Fossil lobsters from , from 20 sites spanning this boundary, thus providing an excel- lent opportunity to examine the effects of the presumed Cre- taceous/Tertiary (K/T) boundary event. Furthermore, numerous lobsters were collected for the first time from the overlying, Paleocene age, Sobral Formation. Although final analysis of the specimens has not been undertaken, preliminary field observa- tions suggest that the decapods did not experience a major RODNEY M. FELDMANN extinction at this time. Instead, the new species, tentatively referred to Mefanephrops, appears near the base of unit 10, in Department of Geology association with a diverse assemblage of ammonite Kent State University cephalopods, and continues into the Sobral Formation. Kent, Ohio 44242 Hoploparia stokesi has also been identified above, as well as below, the KIT boundary. During the examination of decapods from the Lopez de Ber- todano Formation, it was noted that different regions of lobster skeletons were selectively preserved (Feldmann and Tshudy 1987). Approximately 45 percent of the specimens, collected in Examination of the decapod crustacean fauna of Seymour 1983-1984, were anatomically incomplete; invariably the ab- Island, , has been in progress during the dominal region was absent. Feldmann and Tshudy (1987) spec- past 4 years. During the field season of 1983-1984, several ulated that selective scavenging by cephalopods may have been specimens of fossil lobsters were collected from the Late Cre- responsible for this phenomenon. These results will be retested taceous Lopez de Bertodano Formation. Examination of these by detailed examination of the large sample of fossil lobsters organisms has resulted in the refinement of the description of collected during 1986-1987; however, preliminary results seem Hoploparia stokesi Weller, a species previously described from to suggest that the same general relationships will be observed. sites on (Ball 1960) and noted on Seymour Thus, the collection of numerous macrurous decapod crusta- Island (del Valle and Rinaldi 1975). Additionally, a single lobster ceans from sites within the James Ross Basin has extended the specimen was collected and referred to Linuparus, a genus pre- geographic range of decapods throughout the basin and has viously reported from the Southern Hemisphere at a single site extended their stratigraphic range into the Paleocene as well. in Africa (Tshudy and Feldmann in press). Diversity of decapods seems to increase near the K/T boundary. As a result of these preliminary investigations, it was recog- Taxa occurring in uppermost Cretaceous rocks also occur in nized that there was a strong potential for further enhancement overlying Paleocene rocks. The lobsters appear to be unaffected of our understanding of decapods in the Antarctic. Therefore, by the presumed K/i boundary event. Although processes of during the 1986-1987 field season, extensive collections of fossil selective predation and scavenging seem to affect the preserva- decapods were made. More than 440 specimens were collected tion potential of different anatomical parts of lobsters, pre- from sites on Seymour Island and adjacent James Ross, Vega, served on Seymour Island, the area stands as one in which Humps, Cockburn, and Snow Hill islands (figure 1). decapods are unusually abundant. Comments regarding the significance of specimens collected The field work for this study was supported by a National from the adjacent islands are premature, except to note that Science Foundation grant to William J. Zinsmeister and labora- decapods previously have not been reported from Vega, tory work was supported by National Science Foundation grant Humps, Cockburn, or Snow Hill islands. However, several DPP 84-11842 to Feldmann. (This article is Contribution 358, general conclusions can be drawn based upon specimens col- Department of Geology, Kent State University, Kent, Ohio lected from Seymour Island. 44242.) Whereas brachyuran decapods—crabs--have been noted to be abundant and diverse in the Eocene La Meseta Formation of Seymour Island (Feldmann and Zinsmeister 1984; Feldmann 1985), none has been collected in the subjacent units. Instead, the decapod fauna in the Cretaceous and Paleocene rocks con- sists entirely of macrurans—lobsters. Decapod crustaceans are generally common throughout the upper units, units 7 through 10, of the Lopez de Bertodano References Formation. These units are known as the molluscan units (Mac- ellari 1986). Invariably, the specimens are found in concretions. Ball, H.W. 1960. Upper Cretaceous Decapoda and Serpulidae from Diversity and numerical abundance of lobsters seems to in- James Ross Island, Graham Land. Falkland Islands Dependencies Survey crease upward in the section. At the lowermost localities, in unit Scientific Reports, 24,1-30. 7, Hoploparia stokesi (figure 2) is the only species represented. del Valle, R., and C.A. Rinaldi. 1975. Sobre la presencia de Hoploparia Above that, however, Linuparus n. sp. and a second new spe- stokes, (Weller) en las "Snow Hill Island Series," de la Isla Vice- cies, possibly referable to the genus Metanephrops, occur in comodoro Marambio, Antartida. (Contribucion del Instituto Antar- association with H. stokesi. tico Argentino, Contribucion No. 190.) The rocks of the Lopez de Bertodano Formation range in age Feldmann, R.M. 1985. Decapod crustaceans from the Late Cretaceous from Campanian to Paleocene (Macellari 1986). The boundary and the Eocene of Seymour Island, Antarctic Peninsula. Antarctic Journal of the U.S., 19(5),4-5. between the Cretaceous and Tertiary occurs within unit 10, the Feldmann, R.M., and D. Tshudy. 1987. Ultrastructure in cuticle from uppermost unit of the formation, and has been considered to Hoploparia stokesi (Decapoda: Nephropidae) from the Lopez de Ber- occur within a sequence containing several glauconite beds todano Formation (Late Cretaceous-Paleocene) of Seymour Island, (Macellari 1986). Nearly 100 fossil lobsters have been collected Antarctica. Journal of Paleontology, 61(6);1194-1203.

1987 REVIEW 11 Surf icial Deposits

;en Telm&7 fe LA MESETA 1dm 1r5 FORMATION 1dm 3 (EOCENE) ::.:.:.. Tel 1-2

Tpcv 1-5 CROSS VALLEY FORMATION Tps 4 • E PALEOCENE) 13 AL FORMATION ______rpss 3 l-2 ALEOCENE)

LOPEZ DE BE RIO 0 AND FORMATION ETACEoue-. lLEOCENE)

M. Cs • DECAPOD SITE

Figure 1. Location maps showing the position of sites from which macrurous decapod crustaceans have been collected in the Lopez de Bertodano and Sobral formations. The geological map and stratigraphic section are adapted from Sadler (in press) and are reproduced with his permission. ("KIT" denotes "Cretaceous/Tertiary.")

12 ANTARCTIC JOURNAL

Feldmann, R.M., and W.J. Zinsmeister. 1984. Fossil crabs (Decapoda: Brachyura) from the La Meseta Formation (Eocene) of Antarctica: Paleoecological and biogeographic implications. Journal of Paleon- tology, 58(4), 1046-1061. Macellari, C.E. 1986. Late Campanian-Maastrichtian ammonite fauna from Seymour Island (Antarctic Peninsula). Journal of Paleontology, Vol. 60, (The Paleontological Society Memoir 18, Part 2.) Sadler, P.M. In press. Geometry and stratification of Paleogene and latest Cretaceous units on Seymour Island, northern Antarctic Penin- -j sula. In R.M. Feldmann and M.O. Woodburne, (Eds.), Geology and paleontology of Seymour island, Antarctica. (Geological Society of Amer- ica Memoir 169.) Tshudy, D., and R.M. Feldmann. In press. Macrurous decapod crusta- ceans, and their epibionts, from the Lopez de Bertodano Formation (Late Cretaceous), Seymour Island, Antarctica. In R.M. Feldmann and M . O. Woodburne, (Eds.), Geology and paleontology of Seymour Island, Antarctica. (Geological Society of America Memoir 169.)

Figure 2. Hoploparia stokesi Weller. Latex cast of a specimen from the Lopez de Bertodano Formation, preserved as a molted, but complete, carapace and abdomen. (Bar scale equals 1 centimeter.)

Palynological investigations of the cysts, acritarchs) palynomorphs and documentation of their distribution patterns. The dinocyst assemblages have proved James Ross Island basin, Antarctica particularly useful for biostratigraphy (Askin in press), and the land plant-derived spores and pollen should add useful infor- mation on climatic evolution of the area. Unlike terrestrial sedi- ROSEMARY A. ASKIN ments, which can contain palynomorphs of relatively local deri- vation, the mainly nearshore marine sediments of Seymour Island contain spores and pollen transported from a wide range Department of Earth Sciences University of California of terrestrial habitats and microclimates. Thus these as- Riverside, California 92521

During December 1986 and January 1987, additional sam- Vega Island AAfarctica pling of Campanian to Eocene sediments was carried out for palynological study in the James Ross Island basin (figure), northeastern Antarctic Peninsula. The 300 samples collected are Naze (J mainly from Seymour Island and cover certain intervals of 640 interest in more detail than was previously available. Data from c::; Island these samples will refine and extend the palynomorph zonation 9 5 10 15 20 Km proposed for the upper Campanian to Paleocene part of the VUIO succession (Askin in press). Parts of the upper Lopez de Ber- I) Point todano Formation, including the glauconitic interval that spans I Cockburn James Ross Island ( the Cretaceous/Tertiary boundary, and parts of the Eocene La Island Meseta Formation were sampled. Short helicopter-supported visits also were made to three Hamilton nearby islands to collect from ?Campanian sections. The three Seymour sampled localities are Cockburn Island, Humps Island, and Ula Island Point on eastern James Ross Island (figure). Fossil palynomorphs are ubiquitous in the Seymour and nearby island sedimentary succession and occur, often abun- EPateogene sediments Snow Hill Island dantly, in all 935 samples processed to date. It is expected that Cretaceous sediments the newly collected samples also will be productive, bringing [] the samples available for this study to a total of over 1,200. The present phase of this project includes taxonomic descrip- Locality map for the James Ross Island basin. ("Km" denotes tion of nonmarine (spores, pollen) and marine (dinoflagellate "kilometer?")

1987 REVIEW 13