Foraminifera from the 

Pierre Shale (Upper 

Cretaceous) at Red Bird, 

Wyoming

GEOLOGICAL SURVEY PROFESSIONAL PAPER 393-C
Foraminifera from the 

Pierre Shale (Upper 

Cretaceous) at Red Bird, 

Wyoming

By JAMES F. MELLO

STRATIGRAPHY, PALEONTOLOGY, AND SEDIMENTATION OF 

A CLASSIC REFERENCE LOCALITY OF THE PIERRE SHALE

GEOLOGICAL SURVEY PROFESSIONAL PAPER 393-C

Sixty-one foraminiferal taxa are described from 

the complete section of the Pierre Shale at 

Red Bird, Wyo.

UNITED STATES GOVERNMENT PRINTING OFFICE, WASHINGTON : 1971
UNITED STATES DEPARTMENT OF THE INTERIOR 

ROGERS C. B. MORTON, Secretary

GEOLOGICAL SURVEY 

William T. Pecora, Director

Library of Congress catalog-card No. 70-610218

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

Washington, D.C. 20402 - Price $1 (paper cover)
CONTENTS

Abstract_ _ _______________________________________

Introduction.______________________________________

Acknowledgments__ _ __________________________

Environmental interpretations__-_-_-_----____-_-___

Interpretations based on regional geology._________

Interpretations based on Foramimfera__--_________

Interpretations based on macrofossils____________

Comparison of foraminiferal faunas between the stratigraphic units.____________________________________

Page 

Cl 

1 

1 

1 

1

4

5

Vertical distribution and biostratigraphy_____________

Problems in the study of Foraminifera of western interior 

United States.___________________________________

Stratigraphic positions of the samples.________________

Sample preparation.________________________________

Systematic paleontology.____________________________

References cited____________________________________

Index _____________________________________________

ILLUSTRATIONS

[Plates 1-7 follow Index]

PLATE 1. Alabamina, Ammobaculites, Ammobaculoides?, Anomalinoides, Astacolus, Bathysiphon, Bulimina, and ?Buliminella.

2. Caucasina, Cibicides, Dentalina, Dorothia, Eouvigerina, Fissurina, Globigerinelloides, and Glomospira.

3. Frondicularia, Gaudryina, Glomospirella, and Gyroidina.

4. Haplophragmoides, Lagenammina, and Pseudobolivina?.

5. Heterohelix, Lagena, Lenliculina, Marginulina, Oolina, Pseudoclavulina?, Reophax, Saccammina, and Saracenaria.

6. Neobulimina, Silicosigmoilina, Spiroplectammina, and Trochammina.

7. Nodosaria, Stilostomella, Textularia, Trochammina, Verneuilinoides, and incertae sedis.

FIGTJKE 1. Graphs showing changes in foraminiferal faunal size and gross composition, bathymetry based on macrof ossils, 

and strandline position during deposition of the Pierre Shale at Red Bird, Wyo ______________________

2. Chart showing ranges and relative abundances of foraminiferal species which have restricted local ranges, are 

typically represented by numerous specimens, and are morphologically distinctive.______________________

3. Chart showing ranges of foraminiferal species in the Pierre Shale at Red Bird, Wyo., and their composite ranges 

from elsewhere in the Cretaceous interior seaway.___________________________________________________

4. Outline drawings of Spiroplectammina sp. 1 and of a topotype of S. semicomplanata_ _ _ ________________________

Page 

C7

7

14

15

15

50

53

Page 

C2

11

12

44

TABLES

TABLE 1. Summary of foraminiferal ratios and faunal-sample relationships____--_-_--__-_---------_-

2. Sizes and comparisons of macrofossil collections.___-_____________-____-_--__-_---_-------

3. Ranges and relative abundances of foraminiferal species._____-___-_-__--_--__-----------_-

4. Percentage of samples in each stratigraphic unit in which each species of Foraminifera is found.

5. Stratigraphic positions of the samples..-------------------------------------------------

Page

C4

6

8

11

14

rn

STRATIGRAPHY, PALEONTOLOGY, AND SEDIMENTATION OF A CLASSIC REFERENCE LOCALITY

OF THE PIERRE SHALE

FORAMINIFERA FROM THE PIERRE SHALE (UPPER 

CRETACEOUS) AT RED BIRD, WYOMING

By JAMES F. MELLO

ABSTRACT

Foraminifera were recovered from 75 samples taken from 

the complete section of the Pierre Shale exposed at Red Bird, 

Wyo. Arenaceous Foraminifera are dominanit in most samples, 

both in number of species and number of specimens, but some 

samples contained calcareous benthonic and planfctonic specimens, and many samples yielded internal molds of presumably 

calcareous species. Patterns of distribution of identifiable foraminiferal taxa show no convincing relationship with regional 

depositional history, macrofossil occurrences, or Holocene distributional patterns. Most foraminiferal species are rare and 

occur sporadically, and most of the rest are long ranging, either 

locally or regionally. No biostratigraphic subdivisions are 

proposed.

Of the 61 identified taxa, 46 are assigned positively or provisionally to previously named species, one species is described 

as new, and 14 taxa 'bear informal species nomenclature. The 

species Haplophragmoides excavata Cushman and Waters is 

emended to include five morphologic subgroups.

INTRODUCTION

The discovery of a well-exposed complete section 

of the Pierre Shale at Red Bird, Niobrara County, 

Wyo., by U.S. Geological Survey geologists and its 

subsequent intensive investigation (Gill and Cobban, 

1966; Sohl, 1967) provided a theoretically ideal framework for the study of Foraminifera. Careful stratigraphic work was done, and fine zonation based on 

mollusks was established. This created an excellent 

opportunity for relating the Foraminifera from the 

Pierre Shale to widely recognized fossil zones and 

regionally important stratigraphic units.

Despite the promise of these initial conditions, the 

results of this study were less than expected. The 

Foraminifera are monotonous in general faunal character. Nearly all recovered faunas are arenaceous and 

not very diverse, and most species are long ranging. 

All three factors limit the usefulness of these Foraminifera for zonation and environmental interpretation. 

If the character of foraminiferal faunas at Red Bird 

reflects the faunal character predominating in the 

Pierre Shale of other areas, the data and conclusions 

presented here may be of wider use than presently 

expected.

ACKNOWLEDGMENTS

Considerable help received from William A. Cobban, 

James R. Gill, and Robert E. Burkholder, U.S. Geological Survey, is gratefully acknowledged. Elinor 

Stromberg, U.S. Geological Survey, made the drawings of Foraminifera. Thanks are also due Cobban and 

Norman F. Sohl, U.S. Geological Survey, and Dr. 

John H. Wall, Research Council of Alberta, who 

reviewed the manuscript.

ENVIRONMENTAL INTERPRETATIONS 

INTERPRETATIONS BASED ON REGIONAL GEOLOGY

In general lithologic character, the Pierre Shale at 

Red Bird "* * * consists of dark- to light-grayweathering noncalcareous clayey to silty shale that is 

entirely of marine origin" (Gill and Cobban, 1966, 

p. Al). During deposition at Red Bird, the nearest 

strandlines were to the west and northwest. According 

to Gill and Cobban (1966, p. AST), the strandline was 

about 185-205 miles west of Red Bird during Gammon 

time, 135-160 miles to the west during Mitten time, 

and probably no more than 60 miles away during 

deposition of the Red Bird Silty Member (see fig. 1). 

Immediately after deposition of the Red Bird Silty 

Member, the strandline moved about 110 miles west of 

Red Bird, during which time the lower third of the 

lower unnamed member was deposited. While the 

middle third of the lower unnamed member was being 

deposited at Red Bird, uplift and erosion took place 

to the west, accompanied by a probable regression of 

the strandline nearer to Red Bird. Renewed transgression shifted the strandline to a point 150 miles west 

of Red Bird during deposition of the upper third of 

the lower unnamed member, the Kara Bentonitic Member, and the basal part of the upper unnamed member. 

During deposition of the upper unnamed member, 

the strandline shifted eastward and southeastward 

and was as close as 60 miles north of Red Bird during 

deposition of the upper third of the unit. The strandline was probably never nearer than 40 miles from 

Red Bird, and it was usually 100 or more miles away.

Cl
C2 DESCRIPTIVE STUDY OF A CLASSIC REFERENCE LOCALITY OF THE PIERRE SHALE

MEMBER AND NUMBERED

.Gammon Ferruginous Member

Red Bird Silty Member

46 

36 37 38 39 41 43 45 47 48 49 50 51 52

R R MM RM RM 20 25 30 35

M R RM EM RM RM RM RS S M EM R RM R EM EM R RMRMR?

LS LS ML MS

SAMPLE NUMBER

<=> 

"" 50-

o _

-L-1 I U L I I

RED BIRD, 

WYO.

35 40 

SAMPLE

<2 150 

FIGURE 1. Changes in foraminiferal faunal size and gross composition, bathymetry based on
FORAMINIFERA AT RED BIRD, WYOMING C3

UNIT OF MEASURED SECTION

Kara Bentonitic Member

Lower unnamed shale member

62 65 70 76

64j 69/ 71 72 75 77 78

EXPLANATION

Interpreted depth range of num 

bered unit of measured section

Generalized bathymetric curve 

Dashed where inferred

Bathymetric changes, based on 

macrofossil lists given in Gill 

and Cobban (1966). Bathymetric interpretations are by Erie 

Kauffman, U.S. National Museum (written commun., 1968). 

See Gill and Cobban (1966) 

for numbered units

EXPLANATION

Total number of foraminiferal 

species

O 

Number of planktonic species

A

Number of 

calcareous benthonic species

Letter symbols beneath sample 

number indicate presence of: 

R, Radiolaria

M . molds of calcareous Foraminifera 

L , linguloid brachiopod fragments 

S, inferred seed or spore cases B

Changes in size and composition 

of the foraminiferal fauna. See 

table 5 for sample numbers

45 50 

RM M RM RM M RM R

AND FOSSILS

RM R R 

M ML ML

75 

M R? L

MS

Changes in approximate percentage of arenaceous Foraminifera 

in the foraminiferal fauna, determined by assuming median 

absolute values for the relative 

abundance catagories used in 

this study

45 

NUMBER

 Regression of strandline inferred, 

based on erosion west of Red Bird

RED BIRD, 

" WYO.

D

Changes in strandline position, 

-100 based on data from Gill and 

Cobban (1966)

macrofossils, and strandline position during deposition of the Pierre Shale at Red Bird, Wyo.
C4 DESCRIPTIVE STUDY OF A CLASSIC REFERENCE LOCALITY OF THE PIERRE SHALE

Knowledge of the distance of the site of deposition 

from the shoreline, although helpful, is not sufficient 

evidence for interpreting the depth of the sea. Gill 

and Cobban (1966, p. A3Y-A38) summarized other 

lines of reasoning, based for the most part on inorganic criteria, which suggest that the Mitten and 

younger members were deposited at depths less than 

200 feet and that the Gammon Ferruginous and 

Sharon Springs Members were deposited at depths 

greater than 200 feet.

INTERPRETATIONS BASED ON FORAMINIFERA

Observation of living Foraminifera in Holocene 

environments is exceedingly difficult because of their 

small size. Little is known about the degree of ecologic 

control exerted by food preferences, temperature, 

light, turbidity, pH, Eh, and other factors, and no 

work has been done on functional morphology. Owing 

to ignorance of the relationship of the organisms to 

these basic factors, information on environmental 

relationships has been almost exclusively descriptive 

rather than meaningfully interpretive.

Specifically, distribution of Foraminifera has been 

related to depth more than to any other parameter. 

Data have been accumulated relating species, genera, 

and various ratios between taxa and between gross 

shell structure or living habits to depth in general and 

to specific Holocene environments in particular. Use 

of such information on Holocene Foraminifera for 

the interpretation of Cretaceous paleoenvironments is 

limited almost exclusively to comparison of planktonicbenthonic and arenaceous-calcareous benthonic ratios, 

and to generalizations based on characteristics such as 

faunal diversity. Most fossiliferous samples examined 

from the Pierre Shale at Red Bird were dominated by

TABLE 1. Summary of foraminiferal ratios and faunal-sample 

relationships

H o,

Lithologlc unit

1

Ila

00C C* °3 S

3-2 o

ES 3 .a 5 a

£3 °g °^

So J5 Js-s

s

<D S

M-Ss

o.S S'c' " ^

05 O

$ ft ®;

t> to >^ ^ ^

Upper unnamed shale member. 15 6.3 6. 7 20.0 6.0 0.1

Lower unnamed shale member. 18 7.6 33.3 11.1 7.1 .4

Red Bird Silty Member........ 18 8.2 61.2 38.8 4.9 2.8

Mitten Black Shale Member:

Upper part... .... .... .. 7 3.0 28.6 0 2.7 .3

Middle part................. 5 3.0 20.0 20.0 2.2 .4

Lower part...------.---..-. 5 4.6 20.0 0 4.4 .2

Sharon Springs Member,-.-..-. 3 2.0 33.3 0 1.3 .7

Gammon Ferruginous Member. 2 4.5 0 0 4.5 0

0.2 46.0

.1 18.0

.7 1.8

.4

0

0

0

9.3

5.5

22.0

2.0

0

0.03 

.01 

.09

.15

0

0

0

 Based on number of species, not number of specimens.

arenaceous Foraminifera, in terms of both number of 

specimens and number of species (table 1). Identifiable specimens of calcareous-walled Foraminifera were 

present in only a few samples.

However, many samples that yielded no intact 

calcareous-walled specimens did contain partial or 

complete internal molds of presumably calcareouswalled specimens preserved as pyrite (see fig. 15), and 

most seemed to represent buliminid specimens. Preservation of large-chambered buliminids seems to be 

preferential, and therefore the composition of the 

original fauna cannot be known. Because of this uncertainty, the paleoenvironment could not be satisfactorily deduced on the basis of Red Bird foraminiferal 

evidence.1

Table 1 summarizes relationships between foraminiferal faunal elements (excluding internal molds) 

from the Pierre Shale at Red Bird. The very low 

representation of planktonic specimens and species 

and the simple internal structure of the arenaceous 

species suggest that deposition was not at bathyal or 

abyssal depths. The fine grain size of the sediment 

suggests deposition in a relatively low energy setting, 

and regional geological evidence indicates deposition 

of most of, if not all, the Pierre at a distance at least 

60 miles from shore. Thus, available evidence suggests 

that deposition occurred at water depths similar to 

those over Holocene continental shelves.

Although the Red Bird faunas cannot confidently 

be considered among them, largely or wholly arenaceous faunas were reported a number of times from 

deposits of the Cretaceous interior seaway. These 

faunas were reported by Tappan (1962) from the 

Cretaceous of Alaska; by Eicher (1960, 1965, 1966, 

1967) from the Cretaceous of the western interior of 

the United States; and by Stelck, Wall, Bahan, and 

Martin (1956), Wall (1967b), Stelck and Wall (1954, 

1955), Wall (1960), Wall and Germundson (1963), 

Mellon and Wall (1956), and Stelck, Wall, and 

Wetter (1958) from the Cretaceous of Canada. Three 

general environmental interpretations based on the 

arenaceous character of these faunas were made: (1) 

the water was of less than normal salinity and shallow, 

(2) the water was cold, or (3) the faunas lived at 

considerable depth. In some of the cited papers, especially Tappan (1962), further discussion of possible 

paleoenvironmental controls is offered, but it seems 

fair to say that all interpretations are based directly 

on analogy with Holocene conditions, and little atten-

*Use of terms such as "Red Bird foraminiferal fauna" or "Red 

Bird Foraminifera" is not meant to refer exclusively to the Red Bird 

Silty Member. Unless otherwise specified, their use will have wider 

meaning depending on the context.
FORAMINIFERA AT RED BIRD, WYOMING C5

tion is paid to lines of evidence, other than the foraminiferal, that might bear on the interpretation of 

environment. In my opinion, however, sufficient information is now available on Holocene foraminiferal 

distribution to throw serious doubt on each of these 

general interpretations.

Does Holocene environmental evidence support a 

shallow-water reduced-salinity environment for these 

largely arenaceous Cretaceous faunas? Phleger (1960, 

p. 149, 150) listed the species found in some lagoons, 

estuaries, and marshes, most of which have salinities 

below normal. Calcareous species were present in all 

lagoons and were more numerous than arenaceous 

species in four of the five lagoons. Calcareous species 

were also present in two of three estuary assemblages 

and in three of four of Phleger's marsh assemblages, 

although fewer in number than arenaceous species in 

both environments. Holocene assemblages dominated 

by arenaceous Foraminifera in environments of lowered salinity are areally restricted. In contrast, such 

Cretaceous assemblages are known over wide areas for 

the Thermopolis Shale (Eicher, 1960) and for the 

Graneros Shale (Eicher, 1965). If lowered salinity is 

used as an explanation for such assemblages, based 

on Holocene distributions, it seems logical to require 

that the total environment containing such assemblages be inferred for pertinent areas of the Cretaceous seaway. A very large and persistent marsh or 

estuary would serve as the environment of deposition, 

but when all geologic and paleontologic evidence is 

considered, both marsh and estuary seem very unlikely.

I cannot positively state that lowered salinity, 

coupled with a lack of tolerant calcareous species like 

those that evolved in the Tertiary and inhabit Holocene lagoons, was not the main environmental factor 

governing faunal composition. The tie, however, between the Cretaceous assemblages and the lowered 

salinity environments that harbor even grossly similar 

assemblages today does seem tenuous, and the adoption 

of a single environmental factor characteristic of those 

environments to explain the relationship is open to 

very serious doubt.

Several authors cited cold-water temperature as a 

possible environmental control promoting largely or 

exclusively arenaceous foraminiferal assemblages. Leslie (1965), in a study on the ecology of Holocene 

Foraminifera from Hudson Bay, showed that diverse 

calcareous near-shore faunas live most of the year in 

water temperatures as low (about 0°C) as those in 

which dominantly arenaceous assemblages live in 

deeper water. Temperature, in conjunction with other 

environmental factors, undoubtedly has an effect on

the foraminiferal population, but the presence of calcareous species in extremely cold water makes untenable the interpretation of the Cretaceous arenaceous 

foraminiferal assemblages as cold-water assemblages 

because of the absence of calcareous species.

Finally, several authors inferred a deep-water origin 

for arenaceous foraminiferal assemblages. Such inferences are on firmer ground at the outset than are those 

used in the other interpretations because they rely on 

the observed fact that assemblages dominated by 

arenaceous specimens do occur in Holocene deep-water 

environments, without attempting to relate this occurrence to any one environmental parameter. In open 

ocean areas, the largely arenaceous continental slope 

and bathyal assemblages are usually associated with 

large numbers of planktonic specimens. In Hudson 

Bay (Leslie, 1965), planktonic specimens are scarce 

and localized, and faunas that consist of 80-90 percent 

arenaceous specimens are in water 50-200 meters deep. 

According to Bandy and Arnal (1960, p. 1925), deepwater arenaceous species in Holocene oceans tend to 

have complicated interior structures. Species with such 

structures are absent throughout the deposits of the 

Cretaceous seaway.

In summary, analogies with the Holocene based on 

very few or very general criteria are not reliable in 

the interpretation of the living environments of Cretaceous foraminiferal faunas composed largely or 

completely of arenaceous specimens.

INTERPRETATIONS BASED ON MACROFOSSILS

Macrofossil collections at Ked Bird were made 

almost exclusively from concretion horizons. Comparison of foraminiferal faunas with these collections is 

limited in several ways. Fossiliferous concretions are 

sandwiched between shale layers, which are immediately juxtaposed where concretions are absent, so that 

the exact time interval represented by the concretions 

is apparently not represented in the shale. The postdepositional geochemical history of these two distinct 

lithologies is almost certainly different; therefore, the 

extent to which original faunas are represented in 

these lithologies is probably different. Post-mortem 

transport, which obviously took place before the preservation of macrofossils in some concretions, cannot 

be documented for foraminiferal assemblages, and the 

distances of such transport cannot be determined. 

Despite differences in preservational history, attempts 

were made to discover parallels in macrofossil and 

microfossil assemblages which might throw light on 

paleoenvironments. The number of macrofossil species 

of all types reported by Gill and Cobban (1966,
C6 DESCRIPTIVE STUDY OF A CLASSIC REFERENCE LOCALITY OF THE PIERRE SHALE

p. A50-A62) from each numbered collecting locality 

was plotted against the number of foraminiferal species from the same stratigraphic interval. No parallel 

trends between number of macrofossil species and 

number of foraminiferal species from samples stratigraphically near the macrofossil collecting sites were 

observed. There is an increase in the average number 

of species of macrofossils (table 2) per collecting horizon from the bottom of the Pierre Shale to the top, 

the highest average being in the upper unnamed shale 

member. The Foraminifera have no apparent trend 

but show a distinct separation between the upper and 

lower parts of the Pierre in terms of average number 

of species per sample in a unit (table 1 and fig. IB).

TABLE 2. Sizes and comparisons of macrofossil 

collections

[Collections taken from a single horizon or through shor* 

stratigraphic intervals are considered as one collection 

In this summary based on Gill and Cobban (1966)]

Stratigraphic unit

Upper unnamed shale member. .... 

Lower unnamed shale member. ....

Mitten Black Shale Member:

Middle part....................

a

8

2-|

 pjl

0 O

fc

21 

36

«4

15

2

6

1

CO .2

8 

a

"3 fl i§gf

to S3 So 03

c«-S J

31

24

13

6

5

3

?,

jg

a

<=«

tH O

ll$i

IsS-S

00

1 1

1

2

2

1

2

8

S 

a

O co

9§

2 <s

t*-5 "

6.4 

4.9

4.1

3.7

3.5

2.0

2.0

The stratigraphic and assemblage relationships of 

the macrofossils were considered by Dr. Erie Kauffman, U.S. National Museum, and his conclusions are 

summarized below. Functional morphology and analogy with the distribution of genetically related forms 

in the Holocene were used in this analysis. He concluded (written commun., 1967) that the Pierre Shale 

at Red Bird was probably deposited in normally 

saline waters at depths similar to those over the 

modern continental shelves. A diagrammatic representation of probable water depths is shown in figure lA. 

The Gammon Ferruginous Member yielded no macrofossils. The Sharon Springs Member is interpreted to 

have been deposited at middle to outer shelf depths, 

probably in cold waters or on bottoms that were 

toxic or oxygen deficient, or both. Shallowing during 

deposition of the upper part of the Mitten Black Shale 

Member, culminating in shallow-water deposition for 

the Red Bird Silty Member, was accompanied by 

warming of the water or transition to more hospitable 

bottom conditions or both. Moderate deepening is

indicated during deposition of the lower unnamed 

member, and shoaling is indicated during deposition 

of the upper part of the upper unnamed member, 

culminating in the shallow-water deposition of the 

Fox Hills Sandstone.

There is no discernible reflection of these inferred 

depth changes in the foraminiferal faunas. The upper 

part of the Mitten Member, the lower part of the 

lower unnamed member, and the middle or upper 

part of the upper unnamed member should have been 

deposited at similar depths, but there is no recurrence of foraminiferal species assemblages for these 

intervals.

Similarly, the Red Bird. Silty Member and the 

upper part of the upper unnamed member should have 

been deposited at the same depths, but this is not 

reflected in the foraminiferal faunas. Parts B and G 

of figure 1 show that total number of species per sample, the number of arenaceous, calcareous benthonic, 

and planktonic species per sample, and the approximate percentage of arenaceous, calcareous benthonic, 

and planktonic specimens per sample. Most of these 

relationships are averaged for the lithologic units in 

table 1. Again, there is no convincing correlation 

between the relationships and the depth pattern 

inferred from the macrofossils.

Figure IB shows that the number of species per sample increases at the base of the Red Bird Silty Member. With some reversions to fewer species, this faunal 

diversity remains generally high to the upper part 

of the upper unnamed member. Also, the number of 

calcareous specimens is very low throughout the section except for several samples in the Red Bird Silty 

Member and single samples in the Gammon Member 

and in the middle and upper parts of the Mitten 

Member. The relationship, if any, between these patterns and regional geologic, lithologic, or macrofossil 

environmental evidence is not apparent.

COMPARISON OF FORAMINIFERAL FAUNAS 

BETWEEN THE STRATIGRAPHIC UNITS

Foraminiferal faunas recovered from the upper part 

of the Mitten Member and units below it contained 

only one-half to two-thirds as many species in an 

average sample as were found in the Red Bird Silty 

Member and younger units. This increase was largely 

due to an increase of arenaceous species. Only in the 

Red Bird Silty Member did the average number of 

calcareous benthonic species in a sample exceed 0.7 

and the average number of planktonic species in a 

sample exceed 0.4. Planktonic species occurred in each 

of the unnamed members and in the Red Bird Silty
FORAMINIFERA AT RED BIRD, WYOMING C7

Member, but below the Ked Bird Silty Member they 

were found only in the middle part of the Mitten 

Member. The Ked Bird Silty Member yielded a 

greater percentage of samples that contained calcareous benthonic and planktonic species than did any 

other unit; this is consistent with the greater frequency 

of occurrence of both these kinds of Foraminifera in 

an average sample. In summary, the percentages in 

table 1 show that the upper unnamed member, lower 

unnamed member, and Red Bird Silty Member are 

more like each other in most respects than they are 

like any one of the underlying Pierre units. Likewise, 

the units from the upper part of the Mitten Member 

to the Gammon Member seem to resemble each other 

rather closely in all the averaged parameters.

VERTICAL DISTRIBUTION AND 

BIOSTRATIGRAPHY

The distribution and estimated abundances of all 

species and samples studied are shown in table 3. 

Table 4 shows the range of each species and the percentage of samples from each unit in which each 

species occurs. Of the 61 species depicted, 33 occurred 

in one formation only. Twenty of these 33 occurred in 

only one sample each, nine occurred in two samples 

each, and none of the remaining species restricted to 

a single unit occurred in more than 22 percent of the 

samples from that unit. Only indeterminate specimens 

of Haplophragmoides occurred in all units, and only 

Bathy siphon brosgei and Saccammina complanata 

range from the Gammon Ferruginous Member to the 

upper unnamed shale member. Of the remaining 25 

species, three stand out as occurring in all units within 

their ranges and in a high proportion of the samples 

in these units: Glomospi/rella inconstans, Dorothia 

smokyensis, and Haplophragmoides excavata. The 

ranges of these species and of nine others that have 

relatively restricted ranges and that occur frequently 

within their ranges are shown in figure 2. Because of 

their frequency of occurrence within restricted ranges, 

these 12 species are theoretically best suited for use 

in biostratigraphically subdividing the Pierre Shale.

Included among these 12 species are Verneuilmoides 

cf. V. perplexus, Trochammina cf. T. wetteri, T. diagonis, Lagenammina difflMgiformis, Haplophragmoides 

excavata s. 1., and Textularia sp. 1 which are commonly not well preserved in the samples from the 

Red Bird area. If this poor preservation is characteristic of these species, their recognition elsewhere will 

be seriously impaired.

The scarcity of easily identifiable species that are 

restricted in range and that occur in most samples

within their ranges makes it unwise to formally subdivide the Pierre Shale into foraminiferal zones at 

this time. Figure 3 compares the ranges of the species 

occurring at Red Bird with their ranges elsewhere in 

the western interior. The ranges of most species at Red 

Bird are less than their cumulative ranges in the western interior. More work on Pierre Shale and ageequivalent foraminiferal faunas is needed before much 

confidence can be placed on foraminiferal biostratigraphic subdivisions applicable within either the western interior region of the United States or within the 

entire interior seaway.

A broad-scale biostratigraphic study of Cretaceous 

Foraminifera in Canada was presented by Wall 

(1967a). Of the zones recognized by him, only that of 

Trochammina ribstonensis seems to be represented at 

Red Bird. Two of the five species that Wall listed as 

conspicuous in this zone are found together at Red 

Bird: Trochammina ribstonensis and Dorothia smokyensis. These two species are especially common in the 

lower part of the Mitten Member at Red Bird, and 

there is a possible occurrence in the upper part of the 

Mitten.

Dorothia smokyensis is more commonly represented 

and very abundant in the upper half of its local range, 

which extends to the upper part of the upper unnamed 

shale member. Trochammma ribstonensis was also reported from rocks of late Campanian and early 

Maestrichtian ages in the interior seaway, and its 

presence suggests that environmental controls, possibly 

the fairly shallow probably somewhat turbid environment suggested by Wall (1967a, p. 190), are responsible for the restricted range of this species in some 

areas. The T. ribstonensis fauna of the Rocky Mountain foothills of Canada occurs in rocks of late 

Santonian and early Campanian age, slightly older 

than the strata containing T. ribstonensis and D. 

smokyensis at Red Bird.

PROBLEMS IN THE STUDY OF FORAMINIFERA 

OF WESTERN INTERIOR UNITED STATES

Nearly all specimens of Haplophragmoides, the 

most abundantly represented genus in the Red Bird 

samples, Trochammina, and species of several other 

genera were distorted during compaction of the enclosing sediment. Distortion of form is common to many 

agglutinated Cretaceous species from the western 

interior and is probably due to an original flexibility 

of the wall. Study of distorted specimens is difficult 

because of the varied shapes secondarily imposed on 

specimens of the same species and because of the concomitant loss of detail, especially apertural detail.
C8 DESCRIPTIVE STUDY OF A CLASSIC REFERENCE LOCALITY OF THE PIERRE SHALE

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FORAMINIFERA AT RED BIRD, WYOMING C9

~~\ i i i i i i i i i r
Members

of Pierre

Shale

Middle 

part

Sharon 

Springs 

Member

TABLE 3. Ranges and relative abundances of foraminiferal species Continued
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Tappan brosgei IBathysiphon 

1 sp. Haplophragmoides 

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1 sp. Textularia 

Nauss vitta Bathysiphon 

Plummer carseyae IBuliminella 

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and Cushman canadensis Neobulimina 

alpha var. Wickenden 

Mello inconstant Glomospiretta 

Wall smokyensis Dorothia 

Wickenden ribstonensis Trochammina 

sp. Ammobaculoidesl 

sp. Rugoglobigerinal 

Pessagno prairiehiUensis Globigerinelloides 

and Cushman excavata Haplophragmoides 

1. s. Waters 

and Cushman canadensis Neobulimina 

beta var. Wickenden 

(Schwager) coprolithiformis Ammobaculites 

and Cushman calcula Haplophragmoides 

Waters

(Reuss) girardana Gyroidina 

beaumontianus C. aff. sp. Cibicides 

(d'Orbigny)

1 sp. Gyroidina 

(Ehrenberg) globulosa Heterohelix 

A sp. sedis Incertae 

(Roemer) muensteri Lenticulina 

Mello meidamos Pseudoclavulinal 

1 sp. Stilostomella 

Brady) B. (H. difflugiformis Lagenammina 

1 sp. Reophax 

(Carsey) diagonis Trochammina 

(Cushman)? navarroana Neobulimina 

Bolin globosa Trochammina 

1 sp. Spiroplectammina 

1 sp. Pseudobolivinat 

Wall and Stelck wetteri T. cf. Trochammina 

Cole kickapooensis Bulimina 

australis Belford australis Alabamina 

Belford

(Jennings) pinguis Anomalinoides 

Mello? jarviseUus Astacolus 

Parker) and (Cushman vitrea Caucasina 

Cushman basiplanata Dentalina 

(d'Orbigny) graeilis D. cf. Dentalina 

Reuss legumen Dentalina 

(Alth) depressa Gyroidina 

(Reuss) apiculata Lagena 

Lamarck rotulata L. cf. Lenticulina 

Reuss obscura Nodosaria 

Mello obeliscata Oolina 

(d'Orbigny) triangularis Saracenaria 

Parker and Cushman spinosa Neobulimina 

A sp. Fissurina 

Cushman watersi Frondicularia 

(Brotzen) pulchra Heterohelix 

Parker) and (Jones charoides Glomospira 

2 sp. Haplophragmoides 

Asano futabaensis Silicosigmoilina 

Hofker taylorensis N. cf. Nonionella 

(Loeblich) perplexus V. cf. Verneuitinoides 

(Cushman) watersi Gaudryina 

(White) uUimatumida H. cf. Htterohelix 

Uushman texasensis M. . cf Marginulina 

in indet.s found 29ofthe from [Example: unnamed shl Haplophragmoidesl sp. percent samples upper member]

j,v aaa 'aaia no
C12 DESCRIPTIVE STUDY OF A CLASSIC REFERENCE LOCALITY OF THE PIERRE SHALE

aestrichtian

a

 

Campanian

Upper

unnamed

shale

member

yKara Bentoni-/ 

\tic Member/

Lower

unnamed

shale

member

Red Bird 

Silty Member

a * 

? s

Upper part

Middle part

Lower part

Sharon Springs 

Member

G immon

Ferruginous 

Member

\

; = i :

1-

: !

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|.'

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1 , ,

i I

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 :.:.:.'-- r:

. ].. i ..:...

...,..--.

FlGCRE 3- -Ranges of foraminiferal species in the Pierre Shale at Red Bird, Wyo., and their composite ranges from elsewhere in the Cretaceous

interior seaway.
FORAMINIFERA AT RED BIRD, WYOMING C13

3 e.

.ts °> 5 s

t£ -C

£ s

EXPLANATION

Range in Pierre Shale 

at Red Bird, Wyo.

Composite range from elsewhere in the

Cretaceous interior seaway 

Includes all available data from Alaska, 

Canada, and the western interior of the 

United States
C14 DESCRIPTIVE STUDY OF A CLASSIC REFERENCE LOCALITY OF THE PIERRE SHALE

In practice, I found that almost total dependence for 

discrimination between specimens of different species 

must often be placed on features that are of low or 

doubtful diagnostic significance.

The characters most generally used in the study of 

the agglutinated Ked Bird specimens were:

1. Number of chambers or range of numbers of chambers in the final whorl and any other visible 

whorls of coiled specimens. This number is usually fairly easily determined, but in itself is of 

little practical use unless the number is unusually 

large or small.

2. Chamber size and shape. This character is difficult 

to determine in many specimens that have been 

badly distorted.

3. Size of agglutinated particles and smoothness of 

the test wall. These features are little affected by 

distortion, but suites of otherwise similar specimens have shown large variations in these characters so that they, too, must be considered of 

limited value.

4. Degree of involution and height of spire in coiled 

specimens. These features are difficult to assess 

in many distorted specimens, though they are 

generally discernible and useful.

5. Color of the wall and specimen size. Both these 

characters have been found to vary, as would be 

expected, and are of limited value. 

The lack of precision inherent in the above characters, 

even when it is possible to use some or all collectively, 

makes identification of many of the agglutinated Red 

Bird specimens more than normally subjective.

During this study generic determinations were made 

for all specimens as the first step in taxon identification. Then a search was made among the specimens 

assigned to each genus, and, using the criteria discussed above, groups of the best preserved specimens 

having the same characters were set aside for reference purposes. Comparison was then made between 

each occurrence of that genus in the samples and the 

groups of reference specimens which were set aside. 

This process resulted in: (1) the separation of other 

apparently distinct groups, representatives of which 

were chosen and set aside for reference purposes, and 

(2) the combination of previously separated groups 

where specimens intermediate in character were found. 

Then all specimens assigned to a particular group 

were critically compared with each other, doubtful 

specimens were removed from the group, and descriptions were written for each of the groups (now considered as species). Comparisons were made with the 

descriptions, figures, and available type specimens of

previously described Cretaceous species from the 

western interior and Gulf Coastal Plain. Typological 

methodology prevailed in the erection of most western 

interior and Gulf Coastal Plain foraminiferal species. 

As a result, sometimes several names were applicable 

to various distortions of single arenaceous species, and 

usually no data are given on ranges of morphologic 

variation. In this study, all available type and 

comparative specimens of similar species were examined, and variations in the Eed Bird specimens are 

described.

STRATIGRAPHIC POSITIONS OF THE SAMPLES

Spot samples were taken in the field at approximately 10-foot stratigraphic intervals throughout most 

of the section, except where exposures were too poor 

to permit collection of relatively fresh shale, and 

throughout the Gammon and Sharon Springs Members, where collections were made at 5-foot intervals. 

Samples were collected along traverses A and B of 

Gill and Cobban (1966, p. A5 and pi. 1); the relation 

to these traverses and to the detailed section description by Gill and Cobban (1966, p. A49-A62) is shown 

in table 5.

TABLE 5. Strategic positions of the samples 

[Traverse and unit numbers from Gill and Cobban (1966)]

Foraminiferal 

sample 

No.

Member or Tra- Unit 

formation verse No.

Position

76.......... Fox Hills

Sandstone. 

75....___ Upper unnamed

shale member.

74___ do-... 

73...... ... .do...........

72...... ........do -

71...-.- ......do .. -

70.. do 

-do.

-do.

-do. 

.do. 

_do.

-do. 

.do-

-do. 

.do.

67.... .

66........

65__ 

64........

63........

62........

61........

60....___ Lower unnamed

shale member. 

59.... do .

58...............do -- 

57...............do ... 

56___ _..._. do -. 

55....... .....do ..-. -.

54............... do .........

53...... ......do. ...--.

52...............do .

51...............do ... -.

50....... .....do ..... .

49...... ......do. ........

48...............do 

47...... .....do .... 

46...............do ---

45.-..- ..-.do .........

44...............do. ---.

43.... ..do 

42.......... Red Bird SUty

Member. 

41......-. do ------

40 -.-.. do .. --------

39... ......do.... 

38... .......do..... 

37... .....do... 

A 114 3 ft. 6 in. above base of unit.

B 110 3 ft. 0 in. above base of unit.

B 107 From upper 10 ft. of unit.

B 106 From lower 5 ft. of unit.

B 103 From lower 15 ft. of unit.

B 101 From 25-35 ft. above base of unit.

B 98 From immediately below bento-

	nite of unit 99.

B 98 From 5-10 ft. above base of unit.

B 96 From lower 10 ft. of unit.

B 94 From 5-15 ft. below top of unit.

B 92 From upper 10 ft. of unit.

B 91 From upper 10 ft. of unit.

B 91 About 15 ft. above the base of unit.

B 88 F rom upper 5 ft. of unit.

B 86 8 ft. below top of unit.

B 86 10 ft. above base of unit.

B 81 From upper 1 ft. of unit.

B 80 At top of unit.

B 79 From 40-45 ft. above base of unit.

B 79 Within 5 ft. above base of unit.

B 77 From 10-20 ft. above base of unit.

B 75 From 25-30 ft. above base of unit.

B 72 From top 6 in. of unit.

B 70 From 10-12 ft. above base of unit.

B 66 From upper 3 ft. of unit.

B 64 From 5-15 ft. above base of unit.

B 61 About 20 ft .above base of unit.

B 59 From upper 5 ft. of unit.

B 58 From 80-90 ft. above base of unit.

B 58 From 40-50 ft. above base of unit.

B 58 From basal 5 ft. of unit.

B 57 Fromabout25ft.abovebaseofunit.

B 55 From 50 ft. above base of unit.

B 55 From 8-10 ft. above base of unit.

B 53 From 15-20 ft. above base of unit.

B 51 From top 6 in. of unit.

B 51 About 37ft. above base of unit.

B 51 About 28 ft. above base of unit.

B 51 About 20 ft. above base of unit.

B 50 About 28-30 ft. above base of unit.
FORAMINIFERA AT RED BIRD, WYOMING C15

TABLE 5. Strategic positions of the samples Continued

Foraminiferal

sample

No.

36.. ....... .

36.. ........

34..........

33.. ....... .

32..........

31. .. .

SO..........

29... 

28- -.

27.. .. ......

26. 

25 __ .......

24. .

23.. ........

22... ..

21. ... ......

20- . 

19-. .

18. 

17.. 

16.. . 

15. 

14.. ........

13. 

12---. 

11-..- 

10. ...

9...... .... .

8.. .....

7.. ...

6...........

5.. ......

4......... .

3.. .........

2_ _ 

1-. .........

Member or

formation

Red Bird Silty

Member.

.... .do...... ..... .

 ..do..- 

..... do..... . -

 do.. 

..... do-.. . 

 do... - 

 do.. 

... ..do-.. 

..... do... -

 do.. ... ....

Shale Member.

 do.. 

 do.- 

 do. 

 do.. .

.. do... ... ...

 do.. .... ...

 do-. 

 .do. -

 .do.. ... ...

 do... ..

 do.. ..... .

..... do... ..

... ..do... ..

 do.. 

.... .do... ....

..-..do... ......

Member.

 do. 

 do... .... -

ginous Member.

Formation.

-...do.. .......

Traverse

B

B

B

B

B

B

B

B

B

B

B

B

B

B

B

B

B

B

B

A

A

A

A

A

A

A

A

B

B

B

B

B

B

B

B

B

Unit

No.

49

47

45

43

42

39

38

37

36

36

35

34

33

32

30

29

29

28

28

26

26

25

24

22

21

20

20

19

16

13

8

8

5

Position

About 20 ft. above base of unit.

About 26 ft. above base of unit.

unit.

unit.

Preliminary examination of samples showed that 

the foraminiferal faunas were small in number of 

specimens and low in variety of species, the same 

species recurring through many feet of section. Consequently, samples were selected for examination at 

approximately 50-foot intervals, intervening samples 

being examined whenever changes in the fauna seemed 

to warrant it. Seventy-three samples from the Pierre 

Shale, one from the lower part of the Fox Hills Sandstone, and two from the Niobrara Formation were 

examined.

Remeasurement of the section at Red Bird, which 

was carried out by Gill and Cobban after the collection of samples for Foraminifera, resulted in modifications in many unit thicknesses and in the number of 

units recognized. These modifications were included in 

the stratigraphic parts of the paper by Gill and Cobban (1966). Because of these changes, many of the 

samples could not be related to the precise levels from 

which they were collected. In such cases, the positions 

of the samples are indicated by reference to unit 

numbers and parts of the units from which they came.

SAMPLE PREPARATION

One hundred grams of each sample was boiled in a 

solution of washing soda and water until satisfactory

breakdown was achieved and then washed through a 

200-mesh sieve. For many samples, breakdown was incomplete. As a result, the weights of the washed residues 

do not reflect original amounts of sand-size grains, and 

these values are not included here. After they were 

dried, most samples were sieved on 60-, 100-, 150-, and 

200-mesh sieves. Approximately equal volumes of sediment were examined from all sieves. Estimates were 

made of the total number of specimens of each species 

in each sample, and each estimate was further generalized into one of the following categories:

Category Specimens and symbol

Exclusive __________ 1 (X)

Scarce ______________ 2-3 (S)

Very rare___________ 4-9 (VR)

Bare ______________- 10-19 (B)

Bather rare___________ 20-49 (BB)

Bather common________ 50-149 (BC)

Common _____________ 150-^99 (C)

Very common___________ 500-1,000 (VC)

Abundant ____________ >1,000 (A)

SYSTEMATIC PALEONTOLOGY

Genus ALABAMINA Toulmin, 1941

Alabamina australis Belford australis Belford

Plate 1, figures 1-3

Alabamina australis Belford australis Belford, 1960, Australia

Bur. Mineral Besources, Geology and Geophysics Bull.

57, p. 84, pi. 23, figs. 13-20, text fig. 4, figs, 1-4 on text

fig. 5. 

? Eponides sp., North and Caldwell, 1964, Saskatchewan Besearch Council, Geology Div. Bept. 5, p. 24, pi. 4, figs.

7a-c.

Description. Test low trochospiral, partially evolute on spiral side, completely involute on umbilical 

side, with a very shallow and small umbilicus, spiral 

side slightly convex to slightly concave, umbilical side 

moderately convex, equatorial periphery smooth or 

slightly indented at suture lines, axial periphery rather 

broadly rounded and lacks an imperforate band. 

Chambers somewhat inflated, closely appressed, five 

or six, generally six, in the final whorl, increasing 

fairly regularly and moderately in size as added; in 

spiral side view, chambers obliquely arranged with 

respect to the axis of coiling, degree of obliquity often 

variable from one chamber to the next, resulting in 

wedge-shaped to trapezium-shaped chambers; in umbilical side view, chambers shaped like abruptly tapering wedges. Sutures on spiral side slightly to 

markedly oblique, slightly convex forward, slightly 

or not at all depressed, becoming slightly limbate 

toward the axis of coiling; sutures on umbilical side 

radial or slightly oblique, straight, slightly depressed; 

spiral suture not smooth, the sum of each chamber's
C16 DESCRIPTIVE STUDY OF A CLASSIC REFERENCE LOCALITY OF THE PIERRE SHALE

straight or slightly curved increment. Wall has unclear 

microstmcture, probably granular, rather thin, white, 

somewhat translucent, smoothly finished, unornamented, polished, very finely perforate. Aperture an interiomarginal opening bordered above by a slight 

thickening of the septal face and extends on some 

specimens from the umbilicus nearly to the periphery; 

peripheral part slightly arched and abuts against the 

peripheral side of a slightly to moderately pronounced 

indentation of the septal face; the part of the aperture extending from the arched subperipheral part 

nearly to the umbilicus is a low slit which is closed in 

some specimens; the umbilical part of the aperture is 

represented by a short wedge-shaped slit which widens toward the umbilical tip of the chamber and which 

is not closed on the final chamber.

Dimensions. Specimens of average size range from 

0.2-0.35 mm in maximum diameter.

Remarks. Only a few of the Red Bird specimens 

preserve the apertural area, so it is impossible to document better the apertural features noted above. In 

order to clarify the nature of the surficial indentation of the peripheral margin of the apertural face, 

the umbilical walls of several chambers were dissolved 

away. Internally there is a downward-plunging structure shaped like a funnel compressed in the plane of 

coiling and extending along the top of the underlving 

chamber to about midway between the septae. This 

structure lies to the peripheral side of the end of the 

aperture. The indented surface of the apertural face 

to which the large end of the structure is attached is 

closed off a short distance from the level of the rest 

of the apertural face; in other words, the indented 

surface of the apertural face does not open into this 

internal structure, if, indeed, it is hollow inside. 

According to Brotzen (1948, p. 97-103), who gives 

considerably more information on this structure in 

Alabamina, the base of the structure is open against 

the top of the underlying chamber.

The Red Bird specimens bear resemblance to two 

previously described species of Alabamina. A. dorsoplana (Brotzen) is similar in having a flat or slightly 

convex spiral side and quite convex umbilical side, 

but it differs importantly in having a much more protrudent peripheral extension of the final chamber 

("tectum" in Brotzen's terminology), a higher aperture, and a more sharply angled periphery. A. australis australis Belford is similar in having a broadly 

rounded periphery, flat spiral surface, evolute spiral 

side, and aperture extending to the umbilicus. A point 

of difference is that Belford's specimens generally 

have five rather than six chambers in the final whorl. 

Belford (1960, p. 84) described the internal "toothplate" as solid in his subspecies, in contrast to the 

hollow nature of this structure as reported by Brotzen 

(1948). The extremely small size of this structure in 

the Red Bird specimens makes it impossible to determine whether it is hollow or solid.

No comparative specimens of A. australis australis 

were seen, but the excellent agreement of the Red Bird 

specimens with the descriptions and figures of this subspecies in almost every particular indicates that they 

are the same.

North and Caldwell (1964, p. 24, pi. 4, figs. 7a-c) 

described and illustrated a form they referred to as 

Eponides sp., which may be conspecific with A. australis 

australis, but there are sufficient points of difference in 

their description to make this synonymization tentative.

Occurrence and range. A. australis australis has 

been reported only once previously, from Santonian 

beds of Australia (Belford, 1960, p. 84).

Genus AMMOBACTTLITES Cushman, 1910

Ammobaculites coprolithifonnis (Schwager)

Plate 1, figure 11

Haplophraffmium coprolithiforme Schwager, 1868, Benecke's

Geogn.-paleont. Beitrage, v. 1, p. 654, pi. 34, fig. 3. 

Ammobaculites coprolithiforme (Schwager). Cushman, 1927,

Royal Soc. Canada Trans., 3d ser., v. 21, sec. 4, p. 130,

pi. 1, figs. 6, 7. 

Ammobaculites coprolithiformis (Schwager) Cushman and

Deaderick, 1942, Cushman Lab. Foram. Research Contr.,

v. 18, p. 51, pi. 9, fig. 9. 

Cushman and Deaderick, 1944, Jour. Paleontology, v. 18,

no. 4, p. 328, pi. 50, fig. 2.

Description. Test has a small initial coil of four 

to six chambers, later becomes uniserial, straight or 

very slightly arched, uniserial part consists of as many 

as six chambers, tapering gradually to the initial coil, 

has a short, fairly broad, terminal or slightly eccentric 

apertural extension. Chambers somewhat inflated, generally slightly higher than wide, as wide as high in 

some specimens, slightly overlapping, increasing very 

gradually and rather regularly in size as added, 

collapsed in many specimens. Sutures perpendicular 

or very nearly so to the axis of elongation, generally 

slightly to moderately depressed but considerably 

depressed in some specimens, indistinct where slightly 

depressed because of granularity of the wall. Wall 

rather thick, composed mostly of grains of intermediate to large size set close together in white to 

light-brown noncalcareous cement, surface smooth to 

moderately rough textured, nearly all grains are 

quartz; some specimens show considerable differences 

in grain size from one chamber to the next. Aperture
FORAMINIFERA AT RED BIRD, WYOMING C17

a small subrounded opening at the end of the slightly 

produced apertural neck, neck missing on some specimens, presumably because of breakage, and aperture 

not discernible in many specimens.

Dimensions. Specimens of average size are about 

0.5 mm long and about 0.2 mm wide.

Remarks. When preserved the apertural neck is 

short. In most specimens it tapers slightly from its 

broad base to its rather broad end. In other specimens 

the apertural neck is much narrower throughout and 

is composed of much finer grains. The Red Bird specimens assigned to Ammobaculites coprolithiformis are 

closely similar to specimens from the Marlbrook Marl 

and Brownstown Marl of Arkansas illustrated by 

Cushman and Deaderick (1942, pi. 9, fig. 9; 1944, 

pi. 50, fig. 2). Considerable latitude has been taken 

by Cushman and by other American workers in the 

Cretaceous in assigning specimens to this species. No 

detailed study of the variation shown by suites of 

specimens has been made. Unfortunately, the Red Bird 

specimens are too poorly preserved and too scarce to 

support such a study.

Among other species of Ammobaculites that have 

previously been reported from the Montana Group 

and equivalent rocks in North America exclusive of 

the gulf coast, A. fragmentarius Cushman most closely 

resembles the Red Bird specimens but differs in generally having more chambers per specimen and in 

being more tapered. A. texanus Cushman and A. 

stephensoni Cushman have much more pronounced 

initial coils than the Red Bird specimens, which have 

a single coil of four to six small chambers which 

externally resemble a partially compressed large proloculus. This latter characteristic and the frequent 

absence of the earliest part of the test make confusion 

between A. coprolithiformis and Reophax possible.

Occurrence and range. Ammobaculites coprolithiformis has been reported from rocks of early to 

middle Campanian age from southwest Wyoming 

by Gauger (in Jones, 1953, p. 55) and, with question, from south-central Alaska by Bergquist (1961, 

p. 2005).

Genus AMMOBACTTLOIDES Plummer, 1932

Ammobaculoides? sp.

Plate 1, figure 4

Remarks. A small group of poorly preserved specimens are questionably placed in Ammobaculoides. 

Most specimens consist only of the initial planispirally 

coiled stage, 0.15-0.18 mm in diameter, composed of 

five to seven chambers. Three specimens develop the

linear stage (as many as five chambers) which appears 

to be loosely biserial throughout. The test is collapsed 

or distorted on all specimens and is composed of 

quartz grains, large in proportion to test size, embedded in a small amount of noncalcareous cement. 

This coarse grain size and the deformed condition of 

the specimens make it very difficult to observe sutures 

and chambers. The aperture was not observed.

Genus ANOMALINOIDES Brotzen, 1942

Anomalinoides pinguis (Jennings)

Plate 1, figure 5

Anomalina pinguis Jennings, 1936, Bull. Am. Paleontology, v.

23, no. 78, p. 37, pi. 5, fig. 1.

Anomalinoides pinguis (Jennings). Brotzen, 1948, Sveriges 

geol. undersokning, Arsbok 42, no. 2, ser. C, no. 493, p. 

86. 

Tappan, 1962, U.S. Geol. Survey Prof. Paper 236-C, p. 199,

pi. 58, figs. 2-5.

Bergquist, 1966, U.S. Geol. Survey Prof. Paper 302-D, p. 

119, 182, 215, 216.

Description. Test very low trochospiral, umbilical 

side convex, spiral side slightly convex in some specimens, especially smaller ones, planar to slightly concave in larger specimens, axial periphery rather 

abruptly rounded, has no keel, equatorial periphery 

smooth or has slightly to moderately pronounced 

indentations at the sutures, especially for the final 

three or four sutures, spiral side slightly evolute and 

has a central boss of clear shell material. Chambers 

wedge shaped, closely appressed, slightly to moderately inflated, eight to 10 in final whorl, increase regularly and gradually in size as added, except in some 

larger specimens where the final few chambers increase 

more abruptly in size over the preceding chambers. 

Sutures sometimes straight but usually slightly curved, 

commonly slightly oblique but occasionally radial, 

flush with the surface and strongly limbate in the early 

part of the final whorl of most specimens, less limbate 

and slightly depressed in the later part, coming 

together in a shallow depression on the umbilical side, 

joining the central boss of shell material on the spiral 

side. Wall granular in microstructure, with abundant 

coarse perforations many of which have been covered 

or filled in the earlier chambers of the final whorl. 

Aperture an interiomarginal opening extending from 

the umbilical side margin of the axial periphery to the 

edge of the boss of shell material on the spiral side 

and thence beneath the final three or four chambers, 

slightly arched and highest over the axial periphery
CIS DESCRIPTIVE STUDY OF A CLASSIC REFERENCE LOCALITY OF THE PIERRE SHALE

of the test, much lower and more slitlike on the spiral 

side, with a thin slightly protrudent lip above.

Dimensions. Greatest diameter of whorl about 0.38 

mm; maximum thickness parallel to coiling axis about 

0.16 mm.

Remarks. In the very brief original description of 

Anomalina pinguis, Jennings (1936, p. 37) reported 

eight to nine chambers in the final whorl, whereas the 

Eed Bird specimens have eight to 10, and the aperture 

is described as embracing the margin of the test, no 

mention being made of a slit extending to the spiral 

side. In other respects, Jennings' description fits the 

Eed Bird specimens very well, and the type figure is 

exactly similar to the spiral side view of these specimens. The poorly preserved plesiotype assigned to 

this species by Cushman (1944, p. 16) is about twice 

as large as the largest Red Bird specimen but is 

exactly similar in preserved morphologic characteristics. Anomalmoides pinguis is clearly distinct from 

other species of Anomalina and Anomalinoides reported from western interior, Canadian, or Alaskan 

deposits of Campanian or Maestrichtian ages.

Occurrence and range. Anomalinoides pinguis has 

been reported from the Santonian and Campanian of 

northern Alaska by Tappan (1962) and Bergquist 

(1966). There have been no reports of this species 

from equivalent or younger Cretaceous rocks of the 

western interior of Canada. The species has been 

reported from the Corsicana Marl and Pecan Gap 

Chalk of the gulf coast Cretaceous by Cushman (1946, 

p. 156), from the Navesink and Mount Laurel Formations of New Jersey by Jennings (1936, p. 37), and 

from the Eedbank Sand and the New Egypt Formation of Olsson (1959) in New Jersey by Olsson (1960, 

p. 51-52).

Genus ASTACOLUS de Montfort, 1808

Astacolus jarvisellus Hello?

Plate I, figure 6

MarginuUna jarvisi Cushman, 1938, Cushman Lab. Foram. Research Contr., v. 14, pt. 2, p. 35, pi. 5, figs. 17, 18.

Astacolus jarvisi (Cushman) [not Astacolus jarvisi Brotzen, 

1936]. Trujillo, 1960, Jour. Paleontology, v. 34, no. 2, 

p. 317, pi. 46, fig. 2.

Astacolus jarvisellus Mello, 1969, U.S. Geol. Survey Prof. Paper 

611, p. 57, pi. 6, figs. 4a, b.

Remarks. Two incomplete specimens have been 

assigned with question to this species. Characteristic 

features are the abrupt but unkeeled dorsal margin, 

the rather sharply rounded ventral margin which 

becomes progressively broader toward the apertural 

end, the partially coiled initial part involving the first

four or five chambers, the extension of all but the last 

few chambers to the proloculus on the ventral side, 

and the smooth, unornamented wall having flush or 

slightly depressed and very slightly curved sutures. 

These specimens closely resemble the holotype of 

A. jarvisellus and specimens of this species from the 

Pierre Shale of north-central South Dakota (Mello, 

1969, p. 57), but the absence of the apertural area in 

both of the Red Bird specimens makes positive identification impossible.

Occurrence and range. Mello (1969, p. 57) reported 

Astacolus jarvisellus from the lower part of the 

Mobridge Member of the Pierre Shale of late Campanian age. Cushman (1946, p. 63) reported this 

species from the Kemp Clay of Maestrichtian age in 

the gulf coast deposits.

Genus BATHYSIPHON M. Sars, 1872

Bathysiphon brosgei Tappan

Plate 1, figures 7-9

Bathysiphon brosgei Tappan, 1957, U.S. Natl. Mus. Bull. 215,

p. 202, pi. 65, figs. 1-5. 

Tappan, 1962, U.S. Geol. Survey Prof. Paper 236-C, p. 128,

pi. 29, figs. 1-5. 

Bergquist, 1966, U.S. Geol. Survey Prof. Paper 302-D,

p. 104. 

Mello, 1969, U.S. Geol. Survey Prof. Paper 611, p. 40, pi.

4, fig. 1.

Remarks. The test is an open tube, broken at both 

ends in all the Red Bird specimens, that has considerable variation in width, wall thickness, and wall composition. Almost all specimens are compressed; the 

width of compressed specimens varies from 1.20 to 

0.06 mm. The walls vary in thickness from 0.18 to 

0.01 mm, but this thickness does not seem to be a direct 

function of specimen size, based on width, though the 

narrower specimens generally have thinner walls than 

the wider specimens. Many specimens have irregularly 

spaced constrictions in the test perpendicular or nearly 

so to the axis of elongation, and most specimens have 

a channellike longitudinal central depression due to 

secondary compression of the test. The texture of the 

walls varies from smoothly finished and almost glassy, 

with a very few discernible grains immersed in the 

matrix, to very rough, with numerous quartz grains 

cemented together by a minor amount of matrix. Some 

specimens seem to be transitional between these two 

end members, having walls composed mainly of matrix 

but studded with numerous large protrudent quartz 

grains. Another more common intermediate wall structure is composed of numerous moderate-sized grains 

set in a moderate amount of matrix and having a
FORAMINIFERA AT RED BIRD, WYOMING C19

somewhat roughened surface texture. Although specimens of this species are not very common in the Ked 

Bird samples, those available do show transitions 

between the wall compositions cited above. Paratypes 

of Bathysiphon brosgei in the U.S. National Museum 

collections, to which the Ked Bird specimens were 

compared, show a variation in wall texture similar to 

that described for the Red Bird specimens except that 

none of the paratypes is so coarse grained as the 

coarsest grained Red Bird specimens.

The few specimens assigned to Bathysiphon vitta 

Nauss from the Red Bird samples are separated from 

specimens assigned to B. brosgei Tappan on the basis 

of the black coating present at least to some degree on 

specimens of B. vitta. If this coating is secondary, as 

seems likely, then there seems to be no morphologic 

basis for distinguishing these specimens from B. 

brosgei. The separation is maintained here, however, 

pending more definitive evidence from larger assemblages. Tappan (1962, p. 128) separated specimens 

which she referred to B. vitta from those she assigned 

to B. brosgei because B. brosgei is more slender and 

has a somewhat more roughened surface. Her first 

criterion is faulty because the widest specimens of 

B. vitta must have had narrower early stages. Her 

second criterion may be valid, although, as it is a 

matter only of degree, it must be carefully evaluated. 

In summary, it seems to me that the criteria originally 

used to set B. brosgei apart from B. vitta are open to 

question and that the reality of B. brosgei as a species 

distinguishable from B. vitta deserves further study. 

Samples and relative abundances. 

Fine-grained wall: 10-S, 11-X, 26-RR, 27-VR, 33-VR,

44-S, 54-R, 55-S, 58-VR, Gl-VR 

Medium-grained wall: 31-X, 36-X, 45-VR, 46-X,

52-S, 53-S, 57-S, 71-RR, 74-S 

Coarse-grained wall: 39-X, 60-R, 62-S, 65-S, 66-VR,

73-X 

Wall-type indeterminate: 3-X, 4-S, 15-VR, 17-X,

35-X, 37-X

Occurrence and range. Bathysiphon brosgei has 

been reported from rocks of early Albian to late Canipanian ages in northern Alaska by Tappan (1962, 

p. 128). It was also reported from northern Alaska by 

Tappan (1957, p. 202) and Bergquist (1966, p. 104) 

and from the late Campanian and early Maestrichtian 

parts of the Pierre Shale of South Dakota by Mello 

(1969, p. 40). The very brief descriptions and poor 

figures given by LeRoy and Schieltz (1958, p. 2453, 

fig. 8) for B. arenacea Cushman, B. aff. carapitanus 

Hedberg, and B. eocenica Cushman and Harris from 

the Sharon Springs Member of the Pierre Shale in

Colorado may well represent variations of B. brosgei 

as here recognized.

Bathysiphon vitta Nauss 

Plate 1, figure 10

Bathysiphon vitta Nauss, 1947, Jour. Paleontology, v. 21, no. 4,

p. 334, pi. 48, fig. 4. 

North and Caldwell, 1964, Saskatchewan Research Council,

Geology Div. Kept. 5, p. 10, pi. 1, figs. la-c. 

Wall, 1967b, Research Council Alberta Bull. 20, p. 38, pi. 7,

figs. 4-7.

Remarks. Six specimens from three samples are 

placed in this species. The specimens are compressed 

tubes having thick walls composed of minute grains 

set in a grayish-white matrix. There are few clearly 

distinct grains, but many smaller objects are thought 

to be grains, although they may be small rugosities 

composed of matrix. Two of the specimens are markedly wrinkled, probably a result of the distortion that 

caused their compression, and the illustrated specimen 

has an indistinct constriction near the middle. The 

most striking characteristic of these specimens is a 

dark surface coating. All specimens placed in this species have at least a trace of this coating, and one 

specimen is completely coated except at the ends and 

along cracks. Close examination of these coated surfaces shows that the coating is composed of many very 

fine blebs of brownish-black material, perhaps hydrotroilite. Along the cracks and at the broken ends of 

the specimens, this coating can be seen to be entirely 

surficial, the fine blebs being only on the outer surface 

of the test. In view of the surficial and probably 

secondary nature of this coating, its presence is probably not a valid morphologic criterion for separation 

of this species from Bathysiphon brosgei Tappan. 

However, because of the extreme morphologic simplicity of this genus and the variability in morphologic characters displayed by its species, I hesitate 

to synonymize B. vitta on the chance that the black 

coating was originally deposited by the organism. 

When large suites of specimens become available, the 

constancy of this black coating should be carefully 

evaluated. It should be noted that North and Caldwell 

(1964, p. 10) assigned many uncoated specimens to 

this species and did not regard this character as of 

diagnostic value.

Dimensions of largest specimen. Length (incomplete), 0.73 mm; width, (partially crushed), 0.41 mm.

Occurrence and range. Bathysiphon vitta was originally reported by Nauss (1947, p. 334) from the late 

Santonian and early Campanian Lea Park Shale of 

east-central Alberta, Canada. It has since been re-
C20 DESCRIPTIVE STUDY OF A CLASSIC REFERENCE LOCALITY OF THE PIERRE SHALE

ported from the same formation in south-central Saskatchewan (North and Caldwell, 1964, p. 10) and 

from Albian beds in northern Alaska (Tappan, 1962, 

p. 128).

Genus BTTLIMINA d'OrMgny, 1826

Bulimina kickapooensis Cole 

Plate 1, figure 14

Bulimina kickapooensis Cole, 1938, Florida Dept. Conserv.,

Geol. Dept. Bull. 16, p. 45, pi. 3, fig. 5. 

Bulimina kickapoocnsis Cole var. pingua Cushman and Parker,

1940, Cushman Lab. Foram. Research Contr., v. 16, pt. 2,

p. 44, pi. 8, figs. 13, 14. 

Bulimina kickapooensis Cole. Mello, 1969, U.S. Geol. Survey

Prof. Paper 611, p. 75, pi. 8, figs. 14, 15.

Remarks. This species is represented by fewer than 

10 whole specimens preserving original shell material, 

all of which are small and microspheric, and by about 

30 specimens which are either crushed, incomplete, 

or preserved as internal molds. Many of the second 

group can only be referred to this species with question. Bulimina kickapooensis is much more abundantly represented in the Pierre Shale of north-central 

South Dakota, as described by Mello (1969, p. 75). 

The better preserved Red Bird specimens are easily 

accommodated within the ranges of variation shown 

by the South Dakota specimens.

Occurrence and range. Cushman (1946, p. 123) reported Bulimina kickapooensis from beds of Austin, 

Taylor, and Navarro ages. In the western interior and 

Canada, it has been reported from the Hilliard Shale 

of southwest Wyoming of inferred middle and upper 

Campanian age (Gauger, in Jones, 1953, p. 79, pi. 9, 

fig. 16); from the Gregory Member of the Pierre Shale 

in North Dakota of middle Campanian age (Mello, in 

Gill and Cobban, 1965, p. A13); from the Virgin Creek, 

Mobridge, and Elk Butte Members of the Pierre Shale 

in South Dakota of late Campanian and early Maestrichtian age (Mello, 1969, p. 75) ; and from the Bearpaw Formation in southwestern Saskatchewan and 

southern Alberta of middle to late Campanian age 

(Loranger and Gleddie, 1953, fig. 3, p. 166).

Genus BTTLIMINELLA Cushman, 1911

TBuliminella carseyae Plummer

Plate 1, figures 12, 13

Buliminella carseyae Plummer, 1931, Texas Univ. Bull. 3101, 

p. 179, pi. 8, fig. 7.

Description. Test trochospiral, elongate, composed 

of as many as four whorls of three to 4i/£ chambers 

per whorl, most tests abruptly increasing in size after 

the first or second whorl; earliest part has

chambers per whorl, final one to ll/£ whorls generally 

greatly enlarged and composed of three to By2 chambers. Chambers of the final whorl inflated, overlapping 

much of the preceding whorl, each chamber embracing about half the preceding chamber, all chambers 

increasing regularly and moderately abruptly in size 

except for a very abrupt increase in size and degree of 

inflation in one whorl in most specimens. Sutures 

distinct except in earliest part, slightly depressed, intercameral sutures gently sinuous, spiral suture somewhat 

interrupted at chamber junctions but has a readily discernible spiral pattern. Walls smooth, generally glassy, 

unornamented, finely perforate, rather thick and 

opaque, although the final few chambers of some 

specimens are translucent and much thinner, apparently granular in microstructure. Aperture a curved, 

slot-shaped to oval opening extending from the base of 

the final chamber to one-half to two-thirds the height 

of the very low apertural face; generally set deeply 

in the apertural face and overhung at the top by the 

upper one-half to one-third of the apertural face, has 

a slightly thickened periphery on most specimens. 

Toothplate simple, a thick and apparently solid structure which extends from the inner or axial side of 

the aperture to the inner side of, but not into, the 

aperture of the penultimate chamber, has no surficial 

expression.

Dimensions. Maximum length, about 0.6 mm. Ratio 

of maximum length to maximum breadth ranges from 

1.44:1 for small specimens to 1.13:1 for large specimens.

Remarks. The Red Bird specimens are slightly to 

moderately broader than topotypes of Buliminella 

carseyae Plummer (Cushman colln. 40331), and the 

intercameral sutures of the final whorl are more 

nearly vertical than in the topotypes. Also, the final 

whorl in some of the Red Bird specimens is composed 

of three chambers, whereas none of the topotypes has 

a final whorl of less than 31/4 chambers. Similarities 

which suggest that the Red Bird specimens are conspecific with B. carseyae are general test shape, the 

quantum increase in chamber size within a single 

whorl, and the possession of 3i/£-4i/£ chambers in the 

early whorls. To a lesser degree, the Red Bird specimens resemble the type specimens of Bulimina reussi 

Morrow navarroensis Cushman and Parker, but they 

differ in being considerably larger and more abruptly 

enlarging than the types.

The granular nature of the test wall was noted for 

all three specimens that were crushed and examined 

under the polarizing microscope. Loeblich and Tappan 

(in Loeblich, Tappan, and others, 1964, p. C543, C545) 

stated that the walls of Buliminella and Prael>ulimina
FORAMINIFERA AT RED BIRD, WYOMING C21

are radially built. The Eed Bird specimens 

may have been recrystallized, but it is also possible that 

this character is not of the high diagnostic value 

inferred for it.

The toothplate of the Eed Bird species is much 

more like that diagrammed for Praebulimina sp. by 

Loeblich and Tappan (in Loeblich, Tappan, and 

others, 1964, p. C544, fig. 428^t) than that diagrammed for Buliminella elegantissima d'Orbigny 

(Loeblich, Tappan, and others, 1964, p. C542, fig. 

426-4a, b). Toothplates could not be observed in the 

topotypes owing to chamber fillings.

Tentative assignment is made to Buliminella carseyae based on the resemblances noted above between the 

few well-preserved Eed Bird specimens and the topotypes examined.

Occurrence and range. Applin (1933, p. 219) listed 

Buliminella carseyae from the Pierre Shale of Campanian and early Maestrichtian ages in South Dakota. 

Loranger and Gleddie (1953, fig. 3, p. 166) listed this 

species from the Bearpaw Formation of probably 

early Maestrichtian age in southwestern Saskatchewan 

and southern Alberta. Searight (1938, p. 135) listed 

this species from his (1937) Sully Member of the 

Pierre Shale of middle Campanian age in South 

Dakota. According to Cushman (1946, p. 120), B. 

carseyae is found in beds of Austin, Taylor, and 

Navarro ages in the Gulf Coastal Plain.

Genus CATICASINA Khalilov, 1951

Caucasina vitrea (Cushman and Parker)

Plate 2, figure 1

Buliminella vitrea Cushman and Parker, 1936, Cushman Lab.

Foram. Research Contr., v. 12, p. 7, pi. 2, fig. 4. 

Caucasina vitrea (Cushman and Parker). Tappan, 1962, U.S.

Geol. Survey Prof. Paper 236-C, p. 188, pi. 49, figs. 23-25. 

Mello, 1965, in Gill and Cobban, U.S. Geol. Survey Prof.

Paper 392-A, p. A13 [list]. 

Aeolostreptis vitrea (Cushman and Parker). Bergquist, 1966,

U.S. Geol. Survey Prof. Paper 302-D, p. 145, 160, 176

[lists].

Description. Test in early part composed of two 

to 2i/£ whorls consisting of six to eight low chambers 

per whorl arranged in a very low trochoid spire; 

above this early part the chambers increase more 

abruptly in size, and especially in height, as added, 

and the number per whorl abruptly decreases to 

three within about iy2 whorls; the final part is 

composed of one to two, and usually less than li/£, 

whorls of three chambers each in a bulimine arrangement. Chambers in initial low trochoid part very small 

in comparison with later chambers, increasing gradually and regularly in size as added, the two to 2^ 

whorls which they compose forming a bun-shaped 

base to the test; chambers abruptly become higher but 

increase little in width in the transitional and bulimine 

whorls, finally from iy2 to two times as high as wide 

in bulimine stage, closely appressed throughout, becoming slightly to moderately inflated in bulimine 

stage. Sutures slightly to moderately depressed inbulimine and transitional whorls, flush or very slightly 

depressed in earlier part, gently curved, oblique in 

low trochoid stage. Wall granular in microstructure, 

rather finely perforate, perforations fairly widely 

spaced. Aperture ovate to narrow and elongate, set in 

a triangular depression formed partly by the junction 

of the three final chambers and partly by an indentation of the apertural face of the final chamber, bordered on one side by a slightly protrudent, thin lip 

and on the other side by the central area of the triangular depression which is apparently filled with 

extraneous material in all specimens. Attempts at 

dissection of the final chamber to determine whether 

or not an internal toothplate is present yielded no 

information.

Dimensions. Typical specimens are approximately 

0.25 mm long and 0.13 mm in greatest width.

Remarks. The Eed Bird specimens are very closely 

similar to the holotype and especially the paratypes 

of Caucasina vitrea, and there is no doubt that they 

belong in this species.

The Eed Bird specimens are quite well preserved, 

but all appear to have a secondary filling of some kind 

in the central part of the triangular depression in 

which the aperture is set. Three specimens were partially dissected in the hope of discovering whether or 

not a toothplate was present, but the presence of 

extraneous matter within the final chambers, coupled 

with the problems in seeing such a tiny object if it 

were present, made the observations equivocal. The 

plane of coiling of the low trochoid part of the test is 

slightly to moderately oblique to the axis of elongation 

of the later part of the test in some specimens, but in 

most specimens it is perpendicular to this axis.

Occurrence and range. This distinctive species has 

been reported from the Gregory Member of the Pierre 

Shale in North Dakota (Mello, in Gill and Cobban,

1965. p. A13) and from the Schrader Bluff Formation 

of northern Alaska (Tappan, 1962, p. 188; Bergquist

1966. p. 145, 160, 176). The range of this species is 

from Santonian to Maestrichtian in the gulf coast 

(Cushman, 1946, p. 119). It occurs in Campanian age 

strata in the western interior and Alaska. At Eed Bird
C22 DESCRIPTIVE STUDY OF A CLASSIC REFERENCE LOCALITY OF THE PIERRE SHALE

the species occurs as a scarce form in two samples 

from the Red Bird Silty Member.

Genus CIBICIDES de Montfort, 1808

Cibicides sp. aff. C. beaumontianus (d'Orbigny)

Plate 2, figure 3

Truncatulina beaumontiana d'Orbigny, 1840, Soc. g4ol. France 

Mem., 1st ser., v. 4, p. 35, pi. 3, figs. 17-19.

Cibicides beaumontianus (d'Orbigny). Brotzen, 1936, Sveriges 

geol. undersokning, ser. C, no. 396, p. 188.

Description. Test trochoid, composed of as many 

as 2,1/2 whorls, spiral side planar to moderately concave, partially evolute, umbilical side subhemispherical, has a shallow, dimplelike umbilicus, involute, 

equatorial periphery slightly to moderately lobulate, 

axial periphery abruptly rounded to subacute. Chambers five to seven in final whorl, slightly to moderately 

inflated, slightly overlapping, increasing regularly and 

rather abruptly in size as added, especially parallel to 

axis of coiling; sutures moderately oblique to nearly 

radial on spiral side, slightly to moderately convex 

toward the apertural end, becoming slightly limbate 

toward the spiral suture, on umbilical side radial at 

the umbilicus, straight or slightly convex toward the 

apertural end. Wall coarsely perforate, smooth to 

somewhat roughened in texture, apparently granular 

in microstructure. Aperture a low-arched interiomarginal opening originating on the umbilical side from 

one-fourth to one-half the distance from the periphery 

to the umbilicus and continuing over the periphery 

and beneath the final chamber on the spiral side, 

bordered above by a somewhat thickened and somewhat protrudent rim, spiral side parts of the apertures, 

composed of as many as four of the preceding chambers, remain open and are separated only at the 

sutures.

Dimensions. Maximum diameter of available specimens, 0.39 mm; maximum thickness parallel to the 

axis of coiling, 0.22 mm.

Remarks. All Red Bird specimens differ from typical Cibicides beaumontianus in having a rounded 

rather than an acute axial periphery, in having five 

to seven chambers in the final whorl instead of seven 

to nine, and in failing to attain large size. In other 

respects, such as general test shape, chamber shape 

and rate of enlargement, nature of sutures and aperture, and size of perforations, the Red Bird specimens 

are very similar to typical C. beaumontianus. More 

specimens are needed before a decision can be made 

whether they represent a distinct species or simply a 

variant form of C. 'beaumontianus.

Occurrence and range. Cibicides beaumontianus 

has not previously been recorded from rocks of Campanian or Maestrichtian age in the western interior, 

Canada, or Alaska. In the Gulf Coastal Plain deposits, 

it occurs in rocks of Navarro and Taylor ages (Cushman, 1946, p. 160).

Genus DENTALINA Bisso, 1826

Dentalina basiplanata Cushman

Plate 2, figure 8

Dentalina basiplanata Cushman, 1938, Cushman Lab. Foram. 

Research Contr., v. 14, pt. 2, p. 38, pi. 6, figs. 6-8.

Description. Test uniserial, slightly arched, composed of as many as .eight chambers, slightly compressed in early part (first three or four chambers) 

except for the globular proloculus, unornamented. 

Chambers slightly compressed in the plane of curvature in the early part, later globular, increasing slowly 

in size as added, closely appressed in the early 

part, becoming progressively less closely appressed as 

added; final chamber may' be reduced in size. Sutures 

moderately oblique to the axis of elongation in early 

part, becoming more nearly perpendicular toward the 

apertural end, moderately limbate toward the concave 

side, becoming slightly limbate toward the convex 

side. Wall has radial microstructure. Aperture radial, 

at the end of a slightly produced neck, toward the 

concave side of the test.

Dimensions. For complete specimens the maximum 

length is 1.01 mm; maximum breadth, 0.17 mm; and 

maximum thickness, 0.15 mm. For incomplete specimens, maximum breadth is 0.26 mm, and maximum 

thickness is 0.25 mm.

Remarks. The illustrated specimen is apparently 

aberrant because the final chamber is reduced in size 

and has two irregular apertures. The normal radial 

and produced aperture is preserved on other specimens. The more complete Red Bird specimens correspond very closely to the type specimens of Dentalina 

basiplanata,. Assignment of the shorter partial specimens is less certain. Species of the genus Dentalina 

are often quite variable in their morphology, and in 

view of the fact that there have been no attempts at 

detailed quantification of variability for most species, 

variants of D. basiplanata may have been recorded in 

Canada, Alaska, and the western interior under different specific names.

Occurrence and range. Dentalina basiplanata has 

been reported from the Frontier Formation of inferred early Campanian age in northeastern Utah 

(Peterson, in Jones, 1953, p. 35, 36, pi. 1, figs. 22, 23),
FORAMINIFERA AT RED BIRD, WYOMING C23

from the Lea Park Formation of early Campanian 

age in south-central Saskatchewan (North and Caldwell, 1964, p. 18, pi. 3, fig. 7), and from the Schrader 

Bluff Formation of Santonian and Campanian ages in 

northern Alaska (Tappan, 1962, p. 174, 175, pi. 45, 

fig. 17; Bergquist, 1966, pi. 14). Cushman (1946, p. 68, 

pi. 24, figs. 1-6) reported it from beds of Navarro and 

Taylor ages in the Gulf Coastal Plain.

Dentalina cf. D. gracilis d'Orbigny 

Plate 2, figure 9

Dentalina gracilis d'Orbigny, 1840, Soc. ggol. France Mem., 1st 

ser., v. 4, p. 14, pi. 1, fig. 5.

Remarks. Four partial specimens are tentatively 

assigned to this species on the basis of slender and 

gently curved test shape, slightly oblique and slightly 

depressed sutures, and slightly elongate chamber 

shape. They are similar in these respects to a plesiotype of Dentalina gracilis illustrated by Cushman 

(1946, pi. 23, fig. 4).

Occurrence and range. Dentalina gracilis has been 

reported from the Gregory Member of the Pierre 

Shale of middle Campanian age in North Dakota 

(Mello, in Gill and Cobban, 1965, p. A12, A13), from 

the Campanian part of the Frontier Formation in 

northeastern Utah by Peterson (in Jones, 1953, p. 34, 

pi. 1, figs. 20, 21), from the Campanian part of the 

Hilliard Formation in southwestern Wyoming by 

Gauger (in Jones, 1953, p. 70, pi. 8, figs. 3-6), from 

the middle Campanian part of the Matanuska Formation in south-central Alaska (Bergquist, 1961, p. 2004), 

and from the late Campanian and early Maestrichtian 

part of the Pierre Shale in South Dakota by Mello 

(1969, p. 59, pi. 6, figs. lOa, b). The species is reported 

from beds of Austin, Taylor, and Navarro ages in the 

Gulf Coastal Plain deposits (Cushman, 1946, p. 65, 

66).

Dentalina legumen Reuss

Plate 2, Figure 7

Dentalina legumen Reuss, 1851, Haidinger's Naturw. Abh., v. 4, 

p. 10, pi. 1, fig. 14.

Remarks. A single well-preserved megalospheric 

specimen of this species, consisting of four chambers 

plus the bulbous proloculus, was found. The radiate 

aperture is atop a fairly short extension of the upper 

surface of the last chamber and is marginal in position. The apertural side of the test is straight, and the 

opposite side is slightly concave because of the very 

slight increase in size of the chambers as added. The 

sutures are moderately oblique and very slightly 

depressed.

Occurrence and range. Dentalina legumen has been 

reported from the early Campanian part of the Lea 

Park Formation in south-central Saskatchewan by 

North and Caldwell (1964, p. 19, pi. 3, fig. 8), with 

question from the Gregory Member of the Pierre 

Shale of middle Campanian age in North Dakota by 

Mello (in Gill and Cobban, 1965, p. A12, A13), and 

from the late Campanian and early Maestrichtian 

part of the Pierre Shale in South Dakota by Mello 

(1969, p. 60, pi. 6, fig. 11). Cushman (1946, p. 65, 

pi. 23, figs. 1, 2) reported this species from beds of 

Austin, Taylor, and Navarro ages in the Gulf Coastal 

Plain deposits.

Genus DOROTHIA Flummer, 1931

Dorothia smokyensis Wall

Plate 2, figures 10, 11

Dorothia smokyensis Wall, 1960. Research Council Alberta 

Bull. 6, p. 23-24, pi. 4, figs. 22-28.

tSpiroplectammina bentonensis Carman, 1929, Jour. Paleontology, v. 3, p. 311, pi. 34, figs. 8, 9.

Gaudryina ~bentonensis (Carman). Mello, 1969, U.S. Geol. Survey Prof. Paper 611, p. 48, pi. 4, figs, lla, b.

Description. Test elongate, straight or slightly 

arched, multiserial in earliest part, almost immediately 

becoming triserial, followed by a biserial stage in 

which the chambers show a progressive tendency 

toward uniseriality; true uniserial condition achieved 

in a small number of Red Bird specimens; early triserial part may constitute as little as one-seventh the 

length of the test in large specimens, composed of two 

or three whorls, tapering toward the initial end, generally triangular in end view but has broadly rounded 

angles, appearing oval in some specimens, sides parallel or nearly so above triserial part; early part of/ 

biserial part composed of two or three pairs of rather 

closely appressed chambers, slightly twisted, composing as little as one-third the length of most large 

specimens, later part of biserial part more loosely 

biserial, composed of as many as eight chambers, 

which become progressively less closely appressed as 

added, eventually achieving a semiuniserial condition 

in which the chambers are arranged like alternating 

wedges. Specimens attaining a true uniserial condition 

have as many as five uniserial chambers, and in these 

specimens the loose biserial part, and sometimes the 

whole biserial part, is considerably reduced although 

still present. Chambers in triserial part inflated, 

closely appressed, increasing rather abruptly in size 

as added, thus imparting a subconical appearance to 

this part of the test; chambers inflated and somewhat
C24 DESCRIPTIVE STUDY OF A CLASSIC REFERENCE LOCALITY OF THE PIERRE SHALE

less closely appressed in older part of biserial part, 

increasing very little in size as added; chambers 

inflated and even less closely appressed in younger 

part of biserial part, increasing gradually in size as 

added, and progressively approach uniseriality; in 

uniserial part chambers inflated, subglobular, moderately overlapping; transition from older closely appressed biserial part to loosely appressed biserial part 

takes place rather abruptly. Sutures in triserial part 

slightly if at all depressed, often indistinct, slightly 

to moderately depressed in early biserial part and 

deeply depressed between the more loosely arranged 

chambers of the later biserial part and in the uniserial 

part. Wall a mosaic of fine- and moderate-sized grains 

set in a moderate amount of cement, rather smoothly 

finished, moderately coarse grained and roughly 

finished in a few specimens; nearly all grains are 

quartz, but many appear to be dark because of the 

absorption of light by the dark chamber fillings; wall 

commonly collapsed when chambers not filled. Aperture in uniserial part a terminal, slightly depressed, 

rounded opening, in loosely appressed biserial part 

subterminal to terminal, in a number of specimens 

surrounded by several moderately protrudent quartz 

grains; aperture in the early biserial stage observed 

on only one specimen where it is an irregular interiomarginal arched opening along the axis of the test; 

nature of aperture in triserial part unknown because 

of absence of specimens consisting solely of this part.

Dimensions. Typical Red Bird specimens are approximately 0.75 mm long and 0.18 mm in greatest 

width; the largest specimens are about 1.63 mm long 

and 0.26 mm in greatest width.

Remarks. Most of the Red Bird specimens are 

indistinguishable from Dorothia smokyensis as described by Wall (1960, p. 23). Comparative specimens 

kindly sent to me by Wall show the loose biserial 

chamber arrangement and subterminal to terminal 

aperture characteristic of most Red Bird specimens. 

Wall reports at least four chambers per whorl in the 

early part of his species, which subsequently decrease 

to three. This character is impossible to see on most 

Red Bird specimens because of the extremely small 

size of the chambers and the rugosity of the wall, but 

perhaps also in part because of the absence of multiserial chambers in megalospheric (?) individuals. However, the multiserial arrangement is clearly present in 

some specimens.

Some of the Red Bird specimens differ from the 

type description of D. smokyensis in possessing a 

substantial uniserial part. This may represent an evolutionary advance, or gerontic development. Subspecies

should be recognized if future work shows consistent 

stratigraphic or geographic separation of the Red 

Bird and Canadian forms.

The Red Bird specimens were initially assigned 

to Spiroplectammina bentonensis Carman before the 

early part of the test was recognized to be multiserial. 

Because of compression, the type specimens of /S. 

bentonensis are very poorly preserved, and it was impossible to observe whether a multiserial part is 

present. They do show an early triserial chamber 

arrangement, followed by a closely appressed biserial 

part, and a later more loosely appressed biserial part 

as described for the Red Bird specimens. The aperture is indistinguishable on the types, but on the 

holotype the terminal part of the final chamber is 

truncated, as would be expected if the aperture were 

terminal or subterminal. This truncate appearance of 

the final chamber is well displayed by Cushman's 

(1946, pi. 7, fig. 15a) figure of the holotype. The 

tendency toward uniseriality is well displayed by a 

plesiotype illustrated by Cushman (1946, pi. 7, fig. 16) 

from the Bonham Marl of Texas. It seems likely that 

S. bentonensis and D. smokyensis are conspecific, and 

a tentative synonymization of these names is made 

here. The poor condition of the types of S. bentonensis, however, precludes the positive establishment of 

conspecificity.

Occurrence and range. Because of the commonly 

distorted or crushed nature of specimens, it seems 

likely that this species has been reported under names 

other than those recognized in this paper. Dorothia 

smokyensis was originally described from the Kaskapau and Puskwaskau Shales of Alberta by Wall (1960, 

p. 24). It has since been reported by Wall and 

Germundson (1963, p. 339-343) from beds of the 

Alberta Group ranging in age from early Coniacian 

to early Campanian and by Bergquist (1966, p. 216) 

from beds of Santonian and Campanian ages in northern Alaska. Wall (1967b, p. 81) reported it from beds 

of Turonian to Campanian ages in the Rocky Mountain foothills, and he (Wall, 1967a, p. 190) reported 

it from beds of Campanian age in the northern Rocky 

Mountain foothills. Questioned identifications of the 

species, as Gaudrywa bentonensis were made by Mello 

(in Gill and Cobban, 1965, p. A13) from the Gregory 

Member of the Pierre Shale in North Dakota and by 

Bergquist (1961, p. 2005) from the Matanuska Formation of south-central Alaska. Mello (1969, p. 48) 

reported it from the upper part of the Pierre Shale 

in South Dakota. Spiroplectammina bentonensis was 

originally reported by Carman from the Benton Shale 

near Centennial, Wyo.
FORAMINIFERA AT RED BIRD, WYOMING C25

Genus EOTTVIGERINA Cushman, 1926 

Eouvigerina sp. 1 

Plate 2, figure 2

Remarks. A single specimen, composed of five 

inflated subglobular chambers in the biserial part and 

an undetermined number of chambers in the early 

part, is given this designation. The walls are hispid 

as in Eouvigerina hispida Cushman, but the holotype 

and paratypes of this species are more slender and 

show a greater tendency toward uniseriality. Two 

arched carinae placed high 011 the sides of the final 

chamber tend to converge toward the axis of elongation of the test, as in Eouvigerina asp&ra inflata Marie 

from the Pierre Shale in north-central South Dakota 

(Mello, p. 1969, p. 74), but the absence of these carinae 

on the earlier chambers seems to set the specimen 

apart from E. aspera inflata, although it may represent an earlier evolutionary stage of this species. The 

aperture was presumably located at the end of an 

apertural neck, which has been broken off flush with 

the upper surface of the last chamber.

Genus FISSTTRINA Reuss, 1850 

Fissurina sp. A 

Plate 2, figure 6

Fissurina sp. A Perlmutter and Todd, 1965, U.S. Geol. Survey 

Prof. Paper 483-1, p. 116, pi. 3, figs. 6a, b.

Fissurina sp. A. Mello, 1969, U.S. Geol. Survey Prof. Paper 

611, p. 67, pi. 1, figs. 6, 7; pi. 7, figs. 14a, b.

Remarks. A single perfectly preserved specimen of 

this species was found. The species has been described 

from the Pierre Shale of South Dakota by Mello 

(1969) and from the Monmouth Group of New York 

by Perlmutter and Todd (1965, p. 116, pi. 3, fig. 6a, b). 

Characteristic features are the somewhat compressed, 

saclike test shape, the presence of four curved submarginal thickened areas, a small basal knob, and the 

wide slot-shaped aperture. This aperture narrows 

toward the interior into an entosolenian tube which 

extends about one-half the length of the test and ends 

in a somewhat flaring, saddle-shaped opening.

Occurrence and range. The only previous references to this species are those cited in the synonymy, 

from the Monmouth Group undifferentiated in Long 

Island, N.Y., and from the late Campanian and early 

Maestrichtian part of the Pierre Shale in South 

Dakota. The species remains unnamed for lack of 

sufficient specimens on which to base the erection of 

a new species.

Genus FRONDICULARIA Defrance, 1826

Frondicularia watersi Cushman

Plate 3, figure 7

Frondicularia watersi Cushman, 1936, Cushman Lab. Foram. 

Research Contr., v. 12, p. 14, pi. 3, figs. 14, 15.

Description. Test much compressed, consisting of 

six chambers and a megalospheric proloculus, about 

2,1/2 times as long as broad; lateral peripheries truncate, thickened but not keeled except on apertural 

neck; greatest breadth just above the base, tapering 

gradually toward the apertural end; test has a stout 

basal spine beneath the proloculus and a rather thick, 

fairly long apertural neck. Chambers chevron shaped, 

very slightly inflated, increase gradually in size as 

added, except for the arms of the chevron, which 

increase abruptly in length as added; first two chambers nearly completely embrace the proloculus, later 

chambers extend successively slightly less far back, 

but all reach back at least as far as the middle of the 

proloculus. Sutures thick, convex outward to sigmoidal, 

flush with the surface. Wall very finely perforate, moderately thick, semitransparent, unornamented, smooth 

except for random, very small flakes or chips of 

quartz (?) or calcite (?) adhering to the surface. Aperture not observed, located at the tip of the apertural 

neck, which is broken off in this specimen.

Remarks. A single well-preserved specimen of 

Frondicularia watersi was found. In test shape, chamber shape and arrangement, and presence of a basal 

spine, apertural neck, and truncate peripheries, it 

corresponds very well to the type specimens of this 

species. It differs in being megalospheric and thus 

lacks the early flabelline chamber arrangement of 

the microspheric type specimens and in being less 

strongly compressed than the types.

Occurrence and range. Frondicularia watersi has 

not previously been reported from Canada, Alaska, or 

the western interior. Cushman (1946, p. 91) reported 

it from beds of lower Navarro and Taylor ages in the 

Gulf Coastal Plain deposits and considered it to be 

characteristic of beds of Taylor age.

Genus GAUDRYINA d'Orbigny, 1839

Gaudryina watersi (Cushman)

Plate 3, figure 3

Plectina watersi Cushman, 1933, Cushman Lab. Foram. Research Contr., v. 9, pt. 3, p. 57, pi. 7, figs. la-d.

Gaudryina watersi (Cushman). Mello, 1969, U.S. Geol. Survey 

Prof. Paper 611, p. 47, pi. 4, figs. 9a-c.

Remarks. A small group of rather badly distorted 

specimens is placed in this species. Most specimens
C26 DESCRIPTIVE STUDY OF A CLASSIC REFERENCE LOCALITY OF THE PIERRE SHALE

consist only of an untwisted triserial part composed 

of as many as five whorls, but a few specimens develop 

the biserial stage. The wall is composed of numerous 

very fine grains and a scattering of larger grains set 

in considerable cement. Despite the poor preservation, 

these specimens compare sufficiently well to the type 

specimens of Plectina watersi to allow fairly confident 

assignment to this species.

Occurrence and range. Gaudryina watersi has been 

reported from the late Campanian and early Maestrichtian part of the Pierre Shale in South Dakota 

(Mello, 1969, p. 47). It has been reported by Cushman 

(1946, p. 47) from beds of Navarro age in the Gulf 

Coastal Plain.

Genus GLOBIGERINELLOIDES Cushman and ten Dam, 1948

Globigerinelloides prairieMllensis Pessagno

Plate 2, figure 5

Globigerinelloides prairieMllensis Pessagno, 1967, Palaeontographica Americana, v. 5, no. 37, p. 277, pi. 60, figs. 

2, 3; pi. 83, fig. 1; pi. 90, figs. 1-2, 4; pi. 97, figs. 3, 4.

Description. Test planispiral, slightly to moderately evolute, biumbilicate, equatorial periphery lobulate, axial periphery broadly rounded. Chambers 

globular, not closely appressed, increasing regularly 

and gradually in size as added, six or seven in the final 

whorl; final chambers in some specimens not quite 

symmetrical with regard to equatorial periphery. 

Sutures moderately to considerably depressed, straight 

and radial in side view. Wall has radial microstructure, thin, translucent, covered with fine papillae; in 

many specimens the papillae are finer on the last one 

or few chambers. Aperture interiomarginal, a moderately high-arched opening which may extend from 

one-half to nearly the full chamber height toward the 

umbilici, has a thin, short, forward-projecting lip 

above in the equatorial plane which progressively 

widens toward the umbilici into two slender flanges. 

These flanges may continue for a short distance below 

the base of the chamber as umbilically and posteriorly 

directed tonguelike projections. These extensions are 

imbricated with those of earlier chambers part way 

around the umbilicus on well-preserved specimens, but 

no relict apertures could be seen beneath them on 

any specimen.

Dimensions. Maximum diameter in the plane of 

coiling, 0.33 mm; maximum width of final chamber 

parallel to axis of coiling, 0.22 mm. Ratio of maximum 

diameter in plane of coiling to maximum diameter of 

final chamber parallel to axis of coiling is 2:1 in

small- to medium-sized specimens but decreases in 

larger specimens.

ftemarks. In discussing Biglobigerinella biforammata (Hofker) (Mello, 1969, p. 96), I stated

Nothing of a factual nature can be added here with respect 

to the controversy over the reality and the taxonomy of the 

genus Biglobigerinella. For the present the generic concept of 

Biglobigerinella is useful, even if polyphyletic, in that it encompasses forms with obvious morphologic similarities. If 

future work establishes the polyphyletic nature of the genus, 

then more subtle morphologic distinctions will have to used 

to place the species of Biglobigerinella in other genera.

Pessagno (1967, p. 274-279) has given further evidence of the polyphyletic nature of Biglobigerinella. 

However, the more subtle morphologic distinctions 

necessary for assignment of specimens have not been 

sufficiently developed by Pessagno for some species 

that he describes. The specimens I described as 

Biglobigerinella biforaminata (Hofker) (Mello, 1969, 

p. 95). fit Pessagno's description of Globigerinelloides 

multispina (Lalicker), but they do not correspond 

closely to the type specimens of G. multispina 

(Lalicker) which are much more robust, much more 

involute^ and more coarsely spinose. Pessagno has not 

adequately documented the enlargement of the definition of G. multispina which he advocated in his synonymy and discussion. The need for such documentation 

is especially acute because of the close morphologic 

similarity between G. multispina and other species of 

Globigerinelloides.

Pessagno proposed a phylogenetic lineage beginning 

with G. asperus (Ehrenberg) to G. prairiehillensis 

Pessagno to G. multispina (Lalicker). This lineage 

is characterized by an increase in rate of chamber 

enlargement, overall test size, and degree of involution 

of the test and by a decrease in apertural height. In 

addition, G. multispina develops bipartite apertures 

and paired chambers in larger specimens. The Red 

Bird specimens correspond to the type description and 

type specimens of G. prairiehillensis, except that they 

are about 10 percent smaller than the types, and they 

typically have medium- to high-arched apertures. The 

low-arched aperture described for the species is present in only a few specimens. The stage in phylogenetic 

development represented by the Red Bird specimens 

is matched in the ontogeny of the specimens I 

described from South Dakota, and given the discriminatory criteria presented by Pessagno, it is impossible 

to separate the Red Bird specimens from mediumsized South Dakota specimens. Because none of the 

Red Bird specimens develops the double aperture 

described as characteristic of G. multispina, they are
FORAMINIFERA AT RED BIRD, WYOMING C27

here placed in G. prairiehillensis. The members of this 

lineage must be more intensively studied in order to 

seek out, if possible, morphologic criteria that are 

independent of the phylogenetic development of the 

lineage, yet characteristic of the species recognized 

within the lineage.

Occurrence and range. Globigerinelloides prairiehillensis was originally reported from rocks of late 

Santonian to early Maestrichtian age in the Gulf 

Coastal Plain (Pessagno, 1967, p. 278). Specimens 

referred to Globigerina aspera or Globigerinella aspera 

and possibly conspecific with Globigerinelloides prairiehillensis have been cited eight times from rocks 

equivalent in age to the Pierre Shale in Canada and 

the western interior. Of these citations, five are in 

lists only; two (Loetterle, 1937, pi. 7, figs. 4a, b; 

Nauss, 1947, pi. 48, figs. 9a, b) do not seem to 

belong in this species; and one (North and Caldwell, 

1964, pi. 4, figs. 8a, b) may be Globigerinelloides 

prairiehillensis.

Although the specimen illustrated by Nauss (1947, 

pi. 48, figs. 9a, b) does not seem to belong in Globigerinelloides prairiehillensis, specimens from the Lea Park 

Formation probably conspecific with Nauss' concept 

of Globigerinella aspera are considered by John Wall 

(written commim., 1968) to be indistinguishable from 

Red Bird specimens here placed in Globigerinelloides 

prairiehillensis.

Genus GLOMOSPIRA Rzehak, 1888 

Glomospira charoides (Jones and Parker)

Plate 2, figure 4 

Trochammina squamata var. charoides Jones and Parker, 1860,

Geol. Soc. London Quart. Jour., v. 16, p. 304. 

Glomospira charoides (Jones and Parker). White, 1928, Jour.

Paleontology, v. 2, no. 3, p. 187, pi. 27, fig. 7. 

Mello, 1969, U.S. Geol. Survey Prof. Paper 611, p. 42, pi. 4,

figs. 4a, b.

Glomospira corona Cushman and Jarvis. Tappan, 1962, U.S. 

Geol. Survey Prof. Paper 236-C, p. 130, pi. 29, figs. 13-16. 

North and Caldwell, 1964, Saskatchewan Research Council, 

Geology Div. Kept. 5, p. 12, pi. 1, figs. 6a, b.

Remarks. Five specimens, none of which is perfectly preserved, are placed in this species. The test 

is composed of a proloculus and a tubular, undivided 

second chamber. The visible part of the test consists 

of a bell-shaped structure formed by spirals of the 

second chamber, the interior of the bell being filled, 

possibly by earlier coils and the proloculus. The 

aperture is the open end of the tube at the lower 

margin of the bell. The wall is noncalcareous and

apparently composed entirely of cement. The Red Bird 

specimens compare very well to specimens assigned to 

this species from the Pierre Shale of north-central 

South Dakota by Mello (1969, p. 42), except that the 

Red Bird specimens are somewhat more translucent.

This species has apparently been variously reported 

as Glomospira charoides, G. charoides subsp. corona 

or var. corona, and G. corona. In the original description of variety corona, Cushman and Jarvis (1928, 

p. 89) state, "Variety differing from the typical in 

having the irregularly coiled later portion in a sort 

of irregular crown at the end of the test instead of 

coiling about the whole test as in the typical form." 

Tappan (1962, p. 130, pi. 29, figs. 13-16) elevates variety corona to specific rank, but she does not illustrate 

the irregularly coiled stage nor give any additional 

morphologic criteria to discriminate G. corona from 

the "typical" G. charoides. Admittedly, the original 

description of Trochammina squamata var. charoides 

is very inadequate, and it may be that the North 

American species is to be distinguished from the 

initially described European species, but this should 

not be done without adequate documentation. For the 

lack of such documentation, G. corona is suppressed 

as a distinct species. North and Caldwell (1964, p. 12) 

report that some of the specimens that they cite as 

G. corona have a distinctive tubular cap and others 

do not. This would suggest that variety corona as 

originally defined is an advanced growth stage of G. 

charoides rather than a separate species or subspecies.

Occurrence and range. It has not been possible 

to examine the specimens cited in faunal lists as 

Glomospira charoides var. corona by Applin (1933), 

Searight (1938), and Wickenden (1945), but these 

citations are included in this discussion. Applin's 

(1933, p. 219) citation is from the Pierre Shale of 

South Dakota; Searight's (1938, p. 135) is from his 

(1937) Sully Member of the Pierre Shale of middle 

Campanian age in South Dakota and northern Nebraska; and Wickenden's (1945, p. 50) is from the 

Riding Mountain Formation of middle Campanian 

age in Manitoba and Saskatchewan. Mello (1969, 

p. 42) cited G. charoides from the late Campanian and 

possibly early Maestrichtian parts of the Pierre Shale 

in South Dakota, and North and Caldwell (1964, 

p. 12) cited G. corona from the late Santonian or 

early Campanian part of the Lea Park Formation in 

south-central Saskatchewan. Tappan's (1962, p. 130) 

citation of G. corona is from beds of Albian age in 

northern Alaska.
C28 DESCRIPTIVE STUDY OF A CLASSIC REFERENCE LOCALITY OF THE PIERRE SHALE

Genus GLOMOSPIRELLA Plummer, 1945

Glomospirella inconstans Hello, n. sp.

Plate 3, figures 1, 2

Ammodiscus cretaceus (Reuss). Mello, in Gill and Cobban, 

1965, U.S. Geol. Survey Prof. Paper 392-A, p. A12, A13 

[list].

Mello, 1969, U.S. Geol. Survey Prof. Paper 611, p. 41, pi. 4, 

fig. 3.

Description. Test moderately biconcave to planar, 

composed of a central proloculus and undivided tubular second chamber, earliest part of second chamber 

generally irregularly coiled about the proloculus but 

quickly becomes planispiral, size of the irregularly 

coiled part variable and apparently absent in a few 

specimens; in the planispiral part each whorl overlaps 

from one-fourth to one-half the height of the preceding 

whorl, two to nine whorls composing the planispiral 

part. Second chamber increases regularly and gradually 

in size with growth, has occasional constrictions of probable diagenetic origin, collapsed in many specimens. 

Wall noncalcareous, smooth to slightly roughened, 

thin and translucent in most small specimens, becomes 

thicker, opaque, and white in most larger specimens; 

some smaller specimens are thick walled, and some 

larger specimens remain thin walled; composed predominantly of cement in which numerous grains barely 

discernible at X 200 are embedded; translucent specimens appear to lack the grains. Spiral suture slightly 

depressed on undistorted specimens, more light absorbent than adjacent chamber walls and thus easily 

discernible. Aperture the open end of the second 

chamber.

Dimensions. Average-sized specimens are approximately 0.25 mm in diameter. Thickness of the test 

measured parallel to the axis of coiling is usually 

0.04 mm or less in flattened specimens but may be 

twice that in unflattened specimens of average size. 

The largest undistorted Red Bird specimen is 0.13 mm 

thick and 0.52 mm in maximum diameter. Specimens 

more than twice as large have been seen in other 

samples.

Remarks. The irregularly coiled earliest part of 

the second chamber is the character on which these 

specimens are assigned to Glomospirella. Because this 

irregular coiling involves so little of the earliest and 

smallest part of the second chamber, it can only be 

observed in the best preserved smaller specimens. In 

most larger specimens the central part of the test is 

apparently covered by secondary wall growth, and 

the irregular coiling is obscured or completely covered. 

Observation of this irregular coiling on all the smaller.

filled specimens and the regular size progression from 

smaller to larger specimens that is shown by the Red 

Bird specimens indicates that both small and large 

specimens belong in this species. A very few specimens 

that are otherwise the same as those showing the early 

irregular coiling are apparently planispiral throughout. The extremely small size of the irregularly coiled 

part might be easily overlooked, even if not obscured 

by shell overgrowth or preservation.

The presence of the irregularly coiled early part 

of the second chamber in the Red Bird specimens 

prompted a reexamination of specimens from the 

Pierre Shale of north-central South Dakota assigned 

to Ammodiscus cretaceus (Reuss) by Mello (1969, 

p. 41). Two of these South Dakota specimens clearly 

show the irregular early coiling, and in many other 

specimens there is strong indication of its existence. 

The scarcity of specimens positively having this feature is due to the scarcity in the South Dakota 

samples of small specimens having uncollapsed walls. 

Also, the irregularly coiled part is smaller and much 

more difficult to see in these specimens. Complete 

gradations in size from specimens almost as small as 

some of those at Red Bird to those considerably larger 

than any of the Red Bird specimens have been found 

in the South Dakota samples.

Specimens assigned to A. cretaceus from the Gregory Member of North Dakota (Mello, in Gill and 

Cobban, 1965, p. A12, A13) were reexamined and also 

clearly showed the early irregular coiling and other 

characteristics of G. inconstans n. sp. It seems very 

likely that this species has routinely been identified 

as A. cretaceus, but a synonymy of references cannot 

be constructed at this time because I have not yet had 

the opportunity to examine comparative specimens. 

Two small crushed paratypes of G. umbilicata (Gushman and Waters), the type species of Glomospirella, 

are very similar to G. inconstans, but most of the type 

specimens are irregularly coiled throughout, are much 

larger, and have much thicker chambers than do the 

Red Bird specimens.

There is some possibility that G. inconstans may be 

confused with Psamminopelta bowsheri Tappan, and 

especially with P. subcvrcularis Tappan, described 

from the middle Cretaceous of northern Alaska (Tappan, 1962, p. 157, 158). In P. subcircularis, the plan 

of coiling is planispiral in the later part of the test, 

and the junctures where the semicircular chambers 

meet are difficult to see.

A very similar and perhaps ancestral species to 

G. inconstans is Ammodiscus kiowensis Loeblich and 

Tappan reported from the Kiowa Shale Member of the
FORAMINIFERA AT RED BIRD, WYOMING C29

Purgatoire Formation of Kansas (Loeblich and Tappan, 1950, p. 5, pi. 1, fig. 3). This species, which should 

also be placed in Glomospirella, appears to differ 

importantly from the G. inconstans n. sp. in retaining 

irregular coiling for more of its growth. The irregular 

coiling persists throughout in the holotype, which is 

at least twice the diameter of the irregularly coiled 

part of G. inconstans n. sp. Forms transitional between 

these two species should be looked for in middle Cretaceous deposits.

Genus GYROIIUNA d'Orbigny, 1826

Gyroidina depressa (Alth)

Plate 3, figure 5

Rotalina depressa Alth, 1950, Haidinger's Naturw. Abh., v. 3, 

p. 266, pi. 13, fig. 21.

Gyroidma depressa (Alth). Cushman and Church, 1929, California Acad. Sci. Proc., 4th ser., v. 18, no. 16, p. 515, 

pi. 41, figs. 4-6.

Mello, 1969, U.S. Geol. Survey Prof. Paper 611, p. 85, pi. 10, 

figs. 2a-c.

Remarks. About a dozen specimens were found 

which are referable to this species as described by 

Mello (1969, p. 85) from the Pierre Shale of South 

Dakota. The Red Bird specimens seem to differ only 

in usually having eight chambers, instead of nine to 

11, in the final whorl, although some specimens have 

as many as 10. A discussion of the range of variation 

observed for this species, into which the Red Bird 

specimens fit, is given by Mello (1969, p. 85).

Gyroidma depressa has been reported a number of 

times from the Cretaceous interior seaway. I have 

refrained from synonymizing those references which 

appear in lists only and for which comparative material has not been seen, partly because I believe forms 

referred to this species may be more finely divisible. 

This point is discussed more fully under Gyroidina 

girardana.

Occurrence and range. Gyroidina depressa has been 

reported from the Pierre Shale undifferentiated of 

South Dakota by Applin (1933, p. 219), from the 

late Campanian and early Maestrichtian part of the 

Pierre Shale of South Dakota by Mello (1969, p. 85), 

from the middle Campanian Sully Member of the 

Pierre Shale in South Dakota and northern Nebraska 

by Searight (1938, p. 135), from the middle Campanian "chalk zone" of the Pierre Shale in South 

Dakota by Loetterle (1937, p. 42), from the middle 

Campanian Gregory Member of the Pierre Shale of 

North Dakota by Mello (in Gill and Cobban, 1966, 

p. A12, A13), from the inferred middle Campanian 

Hilliard Shale of southwestern Wyoming by Gauger

(in Jones, 1953, p. 80, pi. 9, figs. 21-26), and with 

question from the Upper Cretaceous of Manitoba and 

Saskatchewan by Wickenden (1945, p. 42).

Gyroidina girardana (Reuss) 

Plate 3, figure 6

Rotalina girardana Reuss, 1851, Deutsche geol. Gesell. Zeitschr., 

v. 3, p. 73, pi. 5, fig. 34.

Gyroidma girardana (Reuss). Cushman, 1931, Jour. Paleontology, v. 5, p. 311, pi. 36, figs. la-c.

Mello, 1969, U.S. Geol. Survey Prof. Paper 611, p. 88, pi. 10, 

figs. 3a-c.

Remarks. A few specimens, characterized by the 

planoconvex test, seven to eight chambers in the final 

whorl, and marked increase in depth of the chambers 

on the umbilical side as added, are placed in Gryoidina girardana. Comparison of these specimens was 

made with specimens of this species from the Pierre 

Shale in north-central South Dakota, and a fuller 

discussion of morphology, range, and similar species 

was given in an earlier report (Mello, 1969, p. 88). 

None of the Red Bird specimens reaches the size of 

the largest South Dakota specimens, but in other 

respects agreement is good.

Morphotypes from the western interior, Canadian, 

and Alaskan beds that have been placed in Gyroidma 

girardana, G. depressa, G. nitida, G. globosa, G. globosa orbicella, and possibly in species of Gavelinella, 

by various authors may be part of a rapidly evolving 

lineage. Slight morphologic differences have been 

found among at least the first four species listed 

above from samples of the Montana Group and older 

rocks of the western interior that I have examined. 

These differences seem to be stratigraphically separable 

and hold promise for more accurate and reliable foraminiferal biostratigraphy than is now possible for these 

rocks in the absence of planktonic species.

Occurrence and range. The only previous record 

of this species in rocks of the Montana Group and 

equivalents of the Cretaceous interior seaway north of 

the Gulf Coastal Plain was by Mello (1969, p. 88) 

from the late Campanian and possibly early Maestrichtian part of the Pierre Shale in South Dakota. 

Cushman (1946, p. 140, 141) reported it from beds of 

Austin, Taylor, and Navarro ages in the Gulf Coastal

Plain.

Gyrotidina sp. 1

Plate 3, figure 4

Description. Test low trochospiral, involute and 

moderately convex on umbilical side, partially evolute 

and slightly convex on spiral side, consisting of one to
C30 DESCRIPTIVE STUDY OF A CLASSIC REFERENCE LOCALITY OF THE PIERRE SHALE

iy2 whorls, with a large proloculus and six to eight 

chambers per whorl, axial periphery rounded, equatorial periphery smooth to slightly lobulate, has a 

shallow, dimplelike umbilicus without extensions into 

it from the chambers. Chambers closely appressed, 

slightly inflated, increasing regularly and moderately 

in size as added. Sutures moderately oblique on spiral 

side, slightly convex forward, on umbilical side radial 

at the umbilicus, straight or slightly convex forward, 

apparently slightly to moderately limbate, especially 

near the umbilicus and spiral suture, spiral suture 

indistinct, apparently limbate. Wall granular in microstructure, frosted in appearance, slightly roughened, 

rather thick, apparently secondarily thickened, especially over the central area on the spiral side, rather 

finely perforate, nearly opaque when dry, yellowish 

white. Aperture a low-arched interiomarginal slit, 

bordered above by a slight thickening of the chamber 

wall, extending from about the equatorial periphery 

toward the umbilicus for about three-quarters of the 

length of the base of the apertural face; end toward 

the umbilical side gradually tapers, spiral side ends in 

a small reentrant of the septal face.

Dimensions. This species attains a maximum diameter of 0.28 mm measured in the plane of coiling and a 

maximum thickness of 0.15 mm measured parallel to 

the axis of coiling.

Remarks. The morphology of the specimens described above does not seem to coincide in all particulars with any previously described species. However, 

because of the limited number of specimens and because 

the relationships between and the variability within 

the species of Gyroidina so far reported from the Cretaceous interior seaway are badly in need of more 

precise definition, no new name is applied to these 

specimens here. The most characteristic features of the 

specimens are the rather broadly rounded axial periphery, low and smoothly convex spiral side, not very 

deeply convex umbilical side, curved and oblique spiral 

side sutures, and frosted appearance of the wall.

Genus HAPLOPHRAGMOIDES Cushman, 1910

Haplophragmoides calcula Cushman and Waters

Plate 4, figure 7

Haplophragmoides calcula Cushman and Waters, 1927, Cushman Lab. Foram. Research Contr., v. 2, pt. 4, p. 83, fig. 5.

Remarks. A few specimens distributed at least from 

the Red Bird Silty Member to the upper unnamed shale 

member of the Pierre Shale at Red Bird compare 

favorably with the type specimens of Haplophragmoides calcula. The species, as described by Cushman 

and Waters (1927, p. 83), is characterized by close

coiling, strong compression, and a very coarsely arenaceous and roughly finished wall. The very rough wall 

texture makes internal structure indiscernible on most 

specimens, but several paratypes appear to have six 

or seven chambers in the final whorl, and the Red 

Bird specimens apparently have five to seven chambers. 

The most striking characteristics of this species are 

the extremely coarse grain size and rough wall texture. 

Angular translucent grains of quartz protrude strongly 

from the surface, and when the chambers are filled, 

these grains frequently appear dark and give the test 

a mottled appearance.

There does seem to be some gradation toward finer 

wall texture among some groups of Red Bird specimens, and H. calcula may be known by other names in 

less arenaceous environments. Cushman (1946, p. 20) 

raises the possibility that this species represents the 

young stages of Ammobaculites. However, there are 

no equally coarse-grained species of Ammobaculites in 

the Red Bird samples.

Occurrence and range. Haplophragmoides calcula 

is reported from the inferred middle and late Campanian part of the Hilliard Shale in southwestern 

Wyoming by Gauger (in Jones, 1953, p. 53, pi. 4, figs. 

7-9, 13). Cushman (1946, p. 20) reported it from beds 

of Austin, Taylor, and Navarro ages in the Gulf 

Coastal Plain.

Haplophragmoides excavata Cushman and Waters, emended

Haplophragmoides excavata Cu^hman and Waters, 1927, Cushman Lab. Foram. Research Contr., v. 2, pt. 4, p. 82, pi. 

10, figs. 3a, b.

Haplophragmoides glabra Cushman and Waters, 1927, Cushman Lab. Foram. Research Contr., v. 2, pt. 4, p. 83, pi. 

10, figs. 6a, b.

Haplophragmoides kirki Wickenden, 1932, Royal Soc. Canada

Trans., 3d ser., v. 26, sec. 4, p. 85, pi. 1, figs. la-c. 

North and Caldwell, 1964, Saskatchewan Research Council, 

Geology Div. Rept. 5, p. 13, pi. 1, fig. 8.

? Peterson, in Jones, 1953, Utah Geol. and Mineralog. Survey 

Bull. 47, p. 31, pi. 1, figs. 5a, b.

Haplophragmoides bonansaensis Stelck and Wall. Tappan, 

1962, U.S. Geol. Survey Prof. Paper 236-C, p. 133, pi. 30, 

figs. 16, 18 [not figs. 17, 19].

Mello, 1969, U.S. Geol. Survey Prof. Paper 611, p. 43, pi. 4, 

figs. 6a, b.

Description. Test planispiral, usually completely 

involute, but last three or four chambers of some 

larger specimens slightly evolute, best preserved specimens moderately robust, have slightly to moderately 

lobulate equatorial periphery and rather broadly 

rounded axial periphery, though in many specimens 

the axial periphery is narrowly rounded owing to 

inferred secondary compression. Considerable variation 

in these general characters of the test have been ob-
FORAMINIFERA AT RED BIRD, WYOMING C31

served and are interpreted as being due to distortion 

of these tests during compaction. Umbilici shallow, 

narrow to moderately wide, present on most wellpreserved specimens. Final whorl consists of as few 

as £1/2 and as many as 10 chambers, but most specimens 

have six to nine chambers; in undistorted specimens, 

chambers wedge shaped in side view, slightly inflated, 

increase regularly and gradually to fairly abruptly 

in size as added; in undistorted specimens, sutures 

straight, flush to slightly depressed, radial to slightly 

oblique, usually inconspicuous and often obscured by 

granularity of the wall, sometimes limbate. Wall 

varies from very thin in some small specimens to quite 

thick in coarser grained specimens, very variable in size 

of grains embedded in the wall, fine-grained specimens 

smoothly finished, with surface luster, coarse-grained 

specimens rough-textured, numerous specimens show 

a wide range of grain sizes; all discrete grains are 

quartz, have white cement, may be yellow or rust 

stained; wall almost always white but may be light 

or dark gray or brown when filled owing to the absorption and reflection of light by the material filling the 

test; walls of filled specimens contain a high percentage 

of seemingly dark colored grains which are really 

grains of clear quartz. Aperture a very low, equatorial, 

interiomarginal slit extending a short distance to either 

side of the periphery, commonly not preserved or 

poorly preserved.

Remarks. A very large degree of variability is 

expressed by the specimens grouped together here into 

Haplophragmoides excavata emended. This grouping 

was done only after an exhaustive observational comparison of all specimens of Haplophragmoides from 

the Ked Bird samples. The populations of specimens 

show considerable variation in grain size, degree of 

test compression, chamber shape and number, and 

degree of involution.

Such variation is probably typical of the genus and 

has, I suspect, resulted in overproduction of names, as 

it has in the case of H. excavata. It may be that the 

variations are a direct response to as yet undiscovered 

environmental controls, or perhaps they are simply 

reflective of a genetic flexibility which might suggest 

that test architecture was of less than vital importance 

to the living animal. In any event, it seems better 

to group the variants, which I believe are really more 

or less extreme variations on the same morphologic 

theme, under one name than to continue to focus on 

their differences in order to retain the established 

names. Five general morphologic end members, called 

formas, have been recognized and serve to qualify the 

morphology of specimens placed in them. These formas 

are considered to be interrelated elements of a single

species and are not of themselves valid taxonomic 

entities. The comparisons on which discussions of these 

formas are based were made with type and comparative specimens in the Cushman and U.S. National 

Museum collections. Numerous other described Cretaceous species, principally from Canada, are not considered because of the lack of comparative specimens, 

though it seems likely that several of these may be 

synonymous with H. excavata as here emended.

Haplophragmoides excavata undifferentiated

Remarks. Most of the Ked Bird specimens have 

been placed in one of the five recognized formas but, 

principally because of poor preservation, a small group 

of specimens could only be given the more general 

species designation. The samples from which these 

specimens came are listed below.

Samples and relative abundances. 21-VR, 22-R, 

24-S, 25-S?, 26-VR?, 27-S?, 31-R, 32-RR, 37-VR.

Occurrence and range. Of the four references that 

follow, two cite Haplophragmoides excavata in lists, 

and two describe and illustrate H. excavata too inadequately for confident placement in any of the formas 

recognized here. The specimens are cited here under 

H. excavata undifferentiated in order to record their 

existence. H. excavata was reported with question 

from the middle Campanian part of the Lea Park 

Shale of Alberta (Nauss, 1947, p. 331), from the middle 

Campanian part of the Pierre Shale of South Dakota 

and northern Nebraska (Searight, 1938, p. 135), and 

from the late Santonian, Campanian, and early Maestrichtian of northeastern Utah and southwestern Wyoming (Peterson, in Jones, 1953, p. 30, pi. 1, figs. 3, 4; 

Ganger, in Jones, 1953, p. 54, pi. 4, fig. 10).

Haplophragmoides excavata Cushman and Waters forma kirki 

Plate 4, figure 2

Discussion. The description and figures given by 

Wickenden (1932, p. 85, pi. 1, figs. 19-c) for Haplophragmoides kirki Wickenden, the only paratype in 

the Cushman collection (No. 19000), show that this 

species is small and involute, has the last whorl composed of four or five chambers, and has a rounded 

periphery, robust shape, and a low interiomarginal 

apertural slit.

Many specimens from the Red Bird samples fit the 

type description and compare favorably to the paratype, and many are filled like the paratype. These small 

robust specimens have four, or more commonly five, 

chambers, involute coiling, a broad periphery, and a 

low equatorial aperture grading into other forms in
C32 DESCRIPTIVE STUDY OF A CLASSIC REFERENCE LOCALITY OF THE PIERRE SHALE

the samples. There is a gradation in terms of mode of 

preservation from filled, perfectly preserved, and darkcolored specimens through incompletely filled and 

partially compressed specimens to white, flattened specimens which are otherwise similar to the filled specimens. 

Another gradation, indicated by numerous intermediate specimens, is toward greater size and increasing 

number of chambers in the final whorl. In some samples 

this dual trend leads to specimens that have robust 

test shape and fine-grained walls like the smaller 

specimens but have six or seven chambers in the final 

whorl; such specimens are included in forma alpha. 

In other samples, the average grain size increases as 

test size increases, and these specimens are included in 

forma beta. Another trend is toward specimens that 

are slightly compressed, have six to eight chambers, and 

generally fine-grained walls; such specimens are included in forma glabra. Finally, specimens that increase 

in chamber number as they increase in size and that 

are considerably compressed are considered to be transitional to forma excavata. Specimens of forma kirki 

attain a maximum diameter of 0.26 mm and a thickness, 

measured parallel to the axis of coiling in undistorted 

specimens, of 0.15 mm. Most specimens, however, are 

less than three-quarters of this size.

Samples and relative abundances. 35-VR, 44-S, 45- 

VR, 46-R, 47-VR, 48-VR, 49-VR, 51-VR, 61-VR, 

64-S, 69-S, 71-RR.

Occurrence and range. North and Caldwell (1964, 

p. 13, pi. 1, fig. 8) reported Haplophragmoides kirki, 

bearing six chambers in the final whorl, from the late 

Santonian and early Campanian part of the Lea Park 

Shale in south-central Saskatchewan. Forma kirki was 

also reported, as H. ~bonanza£n$is, by Mello (1969, p. 43) 

and at least in part by Tappan (1962, p. 133, pi. 30, 

fig. 16, 18, figured hypotypes P6005 and P6004 and 

unfigured hypotypes P6012 and P6006). Mello's report 

is from the late Campanian and early Maestrichtian 

part of the Pierre Shale in South Dakota, and Tappan's 

is from the Turonian Seabee Formation and from the 

middle Campanian part of the Schrader Bluff Formation in northern Alaska.

Other reports of H. kirki are from the inferred early 

Campanian part of the Frontier Formation in northeastern Utah (Peterson, in Jones, 1953, p. 31, pi. 1, figs. 

6a, b), from the early Campanian part of the Lea Park 

Shale of Alberta (Nauss, 194V, p. 331), and from the 

middle to late Campanian and early Maestrichtian 

Bearpaw Formation of Alberta (Loranger and Gleddie, 

1953, p. 166, fig. 3 and pi. 3, figs. 6, 7, 49, 50; Wickenden, 1932, p. 85, pi. 1, figs. la-c).

Haplophragmoides excavata Cushman and Waters forma alpha 

Plate 4, figure 1

Discussion. The group of specimens placed here 

is characterized by smoothly finished, fine-grained wall 

texture, intermediate to rather large size, involute 

planispiral coiling, six to eight chambers in the final 

whorl, commonly visible sutures, and robust test shape. 

Most specimens, and especially the larger specimens, 

are at least partially distorted. Distortion is more commonly found in forma alpha than in forma beta, presumably because the smaller grains are not so tightly 

interlocked and thus do not form so rigid a test wall 

in forma alpha. This group is artificial in the sense 

that all stages of transition between it and forma kirki 

and forma beta are to be found. The transition to 

forma beta involves an increase in average grain size 

and the resultant coarsening of the wall texture. Forma 

alpha and forma beta do not occur equally in samples 

where they occur together. Such samples contain many 

more of one forma or the other, but in some of these 

samples the transition between the two formas in 

clearly indicated.

Forma alpha attains a maximum diameter, measured in the plane of coiling, of about 0.91 mm and a 

maximum thickness, measured parallel to the axis of 

coiling on slightly distorted specimens, of about 0.37 

mm. Forma alpha is similar to the holotype and paratypes of Haplophragmoides flagleri Cushman and Hedberg var. trinitatensis Cushman and Renz, from the 

Upper Cretaceous of Trinidad, in test size and shape 

and chamber number and shape. However, the wall 

texture of var. trinitatensis, is smoother and more fine 

grained than that of forma alpha, and the umbilici, 

though not deep, are still somewhat deeper than those 

on most specimens of forma alpha.

Samples and relative abundances. 20-S?, 37-R, 

38-VR, 45-VR, 46-RR, 49-R, 50-S, 51-VR 55-VR, 

56-RR, 57-RR, 58-RR, 59-RR, 61-VR, 62-R, 63-S, 

64-S, 65-R, 66-R, 67-S, 69-S, 70-VR, 71-RR, 72-R, 

73-RR, 74-S.

Haplophragmoides excavata Cushman and Waters forma beta 

Plate 4, figure 4

Discussion. The characteristics of forma beta are 

moderate to rather coarse grain size and resultant 

rough wall texture, rather robust test shape in undistorted specimens, and six to 10 chambers in the final 

whorl, though nearly all SDecimens have seven to nine. 

Many specimens assigned here show a wide range in 

grain size, coarser grains frequently being most abundant in the umbilical regions. In specimens in which the
FORAMINIFERA AT RED BIRD, WYOMING C33

chambers are not inflated, the number of chambers is 

difficult to determine because the coarse wall texture 

obscures the sutures. Specimens considered to be transitional to forma alpha show all stages in grain-size 

increase and coarsening wall texture from the smoothtextured and fine-grained forma alpha to typical forma 

beta. Kelationship between forma beta and forma excavata also seems to be clearly indicated. Forma excavata is a secondarily, probably diagenetically compressed form having chamber walls depressed below 

the sutures, and specimens showing various stages in 

this compression from robust undistorted forma beta to 

forma excavata are available.

Large specimens of forma beta reach a maximum 

diameter, measured in the plane of coiling, of 0.90 

mm and a maximum thickness, measured parallel to 

the axis of coiling on undistorted specimens, of 0.40 

mm.

Samples and relative abundances. 19-X, 20-S?, 

23-RR?, 29-VR, 30-VR, 33-R, 34-RR, 36-VR, 37-RR, 

38-VR, 39-R, 40-R, 41-RR, 42-VR, 43-R, 44-VR, 

45-VR, 46-RR, 47-R, 48-VR, 49-R, 50-VR, 51-R, 

52-R, 53-R, 55-R, 57-RR, 58-RR, 59-RR, 60-VR, 

61-R, 62-R, 63-S, 64-X?, 65-VR?, 66-R, 67-S, 68-S, 

69-VR, 70-R, 71-VR?, 72-RR, 73-RR, T4-S, 75-X.

Haplophragmoides excavata Cushman and Waters forma excavata 

Plate 4, figure 3

Discussion. The holotype of Haplophragmoides excavata Cushman and Waters is apparently lost, and 

comparison of the Red Bird specimens was made with 

a plesiotype (Cushman colln. 26811) illustrated by 

Cushman (1946, pi. 2, fig. 15) and with other specimens of this species in the Cushman collection. The 

Red Bird specimens placed in what is here recognized 

as forma excavata are composed of seven to 10 chambers in the final whorl, the last part of which is slightly 

evolute on some larger specimens, have moderately to 

coarsely granular walls, and are characterized by 

their lenticular shape and the presence of at least a 

few depressed or excavated chambers between elevated 

sutures. All degrees of compression between the rather 

robust specimens assigned to forma beta and the lenticular and excavated specimens assigned to forma excavata are to be found in the Red Bird faunas. Forma 

excavata is considered to consist of secondarily compressed specimens of forma beta, at least some of the 

chambers of which have been depressed more deeply 

than the presumably more rigid intercameral walls. 

The scarcity of specimens of fine-grained forma excavata related to forma alpha may be due to a less 

rigid structure of the intercameral walls in these finegrained specimens. Compressed specimens of forma

alpha do exist but, at least in the specimens available, 

the chambers are only very rarely excavated. The specimens from the Cushman collection which were used 

for comparison also show varying degrees of compression and excavation and are comparable to the 

Red Bird specimens in this variability, although the 

walls of most of the Red Bird specimens contain 

coarser grains than the walls of most of the comparative specimens.

Large specimens of forma excavata attain a maximum diameter, measured in the plane of coiling, of 

about 0.75 mm. Maximum thickness parallel to the 

axis of coiling is in part a function of degree of secondary compression but is about 0.25 mm for large 

specimens.

Samples and relative abundances. 29-VR, 30-VR, 

34-RR, 36-VR, 39-R, 44-VR, 47-R, 49-R, 50-VR, 

51-VR, 52-R, 53-R, 54-RR, 55-R, 56-RK, 57-RR, 

58-R, 59-R, 60-VR, 61-VR, 65-R, 69-VR, 70-R, 

71-R, 72-R, 73-R.

Occurrence and range. The reported occurrences 

of Haplophragmoides excavata in rocks of the Montana Group and age equivalents in the Cretaceous 

interior seaway are given under the discussion of H. 

excavata undifferentiated.

Haplophragmoides excavata Cushman and Waters forma glabra 

Plate 4, figure 5

Discussion. Fifteen specimens from the Red Bird 

samples are closely comparable with the holotype of 

Haplophragmoides glabra Cushman and Waters and 

are here placed in forma glabra. They are moderately 

compressed and have an abruptly rounded axial periphery, six to eight chambers in the final whorl, smoothly 

finished walls containing fine- to medium-sized quartz 

grains, wedge-shaped chambers, and sutures which are 

radial or slightly oblique to the umbilicus and straight 

or slightly convex toward the apertural end. In terms 

of grain size, surface texture, and number of chambers, 

most of these specimens appear to be moderately 

compressed specimens of forma alpha, though a few, 

of coarser grain size, are more like forma beta. Several 

of the specimens placed in forma glabra have one or a 

few chambers slightly depressed, including the illustrated specimen (pi. 4, fig. 5), as in forma excavata. On 

the basis of these similarities, H. glabra is considered to 

be synomymous with H. excavata emended and is here 

designated as forma glabra. It is worth noting that a 

number of the specimens of H. glabra in the Cushman 

collection show transitions to forma alpha, forma beta, 

and especially to forma excavata, better than do the 

few Red Bird specimens. Of nine samples from which
C34 DESCRIPTIVE STUDY OF A CLASSIC REFERENCE LOCALITY OF THE PIERRE SHALE

Cushman (1946, p. 20) reported H. glabra, six also 

contain H. excavata (Cushman, 1946, p. 21).

Well-developed and relatively large specimens of 

forma glabra attain a maximum diameter of 0.37 mm 

and a maximum thickness of 0.18 mm.

Samples and relative abundances. 37-VR, 45-VR, 

64-X, 66-VR, 69-S.

Occurrence and range. Haplophragmoides glabra 

has been listed with question from the inferred middle 

Campanian part of the Bearpaw Formation of Alberta 

(Loranger and Gleddie, 1953, p. 166). Cushman (1946, 

p. 20) reported it from beds of Navarro age in the Gulf 

Coastal Plain.

Haplophragmoides sp. 1

Plate 4, figure 8

Remarks. Two specimens (one is poorly preserved 

and the other is well preserved except for a crushed 

final chamber) are placed under this designation. Distinguishing characteristics are the small, much compressed, almost completely evolute, planispiral or extremely low trochospiral test composed of two whorls, 

the inner of which contains nine chambers and the 

outer 12 chambers; the noncalcareous, apparently very 

finely arenaceous, smoothly finished walls; the gradual 

increase in size of the slightly inflated, closely appressed 

chambers; the well-defined, slightly depressed, slightly 

oblique, and slightly curved sutures; the subacute axial 

periphery; and the slightly lobulate equatorial periphery. The aperture could not be observed in either of 

the specimens. No previously described species of Haplophragmoides or Trochammina from the western 

interior seems to be similar to H. sp. 1.

Haplophragmoides sp. 2 

Plate 4, figure 9

Description. Test generally planispiral, partially 

evolute to involute on both sides, some specimens 

slightly asymmetrical with respect to degree of involution; some specimens apparently slightly trochospirally or slightly streptospirally coiled at least in part; 

moderately deep and moderately wide umbilici give 

the test a biconcave shape even on asymmetrical specimens; equatorial periphery slightly lobulate, axial 

periphery rather broadly rounded. Distortion of specimens not so common for this species as for specimens 

of other species of Haplophragmoides in the Red Bird 

samples. Chambers slightly inflated, in side view 

wedge-shaped in involute specimens, more keystone 

shaped in evolute specimens, seven to 10 in final whorl, 

8^-10 in medium- and large-sized specimens, increasing regularly and slowly in size as added. Sutures

slightly depressed, limbate, appearing as thin gray 

bands when specimens are moistened, straight or very 

slightly convex forward, radial or very slightly 

oblique. Wall rather thick, composed of moderately 

fine to moderately coarse particles deeply embedded 

in resinous, clear to white, glistening cement, which 

gives the walls a relatively smooth appearance; 

coarser grained walls contain numerous smaller grains, 

and finer grained walls contain scattered larger grains; 

grain size not a function of specimen size; nearly all 

grains are quartz. Apertural face low, aperture a low 

to moderately arched interiomarginal opening equatorial in position in most specimens and extending 

toward but not to the umbilici, extending more toward 

the umbilical side in specimens in which the last whorl 

is asymmetrical; filled with darker material in all 

specimens.

Dimensions. For the largest specimens, maximum 

diameter in the plane of coiling is about 0.70 mm, and 

maximum thickness parallel to the axis of coiling is 

about 0.36 mm.

Remarks. The Red Bird specimens are distinguished by the moderately deep umbilici, which may 

be partially filled, the number of chambers in the final 

whorl, the common development of a partially evolute 

final whorl, and, for most specimens, the wall of 

glistening resinous cement.

The specimens here placed in Haplophragmoides 

sp. 2 seem quite distinctive in their morphology, but 

the species has apparently not been previously described. It seems to be similar to the holotype and 

type description of H. fraseri Wickenden from the 

Upper Cretaceous Bearpaw Formation of Canada 

(Wickenden, 1932, p. 86, pi. 1, fig. 2a, b) in all respects 

except wall texture. H. fraseri is reported to have a 

wall composed of few, rather fine, angular grains and 

much cement. The color is described as white to 

yellowish. A single paratype of this species (Cushman, 1946, pi. 3, fig. 1) was available for comparison, 

but it differs markedly from the type description and 

from illustrations of the holotype, being low trochospiral and completely involute and having seven 

chambers in the final whorl. In the type description, 

the species is described as being planispiral and partially involute, and having nine or 10 chambers in the 

last whorl. Despite the similarities between H. fraseri 

as described and H. sp. 2, the marked difference 

in wall composition is considered to justify their 

separation.

The specimens assigned to H. sp. 2 are similar to 

some specimens assigned to H. excavata forma beta 

in size, test shape, and appearance of the wall, but it
FORAMINIFERA AT RED BIRD, WYOMING C35

seems possible to distinguish the specimens at hand 

consistently on the basis of the greater inflation of 

chambers and more evolute mode of coiling of H. sp. 2.

Haplophragmoides? species indeterminate

Remarks. A large number of specimens recognizable as probably belonging in the genus Haplophragmoides but too fragmentary or distorted to be 

identified to the species level are included under this 

designation. Some specimens placed here probably 

belong in Trochammina.

Genus HETEROHELIX Ehrenberg, 1843

Heterohelix globulosa (Ehrenberg)

Plate 5, figure 8

Textularia globulosa Ehrenberg, 1834, Kgl. preussische Akad,

Wiss. Berlin Abh., p. 135, pi. 4, figs. 2, 4, 5, 7, 8. 

Guembelina globulosa (Ehrenberg). Egger, 1899, Kgl. bayerische Akad. Wiss. Math.-naturw. Abt. Abh., Kl. 2,

v. 21, pt. 1, p. 32, pi. 14, fig. 43. 

Heterohelix globulosa (Ehrenberg). Montanaro-Gallitelli, 1957,

U.S. Natl. Mus. Bull. 215, p. 138, pi. 31, figs. 12-15. 

Pessagno, 1967, Palaeontographica Americana, v. 5, no. 37,

p. 260, pi. 87, figs. 5-9, 11-13. 

Mello, 1969, U.S. Geol. Survey Prof. Paper 611, p. 70, pi. 8,

figs. 5a, b.

Remarks. About 30 well-preserved specimens of 

this species were recovered from the Red Bird samples. Internal molds tentatively assigned to this species were found in several other samples. Slight 

variability was found among these specimens in 

globularity of the chambers and thickness of the test, 

but they are all considered to belong in Heterohelix 

globulosa. Very faint vertical striations are present 

on the chamber walls of a few specimens.

The small group of Red Bird specimens placed 

tentatively in H. ultimatumida (White) may represent 

an extreme in variation of H. globulosa, but the lack 

of specimens showing intermediate morphology warrants their separation at this time.

Occurrence and range. Heterohelix globulosa is a 

very widely reported species from Cretaceous rocks, 

and undoubtedly many references to it are in error 

in terms of modern classifications. This species, as 

redefined and recognized by Pessagno (1967, p. 260), 

ranges throughout strata of Campanian and Maestrichtian ages. Records of H. globulosa from the 

Cretaceous interior seaway cited below refer only to 

occurrences in beds of Campanian and Maestrichtian

Heterohelix globulosa has been reported, in recent 

years, from the late Campanian and early Maestrichtian part of the Pierre-Shale in South Dakota (Mello, 

1969, p. 70), from the Gregory Member of the Pierre 

Shale of middle Campanian age in North Dakota 

(Mello, in Gill and Cobban, 1965, p. A12, A13), and 

from the early Campanian part of the Lea Park 

Formation in south-central Saskatchewan (North and 

Caldwell, 1964, p. 21, pi. 3, figs, lla, b). As Guembelina globulosa the species has been reported from the 

Pierre Shale of South Dakota (Applin, 1933, p. 219), 

from the Sharon Springs Member of the Pierre Shale 

of early Campanian age in Colorado (LeRoy and 

Schieltz, 1958, p. 2453, fig. 1), from the early Campanian part of the Pierre Shale in South Dakota 

(Loetterle, 1937, p. 34, pi. 5, fig. 3), from the late 

Campanian part of the Bearpaw Formation in Alberta 

(Loranger and Gleddie, 1953, p. 166, fig. 3), and from 

the Boyne Member of the Vermilion River Formation, 

partly of early Campanian age, in Manitoba and 

Saskatchewan (Wickenden, 1945, p. 42).

Heterohelix pulchra (Brotzen) 

Plate 5, figure 10

Quembelina pulchra Brotzen, 1936, Sveriges geol. undersokning

Arsb., Ser. C, no. 396, v. 30, p. 121, pi. 9, figs. 3a, b. 

Guembelina pseudotessera Cushman, 1938, Cushman Lab.

Foram. Research Contr., v. 14, pt. 1, p. 14, pi. 2, figs.

19-21. 

Heterohelix pulchra (Brotzen). Montanaro-Gallitelli, 1957,

U.S. Natl. Mus. Bull. 215, p. 137, pi. 31, fig. 20. 

Mello, 1969, U.S. Geol. Survey Prof. Paper 611, p. 71, pi. 8,

figs. 4a, b.

Remarks. Two specimens are assigned to this species. They are distinguished from Heterohelix globulosa (Ehrenberg), with which they occur, in having 

lower, more elongate chambers resulting in a more 

compressed test and in having a lower arched aperture 

than is typical for H. globulosa. The last one or two 

chambers in the Red Bird specimens show a tendency 

to overlap slightly the preceding chamber on the 

opposite side of the test. Faint striations are visible 

on most of the chambers in both specimens.

Occurrence and range. Heterohelix pulchra has 

been reported from the Gregory Member of the Pierre 

Shale of middle Campanian age in North Dakota 

(Mello, in Gill and Cobban, 1965, p. A12, A13) and 

from the late Campanian and early Maestrichtian 

part of the Pierre Shale in South Dakota (Mello, 

1969, p. 71). According to Pessagno (1967, p. 262), 

this species occurs in beds of Campanian and early 

Maestrichtian ages in the Gulf Coastal Plain.
C36 DESCRIPTIVE STUDY OF A CLASSIC REFERENCE LOCALITY OF THE PIERRE SHALE

Heterohelix cf. H. ultimatumida (White) 

Plate 5, figure 9

Guembelina ultimatumida White, 1929, Jour. Paleontology, v. 3, 

no. 1, p. 39, pi. 4, figs. 13a, b.

Heterohelix ultimatumida, (White). Pessagno, 1962, Micropaleontology, v. 8, no. 3, p. 356, pi. 1, fig. 8.

Remarks. Six specimens from a single Ked Bird 

sample are tentatively placed in this species. Chambers 

are few (no more than five pairs), globular, rather 

closely appressed, and abruptly enlarging so that the 

test is nearly as broad as it is high. The aperture is 

poorly preserved on all specimens but appears to be 

a low to moderate interiomarginal arch. All specimens 

are at least partly encrusted with a thin coat of 

calcite(?), but where the wall is exposed it is smooth 

and devoid of lineations. Assignment of these specimens to Heterohelix ultimatumida, is tentative because 

of the poor preservation.

Occurrence and range. According to Pessagno 

(1967, p. 265), Heterohelix ultimatumida occurs 

throughout the Campanian and in the early Maestrichtian age deposits of the Gulf Coastal Plain. It has not 

previously been reported from the Cretaceous interior 

seaway.

Genus LAGENA Walker and Jacob, 1798

Lagena apiculata (Reuss) 

Plate 5, figure 3

Oolina apiculata Reuss, 1850, Haidinger's Naturw. Abh., v. 4,

p. 22, pi. 1, fig. 1. 

Lagena apiculata (Reuss). Reuss, 1862 (1863), Kgl. Akad.

Wiss. Wien, Math.-Naturw. Kl. Sitzungsber., v. 46, p. 319,

pi. 1, figs. 4-8. 

Mello, 1969, U.S. Geol. Survey Prof. Paper 611, p. 66, pi. 7.

fig. 11.

Remarks. Two specimens from a single sample are 

placed in this species. Each is single chambered, pyriform, and smooth walled, and each has a basal spine. 

The larger specimen has a thick, conical apertural neck 

composed of transparent shell material. The aperture 

is composed of several slits radiating from the apex 

and extending down the apertural neck for about half 

its height. A tube penetrates the axis of the apertural 

neck, but whether or not it continues into the chamber 

could not be determined because the chamber is filled. 

The apertural neck of the smaller specimen is broken. 

The Ked Bird specimens compare very closely with 

the specimen of Lagena apiculata illustrated by Mello 

(1969, pi. 7, fig. H).

Occurrence and range. Lagena apiculata has been 

reported from the middle and early Campanian part 

of the Matanuska Formation in southern Alaska

(Bergquist, 1961, p. 2004, table 1) and from the late 

Campanian and possibly early Maestrichtian part of 

the Pierre Shale in South Dakota (Mello, 1969, p. 66).

Genus LAGENAMMINA Rhumbler, 1911

Lagenammina difflugiformis (H. B. Brady)

Plate 4, figure 10

ReopJiax difflugiformis H. B. Brady, 1877, Quart. Jour. Micros.

Sci., new ser., v. 19, p. 51, pi. 4, figs. 3a, b. 

Proteonina difflugiformis (H. B. Brady). Rhumbler, 1903,

Archiv. Protistenkunde, v. 3, p. 245, text figs. 80a, b.

Description. Test a single globular to flask-shaped 

chamber, often distorted in preservation, has a neck 

attaining a length as great as that of the chamber. 

Wall composed of large, generally angular, quartz 

grains set in a white to light-brown cement which also 

contains scattered fine grains, surface very rough; most 

grains are coarse but there is variation in grain size 

within individual specimens and between specimens. 

Aperture the open end of the apertural neck.

Dimensions Average-sized specimens of this species 

are about 0.41 mm in greatest length and 0.25 mm in 

greatest breadth perpendicular to the axis of elongation. The ratio of length to breadth is usually between 

1.5:1 and 2.0:1 for complete specimens.

Remarks. According to Loeblich, Tappan, and 

others (1964, p. C216), the type species of the genus 

Proteonina, into which this frequently reported species 

has most commonly been placed, has been shown to 

belong in the genus ReopJiax. The genus Lagenammina, characterized by a coarsely arenaceous wall, 

flasklike shape, and long apertural neck, seems to accommodate the Red Bird specimens very well. L. 

diffiugiformis, originally described from the Holocene, 

is either very long ranging or the morphologic type has 

evolved several times. Specimens from the Holocene 

and Miocene in the U.S. National Museum collections 

are very similar to the Cretaceous specimens and seem 

to differ only in having a somewhat smaller average 

grain size.

Proteonina alexcmderi Loeblich and Tappan, originally described from the Kiowa Shale Member of the 

Purgatoire Formation of Kansas (Loeblich and Tappan, 1950, p. 5, pi. 1, figs. 1, 2), is very similar to the 

Red Bird specimens here assigned to L. difflugiformis, 

but the Red Bird specimens are coarser in average 

grain size and typically have a better defined apertural 

neck.

Occurrence and range. Lagenammina difflugiformis 

has been reported only once previously, under the 

generic name Proteonina^ from rocks of Campanian or 

Maestrichtian ages in the Cretaceous interior seaway.
FORAMINIFERA AT RED BIRD, WYOMING C37

The forms illustrated in the report (Gauger, in Jones, 

1953, p. 52, pi. 4, figs. 1-4) from the inferred late Campanian and early Maestrichtian part of southwestern 

Wyoming have a less well defined apertural neck than 

is typical for the Red Bird specimens.

Genus LENTICULINA Lamarck, 1804

Lenticulina muensteri (Roemer)

Plate 5, figure 1

Robulina muensteri Roemer, 1839, Versteinerungen norddeutschen Oolithengebirges, Nachtrag., p. 48, pi. 22, fig. 29.

Cristellaria muensteri (Roemer). Reuss, 1862 (1863), Kgl. 

Akad. Wiss. Wien, Math.-Naturwiss. Kl., Sitzungsber., 

v. 46, pt. 1, p. 77, pi. 9, figs. 3, 4.

Robulus muensteri (Roemer). Cushman, 1932, Jour. Paleontology, v. 6, p. 334, pi. 50, figs. 2a, b.

Lenticulina muensteri (Roemer). ten Dam, 1948, Jour. Paleontology, v. 22, no. 2, p. 178.

Remarks. ~A single specimen is placed in Lenticulina muensteri. It is distinguished by its acute, thickened periphery, small but prominent umbos, nine 

chambers in the exposed whorl, and moderately convex 

forward sutures which become raised and limbate 

toward the umbos.

The genus Robulus, to which this species has most 

frequently been ascribed, is regarded as a synonym of 

Lenticulina by Loeblich, Tappan, and others (1964, 

p. C520). Because this revision eliminates separation 

of two forms on the basis of an inconstant feature 

(length of medial apertural slit), it is accepted here, 

and this species is placed in Lenticulina.

Occurrence and range. This species has been reported, under the generic name Robulus, from the 

inferred middle Campanian part of the Hilliard Shale 

in southwestern Wyoming (Gauger, in Jones, 1953, 

p. 66, pi. 7, figs. 1, 2), with question from the early 

and middle Campanian part of the Matanuska Formation in southern Alaska (Bergquist, 1961, p. 2004), 

and from the late Campanian and early Maestrichtian 

part of the Pierre Shale in South Dakota (Mello, 1969, 

p. 53, pi. 5, figs. 6a,b).

Lenticulina cf. L. rotulata Lamarck

Lenticulina rotulata Lamarck, 1804, Annals Mus., v. 5, p. 188; 

1806, v. 8, pi. 62, fig. 110.

Remarks. A small group of specimens, which are 

varied in the degree of umbonation, curvature of the 

sutures, number of chambers, and acuteness of the 

periphery but which seem to be within the limits of 

variation for this species as illustrated by Cushman 

(1946, pi. 18, fig. 19; pi. 19, figs. 1-7), are placed with 

question in Lenticulina rotulata Lamarck. This species, 

and others from the American Cretaceous which are

referred to Lenticulina, Robulus, and Planularia, are 

in need of thorough restudy and redefinition.

Occurrence and range. Lenticulina rotulata has been 

reported from the inferred middle Campanian part of 

the Hilliard Shale in southwestern Wyoming (Gauger, 

in Jones, 1953, p. 67, pi. 7, figs. 3-5).

Genus MARGINTJLOTA d'Orbigny, 1826

Marginulina cf. M. texasensis Cushman

Plate 5, figure 2

Marginulina texana Cushman, 1937, Cushman Lab. Foram. Research Contr., v. 13, pt. 4, p. 95, pi. 14, figs. 1-4. Homonym of M. texana Garrett and Ellis, 1937.

Marginulina texasensis Cushman, 1938, Cushman Lab. Foram. 

Research Contr., v. 14, p. 95.

Remarks. A single complete specimen is tentatively 

assigned to this species. It is composed of a proloculus 

and four chambers which increase markedly in size as 

added. The first two chambers extend back nearly to 

the proloculus and form a partial coil, but the later 

chambers are uniserially arranged and extend toward 

the prolociilus on the ventral side. The dorsal margin 

is moderately convex and becomes very convex near 

the base. The ventral margin is sinusoidal; the upper 

and ventral surfaces of the final chamber form the 

convex part of the curve, and the remainder of the 

ventral margin forms the concave part. The radial 

aperture is at the apex of the test on the dorsal margin. 

In top view the test is subrounded in outline.

This specimen differs from typical Marginulina 

texasensis in having more vertically inclined chambers, 

though inclination approximating that of the Red 

Bird specimen is shown by some plesiotypes and comparative specimens of this species in the Cushman 

collection.

Occurrence and range. Marginulina texasensis has 

been reported from the inferred middle Campanian 

part of the Hilliard Shale of southwestern Wyoming 

(Gauger, in Jones, 1953, p. 69, pi. 8, fig. 2). It occurs 

in deposits of Taylor and Navarro ages in the Gulf 

Coastal Plain (Cushman, 1946, p. 61, pi. 21, figs. 21- 

29,38,40).

Genus NEOBTTLIMINA Cushman and Wickenden, 1928

Neobulimina canadensis Cushman and Wickenden-var. alpha

Plate 6, figure 1

Neobulimina canadensis Cushman and Wickenden, 1928, Cushman Lab. Foram. Research Contr., v. 4, p. 13, pi. 1, 

figs. 1, 2. 

Nauss, 1947, Jour. Paleontology, v. 21, no. 4, p. 340, pi. 48,

figs. 5a, b.

Tappan, 1962, U.S. Geol. Survey Prof. Paper 236-C, p. 185, 

pi. 48, figs. 18, 20-23, 27 [not figs. 19, 24-26].
C38 DESCRIPTIVE STUDY OF A CLASSIC REFERENCE LOCALITY OF THE PIERRE SHALE

Neobulimina canadensis Cushman and Wickenden var. alpha, 

Mello, 1969, U.S. Geol. Survey Prof. Paper 611, p. 78, 

pi, 9, figs. 5a-c.

Description. Test initially triserial, upper onequarter to one-half of larger specimens biserial, transition from triserial to biserial arrangement rather 

abrupt. Chambers subglobular, in lower one-quarter to 

two-thirds of triserial part closely appressed, arranged 

in three discrete and slightly twisted tiers, in upper onethird to one-half of triserial part less closely appressed, 

in a more bulimine arrangement, and increase more 

abruptly in size as added, one to three pairs of inflated, 

moderately appressed, slightly offset pairs of chambers 

composing the biserial part. Sutures not limbate, 

slightly depressed between closely appressed chambers 

of triserial part, becoming progressively more deeply 

incised as appression of chambers decreases. Wall 

smooth throughout, has numerous moderate-sized perforations, radial in microstructure. Aperture in the 

triserial part a vertical or nearly vertical, tightly 

arched opening, one side of which is more elevated 

than the other and the base of which is formed by the 

top of the penultimate chamber; in the biserial part, 

the aperture is a less tightly arched opening having 

one side higher than the other and the base formed by 

the top of the penultimate chamber. No toothplate visible externally in available specimens but present as an 

internal connection between apertures.

Dimensions. Average specimens are about 0.23 mm 

long and 0.12 mm in greatest width (usually in the 

biserial part). For available specimens, maximum overall length is 0.32 mm, maximum width is 0.16 mm, and 

maximum length of triserial part is 0.26 mm.

Remarks. Neobulimina canadensis var. alpha was 

introduced by Mello (1969, p. 78) as a taxonomic 

means of separating specimens of the type described 

from similar but stratigraphically higher specimens, 

called N. canadensis var. beta, from the Pierre Shale 

of north-central South Dakota. Varieties alpha and 

beta are both present in the Red Bird samples, and, 

except for one possible mutual occurrence, they are not 

found in the same samples. Var. beta is first found at 

a higher stratigraphic level than the first occurrence 

of var. alpha, but the range of var. beta is completely 

contained within that of var. alpha.

Occurrence and range. Neobulimina canadensis var. 

alpha was originally described from the late Campanian part of the Pierre Shale in north-central South 

Dakota (Mello, 1969, p. 78). Other figured specimens 

that seem referrable to var. alpha are included in Nauss 

(1947, pi. 48, figs. 5a, b) from the Lea Park Shale of 

late Santonian and early Campanian ages in Alberta 

and in Tappan (1962, pi. 48, figs. 18, 20-23, 27) from

throughout the Schrader Bluff Formation of Coniacian, 

Santonian, and Campanian ages in northern Alaska. 

Other occurrences of N. canadensis s. 1. from beds of 

Campanian age were recorded by Bergquist (1966) and 

Mello (in Gill and Cobban, 1965, p. A12, A13).

Neobulimina canadensis Cushman and Wickenden var. beta

Neobulimina canadensis Cushman and Wickenden, 1928, Cushman Lab. Foram. Research Contr., v. 4, p. 13, pi. 1, 

figs. 1, 2. 

Tappan, 1951, Cushman Lab. Foram. Research Contr., v. 2,

no. 1, p. 5, pi. 1, figs. 21a, b.

Tappan, 1962, U.S. Geol. Survey Prof. Paper 236-C, p. 185, 

pi. 48, figs. 19, 24-26 [not figs. 18, 20-23, 27].

Neobulimina canadensis Cushman and Wickenden var. beta 

Mello, 1969, U.S. Geol. Survey Prof. Paper 611, p. 79, 

pi. 9, figs. 4a-c.

Remark. A small number of specimens, all of 

which are poorly preserved, can be given this designation on the basis of comparisons made with the specimens placed in var. beta by Mello (1969, p. 71), where 

a description and illustrations of well-preserved specimens are to be found. Briefly, var. beta is characterized by a much reduced triserial stage and a long 

twisted biserial stage. The separation of Neobulimina 

canadensis into two varieties is continued here pending 

the study of specimens representing more of the geographic and stratigraphic distribution of this species.

Occurrence and range. Var. beta has previously 

been recorded from the late Campanian (?) and early 

Maestrichtian part of the Pierre Shale in north-central 

South Dakota (Mello, 1969, p. 79).

Neobulimina navarroana (Cushman)?

Virgulina navarroana Cushman, 1933, Cushman Lab. Foram.

Research Contr., v. 9, p. 63, pi. 7, figs. 9, 10. 

Neobulimina navarroana (Cushman). Mello, 1969, U.S. Geol.

Survey Prof. Paper 611, p. 80, pi. 9, figs. 3a-c. 

Neobulimina sp., Wall, 1960, Research Council Alberta Bull. 6,

p. 31, pi. 5, figs. 15-22.

Remarks. Eight specimens, all preserved as internal molds coated with limonite(?), are placed in this 

genus and species with question. The early part, in 

those specimens preserving it, is apparently composed 

of a small number of chambers in a bulimine arrangement. The later and much larger part of these specimens consists of as many as four pairs of chambers 

in a twisted biserial arrangement. The chambers in 

the biserial part are generally higher than wide and 

increase gradually in size as added. In side view the 

test is elongate and rather slender, and the early 

bulimine part tapers to a blunt point. In top view 

the test is oval.

The Red Bird specimens closely resemble the type
FORAMINIFERA AT RED BIRD, WYOMING C39

specimens of Neobulimina navarroana in those characters that are preserved, but the absence of wellpreserved apertures, features of the wall, and details 

of early chamber arrangement leave the identification 

open to question. John Wall (written commun., 1968) 

has pointed out the similarity of the Red Bird specimens to specimens described and figured by him 

(Wall, 1960, p. 31, pi. 5, figs. 15-22) as Neobulimina sp. from the Puskwaskau Shale of ConiacianSantonian age in Alberta, Canada.

Occurrence and range. Neobulimina navarroana 

has been reported from beds of early Maestrichtian 

age in north-central South Dakota (Mello, 1969, p. 80). 

It occurs in deposits of Navarro age in the Gulf 

Coastal Plain (Cushman, 1946, p. 127).

Neobulimina spinosa Cushman and Parker 

Plate 6, figure 2

Neobulimina spinosa Cushman and Parker, 1936, Cushman 

Lab. Foram. Research Contr., v. 12, p. 9, pi. 2, figs. 

lla, b.

Description. Test consists of an early part in 

which nine to 12 chambers are arranged in a twisted 

triserial to bulimine fashion, followed by a biserial 

stage consisting of one to two pairs of chambers, the 

second pair, when present, being offset from the plane 

of the first pair, greatest width of the test at about 

the base of the final chamber. Chambers in triserial 

or bulimine part globular, rather closely appressed, 

increase regularly and moderately abruptly to very 

abruptly in size as added, chambers in biserial 

part teardrop shaped, increasing regularly and rather 

slowly in size as added. Sutures slightly to moderately 

depressed in triserial or bulimine part, moderately 

depressed in biserial part. Wall radial in microstructure, on best preserved specimens transparent, has 

rather widely scattered and fairly coarse perforations, 

in a few specimens has one or a few very tiny spines 

near the bases of chambers in the triserial or bulimine 

parts, most specimens completely devoid of spines. 

Aperture in the biserial part a small, oval- to loopshaped opening within a slightly protrudent and 

compressed structure at or near the apex of the final 

chamber, paralleled by a shallow, rather narrow 

trough which also lies within the protrudent structure 

but which could not be seen to open into the chamber; 

dissection of the final chamber revealed a ridge 

mirroring the snrficial trough; on one specimen of 

three dissected there appears to be a very thin somewhat sinuous toothplate extending from the ridge to 

the trough of the penultimate chamber. The aperture 

on the triserial or bulimine chambers was not observed

because all specimens found had progressed to the 

biserial stage.

Dimensions. Average specimens are about 0.23 mm 

long and about 0.13 mm in maximum width. Large 

specimens reach a length of 0.29 mm and a maximum 

width of 0.16 mm.

Remarks. The Red Bird specimens differ from the 

type specimens of Neobulimina spinosa only in generally lacking spines. This difference is not thought 

to be important enough to consider the Red Bird 

specimens as a separate species or as a subspecies, 

especially in view of the fact that one of the paratypes 

also lacks spines. None of the types was dissected to 

determine whether the internal structures are present, 

although externally the apertures are the same as 

those in the Red Bird specimens.

Occurrence and range. Neobulimina spinosa has 

not been reported previously from deposits of Campanian or Maestrichtian age in the Cretaceous interior 

seaway. I have observed it, however, in samples from 

the Crow Creek Member of the Pierre Shale in southern South Dakota. Cushman (1946, p. 126) reported 

it from beds of Navarro and Taylor ages in the Gulf 

Coastal Plain.

Genus NODOSARIA Lamarck, 1812 

Nodosaria obscura Reuss

Plate 7, figure 10

Nodosaria obscura Reuss, 1845, Versteinerungen bohmischen 

Kreideformation, pt. 1, p. 26, pi. 13, figs. 7-9.

Remarks. Three complete specimens, two of which 

are small and composed of three and four chambers, 

respectively, are assigned to this species. The largest 

specimen consists of seven closely appressed chambers, 

the first four of which increase rather abruptly in 

width but not height as added and the last three of 

which increase rather abruptly in height but little in 

width as added. The initial end in all three specimens 

is pointed, and the walls are ornamented by as many 

as eight fairly thick, elevated costae which coalesce 

near the initial end and which extend uninterrupted 

across sutures. At the apertural end these costae join 

a low terminal ring of shell material which encloses 

the simple subrounded aperture. Several topotypes of 

Nodosaria obscura are very closely similar to the large 

Red Bird specimen, and the remaining topotypes 

differ only in having a slightly protrudent apertural 

neck.

Occurrence and range. Nodosaria obscura has not 

been reported previously from beds of Campanian or 

Maestrichtian age of the Cretaceous interior seaway. 

It occurs in beds of Austin, Taylor, and Navarro ages
C40 DESCRIPTIVE STUDY OF A CLASSIC REFERENCE LOCALITY OF THE PIERRE SHALE

in the Gulf Coastal Plain (Cushman, 1946, p. 73, 

pi. 26, figs. 15, 16).

Genus NONIONELLA Cushman, 1926 

Nonionella cf. N. taylorensis Hofker

Nonionella cretacea Oushman, 1931 [not Operculina cretacea 

Reuss, 1862], Tennessee Div. Geology Bull. 41, p. 42, 

pi. 7, fig. 2.

Nonionella taylorensis Hofker, 1955, Naturhist. Maandblad, 

Jahrg. 44, no. 9-10, p. 99.

Description. Test considerably compressed, very 

low trochospiral, involute on umbilical side, has a shallow, dimplelike umbilicus, slightly evolute on spiral 

side; equatorial periphery smooth, axial periphery 

abruptly rounded; final whorl composed of seven 

chambers. Chambers wedge shaped, slightly inflated, 

increase regularly and abruptly as added, first four in 

final whorl radially arranged to the axis of coiling, 

last three slightly oblique. Sutures straight or slightly 

convex forward, flush to slightly depressed. Wall 

smooth, unornamented, thin. Aperture an equatorial 

interiomarginal slit, presence of lateral extensions indeterminant, apertural face asymmetrical about the 

periphery, the larger lobe being on the umbilical side, 

without an extension into the umbilicus.

Remarks. Originally described as Nonionella cretacea, the species name was changed to N. taylorensis 

to remove it from homonymy with Operculina cretacea 

Reuss, which is also a species of Nonionella. A single 

pyrite-filled specimen was found. It is similar to the 

type specimens of N. taylorensis in degree of compression, size, rate of increase in chamber size, and degree 

of asymmetry of the final chamber. Nevertheless, assignment to N. taylorensis is questioned because of the 

lack of apertural details and because of the smaller 

number of chambers in the Red Bird specimen. Unfortunately, this specimen was lost during transfer for 

illustration.

Occurrence and range. Nonionella taylorensis is 

present in all members of the Schrader Bluff Formation of Senonian age in northern Alaska (Tappan, 

1962, p. 190, pi. 50, figs. 10-12; Bergquist, 1966, pi. 14). 

Cushman (1946, p. 101, pi. 43, fig. 24) reported it from 

beds of Taylor and Navarro ages in the Gulf Coastal 

Plain.

Genus OOLINA d'Orbigny, 1839

Oolina obeliscata Mello 

Plate 5, figure 4

Oolina obeliscata Mello, 1969, U.S. Geol. Survey Prof. Paper 

611, p. 66, pi. 1, figs. 5a, b; pi. 7, figs. 12, 13.

Oolina n. sp. Mello, in Gill and Cobban, 1965, U.S. Geol. Survey 

Prof. Paper 392-A, p. A12, A13.

Remarks. A single well-preserved specimen of this 

species, showing the slightly protrudent apertural neck, 

short basal spine (pyritized), internal tube, oval test 

shape, and smooth wall surface, was found. This 

species, of which the Red Bird specimen is typical, was 

first reported from the upper part of the Pierre Shale 

in north-central South Dakota by me in 1969, and a 

more complete description of it is to be found in that 

report.

Occurrence and range. Oolina obeliscata has previously been reported, as 0. n. sp, from the Gregory 

Member of the Pierre Shale of middle Campanian age 

in North Dakota (Mello, in Gill and Cobban, 1965, 

p. A12, A13). It was also reported from the late Campanian and early Maestrichtian part of the Pierre 

Shale in South Dakota (Mello, 1969, p. 66).

PSETTDOBOLIYUTA Weisner, 1931

Pseudobolivina ? sp. 1

Plate 4, figure 11

Remarks. A small group of biserial specimens, 

moderately twisted and becoming loosely biserial to 

nearly uniserial in the later part, is given this designation. The walls are smooth and composed of fine 

quartz grains rather closely set in considerable cement 

except for one specimen which contains much larger 

quartz grains and which has a roughened surface. All 

but the coarser grained specimen are distorted, and 

most specimens are incomplete. The aperture is terminal or subterminal on the chambers of the loose biserial 

part and appears to be a round opening at the end of 

a slightly produced neck. No specimens preserving the 

aperture on the early less loosely biserial part were 

found.

The biserial to nearly uniserial twisted test and the 

apparent presence of a slightly produced apertural 

neck suggest that this species is to be placed in the 

genus Pseudobolivina. Because of the poor preservation, assignment to this genus is made with question. 

The specimens could not be placed in any previously 

described species known to me.

Dimensions. The largest complete fine-grained specimen is 0.515 mm long and 0.154 mm in greatest width 

(slightly distorted). A partial specimen attains a 

maximum width of 0.195 mm (moderately distorted).

Genus PSETTDOCLAVTTLINA Cushman, 1936

Pseudoclavulina? meidamos Mello

Plate 5, figure 11

Pseudoclavulina'! meidamos Mello, 1969, U.S. Geol. Survey 

Prof. Paper 611, p. 49, pi. 1, figs. 2a-c; pi. 5, figs. la-d.
FORAMINIFERA AT RED BIRD, WYOMING C41

Remarks. A group of 10 specimens from three samples is placed in this species. Diagnostic characters are 

the presence of an early trochoid part in which the 

chambers enlarge abruptly as added, followed by a 

uniserial part in which the chambers enlarge slowly 

as added, a straight or slightly arcuate slitlike terminal aperture, very fine grain size of the wall, and small 

test size. The Ked Bird specimens differ from the type 

and comparative specimens of Pseudoclavulinal meidamos in being less well preserved, in having as many 

as six chambers in the uniserial part in contrast to a 

maximum of five in the types, and, for those specimens 

in samples 63 and 64, in being noncalcareous. PA 

meidamos was originally described as consisting 

largely, if not entirely, of agglutinated particles of 

CaCO3 held in a calcareous cement, but the noncalcareous Ked Bird specimens, which resemble this 

species in all other observable features, do not react at 

all in dilute HC1. In addition, the walls of these specimens are slightly rougher and contain slightly larger 

grains than do the types. All the Red Bird specimens 

are either incomplete or slightly to considerably 

distorted.

Occurrence and range. Pseudoclavulinat meidamos 

has so far been reported only from the late Campanian 

and early Maestrichtian part of the Pierre Shale of 

South Dakota (Mello, 1969, p. 49).

Genus REOPHAX Montfort, 1808

Reophax sp. 1 

Plate 5, figure 12

Reophax sp. A, Wall, 1960, Research Council Alberta Bull. 6,

p. 14, pi. 3, fig. 10. 

Reophax sp. 1, Wall, 1967, Research Council Alberta Bull. 20,

p. 44, pi. 5, figs. 3-5.

Description. Test uniserial, robust, nearly always 

incomplete, distorted for all specimens, consists of one 

to four chambers, slightly tapers toward initial end; 

apertural end of final chamber slightly produced on 

some specimens, forming a short, broad neck. Chambers globular, loosely appressed, generally increase 

very slowly and regularly in size as added, but in some 

specimens one or two chambers above the proloculus 

are reduced in size; proloculus large, globular, has no 

basal spine. Sutures perpendicular to axis of elongation, deeply depressed. Wall rather thick, a mosaic of 

medium- and large-sized grains, most of which are 

quartz held in a relatively small amount of cement, 

collapsed or otherwise distorted on all specimens. 

Aperture not observed on any specimen; presumably 

a simple opening at the end of the short apertural 

neck.

Dimensions. Available specimens have a maximum 

length of 1.23 mm and a maximum breadth, slightly 

crushed, of 0.57 mm.

Remarks. Specimens assigned to Reophax sp. 1 are 

distinguished from incomplete specimens of Ammobaculites coprolithiformis (Schwager) on the basis of 

the much smaller size and typically less depressed 

sutures of the latter. All chambers of specimens of 

R. sp. 1 are considerably larger than the largest chambers of A. coprolithiformis. R. sp. 1 bears a close resemblance in chamber shape and test form to R. 

constrictus (Reuss), but studied representatives of 

R. constrictus^ including a topotype, seem to have a 

less rough wall containing more cement. This same 

observation was made by Wall (1967b, p. 44) in describing his R. sp. 1. The importance of this feature 

as a distinguishing characteristic will have to await 

the finding of better preserved specimens. For the time 

being, Wall's informal nomenclature is retained.

Occurrence and range. Wall (1960, p. 14; 1967a, 

p. 44) reported this species from the upper part of the 

Kaskapau Formation in northwestern Alberta and 

from the Wapiabi and Cardium Formations of the 

Rocky Mountain foothills of Alberta. These beds range 

in age from late Turonian to middle Santonian. Reophax constrictus (Reuss) has been reported from the 

Hilliard Shale of southwestern Wyoming (Gauger, 

in Jones, 1953, p. 51) of Campanian and early Maestrichtian ages. A few partial specimens assigned to 

Gfaudryina bentonensis (Carman) by Mello (1969, p. 

48) from the upper part of the Pierre Shale in South 

Dakota probably belong in this species.

Genus RTTGOGLOBIGERINA Bronnimann, 1952 

Rugoglobigerina? sp.

Remarks. Two incomplete and poorly preserved 

specimens and one internal mold are assigned to this 

genus with question, on the basis of the globular chambers, the surfaces of which are slightly rugose, the low 

trochospiral mode of coiling that has two whorls each 

composed of five or six chambers, and the apparent 

presence of tegillae on two specimens.

Genus SACCAMMINA M. Sars, 1869 

Saccammina complanata (Franke) 

Plate 5, figures 6, 7

Pelosina complanata Franke, 1911, Kgl. preussische geol.

Landesanst. Jahrb., v. 32, pt. 2, no. 1, p. 107, pi. 3, figs.

la, b. 

Saccammina sp. 1. Wall, 1967b, Research Council Alberta Bull.

20, p. 41, pi. 14, fig. 16.
C42 DESCRIPTIVE STUDY OF A CLASSIC REFERENCE LOCALITY OF THE PIERRE SHALE

Description. Test a single chamber; nearly all 

specimens flattened and circular or subcircular in outline, probably globular in life. Wall rather thick, noncalcareous, usually smooth and composed entirely or 

almost entirely of cement, in some specimens wall consists of very fine to moderately coarse quartz grains 

embedded in much cement and has a rougher surface. 

Aperture the open end of a stout tube; tube may be 

as much as one-quarter of the diameter of the test or 

little more than a thickened apertural margin.

Dimensions. The largest specimen recovered is 

0.817 mm in length along the apertural axis and O.T43 

mm in breadth at right angles to this "axis (the specimen is completely flattened). Most specimens are onequarter to one-half of this size.

Remarks. Specimens that have walls containing 

numerous and obvious grains are few, and all intermediate stages between the coarsest and finest grained 

specimens are not represented. However, it seems 

unreasonable to split the group into several species on 

the basis of grain size when they are alike in test 

shape and apertural characters, so all are included 

here in Saccammina complanata.

Single-chambered globular specimens such as these 

could be placed in either Saccammina or Pelosina, 

according to Cushman (1948, p. 78, 81), depending 

upon whether the wall is composed of amorphous 

material (Pelosina) or is arenaceous (/Saccammina). 

Loeblich, Tappan, and others (1964, p. C196, C200) 

indicate that /Saccammina has a single opening, 

whereas Pelosina has two fine tubular extensions 180° 

apart, either or both of which may function as apertures. Because the Red Bird specimens vary in wall 

texture but are constant in having only one opening, 

the distinctions between these genera as proposed by 

Loeblich, Tappan, and others (1964) are accepted, and 

the species complanata is placed in /Saccammina.

The type figure of /S. complanata (Franke, 1911, 

pi. 3, fig. la, b) shows only a single opening, and only 

one is mentioned in the type description (Franke, 

1911, p. 107).

Occurrence and range. /Saccammina complanata 

has been reported, under the generic name Pelosma., 

from the Pierre Shale of South Dakota (Applin, 1933, 

p. 219), from the late Santonian(?) and early to 

middle Campanian parts of the Matanuska Formation 

in south-central Alaska (Bergquist, 1961, p. 2004), 

and from the middle to late Campanian part of the 

Pierre Shale in southern South Dakota (Searight, 

1938, p. 135). The specimen figured as /Saccammina 

sp. 1 by Wall (1967b, p. 41, pi. 14, fig. 16) from the

early Campanian part of the Lea Park Formation in 

Alberta is considered to belong in /S. complanata.

Genus SARACENARIA Defiance, 1824

Saracenaria triangularis (d'Orbigny)

Plate 5, figure 5

Cristellaria triangularis d'Orbigny, 1840, Soc. g6ol. France

Mem., 1st ser., v. 4, p. 27, pi. 2, figs. 21, 22. 

Saracenaria triangularis (d'Orbigny). Cushman and Church,

1929, California Acad. Sci. Proc., 4th sec., v. 18, no. 16,

p. 505, pi. 37, figs. 13, 14. 

Saraccnaria sp.(?). North and Caldwell, 1964, Saskatchewan

Research Council, Geology Div. Kept. 5, p. 18, pi. 3, figs.

2a-b, 5a-b.

Remarks. A single well-preserved specimen is assigned to this well-known species. Its exposed whorl 

consists of six chambers; they enlarge abruptly as 

added, especially in breadth and thickness, so that the 

apertural face of the last chamber is broadly triangular in shape. Another less well preserved and smaller 

specimen from the same sample is assigned to this 

species with question.

Occurrence and range. Saracenaria triangularis has 

been reported from the early and middle Campanian 

parts of the Matanuska Formation of south-central 

Alaska (Bergquist, 1961, p. 2004). Cushman (1946, 

p. 58) reported it from beds of Austin, Taylor, and 

Navarro ages in the Gulf Coastal Plain.

/Saracenaria sp., described and illustrated by North 

and Caldwell (1964, p. 18, pi. 3, figs. 2a-b, 5a-b) and 

probably referrable to /S. triangularis, occurs in the 

upper part of the Lea Park Formation of early Campanian age in southern Saskatchewan.

Genus SILICOSIGMOILINA Cushman and Church, 1929

Silicosigmoilina futabaensis Asano

Plate 6, figure 5

Silicosiffmoilina futabaensis Asano, 1950, Pacific Sci., v. 4,

no. 2, p. 159, pi. 1, figs. 6, 7. 

Mello, 1969, U.S. Geol. Survey Prof. Paper 611, p. 51, pi. 5,

figs. 3a, b. 

Silicosigmoilina californica Cushman and Church. Applin, 1933,

Jour. Paleontology, v. 7, no. 2, p. 219 [not Cushman and

Church, 1929].

Description. Test considerably compressed, generally oval in outline, but a few specimens nearly 

circular and many specimens fusiform in outline; 

early part indistinct, but chambers composing it obviously not in the plane of the later chambers; the 

addition of later chambers in planes about 180° apart 

gives the test its compressed appearance; margins 

abruptly rounded to subacute. Chambers in early part
FORAMINIFERA AT RED BIRD, WYOMING C43

indistinct, small, fairly numerous; in later planispiral 

or nearly planispiral part, very elongate, convex outward to sigmoidal, slightly overlapping; thin in small 

specimens, becoming increasingly broad and more 

overlapping in larger specimens. Wall noncalcareous, 

composed of numerous very fine grains in much 

cement, white, opaque, collapsed in many chambers. 

Sutures indistinct, visible only when moistened, if at 

all, flush with the surface. Aperture the open end of 

the final chamber, rounded or subrounded, has no 

discernible apertural tooth, closed or distorted by 

compression in most specimens.

Dimensions. Available specimens attain a maximum length of 0.72 mm and a maximum breadth of 

0.40 mm. Maximum thickness of uncompressed chambers reaches 0.11 mm. Most specimens are considerably 

narrower than the 7:4 length-to-breadth ratio would 

indicate.

Remarks. The Red Bird specimens are identical 

with specimens from the Pierre Shale of north-central 

South Dakota assigned to this species by Mello (1969, 

p. 51), except that more of the Red Bird specimens 

are elongate or fusiform and fewer are subrounded in 

outline.

The type species of the genus Silicosigmoilina is 

S. calif omica Cushman and Church. In the original 

description, the early chambers are described as being 

planispiral or nearly so, that is, arranged in a single 

plane (Cushman and Church, 1929, p. 502), but one 

of their type figures (pi. 36, fig. 12), a cross-sectional 

view, shows no such early arrangement. Paratypes in 

the Cushman collection also show no planar early part 

(the holotype and figured paratypes are housed in the 

Museum of the California Academy of Sciences and 

were not examined in this study). The uncertainty 

about the nature of coiling in this genus raises serious 

question as to its true nature and possible validity. A 

decision on these points will have to be made based on 

all the type specimens, especially the holotype.

Of more distinct pertinence to this study, one of 

the smaller paratypes of S. californica (Cushman 

colln. 14496) has its later chambers arranged nearly 

in a plane, unlike the less planar, more overlapping 

sigmoidal arrangement in the other paratypes, and is 

very closely similar to the Red Bird specimens. This 

paratype may represent a stage of development 

immediately preceding the growth of larger more 

enveloping chambers which depart from the planar 

arrangement to form the more sigmoidal test shape. 

The Red Bird specimens may represent an earlier 

ontogenetic stage or a different level of evolutionary 

advancement than is shown by the paratypes of S.

californica. Efforts to examine chamber arrangement 

in cross section of the Red Bird specimens were not 

successful owing to chamber fillings of the same color 

and consistency as the walls (possibly originally 

deposited by the living animal).

In summary, the status of the genus Silicosigmoilina 

is not clear because of the uncertainty raised here 

concerning the arrangement of its early chambers. 

Also, a paratype of S. californica, the type species of 

the genus, is very similar to the Red Bird specimens 

and suggests a close ontogenetic or evolutionary relationship. The Red Bird specimens are placed in 

S. futdbaensis because the description and figures of 

this species seem to encompass them, at least in most 

respects. Both the genus Silicosigmoilina and its type 

species need redescription and more precise definition.

Occurrence and range. Silicosigmoilina futdba&nsis 

has previously been described from the late Campanian part of the Pierre Shale in South Dakota 

(Mello, 1969, p. 51). Four authors have listed S. californica Cushman and Church from Cretaceous interior 

seaway deposits. Mello (1969) synonymized S. californica of Applin (1933, p. 219) from the Pierre Shale 

of South Dakota with S. futdbaensis. In the absence 

of descriptions and illustrations, it is impossible to 

determine whether the following citations of S. californica might belong in S. futdbaensis: Wickenden 

(1945, p. 50), from the Riding Mountain Formation 

of Manitoba and Saskatchewan; Bergquist (1961, 

p. 2004), from the Matanuska Formation of southcentral Alaska; Searight (1938, p. 135), from the 

Pierre Shale of southern South Dakota and northern 

Nebraska.

Genus SPIROPLECTAJOUNA Cushman, 1927

Spiroplectammina sp. 1 

Plate 6, figures 3, 4; text figure 4

Description. Test planispiral in earliest part; most 

of the test biserial, moderately compressed, tapers 

toward the planispiral part; rate of increase in width 

with growth variable from specimen to specimen, in 

most larger specimens rate of increase in width 

decreases in later part; lateral peripheries moderately 

to rather abruptly rounded, smooth to slightly lobulate; 

in many specimens left and right sides of the test 

meet in a low angle along the midline of the test, in 

other specimens the central area is smoothly arched 

instead of angled. Chambers in planispiral part very 

small, obscure, generally four to five visible, constituting the lower one-half of the planispiral part, the 

remainder generally being overlapped by the biserial
C44 DESCRIPTIVE STUDY OF A CLASSIC REFERENCE LOCALITY OF THE PIERRE SHALE

part; chambers in the biserial part slightly or not at 

all inflated, overlapping about the upper one-third of 

the underlying chamber, narrowest at lateral peripheries, broadest at the midline, arranged at 45°-80°, 

to the midline. Sutures flush to slightly depressed, 

straight or slightly convex upward. Wall moderately 

thick, rather smoothly finished, composed of numerous 

angular and rounded quartz grains set in a white to 

whitish-yellow cement; cement completely soluble in 

dilute HC1 in some specimens, insoluble in others. 

Aperture a low-arched interiomarginal slit, forms 

about one-third of the base of the low apertural face, 

flanked by two slight extensions of the apertural face 

toward the penultimate chamber.

Dimensions. Average sized specimens are about 

0.40 mm long, 0.28 mm broad, and 048 mm thick. An 

idea of the range of variation in these dimensions can 

be obtained from the outline drawings in figure 4.

Remarks. This species varies in width of the test, 

angularity of the midline, angularity of the lateral 

peripheries, and nature of the wall cement. Treatment 

of about 40 specimens from five samples with acid 

showed that soluble- and insoluble-walled specimens 

sometimes occur in the same sample. Of about 25 

tested specimens from three samples containing no 

calcareous Foraminifera other than internal molds, 

only one specimen had a soluble wall. In the other two 

samples, which do contain calcareous Foraminifera, 

both soluble and insoluble specimens were found. In 

all other respects, aside from wall solubility, the 

soluble- and insoluble-walled specimens are alike. 

Color of the wall is not correlated with its solubility.

The Red Bird specimens most closely approximate 

Spiroplectammina semicomplanata (Carsey) from the 

gulf coast Cretaceous deposits. However, the coarser 

grain size, greater chamber size, greater overall size,

a d

FIGURE 4. Outline drawings of Spiroplectammina sp. 1 and of a topotype of 8. semicomplanata (Carsey). In each pair of drawings, the figure on the 

left is an apertural view and on the right, a side view, a, Topotype of Spiroplectammina semicomplanata (Carsey), X 106, Cushman colln. 26965. 

\t-g, Spiroplectammina sp. 1, X 106: 6, USNM 68901; c, USNM 68902; d, USNM 68903; e, USNM 68904; /, USNM 68906; g, USNM 68905.
FORAMINIFERA AT RED BIRD, WYOMING C45

less compressed test, and flush or only slightly elevated 

sutures of the Ked Bird specimens distinguish them 

from topotypes of S. semicomplanata. Some of the 

Red Bird specimens approximate Spiroplectammina 

mordenensis Wickenden in having narrower tests and 

rather rounded lateral peripheries but differ in having 

lower chambers and much smaller planispiral parts. 

Comparison of the Red Bird specimens with type specimens and comparative specimens of numerous other 

Cretaceous species of Spiroplectammina, and examination of the Cretaceous literature, did not reveal a 

species to which the specimens could confidently be 

assigned. The Red Bird specimens seem to represent 

a previously undescribed species, but they are not 

given formal status as a new species here because, in 

my opinion, the Cretaceous representatives of Spvroplectammina have been oversplit, and a reexamination 

of variation in some of the established species may 

show that the Red Bird specimens belong in one of 

them.

Genus STILOSTOMELLA Chippy, 1894

Stilostomella sp. 1 

Plate 7, figures 1-3

Description. Test calcareous, rectilinear, consists 

of as many as nine chambers, tapers slowly toward 

the globular proloculus, has a short basal spine which 

is broken off on most specimens. Chambers moderately 

inflated, in early part wider than high and slightly 

to moderately overlapping, progressively becoming 

higher than wide and less overlapping so that the 

final few chambers overlap very slightly and are as 

high as wide or as much as 1^ times as high as 

wide. Sutures slightly depressed in early part, becoming progressively more depressed between succeeding chambers and rather deeply depressed between 

final few chambers of largest specimens, perpendicular 

to the axis of elongation. Wall thin, apparently a 

single layer, apparently nonperforate, granular in 

microstmcture, surface roughened, has very faint, 

discontinuous vertical lineations, small spines sometimes present just above the boundary with the underlying chamber. Aperture situated at the top of a very 

short apertural neck, consists of a subrounded opening, 

bordered by a smooth, slightly thickened lip, some 

specimens having a relatively large indentation of the 

lip into the aperture, inner area of lip irregular to 

somewhat dentate.

Dimensions. The only two unfigured specimens 

retaining the proloculus are, respectively, 0.44 mm 

long and 0.08 mm wide, and 0.23 mm long and 0.06 mm 

wide.

Remarks. The granular wall structure and absence 

of perforations are interpreted to be due to recrystallization, and the eight Red Bird specimens upon which 

the description is based are placed in the genus 

Stilostomella. S. pseudoscripta (Cushman) and 8. 

alexanderi (Cushman) are the only species of Stilostomella previously reported from Campanian or Maestrichtian rocks of the Cretaceous interior seaway. The 

Red Bird specimens are smaller, much less spinose, and 

much less constricted at the sutures than the types of 

S. alexanderi. Although the Red Bird specimens are 

similar in size to the types of S. pseudoscripta, they 

differ in lacking the distinctive pyriform chamber 

shape and numerous fine spines which are downward 

directed at the lower margins of the chambers. The 

Red Bird specimens have not been given a specific 

name, pending wider study of rocks from the Cretaceous interior seaway. As far as can be determined from 

the figures, the specimens illustrated by North and 

Caldwell (1964, pi. 4, figs. 2, 3) as Stilostomella 

pseudoscripta from the Lea Park Formation of southern Saskatchewan are closely similar to the Red Bird 

specimens in terms of chamber shape, occasional presence of scarce spines, and overall test shape. North and 

Caldwell's specimens are about 0.65 mm long and 0.12 

mm wide.

Genus TEXTTTLARIA Defiance, 1824 

Textularia sp. 1 

Plate 7, figure 5

Textularia inflata Gauger?, [not Textularia inflata Ehrenberg, 

1854, Mikrogeologie, pi. 30, fig. 12], in Jones, 1953, Utah 

Geol. and Mineralog. Survey Bull. 47, p. 60, pi. 6, figs. 

12-14.

Description. Test noncalcareous, biserial, elongate, 

tapers gradually from a very narrow, rounded initial 

end to the greatest breadth and width at the last pair 

of chambers; lateral peripheries slightly to moderately 

lobulate; outline in apertural view oval. Chambers 

inflated, subglobular, closely appressed, increase regularly in size as added, sutures slightly to moderately 

depressed, not limbate, generally at 90° angles to the 

axis of elongation but occasionally slightly less than 

90°. Wall almost always white, translucent except 

when chambers are filled, has very few silt or sand 

grains visible at X 200, much silicious( ?) cement; apparently originally somewhat flexible judging from 

the large proportion of flattened or distorted specimens, slightly roughened in texture on undeformed 

specimens. Aperture destroyed or covered on all but 

one specimen on which it is a small, low-arched open-
C46 DESCRIPTIVE STUDY OF A CLASSIC REFERENCE LOCALITY OF THE PIERRE SHALE

ing at the base of the low apertural face of the final 

chamber.

Dimensions. Average specimens are about 0.25 mm 

long, 0.08 mm in maximum breadth, and 0.05 mm in 

maximum thickness. The largest specimen (crushed) 

is 0.44 mm long.

Remarks. The Pierre specimens are distinguished 

by the inflated, subglobular chambers (when uncrushed) and by the typically white and translucent 

wall. The brief original description and poor type 

figures of Textularia inflata Gauger make the assignment of the Pierre specimens to this species doubtful. 

Points of similarity are the elongate and narrow test 

and the presence of inflated apparently subglobular 

chambers.

Although Textularia inflata Gauger is a homonym, 

no new name is proposed here because I have not seen 

the type specimens. On the basis of the inadequate 

description and figures, the Red Bird specimens seem 

to be identical with Gauger's specimens from Wyoming. An apparently similar but also poorly illustrated 

species is Textularia, gravenori Stelck and Wall from 

the Cenomanian of Alberta (Stelck and Wall, 1955, 

p. 55, pi. 2, fig. 36).

The Ked Bird specimens resemble Textularia topagorukensis Tappan (Tappan, 1957, p. 205, pi. 66, figs. 

8, 9) in chamber shape, test shape, wall texture, and 

suture angle, but T. topagorukensis has larger and 

fewer chambers, is larger in size and more robust, has 

more silt grains embedded in the walls, and is distinct 

from the Red Bird species.

Occurrence and range. Textularia inflata Gauger 

was reported from the inferred middle Campanian 

part of the Milliard Shale of southwest Wyoming 

(Gauger, in Jones, 1953, p. 60, pi. 6, figs. 12-14).

Genus TROCHAMMINA Parker and Jones, 1859

Trochammina diagonis (Carsey)

Plate 6, figure 7

Haplophragmoides diagonis Carsey, 1926, Texas Univ. Bull.

2612, p. 22, pi. 3, fig. 1.

Trochammina diagonis (Carsey). Cushman and Waters, 1927, 

Cushman Lab. Foram. Research Contr., v. 2, pt. 4, p. 84, 

pi. 10, figs. 7a, c.

?. Gauger, in Jones, 1953, Utah Gteol. and Mineralog. Survey Bull. 47, p. 64, pi. 6, fig. 20. 

Tappan, 1962, U.S. Geol. Survey Prof. Paper 236-C, p. 153,

pi. 38, figs. 1-4.

North and Caldwell, 1964, Saskatchewan Research Council, 

Geology Div. Rept. 5, p. 16, pi. 2, figs. 7a-c.

Description. Test low trochospiral, possibly streptospiral in earliest part, most specimens of 1% to two 

whorls, usually completely involute on spiral side but

occasionally slightly evolute, test becomes moderately 

evolute in the few very large specimens, umbilical side 

moderately convex but has a central umbilicus which 

is narrow and deep on larger undistorted specimens, 

shallower and proportionately broader on smaller 

specimens, spiral side generally slightly to moderately 

convex but planar or slightly concave on some specimens, equatorial periphery slightly to moderately 

lobulate, axial periphery narrowly rounded in smaller 

specimens, gradually becomes more broadly rounded 

as size increases, abrupt in some specimens inferred to 

be distorted. Chambers inflated, six to eight in final 

whorl of most specimens, but as many as 11 in some of 

the largest specimens, enlarge regularly and fairly 

abruptly in size as added; in either spiral- or 

umbilical-side view, most chambers shaped like blunt, 

bulging wedges, but some are sharply wedge shaped 

and others show little taper at all from periphery to 

inner margin. Sutures slightly to moderately depressed, straight in side views, radial on umbilical side, 

radial to moderately oblique on spiral side. Wall thin 

and finely arenaceous in smallest specimens, becomes 

thicker and increases in average grain size as specimen 

size increases; however, even the largest specimens are 

not exceptionally coarse grained; all but the largest 

grains are deeply embedded in cement, and thus the 

wall has a rather smooth surface texture; nearly all 

grains are quartz. Aperture observed on only two large 

specimens, in which it is a low interiomarginal opening extending from about one-half the height of the 

first chamber of the final whorl into the umbilicus and 

thence beneath the umbilical margin of the final 

chamber.

Dimensions. A few specimens attain a maximum 

diameter of 1.0 mm (crushed), but average-size specimens are approximately 0.35 mm in greatest diameter 

and 0.27 mm in least diameter measured in the plane 

of coiling through the center of the test (crushed 

specimens).

Remarks. Comparison has been made with a topotype of Trochammina diagonis (Cushman colln. 

40314). There is a remarkable similarity in wall texture, color, and grain size between this specimen and 

the plesiotype illustrated here, as well as many of the 

other larger Pierre specimens. The topotype is slightly 

larger than the plesiotype and more distorted, but, for 

specimens that lack sharply distinctive morphologic 

features, agreement is very good. Smaller specimens 

assigned to this species are not so closely comparable 

with the topotype in that they have much smaller 

chambers, thinner walls, and finer grain size. These 

specimens are included in T. diagonis, sometimes with
FORAMINIFERA AT RED BIRD, WYOMING C47

question, on the basis of their trochospirality, frequent 

association with larger specimens assignable to the 

species, and because in a few samples suites of specimens transitional from the smaller to the larger specimens indicate that they are to be placed together.

Virtually every Red Bird specimen assigned to this 

species is distorted, as are most of the plesiotypes and 

comparative specimens in the Cushman collection. 

Consequently the assignment of specimens to this 

species is more subjective than for most species.

Occurrence and range. Trochammina diagonis 

(Carsey) has been reported from the inferred middle 

and late Campanian parts of the Hilliard Shale of 

southwest Wyoming (Gauger, in Jones, 1953, p. 64, 

pi. 6, fig. 20), from the lower part of the Lea Park 

Formation of late Santonian age in south-central Saskatchewan (North and Caldwell, 1964, p. 16, pi. 2, 

figs. 7a-c), and from the upper two-thirds of the 

Schrader Bluff Formation of late Santonian and Campanian ages in northern Alaska (Tappan, 1962, p. 153. 

pi. 38, figs. 1-4; Bergquist, 1966, pi. 14).

Trochammina globosa Bolin 

Plate 6, figure 8

Trochammina globosa Bolin, 1956, Jour. Paleontology, v. 30,

no. 2, p. 289, pi. 38, figs. 8, 9; text figs. 5, 7. 

Mello, 1969, U.S. Geol. Survey Prof. Paper 611, p. 52, pi. 5,

figs. 5a-c.

Description. Test trochospiral, involute on umbilical side, evolute on spiral side, spiral side low convex, 

umbilical side concave, has a broad, shallow umbilicus, 

available specimens of two whorls or less, final whorl 

consists of five to seven chambers, axial periphery 

rather abruptly rounded, equatorial outline roughly 

ovate, equatorial periphery slightly lobulate. Chambers 

increase regularly and rather abruptly in size as 

added; subequant, often somewhat arched in spiralside view; in umbilical-side view wedge shaped because 

of the extension into the umbilicus, often somewhat 

arched, slightly to moderately compressed parallel to 

the axis of coiling. Sutures in spiral and umbilical side 

views straight to moderately convex toward the apertural end, sometimes radial but more commonly 

slightly to moderately oblique to the axis of coiling, 

indistinct because of coarse grain size. Wall rough 

textured, thick, composed of a large proportion of 

relatively coarse grains, nearly all of which are quartz, 

set in a flat-white to yellowish-white cement; very few 

small grains are present except proportionately more 

on smaller specimens, especially on the umbilical sides. 

Dimensions. Average size specimens are approximately 0.36 mm in maximum diameter and 0.29 mm in

minimum diameter, measured across the spiral side 

through the center of the test, and are approximately 

0.18 mm in height, measured parallel to the spiral axis.

Remarks. Characteristic features of this species are 

the generally wide, shallow umbilicus, low-spired 

convexo-concave shape, the ovate outline resulting 

from the fairly abrupt chamber enlargement coupled 

with the evolute nature of the spiral side, the compressed and frequently arcuate chamber shape, and the 

usual abundance of coarse grains in the wall.

The Red Bird specimens are more compressed than 

is indicated in the type description and figures of 

Trochammina globosa Bolin, and if this compression 

is a primary character not related to preservational 

distortion, it might warrant their separation as a new 

species. The Red Bird specimens are closely similar to 

specimens of T. globosa reported from the Pierre Shale 

of South Dakota (Mello, 1969, p. 52).

Occurrence and range. Trochammina globosa has 

been reported only twice previously from the early 

Maestrichtian part of the Pierre Shale in South 

Dakota (Mello, 1969, p. 52), and from well cores in 

Minnesota, very tentatively dated as Cenomanian 

(Bolin, 1956, p. 289).

Trochammina ribstonensis Wickenden 

Plate 6, figure 6

Trochammina ribstonensis Wickenden, 1932, Royal Soc. Canada

Trans., 3d ser., v. 26, sec. 4, p. 90, pi. 1, figs 12a-c. 

Nauss, 1947, Jour. Paleontology, v. 21, no. 4, p. 340, pi. 49,

figs. 6a-c. 

Tappan, 1962 [part], U.S. Geol. Survey Prof. Paper 236-C,

p. 154-155, pi. 39, figs. 16, 17 [not figs. 15a-c]. 

Wall, 1967b, Research Council Alberta Bull. 20, p. 67, pi.

10, figs. 20-25.

Description. Test low trochospiral, most specimens 

having ll/2-^l/2 whorls and six to &i/2 chambers per 

whorl, equatorial periphery lobulate, axial periphery 

rounded, has a broad, moderately deep umbilicus. 

Chambers moderately inflated, rather closely appressed, increasing gradually and regularly in size as 

added. Sutures slightly depressed between early chambers, moderately depressed between last four or five 

chambers, slightly to moderately oblique on spiral side, 

slightly oblique to radial on umbilical side, convex 

toward the apertural end, spiral suture distinct, depressed, having a scalloped pattern. Wall noncalcareous, thin, translucent, white, appears granular but 

has very few clearly distinguishable enclosed grains, 

apparently flexible in life, judging from the large 

proportion of distorted specimens, surface texture 

smooth. Aperture observed on only one specimen
C48 DESCRIPTIVE STUDY OF A CLASSIC REFERENCE LOCALITY OF THE PIERRE SHALE

where it is an interiomarginal slit on the umbilical 

side extending from the periphery to about two-thirds 

the distance to the umbilicus.

Dimensions. Average-size specimens have a maximum diameter, in the plane of coiling, of about 

0.17 mm, a minimum diameter of about 0.13 mm, and 

a thickness parallel to the axis of coiling of about 

0.05 mm. Larger, crushed specimens attain a maximum 

diameter of 0.28 mm.

Remarks. The most distinctive characters of this 

species are the number of chambers, low spire, obliquity of the sutures, smoothness of the wall, and very 

fine grain size. The Red Bird specimens are very 

closely similar to examined paratypes of Trochammina 

ribstonensis Wickenden, except that the paratypes are 

filled, and thus the walls are darker in color.

The hypotype illustrated by Tappan (1962, pi. 39, 

figs. 15a-c) is almost certainly not this species; I am 

following WalFs (1967b, p. 67) example and excluding 

it from the synonymy.

Occurrence and range. Trochammina ribstonensis 

is a distinctive species and has been widely reported 

from the Cretaceous of Canada and Alaska. It was 

originally described from a borehole in Alberta, probably from the Lea Park Formation, by Wickenden 

(1932, p. 90, pi. 1, figs. 12a-c). Since then, it has been 

reported in Canada from the lower 40 feet of the Lea 

Park Shale of late Santonian age in Alberta (Nauss, 

1947, p. 340, pi. 49, figs. 6a-c), from the lower part of 

the Lea Park Formation near Lloydminster, Saskatchewan (Wickenden, 1941), from the Bearpaw 

Formation of middle and late Campanian and early 

Maestrichtian ages in southwestern Saskatchewan and 

southern Alberta (Loranger and Gleddie, 1953, p. 166, 

fig. 3), and from the early Campanian part of the 

Wapiabi Formation in the Rocky Mountain foothills 

of Canada (Wall and Germundson, 1963, p. 343; Wall, 

1967a, p. 189; Wall, 1967b, p. 67, pi. 10, figs. 20-25). 

In Alaska, T. ribstonensis has been reported from 

throughout the Schrader Bluff Formation of late 

Santonian and Campanian ages by Tappan (1962, 

p. 154) and Bergquist (1966, pi. 14).

Wall (1967a, p. 189) has defined the Trochammina 

ribstonensis zone for the northern Rocky Mountain 

foothills of Alberta; it is in the upper half of the 

Puskwaskau or Wapiabi Formation and is of late 

Santonian and early Campanian ages. At Red Bird 

this species occurs in somewhat younger beds than 

cited by Wall for the northern foothills, possibly 

owing to different times of development of favorable 

environmental conditions in the two areas. Trochammina sp. cf. T. ribstonensis reported by Wall (1967a,

p. 190; 1967b, p. 69) is from the T. ribstonensis zone 

and is slightly different from T. ribstonensis s. s.

Trochammina cf. T. wetter! Stelck and Wall 

Plate 7, figures 6, 7

Trochammina wetteri Stelck and Wall, 1955, Research Council

Alberta Kept. 70, p. 59, pi. 2, figs. 1-3, 6. 

Wall, 1967b, Research Council Alberta Bull. 20, p. 71, pi. 8, 

figs. 21-26; pi. 10, figs. 7-9.

Description. Test trochospiral to slightly streptospiral, spire generally very low and in many specimens 

not recognizable because of distortion; undistorted 

specimens unequally biconvex, spiral side being less convex than umbilical side; composed of two whorls or less, 

having generally four but sometimes three and sometimes five chambers in the final whorl; umbilicus lacking or very shallow; undistorted specimens very robust 

in shape and have a broadly rounded axial periphery 

and slightly lobulate equatorial periphery. Chambers 

slightly to moderately inflated, increasing regularly 

and abruptly in size as added, the greatest dimension 

being parallel to the axis of the test. Sutures generally 

not visible because of coarse wall texture, slightly to 

moderately depressed, straight and radial or slightly 

oblique in spiral and umbilical side views. Wall composed of moderate-sized to relatively coarse grains 

closely set in a small proportion of cement, usually 

with a wide range of grain sizes included, grains 

almost exclusively quartz, surface texture rough, color 

usually flat white but many specimens having yellow 

to brown ferruginous staining and many others appear 

gray or brownish gray because of dark-colored chamber fillings; chamber walls commonly flattened and 

test shape distorted when not filled. Aperture not 

positively observed on any specimen, presumably a 

low interiomarginal slit.

Dimensions. Average-size undistorted specimens 

have a maximum diameter of about 0.52 mm and a 

minimum diameter of 0.44 mm, measured across the 

spiral side through the center of the test, and a thickness parallel to the axis of coiling of about 0.40 mm. 

Distorted large specimens attain maximum diameters 

of 1.04 mm.

Remarks. Characteristic features of the Red Bird 

specimens are the small number of abruptly enlarging 

chambers in the final whorl, the generally coarse grain 

size, and, in undistorted or slightly distorted specimens, the low trochospiral to slightly streptospiral 

mode of coiling. These specimens are usually distorted 

to some degree, and identification of individual specimens is often difficult.
FORAMINIFERA AT RED BIRD, WYOMING C49

Among previously described species of Trocham 

mina, the Red Bird specimens most closely resemble 

T. wetteri Stelck and Wall. Points of resemblance are 

the low coil of chambers, abruptly increasing chamber 

size, and number of chambers in the final whorl. The 

major difference between the Red Bird specimens and 

T. wetteri as described and figured is in wall texture 

and composition. In T. wetteri the wall is fine textured 

and smooth, whereas in the Red Bird specimens it is 

medium to coarse grained and rough. The sutures, as 

originally illustrated and described by Stelck and 

Wall (1955, p. 59, pi. 2, figs. 1-3, 6) are curved and 

oblique on the spiral side, but Wall (1967b, p. 71, 

pi. 8, figs. 21-26; pi. 10, figs. 7-9) described the spiral 

side sutures as very slightly curved and illustrates 

them as only slightly oblique, in both respects more 

like the sutures in the Red Bird specimens. Variability 

in wall texture is observed in many species of agglutinated Foraminifera, and it may be true for T. wetteri. 

Until this can be satisfactorily established, the Red 

Bird specimens are provisionally placed in T. wetteri.

Occurrence and range. Trochammina wetteri Stelck 

and Wall was originally described from Cenomanian 

age deposits in western Canada (Stelck and Wall, 

1955). It has also been described or listed from the 

Santonian and early Campanian part of the Wapiabi 

Formation in Alberta by Wall (1967a, p. 190; 1967b, 

p. 71) and by Wall and Germundson (1963, p. 344). 

where it is associated with other characteristic species 

of the T. ribstonensis microfauna.

Genus VERNETTILINOIDES Loeblich and Tappan, 1949

Verneuilinoides cf. V. perplexus (Loeblich)

Plate 7, figures 8, 9

Vcmeuilina perplexa Loeblich, 1946, Jour. Paleontology, v. 20,

no. 2, p. 138, pi. 22, figs. 14-16. 

Verneuilinoides perplexus (Loeblich). Loeblich and Tappan,

1949, Washington Acad. Sci. Jour., v. 39, no. 3, p. 91. 

Verneuilinoides cf. V. perplexus (Loeblich) Mello, 1969, U.S.

Geol. Survey Prof. Paper 611, p. 46, pi. 1, figs la, b.

ftemarks. Although numerous specimens of this 

species were recovered, all are crushed or distorted to 

some degree. They are very clearly conspecific with 

specimens placed in Verneuilinoides cf. V. perplexus 

by Mello (1969, p. 46) from the Pierre Shale and Fox 

Hills Sandstone in South Dakota; however, fewer 

specimens have the untwisted or slightly twisted triserial arrangement of the early chambers, and some 

specimens seem to lack it altogether. Crushed paratypes of Verneuilina perplexa in the Cushman collection closely resemble the crushed Red Bird specimens, 

but a well-preserved paratype and the holotype have

prominent untwisted or slightly twisted early triserial 

chamber arrangements. Present indications are that 

these specimens and those described by Mello (1969) 

from South Dakota might best be separated as a new 

species. For the present, the Red Bird specimens are 

referred to V. perplexus in the hope that better specimens will be forthcoming which will either permit a 

confident assignment to an existing species or will 

provide the information necessary to adequately describe a new species.

The specimens from Red Bird are clearly not the 

same as the paratypes in the Cushman collection of 

Verneuilinoides bearpawensis (Wickenden), the most 

commonly reported species from beds equivalent in 

age to the Pierre Shale, especially in terms of the rate 

and degree of chamber inflation and number of chambers per whorl. Verneuilinoides sp. and Verneuilinoides cf. V. bearpawensis, reported by North and 

Caldwell (1964, p. 15, 16) from the Lea Park Formation of Saskatchewan, may be conspecific with the 

Red Bird specimens, but this cannot be clearly determined from the description and figures.

Occurrence and range. Verneuilinoides cf. V. perplexus was previously recorded from the early Maestrichtian part of the Pierre Shale and Fox Hills 

Sandstone by Mello (1969, p. 46).

Incertae sedis sp. A 

Plate 7, figure 4

Incertae sedis sp. A. Mello, 1969, U.S. Geol. Survey Prof. Paper 

611, p. 101, pi. 3, figs. la-c.

Description. Test single chambered, calcareous, 

finely perforate, radial in microstructure, circular in 

apertural view, apertural side generally moderately 

convex, opposite side very convex to subconical; some 

specimens spherical. Wall smooth, dull white. Aperture a small round hole in the center of the apertural 

surface, flush with the surface and lacks any internal 

extension.

Dimensions. The Red Bird specimens attain a 

maximum diameter of 0.108 mm perpendicular to the 

apertural axis and 0.112 mm parallel to this axis.

ffemarks. None of the seven Red Bird specimens 

is well enough preserved to show the transparent 

corona about the aperture or the glassy wall described 

for some specimens of this species by Mello (1969, 

p. 101). In every other respect, including size, these 

specimens are exactly like those described by Mello 

(1969).
C50 DESCRIPTIVE STUDY OF A CLASSIC REFERENCE LOCALITY OF THE PIERRE SHALE

Occurrence and range. This apparently distinctive 

fossil, almost certainly a foraminifer but of otherwise 

unclear taxonomic relationships, has previously been 

reported from the late Campanian and early Maestrichtian part of the Pierre Shale in South Dakota 

(Mello, 1969, p. 101).

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section from South Dakota: Jour. Paleontology, v. 7, no. 2, 

p. 215-220.

Bandy, O. L., and Arnal, B. E., 1960, Concepts of foraminiferal 

paleoecology: Am. Assoc. Petroleum Geologists Bull., v. 44, 

no. 12, p. 1921-1932, figs. 1-14.

Belford, D. J., 1960, Upper Cretaceous Foraminifera from the 

Toolonga calcilutite and Gingin chalk, Western Australia: 

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Bull. 57, 198 p., 35 pis., 14 figs.

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no. 2, p. 278-298, pis. 37-39, 5 figs.

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605 p., 55 pis., 31 figs.

Cushman, J. A., and Church, C. C., 1929, Some Upper Cretaceous Foraminifera from near Coalinga: California Acad. 

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Cushman, J. A., and Jarvis, P. W., 1928, Cretaceous Foraminifera from Trinidad: Cushman Lab. Foram. Besearch Contr., 

v. 4, pt. 4, p. 85-103, pi. 12, figs. 9-11.

 1929, New Foraminifera from Trinidad: Cushman Lab. 

Foram. Besearch Contr., v. 5, pt. 1, p. 6-17, pis. 2, 3.

Cushman, J. A., and Waters, J. A., 1927, Some arenaceous 

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pis. 10, 11.

Eicher, D. L., 1960, Stratigraphy and micropaleontology of the 

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 1965, Foraminifera and biostratigraphy of the Graneros 

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 1966, Foraminifera from the Cretaceous Carlile Shale 

of Colorado: Cushman Found. Foram. Besearch Contr., 

v. 17, pt. 1, p. 16-31, pis. 4-6, figs. 1, 2.

 1967, Depth in the Greenhorn Sea, in A symposium on

the paleoenvironments of the Cretaceous seaway in the 

western interior: Golden, Colo., Colorado School Mines, 

p. 145-172, figs. 1-14.

Franke, Adolf, 1911, Die Foraminiferen des Unter-Eocantones 

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 1966, The Bed Bird section of the Upper Cretaceous 

Pierre Shale in Wyoming: U.S. Geol. Survey Prof. Paper 

393-A, 73 p., 12 pis., 17 figs.

Jennings, P. H., 1936, A microfauna from the Monmouth and 

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Jones, D. J., ed., 1953, Microfossils of the Upper Cretaceous of 

northeastern Utah and southwestern Wyoming: Utah 

Geol. and Mineralog. Survey Bull. 47, 158 p., 16 pis., 8 figs.

LeBoy, L. W., and Schieltz, N. C., 1958, Niobrara-Pierre boundary along Front Bange, Colorado: Am. Assoc. Petroleum 

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Leslie, B. J., 1965, Ecology and paleoecology of Hudson Bay 

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Bept. 65-6, 191 p., 10 pis., 36 figs.

Loeblich, A. B., Jr., and Tappan, H. N., 1950, Foraminifera 

from the type Kiowa Shale, Lower Cretaceous, of Kansas: 

Kansas Univ. Paleont. Contr., no. 6, Protozoa, art. 3, p. 

1-15, pis. 1, 2.

Loeblich, A. B., Jr., Tappan, H. N., and others, 1964, Protista 

2, Sarcodina, chiefly "Thecamoebians" and Foraminiferida, 

Part C of Moore, B. C., ed., Treatise on invertebrate 

paleontology: New York and Lawrence, Kans. Geol. Soc. 

America and Univ. Kansas Press, 2v.

Loetterle, G. J., 1937, The micropaleontology of the Niobrara 

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Nebraska Geol. Survey Bull. 12, 2d ser., 73 p., 11 pis., 

3 figs.

Loranger, D. M., and Gleddie, Joseph, 1953, Some Bearpaw 

zones in southwestern Saskatchewan and southern Alberta, 

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figs. 1-4.

Mello, J. F., 1969, Foraminifera and stratigraphy of the upper 

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Geol. Survey Prof. Paper 611, 121 p., 12 pis., 14 figs.

Mellon, G. B., and Wall, J. H., 1956, Foraminifera of the 

upper McMurray and basal Clearwater Formations, Part 1 

of Geology of the McMurray formation: Besearch Council 

Alberta Bept. 72, 43 p., 4 figs.
FORAMINIFERA AT RED BIRD, WYOMING C51

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 1960, Foraminifera of latest Cretaceous and earliest 

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flgs. 1-63.

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 1938, The microfauna of the Sully member of the 

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 1955, Foraminifera of the Cenomanian Dunveganoceras 

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Middle Albian Foraminifera from Athabaska and Peace 

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Cenomanian Foraminifera from Peace River area, western 

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4 pis., 2 flgs.

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northern Alaska, in Loeblich, A. R., Jr., and others, Studies 

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pis. 65-71, fig. 29.

 1962, Foraminifera from the Arctic slope of Alaska,

Part 3, Cretaceous Foraminifera: U.S. Geol. Survey Prof.

Paper 236-C, p. 91-209, pis. 29-58, flgs. 10-18. 

Wall, J. H., 1960, Upper Cretaceous Foraminifera from the

Smoky River area, Alberta: Research Council Alberta

Bull. 6, 43 p., 5 pis., 1 fig.

 1967a, Paleoecology of Cretaceous marine microfaunas 

in the Rocky Mountain foothills of Alberta and British 

Columbia, in A symposium on the paleoenvironments of 

the Cretaceous seaway in the western interior: Golden, 

Colo., Colorado School Mines, p. 173-196, flgs. 1-3.

 1967b, Cretaceous Foraminifera of the Rocky Mountain

foothills, Alberta: Research Council Alberta Bull. 20, 185 

p., 19 pis., 4 flgs.

Wall, J. H., and Germundson, R. K., 1963, Microfaunas, megafaunas, and rock-stratigraphic units in the Alberta Group 

(Cretaceous) of the Rocky Mountain foothills: Bull. 

Canadian Petroleum Geology, v. 11, no. 4, p. 327-349, 4 flgs.

Wickenden, R. T. D., 1932, New species of Foraminifera from 

the Upper Cretaceous of the Prairie Provinces: Royal 

Soc. Canada Trans., 3d ser., v. 26, sec. 4, p. 85-92, 1 pi.

 1941, Cretaceous marine formations penetrated in wells 

near Lloydminster, Saskatchewan: Royal Canadian Inst. 

Trans., no. 50, v. 23, pt. 2, p. 147-155.

 1945, Mesozoic stratigraphy of the eastern plains, Manitoba and Saskatchewan: Canada Geol. Survey Mem. 239, 

Pub. 2472, 87 p., 5 pis., 2 figs.

INDEX

Page 

Aeolostreptis vitrea.. ............._.......... C21

Alabamina ---------------------------------- 16

australis australis.--------- 8, 10, 11, IB; pi. 1

dorsoplana..---------------...... ._-._---- 16

alexanderi, Proteonina..... .....-.-.----..-.... 36

Stilostomella. ............................. 45

alpha, Haplophragmoides excavata.-.--- 35, 33; pi. 4 

NeobuUmina canadensis...... 8, 10, 11, 37; pi. 6

.4ninio&acMMteS-.------------------------------ 17,30

coprolithiforme. ........................... 16

coprolithiformis. ......... 8, 10, 11, Iff, 41; pi. 1

fragmentarius.. ........................... 17

stephensoni.. ............................. 17

f ezowMS................................... 17

Ammobaculoides sp................ 8,10,11,17,- pi. 1

/InjTOod J'SCMS cretaceus. ........................ 28

kiowensis................................. 28

Anomalina.... .....-....... .. ._......... 18

jM'npwis.-.---.--....--.--.-._----------- 17

Anomalinoides.-.-.-...---------... ..---..-..- 18

pinguis... ................... 8, 10, 11, 17; pi. 1

apiculata, Lagena-------------.- 8, 10, 11, 35; pi. 5

Oolina.................................... 36

orenoceo, Bathysiphon......................... 19

aspera, Olobigerina...-..-.-...-.--.-.-.-..-..- 27 

Olobigerinella...---..... .................. 27

inflata, Eouvigerina...-------------------- 25

asperus, Qlobigerinelloides....-....-..-...--.-. 26

Astacolusjarvisellus............. 8, 10, 11, 18; pi. 1

jarvisi..................................... 18

owsfroMs,-dte&ommooMsfroZw.-.- 8, 10, 11, 25; pi. 1 

australis, Alabamina---------- 8, 10, 11, IB; pi. 1

basiplanata,Dentalina.-.--------- 8, 10, 11, 55; pi. 2

Bathysiphon orenoceo_........-.-.--.---.-.. 19

brosgei- .................... 8,10,11,18; 19; pi. 1

coropifonws-...-.-.-.-.--.-......-.-.-.-.- 19

eocenica................................... 19

0#*o......................... 8, 10, 11, 19; pi. 1

bearpawensis, Verneuilinoides........ .. ..... 49

beaumontiana, Truncatulina......-.....-.-.-.. 22

fieoMnionizonMs, Cibicides..-...-. 8, 10, 11, 50; pi. 2 

bentonensis, Gaudryina......--... .-.-.----. 23,24,41

Spiropfecfoninuna__.................. 23,24

beta, Haplophragmoides excavata..--- SS, 33,34; pi. 4 

NeobuUmina canadensis.------------- 8,10,11,88

biforaminata, Biglobigerinella......... .--.-..-- 26

BiglobigerineUa.......-----...----.--------.-- 26

biforaminata..................--.-.-..-..- 26

bonanzaensis, Haplophragmoides...------------ 30,32

bowsheri, PsamminopeUa...................... 28

brosgei, Bathysiphon.....-....-.- 8,10,11,18,19; pi. 1

Bulimina kickapooensis...--------- 8,10,11,20; pi. 1

kickapooensispingua........... ..-.-... - 20

reussinavarroensis.----------------------- 20

Buliminella...--.-.-.....-...--.-...----.-..-. 20

carseyae....................... 8,10,11, SO; pi. 1

elegantissima .-.-.-.------.----.--------- 21

vitrea..................................... 21

cakula, Haplophragmoides..-...--- 8,10,11,80; pi. 4 

California, Silicosigmoilina.-....-...-..---.--- 42,43

[Italic page numbers indicate descriptions]

Page 

canadensis, NeobuUmina..................... C37,38

alpha, NeobuUmina........... 8,10,11,87; pi. 6

beta, NeobuUmina................... 8,10,11,38

carapitanus, Bathysiphon...................... 19

carseyae, Buliminella--............ 8,10,11,50; pi. 1

Caucasina vitrea. .. ............. 8,10,11,51; pi. 2

charoides, Glomospira............. 8,10,11,57; pi. 2

corona, Glomospira........................ 27

Trochammina squamata................... 27

Cibicidesbeaumontianus........... 8,10,11,52; pi. 2

complanata, Pelosina.... ..........__...__. 41

Saccammina..---..----..-.-.- 8,10,11,41; pi. 5

constrictus, Reophax.........-...._..-........ 41

coprolithiforme, Ammobaculites................ 16

Haplophragmium......................... 16

coprolithiformis, Ammobaculites... 8,10,11,15,41; pi 

corona, Glomospira..-......................... 27

Glomospira charoides...................... 27

cretacea, Nonionella.. ......................... 40

Operculina......-_._.-_.___..___...._ 40

cretaceus, Ammodiscus.... .................... 28

Cristellaria muensteri.......................... 37

triangularis............................... 42

D

Dentalina.........-......-...-.....----.....-. 22

basiplanata...------......... 8,10,11,55; pi. 2

gracilis........................ 8,10,11,58; pi. 2

legumen...................... 8,10,11,53; pi. 2

depressa, Gyroidina........------- 8,10,11,59; pi. 3

Rotalina. ................................. 29

diagonis, Haplophragmoides.......-..--.--.... 46

Trochammina-.-------..-.--.- 8,10,11,45; pi. 6

difflugiformis, Lagenammina....... 8,10,11,85; pi. 4

Proteonina....--..-.-..----..--.----- --- 36

Reophax.................................. 36

Dorothiasmokyensis....... ........ 8,10,11,53; pi. 2

dorsoplana, Alabamina.-----------------..---- 16

E

elegantissima, Buliminella..................... 21

eocenica, Bathysiphon....-.-.-.-.--------.---- 19

Eouvigerina aspera infiata........--.--.......- 26

hispida...................... .--..-..- -. 25

sp. l._ .-. -_.- . 8, 10,11, 55; pi. 2

Eponidessp.................................. 15,16

excavata, HaplophragmoidesJS, 10,11, SO, 31,33; pi. 4 

alpha, Haplophragmoides...-.---... 85, 33; pi. 4 

beta, Haplophragmoides...------ 85, 33, 34; pi. 4

emended, Haplophragmoides...----.--.--- 30,33

excavata, Haplophragmoides.....-__- 85; pi. 4

glabra, Haplophragmoides.-------.-- 32, 88; pi. 4

kirki, Haplophragmoides.... ........... 81;pi. 4

undiflerentiated, Haplophragmoides.-..--. 81,33

excavata, Haplophragmoides excavata....... 88; pi. 4

Fissurinasp. A.................... 8,10,11, 55;pi. 2

flagleri trinitatensis, Haplophragmoides........ 32

fragmentarius, Ammobaculites......--...-.--.. 17

fraseri, Haplophragmoides..................... 34

Frondicularia watersi.....-.-.-... . 8,10,11, 55; pi. 3

futabaensis, Silicosigmoilina........ 8,10,11,45; pi. 6

Page 

Gaudryina bentonensis....-...-. -...... 623,24,41

watersi........................ 8,10,11,15; pi. 3

Gavelinella.................................... 29

girardana, Gyroidina.............. 8,10,11, 99; pi. 3

Rotalina-..--.-....--.........-.----.....- 29

glabra, Haplophragmoides.................. 30,33,34

glabra, Haplophragmoides excavata...... 32,88; pi. 4

Globigerina aspera... ----------------_--...- 27

Globigerinella aspera..-....................... 27

Globigerinelloides...-....-..- ................ 26

asperus... ...................___.__ 26

muUispina..-.--...... ._______._... 26

prairiehillensis. .. ...... ....... 8,10,11, 55; pi. 2

globosa, Gyroidina............................. 29

Trochammina......--..-..-... 8,10,11, 47; pi. 6

orbicella, Gyroidina.........---...-..-.--. 29

globulosa, Guembelina.........---.-........... 35

Heterohelix.................... 8,10,11, 85; pi. 5

Textularia................................ 35

Glomospira charoides.............. 8,10,11, 57; pi. 2

charoides corona........................... 27

corona.................................... 27

Glomospirella....-...-.......-..-..--......... 28

inconstans.................... 8,10,11,58; pi. 3

umbilicata..... ....__._....-.... ..- 28

gracilis,Dentalina.................. 8,W,U,SS; pi. 2

gravenori, Textularia.......................... 46

Guembelina globulosa......................... 35

pseudotessera............................. 35

pulchra................................... 35

uUimatumida............................. 36

Gyroidina.................. ................. 30

depressa.........-...---..-... 8,10,11,50; pi. 3

girardana...................... 8,10,11,55; pi. 3

globosa.......----------------- -------- 29

or&iceZZo------------------------------ 29

nitida..................................... 29

sp.l.... 8,10,11,59; pi. 3

H

Haplophragmium coprolithiforme.............. 16

Haplophragmoides......................... 31,34,35

bonanzaensis.....--...---...-............. 30,32

calcula.......................... 8,10,11,SO; pi. 4

diagonis.......-.....-.................... 46

excavata-.................. 8,10,11,SO,31,33; pi. 4

alpha..-.-......-...--.--..---.. 35,33; pi. 4

beta......................... 85,33,34; pi. 4

emended...._..._................ 30,33

excavata__......._............ 35; pi. 4

glabra__ ....-...- ........- 32,88; pi. 4

kirki .. --- - .- - Sl;pl. 4 

undifleientiated...................... 81,33

flagleri trinitatensis...-..-.......... _..-- 32

fraseri.................................... 34

glabra................................. 30,33,34

fcirfci .-. - 30,31,32

sp.l - - 8,10,11,84; pi. 4

sp. 2.._.._._.. .. .-...-.. 8,10,11,84; pi. 4 

sp.indet.... . - 8,10,11,85

Heterohelix globulosa............... 8,10,11,85; pi. 5

pulchra........................ 8,10,11,85; pi. 5

uttimatumida................ 8,10,11,35,85; pi. 5

hispida, Eouvigerina.......................... 25

C53
PLATE 1

FIGURES 1-3. Alabamina australis Belford australis Belford (p. C15).

la, b. Umbilical and spiral side views, X 110, USNM 687826.

2. Edge view, X 148, USNM 687828.

3. Edge view etched to show internal structures, X 194, USNM 687827.

4. Ammobaculoidesl sp. (p. C17).

Side view, X 112, USNM 687830.

5. Anomalinoides pinguis (Jennings) (p. C17).

5a-c. Spiral side, edge, and umbilical side views, X 148, USNM 687831.

6. Astacolus jarvisellus Mello? (p. CIS).

6a, b. Edge and side views, X 148, USNM 687832. 

7-9. Bathysiphon brosgei Tappan (p. C18).

7a, b. Apertural and side views, X 56, USNM 687835.

8. Side view of specimen having coarse-grained wall, X 27, USNM 

687834.

9. Side view of specimen having fine-grained wall, X 56, USNM 687833.

10. Bathysiphon vitta Nauss (p. C19).

Side view, X 88, USNM 687836.

11. Ammobaculites coprolithiformis (Schwager) (p. C16).

Side view, X 56, USNM 687829. 

12, 13. ?Buliminella carseyae Plummer (p. C20).

12a-c. Apertural and opposite side views, X 88, USNM 687838. 

13. Side view partly etched to show toothplate, X 88, USNM 687839. 

14. Bulimina kickapooensis Cole (p. C20). 

Side view, X 88, USNM 687837.
GEOLOGICAL SURVEY PROFESSIONAL PAPER 393-C PLATE 1

ALABAMINA, AMMOBACULITES, AMMOBACULOIDESl, ANOMALINOIDES, 

ASTACOLUS, BATHYSIPHON, BULIMINA, AND WULIMINELLA
PLATE 2

FIGURE 1. Caucasina vitrea (Cushman and Parker) (p. C21). 

la, b. Side views, X 219, USNM 687840. 

Ic Bottom view, X 219, USNM 687840.

2. Eouvigerina sp. 1 (p. C25).

2a-c. Edge, apertural, and side views, X 194, USNM 687847.

3. Cibicides sp. aff. C. beaumontianus (d'Orbigny) (p. C22).

3a-c. Spiral side, edge, and umbilical side views, X 112, USNM 687841.

4. Glomospira charoides (Jones and Parker) (p. C27).

4a, b. Top and side views, X 112, USNM 687852.

5. Globigerinelloides prairiehillensis Pessagno (p. C26).

5a, b. Edge and side views, X 148, USNM 687851.

6. Fissurina sp. A (p. C25).

6a, b. Apertural view (full lateral extent not shown) and side view, X 194, 

USNM 687848.

7. Dentalina legumen Reuss (p. C23).

Side view, X 70, USNM 687844.

8. Dentalina basiplanata Cushman (p. C22). 

Side view, X 70, USNM 687842.

9. Dentalina cf. D. gracilis d'Orbigny (p. C23).

Side view, X 88, USNM 687843. 

10, 11. Dorothia smokyensis Wall (p. C23).

lOa, b. Side views, X 56, USNM 687845. 

lla, b. Side views, X 56, USNM 687846.
GEOLOGICAL SURVEY PROFESSIONAL PAPER 393-C PLATE 2

CAUCASINA, CIBICIDES, DENTALINA, DOROTHIA, EOUVIGERINA, 

FISSURINA, GLOBIGERINELLOIDES, AND GLOMOSPIRA
PLATE 3

FIGURE 1, 2. Glomospirella inconstans Mello, n. sp. (p. C28).

la-c. Paratype, opposite side and edge views, X 194, USNM 687855. 

2a-c. Holotype, opposite side and edge views, X 112, USNM 687856.

3. Gaudryina watersi (Cushman) (p. C25).

3a, b. Edge and side views, X 88, USNM 687850.

4. Gyroidina sp. 1 (p. C29).

4a-c. Edge, spiral side, and umbilical side views, X 148, USNM 687859.

5. Gyroidina depressa (Alth) (p. C29).

5a-c. Umbilical side, edge, and spiral side views, X 278, USNM 687857.

6. Gyroidina girardana (Reuss) (p. C29).

6a-c. Spiral side, edge, and umbilical side views, X 268, USNM 687858.

7. Frondicularia watersi Cushman (p. C25).

7a, b. Edge and side views, X 56, USNM 687849.
GEOLOGICAL SURVEY PROFESSIONAL PAPER 393-C PLATE 3

FRONDICULARIA, GAUDRYINA, GLOMOSPIRELLA, AND GYROIDINA
PLATE 4

FIGURE 1. Haplophragmoides excavata Cushman and Waters forma alpha (p. C32). 

la, b. Side and edge views, X 56, USNM 687861.

2. H. excavata Cushman and Waters forma kirki (p. C31). 

2a, b. Side and edge views, X 194, USNM 687866.

3. H. excavata Cushman and Waters forma excavata (p. C33). 

Side view, X 88, USNM 687863.

4. H. excavata Cushman and Waters forma beta (p. C32). 

4a, b. Side and edge views, X 88, USNM 687862.

5. H. excavata Cushman and Waters forma glabra (p. C33). 

5a, b. Edge and side views, X 112, USNM 687865.

6. H. excavata Cushman and Waters.

Specimen transitional between forma beta and forma excavata. 

6a, b. Edge and side views, X 56, USNM 687864.

7. H. calcula Cushman and Waters (p. C30). 

Side view, X 63, USNM 687860.

8. Haplophragmoides sp. 1 (p. C34).

8a, b. Umbilical and spiral side views, X 278, USNM 687867.

9. Haplophragmoides sp. 2 (p. C34).

9a, b. Side and edge views, X 88, USNM 687868.

10. Lagenammina difflugiformis (H. B. Brady) (p. C36). 

Side view, X 133, USNM 687873.

11. Pseudobolivina't sp. 1 (p. C40).

lla, b. Edge and side views, X 148, USNM 687880.
GEOLOGICAL SURVEY PROFESSIONAL PAPER 393 -C PLATE 4

HAPLOPHRAGMOIDES, LAGENAMMINA, AND PSEUDOBOLIVINA 1
PLATE 5

FIGURE 1. Lenticulina muensteri (Roemer) (p. C37).

la, b. Side and edge views, X 56, USNM 687874.

2. Marginulina cf. M. texasensis Cushman (p. C37).

2a, b. Edge and side views, X 112, USNM 687875.

3. Lagena apiculata (Reuss) (p. C36).

Side view, X 140, USNM 687872.

4. Oolina obeliscata Mello (p. C40),

Side view, partly etched to show internal tube, X 185, USNM 687879.

5. Saracenaria triangularis (d'Orbigny) (p. C42).

5a, b. Side and edge views, XI 12, USNM 687885. 

6, 7. Saccammina complanata (Franke) (p. C41). 

6. Side view, X56, USNM 687883. 

7a, b. Apertural and side views, X56, USNM 687884.

8. Heterohelix globulosa (Ehrenberg) (p. C35).

8a, b. Edge and side views, X 194, USNM 687884 and 687869, respectively.

9. Heterohelix cf. H. ultimatumida (White) (p. C36).

9a, b. Edge and side views, X 194, USNM 687871.

10. Heterohelix pulchra (Brotzen) (p. C35).

lOa, b. Edge and side views, X277, USNM 687870.

11. Pseudoclavulina? meidamos Mello (p. C40).

lla, b. Side views, X125, USNM 687881.

12. Reophax sp. 1 (p. C41).

Side view, X50, USNM 687882.
GEOLOGICAL SURVEY PROFESSIONAL PAPER 393-C PLATE 5

HETEROHELIX, LAGENA, LENTICULINA, MARGINULINA, OOLINA, 

PSEUDOCLAVULINA ?, REOPHAX, SACCAMMINA, AND SARACEN ARIA
PLATE 6

FIGURE 1. Neobulimina canadensis Cushman and Wickenden var. alpha (p. C37).

la-c. Opposite side and apertural views, X 194, USNM 687876. 

2. Neobulimina spinosa Cushman and Parker (p. C39).

2a, b. Apertural and side views, X 194, USNM 687877. 

3, 4. Spiroplectammina sp. 1 (p. C43).

3a, b. Apertural and side views, X88, USNM 687888. 

4a, b. Apertural and side views, XI12, USNM 687887.

5. Silicosigmoilina futabaensis Asano (p. C42).

5a, b. Apertural and side views, X88, USNM 687886.

6. Trochammina ribstonensis Wickenden (p. C47).

6a, b. Spiral and umbilical side views, X300, USNM 687895.

7. Trochammina diagonis (Carsey) (p. 04*1).

7a, b. Umbilical and spiral side views, X88, USNM 687892.

8. Trochammina globosa Bolin (p. C47).

8a-c. Umbilical side, edge, and spiral side views, X88, USNM 687893.
GEOLOGICAL SURVEY PROFESSIONAL PAPER 393-C PLATE 6

NEOBULIMINA, SILICOSIGMOILINA, SPIROPLECTAMMINA, AND TROCHAMMINA
PLATE 7

FIGUEE 1-3. Stilostomella sp. 1 (p. C45).

la, b. Apertural and side views, X 194, USNM 687894. 

2a, b. Apertural and side views, X 112, USNM 687889. 

3. Side view, X 120, USNM 687890.

4. Incertae sedis sp. A (p. C49).

4a, b. Top and side views, X 270, USNM 687900.

5. Textularia sp. 1 (p. C45).

5a, b. Edge and side views, X 194, USNM 687891. 

6, 7. Trochammina cf. T. wetteri Stelck and Wall (p. C48).

6. Spiral side view, X 88, USNM 687896.

7a-c. Spiral side, edge, and umbilical side views, X 88, USNM 687897. 

8, 9. Verneuilinoides cf. V. perplexus (Loeblich) (p. C49).

8a, b. Side views, X 190, USNM 687899.

9. Side view, X 112, USNM 687898. 

10. Nodosaria obscura Reuss (p. C39).

lOa, b. Apertural and side views, X 88, USNM 687878.
GEOLOGICAL SURVEY PROFESSIONAL PAPER 393- C PLATE 7

NODOSARIA, STILOSTOMELLA, TEXTULARIA, TROCHAMMINA, 

VERNEUILINOIDES. AND INCERTAE SEDIS