References sequence exposed in the central and southern Heritage Range. The trilobite-mollusk fauna continues to yield im- portant new forms. Calyx plates of unknown pelmatozoans Colbert, Edwin H., andJames W. Kitching. 1977. Triassic cynodont have been recovered and represent at least two species. The reptiles from Antarctica. American Museum Novitates, 2611 fauna includes probably the best preserved and most diverse 1-30. Late Cambrian mollusks known. Twenty species of mollusks Estes, Richard. 1961. Cranial anatomy of the cynodorit reptile are present representing the four molluscan classes: Thrinaxodon lzorhtnus. Bulletin of the Museum of Comparative Monoplacophora, Hyolitha, Gastropoda, and Rostrochon Zoology, Harvard College, 125: 165-180, pls. 1, 2. - chia. In addition, forms transitional to the Cephalopoda are Jenkins, Farish A., Jr. 1971. The postcranial skeleton of African present. -- cynodonts. Peabody Museum of Natural History, Bulletin, 36: i-x, 1-216. Monoplacophora are the dominant molluscan forms and are represented by several genera and 10 new species. Gastropoda are represented by four species referable to the Macluritacea. Hyolitha are represented by four species referable to Hyolithus, Contitheca, and Ort hot heca. Rostrochonchja are represented by two species referable to Riberta and to a new genus and mark the first antarctic oc- Paleontological investigations in currence of these forms. Protoconchs and early growth the Ellsworth Mountains, West stages of various mollusks indicate some radical changes in shell shape during ontogeny and in some cases a complete Antarctica reversal of shell curvature. The great diversity of mollusks along with a very diverse trilobite fauna and other faunal elements which include ar- GERALD F. WEBERS chaeocyathids, articulate and inarticulate brachiopods, and pelmatozoans, is indicative of a mild environment— Department of Geology probably tropical. Macalester College The environment of deposition of the fauna appears to St. Paul, Minnesota 55105 have been shallow marine and possibly littoral. The mollusks are the best preserved with protoconchs and early Antarctic faunas from the Heritage Range (centered at growth stages preserved. Archaeocyathids are invariably 79 0S. 85 0W.) of the Ellsworth Mountains, including a new broken cylindrical forms only rarely preserving the early Late Cambrian trilobite fauna collected by a Norwegian ex- growth stages. Presumably they were broken from their at- pedition in the 1975-1976 austral season, have been under tachments and transported to their resting sites. Trilobites study. Despite the relatively small number of rock specimens are disarticulated predominantly adult stages and were collected, several new species are present. This fauna is probably also transported. The early growth stages as well as stratigraphically close to a previously reported prolific every other growth stage (with some forms as large as 8 cen- trilobite-mollusk fauna (Webers, 1972) and promises addi- timeters) of the Monoplacophora, together with their ex- tional fossil faunas in the thick (10,000 meters) stratigraphic cellent preservation, indicate that they dominated the shallow, nearshore environment, perhaps with a sprinkling of other faunal elements. There appears to have been a marked period of adaptive radiation for the mollusks in the Late Cambrian of Antarc- tica. The diversity of molluscan forms argues for adaption to a variety of life styles within the shallow water marine en- vironment. Monoplacophorans probably include forms adapted to rock clinging and detritus feeding. One unusual monoplacophoran, Knightoconus antarcticus (Yochelson et al., 1973) is a precephalopod marking a direction toward pelagic capabilities. The various representatives of the Hyolitha perhaps also represent swimming forms. The presence of the Rostroconchia with their anterior and posterior siphons indicates an infaunal adaption (Runnegar and Pojeta, 1974). It thus appears that the Late Cambrian of West Antarctica marked a period of adaptive radiation of the mollusks. This rapid diversication appears to have oc- curred in tropical (perhaps littoral to sublittoral) en- vironments. Somewhat later in the Late Cambrian this molluscan radiation is represented in the north-central United States. The diversity of forms is somewhat less, but the fauna still occupied the shallow marine littoral to sublit- Steinkern of an antarctic Rostroconch, new genus and toral environment and lived under tropical conditions. species, from the north central Heritage Range of the This research was supported by National Science Founda- Ellsworth Mountains, 4X. tion grant P3V-0036.

120 ANTARCTIC JOURNAL References genera nonmarine dispersal routes between Africa, India and western Australia can account for the distribution. Cosmopolitan distribution of Mesozoic conchostracan genera in the southern continents including Antarctica is at- Runnegar, B., and J Pojeta, Jr. 1974. Molluscan phylogeny: the . tributed to continental ligature or proximity. By contrast paleontological viewpoint. Science, 186: 311-317. the conchostracan speciation program was restricted to local Unusual Upper Cambrian fauna from West Webers, G.F. 1972. in Antarctica. Antarctic Geology and Geophysics. Universitet- or regional situations (isolated lakes or ponds) (Tasch, forlaget, Oslo, 235-237. press). Yochelson, EL., R.H. Flower, and G.F. Webers. 1973. The bear- This research was supported by National Science Founda- ing of the new Late Cambrian monoplacophoran genus tion grant OPP 73-05831. Knightoconus upon the origin of the Cephalopoda. Lethaza, 6: 275-310. References

Tasch, P. In press. Crustacean branchiopod distribution and specia- Intercontinental correlation by tion in Mesozoic lakes of the southern continents. In: Antarctic Research Series (B.C. Parker, ed.). conchostracans and Tasch, P., and P.M. Oesterlen. 1977. New data on the "Phyllopod Beds" (Karroo System) Northern Angola. South Central palynomorphs from Antarctica, Geological Society America, Annual Meeting (El Paso). Abstracts western Australia, India, and with program: 77. Africa

PAUL TASCH Palynomorph preservation in the Department of Geology Wichita State University Beacon Supergroup of the Wichita, Kansas 67208 Transantarctic Mountains

All three Tasch stations at Carapace Nunatak were found ROSEMARY A. KYLE to have the components of Balmes Exesipollenites Assemblage from the Perth and Carnarvon Basins of Institute of Polar Studies western Australia (Jurassic, probably late Liassic). Excellent palynomorphs were recently recovered from a few Storm JAMES M. SCHOPF Peak samples (lower interbed, Tasch stations 0 and 1). Residues were good to massive. This contrasts with the Institute of Polar Studies and general situation of palynomorph- barren beds in both lower Department of Geology, and upper interbeds at Storm Peak, These new data will be The Ohio State University reported by P. Tasch and J.M. Lammons at the Interna- Columbus, Ohio 43210 tional Palynological Colloquium, Leon, Spain in September 1977. A paper with T.J. Jones on the "Conchostracan fauna of Flat-lying sedimentary rocks of the Early Devonian to Ear- the Carboniferous and Triassic of the Canning Basin" is be- lyjurassic Beacon Supergroup occur throughout the Trans- ing readied for publication by the Bureau of Mineral antarctic Mountains. Several workers (e.g. Schopf, 1962; Resources (CS I RO, Canberra, Australia). Besides descrip- Norris, 1965; Helby and McElroy, 1969; Kemp, 1972; Kyle, tion of the fauna, findings suggest a post-Carboniferous in press) have experienced difficulty in extracting dispersal of ribbed conchostracan eggs from Canning Basin recognizable palynomorphs from Beacon rocks. The poor of western Australia to the Bowen Basin and the Newcastle preservation or absence of palynomorphs is attributed to Coal Measures belt in eastern Australia. Permian ribbed thermal metamorphism during the intrusion of the Jurassic conchostracans from the Ohio Range, have long since been Ferrar Group dolerite sills and extrusion of the comagmatic shown to correlate with equivalents in the Newcastle Coal Kirkpatrick Basalt. This igneous activity has also resulted in Measures. the carbonization of plant cuticles and woody material, the Correlation of nonmarine deposits of the Karroo System semi-anthracite rank of the Permian and Triassic coal, and "Phyllopod Beds" (Northern Angola) and those of the the formation of zeolites typical of low grade metamor- Triassic Panchet Formation (Raniganj Basin, India) has phism. been strengthened by discovery of three conchostracan Over 500 samples from the Beacon Supergroup of the genera common to both formations: Estheriina, Cornia, Transantarctic Mountains have been processed for Paleolimnadia (Tasch and Oesterlen, 1977). Since the palynological study. In some areas (e.g., southern Victoria Triassic of the Canning Basin has species of two of these Land and the Nilsen Plateau, Queen Maud Mountains) only

October 1977 121