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												Thrinaxodon from Graphite Peak, Central Transantarctic Mountains
Thrinaxodon from Graphite Peak, Kenyon in the Cumulus Hills near the Shackleton Glacier, while the other two were from Graphite Peak. central Transantarctic Mountains, The Thrinaxodon maxilla (AMNH number 26101) from Antarctica Graphite Peak under consideration here is a negative impres- sion in very well cemented, siliceous siltstone. A positive latex peel was made for study purposes. The specimen shows the four right incisors typical of galesaurids plus one from the left WILLIAM R. HAMMER side. The right canine and five postcanine teeth are also pre- served. The postcanines show the typical tricuspid pattern of Department of Geology Thrinaxodon liorhinus, with a large central cusp flanked by an- Augtistana College terior and posterior cingulum cusps. The tooth bearing portion Rock Island, Illinois 61201 of the maxilla measures 4 centimeters in length. Posterior to this section the specimen consists of a poorly exposed thin edge of bone that extends for another 3 centimeters. Only the During the 1985-1986 austral summer, vertebrate specimens ventral edge of the right mandible is exposed, because its dor- were collected from both the late Early to early Middle Triassic sal portion is overlapped by the maxilla. upper Fremouw Formation (Hammer 1990; Hammer, Collin- Overall the specimen shows no features that would make it son, and Ryan 1990) and the Early Scythian (earliest Triassic) a new species of Thrinaxodon. It is, however, very fragmentary, lower Fremouw Formation (Hammer et al. 1986; Hammer 1989) and hence, it is only questionably referred to Thrinaxodon lior- in the Beardmore Glacier region. The primary vertebrate lo- hinus. calities in the lower member of the formation in this area were This research was supported by National Science Founda- Coalsack Bluff and Graphite Peak (see Hammer 1989; Hammer tion grants DPP 85-11334, DPP 86-14140, and DPP 84-18428 to 1990). - 
												
												11.2 Supporting Information - #19
11.2 Supporting Information - #19 EARLY CRETACEOUS UPLIFT OF THE SOUTHERN SENTINEL RANGE, ELLSWORTH MOUNTAINS, WEST ANTARCTICA P. G. FITZGERALD and E. STUMP Department of Geology, Arizona State University, Tempe, Arizona 85287, USA Abstract: Apatite fission track analysis of a 4.2 km vertical profile of samples collected from the western flank of the southern Sentinel Range indicates unroofing (uplift and erosion) in excess of 4 km between -140 and 117 Ma following the initial separation of East and West Gondwana and accompanying the opening of the Weddell Sea. A single apatite age (169 ± 17 Ma) from the Heritage Range indicates less uplift there during the Early Cretaceous, but suggests that Early Cretaceous uplift was initiated between -145 and -169 Ma. The amount of uplift and denudation in the southern Sentinel Range since the Early Cretaceous is unlikely to have been more than 3 km and was probably much less. At least 1.8 km of relief has persisted there since the Early Cretaceous. Key words: Ellsworth Mountains, Sentinel Range, uplift, fission track Introduction analysis towards the resolution of the uplift history of the In contrast to East Antarctica, a stable remnant of the Ellsworth Mountains. Samples were collected from the Gondwana supercontinent, West Antarctica is composed of western flank of the Sentinel Range, notably from Vinson at least five crustal blocks, separated from each other by Massif. Unfortunately, logistic problems severely restricted deep sub-ice basins and troughs that may represent areas of the full extent of sampling and precluded any work in the rifting and extension, and possibly floored by either oceanic Heritage Range. - 
												
												Field Collection for Apatite Fission Track Analysis, Ellsworth Mountains
Hammer, W.R. 1990. Triassic terrestrial vertebrate faunas of Antarc- New vertebrates from the Fremouw formation (Triassic) Beard- tica. In T.N. Taylor and E.L. Taylor (Eds.), Antarctic paleobiology. more Glacier region, Antarctica. Antarctic Journal of the U.S., 21(5), New York: Springer-Verlag. 24-26. Hammer, W.R., J.W. Collinson, and W.J. Ryan, III. 1990. A new Trias- Seeley, H.G. 1894. Researches on the structure, organization and clas- sic vertebrate fauna from Antarctica and its depositional setting. sification of the fossil Reptilia. Part IX, section 1: On the Therosuchia. Antarctic Science, 2(2), 163-167. Philosophical Transactions of the Royal Society of London, series B, 185, Hammer, W.R., W.J. Ryan, J.W. Tamplin, and S.L. DeFauw. 1986. 987-1,018. Field collection for apatite fission track 85°W analysis, Ellsworth Mountains EDMUND STUMP and PAUL C. FITZGERALD Department of Geology Arizona State University Tempe, Arizona 85287-1404 We collected rock samples for fission track analysis in the Ellsworth Mountains during the 1989-1990 austral summer to provide an understanding of the tectonic history of this crustal block. In broader terms, the study will attempt to relate the Figure 2 uplift history of the Ellsworth Mountains to the tectonic evo- lution of West Antarctica. Because the put-in date was delayed, we had to abbreviate the original field plan, which included collections in the Her- ,-Nunatak .690± itage Range (figure 1). We were put in on 21 November 1989 Bastien Hills 5 kilometers west of Mount Gardner in the central Sentinel 79°S Minisa (aCU " Range (figure 2). - 
												
												Gazetteer of the Antarctic
NOIJ.VQNn OJ3ON3133^1 VNOI±VN r o CO ] ] Q) 1 £Q> : 0) >J N , CO O The National Science Foundation has TDD (Telephonic Device for the Deaf) capability, which enables individuals with hearing impairment to communicate with the Division of Personnel and Management about NSF programs, employment, or general information. This number is (202) 357-7492. GAZETTEER OF THE ANTARCTIC Fourth Edition names approved by the UNITED STATES BOARD ON GEOGRAPHIC NAMES a cooperative project of the DEFENSE MAPPING AGENCY Hydrographic/Topographic Center Washington, D. C. 20315 UNITED STATES GEOLOGICAL SURVEY National Mapping Division Reston, Virginia 22092 NATIONAL SCIENCE FOUNDATION Division of Polar Programs Washington, D. C. 20550 1989 STOCK NO. GAZGNANTARCS UNITED STATES BOARD ON GEOGRAPHIC NAMES Rupert B. Southard, Chairman Ralph E. Ehrenberg, Vice Chairman Richard R. Randall, Executive Secretary Department of Agriculture .................................................... Sterling J. Wilcox, member Donald D. Loff, deputy Anne Griesemer, deputy Department of Commerce .................................................... Charles E. Harrington, member Richard L. Forstall, deputy Henry Tom, deputy Edward L. Gates, Jr., deputy Department of Defense ....................................................... Thomas K. Coghlan, member Carl Nelius, deputy Lois Winneberger, deputy Department of the Interior .................................................... Rupert B. Southard, member Tracy A. Fortmann, deputy David E. Meier, deputy Joel L. Morrison, deputy Department