I

" UNIVERSITY OF

3 ILLINOIS LIBRARY

AT URBANACHAMPAIGN

GEOLOGY

ddO.b be^io

^RELDIANA W"^ Geology

Published by Field Museum of Natural History

Volume 35, No. 3 April 29, 1976

Some Notes On

Pennsylvania!! Crustaceans

In the Illinois Basin

FREDERICK R. SCHRAM

department of zoology

Eastern Illinois University, Charleston

and

research associate

field museum of natural history

The malacostracan faunas of the Mazon Creek assemblages have been dealt with in a series of publications (Schram, 1969, 1970, 1973, 1974a, b). This note in the sequence takes up those forms which were not dealt with in those earlier papers and offers a few general comments on the Crustacea of the Mazon Creek assemblages. All specimens referred to are deposited in Field Museum of Natural History.

SYNCARIDS

Two palaeocaridacean syncarids, Acanthotelson stimpsoni and Palae- ocaris typus. Meek and Worthen, 1865, occur in the Pennsylvanian Illi- nois Basin. Both of these species were originally described from the Braidwood Fauna of the Mazon Creek area, Francis Creek Shale, Car- bondale Formation (Westphalian C) (Richardson and Johnson, 1970). In 1885, Packard recognized the distinct nature of these eumalacostracans by erecting the superorder Syncarida to accommodate them, seven years before the first extant form, Anaspides tasmaniae, Thompson, 1893, was discovered in Australia.

Information has come to light to reveal that these syncarids, A. stimp- soni and P. typus, have a wide distribution around the Illinois basin (fig. 1). They are the most common crustaceans in the Mazon Creek Braid- wood Fauna, constituting about 93 per cent of the crustacean forms. But both species are relatively rare elements in the Mazon Creek Essex Fauna, together making up only 5 per cent of the crustaceans. A speci- men of A. stimpsoni was discovered in a well core by the Illinois Geolog-

Library of Congress Catalog Card Number: 76-1206 The Library of tht

Publication 1227 21 NOV 0 9 1976

university ot Illinois r>Cy{. 8t Ufbana-Champaign

22 FIELDIANA: GEOLOGY, VOLUME 35

ical Survey. The specimen, PE 13945, was taken in Wabash County, NW/4, SW/4, SE'/4, sec. 25, T.2 S., R.14 W., at 816 ft. in core T-4, in the Dykersburg Shale, Carbondale Formation above the #5 (Springfield) Coal below the St. David Limestone. Another specimen of A. stimpsoni, PE 13961, was found in a gray shale concretion above the #6 (Herrin) Coal in the Brereton cyclothem, one- half mile west of Carterville in Wil- liamson County, sec. 4, T.9 S., R.l E. A. stimpsoni (P 32083, P 32084) and P. typus (P 32082), are the only crustaceans found to date in the abandoned Chieftain Mine, 7 miles south of Terre Haute, Indiana, east of U.S. Highway 41. This area has been open to amateur collectors for some years and is now largely overgrown with vegetation. The Chieftain locality is in the Lower Shelburn Formation, equivalent to the lower- most Modesto Formation of Illinois, i.e., Pennsylvanian in age but higher in the stratigraphic column than the localities in the Illinois Car- bondale Formation.

There are some physical differences between syncarids found in the Braidwood Fauna and those of the Essex Fauna. Brooks (1962) reported a mean body length of 267 specimens of P. typus (Braidwood specimens) of 2.2 cm., and a mean body length of 176/1. stimpsoni of 2.8cm. In addi- tion, Braidwood specimens are generally characterized by being rather robust and well preserved. I have found that for 35 specimens of P. typus from the Essex fauna for which I could measure body length, the average was 1.9 cm., and for 40 specimens of A. stimpsoni the body length was 2.6 cm. In addition, Essex syncarids are generally poorly preserved. It would thus appear that the more fresh-water ecology represented by the Braidwood assemblage (Richardson and Johnson, 1970) was apparently more conducive to syncarid biology and subsequent preservation.

EOCARIDA

After the publication of my (Schram, 1974a) paper on Mazon Creek caridoids, Mr. Corliss Ingels of Lafayette, Illinois brought a specimen to my attention which has proven to be a new species of the genus Anthra- cophausia (Peach 1908).

Opposite:

Fig. 1. Fossil malacostracan localities of the Pennsylvanian basin (broken line) of Indiana and Illinois. 1, Braidwood fauna of the Mazon Creek area (balloon indicates extent of the localities); 2, Essex fauna of the Mazon Creek area (balloon indicates geographical extent of the localities); 3, Chieftain Mine south of Terre Haute, Vigo Co., Indiana; 4, Ulinois Geological Survey well core T-4 in Wabash Co.; 5, abandoned strip mine talus west of Carterville, Williamson, Co.; 6, Sunspot Mine, north of Astoria, Fulton, Co.

/7)

23

24 FIELDIANA: GEOLOGY, VOLUME 35

Superorder Eocarida Brooks 1962 Order Eocaridacea Brooks 1962 Family Anthracophausiidae Brooks 1962 Genus Anthracophausia Peach 1908 Anthracophausia ingelsorum n. sp.

Diagnosis. — Abdominal pleura rounded; telson with a single median ridge; uropods lobate.

Description. — The holotype and only well-known specimen of A. ingelsorum is 2.25 cm. long from the optic notch of the carapace to the base of the telson. The carapace is 0.82 cm. from optic notch to posterior margin. The rostrum has the marked falciform shape characteristic of the genus and is about 0.26 cm. in length. There is a very slight doublure on the ventral margin of the carapace. Little can be told about the anten- nae and antennules except that they were moderately developed and the antennules had a slight optic groove. No eyes or appendages have been preserved on any of the material at hand.

The first five pleomeres are subequal and have rounded pleura. The sixth pleomere is somewhat longer than any of the other abdominal seg- ments.

The telson is elongate and triangular and has a slight, yet wide median ridge along its dorsal length. It is not clear whether there are caudal fur- cae. The uropods have a simple protopod and thin lobate exopods and endopods.

A reconstruction of Anthracophausia ingelsorum is offered in Figure 2.

Horizon.— Middle Pennsylvanian, Carbondale Formation, Francis Creek Shale.

Fig. 2. Reconstruction of Anthracophausia ingelsorum, scale is 5 mm.

SCHRAM: PENNSYLVANIAN CRUSTACEANS

25

Fig. 3. CEI 41 130, holotype of Anthracophausia ingelsorum, scale is 5 mm.

Locality. — The holotype was collected in the Sunspot Mine just north of Astoria in Fulton County, Illinois (fig. 1), and was found in an iron- stone concretion of the Francis Creek Shale, Carbondale Formation. More poorly preserved specimens have been collected in Peabody Coal Co. Pit 1 1 in Will and Kankakee counties, Illinois, the principal locality of the Mazon Creek Essex Fauna (fig. 1). The Astoria locality has been known for several years to contain fossils characteristic of the Essex as- semblage, though the fauna collected at Astoria is not quite as diverse as that at Pit 1 1 .

Remarks. — Anthracophausia ingelsorum differs from the British Car- boniferous A. dunsiana in that the latter is somewhat larger (with an average carapace length of 1 . 1 cm. from optic notch to posterior mar- gin). A. dunsiana has two longitudinal lobe-like ridges on the dorsal sur- face of the telson, with blade-like uropodal rami; the inner margin of the endopod bears setae.

Holotype.— CE\ 41130, Cooper Museum of Marine Invertebrates, 5012 Pfeiffer Road, Peoria, 111. (to be deposited in Field Museum of Nat- ural History as P 32085).

Etymology. —Named in honor of Corliss and Elva Ingels and their son Eric, Lafayette, Illinois, who found the holotype and are among the many ardent amateur collectors of the Essex Assemblage, in the Peoria area, who have assisted my work through the years.

26 FIELDIANA: GEOLOGY, VOLUME 35

GENERAL COMMENTS

A general assemblage list of the malacostracans found in the Braidwood and Essex faunas is herein presented with approximate relative percentages of each species ("t" means trace or only a few speci- mens known).

Braidwood Fauna Subclass: Eumalacostraca Superorder: Syncarida Order: Palaeocaridacea

Palaeocaris typus Meek and Worthen, 1865 34.2%

Acanthotelson stimpsoni Meek and Worthen, 1865 62.3

Superorder: Eocarida Order: Eocaridacea

Belotelson magister Packard, 1886 t

Superorder: Peracarida Order: Mysidacea

A nthracaris gracilis Meek and Worthen, 1865 3.5

Essex Fauna Subclass: Phyllocarida Order: Archaeostraca

Ceratiocaris sp 26

Dithyrocaris sp 22

Older: Hoplostraca

Kellibrooksia macrogaster Schram, 1973 2.4

Subclass: Hoplocarida

Order: Aeschronectida

Kallidecthes richardsoni Schram, 1969 12.0

Order: Stomatopoda

Tyrannophontes theridion Schram, 1969 1.5

Subclass: Eumalacostraca Superorder: Syncarida

Palaeocaris typus Meek and Worthen, 1865 2.5

Acanthotelson stimpsoni Meek and Worthen, 1865 4.4

Superorder: Eocarida Order: Eocaridacea

Belotelson magister Packard, 1885 65.5

Peachocaris strongi (Brooks) 1962 7.3

Anthracophausia ingelsorum 04

Essoidea epiceron Schram, 1974a 2.0

Superorder: Peracarida Order: Mysidacea

Anthracaris gracilis (Meek and Worthen) 1865 t

Mamayocaris jaskowskii Schram, 1974a 1.0

Order: Tanaidacea

Cryptocaris hootchi Schram, 1974b 3

Order: Isopoda

Hesslerella shermani Schram, 1970 5

SCHRAM: PENNSYLVANIAN CRUSTACEANS 27

The percentages represent a census of crustaceans taken by me over the years in various museums and private collections. The figures should be construed to represent approximate estimates subject to various biases, e.g., the percentage of Belotelson magister may be a little high since this figure also includes some counts of Belotelson exuviae (see Schram, 1974a). The Anthracophausia and Peachocaris are inaccurate since many specimens which were not identifiable as to species probably belonged here and were not counted at all. But the percentages express ratios of specimens that can be tagged with a definite species name.

Two things can be observed, especially with regard to Carboniferous faunas as a whole. First, the Braidwood fauna has a restricted crustacean assemblage of a pygocephalomorph associated with syncarids. The cor- respondence is very striking to what is found in the British Coal Mea- sures where Pygocephalus cooperi (same family as A. gracilis) is asso- ciated with Palaeocaris retractata, Pleurocaris annulatus (structurally similar to A . stimpsoni), and sometimes Praeanaspides praecursor (no apparent counterpart in the Braidwood fauna). We have here the expres- sion of what might be termed a Coal Measure chronofauna consisting of crustaceans which were relatively stable throughout Westphalian time, and which are found in disparate geographic provinces in fresh-water habitats. Associated elements of the faunas include fish, tetrapods, in- sects, arachnids, merostomes, fresh-water clams, in addition to abun- dant plant remains.

Second, the Essex fauna crustaceans are more diverse. They seem to be faunistically continuous and related as a whole (Schram, ms. in prepara- tion) to a separate and distinct near-shore marine chronofauna of crusta- ceans known to extend from Visean through Westphalian time in Europe and North America. The associated fauna of this near-shore marine assemblage includes fish; various soft-bodied invertebrate groups, such as "worms" and coelenterates; various marine molluscs, such as cephalopods; and echinoderms. Plant fossils are relatively rare.

There is some overlap between the two Mazon Creek faunas. Belotel- son magister, the most important shrimp in the Essex fauna, has been found on rare occasion at Braidwood localities. Anthracaris gracilis has a few poorly preserved specimens in Essex localities. Both A. stimpsoni and P. typus comprise a small percentage of Essex crustaceans, and their size and general preservation may indicate that they were attempting to live in conditions marginal for their existence.

In summary, it should be noted that although the Mazon Creek Crustacea form a spectacular assemblage in their own right, their true importance and significance must await the full description and analysis

28 FIELDIANA: GEOLOGY, VOLUME 35

of other Late Paleozoic crustaceans which have come to light since this project started eight years ago.

ACKNOWLEDGEMENTS

I wish to thank the many fossil collectors of the Mazon Creek faunas who have helped me through the years. This includes members of the Earth Science Club of Northern Illinois (ESCONI), the Chicago Rocks and Minerals Society, and the fossil study group of Peoria Academy of Sciences. Special thanks must be extended to Dr. E. S. Richardson, Jr., of Field Museum who was a constant source of enthusiasm and encour- agement. Dr. Tibor Perenyi consulted on illustration techniques in the later papers in this series. My research assistants over the years have offered yeoman service in the cause of Pennsylvanian science; James K. Gilliam, Paul Wilson, Carl Baird, and Linda Catalana. Dr. Murray Copeland and colleagues of the Geological Survey of Canada were of great help in examining material of Paleozoic malacostracans from the Canadian Maritime Provinces. Much of this work has been funded by N.S.F. grant GB-35484 and grants from the Eastern Illinois University Council on Faculty Research.

REFERENCES

Brooks, H. K.

1962. The Paleozoic Eumalacostraca of North America. Bull. Amer. Paleontol., 44, 202 pp. Meek, F. B. and A. H. Worthen

1865. Notice of some new types of organic remains from the Coal Measures of Illinois. Proc. Acad. Nat. Sci. Philadelphia, 18, pp. 46-51. Packard, A. S.

1885. The Syncarida, a group of Carboniferous Crustacea. Amer. Nat., 19, pp. 700-703.

Peach, B. N.

1908. A monograph on the higher Crustacea of the Carboniferous Rocks of Scotland. Geol. Surv. Great Britain, Paleontol. Mem., 1908, 82 pp. Richardson, E. S. and R. G. Johnson

1970. The Mazon Creek faunas. N. Amer. Paleontol. Conv., Chicago, 1969, Proc. I, pp. 1222-1235.

SCHRAM, F. R.

1969. Some middle Pennsylvanian Hoplocarida and their phylogenetic significance. Fieldiana: Geol., 12, pp. 235-289.

1970. Isopod from the Pennsylvanian of Illinois. Science, 169, pp. 854-855.

1973. On some phyllocarids and the origin of the Hoplocarida. Fieldiana: Geol., 26,

pp. 77-94. 1974a. Mazon Creek caridoid Crustacea. Fieldiana: Geol., 30, pp. 9-65. 1974b. Paleozoic Peracarida of North America. Fieldiana: Geol., 33, pp. 95-124. Thomson, G. M.

1893. Notes on Tasmanian Crustacea, with description of new species. Proc. Roy. Soc.

Tasmania, 1892, pp. 45-76.

!

•

■

,

■