Early Cretaceous 

(Albian) Ammonites 

From the Chitina 

Valley and Talkeetna 

Mountains, Alaska

GEOLOGICAL SURVEY PROFESSIONAL PAPER 354-D
Early Cretaceous 

(Albian) Ammonites 

From the Chitina 

Valley and Talkeetna 

Mountains, Alaska

By RALPH W. IMLAY

SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY

GEOLOGICAL SURVEY PROFESSIONAL PAPER 354-D

The Early Cretaceous (Albian) ammonites in 

southern Alaska have strong affinities with 

those in California and Oregon but are in part 

of Boreal and Eurasian origin

UNITED STATES GOVERNMENT PRINTING OFFICE, WASHINGTON : 1960
UNITED STATES DEPARTMENT OF THE INTERIOR 

FRED A. SEATON, Secretary

GEOLOGICAL SURVEY 

Thomas B. Nolan, Director

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

Washington 25, D.C. - Price SO cents (paper cover)
CONTENTS

Abstract..________________________________________ 87

Introduction _______________________________________ 87

Biologic analysis____________________________________ 87

Stratigraphic summary ______________________________ 88

Talkeetna Mountains ___________________________ 88

Chitina Valley__________________________________ 88

Ammonite faunules and correlations.__________________ 89

Leconteites modes. MS and Puzosigella faunule________ 89

Moffitites robust us and Leconteites deansi faunule___ 91

Ammonite faunules and correlations Continued

Bretrericeras breweri and B. cf. B. hulenense faunule__ 

Frebnhliceros singulare faunule____________________

Other Albian faunules.__________________________

Comparisons with other faunas_______________________

Geographic distribution._____________________________

Summary of results _________________________________

Systematic descriptions______________________________

References. ________________________________________

Index _____________________________________________

ILLUSTRATIONS

PLATE 11.

12.

13.

14.

15.

16.

17.

18.

[Plates follow index]

Phyllopachyceras, Calliphylloceras, Anagaudryceras, Valdedorsellal', and Hypophytloceras.

Callizoniceras, Kossrnatella, Ptychoceras, and Tetragonites.

Moffitites.

Beudanticeras, Moffitites, and Freboldiceras.

Kennicottia.

Puzosia and Beudanticeras.

Desrnocerasl and Brewericeras.

Parasilesites, Hulenites, Arcthoplitesl, and Lemuroceras.

19. Leconteites, Aucellina, Puzosigella, and Cleoniceras.

FIGURE 21. Correlation of the Albian faunas of the Chitina Valley and Talkeetna Mountains.

22. Index map of the principal areas_______ ________________________________

23. Index map showing Albian localities in the Chitina Valley____________________

24. Index map showing Albian localities in the Talkeetna Mountains-______________

91

92

93

93

93

93

97

111

113

90

94

95

97

TABLES

Page 

TABLE 1. Ammonite genera in the Albian beds of the Chitina Valley, Talkeetna Mountains, Alaska, showing biological

relationships and relative numbers available for study._____-_---_-__-_-_____----------_------__------- 88

2. Localities at which ammonites were collected from the Albian strata of the Chitina Valley and Talkeetna Mountains. ________________________________________________________-___-_---___-_-_---___-_--------_-- 96

3. Geographic distribution of early and middle Albian ammonites from the Chitina Valley and Talkeetna Mountains, Alaska,_________________________________________-____--___--___--__--------_-___----------- 98
SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY

EARLY CRETACEOUS (ALBIAN) AMMONITES FROM THE CHITINA VALLEY AND

TALKEETNA MOUNTAINS, ALASKA

By RALPH TV. IMLAY

ABSTRACT

The Early Cretaceous (Albian) ammonites of the Chitina 

Valley and Talkeetna Mountains, Alaska, belong to four faunules ranging in age from early to early middle Albian.

The lowest faunule in the Chitina Valley is characterized by 

Lecontcites modestus (Anderson) and by species of Pusosigella 

that permit a close correlation with the Leconteites lecontei 

zone of California and Oregon and hence with the early Albian 

of Eurasia. Moffitites crassus Imlay, n. sp., also may be characteristic of this faunule.

The next higher faunule in the Chitiua Valley is characterized 

by Moffitites robust us Imlay and Leconteites deansi (Whiteaves). It is probably only slightly younger than the Leconteites lecontei zone of California and Oregon. The next higher 

Albian faunule in the Chitina Valley is characterized by a 

coarsely ribbed variant of Brewericeras breweri (Gabb) that 

suggests approximate correlation with the Brewericeras hulenense zone in California. An early Albian age for this faunule 

is indicated by the ammonites Valdedorsella, Parasilesites, and 

subgenus Subarcthoplites.

In the Talkeetna Mountains the only Albian representative 

is the FreboMiceras singulare faunule, which is characterized 

by excellently preserved specimens of Beudanticeras glabrum 

(Whiteaves), FreboMiceras singulare Imlay, and Lemuroceras 

talkeetnanum Imlay, n. sp. These are either identical with or 

closely related to ammonites in the western interior of Canada 

beneath beds that contain Gastroplitea. The faunule is probably younger than the Lemuroceras belli zone of Canada and 

the Brewericeras breweri faunule of the Chitina Valley, but 

the evidence is not conclusive. If it is younger, its age is 

probably early middle Albian.

The Albian ammonite faunules of the Chitina Valley have a 

provincial aspect owing to the presence of genera not yet found 

outside the Pacific coast of North America. These include 

Moffitites, Kennicottia, Brewericeras, Leconteites, Pusosigella, 

Hulenites, and Parasilesites. A marine connection with the 

boreal province through Canada or Alaska is indicated, however, by the presence of such ammonites as Lemuroceras (Subarcthoplites) and Callizoniceras. In addition the faunules include many genera that are distributed nearly worldwide, or 

that do not characterize any particular province. The Albian 

ammonites of the Talkeetna Mountains likewise exhibit a 

provincial aspect, but in contrast to those from the Chitina 

Valley, the relationships are strong with the western interior of 

Canada and with northern Alaska.

These faunal relationships imply that the Albian sea that 

covered southern Alaska had broad connections with seas in 

the western interior of the continent, in California and Oregon, 

and in Asia.

INTRODUCTION

This study of the Early Cretaceous (Albian) ammonites of the Chitina Valley and Talkeetna Mountains in the southeastern part of the main body of 

Alaska is based on collections made by members of the 

Geological Survey since 1899. Thanks are due to Leo 

G. Hertlein and Dallas G. Hanna, of the California 

Academy of Sciences in San Francisco, for the privilege of examining the type specimens of certain Albian 

ammonites. Correlations with Albian beds in California were influenced by discussions with Michael 

Murphy of the University of California at Kiverside. 

Some notes on the Cretaceous of the Chitina Valley 

prepared by Don J. Miller, of the U.S. Geological Survey, were very useful in determining the stratigraphic 

distribution of the Albian faunules.

The Albian ammonites of the Chitina Valley and 

Talkeetna Mountains are of exceptional interest because they are highly varied, and well preserved and 

represent an association of ammonites that occur elsewhere in distinct faunal provinces and are associated 

with plants that paleobotanists maintain are of Jurassic age. Description of the ammonites is justified, 

therefore, as documentation of their Albian age and 

that of the associated plants, as an aid in geologic 

mapping, and as a means of interpreting local geologic history in terms of events elsewhere. The fact 

that the ammonite faunules are derived from various 

provinces should prove useful in making interregional 

and intercontinental correlations.

BIOLOGIC ANALYSIS

The Albian ammonites from the Chitina Valley and 

Talkeetna Mountains include 379 specimens, of which 

308 are specifically identified and 61 are compared to

87
88 SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY

described species. Among these the Phylloceratidae 

are represented by 28, the Tetragonitidae by 40, the 

Ptychoceratidae by 2, the Desmoceratidae by 205, the 

Silesitidae by 5, the Kossmaticeratidae by 4, and the 

Hoplitidae by 95. The distribution of these specimens 

by genera, subfamilies, and families is shown in table 1. 

The table shows that the Desmoceraticlae is the dominant family as regards individuals, species, and genera. 

It is characterized by the presence of such genera as 

Moffitites, Freboldweras, Kennicottia, and Brewericeras, which have not been recorded outside the Pacific coast of North America. It includes, however, 

such Old World genera as VaMedorsella, Callizoniceras, Puzosia, and Desmoceras. The species of Beudanticeras present have certain peculiarities that distinguish them from European species, but are judged 

not to be of sufficient importance to warrant generic 

differentiation.

TABLE 1. Ammonite genera in the Albian beds of the Chitina 

Valley and Talkeetna Mountains, Alaska, showing biological 

relationships and relative numbers available for study

Family

Silesitidae_---______-_-

Hoplitidae- ___.-____.__

Subfamily

Qastroplitinae_ _ _

Genus

Beudanticeras 

(Grantziceras) .

Lemuroceras. .......... 

Lemuroceras (Sabarcthoplites).

Specimens

4

1

23

32

3

1

4

2

2

11

38

4

16

92

9

5 

27

1

5

4

1

16

73

1 

2

2

Next in importance is the family Hoplitidae in 

which the genera PuzosigeHa and Leconteites dominate 

in individuals and in species. These genera have not 

yet been reported elsewhere than the Pacific coast of 

North America. Of particular importance is the presence of typical representatives of the genera Cleoniceras and Lemuroceras. There are also, two specimens 

belonging to Subarcthoplites Casey (1954, p. Ill) 

which is herein considered to be a subgenus of Lemuroceras.

The families Phylloceratidae and Tetragonitidae are 

of comparatively minor importance, and the other 

families in table 1 are represented only by single species 

and a few specimens. It is interesting, however, that

Parasilesites and Hulenites have not been recorded outside the Pacific coast of North America.

The absence of PseudoleymerieUa Casey (1957, p. 

35; Whiteaves, 1893b, p. 444, pi. 7, figs. 2, 2a, b), which 

occurs in early Albian beds in the Queen Charlotte 

Islands, as well as the absence of Douvitteiceras, which 

is common in California, possibly reflects insufficient 

collecting.

STRATIGRAPHIC SUMMARY 

TALKEETNA MOUNTAINS

Albian ammonites have been found in the Talkeetna 

Mountains at only two places, one near the head of 

Billy Creek and the other near the head of Flume 

Creek. They occur in concretions in the basal 125 

feet of a shale and silt stone unit above 150 feet of 

sandstone that contains coaly beds of unknown age. 

This sandstone overlies 550 feet of sandstone of Valanginian age that overlies the Nelchina limestone of 

Valanginian age. From the siltstone 250 feet above 

the concretions, specimens of Inoceramus of Late Cretaceous age have been obtained. There is a possibility 

that the concretions have been reworked from older 

beds (Arthur Grantz, written communication, Dec. 29, 

1958). Nevertheless, the presence of Albian ammonites, 

even locally, in the Talkeetna Mountains suggests that 

Albian beds once existed nearby and may now exist in 

the subsurface of the Copper Kiver basin east of the 

mountains.

CHITINA VALLEY

Albian beds in the Chitina Valley have been identified only in the upper (eastern) 50 to 60 miles of the 

valley east of the Kuskulana Eiver. The main areas 

of outcrop, from west to east, occur near Kuskulana 

Pass, along Fohlin and Bear Creeks west of Kennicott Glacier, near the head of McCarthy Creek, and 

near the foot of Nizina Glacier. Several other areas of 

outcrop occur from 25 to 35 miles south of the Nizina 

Glacier near the headwaters of Young Creek and near 

the mouth of Canyon Creek. The extent of outcrop 

in most of these areas is not known. However, the 

numerous collections obtained near Kuskulana Pass 

and the creeks immediately to the west are all of Albian age except for some fossils obtained 5,800 feet S. 

39° E. of the mouth of Slatka Creek (Mes. loc. 8939) 

that are probably of Late Cretaceous age. In the 

area along Fohlin and Bear Creeks, all the Albian fossils were obtained near or north of Bear Creek and its 

east-northeast projection.

The total thickness of the Albian beds in the Chitina 

Valley is not known, but it is probably only a few 

hundred feet. In the section measured by Moffit (1938,
CRETACEOUS AMMONITES FROM CHITINA VALLEY AND TALKEETNA MOUNTAINS 89

p. 71) 011 Fourth of July Creek west of Kennicott 

Glacier, only the lower 150 to 250 feet of massive brown 

sandstone and crumbly gray shale have furnished 

Albian fossils. The thickness of Albian beds at the 

head of McCarthy Creek must be slight also because 

that area has furnished many collections of Late Jurassic (Oxfordian to Kimmeridgian) age (TJSGS Mes. 

Iocs. 11373, 11374, 11376, 11378, 11380, 14032, 14034, 

14035, 14495-14497) and Early Cretaceous (Valaiiginian) age (USGS Mes. Iocs. 2172, 2209, 11375, 11377, 

14031, 14500-14502), but only one collection (USGS 

Mes. loc. 6313) of Albian age. That collection was 

from a sandstone, but the preservation of the fossils 

indicates that they were obtained from a concretion 

in the sandstone. A collection at the bend of Young 

Creek (Mes. loc. 9492), obtained from concretions in 

brown sandstone, is younger than any of those obtained on Fohlin Creek, Bear Creek, or near Kuskulana Pass, but the thickness of the stratigraphic unit 

involved is not known.

The 352 feet of sandstone and shale exposed at the 

base of the Cretaceous near the mouth of Canyon 

Creek (Moffit, 1938, p. 73) (Mes. Iocs. 9481, 9485- 

9487) contains fossils of late Albian to Ceiiomaniaii 

ages, according to Tatsuro Matsumoto (1959, p. 85, 

86), and are therefore appreciably younger than the 

early Albian beds exposed in a similar appearing sequence at the base of the Cretaceous on Fourth of July 

Creek. Interestingly, Mesozoic locality 9489, about 3 

miles west of the mouth of Canyon Creek, contains 

early Albian fossils identical with those near the base 

of the Cretaceous on Fourth of July, Bear, and Fohlin 

Creeks. Judging from published illustrations (Moffit, 

1938, pi. 2; Moffit and Overbeck, 1918, fig. 2, on p. 27, 

and pi. 3), Mesozoic locality 9489 should be somewhat 

lower stratigraphically than locality 9487 at the mouth 

of Canyon Creek along the same belt of outcrops, but 

the stratigraphic interval between these localities 

cannot be measured from the map. These occurrences 

suggest, however, that the basal beds of the Cretaceous 

sequence in the Chitina Valley are of different ages 

from place to place and that the Albian part of the 

sequence is not very thick.

AMMONITE FAUNULES AND CORRELATIONS

LECONTEITES MODESTUS AND PUZOSIGELLA 

FAUNULE

This faunule (fig. 21) is represented in the Chitina 

Valley near Bear, Fohlin, and Fourth of July Creeks 

at USGS Mesozoic localities 8877, 9971, 11389, and 

14468 by the ammonites Leconteites modestus (Andersen), Puzotigdla cf. P. rogersi (Hall and Ambrose), 

P. cf. P. perrinsmithi (Anderson), P. cf. P. taffi

(Andersoii), and Anagaudryceras aurarium (Anderson) . The faunule may be represented, also, by Moffitites cmssns Imlay, n. sp., obtained 1 mile north of Bear 

Creek at USGS Mesozoic locality 14487 and 3y2 miles 

southeast of Kuskiilana Pass at USGS Mesozoic locality 14477.

These ammonites are usually associated with many 

specimens of the pelecypod Aucellina (Moffit, 1938, 

pi. 10, figs. 4, 5), which genus in reports dealing with 

the Chitina Valley has generally been compared with 

^Aucella" pallasi (Keyserliiig), or " Aucella," crassicollis (Keyserliiig) (Martin, 1926, p. 336, 347, 348; 

Moffit, 1938, table facing p. 80). It includes all specimens previously assigned to ^Aucella* except those 

from the Late Jurassic and Early Cretaceous (Valanginiaii) localities listed herein under the heading 

"Stratigraphic summary/ 1

The localities listed under the Leconteites modestus 

-faunule are all near the contact of Cretaceous with 

Triassic rocks and, judging from Moffit's map (1938, 

pi. 2), are distinctly lower stratigraphically than most 

of those of the succeeding faunule typified by Moffitites robusfus Imlay. At a few places, however, the 

fossils of one faunule were found near those of the 

other, as at USGS Mesozoic localities 8877 and 8878. 

This is not surprising considering that the total thickness of beds involved in both faunules is not more 

than 300 feet in most places (Moffit, 1938, p. 71, 78).

The beds containing Leconteites modestus (Anderson) and Puzosigella spp. may be correlated with the 

Leconteites leconfei zone (Murphy, 1956, p. 2118, fig. 

6) in California and Oregon because of the presence 

of the genera Leconteites and PnzosigeHa and of the 

species Leconteites modestus (Anderson). Also, the 

presence of Anagaudryceras aurarium (Anderson) is 

normal in that zone, although it ranges higher in California into the zone of Bretnericeras Inrtenense.

The age of the Leconteites lecontei zone is either 

early or early middle Albian as shown by the presence 

of the ammonite DourRleiceras, which in Europe 

ranges from the upper part of the LeymerieWa, tardefnrcata zone into the middle of the Hoplites dentatus 

zone (Spath, 1930, p. 60-65; Collignon, 1949, p. 110- 

114; Breistroffer, 1947, p. 27, 28). An early Albian 

age for the Leconteites lecontei zone is favored, however, by the presence of File site*, which normally occurs in beds older than Albian, and by the presence of 

Donr'Jlcicerax in the next two overlying zones, which 

may be correlated with the upper part of the range 

of the genus in Europe. The presence of Anagaudryceras and Tetragonites indicates an age not older than 

Albian.
90 SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY

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CRETACEOUS AMMONITES FROM CHITINA VALLEY AND TALKEETNA MOUNTAINS 91

MOFFITITES ROBUSTUS AND LECONTEITES DEANSI 

FAUNULE

This faunule (fig. 21) is represented in the Chitina 

Valley at many localities along Bear and Fohlin Creeks 

(USGS Mes. loc. 31-47, 2191, 2201, 8872, 8873, 8875, 

8876, 8878, 8880, 9966, 9967, 9967a, 9972, 9973, 9976, 

9978, 14471, 14484, 14485), and at single localities along 

Fourth of July Creek (USGS Mes. loc. 14467), Trail 

Creek (USGS Mes. loc. 9950), and 3 miles west of the 

mouth of Canyon Creek (USGS Mes. loc. 9489). The 

most common ammonites are Moffitites robustus Imlay, 

Kennicottia bifurcata Imlay, Leconteites dennsi 

(Whiteaves), L. crassicostatus Imlay, n. sp., and Angaudryceras aurariuin (Anderson). Somewhat less 

common are Phyllopachyceras cf. P. shastalense (Andersoii), Calliphylloceras cf. C. aldersoni (Anderson), 

Ptychoceras cf. P. laeve (Gabb), Callizoniceras (WoJlemanniceras) alasJcamim Imlay, n. sp., C. (W.) fohUnen.se Imlay, n. sp., Kennicottia rugosa Imlay, n. sp., 

Pnzosia sp., and Leconteites aff. L. deansi (Whiteaves). 

These ammonites are associated with the pelecypod Aucellina (pi. 19, figs. 28-32) which locally occurs in great 

numbers and has been obtained at many more localities than the ammonites.

The Moffitites robustus faunule is of early Albian 

age only a little younger than the underlying faiimile 

containing Leconteites modestus (Anderson) and Puzosigella. This is indicated by the close stratigraphic 

association of the faunules and by the presence in both 

of the genus Leconteites, which in California has been 

found only in the Leconteites lecontei zone of early 

Albian age. Similarly, the presence of Callizoniceras 

(Wollemanniceras) is excellent evidence that the Moffitites robustus faunule is not younger than early Albian 

(Wright, 1957, p. L363).

The Moffitites robust us faunule is not correlated with 

either the Leconteites lecontei zone or the overlying 

Brewericeras hulenense zone in California (Murphy, 

1956, p. 2118) because the only species in common with 

those zones is Anagaudryceras aurarium (Anderson) 

and because those zones may be correlated respectively 

with the Leconteites modestus faunule and the Brewericeras breweri faunule of the Chitina Valley. Both 

stratigraphically and faunally, therefore, the Moffitites robustus faunule appears to occupy a position intermediate between the California zones in question. 

Such a position is not in conflict with recent studies in 

California. Inspection of the zonal map prepared by 

Murphy (1956, fig. 5 on p. 2109) for the Cottonwood 

area near Ono, Calif., shows that there is ample space 

stratigraphically for another faunule zone between the 

Leconteites lecontei and Brewericeras hulenense zones.

534624 O 60 2

BBEWEBICEBAS BBEWEBI AND B. CF. B. HULENENSE 

FAUNULE

This faunule is represented in the upper part of the 

Chitina Valley at USGS Mesozoic localities 9480 and 

9492 near the head of Young Creek, at USGS Mesozoic 

locality 14514 near the foot of Mzina Glacier, and 

probably at USGS Mesozoic locality 6313 near the 

head of McCarthy Creek. The fossils at localities 9492 

and 6313 were obtained from concretions in sandstone, 

but the characteristics of the beds at the other localities is not known. As all these localities are many 

miles from the localities that furnished Leconteites and 

Moffitites, the thickness of the stratigraphic unit involved is not known.

The fossils in the faunule characterized by Breioericcras brewer? (Gabb) are listed by localities as follows:

Plti/llopacli t/ccrax cl\itinat\um Imlay. n. sp_ 9492 

HypopJtiillocfras cf. H. californicum (Auderson) 9492 

Callipln/Uoccra* ni~inauum Imlay, n. sp. 9492 

Anagaudryc-cras sp. indet___ 6313 

KoxNtiiatcIla cappxi Imlay, n. sp__ ___ 9492, 14514 

Tctraf/onitcx aff. T. timotJ>eann« (Pictet) 9492 

Yalflcflorxcllu'i irJtitcaresi Imlay, n. sp.____ 9492 

Puzonia, aldftkfuni Imlay, n. sp__- 9492 

Brcircriccras breiceri (Gabb)______ 9492

cf. B.JiHlcncHse (Anderson)_________ 6313,9492,14514 

TtcsmrK'cras sp. juv_________-_- 9492 

cftitei* IniJlatus Imlay, n. sp_______ 9492

irrcf/uJarifs Imlay, n. sp____ - 9492 

t'Hitcft cf. H. rrcsiilei (Anderson)________ 9480,9492 

Clconiccrtix orcrbecki Imlay, n. sp___ 9492 

Lcnturocrrax ( Hnlarctlioplites) aff. L. Jielli McLearn 9492 

Arctltoplitcx'? sp_______________________ 9492

The only abundant ammonites among those listed 

are Puzosift alaslccinn Imlay, n. sp., CalUphyllocems 

nizhianum Imlay, n. sp., Brewericeras breweri (Gabb), 

and B. cf. B. hulenense (Anderson). All other species 

are represented by five specimens or less. Associated 

with these ammonites are many other mollusks (Moffit, 

1918, p. 40), of which the most significant stratigraphically are small specimens of Inocernmus that resemble immature specimens of /. comancheanus 

Cragin (equals /. anglicus Woods). Also, of stratigraphic significance is the absence of the pelecypod 

Ancellino, which is abundant in the older beds containing Leconteites and Moffitites.

The beds in the Chitina Valley that contain Brewericeras breweri (Gabb) and B. cf. B. hulenense (Anderson) are considered to be approximately equivalent to 

the zone of B. hulenense in northern California (Murphy, 1956, p. 2118, fig. 6) because they both contain 

the same coarsely ribbed variant of B. breweri (Gabb) 

that was illustrated by Whiteaves (1876, p. 21, pi. 1, 

figs. 2, 2a, 3, 3a) from the Queen Charlotte Islands. 

Also, the specimens herein compared to B. hulenense 

(Anderson) are probably immature examples of that
92 SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY

species rather than of B. haydeni (Gabb). Otherwise 

the Alaskan Brewericeras l>reweri faunule differs from 

the ammonites in the B. Jiulenense zone in California 

by the absence of the genus Douvilleiceras and the 

presence of the genera Valdedorsella, Parasilesites, 

Hulenites, Cleoniceras, and Lemuroceras (SubarcthoThe Brewericeras liulenense zone in California may 

be correlated with the Douvilleiceras mammillatum 

zone in Europe on the basis of containing an abundance of Douvilleiceras and of being in the middle of 

the local range of Douvilleiceras. Similarly the underlying Leconteites lecontei zone may be correlated 

with the lowest occurrence of Douvilleiceras in Europe 

in the upper part of the Leymeriella tardefurcata zone. 

If these correlations are correct, the age of the B. 

hulenense zone should be late early Albian, according 

to the classification used by Wright (1957, p. L128) 

and Breistroffer (1947, p. 51, 53), or early middle 

Albian, according to the classification used by Spath 

(1941, p. 668).

Concerning the age of the beds in Alaska that contain Brewericeras breweri (Gabb), an early rather 

than middle Albian age is indicated by the presence of 

such genera as Valdedorsella and Lemuroceras (Subarcthoplites). Of these, Valdedorsella has not been 

found above the lower Albian in Europe; Parasilesites 

belongs in a family that is not known above the lower 

Albian; and the subgenus /Subarcthoplites occurs in 

northern Alaska about 600 feet below the lowest known 

occurrence of Cleoniceras, which ranges through more 

than 2,500 feet of strata (Imlay, 1960).

FBEBOLDICEBAS SINGULABE FAUNULE

This faunule is represented in the Talkeetna Mountains by the ammonites Tetragonites sp., Freboldiceras 

singulare Imlay, Beudanticeras glabrum (Whiteaves), 

B. (G-rantziceras) multiconstrictum, Imlay; and Lemuroceras talkeetnanum Imlay, n. sp. The faunule is 

of unusual interest because of the excellent preservation of the specimens, because its component species 

show close affinities with Albian species in the western 

interior of Canada and in India, * and because its genera ~

and species have no known affinities with the Albian 

ammonites of California or Oregon, although they 

occur in the same marine basin as the Albian ammonites 

of the Chitina Valley that are closely related to ammonites in California and Oregon.

The age of the ammonite faunule in question from 

the Talkeetna Mountains is either early Albian or early 

middle Albian on the basis of comparisons with similar 

ammonites in the western interior of Canada. The 

presence of Beudanticeras glabrum (Whiteaves) indicates a correlation with Albian beds in Canada below

the lowest occurrence of the ammonite Gastroplites in 

the Harmon shale member of the Peace River formation (Henderson, 1954, p. 2285, 2286; Stelck and 

others, 1956, p. 10, 12). The resemblance of Frel)oldiceras singulare Imlay to "Lemuroceras" irenense 

McLearn (1945, pi. 5, fig. 5; 1948, p. 2) from the upper 

part of the Moosebar formation of British Columbia 

(Stelck and others, 1956, p. 10) suggests an age slightly 

younger than that of Lemuroceras (Subarcthoplites) 

belli McLearn (1945, pi. 3, figs. IT, 18; 1948, p. 2) from 

the Clearwater formation and the upper part of the 

Loon River formation (McLearn and Kindle, 1950, 

p. 86, 93). However, the resemblance of Lemuroceras 

talkeetnanum Imlay, n. sp., to Lemuroceras cf. L. indicuni Spath (McLearn, 1945, pi. 5, fig. 4) from the 

lower part of the Loon River formation (Stelck and 

others, 1956, p. 6, 11, 14) suggests an age slightly older 

than that of Lemuroceras belli McLearn.

The fact that Lemuroceras talkeetnanum Imlay, n. 

sp., is remarkably similar to L. indicum (Spath) (1933, 

p. 801, pi. 129, fig. 5) from India and Madagascar 

(Collingnon, 1949, p. 68, 69, pi. 12, figs. 2, 2a, b, pi. 14, 

fig. 2) suggests that it is of nearly the same age as that 

species and that the Freboldiceras singulare faunule 

may be correlated with the Old World Douvilleiceras 

mammillatum zone. As just discussed, however, correlation with that zone seems reasonable, also, for the 

Brewericeras hulenense zone in California and for the 

B. breweri faunule in the Chitina Valley which have 

an entirely different ammonite assemblage than the 

faunule in the Talkeetna Mountains. This difference 

is especially significant for correlation purposes considering that the Albian beds of the Talkeetna Mountains and of the Chitina Valley were deposited in the 

same basin and, therefore, that the ammonites in those 

beds should not differ greatly provided they are of the 

same age.

Therefore, the Albian fossils from the Talkeetna 

Mountains are either slightly younger or slightly older 

than the Brewericeras breweri faunule in the Chitina 

Valley. The matter cannot be settled definitely on the 

basis of available evidence, but a younger age is suggested by the fact that in northern Alaska the beds containing Lemuroceras belli McLearn are underlain by 

beds containing Albian ammonites that are considerably different than those in the Talkeetna Mountains. 

Accordingly the Freboldie'eras singulare faunule is 

probably younger than the Lemuroceras belli zone of 

Canada and northern Alaska and should be sought in 

the upper part of the Moosebar formation and in the 

Gates formation of British Columbia and in the Notikewin member of the Peace River formation of Alberta. Such a correlation would agree with the general
CRETACEOUS AMMONITES FROM CHITINA VALLEY AND TALKEETNA MOUNTAINS 93

resemblance of Freboldiceras singulare Imlay to "Lemuroceras" irenense McLearn.

OTHER ALBIAN FAUNULES

Some fossil collections of late Albian to Cenomanian 

ages have been obtained from the valley of the Nizina 

Glacier (USGS Mes. Iocs. 14038, 14040, 14511, 14515) 

and about 30 miles south-southeast of that glacier in 

an area northwest of Gibraltar Hill (USGS Mes. Iocs. 

9481, 9485-9487). Most of the fossils were considered 

to be of Albian age by Imlay and Reeside (1954, p. 

230), but recent studies by Matsumoto (1959, p. 85, 

86) show that USGS Mesozoic locality 9481 contains 

fossils of probable Cenomanian age and that the other 

localities contain long-ranging species that could be 

of late Albian or of Cenomanian age. A definite age 

determination must await additional collecting. ~ Considering these age limitations, it is interesting that 

plant fossils obtained from USGS Mesozoic localities 

9481 and 9486 and from many localities of early to 

middle Albian age in the Chitina Valley have been 

identified by F. H. Knowlton as definitely Late Jurassic (Moffit and Overbeck, 1918, p. 42, 44; Martin, 1926, 

p. 336-346; Moffit, 1938, p. 88).

COMPARISONS WITH OTHER FAUNAS

The Albian ammonites from the Chitina Valley belong in the same faunal province as the Albian ammonites of California and Oregon as shown by the 

presence of the genera Brewericeras, Hulenites, Puzosigella, and Leconteites. However, some kind of faunal 

connection with the western interior of Canada and 

with northern Alaska is shown by the presence of 

Lemuroceras (Subarcthoplites) in association with 

Brewericeras. Also the presence of Callisoniceras, 

known elsewhere only from Greenland and northwest 

Europe, suggests some kind of connection through 

Canada or northern Alaska with the boreal province. 

The genera Moffitites and Kennicottia have not yet 

been reported from California or Oregon but are present in U.S. Geological Survey collections from the 

Queen Charlotte Islands and may be expected farther 

south. Most of the other genera are widely distributed 

in many parts of the wT orld.

The few Albian ammonites from the Talkeetna 

Mountains in contrast with those from the Chitina 

Valley belong in the same faunal province as "he Albian ammonites of the western interior of Canada and 

of northern Alaska and have not yet been found in 

California and Oregon. This is shown by the presence 

of Beudanticeras glabrwn (Whiteaves), which is common in the western interior of Canada, and of species 

of Beudanticeras, Freboldiceras, and Lemuroceras that

are closely similar to Canadian species. Such a relationship is surprising because any Albian beds in or 

near the Talkeetna Mountains must have been deposited in the same marine sedimentary basin as the 

Albian beds of the Chitina Valley. These facts mean 

either that there was some mixing of the Albian faunas 

of the interior region, which are of boreal origin, with 

those of the Pacific coast during Albian time or that 

the faunas were actually not distinct. In this connection the presence of a species of Lemuroceras in the 

Talkeetna Mountains similar to L. indicum (Spath) 

from India and Madagascar (Spath, 1933, pi. 128, 

figs. 4a, b, 5a, b; Collignon, 1949, pi. 12, figs. 2, 2a, b, 

pi. 14, figs. 2) and to a species from the western interior of Canada (McLearn, 1945, pi. 5, fig. 4) suggests 

that the Albian ammonite faunules of the western interior of Canada and of northern Alaska may have had 

a much wider distribution than now realized.

In summation, the Albian ammonite assemblage in 

southern Alaska is predominantly related to the Albian 

ammonite assemblage in California and Oregon, but 

includes some genera and species that are boreal in 

origin, and others that occur in Albian beds in many 

parts of the world.

GEOGRAPHIC DISTRIBUTION

The occurrence by area and locality of the 45 species 

described in this report is indicated in table 3. The 

position of the two known areas of lower to middle 

Albian rocks in the southeastern part of the main 

body of Alaska is shown in figure 22, and the general 

position of each locality is shown in figures 23 and 24. 

The positions of such localities as 2147, 2173, 2191, 

2201, and 6313 may be in error by a mile or more because of inadequate field descriptions. Descriptions 

of the individual localities are given in table 2. This 

list does not include any localities mentioned in the text 

under such ages as Late Jurrassic, Early Cretaceous 

(Valanginian), or late Albian to Cenomanian. The 

description of such localities may be found in U.S. 

Geological Survey Bulletin 894 on pages 83-88.

SUMMARY OF RESULTS

The Early Cretaceous (Albian) ammonites from the 

Talkeetna Mountains and the upper part of the Chitina 

Valley discussed herein are well preserved and highly 

varied. They include 24 genera and 45 species. Of 

these species 18 are described as new. Of the 24 genera, 

4 were described as new in a preliminary paper (Imlay, 1959) published during the course of this study.

Among the Albian ammonites the family Desmoceratidae is dominant in numbers, genera, and species. It 

is characterized by the genera Moffitites* Freb oldie eras,
94 SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY

O C E

158°/SA154° 

,\° "

OCEAN

FIGURE 22. Index map of the main areas of Albian fos sils in the southeastern part of the main body of Alaska.

Kennicottia^ and Brewericeras^ which have not been 

recorded outside of the Pacific coast of North America. 

It includes, also, the Old World genera CaMzoniceras, 

Puzosia, Beudanticeras, and probably Valdedorsella 

and Desmoceras. Next in importance among the Albian ammonites is the family Hoplitidae. It is characterized by the genera Leconteites and PuzosigeHa, 

which have been found to date only on the Pacific coast 

of North America, but includes the widely distributed 

genera Cleoniceras and Lemuroceras. Of considerable 

lesser importance are the Phylloceratidae and Tetragonitidae. The Ptychoceratidae, Silesiticlae, and Kossmaticeratidae are represented by only a few specimens. 

The Albian beds include four ammonite faunules. 

In the Chitina Valley the faunules, from oldest to 

youngest, are characterized by 1, Leconteites modestus 

(Anderson) and Puzosigella spp.; 2, Moffitites robustus 

Imlay and Leconteites deanxi (Whiteaves) ; 3, 

Brewericeras breweri (Gabb) and B. cf. B. hulenense 

(Anderson). In the Talkeetna Mountains occurs a 

fourth faunule characterized by Freboldiceras singulare Imlay. This faunule is probably younger than 

the other faunules, but the evidence is not conclusive.

The two lower faunules are associated with the pelecypod AucelUna.

The faunule characterized by Leconteites modestus 

and Puzosigella spp. is correlated with the Leconteites 

lecontei zone in California and Oregon and is of early 

Albian age.

The faunule characterized by Mofjitites robustus Imlay and Leconteites deanxi (Whiteaves) is considered 

to be intermediate in age ~ between the Leconteites lecontel zone and the Brewericeras hulenense zone in 

California. An age not younger than earlier Albian is 

indicated by the presence of the genus Oallizoniceras. 

The faunule characterized by Brewericeras breweri 

(Gabb) and B. cf. B. hulenense (Anderson) is approximately equivalent to the Brewericeras hulenense 

zone in California because it contains the coarsely 

ribbed variant of Brewericeras breweri (Gabb) identical with that in the B. hulenense zone. The faunule 

in the Chitina Valley differs in other respects, however, and may not be an exact equivalent. Its age, 

judging by the presence of the ammonites Valdedorsellat, Parasite site s, and Lemuroceras (Subarcthoplites) is not younger than early Albian.
CRETACEOUS AMMONITES FROM CHITINA VALLEY AND TALKEETNA MOUNTAINS 95

534624 O 6
96 SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY

TABLE 2. Localities at which ammonites were collected from the Albian strata of the Chitina Valley and the Talkeetna Mountains

Locality on 

figs. 2 and 3

!_-_.___

2

3_-_____

3

3_______

3_______

3 _____

4

4_._____

5

6_._____

6_-_____

?-______

7

7-_____

7

7_._____

8_---_-_

8_______

8-______

9_______

10______

10______

!!-_____

12______

12_____

12

13______

14______

15______

16______

17

18______

19______

21_____

20______

Geological Survey Mesozoic 

localities

9950

14477

8873

8875

8876

14484

1 448^

9971

14487

14471

9976

QQ7S

9147

2191

2201

9966

9967

QQfi7«

2173

9972

QQ73

8872

8877

8878

8880

14466

14467

14468

11389

6313

14514

9480

Q4Q2

Q48Q

24877

25320

25329

Collectors' field 

Nos.

32

AM-F14

K7

60

61

28AM-F21

OCATVT T?OO

28AM-F24

AM-F8

^Q

61

1048

K

Kfl

Kfl

6

KK

KK

KK

62

63

«K

28AM-F4

28AM-F4a

28AM-F5

10

g

28AM-F51

14

04

 }-[

53AGzl37

K4 A ri 7 cq

54AGz56L

Collector, year of collections, description of locality, and lithologic features

Moffit, F. H., 1916. On west side of Trail Creek at altitude of 3,500 ft, Chitina Valley.

Moffit, F. H., 1928. Near head of Chokosna River, 1 mile up southern tributary that joins

river at the Kuskulana Trail, Chitina Valley. 

Martin, G. C., and Overbeck, R. M., 1914. East bank of Fohlin Creek, 4,900 ft north of

mouth of Bear Creek, Chitina Valley. 

Martin, G. C., and Overbeck, R. M., 1914. East bank of Fohlin Creek about 6,800 ft

north of Bear Creek, Chitina Valley. 

Martin, G. C., and Overbeck, R. M., 1914. East bank of Fohlin Creek 5,500 ft north of

Bear Creek, Chitina Valley. 

Moffit, F. H., 1928. Fohlin Creek 1 mile north of Bear Creek. Near Mes. loc. 8873,

Chitina Valley. 

Moffit, F. H., 1928. Fohlin Creek 100 yds north of Mes. loc. 14484, Chitina Valley.

Moffit, F. H., 1916. At falls on first northern tributary of Bear Creek at altitude of 3,200

ft and a little more than 1 mile from Bear Creek, Chitina Valley. 

Moffit, F. H., 1928. First northern tributary of Bear Creek, 1 mile above its mouth, Chitina

Valley. 

Moffit, F. H., 1928. About 1}_ miles north of Bear Creek and the same distance east of

Fohlin Creek, Chitina Valley. 

Moffit, F. H., 1916. On Fohlin Creek 125 ft above mouth of Bear Creek, Chitina Valley.

Moffit, F. H., 1916. On Fohlin Creek, 1,300 ft upstream from Mes. loc. 9976, Chitina

Valley.

12, Chitina Valley. 

Schrader, F. C., and Spencer, A. C., 1900. Creek tributary to the Lakina River half a mile

above crossing of old trail between Lakina and Kennicott Rivers, Chitina Valley. 

Schrader, F. C., and Spencer, A. C., 1900. Old trail between Lakina and Kennicott Rivers,

Chitina Valley. 

Moffit, F. H., 1916. Half a mile above mouth of Bear Creek on first tributary from north,

Chitina Valley. 

Moffit, F. H., 1916. A little upstream from Mes. loc. 9966, Chitina Valley.

Moffit, F. H., 1916. Float from Mes. loc. 9967, Chitina Valley.

Valley. 

Moffit, F. H., 1916. On Bear Creek at altitude of 2,850 ft about half way from Fohlin

Creek to Fourth of July Pass. Soft, gray sandstone containing nodular masses, Chitina 

Valley. 

Moffit, F. H., 1916. On Bear Creek near Mes. loc. 9972, Chitina Valley.

Martin, G. C., and Overbeck, R. M., 1914. Float in Bear Creek about 2}£ miles above its

mouth, Chitina Valley. 

Martin, G. C., and Overbeck, R. M., 1914. Bear Creek about 3 miles above mouth, Chitina

Valley. 

Martin, G. C., and Overbeck, R. M., 1914. 100 yds above Mes. loc. 8877 on Bear Creek,

Chitina Valley. 

Martin, G. C., and Overbeck, R. M., 1914. Bear Creek about 400 ft below summit of Fourth

of July Pass, Chitina Valley. 

Moffit, F. H., 1928. Northern tributary of Fourth of July Creek \% miles from its mouth,

Chitina Valley. 

Moffit, F. H., 1928. Same as Mes. loc. 14466.

Moffit, F. H., 1928. Near Mes. loc. 14466, Chitina Valley.

Moffit, F. H., 1922. On Fourth of July Creek 2 miles from Kennicott Glacier, Chitina

Valley.

Moffit, F. H., 1928. West side of Nizina Glacier 1 mile from its lower end. Chitina Valley.

Creek, Chitina Valley.

north side of Young Creek west of big bend at altitude of 3,450 ft and half a mile above 

foot of trail to the Chitina River, Chitina Valley. 

Moffit, F. H., and Overbeck, R. M., 1915. From nodules in sandstone near south end of

trail from Chitina Valley to Young Creek at altitude of 1,900 ft, Chitina Valley.

overlying the Nelchina limestone near head of Billy Creek, Talkeetna Mts. (A-2) quad., 

lat 62°01'40J_" N., long 147°39'18" W., Talkeetna Mts.

the Nelchina limestone near the head of Flume Creek. Talkeetna Mts. (A-2) quad, 

lat 62°00'41" N., long 147°34'46" W., Talkeetna Mts.

the Nelchina limestone near the head of Flume Creek. Talkeetna Mts. (A-2) quad., 

lat 62°00'41" N., to lat 62°00'43" N., long 147°34'46" W., to long 147°34'54" W., 

Talkeetna Mts.
CRETACEOUS AMMONITES

148° 20' 148'

FROM CHITINA VALLEY AND TALKEETNA MOUNTAINS

00' 40' 147° 20'

97

62° 00'

FIGURE 24. Index map showing Albian localities in the Talkeetna Mountains.

The faimule characterized by Freboldiceras singulars Imlay contains Albian ammonites that are unlike 

those in the Chitina Valley or in California, but are 

identical with or closely similar to species in the western interior of Canada. The faunule is correlated 

with beds in Canada that overlie the zone of Lemiiroceras belli and underlie the zone of Gastroplites kingi. 

but the evidence is not conclusive. If this correlation 

is correct, it is probably younger than the Brewericeras breweri faunule in the Chitina Valley on the 

basis that that faunule contains a species of Lemuroceras that occurs in the zone of Lemuroceras 'belli in 

northern Alaska.

Other ammonite faunules of late Albian age are 

possibly represented in the Chitina Valley at certain 

localities near the base of Nizina Glacier and near the 

mouth of Canyon Creek. The collections on hand, 

however, contain only long-ranging species that could 

be of Cenomanian age.

The Albian ammonites from the Chitina Valley belong to the same faunal province as the Albian ammonites of California and Oregon as shown by the 

presence of the genera Brewericeras, Hulenites, Puzosigella, and Leconteites. A possible connection with 

the boreal province is indicated, however, by the presence of Lemuroceras (Su'barcthoplites) and Callizoniceras. In contrast the Albian ammonites from the 

Talkeetna Mountains belong to the same faunal 

province as those in the western interior of Canada and 

in northern Alaska. It appears, therefore, that the 

Albian sea that covered the areas now occupied by 

the Chitina Valley and Talkeetna Mountains had 

broad connections with the seas in the western interior 

of the continent and in California. Careful stratigraphic collecting from the Albian beds in the Chitina 

Valley would probably furnish the evidence for precise interregional correlations.

SYSTEMATIC DESCRIPTIONS

Class CEPHALOPODA 

Genus PHYLLOPACHYCERAS Spath, 1925

Phyllopachyceras chitinanum Imlay, n. sp. 

Plate 11, figures 1-5

This species is represented only by the holotype. 

Whorls ovate in section, a little higher than wide, 

widest near middle of flanks, becoming stouter during 

growth. Flanks gently convex, rounding evenly into 

umbilical wall and into arched venter. Umbilicus extremely narrow. Body chamber occupies three-fifths 

of a whorl and appears to be nearly complete.
98 SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY

TABLE 3. Geographic distribution of early Albian ammonites from the Chitina Valley and Talkeetna Mountains, Alaska 

[Numbers 1-21 refer to numbers on figs. 23 and 24. Higher numbers are Geological Survey Mesozoic locality numbers]

Arcthoplites? sp

Chitina Valley

Kennicott formation

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The ornamentation on the adapical part of the body 

whorl consists of nearly microscopic raised lines. 

These are replaced adorally at a diameter of about 31 

mm by low rounded ribs on the venter. Toward the 

aperture the ribs become stronger and originate at 

various heights on the middle and upper parts of the 

flanks. All ribs are of equal strength on the venter 

which they cross nearly transversely. The suture line 

has the tetraphyllic first and second lateral saddles that 

are typical in the genus.

The holotype has a maximum diameter of 38 mm. 

At a diameter of 35 mm, it has a whorl height of 22 mm 

and a whorl thickness of 21 mm. At the adapical end 

of the body chamber, the whorl height is 13 mm, and 

the whorl thickness is 10.5 mm.

This species compared with PhyHopachyceras tlieresae (Anderson) (1938, p. 141, pi. 12, figs. 4, 5) from 

California has a stouter whorl section, a smaller umbilicus, and finer, denser ribbing. It is particularly characterized by its stout whorl section.

Type: Holotype USNM 130142. 

Locality: USGS Mes. loc. 9492.

Genus HYPOPHYLLOCERAS Salfeld, 1924

Hypophylloceras cf. H. californicum (Anderson)

Plate 11, figure 29

One laterally crushed septate specimen bears ribbing 

similar to that on H. californicum (Anderson) (1938, 

p. 143, pi. 12, fig. 7), but the characteristics of that 

species are not known sufficiently to permit identification. H. onoense (Stanton) (1896, p. 76; Anderson, 

1928, p. 142, pi. 11, figs. 1, 2) has much finer ribbing.

Figured specimen: USNM 130132. 

Locality: USGS Mes. loc. 9492.
CRETACEOUS AMMONITES FROM CHITINA VALLEY AND TALKEETNA MOUNTAINS 99

Genus CALLIPHYLLOCERAS Spath, 1927

Calliphylloceras nizinanum Imlay, n. sp.

Plate 11, figures 6-12

This species is represented by 20 specimens, of which 

most are small and septate. Whorls ovate in section, 

higher than wide, highly involute. Flanks gently convex, converging above to a rather narrowly rounded 

venter. Umbilicus extremely narrow; wall steep. 

Body chamber represented by three-fourths of a whorl.

Surface of shell covered with very fine striae that 

incline forward on the flanks in a gently flexous manner and arch forward on the venter. Surface of mold 

marked by sigmoidal constrictions that are barely evident at a diameter of 25 mm, but become fairly strong 

adorally, and arch forward on the venter. Six constrictions are present on the body chamber. Fine lirae 

are visible only on the venter. The suture line is 

typical of the genus.

The small paratype shown on plate 11, figures 10 

and 11, at a diameter of 33 mm, has a wT horl height 

of 19 mm, a whorl thickness of 15 mm, and an umbilical width of 3 mm. On the holotype at a diameter 

of 46 mm, the corresponding dimensions are 30, 21, 

and 4 mm.

This species is distinguished from C. aldersoni 

(Anderson) (1938, p. 143, pi. 11, figs. 3-6) by its constrictions and growth striae arching forward more 

strongly on the venter, by lacking flexuous raised lines 

on the flanks, and by having a higher wT horl section.

Types: Holotype USNM 130138. Paratype USNM 130139- 

Locality: USGS Mes. loc. 9492.

Calliphylloceras cf. C. aldersoni (Anderson) 

Plate 11, figs. 13-17

Three specimens very closely resemble C. aldersoni 

(Anderson) (1938, p. 143, pi. 11, figs. 3-6) from California as far as their preservation and small size permit comparison. Their flanks converge rapidly toward 

a narrowly rounded venter and are covered with fine 

flexuous raised lines that arch forward gently on the 

venter, and the internal molds bear five flexuous constrictions.

Figured specimen: USNM 130161. 

Locality: USGS Mes. loc. 9972.

Genus ANAGAITDRYCERAS Shimizu, 1934

Anagaudryceras aurarium (Anderson)

Plate 11, figures 18, 19, 24

Lutoccras (Kossmatellal) aurarium Anderson, 1938, Geol. Soc. 

America Spec. Paper 16, p. 151, pi. 20, figs. 1, 2.

This species is represented in the Chitina Valley by 

28 specimens that agree very well with the original

description and illustrations by Anderson except for 

the presence of very fine, forwardly inclined regularly 

spaced lirae. These are visible only on a few specimens 

in places where some of the shell is preserved.

Type: Plesiotype USNM 130154.

Localities: USGS Mes. Iocs. 2201, SS73, 9971, 14484, 14485. 

Fragments possibly belonging to this species occur at Mes. Iocs. 

8880, 9489, 9950, 9966.

Genus KOSSMATELLA Jacob, 1907

Kossmatella cappsi Imlay, n. sp.

Plate 12, figures 17-22

Three specimens of this species are on hand. Whorls 

in young stages depressed ovate and much wider than 

high, in adult specimens becoming subquadrate and 

higher than wide, embracing preceding whorls about 

two-fifths. Flanks on inner whorls strongly convex, 

rounding evenly into nearly vertical umbilical wall 

and into broadly rounded venter. Flanks on adult 

body chamber somewhat flattened, rounding fairly 

rapidly into steep umbilical wall and into moderately 

arched venter. Umbilicus moderate in width, wall 

steeply inclined to nearly vertical. Body chamber incomplete, represented by slightly more than half a 

whorl.

The entire surface of the shell is covered with fine 

forwardly inclined lines. In addition both shell and 

mold are marked by regular forwardly inclined constrictions that are most pronounced on the inner whorls 

and near the aperture of the adult body chamber. The 

constrictions on the inner whorls demarcate prominent 

lateral bulges that become much less prominent 

adorally on the penultimate whorl. The adult body 

whorl has 15 constrictions.

The suture line has fairly symmetrical bifid saddles 

and a bifid first lateral lobe.

At a diameter of 63 mm, the largest specimen from 

Alaska has a whorl height of 29 mm, a whorl thickness 

of 25 mm, and an umbilical width of 20 mm. At a 

diameter of 58 mm the same measurements are 25, 22, 

and 17 mm respectively.

The Alaskan specimens in general appearance are 

similar to Kossmatella agassizianum (Pictet) as figured by Jacob (1908, pi. 2, figs. 8-10) and differ mainly 

by having much weaker bulges and by their constrictions inclining adapically near the umbilicus. They 

show even greater resemblance to Kossmatella'gainesi 

(Anderson) (1938, p. 153, pi. 20, figs. 3-5) from California, from which they differ by the presence of 

lateral bulges on their inner whorls and by fewer constrictions.
100 SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY

The species is named in honor of S. R. Capps in 

recognition of many years of study of Alaskan geology.

Types: Holotype USNM 130160. Parataypes USNM 130140. 

Localities: USGS Mes. Iocs. 9492, 14514.

Genus TETRAGONITES Kossmat, 1895

Tetragonites aff. T. timotheanus (Pictet)

Plate 12, figures 24-28

Some Alaskan specimens of this genus differ from 

T. timotheanus (Pictet) (in Pictet and Koux, 1847, 

p. 39, pi. 2, figs. 6a-b, pi. 3, figs, la-c) by having 

parallel, instead of convergent flanks. They have been 

described in detail by Matsumoto (1959, p. 77-79, pi. 

22, figs, la-c, 2a-c) in a paper dealing mainly with 

Cenomanian ammonites from the upper part of the 

Chitina Valley. In that paper most of the occurrences 

listed are from localities of late Albian to Cenomanian 

age, but Mesozoic locality 9492, which is either of early 

Albian or early middle Albian age, is also included. 

The spacimens figured herein are all from Mesozoic 

locality 9492.

Figured specimen: USNM 130131.

Genus PTYCHOCERAS d'Orbigny, 1842

Ptychoceras of. P. laeve (Gabb)

Plate 12, figure 23

Two small internal molds show parts of two closely 

appressed limbs that belong mostly to the body chamber. The smaller limb is much depressed. The larger 

limb is nearly circular in section. The surface is nearly 

smooth, being marked only by faint growth lines and 

by several constrictions. The constrictions near the 

adoral end of the larger limb are bordered by a 

rounded rib that is most prominent on the venter.

These specimens differ from P. laeve (Gabb) (1869, 

p. 144, pi. 25, figs. 21, 21a, b) in being much smaller, 

but possibly belong to that species.

Figured specimen: USNM 130163. 

Localities: USGS Mes. Iocs. 8872, 9972.

Genus VALDEDORSELLA Breistroffer, 1947

Valdedorsella ? whiteavesi Imlay, n. sp.

Plate 11, figures 20-23, 25-28

?Ammonites (sp. undet.). Whiteaves, 1876, Geol. Survey 

Canada Mesozoic Fossils, v. 1, p. 47, pi. 3, figs. 4, 4a.

Two small ammonites from the Chitina Valley 

greatly resemble a small ammonite from the Queen 

Charlotte Islands described by Whiteaves (1876, p. 47, 

pi. 3, figs. 4, 4a) and are possibly identical. They have 

in common a broadly rounded, depressed whorl section, 

a small deep umbilicus, a rounded umbilical margin,

and 6 or 7 sigmoidal constrictions that arch forward 

on the venter. On the specimens from the Chitina 

Valley, each constriction is posteriorly bordered by a 

low rounded rib that is slightly swollen at the umbilical margin. Also, a few weaker riblets occur on the 

venter between the constrictions.

The suture line is rather simple. Its saddles are 

slender and bifid; its first lateral lobe is trifid and 

slightly shorter than the ventral lobe; and its auxiliaries descend regularly to the umbilicus.

The holotype at a maximum diameter of 11.5 mm has 

a whorl height of 6.5 mm, a whorl thickness of 8.5 mm, 

and an umbilical width of 2 mm.

Except for a broader whorl section VA whiteavesi 

Imlay, n. sp. greatly resembles V. getulina (Coquand) 

as illustrated by Pervinquiere (1907, p. 154, pi. 6, figs. 

16a-c) from beds near the Aptian-Albian boundary in 

Tunisia. V. hourcqi (Collingnon) (1937, p. 18, pi. 2, 

figs. 6, 6a, b, 7, 7a, b) from Madagascar is less depressed and has stronger ribbing and wider saddles, 

and its constrictions cross the venter nearly transversely instead of arching forward. V. akuschaensis 

(Anthula) (1899, p. 104, pi. 8, figs. 3a-c) from the 

Caucasus is more compressed and has wider saddles, 

but is difficult to compare because of its larger size.

The specimens from the Chitina Valley show some 

resemblances also to the upper Albian Puzosia chirichensis Pervinquiere (1907, p. 152, pi. 6, figs. 17-20), 

which species Breistroffer (1947, p. 60) assigns to 

Lunatodorsella, a subgenus of Desmoceras. That subgenus is distinguished, however, by a craterlike umbilicus, a rather sharp umbilical edge, and straighter constrictions.

The range of Valdedorsella, according to Wright 

(1956, L363), is Hauterivian to Aptian. Collignon 

(1937, p. 19) notes that V. getulina, (Coquand) exists 

in both the Barremian and the Aptian of the Mediterranean region, but predominates in the Aptian. He 

notes that V, akuschaensis (Anthula) occurs in Aptian 

beds in the Caucasus and above the Aptian in the Clansayes beds in the province of Drome in southern 

France.

This occurrence in the Clansayes beds is interesting 

because it indicates that the genus Valdedorsella ranges 

at least as high as the Aptian-Albian boundary. 

Whether the Clansayes beds are placed at the top of 

the Aptian (Breistroffer, 1947, p. 11-20) or at the base 

of the Albian (Spath, 1941, p. 668; Collignon, 1949, p. 

109), they are not much older than the beds in the 

Chitina Valley, Alaska, that contain the lower Albian 

ammonites herein described.

Types: Holotype USNM 130145. Paratype USNM 130146. 

Locality: USGS Mes. loc. 9492.
CRETACEOUS AMMONITES FROM CHITINA VALLEY AND TALKEETNA MOUNTAINS 101

Genus CALLIZONICERAS Spath, 1923 

Subgenus WOLLEMANNICERAS Breistroffer, 1947

Callizoniceras (Wollemanniceras) alaskanum Imlay, n. sp. 

Plate 12, figures 11-16

The species is represented by six specimens. The 

holotype has been laterally crushed at the adapical 

end of the body whorl and slightly depressed at the 

adoral end. Shell small, moderately compressed. 

Whorls ovate depressed, becoming less depressed 

adorally, embracing about one-half of preceding 

whorls. Flanks convex, rounding evenly into broadly 

arched venter and into umbilical wall. Umbilicus 

moderate in width; wall steeply inclined at base. 

Body chamber on holotype is represented by threefifths of a whorl and appears to be nearly complete.

The ornamentation consists partly of gently flexous, 

rounded ribs of moderate strength that tend to fade on 

the venter. It includes some rather strongly flexuous, 

pronounced constrictions that arch forward on the 

venter and are bordered by flared ribs that are particularly prominent on the venter. The primary ribs begin 

low on the umbilical wall and incline forward to near 

the middle of the flanks where about half of them bifurcate. A few primary ribs bifurcate considerably 

below the middle of the flanks. All ribs, forked and 

single, curve forward strongly on the upper parts of 

the flanks, arch forward on the venter, and weaken 

ventrally. On the paratypes the ribs do not quite fade 

out on the venter. On the holotype the venter of the 

body chamber is nearly smooth except near the aperture where the ribbing becomes a little stronger. 

Tubercles are not present. Seven to eight constrictions 

occur on each whorl. The suture line is too poorly 

preserved to be traced.

The paratype (pi. 12, figs. 13, 14) at a diameter of 

23 mm has a whorl height of 9 mm, a whorl thickness 

of 11 mm, and an umbilical width of 6.5 mm. The 

holotype has a more compressed whorl section but has 

been somewhat deformed.

This species has the general appearance of CalUsoniceras (Wollemanniceras) keilliacki Wollemann (1907, 

p. 36, pi. 5, figs. 4, 4a, 5, 5a; Casey, 1957, pi. 7, figs. 

4, 4a, 5). It differs by having a more depressed whorl 

section, less flexuous constrictions and ribs, a greater 

number of forked ribs, and perhaps denser ribbing.

Types: Holotype USNM 130165. Paratypes USNM 130166a, b. 

Localities: USGS Mes. Iocs. 8873, 9976.

Callizoniceras (Wollemanniceras) fohlinense Imlay, n. sp. 

Plate 12, figures 1-10

The species is represented by five specimens. Shell 

small, compressed. Whorls subquadrate, a little higher

than wide, embracing about one-half. Flanks gently 

convex on inner whorls, becoming flattened during 

growth. Venter highly arched. Umbilicus moderate 

in width, shallow; wall low, steeply inclined on inner 

whorls, becoming vertical on outer whorls; umbilical 

edge evenly rounded on inner whorls, abruptly rounded 

on outer whorl. Body chamber unknown.

The ornamentation consists of thick, gently flexuous 

ribs and constrictions that incline forward on the 

flanks, arch forward strongly on the venter, and become progressively stronger and more flexuous during 

growth. On the smaller whorls (pi. 12, fig. 6) the 

ornamentation consists of variably spaced unbranched 

ribs that begin low on the umbilical wall, are strong on 

the flanks, and nearly disappear on the venter. At a 

diameter of about 13 mm some short ribs are intercalated high on the flanks. At greater diameters many 

ribs branch near the middle of the flanks, others are 

indistinctly connected with secondary ribs, and a few 

remain unbranched. The ribs and constrictions on the 

venter are much weaker than on the flanks at all stages 

of growth, but become a little stronger during growth. 

Generally the ribs bordering the constrictions on the 

venter are a little stronger than the other ribs.

The suture line is simple. The auxiliaries do not 

descend toward the umbilicus as in Callizoniceras 

(Wollemanniceras) keilhacki Wollemann (1907, pi. 5, 

fig. 5a), but rather trend radially as in C. hoyeri (Von 

Koenen) (1902, pi. 38, fig. 6c). '

The holotype at a diameter of 27 mm has a whorl 

height of 10.7 mm, a whorl thickness of 9.5 mm, and 

an umbilical width of 8 mm.

This species compared with C. alaskanum Imlay, n. 

sp., has a subquadrate rather than a depressed ovate 

whorl section and has stronger more flexuous ribs. It 

bears much greater resemblance to the paratype of 

C. Jceilhacki (Wollemann) (1907, pi. 5, figs. 4a, 4b), 

but appears to have more forked ribs and a less 

rounded whorl section.

Types: Holotype USNM 130155. Paratypes USNM 130156. 

Locality: USGS Mes. Inc. 14484.

Genus MOFFITITES Imlay, 1959 

The original description of this genus is as follows:

This genus is characterized by an inflated shell, moderate involution, a whorl section that changes from ovate to coronate 

during growth, by flexuous ribs and constrictions that arch 

forward strongly on the venter, by frequent bifurcation of the 

primary ribs into somewhat weaker secondary ribs near the 

middle of the flanks, by a tendency of the secondary ribs to 

weaken and become striate as they near the middle of the 

venter, by the occurrence of flared ribs adjacent to the constrictions, and by having a desmoceratid suture line whose 

auxiliaries descend gradually toward the umbilical seam.
102 SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY

It differs from the new genus Kennicottia with which it is 

associated by being much more inflated, by having much 

stronger primary ribs, and by a tendency of its secondary ribs 

to become striate on the venter. Its ornamentation bears some 

resemblance to that of Pseudoliaploceras Hyatt (1900, p. 500), 

but it is easily distinguished by having regularly furcating 

ribs and a coronate whorl section. It resembles ValdedorseUa 

Breistroffer (1947, p. 60) in shape and involution, but the differentiation of its ribs into primaries and secondaries and the 

considerable strength of its primary ribs permit easy separation of the genera. The same features distinguish it readily 

from genera within the Holcodiscidae such as Astieridiscus 

Kilian (1910, p. 265).

The type species of Moffitites is Moffitites robust us Imlay, n. 

sp.

This genus is named for Fred H. Moffit in recognition of his 

many important contributions to Alaskan geology as a member 

of the U.S. Geological Survey.

Moffitites robustus Imlay 

Plate 13, figures 1-13

Moffitites robustus Imlay, 1959, Jour. Paleontology, v. 33, no. 1, 

p. 181-182, pi. 29, figs. 9-14.

The original description follows:

The species is represented by 30 specimens. Shell stout, 

moderate in size. Whorls ovate depressed, becoming stouter 

during growth, embracing about three-fifths. Flanks gently 

convex on immature specimens, becoming highly convex on 

adults. Venter highly arched in immature specimens, becoming broadly rounded on adults. Umbilicus moderate in 

width; wall inclined steeply, fairly high, Founding evenly into 

flanks. Body chamber incomplete, but represented by at least 

half a whorl.

The ribbing is gently fiexuous on the flanks, is arched forward on the venter, and is variable in density. The primary 

ribs are moderate in strength, are triangular in section, become 

stronger ventrally, and are generally narrower than the interspaces. They begin low on the umbilical wall, incline forward 

slightly on the wall and on the lower third of the flanks, and 

then recurve gently near the middle of the flanks where they 

pass into, or are replaced by much weaker secondary ribs.

On immature specimens some of the primary ribs bifurcate 

near the middle of the flanks. Others remain single on the 

flanks, but may be separated from each other, or from forked 

ribs by 1 or 2 secondary ribs that arise freely on the upper 

parts of the flanks. On the penultimate and body whorls most 

of the primary ribs bifurcate near the middle of the flanks and 

many of the pairs of secondary ribs are separated on the 

venter by 1 or 2 intercalated ribs. In many specimens the secondary ribs tend to weaken and become striate along the midventral area, but this tendency varies considerably from one 

specimen to another and from whorl to whorl. Tubercles are 

not present at any growth stage.

All whorls are marked by 6 to 8 constrictions that are fiexuous on the flanks and arch forward on the venters. The constrictions are inconspicuous on the immature whorls, but become more pronounced adorally. On the outer whorls the constrictions are generally bounded by 1 or 2 swollen primary ribs 

on the flanks and by a forwardly projected swelling on the 

venter.

The suture line is desmoceratid in plan. Its auxiliaries descend gradually toward the umbilical seam as in Desmoceras, 

Pseudohaploceras or Valdedorsella.

The holotype at a diameter of 97 mm has a whorl height of 

43 mm, a whorl thickness of 52 mm, and an umbilical width of 

31 mm. At a diameter of 66 mm the other dimensions are 30, 

40, and 20 mm respectively. On paratype USNM 129875b at a 

diameter of 56 mm the other dimensions are 24, 37, and 18 mm 

respectively.

Types: Holotype USNM 129874. Paratypes USNM 129875a, 

b, 129876a, b.

Occurrence: USGS Mes. Iocs. 2147, 2191, 8873, 8875, 8876, 

8878, 9489, 9976a, 9978, 14471, 14484, 14485. Fragments that 

possibly belong to this species occur at Mes. loc. 2173, 9971, 

and 14467.

Moffitites crassus Imlay, n. sp.

Plate 14, figures 3-7

This species is represented by three specimens. It 

differs from Moffitites robustus Imlay, n. sp., by having 

a somewhat less depressed whorl section, much sparser, 

coarser ribbing, and fewer intercalated ribs on the 

upper part of the flanks, and the secondary ribs do not 

become striate on the venter. The holotype has 26 

primary ribs and only 2 secondary ribs for each primary. Specimens of M. robustus Imlay at a comparable size have from 33 to 35 primary ribs and a 

little more than 2 secondary ribs for each primary.

The holotype at a diameter of 35.5 mm has a whorl 

height of 16.5 mm, a whorl thickness of 16.5 mm, and 

an umbilical width of 8.5 mm. The suture line is not 

preserved.

Types: Holotype USNM 130175. Paratype USNM 130176. 

Localities: USGS Mes. Iocs. 8878, 14477, 14487.

Genus FREBOLDICERAS Imlay, 1959

The original description is as follows:

This genus resembles Callizoniceras Spath (1923, p. 35) from 

the upper Barremian to lower Albian of Europe (Von Koenen, 

1902, p. 58, pi. 9, figs. 5a-c, p. 60, pi. 28, figs. 5a, b, 6a-c, 7; 

Wollemann, 1907, p. 36, pi. 5, figs. 4, 4a, 5, 5a; Brinkman, 1937, 

p. 8-10, figs. 4, 5). It differs by being more involute; by its 

whorl section being higher and more narrowly rounded; by its 

primary ribs being more regularly-spaced, more swollen, and 

confined generally to the lower part of the flanks; by its constrictions being less regularly-spaced; and by having fewer secondary ribs. Its smooth body chamber and large size may be 

other distinctions. Its suture is very simple and closely resembles that of Callizoniceras. The type species of Freboldiceras is Freboldiceras singulare Imlay, n. sp.

Freboldiceras singulare Imlay 

Plate 14, figures 8-17

Freboldiceras singulare Imlay, 1959, Jour. Paleontology, v. 33, 

no. 1, p. 182, 183, pi. 30, figs. 1-7.

The original description is as followT s:

Four specimens of this species have been found in the Talkeetna Mountains at one locality. Shell compressed, discoidal.
CRETACEOUS AMMONITES FROM CHITINA VALLEY AND TALKEETNA MOUNTAINS 103

Whorls subovate in section, considerably higher than wide, 

thickest near umbilicus, embracing about two-thirds. Flanks 

gently convex in their lower parts, but tapering above to a 

narrowly rounded venter. Umbilicus fairly narrow, wall 

steeply inclined, rounding evenly into flanks. Body chamber 

represented by at least three-fifths of a whorl.

The ornamentation of the septate parts of the shell consist 

mostly of prominent, flexuous, regularly-spaced primary ribs, 

of deep, irregularly-spaced constrictions, and of flexuous striae. 

The primary ribs begin high on the umbilical wall, incline forward and become swollen near the umbilical edge, and then 

curve forward near the middle of the flanks where most of 

thern pass into bundles of striae that arch forward gently on 

the flanks and venter. The primary ribs that adjoin constrictions continue across the flanks and venter, but are more prominent on the internal mold than on the shell. Some specimens 

at a few places have single, short secondary ribs that are intercalated between the primary ribs and continue across the 

venter. Where shelly material is preserved its surface is covered with fine, flexuous striae that is coarser on the primary 

ribs than on the interspaces. The periphery of the internal 

mold is strongly undulating. Wherever the shell is preserved 

the periphery is nearly smooth.

The adult body chamber is nearly smooth. Faint flexuous 

striae are present in a few places where shell layers are present. On the penultimate whorl the primary ribs become much 

weaker adorally and are barely visible near the last-formed 

septa.

The suture-line is very simple. It greatly resembles that of 

the genus CalUzoniccms (Wollemann, 1907, pi. 5, fig. 5a; V. 

Koenen, 1902, pi. 9, fig. 5c, pi. 38, figs. 6, 7; Chaput, 1920, pi. 1, 

figs. 4a, b) in its broad first lateral saddle, in its first lateral 

lobe being slightly deeper than the ventral lobe, and in its 

auxiliary saddles not being retracted adapically near the umbilicus. In fact the auxiliaries ascend slightly as they approach 

the umbilical seam.

The holotype at a diameter of 55 mm, has a whorl height of 

24 mm, a whorl thickness of 19 mm and an umbilical width of 

14 mm.

This species resembles Lemiiroceras irenense McLearn (1945, 

pi. 5, fig. 5, 1948, p. 2) from the Moosebar formation of British 

Columbia, and probably belongs in the same genus. The preservation of the holotype of L. irenenfte is not sufficient, however, 

to prove whether the resemblances are accidental or reflect 

generic relationships.

Types: Holotype USN 129868. USNM 129869a-c. 

Occurrence: USGS Mes. loc. 24877.

Genus KENNICOTTIA Imlay, 1959 

The original description is as follows:

This genus is characterized by being fairly involute, by the 

presence of persistent primary ribs that bifurcate fairly regularly near the middle of the flanks, by having flexuous ribs and 

constrictions that arch forward strongly on the venter, by the 

presence of some flared ribs adjoining the constrictions, by reduction of the secondary ribs along the midline of the venter, 

and by its suture line having regularly descending auxiliary 

lobes. It shows resemblance to PseudoJiaploceras Hyatt (1900, 

p. 570) in amount of involution, whorl shape, suture-line, presence of flexuous constrictions and ribs, and presence of bifurcating ribs. It differs, however, by having a more subquadrate 

whorl section, a vertical umbilical wall, flatter flanks, weaker

constrictions and flared ribs, and stronger, more regularly bifurcating primary ribs. It differs from Yahledorsella (Briestroffer, 1947, p. (JO) in its whorl section being subquadrate instead of round and by the presence of bifurcating ribs. It 

differs from Puzosiu by being considerably more involute, by 

the presence of bifurcating primary ribs, and by the auxiliary 

lobes of its suture line descending regularly instead of abruptly. 

The type species of Kennicottia is Kennicottia bifurcata Imlay, n. sp.

Kennicottia Mfureata Imlay

Plate 15, figures 1-6

Kennicottia bifiircata Imlay, 1959, Jour. Paleontology, v. 33, 

n. 1. p. 183, 184, pi. 30, figs. 8-13.

The original description is as follows:

This species is represented by 13 specimens. Whorls subovate in immature specimens, becoming subquadrate in adult, 

embracing about three-fifths. Flanks gently convex, becoming 

less so during growth, rounding into highly arched venter. 

Umbilicus fairly narrow; wall low, vertical at base, rounding 

evenly into flanks. Body chamber unknown.

The ribbing is gently flexuous on the flanks and arched forward strongly on the venter. The primary ribs are somewhat 

stronger than the secondary ribs. They begin low on the 

umbilical wall, are highest on the edge of the wall and become 

rather broad ventrally. Most primary ribs bifurcate near the 

middle of the flanks, but some remain single, and some are 

indistinctly connected with secondary ribs. The secondary 

ribs are reduced in strength along the midline of the venter.

From 6 to 7 weak flexuous constrictions occur per whorl. 

They become more conspicuous adorally and are most conspicuous on the venter. On the adoral part of the holotype, 

they are bounded by swollen ribs.

The suture line is desmocerated in type. Its regularly descending auxiliary lobes contrast with the retracted auxiliaries 

in Puzosia, but are comparable with those in Pseudoliaploceras.

The holotype at a diameter of 63 mm has a whorl height of 

29 mm, a whorl thickness of 25 mm, and an umbilical width 

of 15 mm.

This species has a general resemblance to Pusosia subquadrata Anderson (1938, p. 186. pi. 45, figs. 3-5) from California, but differs by having much stronger primary ribs that 

bifurcate fairly regularly, by its ribbing being less flexuous, by 

its umbilical wall rounding more evenly into the flanks, and 

by its auxiliary lobes descending much more gradually toward 

the umbilical seam (compare Anderson, 1938, p. 183, text, fig. 3, 

no. 6).

Types: Holotype USNM 129870. Paratype USNM 129871. 

Occurrence: USGS Mes. Iocs. 8873, 9972, 14471, 14484.

Kennicottia rugosa Imlay, n. sp. 

Plate 15, figures 7-13

The species is represented by three specimens. Shell 

fairly large for genus, moderately compressed. Whorls 

subquadrate in section, becoming stouter during 

growth, embracing about three-fifths of preceding 

whorls. Flanks gently convex, becoming less so during growth, rounding evenly into broadly arched 

venter. Umbilicus fairly narrow; wall moderate in 

height, vertical at base, inclined above, and rounding
104 SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY

rather abruptly into flanks. Body chamber incomplete, 

but represented by at least half a whorl.

The ribbing is flexuous on the flanks, arched forward on the venter, and somewhat reduced in strength 

along the midventral lines. The primary ribs begin at 

the umbilical seam, and incline forward gently on the 

lower part of the flanks, and generally divide near the 

middle of the flanks into pairs of weaker secondary 

ribs that arch forward considerably. Some secondary ribs are indistinctly connected with the primary 

ribs, and some arise freely above the middle of the 

flanks.

About 8 to 9 flexnous constrictions occur on each 

whorl. These constrictions are inconspicuous on the 

smaller whorls, but become more prominent .during 

growth. Some constrictions on the penultimate and 

body whorls are bounded by swollen ribs that on the 

venter may become flared.

The suture line is poorly preserved and cannot be 

traced.

The holotype at its adoral end has a whorl height of 

58 mm and a whorl thickness of 51 mm. The paratype 

shown on plate 15, figures 7, 8, 11, at a diameter of 

42 mm, has a whorl height of 20.5 mm, a whorl thickness of 18 mm, and an umbilical width of 10 mm.

This species is distinguished from any species of 

Puzosia, by being more involute and by having persistent primary ribs of which most divide near the 

middle of the flanks. It differs from K. bifurcata Imlay, n. sp., by having a stouter whorl section, coarser, 

sparser ribbing, and a more abruptly rounded umbilical edge.

Types: Holotype USNM 130152. Paratypes USNM 130153a, b. 

Localities: USGS Mes. Iocs. 9489, 14485.

Genus PUZOSIA Bayle, 1878

Puzosia alaskana Imlay, n. sp.

Plate 16, figures 1-13

The species is represented by about 90 specimens. 

Whorls elliptical in section, higher than wide, widest 

near the umbilicus, embracing about one-half of preceding whorls. Flanks flattened, converging slightly 

toward the highly arched venter. Umbilicus moderate 

in width; wall steeply inclined in early growth stages, 

becoming vertical in adult, rounding evenly into flanks 

in early stages, but abruptly in adult. Body chamber 

represented by three-fifths of a whorl.

The ornamentation on immature specimens consists 

of strongly flexuous striae, riblets, and constrictions 

that arch forward considerably on the venter. They 

curve forward on the umbilical wall and base of the 

flanks, curve backward slightly below the middle of

the flanks, and then curve forward strongly on the 

upper part of the flanks. The riblets are most pronounced on the venter and upper parts of the flanks, 

but many of the constrictions are bounded on one, or 

on both, sides by riblets that begin at the umbilical 

margin. The constrictions number from 6 to 7 per 

whorl and are much more conspicuous on the internal 

molds than on the shell.

During growth the constrictions become more deeply 

impressed and more strongly arched on the venter. 

The ribbing weakens on the lower part of the flanks, 

but becomes stronger on the venter and on the upper 

part of the flanks. On the adult body chamber there 

are from 18 to 12 ribs between successive constrictions. 

Generally the ribs bordering the constrictions on the 

venter are somewhat swollen.

The suture line descends fairly rapidly toward the 

umbilicus. It is characterized by the second lateral 

saddle being a little higher than the first lateral 

saddle. This feature occurs in the genus Melchiorites 

as figured by Fallot (1920, p. 255-257) as well as in 

Puzosia (see Spath, 1923, pi. 2, fig. 3e).

The holotype at a diameter of 41 mm has a whorl 

height of 17 mm, a wT horl thickness of 13 mm, and an 

umbilical width of 13.5 mm. The same dimensions of 

the small paratype shown on plate 16, figure 11, are 

29, 12, 10, and 8.5 mm, respectively.

This species shows resemblances with the genera 

Melchiorites, Puzosia, and Hulenites. In lateral view 

it resembles Puzosia quenstedti Parona and Bonarelli 

(1897, p. 81, pi. 11, figs. 3a, b) from the Albian of 

Europe, but its ribs and constrictions arch forward 

much more on the venter, and it develops an abrupt 

instead of an evenly rounded umbilical edge. The pattern of its ornamentation and the shape of its umbilical edge is so similar to that of Hulenites reesidei 

(Anderson, 1938, p. 187, pi. 38, figs. 2, 3) from the late 

A.ptian to early Albian of California as to suggest that 

the two species are closely related. It may be distinguished from H. reesidei, however, by being more 

compressed, by having more projected ornamentation 

on the venter, by its ribs showing no tendency to fade 

on the venter, and by the ribs on the immature whorls 

being much finer and more flexuous. It also shows 

considerable resemblance to ribbed species of Melchiorites such as M. indigene.s Anderson (1938, p. 184, pi. 

67, fig. 3, pi. 68, fig. 2) from the Aptian of California, but it is distinguished by developing an abrupt 

umbilical edge and finer, denser, more sigmoidal ribbing.

Types: Holotype USNM 130143. Paratypes USNM 130144.

Locality: USGS Mes. loe. 9492.
CRETACEOUS AMMONITES FROM CHITINA VALLEY AND TALKEETNA MOUNTAINS 105

Genus BEUDANTICERAS Hitzel, 1905

Beudanticeras glabrum (Whiteaves)

Plate 16, figures 14-21

Placenticeras glabrum Whiteaves, 1889, Contr. to Canadian

Paleontology, v. 1, pt. 2, p. 172, pi. 24, figs. 1, la, b. 

Desnwceras affine var. glabrum Whiteaves, 1893, Royal Soc.

Canada, 1st ser., v. 10, p. 115, pi. 9. 

Beudanticeras glabrum (Whiteaves). McLearn, 1931, Royal

Soe. Canada, Trans., ser. 3, v. 25, sec. 4, p. 3. 

IBeudanticeras cf. B. glalirum Whiteaves. McLearn, 1945,

Geol. Survey Canada Paper 44-17 (2d ed.), pi. 4, figs.

2, 3. 

Beudanticeras glabmm (Whiteaves). Warren, 1947, Jour.

Paleontology, v. 21, p. 121, pi. 30, figs. 1-4.

Nine specimens of Beudanticeras, obtained in the Talkeetna Mountains, very closely resemble the original 

type specimen described by Whiteaves in their narrowly rounded whorl section, very narrow umbilicus, 

broad asymmetrical first lateral lobe, low, broad saddles, and numerous auxiliary lobes. Furthermore, five 

of the specimens are nearly as smooth as the type, being 

marked only by fine flexuous striae that are barely visible under oblique lighting. The other four differ from 

the type, however, by having riblets and wy eak bulges 

on the flanks. In addition several of the specimens 

bear one or more weak constrictions per whorl.

The presence of striae and. riblets on some of the 

specimens from the Talkeetna Mountains agrees with 

the observations of Warren (19-tT, p. 121) based on 

specimens of Beudanticeras glabrum (Whiteaves) from 

the Lowrer Mackenzie River valley in Canada. In his 

specimens, however, the ornamentation is most conspicuous near the umbilical border and constrictions 

are absent.

These differences are probably not of specific value 

considering that the number and strength of constrictions is a variable characteristic in many species of 

Beudanticeras, that the determination of the presence 

of weak constrictions may be difficult on poorly, preserved specimens, and that the distribution of riblets 

on the flanks may reflect individual variations. The 

fact that most of the specimens from the Talkeetna 

Mountains agree very well in their characteristics with 

the holotype of B. glabrum (Whiteaves) is herein 

given more weight than the minor differences in ornamentation mentioned above.

This species is characterized by its umbilicus being 

narrower and its saddles broader and lower than in 

most species that have been assigned to the genus 

Beudanticeras. The narrowness of the umbilicus is 

comparable, however, with that of B. Sutherlandi 

(Etheridge) (Whitehouse, 1928, p. 202, pi. 25, fig. -t) 

from Australia, which species differs from B. gla~brum 

by it^'stouter whorls. Furthermore the sutural pattern

is similar to that in B. laevigatum (J. cle C. Sowerby) 

(Spath, 1923, p. 56) from England; this species differs 

by its wider umbilicus and stouter whorls. Because of 

these similarities B. glabrum is herein considered as 

belonging within the range of variation of Beudanticeras, although possessing peculiar characteristics 

somewhat different from typical species of Beudanticeras in Europe. The differences are no greater than 

among certain Jurassic ammonites from western North 

America that Arkell (in Arkell and Playford, 1954, 

p. 596-597) assigns to genera based on European 

species even though they possess certain features that 

are not characteristic of the types.

Type: Plesiotypes USNM 130149. 

Locality: USGS Mes. loc. 24877.

Submenus GRANTZICERAS Imlay, 1960

Beudanticeras (Grantziceras) multiconstrictum Imlay

Plate 14, figures 1, 2

Beudanticeras (Grantziceras) muUiconstrictum Imlay, 1960, 

U.S. Geol. Survey Prof. Paper 335 (in press).

This species is characterized by many regularly 

spaced falciform constrictions, by broadly bundled 

striae on its flanks, and by a scaphitoid body chamber. 

Its largest specimens are considerably larger than any 

described European species of Beudanticeras, but are 

only about half as large as B. affine (Whiteaves) from 

Canada and northern Alaska. It resembles B. afjine 

more closely than any other described species of Beudanticeras. but differs by having nearly twice as many 

constrictions per whorl, a somewhat wider umbilicus, 

a shorter second lateral lobe, and a more compressed 

whorl section.

Type*: Holotype USNM 128721. Paratypes USNM 128722, 

128723.

Localities: USGS Mes. Iocs. 24877, 25320, 25329.

Genus BREWERICERAS Casey, 1954 

Brewericeras breweri (Gabb) 

Plate 17. figures 5-10, 12, 13

Ammonites breweri Gabb, 1864, Paleontology Calif, v. 1, p. 62,

pi. 10, fig. 7. 

Gabb, 1869. Gabb, Paleontology Calif., v. 2, p. 130, pi. 19,

fig. 5b. pi. 20, fig. 5. 

Gabb. Whiteaves, 1876, Geol. Survey Canada Mesozoic

Fossils, v. 1, p. 21, pi. 1, figs. 2, 2a, 3, 3a. 

Beudanticeras 'breweri (Gabb). Anderson. 1938, Geol. Soc.

America Spec. Paper 16, p. 189, pi. 43, fig. 3, pi. 44,

figs. 1, 2. 

Brewericeras breweri (Gabb). Casey, 1954. Washington Acad.

Sci. Jour., v. 44, no. 4, p. 112.

The 13 Alaskan specimens of this species on hand 

are all compressed, have flattened flanks, a highly 

arched venter, a vertical or nearly vertical umbilical
106 SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY

wall, and a fairly sharp umbilical rim. They all develop sigmoidal ribs that bear extremely weak, forwardly inclined swellings at the umbilical edge, that 

are prominent and sparse on the upper part of the 

flanks, and are reduced in strength on the venter and 

on the lower parts of the flanks. They show considerable variation, however, in strength of ribbing and in 

the stage of growth at which ribs first appear. In some 

specimens sigmoidal ribs appear at a diameter as small 

as 20 mm. In other specimens ribs first appear at a 

diameter of 50 mm. The costate parts of internal 

molds bear constrictions that are conspicuous only 

on the venter. The suture line is similar to that of 

the genus Beudanticeras.

Type: Plesiotype USNM 130133. 

Locality: USGS Mes. loc. 9492.

Brewericeras cf. B. hulenense (Anderson) 

Plate 17, figures 11, 14-16

Beudanticeras hulenense Anderson, 1938, Geol. Soc. America

Spec. Paper 16, p. 190, pi. 44, figs. 3, 4. 

Brewericeras JiuJenense (Anderson). Casey, 1954, Washington

Acad. Sci. Jour., v. 44, no. 4, p. 112.

Associated with B. Ireweri (Gabb) at Mesozoic locality 9492 are some ammonites that are possibly only 

a smooth variant of that species. They differ, however, by having a smaller umbilicus, slightly flatter 

flanks, and much weaker, finer ribbing that develops at 

a later growth stage. In addition the larger specimens 

have a slightly raised umbilical rim. These specimens 

have hitherto been assigned to "Ammonites" liaydenl 

Gabb (Martin, 1926, p. 346; Moffit 1938, table opposite 

p. 80; Imlay and Eeeside, 1954, p. 229), but their 

whorl sections compare in stoutness with those of B, 

hulenense (Anderson) (1938, pi. 44, fig. 4) rather than 

with those of B. liaydem (Gabb) (1864, p. 62, pi. 10, 

fig. 8a), which has similar weak ornamentation.

Figured specimens: USNM 130130, 130159. 

Localities: USGS Mes. loc. 9492, 14514.

Genus DESMOCERAS Zittel, 1884 

Desmoceras? sp. juv. 

Plate 17, figures 1-4

The species is represented by one internal mold. 

The specimen is small and has a subquadrate whorl 

section. At a diameter of 26 mm, its whorl height is 

13 mm, its whorl thickness is 14 mm and its umbilical 

width is 4 mm. The adoral part of the internal mold 

is marked by two conspicuous gently flexuous constrictions that arch forward slightly on the venter. Between the constrictions on the venter are faint riblets. 

The suture line is typical of Desmoceras.

This species differs from D. voyi Anderson (1938, 

p. 180, pi. 40, figs. 4-8) by having a subquadrate instead of an ovate whorl section. It is so much smaller 

than the figured specimens of D. merriami (Anderson) 

(1902, p. 103, pi. 6, figs. 135-138; 1938, p. 181, pi. 43, 

figs. 1, 2) that comparisons with that species would 

be meaningless.

Figured specimen: USNM 130135. 

Locality: USGS Mes. loc. 9492.

Genus PARASILESITES Imlay, 1959

The original description (Imlay, 1959, p. 184) is as 

follows:

This genus is characterized by its fairly evolute shell, wide, 

shallow umbilicus, strongly flexuous ribs and constrictions, 

presence of umbilical bullae, occasional rib furcation on the 

flanks, and by the auxiliaries of its suture line descending only 

slightly. It differs from the Barremian genus Silesites by the 

presence of umbilical bullae, by the furcation of some ribs low 

on the flanks, by the ribs being inclined forward strongly at 

the edge of the umbilicus, and perhaps by its auxiliaries not 

curving adorally. It differs from the upper Aptian-lower Albian 

genus NeosiJesites by the presence of umbilical bullae, by its 

ornamentation being much more sigmoidal, by its ribs branching much lower on the flanks, and by its primary ribs not 

splitting into many fine secondary ribs on the upper parts of 

the flanks. The suture line of Parasilesites is similar to that 

on small specimens of Silesites and NeosiJesites (Fallot 1920a, 

p. 54, 55; 1920b, p. 209-213). The tendency in the Silestidae 

(Wright, 1957, p. L372) for the auxiliaries to curve forward in 

advance of the first saddle, as illustrated by Uhlig (1883, 

pi. 18, figs. 11-14), does not bar Parasilesites from that 

family considering that the tendency, as discussed by Fallot 

(1920b, p. 209) is general only among adults. The type 

species of Parasilesites is Parasilesites ~bullatus Imlay, n. sp.

Parasilesites bullatus Imlay 

Plate 18, figure 1-8

Parasilesites bullatus Imlay, 1959, Jour. Paleontology, v. 33, 

no. 1, p. 184, pi. 29, figs. 1-8.

Only two specimens of this species are known. Whorls 

ovate in section, a little higher than wide, embracing about 

two-fifths. Flanks gently convex, rounding evenly into highly 

arched venter. Umbilicus fairly wide, shallow; umbilical wall 

low, steeply inclined, rounding evenly into flanks. Body 

chamber incomplete, represented by at least half a whorl.

The innermost whorls, exposed in the umbilicus of the type 

specimens, are marked by 7 or 8 deep, forwardly inclined constrictions and by faint forwardly inclined riblets. On the 

penultimate whorl the riblets are a little stronger and more 

flexuous, and number from 5 to 7 between successive constrictions. Those riblets adjoining constrictions are a little 

larger than the others and some of them bear weak bullae near 

the umbilical margin. On the body whorl both constrictions 

and ribs become stronger, many ribs are bullate, and some rib 

branching occurs at the bullae. On both the penultimate and 

body whorls the ribs and constrictions arch forward on the 

venter and most of the ribs are somewhat weakened on the 

venter. The venter of the internal mold at the beginning of the
CRETACEOUS AMMONITES FROM CHITINA VALLEY AND TALKEETNA MOUNTAINS 107

body chamber bears a distinct groove that has a length of only

8 mm. The ribs end abruptly at this groove and some terminate 

in swellings. The groove may represent a deformity and 

probably is not of specific importance.

The suture line is very simple. Its auxiliaries descend only 

slightly toward the umbilical seam. The ventral lobe is 

nearly as long as the first lateral lobe.

The holotype at a diameter of 27 mm has a whorl height of

9 mm, a whorl thickness of 8 mm, and an umbilical width of 

11.5 mm.

The species is characterized by developing distinct umbilical 

bullae, by having fairly regularly-spaced constrictions and 

ribs, and by some of the ribs bifurcating from the bullae. The 

small paratype resembles Silesites pusosiaformis Anderson 

(1938, p. 191, pi. 20, figs. 9, 10) from the early Albian of California, but is stouter, has coarser ribbing, more and deeper 

constrictions, and bears weak umbilical bullae.

Types: Holotype USNM 129872. Paratype USNM 129873. 

Occurrence: USGS Mes. loc. 9492.

Parasilesites irregularis Imlay, n. sp. 

Plate 18, figures 9-17

This species is represented by three specimens. Shell 

compressed, discoidal. Whorls subquadrate in section, 

higher than wide, embracing about one-third. Flanks 

flattened, rounding evenly into moderately arched 

venter. Umbilicus fairly wide, shallow; wall low, 

steeply inclined, rounding evenly into flanks. Body 

chamber represented by at least half a whorl. Aperture sinuous and has a pronounced ventral projection.

The ornamentation of the septate whorls, exposed 

in the umbilicus of the holotype, consists of 9 deep, 

flexuous constrictions between which lie from 2 to 5 

prominent, irregularly spaced, single flexuous ribs. 

The ribs adjoining the constrictions are somewhat 

stronger than the other ribs and many of them are 

swollen on the umbilical edge. Both constrictions and 

ribs weaken considerably on the venter and arch forward gently on the venter.

On the flanks of the body chamber the constrictions 

and ribs become more flexuous, stronger, and more irregularly spaced. Many of the ribs are- distinctly 

bullate at the umbilical edge. On the venter both constrictions and ribs arch forward strongly, the constrictions are narrow and deep, and the ribs are highly 

variable in strength. Most of the ribs bordering the 

constrictions on the venter are swollen. Between these 

ribs are bundles of riblets or striae that arise from the 

flank ribs on the margin of the venter and tend to fade 

out on the venter or to pass into swollen ribs.

The suture line is very simple, and its auxiliaries 

descend only slightly toward the umbilicus.

The holotype at an estimated diameter of 24 mm has 

a whorl height of 8 mm, a whorl thickness of 7 mm, 

and an umbilical width of 10 mm.

The presence of umbilical bullae readily distinguish 

this species from all species of Silesites, but its irregular ribbing bears some resemblance to that of S. vulpes 

(Coquand) as figured by Uhlig (1883, p. Ill, pi. 18, 

figs. 8, 9) from the Barremian of the Carpathian 

Mountains.

Types: Holotype USNM 130147. Para types USNM 130148. 

Locality: USGS Mes. loc. 9492.

Genus HULENITES Matsumoto, 1955

Hulenites cf. H. reesidei (Anderson)

Plate 18, figures 18-21

The genus Hulenites (Matsumoto, 1955, p. 122) is 

represented in the Chitina Valley by 4 specimens, of 

which 1 is much smaller than the other 3. Shell compressed, discoidal. Whorls ovate in section, higher 

than wide, becoming higher during growth, embracing 

about one-half preceding whorls. Flanks gently convex, becoming flatter during growth, rounding evenly 

into highly arched venter. Umbilicus moderately 

wide, shallow; umbilical wall low, vertical at base, 

rounding rather abruptly into flanks. Body chamber 

incomplete, represented by at least half a whorl.

The inner whorls, exposed in the umbilicus, bear 

many deep, forwardly inclined constrictions, but otherwise are smooth. The outer whorl of the smaller 

figured specimen has nine flexuous constrictions that 

arch forward strongly on the venter and become more 

deeply impressed during growth. Weak, forwardly 

inclined riblets are barely visible on the upper part 

of the flanks and on the venter. The outer whorl of 

the larger specimens bears constrictions that are deep 

near the umbilicus and shallow on the venter. Between 

successive constrictions are from 7 to 12 fine, forwardly 

inclined ribs that begin below the middle of the flanks, 

arch forward on the venter, and weaken along the midventral line. Some of the ribs bordering the constrictions are swollen.

The suture line cannot be traced accurately.

The larger specimen illustrated at a diameter of 33 

mm has a whorl height of 13.5 mm, a whorl thickness 

of 11 mm, and an umbilical width of 12 mm.

The largest specimens from the Chitina Valley are 

comparable in size with the small paratype of Hulenites 

reesidei (Anderson) (1938, p. 187, pi. 38, fig. 3) from 

California. They appear to have finer ribbing, a 

stouter whorl section, and a wider umbilicus. As these 

differences are all minor and as the range of variation 

in H. reesidei (Anderson) is unknown, the establishment of the Alaskan specimens of Hulenites as a distinct species does not seem justified at present.

Figured specimen: USNM 130134. 

Localities: USGS Mes. loc. 9480, 9492, 14466.

534624 O 60 4
108 SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY

Genus CLEONICERAS Parona and Bonarelli, 1896

Cleoniceras overbecki Imlay, n. sp.

Plate 19, figures 36-39

One small specimen of Cleoniceras lias been found in 

the Chitina Valley. Whorl compressed, much higher 

than wide, widest at umbilical edge, embracing about 

three-fourths of preceding whorls. Flanks flat, converging from umbilical edge to narrowly rounded 

venter. Umbilicus narrow; wall low, vertical at base, 

steeply inclined above, roimding abruptly into flanks. 

Body chamber unknowTn.

The umbilical edge bears 15 weak bullae that become 

weaker adorally. From these bullae pass weak, slightly 

flexuous ribs that incline forward on the flanks and 

arch forward on the venter. Some ribs remain single, 

but many bifurcate on the lower third of the flanks. 

Other ribs arise freely between the lower third and 

the middle of the flanks. All ribs become stronger 

ventrally, but are reduced somew^hat in strength along 

the midventral line. There are 42 ribs on the upper 

part of the flanks, or nearly 3 secondary ribs for each 

primary.

The suture line cannot be traced. The figured specimen at a diameter of 38 mm has a whorl height of 18 

mm, a whorl thickness of 10 mm, and an umbilical 

width of 7.5 mm.

The Alaskan species somewhat resembles the small 

specimen of Cleoniceras cleon (d'Orbigny) (1841, 

pi. 84, fig. 3) from France. That species, however, 

judging from a plaster replica of a typical specimen 

furnished by Eaymond Casey of the British Geological Survey, has more prominent bullae and much 

stronger, more flexuous ribs. C. Mcurvatoides (Sinzow) (1909, p. 29, pi. 2, figs. 7-18) from southern 

Russia has much more flexuous ribs and less prominent 

umbilical bullae. C. ~baylei (Jacob) at a comparable 

size, as figured by Spath (1925, p. 93; 1923, pi. 4, figs. 

6a, b), has a much stouter whorl section. C. leightonense Spath (1942, p. 701, 702, text fig. 247) is similar in shape and ornamentation, but is not strictly 

comparable because of the much greater size of the 

type. The adoral weakening of the ribs and bullae on 

the Alaskan species indicates that it loses its ornamentation at a much smaller size than does C. leightonense 

Spath.

The Alaskan specimen is the only one yet described 

from the Pacific coast of North America that fits the 

definition of Cleoniceras in all particulars. As its 

characteristics do not match those of the described 

species of Cleoniceras from Eurasia, it is deemed 

worthy of specific rank even though its adult characteristics are unknown.

This species is named in honor of R. M. Overbeck, 

who collected many of the ammonites from the Chitina 

Valley described herein.

Type: Holotype USNM 130141. 

Locality: USGS Mes. loc. 9492.

Genus PUZOSIGELLA Casey, 1954

Puzosigella cf. P. rogersi (Hall and Ambrose)

Plate 19, figures 33-35

Three specimens from the Chitina Valley probably 

belong to "Sonnratia" rogersi Hall and Ambrose (1916, 

p. 69) as interpreted by Anderson (1938, p. 197, pi. 20, 

figs. 6, 7). They are closely similar to the small plesiotype figured by Anderson 011 his plate 20, figure 6, but 

differ from the larger specimen figured by Anderson by 

losing their umbilical bullae at an earlier growth stage 

and by having finer, more closely spaced secondary 

ribs. Such differences appear to be normal for the 

species judging from the specimens in the Geological 

Survey collections from Oregon and California. As 

these collections show that the genus Puzosigella is 

characterized by considerable variability, the validity 

of the species discussed by Anderson should be established thoroughly before additional species are described. The Alaskan specimens may represent a distinct species from any described, but such cannot be 

proved now. The presence of the genus Puzosigella in 

Alaska is itself of stratigraphic importance as Puzosigella in California and Oregon is restricted to beds 

of early Albian age.

Figured specimen: USNM 130168. 

Locality: USGS Mes. loc. 8877.

Genus LECONTEITES Casey, 1954

This genus includes shells that are compressed and 

moderately involute and that develop a vertical umbilical wall. The shell is marked by flexuous ribs that are 

arched forward considerably on the venter and are 

reduced in strength along the midventral line. Bifurcation near the middle of the flanks is common. 

Weak flexuous constrictions that may be bordered by 

flared ribs on the venter are more evident on the internal mold than on the shell. The most finely ribbed 

species develop a sharp umbilical rim and weak umbilical bullae. The more coarsely ribbed species develop 

an abruptly rounded umbilical rim and more or less 

swollen primary ribs. The genus Puzosigella Casey 

(1954, p. 110) differs from Leconteites mainly by having more prominent umbilical bullae, by the flanks 

ribs originating in bundles at these bullae, and by possessing many, rather conspicuous, narrow constrictions 

on immature specimens.
CRETACEOUS AMMONITES FROM CHITINA VALLEY AND TALKEETNA MOUNTAINS 109

Leconteites modestus (Anderson) 

Plate 19, figures 4-6

Cleoniceras modestum Anderson, 1938, Geol. Soc. America Spec. 

Paper 16, p. 193, pi. 50, figs. 2-4.

This species is represented in the Chitina Valley by 

three specimens that compare closely in shape and ribbing with the paratypes from California figured by 

Anderson on his plate 50, figures 3 and 4. They all 

differ from the type specimens of L. lecontei (Anderson) (1938, p. 192, pi. 38, fig. 4, pi. 47, figs. 3-5) by 

having weaker less flexuous ribs and less conspicuous 

umbilical tubercles. However, collections on hand from 

California and Oregon suggest that L. modestus is 

merely a smooth variant of L. lecontei. This matter 

cannot be settled until larger collections are available. 

Illustrations of L. lecontei (Anderson) are shown on 

plate 19, figures 1-3, for comparison with the Alaskan 

specimens of L. modestus (Anderson) and L. deansi 

(Whiteaves) described herein.

Type: Plesiotypes USNM 130172, 130173. 

Localities: USGS Mes. loc. 9971, 11389.

Leconteites deansi (Whiteaves) 

Plate 19, figures 7-14

Olcostephanns (Astieria) deansi Whiteaves, 1893, Canadian 

Record Science p. 442-444, pi. 7, figs. 1, la.

The species is represented by 35 specimens. Shell 

small, discoidal, compressed. Whorls subovate, higher 

than wide, embracing about three-fifths. Flanks flattened below, converging slightly above to narrowly 

round venter. Umbilicus fairly narrow; wall low, 

vertical, rounding rather abruptly into flanks on inner 

whorls, but developing a rim on adult body chamber. 

The body chamber represents about three-fifths of a 

whorl.

The ribbing is fine and strongly flexuous. The primary ribs incline forward on the umbilical wall and 

on the lower third of the flanks where they recurve and 

then pass into pairs of slightly weaker secondary ribs 

that incline forward strongly on the venter. Bifurcation on the inner whorls occurs on the lower third of 

the flanks, but during growth the points of furcation 

rise to the middle of the flanks. In a few places furcation occurs at or near the umbilical edge. Many pairs 

of secondary ribs are separated by single ribs that arise 

above the middle of the flanks. All ribbing is much 

reduced in strength on the venter, even where shelly 

material is preserved. Tubercles are not present, although some of the primary ribs on the body whorl 

are faintly swollen at the umbilical edge. Each whorl 

is marked by five or six weak constrictions that are 

most evident on the venter.

The suture line is imperfectly preserved. It is characterized by the first lateral lobe being much longer 

than the ventral lobe. Its general plan is similar to 

that of L. lecontei (Anderson) (1938, p. 183, text fig. 3, 

no. 5, pi. 47, fig. 3), but its major lobes and saddles 

are more slender and less frilled, and its auxiliary 

lobes are much smaller.

The specimen shown on plate 19, figures 9-11, has 

been only slightly compressed. At a diameter of 40 

mm, its whorl height is 18.5 mm, its whorl thickness is 

13.5 mm, and its umbilical width is 10 mm. These dimensions are similar to those of the holotype.

L. deansi (Whiteaves) in general appearance is similar to Leconteites lecontei (Anderson) (see pi. 19, figs. 

1-3) from the early Albian of California and Oregon, 

but may be distinguished by having stronger primary 

ribs, by lacking tubercles, and by developing a sharp 

umbilical rim at a much later growth stage.

Type: Plesiotypes USNM 130164, 130170.

Localities: USGS Mes. Iocs. 2201, 8872, 9967a, 9072. Fragmentary specimens possibly belonging to L. deansi (Whiteaves) 

were found at Mes. Iocs. 8873, 8880, 9967, 9973, 14484.

Leconteites cf. L. deansi (Whiteaves) 

Plate 19, figures 15-27

From the same beds as specimens assigned to L. 

deansi (Whiteaves) and in part from the same localities (Mes. loc. 8872, 9972) have been obtained 25 specimens of Leco-nte'ttes that differ from L. deansi by having much stronger primary ribs, a slightly wider 

umbilicus, a stouter whorl section, and rounder flanks 

(pi. 19, figs. 19-27). These features would ordinarily 

be sufficient to justify assigning them to a distinct 

species. However, the presence at other localities (Mes. 

Iocs. 2201, 14484) of 4 specimens (pi. 19, figs. 16-18) 

that are intermediate in appearance suggest that the 

25 stout, coarsely ribbed specimens are merely an extreme variana of L. deans/ (Whiteaves). Their status 

cannot be settled definitely by the specimens on hand.

Figured specimens: USNM 130158, 130162, 130169, 130174. 

Localities: USGS Mes. loc. 2201, 8872, 8873, 8878, 9972, 14484.

Genus LEMUROCERAS Spath, 1942 

Lemuroceras talkeetnanum Imlay, n. sp.

Plate 18, figures 34-41

"iLemuroccras cf. L. indietim Spath. McLearn, 1945, Geol. Survey Canada Paper 44-17 (2d ed.), pi. 5, fig. 4.

This species is represented by two specimens that 

retain some of the inner shelly layer. On this layer 

feather structures is well shown at one place (Arkell, 

in Arkell, Kummel and Wright, 1957, p. L92). The 

whorls are subquadrate in section and higher than wide
110 SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY

and embrace about three-fifths of preceding whorl. 

The flanks are flattened, but become gently convex on 

the body chamber. The venter is nearly flat on the 

sutured part of the shell and gently rounded on the 

body chamber. The umbilicus is moderately narrow; 

the umbilical wall is low and steeply inclined and 

rounds evenly into the venter. The body chamber is 

represented by half a whorl and appears to be complete.

The ribbing on the septate part of the body whorl 

is prominent, widely spaced, and strongly flexuous. 

About half of the ribs arise on the umbilical wall, are 

most prominent at the umbilical edge, incline forward 

strongly low on the flanks, recurve near the middle of 

the flanks, and arch forward strongly on the upper 

part of the flanks and on the venter. The remaining 

ribs either arise freely near, or below, the middle of 

the flanks, or are indistinctly connected with the longer 

ribs at about the top of the lower third of the flanks. 

All ribs are equally strong on the venter, and all are 

slightly reduced in strength along the midventral line.

The ribbing on the body chamber fades out rapidly 

toward the aperture and becomes less strongly arched 

on the venter. Near the aperture only weak lines of 

growth are visible where the shell is preserved and the 

internal mold is quite smooth.

The body chamber has been crushed laterally and 

cannot be measured. At the beginning of the body 

chamber, the whorl height is 17 mm, and the whorl 

thickness is 13 mm.

The suture line is quite similar to that of L. aburense 

(Spath) (1933, p. 801, pi. 129, fig. 5) from India. The 

first lateral lobe is a little longer than the ventral lobe. 

The first lateral saddle is very wide. The other lobes 

and saddles are relatively much smaller. The auxiliaries descend slightly toward the umbilicus.

This species is remarkably similar to Z. indicum 

(Spath) (1933, p. 801, pi. 128, figs. 4a, b, '5a, b) from 

India and Madagascar (Collignon, 1949, p. 68, 69, pi. 

12, figs. 2, 2a, b, pi. 14, fig. 2). It is distinguished from 

that species mainly by being more involute and by its 

ribs arching forward more strongly on the venter. It 

appears, also, to have flatter flanks, but that may be a 

result of compression. The primary ribs are not nearly 

so prominent at the umbilical edge as in the holotype 

of Z. indicum (Spath), or in the ammonite fragment 

figured by McLearn (1945, pi. 5, fig. 4), from the western interior of Canada, but the ribs are of nearly the 

same strength as on the paratype of Z. indicum 

(Spath) (1933, pi. 128, fig. 5a).

Types: Holotype USNM 13015. Paratype USNM 130150. 

Locality: USGS Mes. loc. 24877.

Lemuroceras? sp. juv. cf. L. dubium Collignon 

Plate 18, figs. 26-29

One small specimen has a subquadrate whorl section, 

flattened flanks and venter, a moderately wide umbilicus, and a low vertical umbilical wall that rounds 

evenly into the flanks.

The ribs are strongly flexuous on the flanks and arch 

forward moderately on the venter. Most ribs begin 

on the umbilical wall and remain single on the flanks. 

About one-third of the ribs bifurcate at, or below, the 

middle of the flanks, or are indistinctly connected with 

secondary ribs. A few secondary ribs arise freely on 

the flanks. The secondary ribs are as strong, or nearly 

as strong, as the primary ribs. All ribs are slightly reduced in strength along the midventral line. Six weak 

constrictions are present, but are conspicuous only on 

the venter.

At a diameter of 25 mm, the whorl height is 10 mm, 

the whorl thickness is 8 mm, and the umbilical width 

is 7.5 mm.

The suture line is not preserved.

This specimen is assigned to Lemuroceras rather 

than to Leconteites because of the characteristics of its 

ribbing, but it does have a vertical wall, a feature 

which is characteristic of Leconteites. Its appearance 

in lateral view is similar to that of Z. dubium Collignon from Madagascar (1949, p. 74, pi. 15, figs. 2, 2a, 

b), but it has fewer secondary ribs and more primary 

ribs per whorl, is more compressed, and has a vertical 

umbilical wall.

Figured specimen: USNM 130157. 

Locality: USGS Mes. loc. 14484.

Subgenus SUBAHCTHOPLITES Casey, 1954, revised Imlay

Subarcthoplites Casey (1954, p. Ill) based on Lemuroceras belli McLearn (1945, pi. 3, figs. 17,18) from 

the western interior of Canada was considered by its 

author to be more similar to the boreal genus Arcthoplites than to Lemuroceras from India and Madagascar. The discovery of adult specimens of Lemuroceras belli McLearn in northern Alaska shows, however, that it differs from Arcthoplites by lower points 

of rib branching, by the presence of constrictions, and 

by its ribs fading on the body chamber instead of becoming coarser. In these respects it is identical with 

typical species of Lemuroceras from India and Madagascar. Lemuroceras belli McLearn differs from the 

typical species only by having rounder flanks, less 

flexuous ribbing, and a less abrupt change in the direction of ribbing on the lower part of the flanks. These 

differences are slight and are not considered worthy of 

more than subgeneric rank.
CRETACEOUS AMMONITES FROM CHITINA VALLEY AND TALKEETNA MOUNTAINS 111

lemuroceras (Subarcthoplites) aff. L. belli McLearn 

Plate 18, figures 23, 30-33

Two immature specimens of Lemuroceras from the 

Chitina Valley differ from L. 'belli McLearn (1945, pi. 

3, figs. 17, 18; 1948) by being more compressed and by 

having weaker ribs that bifurcate less commonly and 

are more widely spaced on the venter.

The small specimens from the Chitina Valley each 

have about one-third of a whorl of body chamber. On 

the septate part of the shell the primary ribs incline 

forward strongly on the umbilical wall and on the 

lower third of the flank where most of them either 

bifurcate or are indistinctly connected with a secondary 

rib. All ribs curve backward near the middle of the 

flanks and then arch forward gently on the venter. 

On the body chamber, furcation becomes less common 

and secondary ribs become fewer. All ribs continue 

across the venter with only slight reduction in strength 

as compared with the ribs on the flanks.

The suture line has a very wide first lateral saddle 

and a wide trifid first lateral lobe that is only slightly 

longer than the ventral lobe. The auxiliaries are 

curved slightly adorally. The pattern of the suture 

is similar to that of L. aburense (Spath) (1933, pi. 

129, fig. 5) from India.

Figured specimen: USNM 130136. 

Locality: USGS Mes. loc. 9492.

Arcthoplites? sp. 

Plate 18, figures 22, 24, 25

Two fragments bear high, thin, widely spaced ribs 

similar to those on the outer whorl of Arcthoplites 

jachromensis (Nikitin) (1888, p. 57, pi. 4, fig. 1) from 

the lower or middle Albian of Kussia. On the venter of 

the internal mold the ribs arch forward and become a 

little broader and lower. In places where the shell is 

preserved the ribs are much thicker than on the internal mold. As the lower parts of the flanks are not 

preserved, the fragments could be assigned as readily 

to Tetrahoplites or Pseudosonneratia as to Arcthoplites.

Figured specimen: USNM 130137. 

Locality: USGS Mes. loc. 9492.

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INDEX

[Italic numbers indicate descriptions]

A Page 

aburense, Lemuroceras _______________________ 110,111

affine, -BeM<_awi.ceras______-_____________________ 105

glabrum, Desmoceras.--- ______ ____________ 105

agassizianum, jfifossma?eZ_a-__-_-----____________ 99

akuschaensis, I'aldedorseUa---..----------------- 100

alaskana, P«zos.a____________________ 91,98,704, pi. 16

alaskanum, Callizoniceras----------------------- 101

Callizoniceras (Wollemanniceras)----_._ 91,98,707,

pi. 12

Albian ammonites, geographic distribution ___ 98 

Albian faunules _________ _______________________ 93

aldersoni, Calliphylloceras------------- 91,98,59, pi. 11

Ammonite faunules and correlations-.._________ 89-93

Ammonites.----------------.---------.--------- 100

breweri __________________________________ 105

haydeni______--______---_--____________ 106

.. 1 nagaudryceras.--- __________________________ 88, 89, 99

oMroriwrn----.-------------- 89,91,98,99, pi. 11

sp. indet___________________________________ 91,98

anglicus, Inoceramus---- _--____--_-____________ 91

,lrctf-o;....es ----_-_---___--- 88,110,111

jachromensis-_--- _________________________ 111

sp_____________._______________ 91,98,777, pi. 18

(.ls..ero) deansi, Olcostephanus----------- _______ 109

Astieridiscus-. _________________________________ 102

AucelJa ..._____________________________________ 89

crassicollis- ________________________________ 89

pottos.. - --._ - _ __ __ 89

^iMCf/Hwa.-..--- _. _ _ 89,91,94

AuceUina sp____________________________________ pi. 19

aurarium, Anagaudryceras..- ______ 89,91,98,99, pi. 11

Lytoceras (Kossmatetta)---- _________________ 99

B 

baylei, Cleoniceras- ___________________________ 108

Bear Creek_______________________________ 88,89,91,96

belli, Lemuroceras---------------- 92, 97,110, 777, pi. 18

Lemuroceras (Subarcthoplites)- 91, 92,98, 111, pi. 18 

Beaudanticeras_.__--_.__-___- ____ 88, 93, 94,105, 106

affine.-- ___________________________________ 105

breweri- ___________________________________ 105

glabrum. _____________________ 92, 93, 98, 705, pi. 16

huhne use ________________________________ 106

laemgatum- ------_-__----_________________ 105

Sutherland!-- ________________________________ 105

( Grantziceras) _____.______________________ 88

multiconstricfum-- ____________ 92,98, 705, pi. 14

Beudant iceratinae._--.__-__--____-_____________ 88

bicurvatoides, C.eo?»'efros__-----_________________ 108

bifurcata, Kennicoftid-. _________________________ 91

Billy Creek . . .__._____________________ 88,9ti

Biologic analysis.....___________________________ 87-88

breweri, Ammonites.-^- ________________________ 105

Beudanticeras-- _____________________________ 105

Brewericeras^------^,--- 91, 92, 94, 98, 705, pi. 17

Brewericeras- _________________________ 88, 93, 94, 97,105

breioeri.---------- _________ 91, 92, 94, 98, 705, pi. 17

faunule..___-__-, -__-______- 91,92,97

haydeni.-----------_-..- ___________________ 91,106

Iwlenense------.--------- 89, 91, 94, 98, 706, pi. 17

zone-.. _ ___ 91,92,94,98

bullatus, Parasilesites-------------- 91, 98, 706, pi. 18

C Page 

calif or nicum, Hypophylloceras-- ______ 91, 9S, pi. 11

Calliph yttoceras. ________________________________ 88.99

o.derso?!L_-----_-__-___________. 91, 98, 99, pi. 11

n.z.na..Mm__ _______________ 91, 98, .99, pi. 11

Calliphylloceratinae__ _________________________ 88

Ca?..zon.«ros__---____ ________ 88,93, 94, 97,101,102,103

a7asta7ni7n_-____--__________________________ lot

AOJ/.T. - _ _____-_ __-_-_____-- 101

( Wollema nnicerast) __________________________ 91

a?as/.att«.7.__________________ 91, 98, 707, pi. 12

/o/i7.nense---_____---_- 91, 98. 707, pi. 12

fcf!7AaeA-.----------_-_____--_- ------ 101

Canyon Creek____________________________ 88,89,91,97

cappsi, Kossmatella_____-_-_-_________- 91,98.99, pi. 12

Cephalopoda _________________________________ 97

chirichensis, Puzosio- ____________________________ 100

Chitina River__-_----_-________________________ 96

Chitina Valley_---------_--_-_-__--___------___ 88-89

chitinanum, Phyllopachyceras-,- _______ 91,97, 98, pi. 11

Chokosna River________________________________ 96

Clansayes beds. ---------- -- ---------------_ 100

Clearwater formation__.________________________ 92

deon, Cleanic'eras- ______________________________ 108

C7«on.ceros_____-_-____________ _________ 88,92,94,108

baylei ________________________________________ 108

bicurvatoides- _______________________________ 108

c7eon-__.-------- ___________________________ 108

leightonense. ________________________________ 108

modestMTO___---__-___-______________________ 109

overbecki_ _________________________ 91,98.70S, pi.19

Cleoniceratinae-____________________________ ___ 88

comancheanus, /»ocfram»s______________________ 91

Copper River basin ____________________________ 88

Correlations and ammonite faunules_______---__ 89-93

crassicolHs, Aucella _____________________________ 89

crassicostatus, iffon.f/_es________________________ 91

crassus, Moffitites.----------- _________ 89, 98,70*, pi. 14

D 

deansi, £mwte'/«!____________ 91, 94, 98, 709, pi. 19

Olcostephanus (.4s?.fra)_____________________ 109

Z>fswofcro.s_________________________ 88,94,100.102,106

o/?/«e glabrum^---. __________________________ 105

merria m. ____________________________________ 106

coy. _ _ _______________________________________ 106

sp. juv--_------_-----____- 91, 98, 706, pi. 17

Desmoceratidae ________________________________ 88, 93

Desmoceratinae ________________________________ 88

DouvilMceras.------.---------------------- 88,89,92

mammillatum zone__________________________ 92

dubium, Lem!/rocfras_-_________________ 98, 770, pi. is

F 

Flume Creek___________________________________ 88,96

Fohlin Creek______________________________ 88,89,91,96

fohlinense, Callizoniceras (WoUemanniceras)- 91.

98, 101, pi. 12 

Fourth of July Creek________________________ 89,91,96

JV_oW.fm,s___ _____________________________ 88,93,70..

singutare.- --------- 92, 93, 94, 97, 98, 70;., pi. 14

faunule.________________________________ 92-93

G Page 

._-__-__---_---------__- 88

sp--------------------------------------- 98

Gastroplites--- 92

kingi. ------------------------------------- 97

Gastroplitinae - ----- - --. ----- 88

Gates formation___________._____-_-- _ 92

Geographic distribution, Albian ammonites-___ 98

getulina, Valdedorsella---.. ------------------- 100

Gibraltar Hill_________._________-_-__ -... 93

glabnnn, Beudanticeras-- ________ 92,93,98, 705, pi. 16

Desmoceras affine--------------------------- 105

Placenticeras-------------------------------- 105

Grantziceras------------------------------------ 105

(Grantziceras), Beudanticeras ------------------ 88

multicnnstrictum, Beudanticeras-- 92, 98, 705, pi. 14

Guadrycerat inae -_-_ - 88

H

Harmon shale member, Peace River formation.- 92 

haydeni, Ammonites-------------------------..- 106

Brewericeras------------------------------ 91,106

Hoplites dentatus zone---_-----__--------------- 89

Hoplitidae- ------ ----_-----_--- -- 88,94

hourcqi, Valdedorsella--------------------------- 100

hoyeri, Callizoniceras---------------------------- 101

hulenense, Beudanticeras----------------.------- 106

Brewericeras-- ------- 89, 91, 94, 98, 106, pi. 17

Hulenites -- ----- .-- 88,92,93,97, 104, 107

reesidei----------------.------ 91, 98,104, 707, pi. 18

Ilypophylloceras _________________________________ 88, 98

ca///brn.CM.n____ ------------------- 91,98, pi. 11

I 

indicum, Lemuroceras----------------------- 92,93,109

indigenes, Afelchiorites ----------------- -____ 104

In ocera mus------------------------------ 88, 91

anglicus------------------------------------ 91

comancheanus-------- _______________________ 91

irenense, Lemuroceras-------,--------------- 92,93,103

irregularis, Parasilesifes-.. ____________ 91, 98, 707, pi. 18

J 

jachromensis, Arcthoplites. ______________________ Ill

keilfyacki, Callizoniceras (Wollemanniceras)------ 101

Kennicott formation____________________-_______ 98

Kennicott Glacier--------------- 88,89,96

Kennicott River___,____________________________ 96

Kennicottia-----------------.-------- 88,93,94,102,103

bifurcata. ----------------- 91, 98, 705,104, pi. 15

rugosa-------------------------- 91, 98, 70?, pi. 15

kingi, Gastroplites------------------------------- 97

Kossmatella ________________________________ 88,99

agassi:ianum------------------------------- 99

cappsi---------------------- 91, 98,99, pi. 12

gainesi- __________.._____-----------_----_-- 99

(Kossmatella) aurarium, Lytoceras.. ...... __. 99

Kossmatellinae__........ T .._---._--.-.----.---- 88

Kossmaticeratidae_. _ ..-_- -_.-----...--- 88,94

113
114 INDEX

Page

Kuskulana Pass.. 

Kuskulana Eiver_

laeve, Ptychoceras_______.________ 91, 98, 100, pi. 12

laevigatum, -Be«<-<.w?.ceras__-____________________ 105

Lakina Elver. --- - -______._____________.___ 96

lecontei, Leconteites-------________. ______________ 109

Leconteites _-.-_- ............ 88, 89, 91, 93, 94, 97, MS, 110

crassicostatus______ _____________......... 91

deansi....... ..__________ 91, 94, 98, 109, pi. 19

faunule__.____________________________ 91-92

..con.eL____________________________________ 109

zone__._____-__-.._______._._- 89,91,92,94

modestus.... _______ 89, 91, 94, 98, 109, pi. 19

faunule_________________________________ 89,91

sp.

leightonense, Cleoniceras. - ___________________ 108

Lemuroceras... ________________ 88,93,94,97,109,110

aburense........................... ___._ 110, 111

6e..» ....................... 92, 97, 110, 111, pi. 18

zone..__________________________________ 92

dtt&.MTO_____________________________ 98, 110, pi. 18

indicum................................ 92, 93, 109

irenense _______________________________ 92, 93, 103

talkeetnanum, ---- ______..... 92, 98, J09, pi. 18

(Subarcthoplites) - - -. - 88, 92, 93, 94, 97 

belli-. ___________________ 91, 92, 98, ///, pi. 18

LeymerieUa tardefurcata zone___.___-____________ 89, 92

Loon Elver formation__________________________ 92

Lunatodorsella __________________________________ 100

Lytoceras (Kossmatella) aurarium- ______________ 99

M 

McCarthy Creek_________.______________ 88, 89, 91, 96

Matanuska formation__________________._______ 96, 98

Melchiorit.es---------- __________________________ 104

indigenes.-... _______________________________ 104

merriami, Desmoceras..- ________________________ 106

modestum, Cleoniceraa..-....................... 109

modestus, Leconteites- ________ 89, 91, 94, 98, /09, pi. 19,

Afoj?..i.es--- _ -- - 88, 91, 93, 101

crassus-------------. ____________ 89, 98, ..02, pi. 14

ro6(.*«Ms___.__________________ 91, 94, 98, 102, pi. 13

faunule.________________________________ 91-92

Moosebar formation..._________________________ 92

multiconstrictum, Beudanticeras (Grant z.ceras)___ 92,

98, 106, pi. 14 

N 

Nelchima limestone____-______-__----_....... 88, 96

Neosilesites-- _....___________________ 106

Nizina Qlacier_____._______________.... 88, 91, 93, 96, 97

Page

nizinanum, Calliphylloceras.... __-.___ 91, 98, 99, pi. 11 

Notikewin member, Peace Elver formation.__ 92

O

pallasi, Aucella..... ______.__.___----______----_ 89

Parasilesites----- - -------.......... 88, 92, 94, 106

bullatus--- ------------ 91, 98, 106, pi. 18

irreffw.ans..---------------------- 91, 98, 107, pi. 18

Peace Elver formation, Harmon shale member _ _ 92 

Notikewin member_-___--_--___-_-__------- 92

perrinsmithi, Puizosigella..----------------- __ 89,98

Phylloceratidae. _..___._-_____--.-.____-----._. 88,94

Phylloceratinae. .--.---.---.. --------- 88

Phyllopachyceras --------.________----___-_-_. 88,97

chitinanum---..----- --------- 91,97,98, pi. 11

shastalense..---------- ______-______----_-___ 91,98

theresae...---------------------------------- 98

Placenticeras glabrum,--......................... 105

Pseudohaploceras.- ...___.____________.______- 102,103

Pseudoleymeriella. ______________ ____--._- 88

Pseudosonneratia------------------------------ 111

Ptychoceras--.................................. 88,100

laeve----- - - 91, 98, 100, pi. 12

Ptychoceratidae--____-_--_-____-__-_.--------__ 88,94

Pu:oaia 88, 94,103,104

alaskana 91, 98, 104, pi. 16

chirichensis--------------------------------- 100

qiLensledti----------------------------------- 104

subquadrata- ------------------------------ 103

sp..............- .. . 91

sp in-let.-----.------------------------- 98

puzosiaformis, S..e«-es________________-___-_--__ 107

PitzosiffeHo-... 88, 89, 91, 93, 94, 97,108

faunule.- - -- - ----- 89,91

perrinsmithi.--------------------------- 89,98

rogersi ------------------------- 89, 98, 108, pi. 19

.op 89,98

spp... .. .. . 89,94

____-_.____-_____ -------------- 88

Queen Charlotte Islands...______________ 88,91,93,100

quenstedti, Pw20*.O-------_-__-----------------_- 104

reesidei, Hulenites---------------- 91, 98,104, 107, pi. 18

robustus, Moffitites- ---------- 91, 94, 98,102, pi. 13

rogersi, Puzosigella.--. _________ 89, 98JOS, pi. 19 

Sonnratia.---------------------------------- 108

rugosa, Kennicottia------------------- 91, 98,103, pi. 15

S Page 

shastalense, Phyllopachyceras- .... _._._-.-_-_. 91, 98

Silesites -- --- 89,106,107

puzosiaformis------------------------------- 107

vulpes....-.-------------------------------- 107

Silesitldae....- - -------- -- --. 88,94

singulare, Freboldiceras...... 92,93, 94, 97, 98, 102, pi. 14

Slatka Creek.- . ..-- -. 88 

Sonnratia rogersi-.------------------------------ 108

Stratigraphic summary_____ ____ ____ 88-89

Subarcthoplites . ...... 92, 110

(Subarcthoplites) belli, Lemuroceras......-..-. 91,92,98

Lemuroceras__.____________ 88,92,93,94,97

subquadrata, Puzosia, -------------------------- 103

Summary of results_._-_______..--___.-_-_-- 93-97

Sutherland!, Beudanticeras----------------------- 105

Systematic descriptions......____________._ 97-111

taffi, Puzosigella-------------------------------- 89, 98

Talkeetna Mountains.._-_______-----____--._ 88

talkeetnanum, LemuToceras.-.--- _-- 92, 98, 109, pi. 18 

Tetragonites- -------------------------- 88,89,100

timotheanus.----------------- 91,98, 100, pi. 12

sp..___-_--_----.---__ ____. --- _- 92

sp. indet____- -_ - -- -- 98

Tetragonitidae._________-----_______ 88,94

Tetragonitinae.--------.--_--_-------- - 88

Tetrahoplites. ____________.-_-______----_ 111

theresae, Phyllopachyceras--------------------- _ 98

timotheanus, Tetragonites.-- __---.__- 91,98, 100, pi. 12 

Trail Creek. 91,96

V

Valdedorsella _.. 88, 92,94,100,102,103 

akuschaensis---------------- _. _. _ _.. 100

getulina ------------------_.____... 100

hourcqi--------------------- .... _._ 100

whiteavesi. - 91,98,100, pi. 11

voyi, Desmoceras-------------------------------- 106

vulpes, Silesites--.------------------------------ 107

W

whiteavesi, Valdetiorsella- _____.... 91, 98, 100, pi. 11

Wollemanniceras-------------------------------- 101

(Wollemanniceras) alaskanum, Callizonkeras _._ 91,

98.WJ.pl. 12 

Callizoniceras------------------------------- 91

fohlinense, Callizoniceras.-------- 91,98, 101, pi. 12

keilhacki, Callizoniceras--- ____-_____---___ 101

Young Creek.... 88,89,91,96

O
PLATES 11-19
PLATE 11

[Figures natural size unless otherwise indicated]

FIGURES 1-5. Phyllopachyceras chitinanum Imlay, n. sp. (p. 97).

Holotype USNM 130142, from USGS Mes. loc. 9492. Suture line drawn from adapical end of body chamber. 

6-12. Calliphylloceras nizinanum Imlay, n. sp. (p. 99).

All specimens from USGS Mes. loc. 9492.

6. 10, 11. Paratype USNM 130139a.

7. 8. Holotype USNM 130138. 

9. Paratype USNM 130139b.

12. Paratype USNM 130139c.

13-17. Calliphylloceras cf. C. aldersoni (Anderson) (p. 99). 

All specimens from USGS Mes. loc. 9972.

13. Specimen USNM 130161a showing traces of finely ribbed shell.

14. Specimen USNM 130161b.

15-17. Ventral, cross section, and lateral views of specimen USNM 130161c. 

18, 19, 24. Anaqaudryceras aurarium (Anderson) (p. 99).

Both specimens from USGS Mes. loc. 14485. 

18, 19. Immature septate specimen, USNM 130154a. 

24. Adult specimen USNM 130154b showing fine striations on the shell and deep constrictions on the mold. Body

chamber represented by three-fifths of a whorl. 

20-23, 25-28. Valdedorsellal whiteavesi Imlay, n. sp. (p. 100).

Both specimens from USGS Mes. loc. 9492. 

20-23, 25. Holotype, USNM 130145. Suture line drawn at diameter of 11.5 mm. Note figures 21 and 22 are

identical views at different magnifications. 

26-28. Paratype USNM 130146.

29. Hypophylloceras cf. H. californicum (Anderson) (p. 98) 

Specimen USNM 130132, from USGS Mes. loc. 9492.
GEOLOGICAL SURVEY PROFESSIONAL PAPER 354 PLATE 11

-^ *-' '

24

PHYLLOPACHYCERAS, CALLIPHYLLOCERAS, ANAGAUDRYCERAS, 

VALDEDORSELLA1, AND HYPOFHYLLOCERAS
GEOLOGICAL SURVEY PROFESSIONAL PAPER 354 PLATE 12

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CALLIZONICERAS, KOSSMATELLA, PTYCHOCEKAS, AND TETRAGONITES
PLATE 12

[Figures natural size unless otherwise indicated]

FIGURES 1-10. Callizoniceras (Wollemanniceras) fohlinense Imlay, 11. sp. (p. 101). 

All specimens fronvUSGS Mes. loc. 14484.

I, 2, 10. Holotype USNM 130155.

3. Paratype USNM 130156a.

4. 5. Paratype USNM 130156b.

6. Paratype USNM 130156c. Weaker ribbed than the holotype. 

7-9. Paratype USNM 130156d. Stronger ribbed than the holotype. 

11-16. Callizoniceras (Wollemanniceras) alaskanum Imlay, n. sp. (p. 101). 

Both paratypes from USGS Mes. loc. 8873.

II, 12. Holotype USNM 130165, from USGS Mes. loc. 9976. 

13, 14. Paratype USNM 130166a. 

15, 16. Paratype USNM 130166b. 

17-22. Kossmatella cappsi Imlay, n. sp. (p. 99).

Both paratypes from USGS Mes. loc. 9492. 

17, 19. Paratype USNM 130140a. 

21, 22. Paratype USNM 130140b.

18, 20. Holotype USNM 130160, from USGS Mes. loc. 14514. 

23. Ptychoceras cf. P. laeve (Gabb) (p. 100).

Specimen USNM 130163, from USGS Mes. loc. 9972. 

24-28. Tetragonites aff. T. timotheanus (Pictet) (p. 100).

Both specimens from USGS Mes. loc. 9492.

24, 28. Adult showing three-fifths of a whorl of body chamber, USNM 130131a. 

25-27. Immature specimen USNM 130131b.
PLATE 13

[Figures natural size unless otherwise indicated]

FIGURES 1-13. Moffitites robustus Imlay. (p. 102).

1-3, 5. Septate paratype USNM 129875a, from USGS Mes. loc. 9972, is slenderer than most specimens of the

species.

4, 9. Small septate paratype USNM 129876a, from USGS Mes. loc. 14485. 

6-8. Normally stout septate paratype USNM 129875b, from USGS Mes. loc. 9972. Note tendency of ribs to li

become threadlike on the venter. '

10. 13. Holotype USNM 129874, from USGS Mes, loc. 2191. About three-fifths of a whorl belongs to the body 

chamber.

11. 12. Lateral views of paratype USNM 129876b, from USGS Mes. loc. 14485. Shows characteristic ribbing |l 

on inner whorls.
GEOLOGICAL SURVEY PROFESSIONAL PAPER 354 PLATE 13

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MOFFITITES ROBUSTUS
GEOLOGICAL SURVEY PROFESSIONAL PAPER 354 PLATE 14

BEUDANTICERAS, MOFFITITES, AND FREBOLDICERAS
PLATE 14

[Figures natural size unless otherwise indicated]

FIGURES 1, 2. Beudanticeras (Grantziceras) multiconstrictum Imlay (p. 105).

Holotype USNM 128721, from USGS Mes. loc. 24877. 

3-7. Moffitites, crassus Imlay, n. sp. (p. 102).

3, 4. Paratype USNM 130176, from USGS Mes. loc. 14487. 

5-7. Holotype USNM 130175, from USGS Mes. loc. 8878. 

8-17. Freboldiceras singulare Imlay (p. 102).

All specimens from USGS Mes. loc., 24877.

8-10. Lateral views and suture line of paratype USNM 129869a.

11, 12, 15-17. Holotype USNM 129868. Note fine striations on shell. Suture line drawn at whorl height of 15 

mm.

13. Paratype USNM 129869b.

14. Paratype USNM 129869c. The smooth body chamber occupies about three-fifths of a whorl.
PLATE 15

[Figures natural size unless otherwise indicated]

FIGURES 1 6. Kennicottia bifurcata Imlay (p. 103).

1-5. Holotype USNM 129870, from USGS Mes. loc. 9972. Suture line drawn at diameter of 63 mm.

6. Paratype USNM 129871, from USGS Mes. loc. 8873. Shows furcation of ribs on inner whorls. 

7-13. Kennicottia rugosa Imlay, n. sp. (p. 103).

7. 8, 11. Paratype USNM 130153a, from USGS Mes. loc. 14485.

9, 10. Paratype USNM 130153b, from USGS Mes. loc. 14485.

12, 13. Holotype USNM 130152, from USGS Mes. loc. 9489. I

I I
GEOLOGICAL SURVEY PROFESSIONAL PAPER 354 PLATE 15

y-, ^k-«!>^V'-fc^T-, *^£ id£- -^l^f ^. ">s^^j:,= $m

12

KENNICOTTIA B1FURCATA AND K. RUGOSA
GEOLOGICAL SURVEY PROFESSIONAL PAPER 354 PLATE 16

19

PUZOSIA ALASKANA AND BEUDANTICERAS GLABRUM
PLATE 16

[Figures natural size unless otherwise indicated]

FIGURES 1-13. Puzosia alaskana Imlay, n. sp. (p. 104).

1-4. Holotype USNM 130143, from USGS Mes. loc. 9492.

5-13. Paratypes USNM 130144, from USGS Mes. loc. 9492. Lateral views 8 to 13 shows differences in strength

of ribbing and in constrictions. The suture lines were drawn from the specimen shown in figure 5. 

14-21. Beudanticeras glabrum (Whiteaves) (p. 105).

Plesiotypes USNM 130149, from USGS Mes. loc. 24877. Figures 14 and 19 represent fairly smooth specimens. 

Figure 15 represents a specimen with large bulges or ribs. Figures 16 to 18 show prominent constrictions. 

Figures 20 and 21 represent a specimen that develops weak lateral bulges. All these specimens are septate.
PLATE 17

[Figures natural size unless otherwise indicated]

FIGURES 1-4. Desmoceras? sp. juv. (p. 106).

Specimen USNM 130135, from USGS Mes. loc. 9492. Suture drawn at whorl height of 10 mm. 

5-10, 12, 13. Brewericeras breweri (Gabb) (p. 105).

Plesiotypes USNM 130133, from USGS Mes. loc. 9492. Figures 5-7 represent a typical specimen. Figure 8 

illustrates feather structure on the septate part of the shell and likewise bears ribbing typical of the species. 

Figures 9 and 10 and figure 13 represent two specimens in which coarse ribbing appears at an earlier growth 

stage than is typical in the species. The suture line was drawn at the adapical end of the body chamber from 

the specimen shown on figures 5-7. 

11, 14-16. Brewericeras cf. B. hulenense (Anderson) (p. 106).

11. Specimen USNM 130159, from USGS Mes. loc. 14514. 

14-16. Specimens USNM 130130, from USGS Mes. loc. 9492.
PROFESSIONAL PAPER 354 PLATE 17

DESMOCERASt SP., BREWERICERAS BREWERI, AND £. HULENSE
GEOLOGICAL SURVEY 

f

PROFESSIONAL PAPER 354 PLATE 18

37

PARASILESITES, HULENITES, ARCTHOPLITES1, AND LEMUROCERAS
PLATE 18

[Figures natural size unless otherwise indicated]

FIGURES 1-8. Parasilesiles bullalus Imlay (p. 106).

1-4, 8. Holotype USNM 129872, from USGS Mes. loc. 9492. 

5-7. Paratype USNM 129873, from URGS Mes. loc. 9492. 

9-17. Parasilesiles irregularis Imlay, n. sp. (p. 107).

All types are from USGS Mes. loc. 9492. 

9-11, 16, 17. Lateral, ventral, and apertural views and suture line of holotype USNM 130147. Suture line drawn

at diameter of 13 mm. Note that figure 16 is an enlargement of figure 9. 

12, 13. Paratype USNM 130148a. 

14, 15. Paratype USNM 130148b. 

18-21. Hulenites cf. H. reesidei (Anderson) (p. 107).

Specimens USNM 130134, from USGS Mes. loc. 9492.

22. 24, 25. Arcthoplites? sp. (p. 111).

Specimen USNM 130137, from USGS Mes. loc. 9492. Figures 24 and 25 represent ventral and lateral views of 

one specimen.

23. 30-33. Lemuroceras (Subarcthoplites) aff. L. belli McLearn (p. 111).

Both specimens from USGS Mes. loc. 14484. 

23, 30-32. Specimen USNM 130l36a. Suture line drawn at diameter of 19 mm.

33. Specimen USNM 130136b.

26-29. Lemuroceras? sp. juv. cf. L. dubium Collignon (p. 110). Specimen USNM 130157, from USGS Mes. loc. 14484. 

34 41. Lemuroceras lalkeetnanum Imlay, n. sp. (p. 109).

34. 37-39. Holotype USNM 130151, from USGS Mes. loc. 24877. Suture line drawn at whorl height of 14 mm.

35. 36, 40, 41. Paratype USNM 130150, from USGS Mes. loc. 24877.
PLATE 19

[Figures natural size unless otherwise indicated] |

FIGURES 1-3. Leconteites lecontei (Anderson) (p. 109).

Plesiotype USNM 130171, from gulch emptying into Hulen Creek a little east of Ono, Calif. Inserted for

comparison with species of Leconteites from Alaska. Note tubercles at umbical edge. 

4-6. Leconteites modestus (Anderson) (p. 109).

4, 5. Plesiotypes USNM 130172, from USGS Mes. loc. 9971.

6. Plesiotype USNM 130173, from USGS Mes. loc. 11389. 

7-14. Leconteites deansi (Whiteaves) (p. 109).

7. 8. Plesiotype USNM 130164a, from USGS Mes. loc. 9972.

12-14. Plesiotype USNM 130164b, from USGS Mes. loc. 9972. Suture line drawn at whorl height of 10.5 mm. 

9-11. Plesiotype USNM 130170, from USGS Mes. loc. 2201. 

15-27. Leconteites cf. L. deansi (Whiteaves) (p. 109).

15. 20, 21. Specimen USNM 130162a, from USGS Mes. loc. 9972.

16. 17. Specimen USNM 130158, from USGS Mes. loc. 14484.

18. Specimen USNM 130169, from USGS Mes. loc. 2201.

19. 23, 24, 27. Four specimens USNM 130174, from USGS Mes. loc. 8872. These show changes in ribbing during 

growth.

22. Specimen USNM 130162b, from USGS Mes. loc. 9972.

25, 26. Specimen USNM 130162c, from USGS Mes. loc. 9972. 

28-32. Aucellinasp. (p. 91).

Both specimens from USGS Mes. loc. 8873.

28-30 Left and right valves and anterior view of both valves of an average-sized specimen, USNM 130167a.

31, 32 Left and right valves of a large specimen, USNM 130167b. 

33-35 Puzosigella cf. P. rogersi (Hall and Ambrose) (p. 108).

Three specimens USNM 130168, from USGS Mes. loc. 8877, show changes in ribbing during growth. 

36-39 Cleoniceras overbecki Imlay, n. sp. (p. 108).

Holotype USNM 130141, from USGS Mes. loc. 9492. Note elongate tubercles at umbilical edge.
GEOLOGICAL SURVEY PROFESSIONAL PAPER 354 PLATE 19

LECONTE1TES, AUCELLINA, PUZOS1GELLA, AND CLEONICERAS