Shorter Contributions 

to Paleontology, 

1979

GEOLOGICAL SURVEY PROFESSIONAL JPAPEK 1125-A-D

Shorter Contributions 

to Paleontology, 

1979

Western Hemisphere Cretaceous Itieriidae Gastropods 

By HEINZ A. KOLLMANN and NORMAN F. SOHL

Ostracode Biostratigraphy of Pliocene and Pleistocene Deposits 

of the Cape Fear Arch Region, North and South Carolina

By THOMAS M. CRONIN and JOSEPH E. HAZEL

Miocene Mollusks of the Topsy Formation, Lituya District, 

Gulf of Alaska Tertiary Province, Alaska

By LOUIE MARINCOVICH, JR.

Variability in Trithyrodinium Drugg 1967 

By FRED E. MAY and DON G. BENSON, JR.

GEOLOGICAL SURVEY PROFESSIONAL PAPER 1125-A-D

UNITED STATES GOVERNMENT PRINTING OFFICE, WASHINGTON : 1980
UNITED STATES DEPARTMENT OF THE INTERIOR 

CECIL D. ANDRUS, Secretary

GEOLOGICAL SURVEY 

H. William Menard, Director

Library of Congress catalog-card No. 79-600193

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

Washington, D.C. 20402 

Stock Number 024-001-03248-1
CONTENTS

[Letters designate the chapters]

(A) Western Hemisphere Cretaceous Itieriidae Gastropods, by Heinz A. Kollmann 

and Norman F. Sohl

(B) Ostracode Biostratigraphy of Pliocene and Pleistocene Deposits of the Cape 

Fear Arch Region, North and South Carolina, by Thomas M. Cronin and 

Joseph E. Hazel

(C) Miocene Mollusks of the Topsy Formation, Lituya District, Gulf of Alaska 

Tertiary Province, Alaska, by Louie Marincovich, Jr.

(D) Variability in Trithyrodinium Drugg 1967, by Fred E. May and Don G. Benson, Jr.
CONVERSION FACTORS

Metric unit Inch-Pound equivalent

Length

millimeter (mm) 

meter (m) 

kilometer (km)

= 0.03937 inch (in) 

= 3.28 feet (ft) 

= .62 mile (mi)

Area

square meter (m2 ) 

square kilometer (km2 ) 

hectare (ha)

= 10.76 square feet (ft2 ) 

= .386 square mile (mi2 ) 

= 2.47 acres

Volume

cubic centimeter (cm3 ) 

liter (L) 

cubic meter (m3 ) 

cubic meter 

cubic hectometer (hm3 ) 

liter 

liter 

liter 

cubic meter

cubic meter

= 0.061 cubic inch (in3 ) 

= 61.03 cubic inches 

= 35.31 cubic feet (ft3 ) 

= .00081 acre-foot (acre-ft) 

= 810.7 acre-feet 

= 2.113 pints (pt) 

= 1.06 quarts (qt) 

= .26 gallon (gal) 

= .00026 million gallons (Mgal or 

10a gal) 

= 6.290 barrels (bbl) (1 bbl = 42 gal)

Weight

gram (g) 

gram 

metric tons (t) 

metric tons

= 0.035 ounce, avoirdupois (oz avdp) 

= .0022 pound, avoirdupois (Ib avdp) 

= 1.102 tons, short (2,000 Ib) 

= 0.9842 ton, long (2,240 Ib)

Specific combinations

kilogram per square 

centimeter (kg/cm2 ) 

kilogram per square 

centimeter 

cubic meter per second (m;! /s)

 0.96 atmosphere (atm)

 .98 bar (0.9869 atm) 

= 35.3 cubic feet per second (ft3/s)

Metric unit

Specific

liter per second (L/s) 

cubic meter per second 

per square kilometer 

[(m3/s)/km2 ] 

meter per day (m/d)

meter per kilometer 

(m/km) 

kilometer per hour 

(km/li) 

meter per second (m/s) 

meter squared per day 

(m3/d) 

cubic meter per second 

(m«/s) 

cubic meter per minute 

(m3/min)

liter per second (L/s) 

liter per second per 

meter [(L/s)/mJ 

kilometer per hour 

(km/h) 

meter per second (m/s) 

gram per cubic 

centimeter (g/cm3 ) 

gram per square 

centimeter (g/cm2 ) 

gram per square 

centimeter

Inch-Pound equivalent

combinations Continued

= .0353 cubic foot per second 

= 91.47 cubic feet per second per 

square mile [(ft3/s)/mi2 ]

= 3.28 feet per day (hydraulic 

conductivity) (ft/d) 

= 5.28 feet per mile (ft/mi)

 .9113 foot per second (ft/s)

= 3.28 feet per second 

= 10.764 feet squared per day (ft2/d) 

( transmissivity ) 

 22.826 million gallons per day 

(Mgal/d) 

= 264.2 gallons per minute (gal/min)

= 15.85 gallons per minute 

= 4.83 gallons per minute per foot 

[(gal/min) /ft] 

 .62 mile per hour (mi/h)

 2.237 miles per hour

= 62.43 pounds per cubic foot (lb/ft3 ) 

= 2.048 pounds per square foot (lb/ft2 ) 

= .0142 pound per square inch (lb/in2 )

Temperature

degree Celsius (°C) 

degrees Celsius 

(temperature)

= 1.8 degrees Fahrenheit (°F) 

= [(l.Sx°C)+32] degrees Fahrenheit
Western Hemisphere Cretaceous 

Itieriidae Gastropods

By HEINZ A. KOLLMANN and NORMAN F. SOHL

SHORTER CONTRIBUTIONS TO PALEONTOLOGY, 1979

GEOLOGICAL SURVEY PROFESSIONAL PAPER 1125-A

CONTENTS

	Page

Abstract ___________________________________________________ Dl

Introduction _____________________________________________ 1

Observations ____________________________________________ 2

Taxonomic considerations ___________________________________________ 4

Conclusions ____________________________________________ 6

References cited __________________________________________ 6

ILLUSTRATIONS

Page

FIGURE 1. Map of the northern Coastal Plain, showing collecting areas at Round Bay, Md., and Poricy Brook,

N.J. _____________________________________________________________________________________ Dl

2. Specimens of Trithyrodinium cf. T. fragile collected from Poricy Brook, N.J., showing gradation in the

morphologic variability of anterior intercalary paraplates ____________________________ 2

3. Sketches of endopercular pieces from specimens of Trithyrodinium cf. T. fragile collected from Poricy

Brook, N.J. __________________________________________________________ 3

4. Drawings showing variation in endoarcheopyle outline for trithyrodinioid cysts discussed in this report. _ 4

5. Photomicrographs and sketches of specimens of Trithyrodinium striatum Benson, 1976, showing variability in the morphology of endopercular pieces and in the outline of endoarcheopyle _______________ 5

in

SHORTER CONTRIBUTIONS TO PALEONTOLOGY, 1979

WESTERN HEMISPHERE CRETACEOUS ITIERIIDAE GASTROPODS

By HEINZ A. KOLLMANN x and NORMAN F. SOHL

ABSTRACT

The presence of representatives of the itieriid (Nerinaecea) gastropod genera Vernedia and Sogdianella in Cretaceous rocks of the Western Hemisphere is reported for the 

first time. In addition, Pervviella Olsson is transferred from 

the Actaeonellacea because it possesses an anterior canal, 

thus precluding the cephalic shield characteristic of cephalaspidean Opisthobranchia. The occurrence of Peruviella gerthi 

Olsson in the area from Peru to Brazil and thence to Angola 

suggests a marginal Tethyan distribution pattern, whereas 

the other species discussed are more typically distributed 

through the main central Tethys biotic realm.

INTRODUCTION

Representatives of the nerineacean family Itieriidae occur widely in the shallow warm-water faunas 

of the Tethyan province of most areas during Middle Jurassic to Late Cretaceous time. Of all the genera assigned to the Itieriidae, only the genus Phaneroptyxis has previously been recognized from the 

Western Hemisphere. Records of this genus are 

rare, resting only on Phaneroptyxis anguillana 

(Castillo and Barcena) of Cserna (1956) from the 

Lower Cretaceous of southern Mexico and on Phaneroptyxis? angulata Imlay (1941) from the subsurface Smackover Formation (Jurassic) of Arkansas. 

Aguilera (1906) cited the additional nomen nudum 

Phaneroptyxis teloloapensis from the Cretaceous of 

Mexico. One major reason for the dearth of any 

significant record for members of this family in this 

hemisphere is the superficial external morphologic 

resemblance many species bear to members of the 

Actaeonellacea. Thus, a number of the species we 

discuss here were originally described under Actaeonella, a group belonging to an entirely different 

order, the cephalaspidean Opisthobranchia.

1 Geologisch-Palaeontologische 

Vienna, Austria.

Abteilung Naturhistorisches Museum,

ACKNOWLEDGMENTS

We acknowledge the aid of Katherine Van Winkle 

Palmer for the loan of A. A. Olsson types from Peru 

housed in the collections of the Paleontological Research Institute, Ithaca, N.Y. Keith Young and 

Christopher Burden are due our thanks for the loan 

of collections from the Cretaceous of Texas housed 

at the Texas Memorial Museum at Austin. Annie 

Dhondt of the Royal Institute of Natural Sciences, 

Brussels, Belgium, aided in translation of pertinent 

Russian literature.

The following abbreviations are used for collections housed at the various institutions: USNM, 

National Museum of Natural History, Washington, 

D.C.; USGS, United States Geological Survey, 

Washington, D.C.; UT and UT2, University of 

Texas, Austin, Tex; PRI, Paleontological Research 

Institute, Ithaca, N.Y.

Under the sections headed "Measurements" the 

following symbols are used: H = Height measured 

parallel to the shell axis, MD = Maximum diameter 

measured perpendicular to the shell axis, and PA = 

Pleural angle.

NOTES ON PALEOBIOGEOGRAPHY

The three itieriid genera Vernedia, Sogdianella, 

and Peruviella, discussed here, had somewhat different patterns of distribution. In all patterns, however, they are associates of either shallow, warmwater Tethyan or marginal Tethyan faunas. The 

most widely spread of the genera, Vernedia (fig. 1) 

occurs from Mexico across Europe and the Middle 

East to India, and possibly to Borneo and Japan in 

a pattern closely approximating that for orbitolinid 

formaminifers or rudist bivalves. Within this range, 

however, some separation of species groups occurs 

that may reflect provincial separation. As discussed 

in the systematics part of this paper, the Mexican

Ai
A2 SHORTER CONTRIBUTIONS TO PALEONTOLOGY, 1979
WESTERN HEMISPHERE CRETACEOUS ITIERIIDAE GASTROPODS A3

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A4 SHORTER CONTRIBUTIONS TO PALEONTOLOGY, 1979

and south Indian species are morphologically closer 

akin to each other than to the European and Middle 

Eastern species. As has been pointed out by several 

authors, Caribbean rudist bivalves show considerable differentiation from their coeval Mediterranean 

relatives but are similar to forms found on Cretaceous Pacific atolls. The amount of difference in the 

Vernedia species, however, is not as great as in the 

rudist examples. In Vernedia, this is a species group 

level difference as opposed to the generic level difference among rudists. Although Sogdianella is less 

common and less diverse than Vernedia, the distribution of Sogdianella roughly parallels that of Vernedia (figs. 1 and 2).

The genus Peruviella shows a different distribution pattern (fig. 2). With the exception of occurrences associated with the rudist framework facies 

in the Albian of Texas, its presence in the Albian 

of Peru, Brazil, and western Africa is paralleled by 

other Cretaceous molluscan genera. For example, 

the arcoid bivalve genus Pseudocucullaea possessed 

a similar distribution (Darteville and Freneix, 1957, 

p. 42). This pattern of distribution may also be seen 

in the marginal marine or brackish-freshwater transition gastropods of the Thiariidae. The Thiariidae 

maintain such a dispersal pattern well into Tertiary 

time but later split into endemic centers. In essence, 

the pattern appears to be best described as southern 

submarginal or marginal Tethyan as opposed to the 

more truly Tethyan occurrence of Vernedia and 

Sogdianella.

SYSTEMATIC PALEONTOLOGY

Order ENTOMOTAENEATA Cossmann

Superfamily NERINAECEA 

Family 1T1ERI1DAE Cossman, 1896

The family Itieriidae is widely represented and is 

diverse in the Cretaceous deposits of Europe, the 

Middle East, and Transcaucasia. In the Western 

Hemisphere, however, occurrences are sporadic. 

Aside from the two species of Phaneroptyxis noted 

before, only five species assigned to three genera 

are presently known. These are as follows:

Vernedia freisi, n. sp. 

Peruviella gerthi Olsson 

Peruviella dolia (Roomer) 

Sogdianella peruviana (Olsson) 

Sogdianella subcylindrica n. sp.

The presence of these species in rocks ranging in 

age from Albian to Maestrichtian and in geographic 

extent from Peru to Texas (figs. 1 and 2) suggests 

that this record reflects only minimal potential diversity. In part, it may reflect the rather poorly 

known or poorly represented Cenomanian to Coniacian near shore deposits, especially in the Caribbean 

region.

The species herein assigned to Vernedia would 

previously have been considered as belonging to 

Itruvia. The genus Itruvia was considered closely related to Itieria by Stoliczka (1868) and was later 

placed within the family Itieriidae by both Cossmann 

(1896) and Wenz (1938-44). As we indicate in the 

discussion of Vernedia, the type species of Itruvia 

appears to be a cerithiid. Both Peruviella and Sogdianella were considered as Actaeonellidae by their 

describers. Zilch (1959-60) followed Olsson (1934) 

in accepting the systematic position of Peruviella 

within the "Aceaeonellinae." The related genus Sogdianella was later described by Djalilov (1972). The 

reason these two genera are considered herein as 

Itieriidae is primarily the form of the whorl base. 

Olsson (1934) mentioned in the description of Peruviella gerthi, the type species, that the base of the 

body whorl ends in a small projecting beak. This 

morphologic feature is a fragile part of the shell 

and is usually broken off, but its shape can be deduced from the form of the whorls and columella in 

cut section. The columella is partly hollow, and it 

has a central pillar with concave sides. This pillar 

was originally the anterior canal of the whorls and 

was, °,t a later growth stage, filled with shell 

material.

The pillar is very distinct in Peruviella but not in 

Sogdianella, where it is short and only slightly concave at the sides. Thus, in Sogdianella, the columella 

is either solid or only slightly hollow. The description 

of Sogdianella on following pages demonstrates its 

close similarity to Peruviella and its differences from 

Actaeonella, and it is, therefore, reassigned to the 

Itieriidae.

Although the Cenomanian genus Eotrochactaeon 

Hacobjan, 1972, does not occur in the Western 

Hemisphere, its systematic placement parallels the 

case for Peruviella. Hacobjan (1972) placed Eotrochactaeon within the "Trochactaeonidae," but, like 

the genera discussed before, it possesses the hollow 

columella and central pillar of the Itieriidae. Unlike Peruviella and Sogdianella, however, it is not 

involute but has a short spire. Hacobjan (1972) defined Eotrochactaeon as follows: "Shell large, oval, 

consisting mainly of the last whorl; spire short, 

sometimes hardly projecting or almost invisible; 

whorls moderately convex, with an inclined sutural 

ramp in the upper portion; aperture elongate, semilunate, broad, gradually and evenly tapering towards
WESTERN HEMISPHERE CRETACEOUS ITIERIIDAE GASTROPODS A5

the base; walls very thick, smooth, a little arched 

on top; columella with three plaits, vestiges of a 

narrow almost closed umbilicus."

On the basis of the characters of shell form and 

aperture, the Acteonellidae are considered cephalaspidian Opisthobranchia gastropods. Any shell that 

possesses an anterior canal would not be amenable to 

placement in the family, as the possession of such a 

feature contravenes the possession of the characteristic cephalic shield. Thus, the demonstrated presence of an anterior canal in both Peruviella and 

Eotrochactaeon cannot be considered an example of 

character homeomorphy, and it supports their exclusion from the Actaeonellidae and placement in the 

Itieriidae. The placement of Sogdianella in the 

Itieriidae, however, rests on the less strong basis of 

its similarity to Peruviella.

Genus Vernedia Mazeran, 1912

Type species.—Vernedia laurenti Mazeran, 1912, 

by original designation.

Discussion.—Douville (1921), Wenz (1940, p. 

829), and subsequent workers have considered Vernedia Mazeran as a synonym of Itruvia Stoliczka 

(1867). Stoliczka did not designate a type species 

but listed several species as being representative for 

the genus, among them Pyramidella canaliculata 

d'Orbigny. This species was subsequently designated 

by Cossmann (1896) as the type species of Itruvia.

Mazeran (1912) proposed the generic name Vernedia and argued that the type species of Itruvia, as 

used by both d'Orbigny (1843) and Cossmann, comprised two different species of gastropods. The specimens from the upper Turonian of Uchaux, France, 

that have a smooth concave columella and no interior 

plication were described by Mazeran as Vernedia 

canaliculata (d'Orbigny). The other material 

(d'Orbigny, 1843, pi. 164, figs. 4, 5), which was described originally from the French Province of 

Gard, was included by Mazeran in his new species 

Vernedia laurenti. This species is characterized by 

both a columellar plait and a parietal plait, according to Mazeran's figures. Mazeran explicity designated laurenti as type species of Vernedia. Although 

Mazeran's total suppression of the name Itruvia is 

not correct in a nomenclatorial sense, we agree with 

him that "Pyramidella canaliculata d'Orbigny" included two different gastropod taxa. Thus, Mazeran's 

separation and description of one of these species as 

Vernedia laurenti and the type of his new genus 

must be viewed as valid. As Douville (1921) pointed 

out, even though d'Orbigny's original definition of 

Pyramidella canaliculata, refers primarily to the

specimens from Gard, Mazeran's discussions restrict 

the name to the specimens that came from Uuchaux, 

France. These specimens thus form the basis for 

understanding P. canaliculata, the type species of 

Itruvia. We agree with Douville that the type species, 

and, therefore, the genus Itruvia is closely related to 

the cerithiid genus Campanile. In summary, Vernedia cannot be considered as a junior synonym of 

Itruvia. Thus, all species from Europe and Asia that 

have been hitherto incorporated within Itruvia, except for the forms identical with /. canaliculata from 

Uchaux, should be assigned to Vernedia.

The oldest species of Vernedia occur in rocks of 

Cenomanian Age. The genus is most widespread and 

diverse in rocks of Cenomanian and Turonian Age 

(fig. 1), but a few are to be found as late as the Campanian and Maestrichtian deposits of Southern India 

(Stoliczka, 1867).

The only species of Vernedia known in the Western Hemisphere is V. freisi, described below, from 

Mexico. Its closest affinities are with V. globoides 

(Stoliczka) from southern India rather than with 

the European and Transcaucasian species discussed 

below.

The following species differ from Vernedia freisi 

in possessing a longer, thinner pillar, but all belong 

in Vernedia and are here transferred: 

Itruvia gigantea Ptselintsev, 1953 

armenica Ptselintsev, 1953 

subornata Ptselintsev, 1953 

fergenensis Ptselintsev, 1953 

armenica ornata Ptselintsev, 1953 

caucasica Ptselintsev, 1953 

angusta Ptselintsev, 1953 

subcarinata Ptselintsev, 1953 

cycloidea Ptselintsev, 1953 

subcycloidea Ptselintsev, 1953 

dolioliformis Ptselintsev, 1953 

cerithiformis Ptselintsev, 1953 

stephanovi Ptselintsev, 1954 

ovalis Ptselintsev, 1953

The above listed species come from lower Turonian deposits of the Transcaucasia. When considering the amount of variation in proportional height 

of spire and resulting relative obseity of the body 

whorl shown by specimens of V. freisi, one may 

doubt the advisability of proposing so many species 

for forms from a narrow stratigraphic interval in a 

single region. Without having seen Ptselintsev's 

original material, we believe that the above listed 

species consist of only two groups. We feel that 

each group probably deserves no more than species 

rank. These are as follows:
A6 SHORTER CONTRIBUTIONS TO PALEONTOLOGY, 1979

1. Vernedia cydoidea group. Oviform to globular 

shells; base concave to flat; columella inclined; 

parietal ridge rounded and low. The group consists of the species Itruvia cydoides, I. subcydoides, I. caucasica, and I. gigantea. In addition, Itruvia abbreviata (Phillippi) morfa, A, B, 

C of Lupu, 1966, belong to the same group. Representatives of this group have also been found in 

Austria (Kollmann, 1968).

2. Vernedia armenica group. High-spired Vernedia 

with strong prosocline, transverse ribs, and rows 

of nodes on the upper part of the whorls; base 

tapering, columella high, almost vertical, with a 

rather weak plait; parietal ridge much stronger 

than in the Vernedia cydoidea group. The 

Vernedia armenica group consists of /. armenica, 

I. subornata, I. fergenensis, I armenica ornata, 

I. subcanaliculata, I. angusta, I. cerithiiformis, 

I. stephanovi, and I. ovalis.

The middle Cenomanian species that Rahman 

(1967) described from Hoelzelsau in Tyrol, Austria, 

all belong to the V. armenica group. The transverse 

ribs are dissolved or pinched into a variable number of nodes. All the forms described by Rahman 

were found at the same stratigraphic horizon in the 

same outcrop. They do not differ significantly in 

apertural characters or in columellar and parietal 

structures and probably belong, therefore, to the 

same species.

Vernedia abbreviata (Phillippi), 1851, is high 

spired and has a more or less convex last whorl. 

The illustration of that species provided by Lupu 

(1966) and Stoliczka (1868) shows that the parietal 

ridge is prominent and similar to the other highspired Vernedia mentioned above. The outer shell 

surface is smooth.

Vernedia globoides (Stoliczka) (1868) from the 

Arrialoor group (Campanian and Maestrichtian) of 

Comparapolliam in the Trichinopoly district in 

southern India shows a remarkable similarity to V. 

freisi if figure 1, plate 14, of Stoliczka is correctly 

drawn. It is subcyclindrical, the columella is concave 

externally and twisted outwards in its lower part. 

As the concave part is much higher here than in the 

aperture, where obviously a columellar lip with a 

plait is present, we may conclude that the concave 

side of the pillar is exposed. Compared with Vernedia freisi from Mexico, the last whorl of the specimen of V. globoides figured by Stoliczka is proportionally higher, and the maximum diameter is not as 

high.

80

70

60

50

40

30 40 

MAXIMUM DIAMETER, IN MILLIMETERS

50

FIGURE 3. Relationship of height and 

maximum diameter among specimens 

of Vernedia freisi Kollmann and Sohl.

Vernedia freisi Kollmann and Sohl, n. sp.

Figures 4 b, c, 5 a-e.

Diagnosis.—A Vernedia with a thick, stout, columellar pillar bearing convex sides.

Description.—Globose shells of medium size; maximum diameter 60-70 percent of total height; spire 

high, more than eight whorls, sides concave to 

slightly convex; whorls with narrow inclined subsutural ramp. Body whorl convex, with a depression

FIGURE 4. Camera lucida drawings of axial sections of:

a. Sogdianella aff. S. peruviana (Olsson) (X 2.5) 

from the Actaeonella limestone. Cerro Negro, 

Paita region, Peru (USGS 31452; USNM 25304). 

b, c. Vernedia freisi Kollmann and Sohl, n. sp. (x 1.3 

and 1.5), para types from near Armeria, State of 

Colima, Mexico (USGS 26391; USNM 251301 

and 251300).

d. Peruviella gerthi Olsson (x 1.3), from Pananga 

Formation, Pan de Azucar, western foothills of 

the Amotape Mountains, near Talara, Peru 

(USGS 27061; USNM 251305).

e. Peruviella dolium (Roemer) (x 1), from the Lower 

Cretaceous of Texas (UT2 1030).

/. Peruviella dolium (Roemer) (x 1.6) from Flat 

Mesa 6.4 km north of Sierra Blanca, El Paso 

County, Tex. (USGS 1809; USNM 251307).

g. Peruviella dolium (Roemer) (X 1), from the Finlay Mountains, Hudspeth County, Tex. (USGS 

1909; USNM 251309).
WESTERN HEMISPHERE CRETACEOUS ITIERIIDAE GASTROPODS A7
A8 SHORTER CONTRIBUTIONS TO PALEONTOLOGY, 1979
WESTERN HEMISPHERE CRETACEOUS ITIERIIDAE GASTROPODS A9

of variable strength in the middle, and faint strongly inclined prosocline growth lines. Aperture proportionally short, scimitar shaped, lower part considerably broader than upper part. Columella short 

with one plait, which is obliquely bent upward; 

columella above and below plait concave; weak 

parietal thickening in middle of parietal lip is broad 

but flat; central pillar of columella very thick and 

stout, lower end broadened so that pillar has concave sides; columella between concavity of pillar and 

adjoining columellar lip hollow; whorl base strongly convex or rounded; columella decreases regularly in length at aperture and together with outer lip 

forms a beaklike process at the base.

Measurements (fig. 3). Holotype—H, 44 mm; 

MD, 36 mm.

Paratypes—H, 39.5-58.7 mm; MD, 25.5-36.6 mm; 

PA, 50°-70°.

Discussion.—As indicated in the discussion of the 

genus, Vernedia freisi differs from all European species with which it could be compared by having a 

thick columellar pillar having convex sides. This 

feature indicates a dextral twisting of the apertural 

canal.

FIGURE 5. Vernedia freisi Kollmann and Sohl and Peruviella

gerthi Olsson. 

a-e. Vernedia freisi Kollmann and Sohl, n. sp.

a. Back view (x 1) of a paratype (USGS 26391; 

USNM 251298). Specimens from near Armeria, 

State of Colima, Mexico.

b. Back view (x 1) of a paratype with an especially globose body whorl (USGS 26391; USNM 

251299). 

c. Front view (x 1) of a paratype (USGS 26391;

USNM 251297). 

d. Front view (X 1) of the holotype (USGS 26391;

USNM 251295).

e. Back view (x 1) of a paratype possessing an exceptionally high spire (USGS 26391; USNM 

251296). 

f—k. Peruviella gerthi Olsson

/, g. Back and front views (X 0.8) of a paratype from 

the Pananga limestone, Pan de Azucar, Amotape 

region, Peru (Paleontological Research Institute, Ithaca, N.Y.)

h, k. Apical and front views (X 1) of a specimen from 

the Pananga limestone, Pan de Azucar, Amotape 

foothills of the Amotape Mountains near Talora, 

Peru (USGS 27061; USNM 251306). 

i. Axial section (x 1.5) of a specimen from the 

Pananga Formation, Pan de Azucar, western 

foothills of the Amotape Mountains near Talara, 

j. Axial section (X 2) of the holotype showing 

whorl shape and internal features; locality same 

as for figures / and g (Paleontological Research 

Institute, Ithaca, N.Y.).

Among the 24 specimens available for study, variation in proportional shape is great. This is amply 

demonstrated in the plot of height against maximum 

diameter measurements for the best preserved specimens presented in figure 3. Equally great variation 

in pleural angle is seen not only between specimens 

but between individual specimens of changing 

growth stages. Some specimens, such as that illustrated in figure 4c, possess a convex spire profile; 

others (fig. 5e) have a rather evenly tapering spire. 

Similarly, the profile of the body whorl may be well 

rounded (fig. 56) to medially flattened. All available 

specimens come from the same bed, and there is no 

reason to believe that the morphologic types present 

reflect more than intraspecific variation.

The species is named in honor of the original collector of the material Carl Freis, Jr., formerly of the 

U.S. Geological Survey.

Occurrence.— (USGS 26391). Road cut on 

Colima-Manzanillo highway, at east edge of village 

of Armeria, lat 18°56' N. and long 103°58' W., State 

of Colima, Mexico.

Age.—late Cenomanian or early Turonian.

Types.—Kolotype, USNM 251295. Paratypes, 

USNM 251296-251301.

Genus Sogdianella Djalilov, 1972

Type species.—Actaeonella supernata Ptselintsev, 

1953, by original designation.

Diagnosis (from Djalilov, 1972). "Shell of medium 

to small size, ovate to cylindrical; generally it resembles a cylinder with attached cones at both ends,; 

upper extremity trending toward a perforate condition ; spire partly or completely involute."

Discussion.—Ptselintsev's (1953) figures of the 

type species show some other morphologic features 

that seem to us important for the definition of the 

genus:

Whorls very narrow and only slightly widened in 

the lower part of the shell. Columella strongly inclined toward axis at lower end and bearing three 

plaits; columella below plaits strongly concave; short 

pillar within; columella having concave sides that 

indicate slight basal prolongation of whorls; often 

with a thin hollow space between pillar and adjoining part of the columella of next whorl.

Sognianella zekelii (Kollmann, 1965) was originally described as an Actaeonella and later correctly included by Djalilov (1972) in his new genus. In 

addition to the generic features we describe from the 

type species, paratypes of Sogdianella zekelii from 

the Upper Cretaceous of Kaiserhaus, northern Tyrol, 

Austria, show the principal constructional features
A10 SHORTER CONTRIBUTIONS TO PALEONTOLOGY, 1979

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' ' f f^lSSft!^ "-,v?uT*¥ «v,;~'" ;%"j.

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< ,

: '*^#3£&gk& ^

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WESTERN HEMISPHERE CRETACEOUS ITIERIIDAE GASTROPODS All

of the posterior exhalant siphon; namely, the 

growth lines, which are orthocline throughout most 

of the shell, are curved backward in the uppermost 

immediate subsutural part. The cut sections show 

that the first-formed pants of the outer and inner 

walls of the whorls are secondarily thickened in the 

upper part of the aperture, which thus become narrowed considerably. Between this point and the suture, the whorls again increase in width and widen 

interiorly. The whole structure is then filled by later 

shell layers. The exhalant siphon is, therefore, a 

combination of a notch as indicated by backcurving 

sinused growth lines and a funnellike structure. It 

opens on top of the shell and is more or less twisted 

to one side. In large specimens, this siphon opens 

into the apical perforation.

Actaeonella has a shell with convex sides, the 

whorls are broader interiorly than in Sogdianella, 

and the columella has more or less parallel sides and 

is solid. In addition, the axis above the shell center 

is solid, and the whorls do not join together loosely 

as in Sogdianella. In Actaeonella, the posterior extension of the aperture opens on top, but, unlike 

Sogdianella, it is not twisted to the side and there is 

no notch.

FIGURE 6.—Sogdianella subcylindrica Kollmann and Sohl, 

n. sp.; Sogdianella peruviana (Olsson) ; and Peruviella 

dolium (Roemer).

a, b. Back and front views (X 1) of the holotype 

from the Habana Formation in Oriente 

Province, Cuba (USGS 19464; USNM 

251302).

c. Axial section (X 1.5) of a para type from the 

type locality (USGS 19464, USNM 251303). 

d, e. Sogdianella peruviana (Olsson). Front and back views 

(X 1) of the holotype from the Pananga Formation, Pan de Azucar, Amotape region Peru. Paleontological Research Institute, Ithaca, N.Y.) 

f—k, Peruviella dolium (Roemer)

/. Front view (x 1) of a specimen from the 

Finlay Limestone (?), at Flat Mesa, El 

Paso County Tex. (USGS 1809; USNM 

77559).

g. Front view (x 1) of a specimen from the 

same locality as figure / (USGS 1809; 

USNM 253110).

h. Front view (X 1) of a specimen from the 

same locality as figure / (USGS 1809; 

USNM 253110).

i. Axial section (x 1) of a specimen from the 

Finlay Mountains. Hudspeth County, Tex. 

(USGS 1909; USNM 251308). 

j. Axial section (X 1) of a specimen from

Lower Cretaceous of Texas (TU21030). 

k. Back view (x 1) of a specimen from the 

Finlay Limestone (?) at Flat Mesa, El 

Paso County, Tex. (USGS 1809; USNM 

253112).

Peruviella Olsson has wide whorls with a longer 

anterior canal than Sogdianella, and the columella 

has much hollow space between the central pillar and 

the columellar lip of the following whorls.

In Ovactaeonella Djililov, the whorls are broadly 

rounded at the base and the shell has, at least in later 

growth stages, an umbilicus. Omphaloactaceonella 

Hacobjan, 1972, is so similar morphologically that 

we here place it in synonomy of Ovactaeonella.

Sogdianella ranges from strata of Albian Age 

through the Late Cretaceous. Both the earliest record (Sogdianella peruviana (Olsson)) and the 

youngest record (Sogdianella subcylindrica Kollmann and Sohl) are from the Western Hemisphere. 

Through middle Cretaceous time, however, Sogdianella is known only from central Europe, the Middle 

East and Transcaucasia. The lack of record in North 

and South America from Cenomanian time to the 

Maestrichtian may, however, be due to lack of knowledge and proper fades rather than absence of the 

genus.

Sogdianella subcyclindrica, Kollman and Sohl, n. sp.

Figures 6 a, b, c

1955. Actaeonella (Volvulina) n. sp. Lewis and Straczek, 

U.S. Geol. Survey Bull. 975-D, p. 194.

Diagnosis.—A Sogdianella with a moderate apical 

perforation and a body whorl that is, in profile, 

slightly depressed medially.

Description.—Medium-size, subcylindrical involute shells; body whorl slightly depressed medially; 

uppermost part in small growth stages has an obtuse 

tip; in later stages rounded and in the last growth 

stages moderately perforate. Aperture very narrow, 

slightly wider in lower part; columella short with 

three plaits that decrease in strength anteriorly, 

lowermost one is very weak and rounded on top. 

Edge of columella bends downward just outside 

aperture; basal lip narrow, slightly beaklike, prolonged, and excavated over its whole width.

Measurements.—Holotype, H, 66.6mm; MD, 36.1 

mm. Paratype, H, 53.2mm; MD, 25.8mm.

Discussion.—Although the aperture of the holotype is broken, the narrow basal lip is preserved 

and together with the palatal lip forms the characteristic small beaklike protrusion (fig. 6a). The 

three columellar plaits, the completely involute 

shell in juvenile stage, and the posterior perforation or pit in large shells are all features characteristic of Sogdianella. •

Sogdianella peruviana Olsson has more convex 

whorl sides and is, thus proportionally more narrow 

both anteriorly and posteriorly.
A12 SHORTER CONTRIBUTIONS TO PALEONTOLOGY, 1979

Occurrence.—Habana Formation; (USGS 19464) 

25.5 km east of Central Miranda, on the La CaobaSumidero road, Oriente Province, Cuba.

In addition, several incomplete specimens from the 

Habana Formation on the El Macho River, south 

coast of Oriente Province, Cuba (USGS 23743), 

may belong to this species.

Age.—Available evidence from associated fossils 

suggests a Maestrichtian Age. Reeside (in Lewis 

and Staczek, 1955) considered the Habana Formation in which Sogdianella has been found as "late 

Upper Cretaceous."

Types.—Holotype, USNM 251302. Paratype, 

USNM 251303.

Sogdianella peruviana (Olsson)

1934. Actaeonella peruviana Olsson, Bulls. Am. Paleontology, 

v. 20, no. 69, p. 71-72, pi. 9, fig. 7.

Description (from Olsson, 1934), p. 71.—"Shell 

large, elongate, cylindrical, somewhat broader in the 

anterior portion than in the posterior; body-whorl 

completely enveloping the preceding whorls but with 

the posterior portion of the shell somewhat contracted and produced; section of the shell shows 

numerous whorls which are not resorbed; columella 

with three plaits; external surface smooth; aperture 

narrow, linear, following the contour of the shell."

Measurements.—The holotype of S. peruviana 

(Olsson) measures 104 mm (posterior end lacking) 

in total height and has a maximum diameter of 

30mm.

Discussion.—Olsson (1934, p. 72) indicated that 

Sogdianella peruviana is among the most common 

and characteristic fossils present in limestone of the 

Pananga Formation of the Amotape region of northern Peru. Unfortunately, only the holotype is available for study as Dr. K. Palmer (written commun., 

1974) stated that no additional specimen of the species are present in the collections of the Paleontological Research Institute, Ithaca, N.Y. As shown in 

figure Qd, the holotype lacks the upper part of the 

aperture, and the columellar plaits are not readily 

apparent. Thus, information on variability and 

plait characters must rest on Olsson's description 

and discussion, which was evidently based upon sections made from specimens other than the holotype. 

In his discussion of S. peruviana, Olsson (1934) 

mentioned that young shells are less cylindrical than 

the adult forms and that sections show numerous 

whorls.

Although the holotype is not sufficiently preserved 

for positive generic identification, its similarity to 

the specimens described under S. aff. S. peruviana

makes a strong argument for their placement in 

Sogdianella.

Occurrence.—Pananga Formation, Pan de Azucar, 

Quebrada Muerto, and Quebrada Culebra, Peru 

(Olsson, 1934).

Age.—Albian.

Type.—Holotype, Paleontological Research Institute, Ithaca, N.Y.

Sogdianella aff. S. peruviana (Olsson)

Figure 4a

1928. Actaeonella (Volvulina) sp. Gerth, Leidse Geol. Meded., 

v. 1928, pt. 2, Afl. 4, p. 233.

Discussion.—Six specimens in the collections of 

the U.S. Geological Survey from Cerro Negro, Paita 

Region, northern Peru (USGS 31236) may be related to Olsson's species. They differ mainly in having more convex sides and are broader proportional 

to height. They are similar to A. peruviana Olsson 

in the many narrow whorls seen in section and in 

the whorls being almost equally narrow in both 

anterior and posterior parts of the whorl (fig. 4a). 

The shells lack a palatal ridge, the columella is broad 

and low, and anteriorly it is strongly inclined toward 

the shell axis. The columella bears three plaits that 

decrease in strength anteriorly and is concave below 

the plaits.

The above mentioned features are characteristic 

of Sogdianella. Their specific identity with Actaeonella peruviana Olsson is tentative not only because 

of the morphologic differences mentioned above, but 

also because of differences in age of the two stratigraphic levels represented. Actaeonella peruviana 

Olsson occurs associated with an Albian ammonite 

assemblage (Olsson, 1934, p. 13). Our specimens 

seemingly come from the "Actaeonellen-Rudistinkalkstein" of Gerth (1928), which Olsson (1944, p. 

15) has called the "Actaeonella limestones." This 

limestone occurs above beds containing sphenodiscid 

ammonites. The presence of Praebarrettia peruviana 

Gerth in these beds suggests that the age is early 

Maestrichtian. Olsson himself vascillated on the 

affinities of the "Actaeonella limestone" gastropod 

species, first (Olsson, 1934, p. 10) considering the 

two to be possibly the same, but later (Olsson, 

1944, p. 72) stating that the two were probably 

distinct.

Although the generic status of Actaeonella peruviana Olsson cannot be proved, its gross similarity 

to the specimens discussed here from Cerro Negro 

suggests that it belongs in Sogdianella.

Occurrence (USGS 31452).—"Actaeonella limestone," Cerro Negro, Paita Region, Peru.
WESTERN HEMISPHERE CRETACEOUS ITIERIIDAE GASTROPODS A13

Age. — Early Maestrichtian. 

Type.— Hypotype USNM 251304.

Genus Peruviella Olsson, 1944 

(Synonym: Peruvia Olsson, 1934 non Peruvia Scudder, 1890.)

Type species. — Peruvia gerthi Olsson, 1934, by 

original designation.

Diagnosis. — Globose shell with involute to immersed apex. Aperture with basal beak, columella 

either solid or hollow, and bearing three plaits.

Discussion. — Olsson described this genus first in 

1934 and named it Peruvia. As that name was preoccupied, he substituted Peruviella (Olsson, 1944). 

The following description of the genus is taken from 

Olsson, 1934 :

Shell ovate, globose; the spire is pointed, its sides impressed 

but completely enveloped by the last whorl; base of the shell 

is rounded with a short, projecting beak; aperture narrow, 

somewhat wider in front and extending the full length of 

the shell; the pillar and the anterior portion of each whorl is 

strongly thickened with callous deposit; columellar folds are 

absent at maturity or they are reduced to a single, small plait 

situated at the upper edge of the callus on the parietal wall.

An examination of the holotype of the type species Peruviella gerthi shows that the first whorls of 

the shell and the basal parts of the whorl are filled 

with calcite (fig. 5/). As the shell is also calcified, 

the plaits are hardly visible. Other paratypes show 

three plaits clearly (fig.

Peruviella gerthi Olsson, 1934

Figures 4d, 5f-k

1928. Actaeonella cf. gigantea Sowerby.- Gerth, H., Leids.

Geol. Meded., v. 1928, pt. 2, An. 4, p. 232-241. 

1934. Pervia gerthi Olsson, Bulls. Am. Paleontology, v. 20,

no. 69, v. 59, p. 73, pi. 9, fig. 1-3. 

1936. Trochactaeon sergipensis Maury. Brazil, Service Geol.

Mineralog. Mon., v. 11, p. 222 (225) pi. 13, figs. 2,

5, 6, 8. 

1944. Peruviella gerthi Olsson. Bulls. Am. Paleontology, v.

28, no. Ill, p. 6.

Diagnosis. — A Peruviella with the upper part of 

the whorls compressed and the base of the aperture 

extended to a beaklike process.

Description (from Olsson, 1934, p. 73).— "Shell of 

medium size, ovate, globose; spire completely enveloped by the last turn but with the posterior or 

apical portion of the shell somewhat produced and 

pointed ; the sides of the whorls in the posterior region are noticeably impressed, while just below the 

whorl appears slightly shouldered; the base of the 

body whorl is rounded ending in a small, projecting 

beak; surface smooth except for lines of growth; 

character of complete aperture unknown * * * 

(Olsson, 1934).

70

60

50 -

40

30

20 i-

+ •«,*

10 20 30 40 50 60 70

MAXIMUM DIAMETER, IN MILLIMETERS

FIGURE 7.—Relationship of height and maximum diameter in 

Peruviella gerthi Olsson (cross) and Peruviella dolium 

(Roemer) (circle).

Measurements (fig. 7).—Holotype: H, 63.0 mm; 

MD, 45.0 mm (upper part of shell incomplete). 

Paratypes: H, 39-51 mm; MD, 57-71 percent of 

total height.

Discussion.—Restudy of the available material 

provides the following additional information on 

shell characters. The middle of the shell is consistently the broadest dimension. The columella of 

Peruviella gerthi is highly inclined to the shell axis 

(fig. 5;) and bears three plaits of which the posterior-most is stronger than the others and is inclined upward. The columella below the plaits constitutes about one-third its total height.

The species Trochactaen sergipensis from Brazil, 

described by Maury (1936, p. 222), appears to belong to this species. In addition to Maury's illustrations, we have been able to examine two specimens 

collected by Peter Bengston of the University of 

Uppsala, Sweden. These specimens came from the 

Carapeba Quarry, 2.4 km northwest of the village 

of Pedra Branca on the west side of the Pedra 

Branca to Riachuelo road in the State of Sergipe, 

Brazil. The specimens were collected from an oolitic 

limestone within the Maruin Member of the Riachuelo Formation. Associated with the Peruviella 

specimens were the ammonites Elobiceras inter-
A14 SHORTER CONTRIBUTIONS TO PALEONTOLOGY, 1979

medium Spath and Elobiceras subelobiense Spath 

indicative of a late Albian Age. Although this is not 

the same locality as that from which Maury's specimens came, they are from the same stratigraphic 

unit.

Compared with Peruviella dolium this species is 

proportionally narrower (compare figures 4d and 4/ 

and g) and has a longer columella.

Occurrence.—Peru, Pananga Formation at Pan de 

Azucar, Amotape region. Brazil, Riachuelo Formation, Marium Member, near Riachuelo, Sergipe 

Province.

Age.—Middle to late Albian.

Type.—Holotype, PRI 3753. Paratype, PRI 3752. 

Hypotypes, USNM 251305, 251306.

Peruviella dolium (Roemer), 1849

Figures 4e-g, 6f-k

1849. Actaeonella dolium Roemer, Texas, p. 411.

1852. Actaeonella dolium Roemer. Roemer, Die Kreidebildungen von Texas, p. 43, pi. 4, fig. 4. 

1888. Acteonella anchietai Choffat in Choffat and de Loriol,

Soc. Physique et Histoire Nat. Geneve Mem, v. 30, no.

2, p. 73, pi. 3, fig. 3-5. 

1928. Volvulina texana (Roemer). Adkins, Texas Univ. Bull.

2838, p. 196.

1947. Actaeonella dolium Roemer. Stanton, U.S. Geol. Survey Prof. Paper 211 p. 109, pi. 67, figs. 1, 3, 4, 7, 10-12. 

1956. Actaeonella anchietai Choffat. Darteville and Brebion.

Mus. Royal Congo Belg Ann., Sci. geol. v. 15, p. 95 (all

records in Africa).

Diagnosis.—A Peruviella that has a broadly oviform to globular and anomphalous shell. Small shells 

are involute, but larger shells are apically perforate. 

The columella is proportionally short.

Description (from Roemer, 1852).—"Shell rather 

long; truncate at the base, pointed at the top, surface smooth; without spire, whorls concealed by the 

preceding ones; much broader at the lower end, 

sloping slowly to the upper end; inner surface folded 

near the base; three regular and acute plaits."

Supplementary description.—Shell form varies according to growth stage, small specimens are strongly convex medially, apical slopes broadly concave 

terminating in pointed apex (fig. 6#) ; large specimens have a barrellike to globular form with midwhorl only slightly convex to vaguely concave, apical 

and basal slopes broadly rounded. Shell completely 

involute in early stages but in later stages body 

whorl not completely enveloping thus leaving an 

apical pit (fig. 61). Growth lines are broadly sinuate 

over upper half whorl surface in area coincident 

with maximum shell diameter. Aperture narrow 

throughout length, anterior part terminates in a

small beak. Columella, in form of an inverted cone, 

is hollow between beak and preceding whorl, bears 

three equally spaced plaits over upper part, and is 

smooth over an equal distance anteriorly.

Measurement (fig. 7).The holotype is an internal 

mold of no value for measurement. Other specimens 

are as much as 93 mm in height and have a maximum diameter of about 60-100 percent of total 

height.

Discussion.—Peruviella dolium (Roemer) is a 

widely distributed species that is variable in several 

morphologic features. For example, the apical pit is 

exceptionally large in globular specimens from the 

Finlay Mountains (Fredrickburgian) of west Texas 

(USGS 1909, see fig. 6i). Stanton (1947, p. 110) 

mentioned that a large suite of specimens collected 

near Sierra Blanca, also in west Texas, showed a 

typically larger size and lesser convexity of whorls, 

and he suggested that they might deserve subspecific 

distinction. Reexamination of these collections shows 

a polymorphous assemblage of specimens, which, although variable, show intergradation of character 

that provides no justifiable basis for separation. The 

range of variability of the material from the lower 

and middle Albian of Texas encompass the form described from the Albian of Dombe-Grande Angola by 

Choffat (1888) as Actaeonella anchietai.

The maximum diameter of Peruviella gerthi 

Olsson is proportionally smaller compared with its 

total height than is P. dolium (compare figs. 5k, 6k) 

and even in large shells the upper part is pointed 

and has concave sides. In addition, the columellar 

lip is higher within the whorls and not so much inclined (compare figs. 4d! and g). The Late Cretaceous 

species of Peruviella described by Djalilov (1972) 

from the U.S.S.R. are all broadly umbilicate.

Types.—Holotype, University of Bonn, Germany. 

Hypotypes, USNM 77559, 251307, 251308.

Occurrence—Texas.—The holotype is believed to 

be from an unknown position within the Fredrickburg Group (middle Albian) near Fredericksburg. 

Tex. Paluxy Sand, between Bertram and Hopewell, 

Coryell County (UT 1029) : Walnut Clay, road cut 

just west of Gatesvile, Coryell County; Cox Sandstone (and (or) Finlay Limesone) ; Eagle Mountain 

(UT 8402, 8407, 8408; Finlay Mountains (USGS 

1909, 1922) ; Quitman Canyon (USGS 1912, 1917) ; 

Sierra Blanca (USGS 1809, 1812, 15974) ; Eagle 

Flat area (USGS 3603) ; Bell County, locality and 

stratigraphic position unknown (USNM 8306b) ; 

Lampasas County, locality and stratigraphic position unknown (USNM 18802).
WESTERN HEMISPHERE CRETACEOUS ITIERIIDAE GASTROPODS A15

Mexico.—Cox Formation, Sierra Pilares (UT 

31437) and Benevides (UT 43538) State of 

Chihuahua.

Angola.—Dombe-Grande.

Age.—Early to middle Albian in North American 

and middle to late Albian of Angola.

REFERENCES CITED

Adkins, W. S., 1928, Handbook of Texas Cretaceous fossils: 

Texas Univ. Bull. 2838, 385 p., 37 pi.

Aguilera, J. G., 1906, Excursion de Tehuacan a Zapotitlan et 

San Juan Raya [Mexico] : Internat. Geol. Cong., 10th, 

Mexico 1906, Guide Excursions no. 7, 27 p.

Choffat, Paul 1888, V. Mollusques in Choffat, Paul, and de 

Loriol, Percival, Materiaux pour 1'etude stratigraphique 

et paleontologique de la province d'Angola: Soc. Physique 

et Histoire Nat. Geneve mem., v. 30, no. 2, 116 p., 4 pis.

Cossmann, Maurice, 1896. Essais de Paleoconchologie Comparee: Paris, Presses Universitaires de France, no. 2, 

179 p., 8 pi.

Cserna, G. Alencaster, de, 1956, Pelecipodos y gasteropodos 

del Cretacico Inferior de la region de San Juan RayaZapotitlan, Estado de Puebla. Mexico Univ. Nac. Inst. 

Geologia Paleontologia Mexicana, no. 2, 47 p., 7 pi.

Darteville, Edmond, and Brebion, Phillipe, 1956, Mollusques 

fossils du Cretace de la Cote occidentale d'Afrique du 

Cameroun a 1'Angola, I, Gasteropodes. Mus. Royal Congo 

Beige Ann., ser. in-8°, Sci geol., v. 15, 128 p.

Darteville, Edmond, and Freneix, Suzanne, 1957, Mollusques 

fossiles du Cretace de la Cote occidentale d'Afrique du 

Cameroun a 1'Angola, II, Lamellibranches. Mus. Royal 

Congo Beige Ann., ser. in-8°, Sci. geol., v. 20, 271 p., 

34 pi.

Djalilov, M. R., 1972, [Systematics of actaeonellids (Gastropoda)] : Paleont. Zhur., 1972, no. 1, p. 16-23 (In Russian; 

English translation pub. by Am. Geol. Inst.: Paleont. 

Jour., v. 6, no. 1, p. 13-19.)

Douville, Henri, 1921, Melanges Paleonotologiques—Genre 

Eovasum, Glauconiidae, Pleuroceratidae, Pirenidae, Genrs 

Itruvia: Jour. Conchyliologie, v. 66, p. 1-18, pi. 1, 2.

Gerth, H., 1928, Neue Faunen der oberen Kreide mit Hippuriten aus Nordperu: Leidse. Geol. Meded., v. 1928, pt. 2, 

Afl. 4, p. 231-241.

Hacobjan, V. T., 1972, [Systematics of Late Cretaceous Trochactaeonids (Gastropoda)]: Paleont. Zhur., 1972, no. 1, 

p. 3-15, pi. 1, 2 (In Russian; English translation pub. by 

Am. Geol. Inst.: Paleont. Jour., v. 6, no. 1, p. 1-12.)

Imlay, R. W., 1941, Jurassic fossils, from Arkansas, Louisiana, and eastern Texas: Jour. Paleontology, v. 15, no. 3, 

p. 256-277, pis. 38, 39.

Kollmann, H. A., 1965, Actaeonellen (Gastropoda) aus der 

ostalpinen Oberkreide: Naturh. Mus. Wien Ann., v. 68, 

p. 243-262, pis. 1-4.

————1968, Itruvien (Itieriidae, Gastropoda) aus dem 

Wiener Raum Geol. Gesell. Wien Mitt., v. 60, p. 13-22.

Lewis, G. E., and Straczek, J. A., 1955, Geology of southcentral Oriente, Cuba: U.S. Geol. Survey Bull. 975-D, p. 

171-336.

Lupu, Denisa. 1986, Studiul Faunei de Gastropode Cenomaniene de la Cherghes: Rev. Roumaine Geologic, Geophysique et Geographic, Ser. Geologic, v. 10, no. 1, p. 115- 

126, pi. 1-4.

Maury, C. J., 1936, O Cretaceo de Sergipe: Brazil, Service 

Geol. Mineralog Mon., v. 11, 283 p., 28 pi.

Mazeran, Pierre, 1912, Sur un genre nouveau de Gesteropodes 

du Cretace superieur: Soc. Linneenne de Lyon Ann., v. 

59, p. 163-172.

Olsson, A. A., 1934, Contributions to the paleontology of 

northern Peru—The Cretaceous of the Amotape region: 

Bulls. Am. Paleontology, v. 20, no. 69, 102 p., 10 pis.

————1944, Contributions to the paleontology of northern 

Peru, pt. 7, The Cretaceous of the Paita Region: Bulls, 

Am. Paleontology, v. 28, no. Ill, 147 p., 17 pis.

Orbigny, Alcide d', 1842-1947, Description des animaux invertebres; 2 Gasteropodes: Paleontologie francaise, terrain Cretace, le ser., v. 2, 456 p., pis. 149-236.

Pchelintsev, V. F., [Ptselintsev], 1953, Fauna bryukhonogikh 

verkhenemelovykh otlozhenii Zakavkazya i Srednei Azii 

[Gastropod fauna of the Upper Cretaceous deposits of 

Transcaucasia and Central Asia]: Moscow-Leningrad, 

Akad. Nauk SSSR, Geol. Muz. im A. P. Karpinskogo, 391 

p., 51 pis., 47 text figs.

————1954, Bryukhonogie verkhnemelovykh otlozhenii Armyanskoi SSR i prilegayushchei chasti Azerbaidzhanskoi 

SSR [Gastropods from the Upper Cretaceous beds of the 

Armyansku SSR and overlying parts of Azerbaidzhan 

SSR]: Moscow-Leningrad, Akad. Nauk SSSR, Geol. 

Muz., 180 p., 23 pis., 52 text figs.

Phillippi, R. A., 1851, Tiber Tornatella abbreviata, Otodus 

mitis, Otodus catticus and Myliobatis testae: Palaeontographica, v. I, p. 23-25, pi. 2.

Rahman, A., 1967, Die Gastropoden der Oberkreide von H61- 

zelsau bei Niederndorf in Tirol: Mitt. Bayern Staatssaml. 

Palaontologische hist. Geol. Heft 7, Munchen. p. 23-134, 

pi. 3-7.

Roemer, Ferdinand, 1849, Texas: Bonn, Adolf Marcus, 464 p.

————1852, Die Kreidebildungen von Texas und ihre organischen Einschlusse: Bonn, Adolf Marcus, 100 p., 

11 pis.

Stanton, T. W., 1947, Studies of some Comanche pelecypods 

and gastropods: U.S. Geol. Survey Prof. Paper 211, 256 

p., 67 pis.

Stoliczka, Ferdinand, 1867-68, Cretaceous fauna of southern 

India, v. 2 of The Gastropoda of the Cretaceous rocks of 

southern India: India Geol. Survey Mem., Paleontographica India, ser. 5, pts. 1-10, 497 p., 28 pis.

Wenz, Wilhelm, 1938-44, Gastropoda, pt. 1 of Prosobranchia, 

in Schindewolf, 0. H., ed., Handbuch der Palaozoologie: 

Berlin, Gebriider Borntraeger, v. 6, 1639 p., 4211 text 

figs.

Zilch, Adolph, 1959-60, Gastropoda, pt. 2 of Euthyneura, in 

Schindewolf, O. H., ed. Handbuch der Palaozoologie: 

Berlin, Gebruder Borntraeger, v. 6, 835 p., 2515 figs.

Ostracode Biostratigraphy of 

Pliocene and Pleistocene Deposits 

of the Cape Fear Arch Region, 

North and South Carolina

By THOMAS M. CRONIN and JOSEPH E. HAZEL

SHORTER CONTRIBUTIONS TO PALEONTOLOGY, 1979

GEOLOGICAL SURVEY PROFESSIONAL PAPER 1125-B

CONTENTS

Page

Abstract ___________________________________________ Bl

Introduction __________________________________________ 1

Acknowledgments _________________________________________ 1

Lithostratigraphic units ______________________________________________ 2

Physiographic units ______________________________________ 3

Biostratigraphy _____________________________________________ 4

Chronozones of ostracode assemblage-zones _____________________ — ____ 4

Local range-zones _______________________________________________—____ 6

Regional correlation ______________________________________ 7

Conclusions __________________________________________________________ 7

Collection localities ________________________________________ 9

References cited ______________________________________ 10

ILLUSTRATIONS

[Figures 4-9 follow Eeferences Cited]

Page

FIGURE 1. Generalized geologic map of Pliocene and Pleistocene formations in the study area, the Cape Fear

Arch region of North Carolina and northeastern South Carolina, showing major scarps and barriers B2

2. Range chart for 50 ostracode species whose range-zones and concurrent-range-zones are useful in recognizing the chronozones of ostracode assemblage-zones in the Cape Fear Arch area ______________ 5

3. Tentative correlation chart for Pliocene and Pleistocene deposits of southern Virginia, North Carolina,

and northeastern South Carolina _______________________________________________ 8

4-9. Photographs of:

4. Puriana, Radimella, and Malzella _______________________________________________________ 14

5. Bensonocythere _____________________________________________________________________ 16

6. Bensonocy there, Muellerina, Hermanites, and Actinocythereis _____________________________ 18

7. Microcytherura and Paracytheroma ____________________________________________________ 20

8. Paracytheridea, Orionina, Neocaudites, Caudites, and Hulingsina _________________________ 22

9. Loxoconcha, Perissocytheridea, Echinocythereis, and Palaciosa _________________________ 24

TABLE

Page

TABLE 1. Alphabetical listing of species used in this study _____________________________________ B4

III

SHORTER CONTRIBUTIONS TO PALEONTOLOGY, 1979

OSTRACODE BIOSTRATIGRAPHY OF PLIOCENE AND PLEISTOCENE

DEPOSITS OF THE CAPE FEAR ARCH REGION,

NORTH AND SOUTH CAROLINA

By THOMAS M. CRONIN and JOSEPH E. HAZEL

ABSTRACT

Species-range and concurrent-range-zones of ostracode 

species from the Duplin, "Bear Bluff," Waccamaw, and 

"Canepatch" Formations (Pliocene and Pleistocene) were 

determined from numerous samples from the Cape Fear 

Arch region, North and South Carolina. On the basis of 

occurrence data, chronozones of the Orionina vaughani and 

Puriana mesacostalis Assemblage-Zones established for the 

Virginia and northern North Carolina region can be recognized in the Cape Fear Arch region and as far south as 

the Santee River, S.C. Deposits mapped as the Duplin Formation (Pliocene) represent the chronozone for the Orionina 

vaughani Assemblage-Zone and are in part equivalent to the 

Yorktown Formation. Deposits of the Bear Bluff (upper 

Pliocene) and the Waccamaw (Pleistocene) Formations correspond respectively to the lower and upper parts of the 

Puriana mesacostalis Assemblage-Zone and are time equivalents of the lower and upper beds in the Croatan Formation. Middle Pleistocene deposits mapped as the Canepatch 

Formation yielded distinctive assemblages containing high 

percentages of extant species.

INTRODUCTION

Recently, Hazel (1971a, 1977, 1980) proposed 

quantitatively defined ostracode assemblage-zones 

and determined biostratigraphically diagnostic species-range and concurrent-range-zones for Pliocene 

and lower Pleistocene deposits of Virginia and 

northern North Carolina. From previously published 

data and analysis of new ostracode samples, Hazel 

(1977) presented a correlation scheme for the Pliocene and lower Pleistocene deposits of the central 

and southern Atlantic Coastal Plain and Florida. In 

connection with several U.S. Geological Survey 

projects, many Pliocene and Pleistocene samples 

have been obtained from the Cape Fear Arch region 

of North and South Carolina. Calcareous microfossils from these samples, particularly ostracodes, are 

presently being studied for their biostratigraphic,

paleoecologic, and systematic value. This paper presents preliminary biostratigraphic results of this 

study. Figure 1 shows the region of study, which extends from the South River, N.C., south to the Santee 

River, S.C.

The stratigraphic distribution of ostracode species 

in deposits mapped as Duplin, "Bear Bluff," Waccamaw, and "Canepatch" Formations has been determined. The "Bear Bluff" and "Canepatch" are 

terms introduced by DuBar (1971) and DuBar and 

others (1974). They are used informally in this 

paper. Many ostracode species from these deposits 

were found by Hazel (1971a, 1977) to be useful 

biostratigraphic indicators in Pliocene and lower 

Pleistocene deposits of Virginia and northern North 

Carolina. Some of the chronozones of the ostracode 

assemblage-zones proposed by Hazel (1971a) can be 

recognized in the Cape Fear Arch region by the 

presence of species having limited stratigraphic 

ranges and by the concurrent-range-zones of several 

pairs of species. Thus, the biostratigraphic equivalents of the ostraciode zones established for regions 

to the north can, at least in part, be recognized 

south to about the Santee River, S.C. Moreover, 

other species, rare to absent in deposits north of 

Cape Hatteras (north of area shown on fig. 1), were 

found to have relatively short local stratigraphic 

ranges in the study area; hence, they are useful for 

correlation of lithostratigraphic units within the 

Cape Fear Arch region.

ACKNOWLEDGMENTS

Blake W. Blackwelder, U.S. Geological Survey, 

and Jules R. DuBar, Morehead State University, 

Morehead, Ky., freely gave their insights into Atlantic Coastal Plain geology.

Bl
B2 SHORTER CONTRIBUTIONS TO PALEONTOLOGY, 1979

80°

NORTH CAROLINA 

SOUTH CAROLINA

Mechanicsville 

Scarp

° C CAPE FEAR 

\ EXPLANATION

Jaluco Barrier

MYRTLE 8EACH

Undifferentiated modern flood plain an

Pleistocene fluvial terrace deposits 

"Waiter Island Formation" 

"Socastee Formation" 

"Canepatch Formation" 

Waccamaw Formation 

"Bear Bluff Formation" and

Holocene

Pleistocene

Upper

Upper or middle 

Middle or lower

Lower Pleistocene 

or Pliocene "Marietta Formation" 

Duplm Formation

Paleocenel?) and 

Upper Cretaceous Undifferentiated 

Contact-Approximately located 

Scarp-Hachures on elevated side 

Barrier

20 MILES

j

20 KILOMETERS

FIGURE 1.—Generalized geologic map of Pliocene and Pleistocene formations in the study area, the Cape Fear Arch region of 

North Carolina and northeastern South Carolina, showing major scarps and barriers. (Adapted from DuBar and others, 

1974).

LITHOSTRATIGRAPHIC UNITS

The term "Duplin Beds" was proposed by Dall 

(1898, p. 338) for "late Miocene" shelly marls in 

Duplin County, N.C. In 1903, Dall listed molluscan 

species from Natural Well, Magnolia, N.C., a locality 

that has since been regarded as the Duplin type locality (see DuBar and others, 1974). B. L. Miller 

(Clark and others, 1912) was first to use the term 

"Duplin Formation" for these deposits. In the Cape 

Fear Arch area, the Duplin Formation rests on Cretaceous to Paleocene strata and is exposed at the 

surface between the Orangeburg and Mechanicsville

Scarps (fig. 1). Consisting of calcareous silt and 

sand, the Duplin Formation extends from the study 

area north to the Neuse River and south into 

Georgia. Whereas earlier workers assigned the Duplin a late Miocene age, recent work has shown that 

the Duplin is in fact Pliocene (Akers, 1972; Akers 

and Koeppel, 1974; Hazel, 1977, 1980).

Previous studies of Duplin ostracodes include 

those by Edwards (1944), Brown (1958), and Swain 

(1952) for North Carolina; Pooser (1965) for 

South Carolina; and Howard (1974) for the Cape 

Fear Arch region. Material for the present study 

comes from the type locality of the Duplin at Natural
OSTRACODE BIOSTRATIGRAPHY, NORTH AND SOUTH CAROLINA B3

Well, Magnolia, N.C. (loc. 16) ; four samples come 

from outcrops on the Lumber River near Lumberton, 

N.C. (loc. 15) ; and six samples come from the 

Robeson family farm, Robeson County, N.C. (loc. 

14). Locality data for the studied samples are given 

in the Collection Localities section at the end of this 

report.

DuBar (1971) named the Bear Bluff Formation 

for a sequence of calcareous sandstone and sandy 

limestone cropping out along the Waccamaw River 

in Horry County, S.C. The Bear Bluff has been 

traced in the subsurface from southeastern North 

Carolina to the Santee River and from the coast inland to the Surry Scarp. DuBar and others (1974) 

assigned the Bear Bluff Formation a late Pliocene 

or early Pleistocene age, and Hazel (1977) considered it late Pliocene.

Except for the few data used by Hazel (1977), 

ostracodes from the Bear Bluff Formation have not 

been described or listed in detail. Howard (1974) 

stated that the lower parts of deposits from North 

Carolina, which he called the Waccamaw Formation, 

may actually be the Bear Bluff Formation of DuBar 

(1971), but Howard could not distinguish the two 

formations.

Ostracode material from the Bear Bluff for the 

present study came from the William Bird Ashley 

mine (loc. 17) near Conway, S.C., the Intracoastal 

Waterway, Horry County, S.C. (Iocs. 2 and 5), and 

the open pit mine at Calabash, N.C. (loc. 12). An 

additional sample from a Horry County drill hole 

(loc. 13) was obtained from J. R. DuBar.

Fossiliferous clayey and silty quartzose sands exposed along the Waccamaw River, Horry County, 

S.C., were named the "Waccamaw Beds" by Dall 

(1892). Deposits of the Waccamaw Formation are 

present east of the Surry Scarp and from the Cape 

Fear River south as far as Charleston, S.C. Stratigraphically, the Waccamaw Formation is above the 

Bear Bluff and below the Canepatch Formations. Recent stratigraphic and faunal evidence suggests that 

the Waccamaw Formation is early Pleistocene in 

age (Hazel, 1977; DuBar and others, 1974).

Previous studies of Waccamaw ostracodes include 

those by Swain (1968) and Howard (1974). Abundant material used in the present study was collected from outcrops of the Waccamaw at the following localities: the Intracoastal Waterway, Horry 

County, S.C. (Iocs. 3 and 5) ; Calabash, N.C. (loc. 

12); Walker's Bluff (loc. 7), Greenback Landing 

(loc. 10), and Niels Eddy Landing (loc. 9) on the 

Cape Fear River, N.C.; Old Dock, N.C. (loc. 6) ; the 

Town Creek Pierce Brothers Pit, Brunswick County,

N.C. (loc. 8) ; the pit west of Acme, Columbus 

County, N.C. (loc. 11) ; and the type Waccamaw locality (loc. 1) near Tilly Lake on the Waccamaw 

River, S.C.

The term "Canepatch Formation" has been used 

by DuBar (1971) and DuBar and others (1974) for 

lithologically variable deposits exposed along the 

Intracoastal Waterway, Horry County, 10.4 km 

northeast of Myrtle Beach, S.C. Forming the surface of the Jaluco-Cainhoy and Conway Barriers, the 

Canepatch Formation unconformably overlies the 

Waccamaw, Bear Bluff, and Duplin Formations and 

other older deposits. It consists of a complex of sand, 

clay, silt, and peat deposited in barrier, estuarine, 

lagoonal, and shelf environments. DuBar and others 

(1974) assigned a middle to late Pleistocene age to 

the Canepatch Formation. Material for the present 

study comes from exposures of the Canepatch Formation on the Intracoastal Waterway, Horry County 

(Iocs. 2, 3, 4, and 5). No data on Canepatch ostracodes have been published previously.

PHYSIOGRAPHIC UNITS

The Duplin, Bear Bluff, Waccamaw, and Canepatch Formations were deposited during submergent periods of submergent/emergent cycles related 

to glacial eustatic adjustments, possibly complicated by tectonic movements (see below). However, 

any discussion of Atlantic Coastal Plain deposits 

must include consideration of the physiographic 

units that owe their formation to these submergent 

episodes. These features include many prominent 

shoreline scarps and terrace-formations for which a 

complex nomenclature has evolved (Cooke, 1931, 

1932). The traditional approach to correlation of 

these deposits was to associate a shoreline scarp 

with a stand of sea level, a physiographic surface, 

and a lithostratigraphic unit. Thus, for example, the 

Duplin sea shoreline would correspond to the 

Orangeburg Scarp, and sediments that make up the 

Duplin Formation were deposited between the 

Orangeburg Scarp and the topographically lower 

Mechanicsville Scarp. Early workers, most notably 

Cooke (1936, 1943), correlated these units solely on 

the basis of their altitude. This approach, however, 

has serious drawbacks. It assumes that once a shoreline scarp has been formed, sea level never reaches 

that position again. Recent evidence indicates that 

Pliocene and Pleistocene inundations may have 

reached the Mechanicsville and Surry Scarps (fig. 

1) more than once (DuBar and others, 1974). Consequently shoreline-scarp and terrace formation
B4 SHORTER CONTRIBUTIONS TO PALEONTOLOGY, 1979

seems to result from a more complex geological history than previously believed. More importantly, 

the technique of correlation on the basis only of 

altitude hinges on the assumption that the Atlantic 

Coast has been tectonically stable during the Pliocene and Pleistocene, an assumption that appears to 

be unwarranted in light of recent evidence. Bloom 

(1967) was one of the first to warn against correlation of terraces simply by their altitude. Recently, 

Winker and Howard (1977), using topographic 

maps as data, suggested that relict shorelines are 

neither horizontal nor parallel to each other. Thus, 

correlation by altitude is unreliable, and alternative 

means of correlation must be sought for a better 

understanding of the relationships between the 

physiographic and lithostratigraphic units and the 

history of submergence and tectonic warping. In 

light of this need, the present study attempts to enhance our biostratigraphic correlation techniques for 

the Cape Fear Arch region.

BIOSTRATIGRAPHY

Biostratigraphically diagnostic ostracode taxa for 

the Cape Fear Arch region are listed alphabetically 

in table 1. Figure 2 schematically illustrates the 

stratigraphic distribution of 50 selected ostracode 

taxa in the Cape Fear Arch region. Species ranges 

are plotted against a composite lithostratigraphic 

section for the region; hence, range endpoints appear to coincide exactly with f ormational boundaries. 

Species that are common to both the Virginia and 

'northern North Carolina region and the Cape Fear 

Arch region and whose range endpoints and concurrent-range-zones are useful in recognizing the 

chronozones of ostracode assemblage-zones are indicated in figure 2. For the few taxa having different 

stratigraphic ranges in each of the two regions, a 

solid line shows the distribution in deposits in the 

Cape Fear Arch region, and a dashed line shows the 

distribution for Virginia and northern North Carolina, plotted against the assemblage-zonation for 

that region. Figures 4-9 (see the back of this report) illustrate the 50 taxa.

CHRONOZONES OF OSTRACODE ASSEMBLAGE-ZONES

Hazel (1977) suggested that Pliocene and Pleistocene deposits north of the Neuse River, N.C., might 

be correlated with those in the Cape Fear Arch region by using range-zones and concurrent-rangezones of species common to both regions. Indeed, the 

results of the present study indicate that two of the 

chronozones of ostracode assemblage-zones of Hazel

rABUU i. — SLipnavemcai listing oj species useu, in ims siuay

Species

Actinocythereis captionis Hazel

A. captionis Hazel (large form)

Bensonocy there aff . B. bradyi Hazel

B. gouldensis Hazel

B. ricespittensis Hazel

B. rugosa Hazel

B. whitei (Swain) s.s.

B. whitei (Swain) (straight form)

B. sp. A

B. sp. B

B. sp. C

B. sp. D

Caudites paraasymmetricus Hazel

Echinocythereis leecreekensis Hazel

Hermanites ascitus Hazel

Hulingsina sp. N

Loxoconcha edentonensis Swain

L. matagordensis (Swain)

L. sp. A

L. sp. B

Malzella conradi (Howe and

McGuirt)

M. evexa Hazel

M. floridana (Benson and Coleman)

Microcytherura choctawhatcheensis

(Puri)

M. expanda Hazel

M. minuta Hazel

M. similis (Malkin)

M. sp. B

M. sp. C

M. sp. D

Muellerina bassiounii Hazel

M. wardi Hazel

M. sp. B

Neocaudites triplistriatus

(Edwards) s.l.

N. variabilis Hazel

Orionina vaughani (Ulrich and

Bassler)

Palaciosa minuta (Edwards)

Paracytheridea altila Edwards

P. sp. A

P. edwardsi Hazel

P. mucra Edwards

P. rugosa Edwards

Paracytheroma stephensoni (Puri)

Perissocytheridea sp. B

P. sp. C

Puriana carolinensis Hazel

P. convoluta Teeter

P. mesacostalis (Edwards)

P. sp. A

Radimella confragosa (Edwards)

(1971a, 1977) can be recognized

teras; thus, correlation between

Species No. 

(Tig. 2)

38

4

1

14

43

16

29

50

35

3

2

49

42

32

7

48

19

40

6

5

8

15

46

20

31

11

17

36

22

44

27

12

33

25

23

21

41

24

45

26

9

30

39

34

10

13

37

28

47

18

south of

the two

possible by using ostracodes. Additional

and faunal study are still needed , however

Figure No. 

(this report)

60

6/1

6a

5a

56

5c

50

5/i 5'd

66

5e

5/

Si

9/

6/

87

9d

Qc

96

9a

4ft

40

4/

7c

7/

70

Id

75

7a

7e

6e

6c

6d

80

8h

Se

9h

8/

Sc

8d

8a

8&

Ih

90

9e

4&

4d

4c

4a

4e

Cape Hatregions is

sampling

, to obtain
OSTRACODE BIOSTRATIGRAPHY, NORTH AND SOUTH CAROLINA B5

DUPLIN

BEAR BLUFF 

of DuBar (1971.1974) WACCAMAW

CANEPATCH 

of DuBar (1971,1974)

Cape Fear Arch 

area formation

Ononma vaugham 

Assemblage-Zone

Punana mesacostdlis Assemblage-Zone

Lower Upper

Not named

Ostracode zones in Virginia 

and northern North Carolina

EXPLANATION

Range in Cape Fear area

Range in Virginia-northern North Carolina, 

if different from range in Cape Fear area

Taxa having locally biostratigraphically 

diagnostic ranges

1 Bensonocythere aff B bradyi

i Bensonocythere sp C

3 Bensonocythere sp B

4 Actmocythereis captionis (large form)

5 Loxoconcha sp B

B Loxoconcha sp A

7 Hermanites ascitus

8 Maltella conradi

9 Paracythendea mucra

10 Penssocythendea sp C

11 Microcytherura minuta

12 Muellenna wardi

13 Punana caro/mensis

14 Bensonocythere gouldensis

15 Malzella evexa

1B Bensonocythere rugosa

17 Microcytherura similis

18 Radimella confragosa

19 Loxoconcha edentonensis

20 Microcytherura choctawhatcheensis

21 Ononma vaugham

22 Microcytherura sp C

23 Neocaudites vanabilis

24 Paracythendea altila

25 Neocaudites tnp/istnatus

2B Paracythendea edwardsi

27 Muellenna bassioumi

28 Punana mesacostalis

29 Bensonocythere whitei

30 Paracythendea rugosa

31 Microcytherura expanda

32 Echmocythereis leecreekensis

33 Muellenna sp B

34 Penssocythendea sp B

35 Bensonocythere sp A

3B Microcytherura sp B

37 Punana convoluta

38 Actmocythereis captionis

39 Paracytheroma stephensoni

40 Loxoconcha matagordensis

41 Palaciosa minuta

42 Caudites paraasymmetncus

43 Bensonocythere ncespittensis

44 Microcytherura sp 0

45 Paracythendea sp A

4B Malzella flondana

47 Punana sp A

48 Hulingsina sp N

49 Bensonocythere sp 0

50 Bensonocythere whitei (straight forml

Taxa also used by Hazel (19771 which permit

recognition of chronozones of ostracode

assemblage-zones

FIGURE 2.—Range chart for 50 ostracode species whose range-zones and concurrent-range-zones are useful in recognizing the chronozones of ostracode assemblage-zones in the Cape Fear Arch area. Solid lines indicate the ranges of 

species in the Cape Fear Arch area. Dashed lines indicate ranges of species in northern North Carolina and southern 

Virginia for species whose ranges are different in the two areas. The species are listed alphabetically in table 1 and 

are illustrated in figures 4-9.
B6 SHORTER CONTRIBUTIONS TO PALEONTOLOGY, 1979

more data on the geographic and stratigraphic distribution of ostracodes and to establish a more refined correlation of Atlantic Coastal Plain Neogene 

deposits.

The deposits considered in the present study span 

the interval from about 4.0 m.y. to 0.5 m.y. (million 

years) ago, a period encompassing the chronozone 

of the Orionina vaughani and Puriana mesacostalis 

Assemblage-Zones and younger deposits for which 

no ostracode zonation has been established (the 

Canepatch Formation). The presence of Paracytheridea edwardsi in coastal-plain deposits is indicative of this 3.5-m.y. interval.

The chronozone of the combined Orionina vaughani-Puriana mesacostalis Assemblage-Zones is 

suggested by the following species: Bensonocythere 

rugosa, Microcytherura minuta, M. similis, Radimella confragosa, Paracytheridea mucra, and Loxoconcha edentonensis. Microcytherura minuta and 

Paracytheridea mucra, however, are not known from 

the upper part of the Puriana mesacostalis Assemblage-Zone, and, similarly, Microcytherura similis 

is not known from the lower part of the Orionina 

vaughani Assemblage-Zone. Other species such as 

Malzella evexa, Bensonocy there gouldensis, Puriana 

carolinensis, and Muellerina wardi characterize this 

interval as well, but they are also known from the 

older Pterygocythereis inexpectata Assemblage-Zone 

in Virginia and northern North Carolina.

A reliable indicator of the chronozone of the Orionina vaughani Assemblage-Zone appears to be the 

concurrent-range-zone of Loxoconcha sp. A and 

Paracytheridea mucra, Microcytherura minuta, and 

Bensonocy there rugosa.

The chronozone of the Puriana mesacostalis AssemblageHZone was recognized by the range-zones of 

Microcytherura expanda, Puriana mesacostalis, and 

Muellerina bassiounii. However, Puriana mesacostalis, along with Palaciosa minuta and Paracytheridea rugosa, has been reported by Edwards 

(1944) from deposits assigned to the upper part of 

the Duplin Formation near Lumberton, N.C. Thus, 

they may have first appeared during the chronozone 

of the upper part of the Orionina vaughani Assemblage-Zone, or perhaps Puriana mesacostalis Assemblage-Zone deposits are present in this topographically high area, Additional sampling is necessary to 

clarify this problem. The concurrent-range-zones of 

several pairs of species also permit the recognition 

of the chronozone of the Puriana mesacostalis Assemblage-Zone (fig. 2).

In the Cape Fear Arch region, the chronozone for 

the lower part of the Puriana mesacostalis Assemblage-Zone is indicated by the concurrent-rangezones of Bensonocy there whitei, Puriana mesacostalis, Paracytheridea mucra, Muellerina bassiounii, 

Hermanites ascitus, Malzella conradi, and Microcytherura minuta.

The period encompassing the upper part of the 

Puriana mesacostalis Assemblage-Zone is characterized along the Atlantic Coastal Plain from northern 

North Carolina to Florida by the distinctive species 

Caudites paraasymmetricus.

Hazel (1971a, 1977) did not consider middle 01 

upper Pleistocene deposits of Virginia or North 

Carolina, and no ostracode zonation exists for this 

interval. Nevertheless, the ostracode assemblage of 

the Canepatch Formation is distinguished by the 

presence of Malzella floridana, Puriana sp. A, Bensonocythere sp. D, Hulingsina sp. N, and a distinctive form of Bensonocy there whitei.

LOCAL RANGE-ZONES

Today the Cape Hatteras region is a major zoogeographic boundary where many cryophilic and 

thermophilic species cease their equatorward and 

poleward expansion, respectively. Similarly, Pliocene and Pleistocene faunas from north and south of 

Cape Hatteras are distinct from one another, apparently because of paleooceanographic differences 

such as bottom-water temperature. Many cryophilic 

species, congeners of Cytheridea and Thaerocythere 

for example, are biostratigraphically diagnostic 

north of Cape Hatteras (Hazel, 1977) but are absent in the Cape Fear Arch region. Conversely, 

several species from the Cape Fear Arch region are 

absent from correlative deposits to the north, yet 

they are useful locally for correlation of lithostratigraphic units. These taxa, many of which are undescribed species, are indicated in figure 2.

Deposits of the Duplin Formation yielded several 

species that suggest a Yorktown age; these include 

Bensonocythere aff. B. bradyi, Bensonocy there sp. 

C, Bensonocythere sp. B, and a large form, Actinocythereis captionis. The cold-water species Loxoconcha sp. B characterizes this interval south of 

Cape Hatteras but is common in lower Pliocene to 

Holocene deposits to the north.

The chronozone of the Puriana mesacostalis Assemblage-Zone can be recognized locally by the presence of Muellerina sp. B, Perissocytheridea sp. B, 

Bensonocythere sp. A, and Microcytherura sp. B. 

Characteristic of the chronozone of the upper part 

of this assemblage-zone are Microcytherura sp. D 

and Bensonocythere ricespittensis. This latter spe-
OSTRACODE BIOSTRATIGRAPHY, NORTH AND SOUTH CAROLINA B7

cies ranges into the Orionina vaughani AssemblageZone north of Cape Hatteras.

The presence of Paracytheroma stephensoni and 

Loxoconcha matagordensis signifies the chronozone 

of the combined Puriana mesacostalis AssemblageZone and the unnamed zone representing the Canepatch Formation.

A middle Pleistocene (Canepatch) age is indicated 

in the Cape Fear Arch region by the first appearance 

of the following species: Malzella floridana, Puriana 

sp. A, Hulingsina sp. N, and Bensonocy'there sp. D. 

All these taxa except Bensonocy there sp. D are living on the shelf today.

The above discussion indicates the significance of 

paleoclimatic and paleooceanographic conditions on 

the geographic and stratigraphic distributions of 

ostracodes. Just as modern geographic ranges for 

ostracodes are often limited by bottom-water temperatures, so too, were there distinct zoogeographical 

faunal provinces during the Pliocene and Pleistocene. 

Moreover, the Pliocene and Pleistocene geographic 

distribution of extant species of the North Atlantic 

was quite different from that of today because of 

significant oceanographic changes. Studies of ostracodes from the late Pleistocene of the St. Lawrence 

lowlands (Cronin, 1977), the Norfolk Formation 

(Pleistocene) of Virginia (Valentine, 1971), and the 

Yorktown and Croatan Formations (Pliocene and 

Pleistocene) of Virginia and North Carolina (Hazel, 

1971b) have documented the distribution of many 

species during various periods in the Pliocene and 

Pleistocene and have permitted valuable paleoclimatic inferences to be made. Thus, any attempt to 

use ostracodes for regional correlation of Atlantic 

Coastal Plain deposits must necessarily include consideration of climatic effects on the distribution, 

both temporal and geographic, of particular species.

REGIONAL CORRELATION

On the basis of (1) the data presented above, (2) 

examination of material from deposits from the 

Chowan River assigned to the "Yorktown" by Hazel 

(1977), and (3) previously published data of Hazel 

(1971a, 1977, 1980), Edwards (1944), and others, 

a tentative correlation scheme for the Pliocene and 

Pleistocene of the central Atlantic Coastal Plain was 

developed. This chart (fig. 3) is a modification of 

figure 2 of Hazel (1977).

The Duplin Formation is in part Yorktown in age 

and can be correlated with the Orionina vaughani 

Assemblage-Zone. However, the upper part of the 

Duplin Formation has yielded several species characteristic of the Puriana mesacostalis AssemblageZone in Virginia and northern North Carolina (Edwards, 1944) ; hence, the precise placement of the 

upper part of the Duplin Formation is as yet 

uncertain.

Deposits at the Lee Creek mine, North Carolina, 

were assigned to the Yorktown and Croatan Formations by Hazel (1980). Whereas the Duplin Formation is in part equivalent to the Yorktown Formation, the Bear Bluff Formation of DuBar and others 

(1974) appears to be correlative with the lower part 

of the Croatan, and the Waccamaw Formation is 

equivalent to the upper part of the Croatan. Deposits 

on the Chowan River assigned to the "Yorktown" 

Formation (Hazel, 1971a, 1977) appear to be timeequivalents of the Bear Bluff Formation of DuBar 

and others (1974) and of at least the lower part of 

the Croatan, on the basis of the presence of species 

indicating the chronozone of the lower part of Puriana mesacostalis Assemblage-Zone. Deposits at Yadkin, Va., also referred to as "Yorktown" (Hazel, 

1977), may also be correlative with deposits of this 

late Pliocene interval.

The ostracode assemblage of the Canepatch Formation shows a distinctly modern character because 

several extant taxa appear for the first time in these 

deposits. Although no formal regional biostratigraphic zonation exists for middle and upper Pleistocene deposits, and, although many ostracode species have not yet been formally described, the present study indicates that ostracodes have great potential for local biostratigraphic correlation within 

the Pleistocene.

CONCLUSIONS

Detailed examination of ostracode assemblages 

from the Duplin, Bear Bluff, Waccamaw, and Canepatch Formations from the Cape Fear Arch region 

permit the following conclusions:

1. Ostracodes are useful biostratigraphic indicators 

in this region, as many species have well-defined, relatively short stratigraphic ranges and 

can be used for correlation of lithostratigraphic units.

2. The ostracode zonation of Hazel (1971a, 1977) 

can in part be extended south to the Santee 

River, S.C. The chronozones of the Orionina 

vaughani and the Puriana mesacostalis Assemblage-Zones can be recognized in the Cape 

Fear Arch region by the presence of diagnostic 

species.
B8 SHORTER CONTRIBUTIONS TO PALEONTOLOGY, 1979

Epoch

Late

Pleistocene

Middle

Pleistocene

Early 

Pleistocene

Pliocene

Late

Early

Ostracode

assemblage-zone

No formal 

zonation 

established

Purianc 

mesa 

wstalL

?

Upper

Lower

Orionina 

vaughani

Pterygocythereis

inexpectata

Virginia

"Yorktown" 

at Yadkin

Yorktown 

Formation

Mount Gould and

Colerain, N.C.

"York

i

town"

Yorktown 

Formation

Lee Creek

N.C.

Formation 'oatan 

o

Mine,

Upper

Lower

Yorktown 

Formation

Cape Fear

Arch area

Canepatch

Formation

of DuBar, 1971

Waccamaw 

Formation

Bear Bluff

Formation 

of DuBar and 

others, 1974

D 

For

uplin 

mation

FIGURE 3.—Tentative correlation chart for the Pliocene and Pleistocene deposits of southern Virginia, 

North Carolina, and northeastern South Carolina. Ostracode assemblage-zones are those used by 

Hazel (1971, 1977).
OSTRACODE BIOSTRATIGRAPHY, NORTH AND SOUTH CAROLINA B9

3. Some ostracode taxa that are rare to absent in 

Pliocene and Pleistocene deposits north of 

Cape Hatteras are locally useful as biostratigraphic indicators in the Cape Fear Arch 

region.

COLLECTION LOCALITIES

Locality 1.—Bank of Waccamaw River, 9.7 km east 

of intersection of South Carolina Routes 90 and 544 at Conway, S.C.; left off route 90 at 

Richardson's family house, 0.5 

km to river. Section is 225 m 

downstream from Richardson's 

house, near Tilly Lake. Type locality of Waccamaw Formation 

exposes 3 m of shelly sands from 

which four samples (55-58) 

were obtained.

Locality 2.—Outcrop on Intracoastal Waterway, 

Wampee 7.5-minute quadrangle, 

Horry County, S.C.; 6.7 km upstream from South Carolina 

Route 9 bridge over waterway. 

Sample 59 from Tagelus bed of 

Canepatch Formation, 3.3 m 

above peat bed. Sample 60, 0.6 m 

above sample 59, also Canepatch 

Formation. Samples 61 and 62 

from crossbedded coquina of 

Bear Bluff Formation.

Locality 3.—Northwest corner of Wampee 7.5- 

minute quadrangle, outcrops on 

Intracoastal Waterway at northeast end of Windy Hill Airstrip, 

Horry County, S.C., 0.3 km downstream from locality 2. (See DuBar, 1971, locality WA56, page 

21, for detailed lithostratigraphy.) Three samples (64-66) 

from the Waccamaw Formation 

and one sample (63) from the 

Canepatch Formation.

Locality 4.—Outcrops on Intracoastal Waterway 

at type locality of Canepatch 

Formation, Nixonville quadrangle, Horry County, S.C. (See 

DuBar, 1971, for details.) One 

sample (68) from MercenariaBryozoan facies.

Locality 5.—Right bank of Intracoastal Waterway, 5.5 km upstream from

west edge of Wampee 7.5-minute 

quadrangle, behind Myrtle Beach 

Shrine Club, Horry County, S.C. 

(Our locality 5 is loc. WA19 of 

DuBar, 1971.) Sample 70 from 

Canepatch Formation bed 5 of 

DuBar, 1971; samples 71 and 72 

from beds 4 and 2 of DuBar, 

1971, both from Waccamaw 

Formation.

Locality 6.—Pit on right side of North Carolina 

Route 130, 3.8 km north of the 

center of Old Dock, Columbus 

County, N.C. Four samples (73- 

76 in ascending order) from 

about 2 m of Waccamaw Formation.

Locality 7.—Walker's Bluff on west bank of Cape 

Fear River, 2.4 km northeast of 

North Carolina Route 87, about 

12.5 km northeast of Lisbon, 

Bladen County, N.C. Sample 79 

from lower 30 cm of Waccamaw 

Formation just above contact 

with Cretaceous; sample 80 from 

1.3 m above sample 79.

Locality 8.—Pierce Brothers pit, about 14.5 km 

southeast of Town Creek, Brunswick County, N.C. Pit is 6.4 km 

east of Mill Creek, about 1.6 km 

north of road that intersects 

North Carolina Route 87 at Mill 

Creek. Samples 84-82 (in ascending order) from 1 m of 

Waccamaw Formation; samples 

85 and 86 from spoil piles of 

material, stratigraphically below 

sample 84.

Locality 9.—Cape Fear River, 400 m downstream 

from Niels Eddy Landing and 

about 9.5 km northeast of Acme, 

Columbus County, N.C. sample 

88 from oyster bed near top, 

sample 87 from 0.3 m below top; 

sample 89 from 0.5 m below sample 87. All samples from Waccamaw Formation.

Locality 10.—Greenbank Landing on south bank 

of Cape Fear River, 12.5 km 

northeast of Acme, Brunswick 

County, N.C., 0.8 km upstream 

from confluence of Cape Fear 

River with Bryant Mile Creek.
BIO SHORTER CONTRIBUTIONS TO PALEONTOLOGY, 1979

Three samples (90-92) in ascending order) from 1 m of 

shelly sand of Waccamaw Formation.

Locality 11.—West part of pit, 1.6 km west of 

Acme, Columbus County, N.C., 

2.5 m of Waccamaw Formation 

exposed. Samples 97-95 (in ascending order) from lowermost 

meter; samples 93-94 (ascending order) from upper meter of 

blue-gray sand.

Locality 12.—Pit just east of Calabash, Brunswick 

County, N.C. Five samples (132- 

136) were taken. Two samples 

(132, 133) from the Bear Bluff 

Formation of DuBar (1971) and 

three samples (134-136) from 

the overlying Waccamaw Formation.

Locality 13.—Auger-drill-hole sample of Bear 

Bluff Formation, Hole H275 of 

DuBar (1971) from about 3.2 

km south of Lake Swamp, Bayboro 7.5-minute quadrangle, 

Horry County, S.C. One sample 

(H275). '

Locality 14.—Robeson family farm, 6.2 km southeast of intersection of Center 

Road and North Carolina Route 

87 at Tar Heel, Bladen County, 

N.C. About 2 m of Duplin Formation is exposed. Four samples 

(45-42 in ascending order) were 

examined from this section. Two 

additional samples, stratigraphically above the others, were examined, one sample (46) from 

50 m west of the section and 

the other (47) from 100 m west 

of section.

Locality 15.—Left bank of Lumber River, 2.4 km 

south of intersection of North 

Carolina Routes 211 and 74, 

14.0 km southeast of Lumberton, 

Robeson County, N.C. Three 

samples (50-48 in ascending 

order) were taken from, 1.3 m of 

Duplin Formation gray shelly 

sands, and one sample (51), from 

4 m above water level.

Locality 16.—Matthews family farm, 2.6 km southwest of Magnolia, N.C., and 2.9

km southwest of intersection of 

North Carolina Route 117 in 

Magnolia and road to Delway 

(Bladen County, Route 1003). 

Exposure in Natural Well 500 m 

behind house. One sample (41) 

was from a fossiliferous bed of 

the Duplin just above contact 

with Eocene.

Locality 17.—South face of the William Bird 

Ashley mine across South Carolina Route 378 from the Old 

Smokehouse about 5 km west of 

Con way, S.C., along Route 378. 

One sample was from the Bear 

Bluff Formation of DuBar 

(1971).

REFERENCES CITED

Akers, W. H., 1972, Planktonic Foraminifera and biostratigraphy of some Neogene formations, northern Florida and 

Atlantic Coastal Plain: Tulane Studies Geology and 

Paleontology, v. 9, no. 1-4, 139 p.

Akers, W. H., and Koeppel, P. E., [1974?], Age of some 

Neogene formations, Atlantic Coastal Plains, United 

States and Mexico, in Smith, L. A., and Hardenbol, Jan, 

eds., Symposium on calcareous nannofossils, Houston, 

Tex., 1973, Proceedings: Houston, Tex., Soc. Econ. 

Paleontologists and Mineralogists, Gulf Coast Sec., p. 

80-93.

Bloom, A. L., 1967, Pleistocene shorelines; a new test of 

isostasy: Geol. Soc. America Bull. v. 78, no. 12, p. 

1477-1494.

Brown, P. M., 1958, Well logs from the Coastal Plain of 

North Carolina; North Carolina Div. Mineral Resources 

Bull. 72, 68 p.

Clark, W. B., Miller, B. L., and Stephenson, L. W., 1912, The 

stratigraphy of the Coastal Plain of North Carolina; the 

geological history of the Coastal Plain of North Carolina: North Carolina Geol. Survey Bull. 3, p. 34-44, 

291-303.

Cooke, C. W., 1931, Seven coastal terraces in the southeastern States: Washington Acad. Sci. Jour. v. 21, no. 

21, p. 503-513.

————1932, Tentative correlation of American glacial chronology with the marine time scale: Washington Acad. 

Sci. Jour., v. 22, no. 11, p. 310-312.

————1936, Geology of the Coastal Plain of South Carolina: 

U.S. Geol. Survey Bull. 867, 196 p. 

-1943, Geology of the Coastal Plain of Georgia: U.S.

Geol. Survey Bull. 941, 121 p.

Cronin, T. M., 1977, Late-Wisconsin marine environments of 

the Champlain Valley (New York, Quebec) : Quaternary 

Research, v. 7, no. 2, p. 238-253.

Ball, W. H., 1892, 1903, Contributions to the Tertiary fauna 

of Florida, with especial reference to the Silex beds of 

Tampa and the Pliocene beds of the Caloosahatchie 

River: Wagner Free Inst. Sci. Philadelphia Trans., v. 3, 

pt. 2 (1892), p. 201-473; pt. 6 (1903), p. 1219-1654.
OSTRACODE BIOSTRATIGRAPHY, NORTH AND SOUTH CAROLINA Bll

————1898, A table of the North American Tertiary horizons, correlated with one another and with those of 

western Europe, with annotations: U.S. Geol. Survey 

18th Ann. Rept., pt. 2, p. 323-348.

DuBar, J. R., 1971, Neogene stratigraphiy of the lower 

Coastal Plain of the Carolinas: Atlantic Coastal Plain 

Geol. Assoc. 12th Ann. Field Conf., 1971, Guidebook, 

128 p.

DuBar, J. R., Johnson, H. S., Jr., Thorn, Bruce, and Hatchell, 

W. 0., 1974, Neogene stratigraphy and morphology, 

south flank of the Cape Fear Arch, North and South 

Carolina, in Oaks, R. Q., Jr., and DuBar, J. R., eds., 

Post-Miocene stratigraphy, central and southern Atlantic 

Coastal Plain: Logan, Utah, Utah State Univ. Press, 

p. 139-173.

Edwards, R. A., 1944, Ostracoda from the Duplin marl 

(upper Miocene) of North Carolina: Jour. Paleontology, 

v. 18, no. 6, p. 505-528.

Hazel, J. E., 1971a, Ostracode biostratigraphy of the Yorktown Formation (upper Miocene and lower Pliocene) of 

Virginia and North Carolina: U.S. Geol. Survey Prof. 

Paper 704, 13 p.

————1971b, Paleoclimatology of the Yorktown Formation 

(upper Miocene and lower Pliocene) of Virginia and 

North Carolina, in Oertli, H. J., ed., Colloque sur le 

paleoecologie des ostracodes, Pau, July 20-27, 1970: 

Centre Recherches Pau-SNPA [Soc. Natl. Petroles 

d'Aquitaine] Bull., v. 5 (Supp.), p. 361-375.

—1977, Distribution of some biostratigraphically diagnostic ostracodes in the Pliocene and lower Pleistocene of 

Virginia and northern North Carolina: U.S. Geol. Survey Jour. Research, v. 5, no. 3, p. 373-388. 

-1980, Age and correlation of the Yorktown (Pliocene)

and Croatan (Pliocene and Pleistocene) Formations at 

the Lee Creek, North Carolina open pit mine: Smithsonian Contr. Paleobiology. (In press.)

Howard, J. F., 1974, Neogene microfaunas in the Cape Fear 

Arch area, in Oaks, R. Q., Jr., and DuBar, J. R., eds., 

Post-Miocene stratigraphy, central and southern Atlantic 

Coastal Plain: Logan, Utah, Utah State Univ. Press, 

p. 123-138.

Pooser, W. K., 1965, Biostratigraphy of Cenozoic Ostracoda 

from South Carolina: Kansas Univ. Paleont. Contr. [38], 

Arthropoda, art. 8, 80 p.

Swain, F. M., 1952, Ostracoda from wells in North Carolina; 

pt. 1, Cenozoic Ostracoda: U.S. Geol. Survey Prof. Paper 

234-A, 58 p.

————1968, Ostracoda from the upper Tertiary Waccamaw 

Formation of North Carolina and South Carolina: U.S.. 

Geol. Survey Prof. Paper 573-D, 37 p.

Valentine, P. C., 1971, Climatic implication of a late Pleistocene ostracode assemblage from southeastern Virginia: 

U.S. Geol. Survey Prof. Paper 683-D, 28 p.

Winker, C. D., and Howard, J. D., 1977, Correlation of tectonically deformed shorelines on the southern Atlantic 

Coastal Plain: Geology, v. 5, no. 2, p. 123-127.

FIGURES 4-9
B14 SHORTER CONTRIBUTIONS TO PALEONTOLOGY, 1979

FIGURE 4.—Puriana, Radimella, and Malzella.

a, Puriana sp. A, female left valve, Canepatch Formation, sample 68, x 153, USNM 251996. b, Puriana carolinensis 

Hazel, male left valve, Duplin Formation, sample 48, x 157.5, USNM 251997. c, Puriana mesacostalis (Edwards), female left valve, Waccamaw Formation, sample 91, x 120.5, USNM 251998. d, Puriana convoluta Teeter, female left 

valve, Waccamaw Formation, sample 87, x 126, USNM 251999. e, Radimella confragosa (Edwards), female left valve, 

Waccamaw Formation, sample 75, x 126, USNM 252000. /. Malzella floridana (Benson and Coleman), female carapace, 

Canepatch Formation, sample 68, x 139.5, USNM 252001. g. Malzella evexa Hazel, female left valve, Waccamaw Formation, sample 91, x 108, USNM 252002. h. Malzella conradi (Howe and McGuirt), female left valve, Duplin Formation, sample 43, x 144, USNM 252003.
OSTRACODE BIOSTRATIGRAPHY, NORTH AND SOUTH CAROLINA B15

h
B16 SHORTER CONTRIBUTIONS TO PALEONTOLOGY, 1979

FIGURE 5.—Bensonocy there.

a, Bensonocythere gouldensis Hazel, female left valve, Waccamaw Formation, sample 90, x 90, USNM 252004. 6, Bensonocythere ricespittensis Hazel, male left valve, Waccamaw Formation, sample 135, X 112.5, USNM 252005. c, Bensonocythere rugosa Hazel, male left valve, Duplin Formation, sample 47, x 126, USNM 252006. d, Bensonocythere sp. 

A, female left valve, Bear Bluff Formation, sample 133, x 112.5, USNM 252007. e, Bensonocythere sp. C, female left 

valve, Duplin Formation, sample 47, X 112.5, USNM 252008. /, Bensonocythere sp. D, female left valve, Canepatch 

Formation, sample 68, X 126, USNM 252009. g, Bensonocythere whitei (Swain) s.s., female left valve, Waccamaw 

Formation, sample 135, x 90, USNM 252010. h, Bensonocythere whitei (Swain) (straight form), male left valve, Canepatch Formation, sample 68, x H2.5, USNM 252011.
OSTRACODE BIOSTRATIGRAPHY, NORTH AND SOUTH CAROLINA B17
B18 SHORTER CONTRIBUTIONS TO PALEONTOLOGY, 1979

FIGURE 6.—Bensonocythere, Muellerina, Hermanites, and Actinocythereis.

a, Bensonocy there aff. B. bradyi Hazel, male right valve, Duplin Formation, sample 45, X 90, USNM 252012. b, Bensonocythere sp. B, female right valve, Duplin Formation, sample 47, X 112.5, USNM 252013. c, Muellerina ivardi Hazel, 

male left valve, Waccamaw Formation, sample 79, x 135, USNM 252014. d, Muellerina sp. B, male left valve, Waccamaw Formation, sample 88, x 120.5, USNM 252015. e, Muellerina bassiounii Hazel, male left valve, Duplin Formation, sample 49, x 135, USNM 252016. /, Hermanites ascitus Hazel, female carapace, Duplin Formation, sample 45, 

X 144, USNM 252017. g, Actinocythereis captionis Hazel, female right valve, Waccamaw Formation, sample 76, X 117, 

USNM 252018. h, Actinocythereis captionis Hazel (large form), female right valve, Duplin Formation, sample 43, X 

103.5, USNM 252019.
OSTRACODE BIOSTRATIGRAPHY, NORTH AND SOUTH CAROLINA B19
B20 SHORTER CONTRIBUTIONS TO PALEONTOLOGY, 1979

FIGURE 7.—Microcytherura and Paracytheroma,

a, Microcytherura sp. C, female right valve, Canepatch Formation, sample 68, x 135, USNM 252020. b, Microcytherura sp. B, female right valve, Waccamaw Formation, sample 76, x 112.5, USNM 252021. c, Microcytherura choctawhatcheensis (Puri), female right valve, Waccamaw Formation, sample 87, x 112.5, USNM 252022. d, Microcytherura similis (Malkin), female right valve, Waccamaw Formation, sample 87, x 157.5, USNM 252023. e, Microcytherura sp. D, female? right valve, Waccamaw Formation, sample 87, X 180, USNM 252024. /, Microcytherura expanda 

Hazel, male? right valve, Waccamaw Formation, sample 73, x 112.5, USNM 252025. g, Microcytherura minuta Hazel, 

female right valve, Duplin Formation, sample 48, x 135, USNM 252026. h, Paracytheroma stephensoni (Puri) female 

left valve, Waccamaw Formation, sample 83, x 135, USNM 252027.
OSTRACODE BIOSTRATIGRAPHY, NORTH AND SOUTH CAROLINA B21
B22 SHORTER CONTRIBUTIONS TO PALEONTOLOGY, 1979

FIGURE 8.—Paracytheridea, Orionina, Neocaudites, Caudites, and Hulingsina.

a, Paracytheridea mucra Edwards, female right valve, Bear Bluff Formation, sample H 275, X 117, USNM 252028. 

b, Paracytheridea rugosa Edwards, female right valve, Duplin Formation, sample 87, X 126, USNM 252029. c, Paracytheridea sp. A, male? right valve, Canepatch Formation, sample 68, x 144, USNM 252030. d, Paracytheridea edwardsi Hazel, male right valve, Canepatch Formation, sample 68, X 135, USNM 252031. e, Orionina vaughani (Ulrich and 

Bassler), female carapace, Duplin Formation, sample 48, X 90, USNM 252032. /, Paracytheridea altila Edwards, female 

right valve, Waccamaw Formation, sample 81, x 130.5, USNM 252033. g, Neocaudites triplistriatus (Edwards) s.l., 

elongate form, male carapace, Duplin Formation, sample 50, X 117, USNM 252034. h, Neocaudites variabilis Hazel, 

male carapace, Waccamaw Formation, sample 84, x 117, USNM 252035. i, Caudites paraasymmetricus Hazel, female 

carapace, Waccamaw Formation, sample 74 X 108, USNM 252036. j. Hulingsina sp. N, female? left valve, Canepatch 

Formation, sample 68, x 135, USNM 252037.

B24 SHORTER CONTRIBUTIONS TO PALEONTOLOGY, 1979

FIGURE 9.—Loxoconcha, Perissocytheridea, Echinocythereis, and Palaciosa.

a, Loxoconcha sp. B, male left valve, Duplin Formation, sample 50, x 112.5, USNM 252038. b, Loxoconcha sp. A, female 

left valve, Duplin Formation, sample 48, x 135, USNM 252039. c, Loxoconcha matagordensis (Swain), female left 

valve, Waccamaw Formation, sample 76, x 144, USNM 252040. d, Loxoconcha edentonensis Swain, female left valve, 

Waccamaw Formation, sample 76, x 126, USNM 252041. e, Perissocytheridea, sp. C, female left valve, Duplin Formation, sample 48, x 148.5, USNM 252042. /, Echinocythereis leecreekensis Hazel, male? left valve, Waccamaw Formation, sample 73, x 72, USNM 252043. g, Perissocytheridea sp. B, female left valve, Canepatch Formation, sample 60, x 

153, USNM 252044. h, Palaciosa minuta (Edwards), female left valve, Waccamaw Formation, sample 81, x 171, 

USNM 252045.


Miocene Mollusks of the Topsy Formation, 

Lituya District, Gulf of Alaska 

Tertiary Province, Alaska

By LOUIE MARINCOVICH, JR.

SHORTER CONTRIBUTIONS TO PALEONTOLOGY, 1979

GEOLOGICAL SURVEY PROFESSIONAL PAPER 1125-G

CONTENTS

Page

Abstract ____________________________________________ Cl

Introduction ________________________________________ 1

Acknowledgments _________________________________ 2

Faunal composition _____________________„_____________ 3

Age and correlation _________________________________________ 3

Paleoecology ________________________________________________ 5

Water depth ___________________________________ 5

Water temperature __________________________________________ 5

Systematic paleontology ___________________________________ 7

Fossil locality descriptions ____________________________________ 13

References cited __________________________________________________ 13

ILLUSTRATIONS

Page

FIGURE 1. Distribution of the Topsy Formation and other Cenozoic marine sedimentary and volcanic rocks in

the Lituya District, Gulf of Alaska Tertiary Province _________________________ C2

2. Known stratigraphic ranges in Pacific Northwest and Gulf of Alaska Tertiary Provinces of selected

Topsy Formation mollusks _________________________________________ 3

3-30. Photographs of fossil mullusks ______________________________________________ 7

3. Periploma (Aelga) besshoense (Yokoyama). 

4-6. Macoma albaria (Conrad). 

7-9. Macoma aff. M. twinensis Clark.

10. Macoma incongrua (von Martens).

11. Spisula addicotti Kanno.

12. Nuculana (Saccella) sp. 

13-14. Macoma aff. M. albaria (Conrad). 

15-16. Lucinoma acutilineata (Conrad).

17. Thyasira cf. T. disjuncta (Gabb). 

18-19. Acila (Truncacila) taliaferroi Clark. 

20-21. Fusitriton oregonensis (Redfield). 

22-23. Calliostoma sp.

24. IColus sp.

25. Natica (Cryptonatica) clausa Broderip and Sowerby.

26. Natica (Cryptonatica) oregonensis (Conrad).

27. tNeptunea (Neptunea) plafkeri Kanno. 

28-30. Neptunea (Sulcosipho) cf. N. (S.) tabulata (Baird).

TABLE

Page

TABLE 1. Fossils of the Topsy Formation ________________________________—__————————— C3

in

SHORTER CONTRIBUTIONS TO PALEONTOLOGY, 1979

MIOCENE MOLLUSKS OF THE TOPSY FORMATION, LITUYA DISTRICT, 

GULF OF ALASKA TERTIARY PROVINCE, ALASKA

By LOUIE MARINCOVICH, JR.

ABSTRACT

The Topsy Formation in the Lituya district of the Gulf 

of Alaska Tertiary Province contains a molluscan fauna of 

Newportian age (late early Miocene to early middle Miocene) that correlates with similar faunas in the Pacific 

Northwest and in the lower part of the Yakataga Formation 

at Cape Yakataga, in the nearby Yakataga district. Topsy 

mollusks with living representatives or homologues suggest 

deposition in cool-temperature water at inner sublittoral 

depths of about 20 to 50 m.

INTRODUCTION

Sedimentary rocks of the Topsy Formation occur 

in the southeastern part of the Gulf of Alaska 

Tertiary Province (fig. 1), an area which extends 

about 600 km along the arcuate coast of the eastern 

Gulf of Alaska from the Katalla district in the west 

to the Lituya district in the east (Plafker, 1967). In 

this province, the Poul Creek and Yakataga Formations are the principal marine sedimentary units and 

together consist of upper Eocene to Holocene deposits with an aggregate thickness of about 6,100 

to 7,600 m (Plafker, 1971). The Yakataga Formation alone consists of about 5,000 m of lower Miocene to Holocene marine deposits that preserve a 

continuous record of localized glacial conditions in 

this area of the North Pacific (Plafker and Addicott, 1976). The Lituya district (fig. 1), centered 

on Lituya Bay, contains the southeasternmost outcrops of Tertiary marine sedimentary rocks in the 

Gulf of Alaska region and is the only area in which 

the Topsy Formation occurs.

The Topsy Formation consists of marine siltstone 

and sandstone that crop out between Lituya Bay 

and Icy Point (fig. 1) and that extensively underlie 

foothills of the Fairweather Range for about 40 km 

adjacent to the Gulf of Alaska shoreline. Outcrops 

are generally small and isolated owing to cover by

dense vegetation and glaciers. Persistent rain and 

fog in summer also limit access to Topsy exposures. 

Because discontinuous outcrops and structurally 

complex geology in this area preclude reliable lithologic correlations with other formations in this 

region and because no well-preserved, age-diagnostic 

fossils have been reported before from these strata, 

the age and depositional environment of the Topsy 

have been subjects for speculation. Molluscan fossils 

collected in 1975 now shed light on the age and depositional environment of the Topsy and suggest 

correlations with sedimentary rocks elsewhere in 

the Gulf of Alaska Tertiary Province and in the 

Pacific Northwest (Oregon and Washington). Benthic foraminifers (Rau and others, 1977) or other 

microfossils have not been found in Topsy strata.

The outcrop extent of the Topsy Formation shown 

in figure 1 is modified from that previously published (Plafker, 1967). Strata adjacent to the coastline immediately north of Icy Point, which were 

formerly assigned to the Yakataga Formation, are 

now included in the Topsy Formation, on the basis of 

1975 fieldwork done by George Plafker and Travis 

Hudson. The Topsy does not occur on Cenotaph 

Island in Lituya Bay (fig. 1), so sand dollar echinoids reported from the Topsy by Wagner (1974) 

should be attributed to the Yakataga Formation.

Sedimentary rocks now included in the Topsy Formation were first discriminated from those of the 

Yakataga Formation by Miller (1953, 1961), who 

considered them to be, in part, stratigraphically 

equivalent to volcanic rocks on Cenotaph Island and 

on the southern margin of Lituya Bay (fig. 1). 

Sparse and poorly preserved invertebrates in these 

rocks indicated a Tertiary age, and Miller (1961) 

thought that they were likely of Miocene age because of their conformable relation with overlying

Cl
C2 SHORTER CONTRIBUTIONS TO PALEONTOLOGY, 1979

58°45'—

58°30'—

' FAIRWEATHER 

GLACIER .

_ Topsr Cenotaph Format.on Volcanics

138 137°

FIGURE 1.—Distribution of the Topsy Formation and other Cenozoic marine sedimentary and volcanic rocks in the Lituya 

district, Gulf of Alaska Tertiary Province (inset). Geology modified from Miller (1961) and Plafker (1967).

beds thought to contain late Miocene fossils. A tentative Miocene age was also assigned to these rocks 

by MacNeil and others (1961). Plafker (1967) 

named the Topsy Formation and Cenotaph Volcanics, noting that the Topsy consists of about 365 

m of hard calcareous siltstone and sandstone that 

intertongue with and, in part, conformably overlie 

the Cenotaph Volcanics. Plafker (1967) did not 

specify an age for the Topsy strata but assigned the 

Cenotaph Volcanics an age of "post-early Oligocene(?) to pre-middle Miocene," thereby implying 

an age of about late Oligocene to early Miocene or

younger for the Topsy. Later, Plafker (1971) considered most of the Topsy Formation to be Miocene, 

possibly containing beds as old as middle Oligocene 

and as young as middle Miocene. Notes on the molluscan fauna by Marincovich (1976a, b), from which 

the present report is expanded, suggested an early 

or middle Miocene age for the Topsy Formation.

ACKNOWLEDGMENTS

Helpful discussions of molluscan taxonomy and 

geologic field relations were held with Warren 0.
MIOCENE MOLLUSKS OF THE TOPSY FORMATION, LITUYA DISTRICT, ALASKA C3

Addicott and George Plafker, U.S. Geological Survey. Richard C. Allison, University of Alaska, critically read this work and provided valuable unpublished information on Alaskan Tertiary mollusks. 

Catherine Ariey, Atlantic Richfield Co., also provided 

useful data on molluscan biostratigraphy at Cape 

Yakataga, based on her unpublished thesis work. 

Kenji Sakamoto, U.S. Geological Survey, photographed the specimens.

FAUNAL COMPOSITION

No well-preserved molluscan taxa have been reported previously from the Topsy Formation. The 

present collections, made in 1975, consist of 20 taxa, 

consisting of 8 gastropods and 12 bivalves. Four 

additional bivalves tentatively assigned generic or 

specific names are too poorly preserved for confident 

identification. The preponderance of bivalve taxa 

and individuals over gastropods (table 1) is usual 

for Gulf of Alaska Cenozoic faunas, including 

modern ones. The Topsy genera are each represented by a single species except for Macoma, Neptunea, and Natica.

Seven of the bivalve taxa are represented by articulated and closed specimens, suggesting little or no 

post mortem transport of these faunal elements. 

However, the known Topsy molluscan taxa probably 

represent a small fraction of the original fauna. The 

absence of fossils from most outcrops of the Topsy

TABLE 1.—Fossils of the Topsy Formation

[Number of specimens given for each entry; A, articulated bivalve; F, fragment]

Species Localities

M6528 M6527 M6526 M6525

Gastropods

Calliostoma sp. —— ———————————— ——— ———— —— - 1

Turbinidae ———————————————————————————— IF

Nation (Cryptonatica) alausa Broderip and Sowerby — 1

Natica (Cryptonatica) oregonensis (Conrad) -—————- ——

Fusitriton oregonensis (Redfield) - ———— ————— — - 1

?Neptunea (Neptunea) plafkeri Kanno —————————— —

Neptunea (Sulcosipho) cf. N. (S. ) ta.bu.lata (Baird) — —

?Colu8 sp. ———— ——— ~ ——————— —————— —— —— —— IF

Bivalves

Acila (Trunaacila) taliaferroi Clark ———————- 1

Acila (Trunaacila) sp. ——— —— ————— ————— ——

Nuaulana l?Saccella) sp. - — ———————————————• 

?Chlamys sp. ———— ———— —— ———— ----————————•

Lucinoma aautilineata (Conrad) - —— — ————— —

Thyasira cf. T. disjuncta (Gabb) - —— ——————•

Macoma albaria (Conrad) —— — ——— — ——— — — ——— —

Macoma aff. M. albaria (Conrad) ———————————— 1

Macoma inaongrua (von Martens) ——— — — — — — — — 2

Macoma cf. M. ineongrua (von Martens) — ——— -- —— - 1A 

Macoma aff. M, twinensis Clark ——— — ——— ~———— 1,4A 

Spieula addicotti Kanno —— ——— — — ————— — ——— 1

?Spisula sp. ——————————————————————————— IF 

Periploma (Aelga) besshoense (Yokoyama) -—————— 1 

?Periploma sp. - — — — ——— —————— ————— ——— -- 1A.2F

Mya sp. ————-———————————————————————————— ——

1

IF

1 14A.3F

2.1A

1.4A 

7.3A

Sand dtfllar echinoid IF

Fish vertebra

contrasts sharply with the known abundance of 

faunas from coeval strata of the Yakataga Formation. This absence suggests either an original lowdiversity fauna or post mortem destruction of fossils by wave and current action. The paucity of observed fossils also could be an artifact of collecting, 

considering the difficulties imposed by topography, 

and weather in the Lituya district.

AGE AND CORRELATION

Some of the Topsy mollusks are known in Tertiary 

strata of the Pacific Northwest. The overlapping 

stratigraphic ranges of these species (fig. 2), as they 

are known in the Pacific Northwest, place the Topsy 

fauna within the Newportian Stage of Addicott

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FIGURE 2.—Known stratigraphic ranges in Pacific Northwest 

and Gulf of Alaska Tertiary Provinces of selected Topsy 

Formation mollusks. Occurrences in Alaskan formations 

(Pouls Creek, Yakataga, and so-called Narrow Cape Formation) are based on literature reports and unpublished 

studies of C. A. Ariey and R. C. Allison. Formations of 

first and last occurrences as well as other relevant stratigraphic occurrences are shown. Pacific Northwest molluscan stages from Addicott (1976b), as modified by Allison 

(1976). The Topsy Formation is inferred to be of Newportian age.
C4 SHORTER CONTRIBUTIONS TO PALEONTOLOGY, 1979

(1976b). When first proposed, the Newportian Stage 

was assigned exclusively to the middle Miocene, encompassing the whole of that isubseries (Addicott, 

1976b). Subsequently, Allison (1976) reinterpreted 

the stage boundaries by relying more heavily on 

Berggren and Van Couvering's (1974) planktonic 

microfossil correlations with European Cenozoic 

strata. He concluded that the Newportian Stage is 

of late early Miocene and early middle Miocene age 

(fig. 2). In terms of California benthic foraminiferal 

stages, this interval includes the upper half of the 

Saucesian Stage and the overlying Relizian and 

Luisian Stages (Allison, 1976). Allison's interpretation of the Newportian Stage is used here in assessing the age of the Topsy molluscan fauna. However, 

the work of relating Alaskan Cenozoic faunas to 

biostratigraphic schemes proposed for other regions 

is still in its early stages, and major changes in the 

inferred age relations of Alaskan faunas may yet 

occur.

Ironically, because Cenozoic molluscan faunal 

composition and biostratigraphy in the Gulf of 

Alaska region are not yet well known, correlations 

from the Topsy fauna to other Gulf of Alaska 

faunas are more speculative than are those to Tertiary faunas in the Pacific Northwest. However, the 

basal part the Yakataga Formation at Cape Yakataga (fig. 1) bears a molluscan fauna of Newportian 

age (Kanno, 1971; Plafker and Addicott, 1976; Allison, 1976; and Ariey 1978a, b) and thus is approximately coeval with the Topsy Formation. Both 

Neptunea species in the Topsy, N. plafkeri (questionably identified) and N. cf. N. tabulata of Kanno 

(1971), have previously been reported only in the 

Yakataga Formation, at several localities (Nelson, 

1974). Their earliest reported occurrences are in 

the lower part of the Yakataga Formation at Cape 

Yakataga (Clark, 1932; Kanno, 1971; Nelson, 1974), 

although they evidently occur in the underlying Poul 

Creek Formation at that location (Ariey, 1978a). 

The earliest occurrence of Fusitriton oregonensis in 

the northeast Pacific, or what may be a closely 

allied or new species (Smith, 1970), is also at Cape 

Yakataga. Smith (1970, p. 492) reported specimens 

of "Fusitriton sp. ? aff. F. oregonensis" from either 

the Poul Creek or Yakataga Formations. More recent collecting of the Cape Yakataga section (Ariey, 

1978a) showed F. oregonensis missing in the upper 

part of the Poul Creek Formation but present in the 

stratigraphically highest Newportian fauna (early 

middle Miocene) and in the immediately overlying 

Wishkahan fauna (late middle Miocene to late Miocene) of the basal Yakataga Formation (fig. 2).

Lucinoma acutilineata and Macoma albaria have 

their highest stratigraphic occurrences in the Astoria Formation of southwestern Washington and of 

the Newport embayment of coastal Oregon, in 

faunas of Newportian age (Addicott, 1976b). Macoma albaria is reported in faunas no older than Pillarian in the Clallam Formation in northwestern 

Washington and the Nye Mudstone of the Newport 

area in Oregon (Moore, 1963; Addicott, 1976a). In 

the Pacific Northwest, Natica clausa first occurs in 

Newportian faunas of the Astoria Formation. Its 

reported first occurrence in Alaska is in lower Miocene strata in the upper Poul Creek Formation 

(Marincovich, 1977), and it has since been recognized in the Juanian fauna of the so-called Narrow 

Cape Formation on Sitkinak Island in the western 

Gulf of Alaska (R. C. Allison, oral commun., 1977). 

Natica oregonensis was formerly known only in the 

Pacific Northwest, where it ranges from the Pillarian (Nye Mudstone) to Wishkahan (Empire 

Formation) ; it has been questionably identified in 

the Newportian fauna of the Narrow Cape Formation on Kodiak Island in the western Gulf of Alaska 

(R. C. Allison, oral commun., 1977).

The single Topsy species with Asian affinities is 

Periploma besshoense, which is known in Eocene or 

Oligocene to upper Miocene strata in Japan (Kanno, 

1971; Hatai and Nisiyama, 1952). This species has 

a variable shell outline in Japanese faunas, and 

Kanno (1971) noted the presence of two* distinct 

morphologic forms of P. besshoense in strata at 

Cape Yakataga. Kanno (1971) collected the typical 

Japanese form, nearly circular in outline, in the 

upper part of the Poul Creek Formation and a more 

elongate and somewhat rostate form in the overlying 

Yakataga Formation. The elongate form in the 

lower part of the Yakataga Formation is also present in the Topsy (fig. 3), so if Kanno's (1971) tentative conclusions are correct, this form of P. besshoense would strengthen correlation of the Topsy 

Formation with the lower Yakataga Formation at 

Cape Yakataga.

In summary, the Topsy molluscan fauna correlates with Newportian faunas at Cape Yakataga and 

in Washington and Oregon. Further, the occurrence 

together of Fusitriton oregonensis, Macoma albaria, 

and Lucinoma acutilineata suggests probable assignment of the Topsy to the upper Newportian Stage 

of latest early Miocene and early middle Miocene 

age. This interval is approximately equivalent to the 

Relizian and Saucesian Stages of California benthic 

foraminiferal terminology, based on interpretations
MIOCENE MOLLUSKS OF THE TOPSY FORMATION, LITUYA DISTRICT, ALASKA C5

of Pacific Northwest molluscan stages by Allison 

(1976).

PALEOECOLOGY

WATER DEPTH

The Topsy molluscan fauna represents a shallow, 

cool-temperature marine environment. The deepburrowing bivalve Mya lives between the intertidal 

zone and 50 m depth in the northeastern Pacific 

(Keen and Coan, 1974), and large individuals such 

as the Topsy specimen (52 mm in height, incomplete) dwell under optimal growth conditions in the 

shallower portion of this range. The bivalve genera 

Spisula and Periploma also have narrow bathymetric ranges in the modern northeastern Pacific; 

Spisula is known from the intertidal zone to 100 m 

on sand, and Periploma is known between 20 and 

90 m (Burch, 1945; Keen and Coan, 1974). The 

modern homologue of Lucinoma acutilineata, L. annulata (Reeve, 1850), lives in depths of 20 to 800 

m and occurs abundantly, as in the Topsy, in the 

shallowest part of its range. Thyasira disjuncta, 

tentatively identified in the Topsy, is reported in 

water as shallow as 10 m or less in the Gulf of 

Alaska (Kanno, 1971) but only between 150 and 

750 m off of western Canada (Bernard, 1972). Noting the occurrence of T. disjuncta at 10 m or less in 

the Gulf of Alaska but no shallower than 60 m off 

of Japan, Kanno (1971) speculated that depth distribution is a function of water temperature for this 

species, which is further suggested by Bernard's 

relatively deep-water records for western Canada.

All of the Topsy gastropod taxa are known in 

shallow marine habitats. Fustriton oregonensis lives 

between the southern Bering Sea and San Diego, 

Calif., from the intertidal zone to 2,370 m. It 

occurs in increasingly deep water 'southward, reflecting its preference for cool water. From Washington 

northward, it is found intertidally except where 

winter sea ice occurs and to depths of 430 m; it has 

been observed spawning in the intertidal zone 

(Smith, 1970). Natica clausa has its depth distribution strongly controlled by water temperature, so it 

may occur as shallowly as 9 m in Arctic seas but 

only below 150 m off southern California (Marincovich, 1977). The closely related species Natica oregonensis is extinct and known from Oregon and 

Washington in Neogene faunas of shallow to moderate depth (Moore, 1963; Marincovich, 1977). Calliostoma ranges from the intertidal zone to 915 m in 

the modern northeastern Pacific (Keen and Coan, 

1974) and is most common in depths of about 70 m

or less, commonly associated with kelp beds (Burch, 

1946; McLean, 1969).

In summary, mollusks of the Topsy Formation collectively suggest water depths of about 20 to 50 m. 

Even though some taxa are known to range into 

shallower or greater depths, a range of 20 to 50 m 

is the broadest interval necessary to account for the 

presence of all of the Topsy mollusks. None of the 

Topsy taxa or their modern counterparts are known 

to live exclusively in greater or lesser depths. The 

fact that most of the bivalves are articulated indicates that post mortem transport had little or no 

effect on species composition of the Topsy fauna.

WATER TEMPERATURE

Cool-temperate water temperatures similar to 

those of the modern open coastline of the Lituya 

district are indicated by the Topsy mollusks, although few reliable data are known on natural temperature tolerances for their living representatives. 

Some of the species, such as Fusitriton oregonensis, 

Natica clausa, and Thyasira disjuncta, have geographic ranges extending as far south as California 

or Baja California. However, such species inhabit 

low latitudes by living in cold bottom-water below 

the influence of warmer surface-water masses. They 

inhabit inner sublittoral areas only when surface 

waters are of cool-temperate to arctic temperatures. 

All of the Topsy species still living or with modern 

homologues include the Lituya district within their 

geographic ranges.

The bivalve genus Acila, represented in the Topsy 

fauna by Acila (Truncacila) taliaferroi, can survive 

in temperate water ranging from about 4.4°C to 

21.1°C and Truncacila favors cool-temperate habitats (Schenck, 1936), presumably ranging from 

about 4.4°C to 12.7°C. The lowest temperature in 

which living Truncacila have been recorded is 3.6°C 

(Schenck, 1936). Living Acila are not known below 

a depth of 1,465 m, nor are they known in the intertidal zone (Schenck, 1936).

Fusitriton oregonensis lives in temperate to cold 

water along the North Pacific rim from Japan to 

southern California in depths to 2,370 m. It has 

been observed in the intertidal zone from Puget 

Sound, Wash., to southeastern Alaska and has been 

collected from depths as shallow as 18 m in the 

southern Bering Sea and 9 m in the Gulf of Alaska 

(Smith, 1970). Sbuthwestward from the Bering Sea 

and south of Puget Sound, it lives in progressively 

greater depths. This species has also' been reported 

in temperatures of 7°C to 11°C in Puget Sound and
C6 SHORTER CONTRIBUTIONS TO PALEONTOLOGY, 1979

30
MIOCENE MOLLUSKS OF THE TOPSY FORMATION, LITUYA DISTRICT, ALASKA C7

FIGURES 3. Periploma (Aelga) besshoense (Yokoyama). 

USNM 250860. Height 33.4 mm, length 54.2 

mm.

4-6. Macoma albaria (Conrad). USNM 250862. 

Height 16.5 mm, length 22.1 mm.

4. Right valve.

5. Dorsal aspect.

6. Left valve. 

7-9. Macoma aff. M. twinensis Clark.

7. USNM 250866, right valve, height 12.7 

mm, length 20.0 mm.

8. USNM 250865, left valve, height 17.5 mm, 

length 23.4 mm.

9. USNM 250865, dorsal aspect.

10. Macoma incongrua (von Martens). USNM 

250864. Right valve, height 14.7 mm, length 

19.1 mm.

11. Spisula addicotti Kanno. USNM 250871, right 

valve, height 14.6 mm, length 22.7 mm.

12. Nuculana (Saccella) sp. USNM 250867, right

valve, height 11.3 mm, length 17.0 mm. 

13-14. Macoma aff. M. albaria (Conrad). USNM 

250863.

13. Left valve, height 15.3 mm, length 24.8 

mm.

14. Dorsal aspect.

15-16. Lucinoma acutilineata (Conrad). USNM 250861. 

Specimen distorted.

15. Left valve, height 40.0 mm, length 44.4 

mm.

16. Right valve.

17. Thyasira cf. T. disjuncta (Gabb). USNM 

250870, left valve, height 36.5 mm, length 36.2 

mm.

18-19. Acila (Truncacila) taliaferroi Clark. USNM 

250868, height 15.8 mm, length 17.3 mm.

18. Dorsal aspect.

19. Right valve.

20-21. Fusitriton oregonensis (Eedfield). USNM 

250874, height 39.7 mm, diameter 22.5 mm. 

Specimen distorted.

20. Apertural view.

21. Backside view, showing spiral sculpture. 

22-23. Calliostoma sp. USNM 250872, height 22.8 mm, 

diameter 26.2 mm. Specimen distorted.

22. Apertural view.

23. Backside view, showing fine spiral sculpture.

24. tColus sp. USNM 250876, height 27.6 mm, diameter 16.2 mm. Specimen distorted and worn.

25. Natica (Cryptonatica) clausa Broderip and 

Sowerby. USNM 250869, height 10.4 mm, diameter 10.0 mm.

26. Natica (Cryptonatica) oregonensis (Conrad). 

USNM 250873, height 11.1 mm, diameter 8.0 

mm.

27. INeptunea (Neptunea) plafkeri Kanno. USNM 

250875, height 54.0 mm. diameter 36.3 mm. 

Apertural view, specimen distorted.

28-30. Neptunea (Sulcosipho) cf. N. (S.) tabulata 

(Baird). USNM 250877, height 42.3 mm, 

greatest diameter 39.0 mm, least diameter 

22.9 mm. Specimen distorted.

28. Oblique apertural view, showing spiral 

sculpture.

29. Apertural view, showing shoulder tabulation.

30. Backside view, showing spiral sculpture.

in waters less than 8°C off of southern California 

(Valentine and Emerson, 1961).

Modern surface-water temperatures in the eastern 

Gulf of Alaska range from monthly averages of 6.7 °C 

in February to 14.4°C in August (LaViolette and 

Seim, 1969). Nearshore marine temperatures significantly different from those of the modern Lituya 

district are not required to account for the Topsy 

fauna.

SYSTEMATIC PALEONTOLOGY

Acila (Truncacila) taliaferroi Clark, 1932 

Figures 18-19

This species is characterized by its moderate size 

and relatively high shell, somewhat inflated valves, 

nearly vertical axis of bifurcation of its fine, subdued radial sculpture and by the shape of its escutcheon. Interior features of the valves are unknown.

Acila (Truncacila) taliaferroi is most similar to 

A. (T.) conradi (Meek, 1864), which occurs in the 

lowermost Pillarian and Newportian Stages of the 

Pacific and in coeval beds in California, and to A. 

(T.) empirensis Howe, 1922, known from the Wishkahan and Graysian( ?) Stages of the Pacific Northwest. Acila taliaferroi and A. conradi are identical 

in shell outline and inflation of their valves. However, A. taliaferroi may be distinguished by its 

smaller size (A. conradi attains a height of 21.7 

mm; Schenck, 1936), relatively greater height, less 

elongate escutcheonal area, and distinctly more vertical axis of bifurcation of the radial ribs. The last 

two features are most useful for quickly separating 

specimens of the two species. Both species show a 

band of obsolete radial ribbing along the adult ventral shell margin, but the occurrence of secondary 

bifurcation of the radial ribs is more pronounced on 

A. conradi than on A. taliaferroi.

Compared to A. empirensis, A. taliaferroi is 

smaller (the former species is as much as 19.3 mm 

high and 25.9 mm long; Schenck, 1936), has a more 

acutely rounded anterior extremity and finer radial 

sculpture standing in much lower relief. In addition, 

the angle of bifurcation of the radial sculpture is 

more vertical in A. taliaferroi and the secondary 

bifurcation is less pronounced than in A. empirensis. 

Undistorted individuals of A. taliaferroi usually have
C8 SHORTER CONTRIBUTIONS TO PALEONTOLOGY, 1979

more inflated valves than specimens of A. conradi 

or A. empirensis.

The largest individual of A. taliaferroi from the 

Topsy Formation is 15.8 mm high and 17.3 mm long-, 

and the smallest is 12.0 mm high and 12.1 mm long". 

Specimens from the lower part of the Yakataga Formation throughout the Gulf of Alaska region are of 

similar size. Wherever they occur, however, most 

individuals are somewhat distorted from burial compaction and tectonic forces.

The precise stratigraphic range of A. taliaferroi 

has not been established. It has been reported previously only from about the upper 213 m of the Poul 

Creek Formation (Clark, 1932; Addicott and others, 

1971) and from the lower part of the Yakataga 

Formation (Kanno, 1971) in the Yakataga district. 

These occurrences span a stratigraphic interval approximately equal to the Pillarian and Newportian 

Stages (early Miocene through early middle Miocene) of the Pacific Northwest.

Lucinoma acutilineata (Conrad, 1849)

Figures 15-16

The combination of nearly circular outline, regularly spaced and .sharply raised concentric lamellae, 

and concentric interspaces with numerous fine 

threads distinguishes this species. As noted by Addicott (1976a), L. acutilineata is usually preserved 

with articulated valves, as it is in the Topsy Formation. All Topsy specimens are distorted.

The specimens at hand are the first ones reported 

from Alaska, although this species is found commonly in middle Tertiary strata in Washington, 

Oregon, and California. The earliest occurrence of 

L. acutilineata is in the Eugene Formation of westcentral Oregon (Hickman, 1969), strata which have 

been assigned to the late Eocene to early Oligocene 

part of the Galvinian Stage by Armentrout (1975). 

Its highest startigraphic appearance is in the Astoria 

Formation in northwestern Oregon (Moore, 1963), 

which is included in the Newportian Stage (Addicott, 

1976b). The presence of L. acutilineata in the Topsy 

fauna provides a significant tie with the better 

known Tertiary faunas of Washington and Oregon 

and is evidence that the Topsy is no younger than 

early middle Miocene.

The modern homologue of this species is Lucinoma 

annulata (Reeve, 1850), which lives in depths of 20 

to 800 m between Alaska and Baja California, Mexico, but is found most abundantly in the inner sublittoral zone (0-100 m) (Burch, 1944). Compared to 

L. acutilineata, L. annulata, has a shorter posterior 

dorsal margin (Stewart in Tegland, 1933) and a

heavier hinge (Moore, 1963). As also pointed out by 

Moore (1963), the anterior tooth on the right valve 

of L. acutilineata is short and blunt, rather than 

thin and bladelike on L. annulata, and the cardinal 

tooth seems to be shorter on L. annulata. In addition, 

the left anterior tooth of L. acutilineata is heavier 

and not so deeply incised as on L. annulata (Moore, 

1963).

Macoma albaria (Conrad, 1849)

Figures 4-6

This species is characterized by its relatively 

small size, by the proximity of its beaks to the posterior end, and by its posteriorly flexed valves.

Macoma albaria has not been recognized previously from Alaska. Its presence in the Topsy provides a new tie between Tertiary strata of the Gulf 

of Alaska and the Pacific Northwest. This bivalve 

is well known in Miocene deposits in Oregon and 

Washington, where it has been reported in the Pillarian Nye Mudstone and Newportion Astoria Formation in western Oregon (Moore, 1963) and in the 

Pillarian Clallam Formation in northwestern Washington (Addicott, 1976a). As noted by Addicott 

(1976a), M. albaria is similar to M. twinensis 

Clark, 1925. The latter species is known from upper 

Oligocene rocks in northwestern Washington and is 

doubtfully reported from the lower Miocene Clallam 

Formation (Addicott, 1976a) in the same area. The 

importance of M. albaria in the Topsy rests on its 

last known occurrence in middle Miocene strata of 

Oregon. Even if its stratigraphic range were extended to encompass the upper Oligocene records 

now assigned to M. twinensis, its value in dating the 

Topsy Formation would not be diminished.

Macoma aff. M. albaria (Conrad, 1849) 

Figures 13-14

This species is represented by a single left valve 

that is well preserved and nearly complete but shows 

only exterior features. Its shape is most similar to 

that of M. albaria (Conrad, 1849), which occurs in 

lower and middle Miocene strata of Oregon and 

Washington (Moore, 1963; Addicott, 1976a). However, the Topsy specimen is distinctly more inflated 

than M. albaria, has a straighter ventral margin, a 

more prominent umbo, and blunter posterior termination. This valve is also similar to M. twinensis 

Clark, 1925, which is found in faunas of late Oligocene and possibly early Miocene age in Oregon and 

Washington (Addicott, 1976a), but differs from the 

latter species by its more prominent umbo, smaller 

relative height, and more inflated left valve. An-
MIOCENE MOLLUSKS OP THE TOPSY FORMATION, LITUYA DISTRICT, ALASKA C9

other similar species is M. brota Dall, 1916, which 

lives from Arctic Canada to Puget Sound, Wash., 

and is reported in Pleistocene faunas in Arctic 

Canada and British Columbia (Coan, 1971). The 

Topsy Macoma, however, is distinguished from M. 

brota by having a less elevated anterior dorsal margin, a more narrowly rounded anterior end and 

straighter ventral margin, and a distinctly moire inflated left valve. Future studies may reveal an ancestral relation between M. brota and the Miocene 

Macomas mentioned here.

Macoma incongrua (von Martens, 1865) 

Figure 10

This relatively small Macoma is characterized by 

its inflated valves, broadly and evenly rounded anterior end, and acutely angled posterior end. The 

posterior dorsal and ventral margins are straight 

and steeply sloping, and there is a distinct flexure 

to the right and a slight gape at the posterior end.

This species is the most frequently encountered 

Macoma in Gulf of Alaska Tertiary strata. It is well 

represented in beds of the lower part of the Yakataga Formation in the Yakataga and Lituya districts (of presumed early to late Miocene age) and 

has been reported in the upper part of the Poul 

Creek Formation at Cape Yakataga (Kanno, 1971) 

in beds of presumed early Miocene age. Its occurrence in the Pliocene and Pleistocene portions of 

the Yakataga Formation has been reported but not 

well documented, and it has been questionably reported in strata as old as late Oligocene (Kanno, 

1971).

As noted by Coan (1971) and Kanno (1971), 

Holocene specimens from the northeastern Pacific 

referred to M. incongrua differ in interior shell features from Holocene specimens of Japan (from 

which the holotype comes). Northeastern Pacific 

Pleistocene and Holocene specimens referred to M. 

incongrua by earlier workers have been placed in 

Macoma (Macoma) obliqua (Sowerby, 1917) by 

Coan (1971), a species also recognized in the Red 

Crag (lower Pleistocene) of England. Because interior shell features are not observable in most Alaskan 

Tertiary specimens referred to M. incongrua, and 

differences between M. incongrua and M. obligue 

are not always expressed in exterior morphology, the 

identity of specimens from the upper part of the 

Poul Creek and lower part of the Yakataga Formations is uncertain. It is most probable that these 

Miocene specimens belong to M. incongrua rather 

than M. obliqua, but proof of this will depend on collecting more Alaskan specimens in which interior 

features can be observed.

Individuals from the Topsy Formation figured 

here are of average size for Gulf of Alaska Tertiary 

specimens.

Macoma aff. M. twinensis Clark, 1925 

Figures 7-9

Specimens from the Topsy Formation are juveniles and young adults, resembling the holotype of 

M. twinensis Clark, 1925, which is also a juvenile 

specimen. Juveniles of M. twinensis differ from 

adults by having a more acutely rounded posterior 

end and less distinct umbones.

Macoma twinensis is reported in faunas of late 

Eocene through early Miocene age in the Pacific 

Northwest, its highest stratigraphic occurrence being doubtfully identified specimens from the lower 

Miocene Clallam Formation (Addicott, 1976a). The 

largest Topsy specimens are much more inflated 

than young adults of M. twinensis from the Pacific 

Northwest, so their species assignment will be uncertain until adult Topsy specimens are collected.

Mya sp.

This genus is represented in the Topsy Formation by a single right valve with its posterior end 

missing. The specimen is 52 mm high, with its umbo 

and ventral margin nearly intact.

The Topsy specimen most probably is Mya (Mya) 

cuneiformis (Boehm, 1915), which commonly occurs 

in Yakataga Formation faunas of presumed middle 

Miocene age in the Lituya district and is especially 

abundant in the Cenotaph Island section. MacNeil 

(1965) cited records of M. cuneiformis from presumed middle Miocene strata in the Cape Yakataga 

area and on Kodiak Island, Alaska, and from presumed middle Miocene to lower Pliocene beds in 

Japan and Sakhalin. Mya (Mya) truncata Linnaeus, 

1758, is also common in middle Miocene to Holocene 

faunas of southern Alaska (MacNeil, 1965), though 

it is not so common as M. cuneiformis in the Yakataga Formation of the Lituya district.

In the modern northeastern Pacific, Mya species 

occupy a bathymetric range from the intertidal zone 

to 50 m (Keen and Coan, 1974), burrowing into 

sandy mud.

Nuculana (Saccella) sp. 

Figure 12

Saccella is characterized by having a pointed posterior rostrum, sculpture of strong concentric rugae, 

posterior and anterior series of teeth equal, and a
CIO SHORTER CONTRIBUTIONS TO PALEONTOLOGY, 1979

U-shaped pallial sinus. The Topsy specimens are 

molds and casts that preserve only small portions of 

exterior sculpture and hinge lines and that lack impressions of pallial lines. The visible features of 

these specimens, however, suggest placement in 

Saccella. This subgenus is represented by many 

North Pacific Tertiary species, although it has not 

yet been recognized in the Yakataga Formation.

Periploma (Aelga) besshoensc (Yokoyama, 1924) 

Figure 3

When typically developed, the shell of this species 

is nearly equidimensional, with its posterior extremity distinctly compressed and slightly produced; 

the anterior margin is broadly rounded. The most 

common variation is for the posterior end to be 

greatly produced and broadly rounded, whereas the 

anterior end is reduced and often slightly truncated 

(Kanno, 1971).

This species was described from Japan, where it 

occurs in Oligocene and Miocene strata. Kanno 

(1971) recognized it in the upper part of the Poul 

Creek Formation and the lower part of the Yakataga 

Formation of the Yakataga district. He further 

noted that the posteriorly elongate variety seemed 

to occur only in the lower part of the Yakataga Formation, whereas the typical variety was found only 

in the upper part of the Poul Creek Formation. The 

Topsy Formation specimen is of the elongate variety 

known in the lower part of the Yakataga Formation, 

which provides a possible link between these two 

stratigraphic intervals. As emphasized by Kanno 

(1971), the seeming division of shell forms between 

the Yakataga and Poul Creek Formations requires 

confirmation.

Periploma lives in the modern northeastern Pacific 

in depths of 20 to 90 m (Burch, 1944; Keen and 

Coan 1974) ranging from Alaska to Peru.

Spisula addicotti Kanno, 1971

Figure 11

The shell of this species is elongate anteriorly, 

with prominent umbones situated posteriorly, and 

broadly rounded anterior and posterior extremities 

(especially in younger individuals).

This species has been reported only from the Poul 

Creek Formation (upper Eocene to lower Miocene; 

Allison, 1976) in the Yakataga district (Clark, 1932; 

Kanno, 1971; Addicott and others, 1971). Thus, its 

presence in the Topsy Formation is its highest 

known stratigraphic occurrence. The Topsy specimen is a juvenile showing the broadly rounded extremities that seem to characterize this species, 

especially in younger individuals.

Spisula addicotti may be a junior synonym of S. 

trapezoides (Clark, 1932), which is known from the 

upper part of the Poul Creek Formation (lower 

Miocene; Allison, 1976) in the Yakataga district 

(Clark, 1932; Addicott and others, 1971) and from 

Wishkahan faunas of the upper part of the Bear 

Lake Formation (upper middle Miocene to upper 

Miocene) on the Alaska Peninsula (R. C. Allison, 

oral commun., 1977). Compared to illustrations of 

the holotype of S. trapezoides, (Clark 1932; Addicott and others, 1971), S. addicotti appears to have 

a distinctly more elongate posterior end and a more 

evenly rounded posterior termination. However, the 

Topsy specimen of S. addicotti and the holotype of 

S. trapezoides are juveniles, making comparisons 

difficult.

Modern northeastern Pacific Spisula species inhabit depths from the intertidal zone to 100 m in 

sand substrates of exposed beaches and bays (Keen 

and Coan, 1974).

Thyasira cf. T. disjuncta (Gabb, 1866)

Figure 17

This lucinacean bivalve is characterized by its 

trigonal shape, broadly arched posterior dorsal margin, nearly straight anterior dorsal margin, strong 

sulcus that extends along the posterior dorsal slope 

from the umbo to the anterior ventral margin, and 

edentulous hinge.

Although some molluscan specialists have considered T. disjuncta to be synonymous with T. 

bisecta (Conrad, 1849), Bernard (1972) has exhaustively documented the anatomical differences 

and pointed out the distinctive shell morphology of 

each. I follow Bernard (1972) in considering Conchocele Gabb, 1866, into which T. disjuncta has often 

been placed, a junior synonym of Thyasira. The 

straight rather than concave anterior dorsal margin 

and less prominent umbo of T. disjuncta that distinguish it from T. bisecta are missing from the 

Topsy specimen. T. bisecta has never been reliably 

reported in Alaska Tertiary faunas, and illustrated 

Thyasira specimens from the Poul Creek Formation 

(Clark, 1932; Kanno, 1971; Addicott and others, 

1971) are undoubtely T. disjuncta. It is highly probable that the Topsy specimen is also T. disjuncta, 

although confirmation of this will depend on finding 

additional specimens.

Thyasira disjuncta is known in the North Pacific 

from late Eocene or early Oligocene to Holocene and 

in the modern Caribbean fauna (Boss, 1967). Be-
MIOCENE MOLLUSKS OF THE TOPSY FORMATION, LITUYA DISTRICT, ALASKA Cll

cause of confusion by past workers between T. disjuncta and T. bisecta, it is difficult to determine from 

literature records the exact geographic range of the 

former species in the North Pacific. In Gulf of 

Alaska Tertiary strata, T. disjuncta is recorded from 

the lower part of the Poul Creek Formation (Kanno, 

1971) as well as from the upper part (Clark, 1932; 

Addicott and others, 1971) in the Yakataga district. 

Specimens from a large erratic boulder at Cape 

Yakataga were judged by Kanno (1971, p. 62) to 

have come from the Poul Creek Formation, though 

he considered it possible they could have come from 

the overlying Yakataga Formation. The only known 

record of this species from the Yakataga Formation 

in the Yakataga district is that of Kanno (1971, p. 

22) from the Chaix Hills in strata of probable late 

Miocene or Pliocene age. Because its stratigraphic 

occurrence represents such an extensive time interval, even though the species occurs widely, it is not 

useful for correlation or age determination.

Besides T. disjuncta, the only other Tertiary 

Thyasira known in Alaska is T. alaskana Kauffman, 

1969. This species occurs on the Arctic coastal plain 

of northeastern Alaska, in the upper Miocene (?) 

and Pliocene Nuwok Member of the Sagavanirktok 

Formation, and is of Atlantic affinities.

Calliostoma sp. 

Figure 22-23

This genus has not been reported previously as a 

fossil in Alaska, although species of Calliostoma do 

live today as far north as southeastern Alaska. The 

species from the Topsy Formation is most similar 

to Calliostoma cammani Call, 1909, from the middle 

to lower Pliocene Empire Formation in Oregon. 

However, sculptural features of the Topsy specimen 

exclude it from C. cammani. It might belong to one 

of the Tertiary species described from Japan, the 

oldest of which is said to be Oligocene in age (Hatai 

and Nisiyama, 1952), or from the eastern Soviet 

Union. At present, no comparative specimens of 

Japanese or Soviet Calliostoma species are available, 

and literature citations are not sufficient to evaluate 

them, so comparisons with the Topsy specimen must 

be deferred.

?Colus sp. 

Figure 24

The elongate fusiform shell and relatively small 

aperture of the Topsy specimen suggest placement 

in Coins or an allied genus. This specimen is too 

worn and incomplete for certain generic placement, 

but parts of the exterior surface appear to be intact and smooth, further suggesting Coins as the 

most likely genus. Coins specimens are in the Poul 

Creek and Yakataga Formations, but are often too 

worn for specific identification, considering that differences among many Coins species are subtle.

Natica (Cryptonatica) clausa 

Broderip and Sowerby, 1829

Figure 25

A smooth, nearly globular shell with a semicircular callus concealing the umbilicus characterizes 

this species. It is distinguished from N. (C) oregonensis (Conrad, 1865) by its less elongate body 

whorl and lower spire. In general, fossil specimens 

of N. clausa also have distinctly thicker shells than 

N. oregonensis; modern individuals of N. clausa 

tend to have somewhat thinner shells than fossil 

specimens.

Natica clausa occurs commonly in cool- and coldwater Miocene to Holocene faunas of the North Pacific and is the only naticid found routinely in Alaskan 

Neogene and Pleistocene strata. Its reported first 

occurrence in the Gulf of Alaska Tertiary Province 

is in the upper part of the Poul Creek Formation 

(lower Miocene) of the Yakataga district (Marincovich, 1977), from strata of presumed late Juanian 

or Pillarian age. A coeval or possibly older occurrence is now known in the Juanian fauna of the socalled Narrow Cape Formation on Sitkinak Island 

in the western Gulf of Alaska (R. C. Allison, oral 

commun., 1977).

The single specimen of N. clausa from the Topsy 

Formation is 10.4 mm in height and 10.0 mm in 

diameter, which is average for Miocene specimens 

and much smaller than Pliocene to Holocene individuals. All fossil and modern occurrences of N. 

clausa are in faunas of decidedly cool- or cold-water 

aspect or in faunas with a well-developed cold-water 

element (Marincovich, 1977), so the presence of this 

species in the Topsy is strong evidence for a cooltemperate or slightly colder marine hydroclimate.

Natica (Cryptonatica) oregonensis (Conrad, 1865) 

Figure 26

This species is characterized by its smooth whorls 

and its semicircular callus concealing the umbilicus 

and by its elevated spire and elongate body whorl. 

These last two characters distinguish N. oregonensis 

from the related N. clausa Broderip and Sowerby, 

which also occurs in the Topsy Formation.

This is the first certain report of N. oregonensis 

north of Washington and Oregon, although it has 

been questionably identified in the Newportian fauna
C12 SHORTER CONTRIBUTIONS TO PALEONTOLOGY, 1979

of the Narrow Cape Formation on Kodiak Island in 

the western Gulf of Alaska (R. C. Allison, oral 

commun., 1977). It was previously known from the 

Astoria Formation of western Washington and western Oregon (Newportian Stage) and from the Empire Formation at Coos Bay, Oregon (Wishkahan 

and Graysian(?) Stages as used by Allison, 1976) 

(Marincovich, 1977). It is now also known in the 

Nye Mudstone (Pillarian Stage) of northwestern 

Oregon, on the basis of reassignment to the Nye 

Mudstone of localities formerly attributed to the 

Astoria Formation in northwestern Oregon (W. O. 

Addicott, oral commun., 1977). These verified occurrences range in age from early Miocene to early 

late Miocene.

?Neptunea (Neptnnea) plafkeri Kanno, 1971

Figure 27

This species is discriminated from other Tertiary 

Neptuneas and similar large gastropods in the Gulf 

of Alaska region by its high spire, acute apical 

angle, long anterioT canal, and nearly smooth shell 

sculptured only with fine incremental growth lines 

and a few radial varices of low relief near the aperture (Kanno, 1971; Nelson, 1974).

The poor condition of the Topsy specimen, missing 

all but an incomplete and worn body whorl, makes 

identity uncertain. This specimen is not deeply sculptured as are many Neptuneas, and the best preserved 

parts of the exterior surface show only fine incremental growth lines.

Neptunea plafkeri was described from specimens 

collected in the lower part of the Yakataga Formation at Cape Yakataga (Kanno, 1971), and it has 

also been collected in the upper part of the Poul 

Creek Formation there (C. A. Ariey, 1978a). This 

species is also reported from several Miocene localities of the Yakataga Formation in the Yakataga 

district and in beds now assigned to the Topsy Formation at Icy Point in the Lituya district (Nelson, 

1974). The sum of its known stratigraphic occurrences suggests a range of about early Miocene to 

middle or possibly late Miocene for N. plafkeri.

Neptunea (Sulcosipho) cf. N. (S.) tabulata (W. Baird, 1863) 

Figures 28-30

When seen as well-preserved fossil or modern 

specimens, N. tabulata is easily recognized by its 

elongate shape, strongly tabulate shoulder bounded 

by a thickened and minutely scaly spiral cord, and 

by its fine spiral ribs covering the whole outer surface. The Topsy specimen is a distorted and incomplete body whorl lacking earlier whorls or an anterior canal. The tabulate shoulder and fine spiral 

sculpture show up well and suggest placement of the 

specimen in N. tabulata. Even though there appear 

to be three sizes of spiral ribs on both N. tabulata 

and the Topsy specimen, however, the ribs of true N. 

tabulata are more boldly sculptured, seem to occur 

in a more regular sequence, and appear to be separated by wider interspaces than the ribs of the 

Topsy individual.

The specimens figured by Kanno (1971) as Neptunea (Sulcosipho) cf.N. (S.) tabulata appear to be 

the same as the Topsy shell. A specimen cited by 

Clark (1932) and refigured by Addicott and others 

(1971) as Neptunea aff. N. tabulata also probably is 

the same species. Kanno's (1971) specimens were 

collected from the lower part of the Yakataga Formation at Cape Yakataga, and dark's (1932) specimens from the same area also probably came from 

the lower part of the Yakataga Formation (Addicott and others, 1971). Nelson (1974) reported this 

species in middle Miocene to lower Pliocene beds of 

the Yakataga Formation throughout the Gulf of 

Alaska Tertiary Province. Recent collecting at Cape 

Yakataga has produced this species from the upper 

part of the Poul Creek Formation (C. A. Ariey, 

1978a). Thus, the known occurrences of this species 

indicate an approximate age range of early Miocene 

to early Pliocene.

Fusitriton oregonensis (Redfield, 1846) 

Figures 20-21

The characteristic features of this high-spired 

snail are its coarse axial ribs and fine, flattened 

spiral costae that are usually bifurcated. Most spiral 

interspaces on the Topsy specimen contain one 

slender thread, although such threads may be absent 

or as numerous as three per interspace (Smith, 

1970).

This species is well known in North Pacific Miocene and younger faunas, being most abundant in 

Pliocene and younger strata from Japan and Alaska 

south to California (Smith, 1970). Until recently, 

no precise data were known on the earliest occurrence of F. oregonensis. Smith (1970) reported 

specimens of "Fusitriton sp. ? aff. F. oregonensis" 

from Cape Yakataga Miocene strata of either the 

Poul Creek or Yakataga Formations. Recent collecting by C. A. Ariey (oral commun., 1977), however, showed F. oregonensis missing from the upper 

part of the Poul Creek Formation at Cape Yakataga 

but present in the stratigraphically highest Newportian fauna and in the Wishkahan fauna of the 

lower part of the Yakataga Formation there. Thus,
MIOCENE MOLLUSKS OF THE TOPSY FORMATION, LITUYA DISTRICT, ALASKA CIS

the oldest verified occurrence of this species is in the 

early middle Miocene portion of the Newportian 

Stage, thereby making F. oregonensis the species 

most important for inferring a maximum age for 

the Topsy fauna.

Modern occurrences are in temperate to cold 

waters of the North Pacific rim from Japan to 

southern California. Although F. oregonensis is 

known from depths as great as 2,370 m, it has been 

observed in the intertidal zone from Puget Sound, 

Washington, to southeastern Alaska, and in depths 

as shallow as 18 m in the southern Bering Sea and 9 

m in the Gulf of Alaska (Smith, 1970). Southwest 

from the Bering Sea and south of Puget Sound, it 

lives in progressively greater depths. It has been 

collected in temperatures of 7-11° C in Puget Sound 

and in waters less than 8°C off of southern California (Valentine and Emerson, 1961).

FOSSIL LOCALITY DESCRIPTIONS

The following locality numbers for the Topsy 

Formation are assigned by the Menlo Park, Calif., 

center of the U.S. Geological Survey. Fossil collections are housed in the Branch of Paleontology and 

Stratigraphy, Menlo Park, Calif., except for illustrated specimens, which are kept in the National 

Museum of Natural History, Washington, D.C.:

M6525 (Plafker field locality 75APr45A).—Isolated 

outcrop in intertidal zone of rock and sand 

beach about 3.3 km northeast of Icy Point; 669 

m south and 274 m west of NW. cor. sec. 15, T. 

40 S., R. 50 E., Mt. Fairweather (B-4) quadrangle, Lituya district, southeastern Alaska. 

Collected by George Plafker and Travis Hudson, 

June 1975.

M6526 (Plafker field locality 75APr40A).—Isolated 

outcrop along southern margin of Finger Glacier, 182 m south and 486 m west of NE. cor. 

sec. 33, T. 39 S., R. 50 E., Mt. Fairweather 

(B-4) quadrangle, Lituya district, southeastern 

Alaska. Collected by George Plafker and Travis 

Hudson, June 1975.

M6527 (Plafker field locality 75APr43D).—Isolated 

outcrop in intertidal zone of rock and sand 

beach, about 5.8 km north of Icy Point; 730 m 

south and 30 m east of NW. cor. sec. 10, T. 40 

S., R. 40 E., Mt. Fairweather (B-4) quadrangle, Lituya district, southeastern Alaska. 

Collected by George Plafker and Travis Hudson, 

June 1975.

M6528 (Marincovich field locality 75AM65).—Isolated outcrop near head of Fall Creek, along

strike from lower part of type-section of Topsy 

Formation, 289 m south and 274 m west of NE. 

cor. sec. 33, T. 37 S., R. 48 E., Mt. Fairweather 

(C-5) quadrangle, Lituya district, southeastern 

Alaska. Collected by Louie Marincovich, George 

Plafker, and Travis Hudson, June 1975.

REFERENCES CITED

Addicott, W. 0., 1976a, Molluscan paleontology of the lower 

Miocene Clallam Formation, northwestern Washington: 

U.S. Geological Survey Professional Paper 976, 44 p., 

9 pis., 10 figs.

————1976b, Neogene molluscan stages of Oregon and Washington, in Wornardt, W. W., ed., Symposium on the Neogene of the Pacific Coast: Society of Economic Paleontologists and Mineralogists, Pacific Section, San Francisco, Calif., April 1976, p. 95-115, 5 pis., 6 figs.

Addicott, W. 0., Kanno, Saburo, Sakamoto, Kenji, and Miller, 

D. J., 1971, Clark's Tertiary molluscan types from the 

Yakataga district, Gulf of Alaska, in U.S. Geological 

Survey Research 1971: U.S. Geological Survey Professional Paper 750-C, p. C18-C33, 6 figs.

Allison, R. C., 1976, Late Oligocene through Pleistocene molluscan faunas in the Gulf of Alaska region: International Congress on Pacific Neogene Stratigraphy, First, 

Tokyo, 1976, Abstracts of Papers, p. 10-13. Reprinted in 

Saito, Tsunemasa, and Ujiie, Hiroshi, eds., 1977, International Congress on Pacific Neogene Stratigraphy, 

First, Tokyo, 1976, Proceedings, p. 313-316.

Ariey, Catherine A, 1978a, Molluscan biostratigraphy of the 

upper Poul Creek and lower Yakataga Formations, Yakataga district, Gulf of Alaska: University of Alaska, M.S. 

thesis, Fairbanks, 249 p., 6 pis., 13 figs.

————1978b, Molluscan biostratigraphy of the upper Poul 

Creek and lower Yakataga Formations, Yakataga district, Gulf of Alaska: Stanford University Publications 

Geological Sciences, vol. 14, p. 1-2.

Armentrout, J. M., 1975, Molluscan biostratigraphy of the 

Lincoln Creek Formation, southwest Washington, in 

Weaver, D. W., and others, eds., Paleogene symposium 

and selected technical papers: American Association of 

Petroleum Geologists, Society of Economic Paleontologists and Mineralogists, Society of Economic Geophysicists, Pacific Sessions, 1975 annual meeting, Long 

Beach, Calif., p. 14-48, 7 figs.

Berggren, W. A., and Van Couvering, John, 1974, The late 

Neogene: Palaeogeography, Palaeoecology, Palaeoclimatology, v. 16, nos. 1-2, p. 1-216.

Bernard, F. R., 1972, The genus Thyasira in western Canada 

(Bivalvia: Lucinacea) : Malacologia, v. 11, no. 2, p. 

365-389, 17 figs.

Boss, K. J., 1967, Thyasira disjuncta (Gabb, 1866) in the 

Caribbean Sea: Bulletin of Marine Science, v. 17, no. 

2, p. 386-388.

Burch, J. Q., ed., 1944-46, Distributional list of the West 

American marine mollusks from San Diego, California, 

to the Polar Sea: Conchological Club South California, 

3 v. pagination various.

Clark, B. L., 1932, Fauna of the Poul and Yakataga Formations (upper Oligocene) of southern Alaska: Geological
C14 SHORTER CONTRIBUTIONS TO PALEONTOLOGY, 1979

Society of America Bulletin, v. 43, p. 797-846, pis. 

14-21, 1 fig.

Coan, E. V., 1971, The northwest American Tellinidae: 

Velinger, v. 14, suppl., 63 p., 12 pis., 30 figs.

Hatai, Kotora, and Nisiyama, Syozo, 1952, Check list of 

Japanese Tertiary marine Mollusca: Tohoku University 

Science Reports, ser. 2 (Geology), Special v. 3, 464 p.

Hickman, C. J. S., 1969, The Oligocene marine molluscan 

fauna of the Eugene Formation in Oregon: Oregon 

University Museum of Natural History Bulletin 16, 

112 p. 14 pis. 4 figs.

Kanno, Saburo, 1971, Tertiary molluscan fauna from the 

Yakataga district and adjacent areas of southern 

Alaska: Palaeontological Society of Japan, Special Paper 

16, 154 p., 18 pis., 20 figs.

Kauffman, E. G., 1969, Systematics and evolutionary position of a new Tertiary Thyasira (Bivalvia) from 

Alaska: Journal of Paleontology v. 43, no. 5, pt. 1, p. 

1099-1110, pi. 127, 5 figs.

Keen, A. M., and Coan, Eugene, 1974, Marine molluscan 

genera of western North America—an illustrated key: 

Stanford, Calif., Stanford University Press, 208 p.

LaViolette, P. E., and Seim, S. A., 1969, Monthly charts of 

mean minimum and maximum sea-surface temperatures 

of the North Pacific Ocean: U.S. Naval Oceanographic 

Office Special Publication 123, 54 p.

McLean, J. H., 1969, Marine shells of southern California: 

Los Angeles County Museum of Natural History, science 

series, 24, zoology no. 11, 104 p., 54 figs.

MacNeil, F. S., 1965, Evolution and distribution of the 

genus Mya, and Tertiary migrations of Mollusca: U.S. 

Geological Survey Professional Paper 483-G, p. G1-G51, 

11 pis., 3 figs.

MacNeil, F. S., Wolfe, J. A., Miller, D. J., and Hopkins, D. 

M., 1961, Correlation of Tertiary formations of Alaska: 

American Association of Petroleum Geologists Bulletin, 

v. 45, no. 11, p. 1801-1809.

[Marincovich, Louie, Jr.], 1976a, Fauna of Miocene age from 

the Topsy Formation, Alaska, in Geological Survey research 1976: U.S. Geological Survey Professional Paper 

1000, p. 195.

Marincovich Louie, Jr., 1976b, Miocene mollusks from the 

Topsy Formation, Lituya district, in Cobb, E. H., ed., 

The United States Geological Survey in Alaska—Accomplishments during 1975: U.S. Geological Survey 

Circular 733, p. 58.

————1977, Cenozoic Naticidae (Mollusca: Gastropoda) of 

the northeastern Pacific: Bulletins of American Paleontology, v. 70, no. 294, p. 169-494, pis. 17-42, 13 figs.

Miller, D. J., 1953, Preliminary geologic map and correlated 

columnar sections of Tertiary rocks in the southwestern 

part of the Lituya district, Alaska: U.S. Geological Survey Open-File Report, 53-193, 2 map sheets.

————1961, Geology of the Lituya district, Gulf of Alaska 

Tertiary Province, Alaska: U.S. Geological Survey openfile map.

Moore, E. J., 1963, Miocene marine mollusks from the Astoria 

Formation in Oregon: U.S. Geological Survey Professional Paper 419, 109 p., 32 pis., 9 figs.

Nelson, C. M., Jr., 1974, Evolution of the Late Cenozoic 

gastropod Neptunea (Gastropoda: Buccinacea) : Berkeley, California University, Ph. D. thesis., 802 p., 66 pis. 

17 figs.

Plafker, George, 1967, Geologic map of the Gulf of Alaska 

Tertiary Province, Alaska: U.S. Geological Survey Miscellaneous Investigations, Map 1-484, scale 1:500,000.

————1971, Pacific margin Tertiary basin, in Future petroleum provinces of North America: American Association of Petroleum Geologists Memoir 15, p. 120-135.

Plafker, George, and Addicott, W. 0., 1976, Glaciomarine deposits of Miocene through Holocene age in the Yakataga 

Formation along the Gulf of Alaska margin, Alaska: 

U.S. Geological Survey Open-File Report 76-84, 36 p., 

6 figs.

Rau, W. W., Plafker, George, and Winkler, G. R., 1977, Preliminary foraminiferal biostratigraphy and correlation 

of selected stratigraphic sections and wells in the Gulf 

of Alaska Tertiary Province: U.S. Geological Survey 

Open-File Report 77-747, 54 p.

Schenck, H. G., 1936, Nuclid bivalves of the genus Acila: 

Geological Society of America Special Paper 4, 149 p. 

18 pis. 15 figs.

Smith, J. T., 1970, Taxonomy, distribution, and phylogeny of 

the cymatiid gastropods Argobuccinum, Fusitriton, Mediargo, and Priene: Bulletins of American Paleontology, v. 

56, no. 254, p. 445-573, pis. 39-49, 17 figs.

Tegland, N. M., 1933, The fauna of the type Blakeley upper 

Oligocene of Washington: California University, Department of Geological Sciences Bulletin, v. 23, no. 3, 

p. 81-174, pis. 2-15.

Valentine, J. W., and Emerson, W. K., 1961, Environmental 

interpretation of Pleistocene marine species—a discussion: Journal of Geology, v. 69, no. 5, p. 616-618.

Wagner, C. D., 1974, Fossil and Recent sand dollar echinoids 

of Alaska: Journal of Paleontology, v. 48, no. 1, p. 

105-123, 3 pis., 2 figs.
Variability in 

Trithyrodinium Drugg 1967

By FRED E. MAY and DON G. BENSON, JR.

SHORTER CONTRIBUTIONS TO PALEONTOLOGY, 1979

GEOLOGICAL SURVEY PROFESSIONAL PAPER 1125-D

The considerable amount of archeopyle variation 

observed in Trithyrodinium Drugg 1967 

cautions the use of archeopyle outline in 

peridinioid dmoflagellate cyst taxonomy

CONTENTS

Page

Abstract _____________________________________________ Al

Introduction ______________________________________ 1

Acknowledgments ___________________________________________ 1

Notes on paleobiogeography ________________________________________ 1

Systematic paleontology ______________________________________________ 4

References cited _________________________________________ 15

ILLUSTRATIONS

Page

FIGURE 1. Map showing distribution of Vernedia during the Cretaceous ______________________________ — ____ A2

2. Map showing distribution of Peruviella and Sogdianella during the Cretaceous ________________________ 3

3. Graph showing relationship of height and maximum diameter among specimens of Vernedia freisi Kollmann and Sohl ______________________________________________________ 6

4. Camera lucida drawings of axial sections of Sogdianella aff. S. peruviana (Olsson) (x 2.5), Vernedia 

freisi Kollmann and Sohl, n. sp. (x 1.3 and 1.5), Peruviella gerthi Olsson (x 1-3), Peruviella dolium (Roemer) (x 1.6), Peruviella dolium (Roemer) (x 1) _______--___-_-____---_-- 7

5. Photographs of Vernedia freisi Kollmann and Sohl and Peruviella gerthi Olsson _________________ 8

6. Photographs of Sogdianella subcylindrica Kollmann and Sohl, n. sp.; Sogdianella peruviana (Olsson) ; and

Peruviella dolium (Roemer) ___________________________________________________ 10

7. Graph showing relationship of height and maximum diameter in Peruviella gerthi Olsson and Peruviella

dolium (Roemer) _________________________________ — _^_______ — ____ 13

ill

SHORTER CONTRIBUTIONS TO PALEONTOLOGY, 1979

VARIABILITY IN TRITHYRODINIUM DRUGG 1967

By FRED E. MAY and DON G. BENSON,, JR. x

ABSTRACT

The shape, size, and number of sides of each opercular 

piece are highly variable in the two species of Trithyrodinium 

Drugg 1967 reported on in this paper. Populations of both 

Trithyrodinium striatum Benson 1976 and T. cf. T. fragile 

Davey 1969 from the northern New Jersey Coastal Plain 

have 31/31 archeopyles that display considerable variation in 

the opercular pieces on the endocyst. The variation results 

from the differing height in the 2a paraplate. Specimens 

with a reduced 2a that does not contact the apical series but 

is separated from the apical series by the anterior joining 

of the la and 3a have hexagonal la and 3a paraplates, a 

pentagonal 2a paraplate, and an 11-sided endoarcheopyle. 

Specimens with a "typical" 2a paraplate that makes contact with the apical series, separating the la and 3a paraplates, have pentagonal la and 3a paraplates, a hexagonal 

2a paraplate, and a 12-sided endoarcheopyle. The only exception to the last example is in specimens where the 2a, because of its increased height, just makes contact with the 

apical series. In such specimens the la, 2a, and 3a are all 

pentagonal in outline, and the archeopyle is 11 sided. The 

delicate nature of the pericyst makes it difficult to study, 

although it appears to be 31 for the types reported here.

INTRODUCTION

Fossil peridinioid dinoflagellate cysts having 

archeopyles formed of the la, 2a, and 3a paraplates 

have been assigned to the genus Trithyrodinium 

Drugg, 1967, Initially Drugg (1967) felt that the 

archeopyle of the type species T. evittii was 31/31 

(after Evitt's 1967 classification) ; however, he was 

not certain, and he felt that all the opercular pieces 

were removed as a unit. Subsequent observations by 

Evitt and Drugg (written commun., 1976) using interference contrast have shown the archeopyle to be 

31/31. Davey (1969) emended Drugg's (1967) 

generic description and suggested that the archeopyle formula is I/3I. Lentin and Williams (1976) 

emended the archeopyle formula to 31/31. Only one 

investigation thus far (Evitt, 1967) has reported

1 Amoco Production Co., New Orleans, La.

any morphologic variability in the opercular pieces 

of Trithyrodinium. The present study provides the 

first specific examples, however, of the gradation in 

variability in both the archeopyle and opercular 

pieces. Two species, T. striatum Benson, 1976, and 

T. cf. T. fragile Davey, 1969, observed from Maestrichtian sedimentary rocks of the Atlantic Coastal 

Plain of New Jersey and Maryland (fig. 1), possess 

the same type of variability referred to by Evitt 

(1967, p. 38-39). The purpose of this report is to 

illustrate this gradation in variability in archeopyle

_PE_NN_SYLVANIA 

MARYLAND

20 40 60 KILOMETERS

I I I

FIGURE 1.—Map of the northern Coastal Plain, showing collecting areas at Round Bay (R), Md., and Poricy Brook

„ . (P), N.J. Specimens were collected from Upper Cretaceous units, the Severn Formation at Round Bay, and the 

Navesink Formation and Red Bank Sand at Poricy Brook.

Dl
D2 SHORTER CONTRIBUTIONS TO PALEONTOLOGY, 1979

B

H

60

FIGURE 2.—Specimens of Trithyrodinium cf. T. fragile collected from Poricy Brook, N.J., showing gradation in the 

morphologic variability of anterior intercalary paraplates. (Also see fig. 3, sketches of endopercular pieces on the 

above specimens.) A-C, reduced 2a paraplates separated from the apical series by anterior joining of the la and 

3a paraplates. D, a 2a paraplate that just makes contact with the apical series. E-H, 2a paraplates that make contact with the apical series and are increasingly broadened along their anterior margins.

and opercular-piece morphology for two species of 

lone peridinioid genus.

OBSERVATIONS

Although Evitt (1967) reported the existence of 

variability in Trithyrodinium archeopyle and opercular-piece morphology, until now no particular 

species have been described or illustrated showing 

this gradation. We first observed the complete gradation in samples from the Navesink Formation at 

Poricy Brook, Monmouth County, N.J. Specimens 

from this locality demonstrating the gradation are
VARIABILITY in TRITHYRODINIUM DRUGG 1967 D3

60 m

FIGURE 3.—Sketches of endopercular pieces from specimens shown in figure 2, in same sequence. Position of 

la, 2a, and 3a paraplates are shown in figure 3A, C, and F. Note the increasing height of 2a paraplate, 

which does not contact apical series in A-C; 3D shows the 2a paraplate just making contact with the apical series; E-H shows 2a paraplates, which make contact with the apical series. The 11-sided archeopyle outline is shown in A ; the 12-sided archeopyle outline is shown in H. Hexagonal la and 3a paraplates and a pentagonal 2a paraplate are shown in B; pentagonal la and 3a paraplates and a hexagonal 

2a paraplate are shown in G. The clockwise numbering of endoarcheopyle and paraplate sides is not intended as a formal morphologic nomenclature but is used only for illustration.

shown in figure 2A-H, and sketches illustrating the 

gradation within the same specimens are shown in 

figure 3A-H. All specimens illustrated come from 

one sample (R1023K), c'ollected about 5 m above the 

base of the section at Poricy Brook (fig. 1).

In T. cf. T. fragile the morphologic gradation in 

the anterior intercalary series consists of variations 

in the height of the 2a paraplate, the number of 

sides per paraplate, and the relative positions of the 

anterior paraplate margins. At one extreme the 2a 

is reduced in height, the la and 3a paraplates join 

anterior of the 2a, and the la and 3a paraplates are 

hexagonal whereas the 2a is pentagonal (fig. 2A-C, 

fig. 3A-C). Where the 2a is increased in height, it

makes contact with the apical series, separating the 

la from the 3a, and causes all three anterior intercalary paraplates to become pentagonal (fig. 2D, fig. 

fig. 3D). At the other extreme, the 2a paraplate, in 

contact with the apical series, is broadened along its 

anterior margin, causing further separation of the 

la and 3a paraplates and thus forming a standard 

anterior intercalary series. In this series, all three 

paraplates make contact with the apical series, and 

the la and 3a paraplates are pentagonal whereas the 

2a is hexagonal (fig. 2E-H, fig. 3E-H). This paraplate configuration can be referred to as a standard 

configuration, whereas the other configuration, in 

which only the la and 3a paraplates make contact
D4 SHORTER CONTRIBUTIONS TO PALEONTOLOGY, 1979

with the apical series, can be referred to as a nonstandard configuration. These terms will be used in 

this report for the purpose of discussion. Close examination of the pericyst shows the periarcheopyle to 

be similar in size and outline to the endoarcheopyle, 

indicating a 31/31 archeopyle formula (as in Evitt, 

1967) ; however, the delicate nature and frequent 

absence of the pericyst make it difficult to study in 

the same detail as the endocyst.

A few specimens of T. cf. T. fragile have lost their 

anterior intercalary paraplates (the endopercular 

pieces). Although in such specimens the geometry 

of the adjacent endopercular paraplate boundaries 

cannot be seen, the existence of the extremes in 

gradation can still be determined by the number of 

sides and morphology of the endoarcheopyle. Where 

the 2a paraplate is reduced and does not make contact with the apical series (fig. 2A-C, Fig. 3A-C), 

the archeopyle is 11 sided, and the central anterior 

margin of the archeopyle is V shaped (fig. 4A). 

Where the 2a contacts the apical series and is broadened along its anterior margin, the archeopyle is 12 

sided, and the central anterior margin of the archeopyle forms a truncated V (fig. 45). Thus, this type 

of variability in Trithyrodinium endopercular pieces 

and endoarcheopyle outline can be detected whether 

the anterior intercalary paraplates are in position 

or not.

Another example of this type of endoarcheopyle 

and endopercular-piece variability is seen in 

T. striatum Benson, 1976. Specimens displaying this 

variability occur in the Upper Cretaceous Severn 

Formation (formerly Monmouth Formation) of 

Round Bay, Md. (fig. 1). Less variable specimens 

were recovered from the Navesink Formation and 

Red Bank Sand (both of the Monmouth Group) at 

Atlantic Highlands, N.J. (May, 1976, p. 240). As 

with T. cf. T. fragile, the complete gradation exists 

within single populations of T. striatum from the 

Severn Formation. Although specimens of T. striatum frequently have lost their endopercular 

pieces, the general variation in the endoarcheopyle 

outline supports the idea that they too vary the same 

way. Also, the same variation is seen in the few 

specimens that retain part or all of their opercular 

pieces (fig. 5A-Z)). Where the endopercular pieces 

are missing, the 11- and 12-sided endoarcheopyles 

are apparent.

In both T. cf. T. fragile and T. striatum the high 

degree of variability in endoarcheopyle and endopercular-piece morphology does not occur on all specimens observed, nor was it present on specimens from

"V" 

NOTCH

TRUNCATED 

"V" NOTCH

60 m

FIGURE 4.—Variation in endoarcheopyle outline for trithyrodinioid cysts discussed in this report. A, Specimens where 

reduced 2a paraplates do not make contact with the apical 

series have 11-sided endoarcheopyles with V notch along 

central anterior margin of endoarcheopyle. B, Specimens 

where 2a paraplates do make contact with apical series 

are somewhat broadened along anterior margin of the 2a 

paraplate have 12-sided endoarcheopyles with truncated 

V notch along central anterior margin of endoarcheopyle.

all collecting horizons. Similar-age specimens of T. 

cf. T. fragile observed in the U.S. Geological Survey 

Clubhouse Crossroads Core (depth 317 m; late Campanian) near Charleston, S.C., exhibited little variability in the anterior intercalary paraplates. All the 

nearly 50 specimens observed had 2a paraplates that 

made contact with the apical series. The specimens 

of T. striatum that we observed in the Navesink Formation and Red Bank Sand at Atlantic Highlands, 

N. J., als'o lacked the extreme variability, although 

Evitt (oral commun., 1976) reported that he has 

observed the complete gradation in specimens from 

that area. At Round Bay, Md., the complete gradation was observed in some samples but not in others.

TAXONOMIC CONSIDERATIONS

Although it might seem tempting to assign those 

trithyrodinioid variants with standard and those 

with nonstandard anterior intercalary paraplate configurations to different taxonomic groups, in the 

biological sense such assignments would be highly 

artificial. As illustrated and described herein, the 

standard and nonstandard configurations can be 

intergradational within some single populations. The 

fact that nonintergrading populations can be found 

does not change this. For this reason we suggest 

that the archeopyle formulas I/3I and 31/31 include 

whatever intergradable morphologic variation can 

be demonstrated in single populations. W. R. Evitt 

(written commun., 1976) expressed the feeling that 

the endoarcheopyle and endopercular-piece morphologic variation reported herein is within the 

intended use of the archeopyle formula 31/31. This
VARIABILITY in TRITHYRODINIUM DRUGG 1967 D5

D

FIGURE 5.—Photomicrographs and sketches of specimens of Trithyrodinium striatum Benson, 1976, showing variabiilty in 

the morphology of endopercular pieces and in the outline of endoarcheopyle. Sketches were made from the photomicrographs above them, so that A' corresponds to A, B' corresponds to B, and so on. Gradation in variability of endopercular pieces can be seen from left to right in both the photomicrographs and sketches. A, A', reduced 2a paraplate 

separated from apical series by anterior joining of la and 3a paraplates. B, B', 2a paraplate just making contact 

with apical series, separating la and 3a paraplates. C, C' nd D, D', 2a paraplate in contact with apical series has a 

broadened anterior margin, further separating la and 3a paraplates.

use would preclude any further formal emendation 

of the generic description of Trithyrodinium. However, such endoarcheopyle and endopercular-piece 

variability should be reported in the species 

description.

The selection of the term "nonstandard paraplate 

configuration" for the anterior intercalary series that 

includes the reduced 2a paraplate is intended herein 

only to simplify the discussion and not to introduce 

any formal taxonomic terminology. The term "nonstandard" suggests our feeling that the configuration that includes the reduced 2a paraplate is perhaps uncommon. It is difficult to evaluate how stratigraphically and geographically extensive the nonstandard configuration is in the fossil record. However, we point out that after finding one species exhibiting the variation, we had little difficulty in 

finding another.

Whether nonstandard, variable, or uncommon 

opercular paraplate configurations exist for other 

peridinioid taxa has not yet been reported. Peridinioid cysts that are typical broad-shouldered forms, 

such as Chatangiella granulifera (Manum) Lentin 

and Williams 1976 and Isabelidinium dakotaense 

(Stanley) Lentin and Williams 1977, have been illustrated with I/3I archeopyles (Manum, 1963, pi. 3, 

fig. 8; Stanley, 1965, pi. 19, figs. 1-3). However, the 

broad-shouldered peridinioid forms are typically I/I. 

Population studies of types such as these might further increase our understanding. The only solution 

to the problem of how variable peridinioid-cyst archeopyles and opercular pieces might be lies in pop-
D6 SHORTER CONTRIBUTIONS TO PALEONTOLOGY, 1979

ulation studies of taxa in single localities, in 

different geographic areas, and from different stratigraphic intervals. Exceptions to standard archeopyle 

and opereular-piece paraplate configurations may be 

rare, but before they are assumed to be rare, further 

detailed studies should be done. How common such 

variability is should be critically tested before archeopyle morphology is used as a main criterion in 

peridinioid cyst taxonomy. Evitt (written eommun., 

1976) stated that modern dinoflagellates are much 

more variable in paraplate outline and configuration 

than are the fossil cysts. This difference may only 

be app'arant, because population variation in the 

fossil cysts may not have been adequately studied 

and reported.

CONCLUSIONS

Trithyrodinium striatum Benson 1976 and T. cf. 

T. fragile Davey 1969 display a considerable range 

in endoareheopyle and endopercular-piece variation. 

The variation ranges from a nonstandard anterior 

intercalary series on the endocyst, in which the 

pentagonal 2a paraplate is reduced in height and the 

hexagonal la and 3a paraplates are allowed to join 

anterior to the 2a, separating it from the apical 

series, to a standard anterior intercalary series on 

the endocyst, in which the la and 3a paraplates are 

pentagonal in outline, the 2a is hexagonal, and all 

three intercalaries make contact with the apical 

series along their anterior margins. In specimens 

where the 2a paraplate just makes contact with the 

apical series, all three intercalaries are pentagonal. 

The archeopyle for a nonstandard anterior intercalary series is 11 sided; the archeopyle for a standard series is 12 sided.

The presence of the variability at some localities 

or horizons but not at others may be caused by 

ecophenotypic response to only particular environments. If a species existing at one time was composed of a group of populations separated geographically and existing in a variety of environments, 

ecophenotypic response may have affected the 

morphology of each population differently, and archeopyle variability within one species, for example, 

need not be expected to be the same everywhere at 

that time. Likewise, as environments change through 

time in one area, ecophenotypic response to those 

changes may cause degrees of variation not observed

at each level in the sedimentary record. Thus, within 

the fossil record in one geographic area, the appearance and disappearance of degrees or types of 

variation may simply reflect changing environments.

The archeopyle formula 31/31 should include 

whatever degree of intergradational variation that 

can be demonstrated within single populations. For 

example, we feel that the nonstandard anterior intercalary series on the endocysts reported herein for 

T. striatum and T. cf T. fragile fall within the 31/31 

archeopyle formula.

Archeopyle studies should be done on other peridinioid cyst populations, such as those of Chatangiella granulifera (Manum) Lentin and Williams 

1976 C. verrucosa (Manum) Lentin and Williams 

1976 and Isabelidinium dakotaense (Stanley) Lentin 

and Williams 1977, to see if the I/3I archeopyles of 

the different species are natural variants of the 

I/1 formula and if other kinds of variantions exist,

REFERENCES CITED

Benson, D. G., 1976, Dinoflagellate taxonomy and biostratigraphy at the Cretaceous-Tertiary boundary, Round 

Bay, Maryland: Tulane Studies in Geology and Paleontology, v. 12, p. 169-233, pi. 1-15.

Davey, R. J., 1969, Some Dinoflagellate cysts from the Upper 

Cretaceous of northern Natal, South Africa: Paleontologia Africana, v. 12, p. 1-23, pi. 104.

Drugg, W. S., 1967, Palynology of the Upper Moreno Formation (Late Cretaceous-Paleocene), Escarpado Canyon, 

California: Paleontographica, Abt. B, v. 120, p. 1-17, pi. 

1-9.

Evitt, W. R., 1967, Dinoflagellate studies, [part] II, The 

archeopyle: Stanford University Publications, Geological 

Sciences, v. 10, no. 3, 83 p.

Lentin, J. K., and Williams, G. L., 1976, A monograph of 

fossil peridinioid dinoflagellate cysts: Bedford Institute 

of Oceanography Report BI-R-75-16, p. 1-237, pi. 1-21.

———— 1977, Fossil Dinoflagellate genus Isabelidinium nom. 

nov.: Palynology, v. 1, p. 167-168.

Manum, Svein, 1963, Some new species of Deflandrea and 

their probable affinity with Peridinium: Norsk Polarinstitutt Arbok 1962, p. 55-67, 3 pis.

May, F. E., 1976, Dinoflagellate cysts of the Gymnodiniaceae, 

Peridiniaceae, and Gonyaulacaceae from the Upper Cretaceous Monmouth Group, Atlantic Highlands, New Jersey: Virginia Polytechnic Institute and State University, 

Ph.D. thesis, 363 p., 23 pis.

Stanley, E. A., 1965, Upper Cretaceous and Paleocene plant 

microfossils and Paleocene dinoflagellates and hystrichosphaerids from northwestern South Dakota: Bulletins 

of American Paleontology, v. 49, no. 222, p. 179-384, 

31 pis.