletely known, rhomboidal in outline; internally 

one plait on the midlabial surface persisting from the 

earliest whorls, but the low, rounded obscure columellar 

fold did not develop until a late growth stage. 

M easurements.-One specimen that lacks about 12 

mm of its apical tip measures 62.5 mm in length and 15 

mm in diameter. Less complete specimens indicate that 

this species grew to a larger size. These specimens have 

a maximum diameter of about 19 mm and, by extra polation from known proportions of smaller specimens, may 

have attained a length of 90-100 mm. 

Discu:ssion.-This species is abundant at its type 

locality on Deep Creek, Garfield COunty, Utah (loc. 

31B, 31C) ; more than 100 incomplete specimens are 

available for study. Variation within the type lot is 

difficult to measure because the coa.rse beikitic replacement of the shell material masks the finer features of 

ornament and because of wear and the effects of compression on some specimens. For example., it is difficult 

to ascertain whether the variation in the amount of 

swelling at the sutural area is natural or if it is a function of the amount of wear or abrasion that .the shell has 

undergone. Moderate variability in shell outline is 

shown by the apical angle range of 9°-15°. Internally 

the strength of the plait on the labial surfa.ce (pl. 4, 

compare figs. 7 and 8) is variable. Some specimens 

(pl. 4, fig. 5) possess a faint subsutural spiral cord similar to that on the type species Ooss11Ulnnea desvoidyi. 

Other specimens do not show this feature, but it may be 

obscured because of the coarse silica replacement. The 

specimens assigned to this species from localities other 

than the type locality are invariably smaller. This leads 

one to question their assignment to the species. They 

do, however, possess the same internal plication plan 

and swollen subsutural area and compare well in shape 

with the early growth stages of the larger specimens 

from the type locality. 

I place this species in the genus 0 ossmannea with 

some misgivings. It compares closely with the type 

species 0. desvoidyi from the Oxfordian of France in 

shape, sutural character, and growth line; but, internally, it lacks the strong columellar plait. However, 

0. subdesvoidyi Pchelintsev (1960) shows a similar 

weak fold low on the columellar surface. If 0. subdesvoidyi is properly assigned, then 0. i1nlayi falls 

well within the range of Ooss11Wnnea. 

The species is named in honor of R. W. Imlay of the 

U.S. Geological Survey. 

Types: Holotype USNM H4864; paratypes USNM 14861-

14863, 14865-14867. 

Occurrence: Utah: Carmel Formation at locs. 12, 13A, 13B, 
D24 CONTRIBUTIONS TO PALEONTOLOGY 

18A, 21, 30, 31A, 31B, 31C, 34A, 34B, and questionable occurrence at locs. 16, 25, 33, 40; Idaho: Twin Creek Limestone at 

loc. USGS 28586, Bingham County ; Wyoming: Twin Creek 

Limestone (member B) at loc. USGS 16036, Afton quadrangle. 

Cossmannea' kanabensis Sohl, new species 

Plate 4, figures 9, 17, 18 

Diagnosis.-'Vhorl sides flat, lackin·g a pronounced 

sutural welt. 

Description.-Shells small for genus, multiwhorled, 

elongate, having a slender, even tapering spire. Pleural 

angle about 15°-18°; suture in a shailow groove. 

Whorls flat sided, covered by faint microscopic spiral 

threads of which the immediate subsutural thread is 

the finest. Body whorl basally carinate. Aperture 

rhomboidal, anterior canal moderately short and indined; outer lip having a strong plication situated 

medially, columellar lip slightly swollen above canal. 

Jfeasurements.-The holotype (USNM 144864) measures about 25 mm in height and 6 mm in diameter. A 

paratype (lTSNM 144863) has almost exactly the same 

measure.ments. 

Discussion.-This species is readily distinguishable 

from Ooss1nannea hnlayi, which also oceurs in the :Carmel Formation, by its flat-sided whorls; but because of 

this same feature, its plaeement in Oossmannea is very 

tenuous. The arrangement of the inten1al plications is, 

however, very similar to that of 0. imlayi. 

Types: Holotype USNM 144869; paratypes USNM 144868, 

144870. 

Occurrence: Utah: Carmel Formation at locs. 34A, 37B, 40. 

Undetermined nerineids 

Discussion.-Nerineid gastropods occur at other localities in the Carmel Formation, Utah. Unfortunately, 

they are so poorly preserved that they cannot be assigned to one of the speeies deseribed here. Such gastropods have been found at localities 22, 28, 34A, 34B~ 

38B, and 42. 

Order CEPHALASPIDEA Fischer 1883 

Superfamily ACTEONACEA d'Orbigny, 1842 

Family ACTEONIDAE d'Orbigny, 1842 

Genus CYLINDROBULLINA von Ammon, 1878 

Type by original designation, Acteonina fra.gilis 

Dunker. 

Disenssion.-The most recent comprehensive classification of the family Acteonidae is that of Zilch (1959). 

He included Oylindrobullina as a synonym of Acteonina d'Orbigny. Acteonina, however, is characterized by having a low fold on the columella, a low spire, 

and a collar above the suture. Oylindrobullina has a 

smooth columella and a subsutural eollar. 

Part of the confusion regarding these genera may 

have arisen because both Fischer (1883) and Cossmann 

(1895) ignored Meek's (1863) designation of Ohemnitzia carbonaria Koninck ( 1843) as the type species of 

Acteonina. This led Cossmann to consider a smooth 

columella as typical of Acteonina. Knight (1941, p. 31) 

showed that this is not characteristic of the type species. 

Other authors (Cox and Arkell 1948; Walther, 1951) 

considered Oylindrobullina as either a ~parate genus 

or a subgenus of Acteonina. 

Cylindrobullina' sp. 

Plate 1, figures 1~17, plate 5, figure 1 

Discu.ssion.-Small opisthobranch shells that are 

close to Oylindrobu.llina in terms of their stair-stepped 

spire, broadly globose whorls, and well developed 

shoulder are abundant in the Carmel Formation. Unfortunately, no specimens preserve the char~cters of 

the aperture sufficiently well to ensure genenc placement. The surface of the shells is devoid of sculpture, 

and the shoulders are rounded. In these features they 

are similar to Oylindrobullina bulimoides (Morris and 

Lycett) from the Great Oolite of Great Britain, but 

have less convex-sided whorls and a more elongate 

aperture. 

The lack of sculpture may be due to the type of preservation. However, the group of opisthobranchs to 

which Oylindrobullina belongs usually have very subdued sculpture that is commonly restricted to the anterior part of the shell. Cut sections of the species show 

no evidence of columellar plications. 

Although the generic position of these specimens is 

doubtful, they are among the more widespread and 

abundant gastropods in the Carmel Formation of 

Utah. They apparently also oceur in the Twin Creek 

Limestone in northern Utah. 

Types: Figured specimens USNM 132640, 144849, 144850. 

Occurrence: Utah: Carmel F-ormation at locs. 3, 7B, 8, 9A, 

9C, 9D, 9E, 11, 14B, 15B, 16, 19A, 19B, 25, 26A, 26B, 29, 33; 

'Dwin Creek Limestone at locs. USGS 28457-28459 on Crab 

Creek near Thistle, Utah County ; Idaho : questionable occurrences in the Twin Creek Limestone (member B) at locs. USGS 

28500, 28506. Willow Creek, Bingham County. 

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MARINE JURASSIC GASTROPODS, CENTRAL AND SOUTHERN UTAH D25 

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D26 CONTRIBUTIONS TO PALEONTOLOGY 

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A Page 

abbas, Cerithium ______________________________ D21 

Abundance of the gastropod fauna____________ 5 

Acknowledgments____________________________ 2 · 

Acteonacea _________________________________ 9, 14,24 

Acteonidae_ ---------------------------- ____ 9,14, 24 Acteonina___ __ _________ __ __ ____ _ __ __ _ ___ _ __ _ __ 24 

fragilis __ ------- _ ------ ____ ___ _ ___ _ __ _ __ _ _ 24 

maloniana __ _ --------------- _ ___ _____ ___ _ _ _ _ _ _ 9, 14 

Alaska ___ ---------___________________________ 12 

Amberleya __ ----------------------------- _____ 12,20 

bathonica_______________ ___ ___ ___ ____ _ ___ __ 20 

delia_--------------- ______________________ 13, 14 

densinodosa __ ------- ___________________ 12,14, 20 

dillerL __ _________________________________ 12, 14 

ornata _____________________________________ 12, 14 

sp _____________________ 6, 12, 13, 14, 20; pl. 1 

Amberleyacea __ ------------------------- 9, 13, 14, 19 

Amberleyidae ________ ------------------------- 14,20 

Ampullininae__________ _________ ____ _ _ ___ ____ _ 22 

Analysis of the gastropod fauna______________ 4 

anglicus, Trochus _______________ -------------- 15 

angulata, Phaneroptyxis___ ___ _ __ _ _ _ __ _ _ __ ___ __ 9, 14 

Aporrhaidae________ _ ___ ___ _ __ ___ _ _______ ___ __ 14 

Aptyxiella circumvoluta________________________ 14 

(Nerinoides) stantoni______________________ 9 

Archaeogastropoda ________________________ 13,14,15 

arcuiferum, Cerithium _________________________ 9,14 

B 

bathonica, Amberleya__________________________ 20 

benahensis, Lisochilus_________________________ 17 

beneclathratus, Turbo__________________________ 9,13 

bicarinata, Stomatia__ _ _ __ _ ___ _ _____ _ _ _ _ __ _ _ _ _ _ 17 

bilabiata, Globularia____ __ _ __ _ _ _ _ ___ ____ __ _ _ _ _ _ 14 

Natica_______________ _ __ _ __ _ ___ ___ _ _____ _ __ 9 

borealis, Pleurotomaria ________________________ 13,15 

buckmani, Delphinula_________________________ 19 

Nododelphinula ___ ------------------------ 20 Buckmanina sp _______________________________ 10,13 

bulimoides, Cylindrobullina____________________ 24 

burckhardti, Turritella____ __ _ _ ___ __ _ ____ _ _ _ __ _ _ 9, 14 

c 

californica, Itieria ______ ________________________ 12, 14 

Camptonectes __ ------------------------------- 7 Canada_______________________________________ 12 

cancellata, Purpurina __________________________ 11,14 

Canyon Springs Sandstone Member of the 

Sundance Formation_____________ 11 

capduri, Neritina______________________________ 17 

carbonaria, Chemnitzia________________________ 24 

Carmel Formation ____ -----------------------

Cephalaspidea _________ ---------------------- 14, 24 

Ceritella tindonensis __ --------------------- ____ 10, 14 sp _ _ _ __ _ _ _____ ___ __ _ _ __ _ __ _ _ _ _ _ __ _ __ __ _ __ _ 11 

Ceritellidae___ _ ___ _ ___ _ _ _ _ __ __ ___ _ _ _ ___ _ _ _ __ _ _ 14 

Cerithiacea ______________________________ 9, 13,14, 20 

Cerithiidae ___ ------- __ _ ___ ___ ___ _ _ ___ _ _ __ _ _ _ _ 14 

Cerithium abbas_______________________________ 21 

arcuiferum ___ ---------------------------- 9, 14 paskentaensis ___________________ ------ __ __ 12 

Chaetopoda __ --------------------------------- 9 Chemnitzia carbonaria_________________________ 24 

Chinitna Formation__________________________ 13 

INDEX 

[Italic numbers indicate major references and descriptions] 

Page 

circumtrunca, Pleurotomaria ___ ----------- D9, 13,15 

circumvoluta, Aptyxiella ---------------------- 14 N erinea__ _____ ___ _ __ _____ ___ _ _ __ __ _ __ _ _ _ _ _ 9 

Cloughtonia pyramidata_------------------- 10, 13,14 

SP---------------------------------------- 12,14 

cornejoi, Vermetus ___ ------------------------- 9 

corrugatus, Symmetrocapulus ______ 6, 13, 15; pl. 1 

Cossmannea __ ------------------------ __ 10, 11,14, 23 

desvoidyL _ -------------------------------- 23 imlayi _____________________ 6, 8, 10, 14, 23, 24; pl. 4 

kanabensis _______________________ 6, 14, 24; pl. 4 

subdesvoidyi. _ --------- _______ --- _ -- _ -- __ _ _ 23 

sp __ -------------------------------------- 11 

spp ________________ ----------------------- 14 Cryptoptyxis___ _ __ __ __ _ _ _ _ __ _ _ _ _ __ _ __ ___ ___ __ _ 21 

diversicostata______________________________ 9,14 

formosa _____________________ -------------- 9, 14 

grimaldi__----------------------------____ 9,14 

Cyclostrematidae ___ ------------------------ __ 15 

Cylindrobullina_ ------------------------------ 6, 24 

bulimoides __ ------------------------------ 24 sp ___________________ 6,10, 11,13,14, 21,24; pl. 1 

D 

delia, Amberleya __ _ --------------------------- 13,14 

Delphinula buckmanL________________________ 19 

stantoni_ _____ ___ -------------------------- 9 

densinodosa, Amberleya __ ------------------ 12,14, 20 

Desmieria (Lyosoma) powelli__________________ 17 

desooidyi, Cossmannea_________________________ 23 

Nerinea __ _______ ----- ____________ --- ____ -- 23 

Dicroloma ___ --------------------------------- 11 

sp ____ ------------------------------------ 11,14 dilleri, Amberleya _____________________________ 12,14 

di!'ersicostata, Cryptoptyxis ____________________ 9,14 

Division of Carmel Formation________________ 1 

E 

elaborata, Purpurina ___ _______________________ 12, 14 

enoda, Lyosoma ____________ 6, 7, 10, 11, 14, 17,18; pl. 2 

Entomotaeniata ______________________________ 14,23 

eudesii, Nerinea _______________________________ 9,14 

Euthyneura _______________________________ 13,14, 23 

Exelissia sp ___________________________________ 11,14 

F 

Fernie Shale_________________________________ 12 

ferniensis, Turbo______________________________ 12 

Ooliticia ---------------------------------- 14 jinlayensis, Globularia_ _ __ _ ___________________ 14 

Natica ----------------------------------- 9 

Nerita ------------------------------------ 9,14 

formosa, Cryptoptyxis_________________________ 9,14 

fragilis, Acteonina_____________________________ 24 

G 

Gastropoda___________________________________ 15 

Geographic distribution______________________ 7 

globosum, Tylostoma__________________________ 2 

Globularia_ _ ______ __ ____ _ ___ __ _______ _ __ __ ___ _ 9, 22 

bilabiata _________ ----------------- _ ___ _____ 14 

jinlayensis ____ --------------------------- 14 

Page 

Globularia injlecta __ -------------------------- D14 williamsL___ ____ _________ __ __ _ __ _ ___ ______ 14 

sp _____________________________ 6, 14, 22, 23; pl. 4 

Globulariinae __ -------------------- _________ _ 22 

goodelli, Nerinea ______________________________ 9,14 

Pseudomelania_ _ _______ ________ __________ 9,14 

Green Beds of the Fernie Shale_______________ 12 

gresslyi, Pseudomelania_______________________ 21 

Grey Beds ot the Fernie Shale________________ 12 

grimaldi, Cryptoptyxis _ _ ____________ __________ 9, 14 

Gulf coast of United States___________________ 8 

Gypsum Spring Formation ______________ . _ _ _ 10 

H 

hamptonensis, Metriomphalus _________________ 12,14 

Harpagodes _________ ---------------------- __ __ 14 

sp_ ------------ _ __ _______ ___ ____ __ ____ __ __ 8 

hellona, Purpurina ____________________________ 13,14 

hemisphaerica, Nerita ___ -------------------- __ 19 

hinchmanensis, Trochus _______________________ 12,13 

Hulett Sandstone Member of the Sundance 

Formation________________________ 11 

Hypsipleura occidentalis __ -------------------- 12 

imlayi, Cossmannea ___________ 6,8,10,14,23,24; pl.4 

injlecta, Globularia____________________________ 14 

Natica ------- ___________________________ -- 9 

Introduction __ ------------------------------- Itieria californica __ __________________________ -- 12, 14 

Itieriidae_ ________ ___ ___ __ __________________ __ 9, 14 

J 

Jurassic gastropods of North America, survey of.________________________________ 8 

K 

kanabensis, Cossmannea ______________ 6, 14, 24; pl. 4 

Kialagvik Formation ____________________ ----- 12 

L 

Leptomaria _________ -------------------------- 10, 13 

leymeriei, Oonia _____ -------------------------- 14 

Pseudomelania (Oonia) ____________________ 12,13 

Lias Formation_______________________________ 8 

liasinus, Scalaria__________ __ _ ____ _____ _____ ___ 9 

Lissochilus _____ _____________________________ -- 16 

benahensis _____________ ___________________ - 17 

Littorinacea__ ___ _ __ __________ __ _ __ _ __ ___ _ _ _ __ 14 

Lower Sundance Formation__________________ 10 

Lyosoma ____________________________ 6, 8, 11,16; pl. 2 

enoda ________________ 6, 7, 10, 11, 14, 17, 18; pl. 2 

phaseolaris ____ ·--- _________________ • _ __ ___ 19 

powelli_ ____________ 6, 8, 10, 11, 14, 16, 17, 18; pl. 2 

squamosum _______ ___________ -------------

(Lyosoma) powelli, Desmieria _________________ _ 

powelli, Otostoma ____________________ -----

M 

17 

17 

17 

Malone Formation____________________________ 9 

maloniana, Acteonina _________________________ 9,14 

D27 
D28 

Page 

Margarites sp. ______________________________ D12, 13 

Melania scalariformis___ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 20 

Mesogastropoda ________ ---------------------- 14,20 

Metriomphalus____ ______ _ ___ ___ _ _____ _________ 9 

hamptonensis _____________________________ 12,14 

stantoni_ ____ _ ---------- _____ __ _____ _ __ ___ _ 14 

Mexico. __ ----------__________________________ 8 

michinhamptonense, Procerithium ______________ 13,14 

Monodonta __________________________ __________ 12, 13 

Morrison Formation__________________________ 10 

N 

Naknek Formation, lower part oL___________ 13 

upper part of----------------------------- 13 Natica bilabiata_______________ ________________ 9 

jinlayensi8 __ _ ___ _ ___ _ _____ __ __ _ __ _ ____ _ ___ 9 

injlecta _ _ ____ _ ___ _ ________ _ _ __ _________ __ _ 9 

williamsi ____ ______ _ ___ _______ __ _ __________ 9 

Naticacea ________________________________ 9, 13, 14,22 

Naticid gastropods.----------------------____ 8,$2 

Naticidae ___________________________________ 9, 14,22 

Naticids____ ________ _____________ _________ ____ 14 

Naticiform gastropods ___________________ 6, 10,11,22 

Neridomus___________ __ _____ ______ __ ____ _ _____ 19 

sp ___________________________________ 6, 19; pl. 1 

Nerinea circumvoluta__________________________ 9 

desvoidyi_ ____ ___________ ------------------- 23 

eudesiL ___ -------------------------------- 9, 14 goodelli____________________________________ 9,14 

thompsonensi8 _____________________________ 12, 14 

turbatric __________________ _______ ---------- 9, 14 

SP-------------------------------------- 10, 13,14 

Nerineacea __ ---------------------------- 9, 13, 14, 23 

Nerineid gastropods__________________________ 6 

Nerineidae _________________________________ 9, 14,23 

Nerineids ________________________________ 8, 10, 14,$4 

Nerinella stantoni_____________________________ 9 sp _ __ _ _ _ _ __ _ _ __ ___ _ __ _ _ _ _ _ _ _ __ __ ___ _ _ _ _ _ _ 9 

Nerinoides stantonL ____ ---------------------- 14 sp ___ ------ ____ --- _ ___ _ ___ _ _ __ _ _ _ _ ___ _ _ __ _ 14 

(Nerinoides) stantoni, Aptyxiella_______________ 9 

Nerita. __ ------- ____ _ ___ __ _ _____ __ _ _ __ _ __ _ _ _ __ 16 

jinlayensis________________________________ 9,14 

hemisphaerica_ _ __ ____ _ ___ _ _ __ _ _ __ _ _ __ _ _ __ _ 19 

nodolirata ________ _ ----------------------- _ 9 

peroblata__________________________________ 9,14 

puligera_____ _ __ _ _ _ ___ __ _ _ ____ ___ _ _ _ _ _ __ _ _ _ 19 

Neritacea ________________________________ 9, 13, 14,16 

Neritid gastropods---------------------------- 6,19 Neritidae ________________________________ 9, 13, 14,16 

Neritina _________________ --------------------- 16, 19 

capduri_ __________ ------------------------ 17 

phaseolaris ______________ 6, 9, 14, 16, 17, 18, 19; pl. 3 

powelli __________________________________ 9, 16,17 

wyomingensis ________________________ 9, 11, 14,19 

SP------------------------------------- 10, 11,14 Neritininae_____ _ _ _ _ _ _ _ _ ___ _ ____ _ _ _ __ _ ___ _ _ _ _ _ 16 

Neritoma (Oncochilus) occidentalis_____________ 9 

Neritopsidae ___________ ---------- ____________ 14 

Neritopsis SP---------------------------------- 9,14 

Nododelphinula_______________________________ 6,19 

buckmani_ ____ --------------- _ _ ___________ 20 

SP--------------------------- 6, 10, 11, 14, 19,· pl. 1 Nododelphinulidae _________________________ 9, 14,19 

nodolirata, Nerita_____________________________ 9 

Trachynerita _____________ ----------- ______ 14 

Nordegg Member of the Fernie Shale_________ 12 

Notes on ecology ___ -------------------------- 6 

0 

occidentalis, Hypsipleura______________________ 12 

Neritoma (Oncochilus)____________________ 9 

Otostoma_ _ ___ _ _ __ ____ _ ___ __ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 14 

Paracerithium __ ------------------------ __ 14 

(Oncochilus) occidentalis, Neritoma____________ 9 Ooliticia ____________________________________ 6, 12,20 

ferniensis____ _ __ _ _ _ _ _ __ _____ __ _ _ _ _ _ _ ___ _ _ _ _ 14 

INDEX 

Page 

Ooliticia paskentaensis_________________________ D14 

sulcata __ _________________________ ---- __ --- 20 

sp __ ------------------------------ 6, 14, $0; pl. 1 

Oonia leymerieL ____ -------------------------- 14 

subglobosa -------------------------------- 12, 14 

sp ---------------------------------------- 10,14 ( Oonia) leymeriei, Pseudomelania ____________ __ 12,13 

subglobosa, Pseudomelania________________ 12 

ornata, Amberleya _____________________________ 12, 14 

ornatissima, Stomatia. ____ -------------------- 17 

Otostoma_ ------------------- _ ---------------- 16 occidentalis _____________ ____ --------------- 14 

(Lyosoma) powellL_______________________ 17 

p 

Pacific coast of United States_________________ 12 

Paracerithium_ ------------------------------- 12 

occidentalis ___________ _ -------------------- 14 

paskentaensis ..• _____________ ---- ___ ------- 14 

paskentaensis, Cerithium ________ -------------- 12 

Ooliticia __________________________ --------- 14 

Paracerithittm __ ___ ------------------------ 14 

Turbo _____________ ------------------------ 12 

Patella rugosa __________ --------_-------------- 15 

Patellacea ______________________ -------------- 13, 15 

peroblata, Nerita______________________________ 9,14 

Phaneroptyxis angulata________________________ 9,14 

phaseolaris, Lyosoma__________________________ 19 

Neritina _____________ 6, 9, 14, 16, 17,18, 19; pl. 3 

phillipsii, Turbo ____ -------------------------- 20 

Piper Formation_---------------------------- 11 

Pleurotomaria_ ----------------------- ______ 6, 12, 15 

borealis ______ ----------- __ ----------------- 13, 15 circumtrunca ____________________________ 9, 13,15 

rozete_ ----------------------- ------------ 15 

skidegatensis --------------------------- 12, 13,15 

subarenosa ________________ --------- ______ 12, 13 

sp. A_----------------------------------- 12 

sp. B ------------------------------------ 12 

sp ------------------------- 6, 8, 11, 12, 15; pl. 1 

spp __ ------------------------------------- 13 Pleurotomariacea ___________________________ 9, 13, 15 

Pleurotomariidae ___________________________ 9, 13,15 

powelli, Desmieria (Lyosoma)_________________ 17 

Lyosoma _________ 6, 8, 10, 11, 14, 16, 17, 18; pl. 2 

Neritina -------------------------------- 9, 16,17 

Otostoma (Lyosoma)______________________ 17 

Preservation of the fossils--------------------- 6 

Preuss Sandstone_____________________________ 11 

Procerithiidae ______________________________ 9, 14,20 

Procerithiinae ___________________________ --- _- 20 

Procerithium ___________________ 10, 11, 14, 20, 21; pl. 3 

michinhamptonense ----------------------- 13,14 

quinquegranosum ------------------------- 21 

tustum ______ ---------- ___________________ 12, 14 

sp ----------------------------- 6, 11, 13, 21; pl. 3 

spp __ --------------- ___ ______ _ ____ _ ______ 14 

Pseudomelaniacea _______________________ 9, 13, 14,21 

Pseudomelania _________ ____________________ 12,21, 22 

goodellL _____ ---------------------------- 9,14 

gresslyi_ ____ __________ -------- __ ---------- 21 

(Oonia) leymeriei__ _______________________ 12,13 

(Oonia) subglobosa________________________ 12 

sp __________________________ 6, 10, 11, 14, 21; pl. 3 

Pseudomelaniidae __________________________ 9, 14,21 

puligera, Nerita_______________________________ 19 

Purpurina ___ __________________________ -- -- _ __ 9 

cancellata _____________ -- _ ----------------- 11, 14 

elaborata _____________________ ------------ 12, 14 

hellona ________ --------------------------- 13,14 

sp ________________________________________ 12, 14 

Purpurinidae ________________ ----------------- 14 

pyramidata, Cloughtonia. _ ----------------- 10, 13,14 

Q 

quinquegranosum, Procerithium_______________ 21 

R Page 

Rhabdocolpus __ ----- _------------------ D6, 10, 20, 22 

scalariforme ____ ----------------------- ____ 21 

viriosus ______________ ________ 6, 10, 14, 21; pis. 3, 5 

sp ___ --- __________________________________ 11, 14 

Rierdon Formation___________________________ 11 

Rock Creek Member of the Fernie Shale_____ 12 

rozete, Pleurotomaria__________________________ 15 

rugosa, Patella __________________________ -----_ 15 

Symmetrocapulus ------------------------ 15 

s 

saharae, Teinostompsis------------------------ 15 

Sawtooth Formation_________________________ 11 

Scalaria liasinus. _ ---------------------------- 9 

scalariforme, Rhabdocolpus____________________ 21 

scalariformis, Melania________________________ 20 

sedgvici, Tornatellaea-------------------------- 13, 14 

Shel1kof Formation _________________ c __ ------- 13 

Skeneidae __ ------------- _____________ -------- 13 

skidegatensis, Pleurotomaria ________________ 12, 13,15 

Smackover Formation------------------------ 9 

squamosum, Lyosoma_________________________ 17 

stantoAptyriella (Nerinoides)__________________ 9 

ni, Delphinula____________________________ 9 

Metriomphalus .. _____ ------------ ________ 14 

Nerinella. ______________ -- ____ ------------ 9 

Nerinoides.----- ____ ---------------------- 14 

Stomatia bicarinata____________________________ 17 

ornatissima ____________ ___ -- __ ------------ 17 

Stratigraphic distribution._------------------ 7 Streptoneura ______________________________ 13, 14,15 

Strombacea _________________________________ -- 14 

subarenosa, Pleurotomaria _____________________ 12, 13 

subdesvoidyi, Cossmannea_____________________ 23 

subglobosa, Oonia. ____ ---- __ ---- __ ------------ 12, 14 

Pseudomelania (Oonia)___________________ 12 

subpyramidalis, Turbo._---------------------- 13 

sulcata, Ooliticia. _______ ---------------------- 20 

Swift Formation______________________________ 11 

Symmetrocapulidae __________________________ 13,15 

Symmetrocapulus_____________________________ 6,15 

corrugatus ________________________ 6, 13, 15; pl. 1 

rugosa .. ---------------------------------- 15 

T 

Talkeetna Formation------------------------- 12 

Teinostomopsis. ____ -------------------------- 15, 16 

saharae ______________ --------- _ ------------ 15 

SP---------------------------- 6, 10, 13, 15; pl. 1 

thompsonensis, Nerinea. __ -------------------- 12,14 

tindonensis, Ceritella _________________________ 10, 14 

Tornatellaea sedgvici__ _____ -------------------- 13,14 

Trachynerita _________ ------------------------- 9 

nodolirata _____________ ________ ------------ 14 

Trochacea----------------------------------- 9, 13, 15 

SP---------------------------------- 6, 16; pl. 1 Trochidae __________________ ------------------ 13 

Trochiform gastropods ____ -------------------- 10 

Trochus anglicus .. __________ -- ____ ------------ 15 

hinchmanensis ____________________ -------- 12, 13 

turbatric, Nerinea_____________________________ 9,14 

Turbinidae _____ _________ ---------------------- 9, 13 

Turbo beneclathratus __ ------------------------ 9,13 

ferniensis _____ ------------------------- ---- 12 

paskentaensis _______ ----------------------- 12 

phillipsii _____________________ -- --------- _ 20 

subpyramidalis _____ -------------- __ ------ 13 

Turriculale gastropods----------------------- 10,22 

Turritella burckhardti_________________________ 9,14 

Turritellidae _______________ ------------------ 9, 14 

Tuxedni Group _______________________ --------

Twelvemile Canyon Member of the Arapien 

Shale ___________ -_--_-------------

Twin Creek Limestone ______________________ _ 

Twist Gulch Member of the Arapien Shale_-

Tylostoma __ ----------------------------------

Tylostoma globosum ___ ------------------------

12 

1 

10 

22 

22 

Tylostoma SP------------------ 6, 10, 11, 14, 22; pl. 4 
INDEX D29 

V Page w Page X Page 

Vermetidae _________ ---------------- __ __ _ ___ _ _ D9 

Vermetus cornejoi_---- _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 9 

West Texas___________________________________ D9 

Western interior of United States_____________ 9 

williamsi, Globularia ________ ____ ------------ __ 14 

Xystrella ___ -------------------------------- D14, 21 

papillosa_ --------------- _ --------------- __ 9, 14 

vetustum, Procerithium ________________________ 12,14 Natica ____ -------- __ ------ ____ ------------ 9 y 

viriosus, Rhabdocolpus _____ 6, 10, 14, 21; pis. 3, 5 wyomingemis, Neritina_ ----------------- 9, 11, 14,19 Yakoun Formation __________________________ _ 12 

PLATES l-5 
PLATE 1 

FIGURES 1, 6, 8. Trochacea? sp. (p. D16) 

1. Apical view (X 5) of a specimen from loc. 26B. USGS 28456, USNM 144828. 

6. Oblique view (X 8) of a specimen from loc. 8a. USGS 19428, USNM 144832. 

8. Apical view (X 8) of a specimen from loc. 8a. USGS 19428, USNM 144833. 

2-4, 7. Teinostomopsis? sp. (p. D15) 

2. Composite reconstruction (X 8) of a specimen from the Carmel Formation of Utah. 

3. Front view (X 8) of a specimen from loc. 26B. USGS 28456, USNM 144829. 

4. Drawing of the basal view (X 6) of a specimen from loc. 26B. USGS 28456, USNM 144830. 

7. Apical view (X 5) of a specimen from loc. 26B. USGS 28456, USNM 144831. 

5. Ooliticia? sp. (p. D20) # 

Drawing (X 3) of a rubber squeeze of a fragmentary external mold from loc. 34a. USGS 28473, USNM 144847. 

9, 13. Pleurotomaria? sp. (p. D15) 

Basal and back views (natural size) of a specimen from loc. 33. USGS 16624, USNM 144826. 

10-12. Nododelphinula? sp. (p. D19) 

10, 12. Drawings of top (X 5) and back (X 4) views of a rubber cast of specimen from loc. 33. USGS 16624, 

USNM 144848. 

11. Drawing of an oblique view (X 5) of a worn specimen showing bicarinate whorls from loc. 39. USGS 28479, 

USNM 132637. 

14. Arnberleya? sp. (p. D20) 

View (X 3) of a rubber impression of part of a body whorl of an external mold from loc. 16. USGS 28470, USNM 

132639. 

15-17. Cylindrobullina? sp. (p. D24) 

15. Front view (X 10) of a specimen from the Twin Creek Limestone locality near Thistle, Utah. USGS 28458, 

USNM 132640. 

16. Front view (X 10) of a specimen from the same locality. USGS 28458, USNM 144849. 

17. Back view (X 10) of a specimen from the same locality. USGS 28458, USNM 144850. 

18-21. Neridomus? sp. (p. D19) 

Profile, apical, front, and back views (X 4) of a specimen from loc. 2. USGS 21448, USNM 144851. 

22-24. Symmetrocapulus? corrugatus Sohl, n. sp. (p. D15) 

Apical and side views (natural size) of the holotype from loc. 21. USGS 16202, USNM 144827. 
GEOLOGICAL SURVEY PROFESSIONAL PAPER 003-D P LATE 1 

X 5 

1 2 

X8 X 5 X8 

6 9 

7 8 

X5 

11 12 

10 

X3 

14 

22 23 24 

TROCHACEA?, TEINOSTOMOPSIS?, OOLITICIA?, PLEUROTOMARIA?, NODODELPHINULA'!, 

AMBERLEYA?, CYLINDROBULLINA?, NERJDOMUS?, AND SYMMETROCAPULUS? 
PLATE 2 

FIGURES 1-3, 7-10, 14. Lyosoma powelli White (p. D17) 

1- 3. Front, apical, and back views (X 2) of a silicified specimen, that retains (fig. 1) the median inner lip 

septum, from member B of the Twin Creek Limestone, Afton quadrangle, Wyoming. USGS 16036, 

USNM 144834. 

7-9, 14. Back, front, top, and side views (X 2) of the lectotype from mouth of Thistle Creek, Spanish 

Fork Canyon, Utah. USNM 144835. 

10. Top view of a syntype (X 2) from the same locality. USNM 144836. 

4-6. Lyosoma n. sp. (p. D17) 

Back, top, and front views (X 2) of a specimen mentioned by Stanton (1899, p. 630), from the Rierdon 

Formation on Fawn Creek, Yellowstone National Park, Mont. USNM 30591. 

11-13, 15-24. Lyosoma enoda Soh!, n. sp. (p. D18) 

11-13. Top, front, and back views (X 4) of a specimen from the cotype lot of Neritina phaseolaris from 

Salt Creek near Nephi, Utah. USNM 144837. 

15, 16, 19. Back, top, and profile views (X 3) of the holotype from Joe. 23. USGS 17412, USNM 144838. 

17, 20. Front and back views (X 4) of a specimen from the cotype lot of Neritina phaseolaris from Salt 

Creek, near Nephi, Utah. USNM 144839. 

18. Back view (X 2) of a worn specimen, showing two major color bands, from Joe. 25. USGS 24258; 

USNM 144840. 

21. Apical view (X 3) of a paratype from locality 23. USGS 17412, USNM 144841. 

22. Enlargement (X 3) of two specimens (shown in fig. 24) from Joe. 4. USGS 21446, USNM 144842. 

23. View (natural size) of an incomplete specimen, showing two strong color bands, the "Lower Sundance 

Formation" of Wyoming. USGS 20369, USNM 144843. 

24. View (natural size) of a small hand specimen, showing association of Lyosoma enoda with coarse rounded 

shell and limestone pebbles, from Joe. 4. USGS 21446, USNM 144842. 
GEOLOGICAL SURVEY PROFESSIONAL PAPER 503- D P LATE 2 

10 

"' 

:: 11t.: 

22 23 24 

LYOSOMA 
PLATE 3 

FIGURES 1-6. Rhabdocolpus viriosus Soh!, n. sp. (p. D21) 

1. Back view (X 8) of a paratype, showing alinement of transverse ribs, from the Twin Creek Limestone, near 

Thistle, Utah. USGS 28458, USNM 144852. 

2. Drawing of a front view (X 14) of a paratype from loc. 26B. USGS 28456, USNM 144853. 

3. Drawing (X 5) of a worn paratype, showing development of spiral sculpture, from loc. 33. USGS 16624, 

USNM 144854. 

4. Back view (X 10) of a worn paratype, showing alinement of ribs, from loc. 26B. USGS 28456, USNM 144855. 

5. Back view (X 5) of a specimen from the Twin Creek Limestone near Thistle, Utah . USGS 28458, USNM 

144846. 

6. Back view (X 8) of the holotype, showing coronate ribs of the body whorl, from the Twin Creek Limestone near 

Thistle, Utah. USGS 28458, USNM 144856. 

7. Pseudomelania? sp. (p. D21) 

Back view (X 4) of a specimen from Joe. 26A. USGS 25669, USNM 144857. 

8-11. Procerithium? sp. (p. D21) 

8. Front view (X 5) of a specimen from Joe. 26B. USGS 28456, USNM 144858. 

9. Drawing (X 7) of a worn specimen from Joe. 26B. USGS 28456, USNM 144859. 

10. Back view (X 6) of a specimen from loc. 26B. USGS 28456, USNM 144860. 

11. Front view (X 6) of a specimen from Joe. 26B. USGS 28456, USNM 144861. 

12- 21. Neritina? phaseolaris White (p. D19) 

12, 14, 15. Top, back, and profile views (X 4) of a syntype from Salt Creek, near Nephi, Utah. USNM 8587. 

13. Top view (X 2) of a specimen, showing color markings from the Carmel Formation at Joe. 25. USGS 24258, 

USNM 132843. 

16, 17. Back and top views (X 4) of a specimen from the Carmel Formation at Joe. 32. USGS 24258, USNM 

144844. 

18-20. Top, front, and profile views (X 4) of the lectotype from Salt Creek, near Nephi, Utah . USNM 144845. 

21. Back view (X 4) of a specimen from the Carmel Formation at Joe. 25. USGS 24258, USNM 144846. 
GEOLOGICAL SU HVEY PROFESSIONAL PAPER 503- D PLATE 3 

4 5 

X8 X 14 X5 

6 

1 2 

3 

X4 X6 X5 

7 X7 10 8 

9 

X6 

11 

X2 

12 13 

16 

14 15 

RHABDOCOLPUS, PSEUDOMELANIA?, PROCERITHIUM? AND NERITINA? 
PLATE 4 

FIGURES 1-8. Cossmannea imlayi Sohl, n. sp. (p. D23) 

1. Back view (natural size) of a paratype from loc. 31C. USGS 28468, USNM 144861. 

2, 3. Front and back views (natural size) of a paratype from loc. 31C. USGS 28468, USNM 144862. 

4. Front view (natural size) of a paratype from loc. 31C. USGS 28468, USNM 144863. 

5. Back view (natural size) of the holotype from loc. 31C. USGS 28468, USNM 144864. 

6. Back view (natural size) of a paratype from loc. 31C. USGS 28468, USNM 144865. 

7. Polished longitudinal section (X 1)r2) of a paratype from loc. 31C. USGS 28468, USNM 144866. 

8. Polished longitudinal section (X 1~) of a paratype from loc. 31C. USGS 28468, USNM 144867. 

9, 17, 18. Cossmannea? kanabensis Sohl, n. sp. (p. D24) 

9. View (X 3) of a paratype, showing whorl cross section, from loc. 34A. USGS 28473, USNM 144868. 

17. Back view (X 3) of the holotype from loc. 34A. USGS 28473, USNM 144869. 

18. Front view (X 3) of a paratype from loc. 40. USGS 17351, USNM 144870. 

10-15. Globularia? sp. (p. D22) 

10. Apical view (X 2) of a specimen from loc. 38B. USGS 28495, USNM 144871. 

11, 12. Front and back view (X 2) of a specimen from loc. 31B. USGS 26307, USNM 144872. 

13. Back view (X 2) of a specimen from loc. 15A. USGS 28463, USNM 144874. 

14. Front view (X 2) of a specimen from loc. 38B. USGS 28495, USNM 144873. 

15. Front view (X 2) of a specimen from loc. 15A. USGS 28463, USNM 144875. 

16, 19. Tylostoma? sp. (p. D22) 

16. Back view (natural size) of a specimen from loc. 15A. USGS 28463, USNM 132641. 

19. Back view (natural size) of a specimen from loc. 17B. USGS 25684, USNM 144844. 
GEOLOGICAL SURVEY PROFESSIONAL PAPER 503-D PLATE 4 

2 3 

1 

8 

5 

X2 

9 

X3 

17 18 19 

COSSMANNEA, GLOBULAR/A?, TYLOSTOMA? 
PLATE 5 

FIGURES 1- 3. Views of weathered limestone surfaces from the Carmel Formation and 

Twin Creek Limestone showing concentrations of small gastropod species. 

1. Specimens (X 2) of Cylindrobullina? sp. and an indeterminate turriculate snail from loc. 7B. USGS 18671, USNM 144845. 

2. Concentration of turriculate gastropods (X 2) from mouth of Thistle 

Creek. Surface of specimens too worn for positive identification. 

USNM 19965. 

3. Enlarged view (X 5) of a section of a hand sample, showing intermixture of Cylindrobullina? sp., Rhabdocolpus viriosus, indeterminate gastropods, and crinoid debris, from the Twin Creek Limestone near Thistle, Utah. USGS 28458, USNM 144846. 
GEOLOGICAL SU HVEY PROFESSIONAL PAPER 503-D PLATE 5 

3 

SPECIMENS OF CARMEL LIMESTONE