part of the season, Elizabeth Vrba of Yale University, thor- New vertebrates from the Fremouw oughly searched exposures of: (1) the Fremouw Forma- Formation (Triassic) tion (all localities except 11 listed in figures 1 and 2; (2) the Beardmore region, Buckley Formation (figure 1 localities 2 and 3; figure 2 localities 5, 9, 13, and 15) and; (3) the type section of the Falla Formation at Mount Falla (figure 2, locality 11). W.R. HAMMER, W.J. RYAN, and J.W. TAMPLIN Although the Buckley and Falla Formations lacked bones, five of the Fremouw localities yielded well-preserved vertebrate Department of Geology material. Two of the fossil sites, Coalsack Bluff and Graphite Augustana College Peak (figures 1 and 2), were previously known vertebrate lo- Rock island, Illinois 61201 calities from the 1969-1970 and 1970-1971 seasons when groups headed by E.H. Colbert (1969-1970) and James Kitching Si. DEFAuw (1970-1971) collected in this area (Colbert 1970, 1971; Kitching et al. 1972). The other three, Willey Point, Lamping Peak, and Department of Biological Sciences Gordon (figures 1 and 2), are new localities discovered Wayne State University 1985-1986. Detroit, Michigan 48202 In past seasons, the lower 200 meters of the Fremouw Forma- tion has been particularly productive of vertebrate material. During the austral summer of 1985-1986, over 350 specimens Elliot, Collinson, and Powells (1972) report on the stratigraphy of fossil vertebrates were recovered from sections in the of the -bearing beds at Coalsack Bluff indicated fossil area of the . The bones were recovered from the lower 90 meters of the section. field collecting team, which included all of the authors and, for Kitching et al. (1972) noted that all of the specimens collected

Figure 1. Map of portions of the Dufek and Shakleton Coasts, Central Transantarctic Mountains. Localities searched: 1, exposures along the Tillite Glacier; 2, Willey Point; 3, Graphite Peak; 4, exposures along the Koski Glacier. (Inset represents area covered by figure 2.)("km" denotes "kilometer.")

24 ANTARCTIC JOURNAL

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Figure 2. Map of the area near the Beardmore South Camp (represents an enlargement of inset from figure 1). Localities searched: 5, Mount Sirius; 6, unnamed ridge adjacent to Mount Sirius; 7, unnamed nunatak near Bauhs Nunatak; 8, unnamed ridges between Mount Sirius and Coalsack Bluff; 9, Coalsack Bluff; 10, Gordon Valley; 11, Mount Falla; 12, Fremouw Peak; 13, Lamping Peak; 14, exposures along the ; 15, exposures along the . ("km" denotes "kilometer.")

during the 1970-1971 season were found within the first 200- partial skull. Other material recovered pertains to a new therio- meter interval. With the exception of the fragmentary dont and a larger reptile, perhaps a thecodont similar to that postcranial remains of a small reptile 239 meters above the reported by Cosgriff (1983). Smaller reptiles in the assemblage formational base (Cosgriff 1978), the 1977-1978 collection also probably include procolophonids and eosuchians. derives from the lower 200 meters. The composite fauna repre- The lower Fremouw localities also produced an abundance of sented by the three previous collections is large and varied labyrinthodont material, including fragments of brachyopid, (Colbert 1982; Hammer and Cosgriff 1981), and establishes lydekkerinid, capitosaurid(?), and rhytidosteid dermal ele- close correlation between the lower Fremouw Formation of Ant- ments. Some of this material may be assignable to taxa already arctica and the zone of South (Colbert 1972, described from the Antarctic (Colbert and Cosgriff 1974; Cos- 1982; Kitching et al. 1972; Hammer and Cosgriff 1981). griff and Hammer 1983, 1984), however, at least one or two Four of the five localities (all except Gordon Valley) quarried forms new to the continent are included in this assemblage. during the 1985-1986 season yielded a wide variety of spec- Because these lower Fremouw fossils occur in a variety of depo- imens from similar Lystrosaurus zone equivalents in the lower sitional environments this collection has excellent potential for 200 meters of the Fremouw Formation. Individual specimens taphonomic and paleoecological analysis. from the lower portion of the formation range from skulls and The fifth vertebrate locality, in the Gordon Valley (figure 2), is disarticulated postcranial elements to partial skeletons. In- of particular importance because stratigraphically it is consider- cluded in this collection are fossils representing many of the ably higher in the section than the other vertebrate sites (Collin- previously reported Fremouw taxa (Colbert 1982) plus several son and Isbell, Antarctic Journal, this issue); hence it represents species new to the Antarctic. Excellent specimens of the first major occurrence of vertebrates in the upper member of Lystrosaurus were found, including a relatively large partial skel- the Fremouw Formation. Labyrinthodonts, including at least eton with a skull. is represented by jaws and a one very large form (estimated skull length 0.75 meter), are well

1986 REVIEW 25 preserved and abundant here. Jaws and partial skulls of synap- Colbert, E.H. 1982. Triassic vertebrates in the Transantarctic Mountains. sids also occur, including a fairly large theriodont. Little of the In M. Turner and J. Splettstoesser (Eds.), Geology of the central Transan- material was well exposed in the field so more specific tax- tarctic Mountains. Antarctic Research Series, 39(2). Washington, D.C.: onomic determinations are difficult to make at this time, American Geophysical Union. however, the size and general nature of these animals indicate Colbert, E.H., and J.W. Cosgriff. 1974. Labyrinthodont amphibians that, in many cases, they do not appear to represent forms from Antarctica. American Museum Novitiates, 2552, 1-30. Collinson, J.W., and J Isbell. 1986. Permian-Triassic sedimentology of typical of the Lystrosaurus zone. They occur considerably higher . the Beardmore Glacier region. Antarctic Journal of the U.S., 21(5). in the section, hence, it is not unlikely that they are somewhat Cosgriff, J.W. 1983. Large thecodont reptiles from the Fremouw Forma- younger in age than the fossils of the lower Fremouw. Whatever tion. Antarctic Journal of the U.S., 18(5), 52-55. their age, these animals represent species new to the fauna of Cosgriff, J.W., and W.R. Hammer. 1983. The labyrinthodont amphibi- the Fremouw Formation. ans of the earliest Triassic from Antarctica, Tasmania and South We wish to thank members of the support crew and other Africa. In R.L. Oliver, P.R. James, and J.B. Jago, (Eds.) Antarctic Earth science projects at the Beardmore South camp for their help in science. Canberra: Australian Academy of Science. the field. A particular thanks goes to Elizabeth Vrba, for her Cosgriff, J.W., and W.R. Hammer. 1984. New material of labyrinthodont contributions to our field party. amphibians from the Lower Triassic Fremouw Formation of Ant- This project was supported by National Science Foundation arctica. Journal of Vertebrate Paleontology, 4(1), 47-56. grants DPP 85-11334 and DPP 84-18354. Cosgriff, J.W., W.R. Hammer, J.M. Zawiskie, and N.R. Kemp. 1978. New Triassic vertebrates from the Fremouw Formation of the . Antarctic Journal of the U.S., 13(4), 23-24. References Elliot, D.H., J.W. Collinson, and J.S. Powell. 1972. Stratigraphy of Tri- assic tetra pod-bearing beds of Antarctica. In R.J. Adie (Ed.), Antarctic geology and geophysics. Oslo: U niversitetsforlaget. Colbert, E.H. 1970. The fossil of Coalsack Bluff. Antarctic Hammer, W.R., and J.W. Cosgriff. 1981. Myosaurus gracilis, an anomo- Journal of the U.S., 5(3), 57-61. d()nt reptile from the Lower Triassic of Antarctica and . Colbert, E. H. 1971. Triassic tetrapods from McGregor Glacier. Antarctic Journal of Paleontology, 55(2),410-424. Journal of the U.S., 6(5), 188-189. Kitching, J.W., J.W. Collinson, D.H. Elliot, and E.H. Colbert. 1972. Colbert, E. H. 1972. Antarctic tetrapods. In Second Gondwana Lystrosaurus zone (Triassic) fauna from Antarctica. Science, 175(4021), Symposium, South Africa, 1970. 524-526.

trunk (1.0 meter diameter, 13.5 meters long) occurred within a Paleoenvironment of Lower Triassic few meters and at the same stratigraphic level as the isolated plants from the Fremouw Formation blocks. The blocks represent large chunks of heterogeneous peat that were rafted and eventually buried in the stream. The directions T.N. TAYLOR, E.L. TAYLOR, and J.W. COLLINSON of trough axes in the sandstone appear to have been deflected around the blocks during deposition, suggesting that the blocks were grounded in shallow water. The abundance of silicified Institute of Polar Studies Ohio State University plant material at this horizon and the lack of any preserved Columbus, Ohio 43210

During the 1985-1986 field season, collections of silicified plant remains were made from a site located in a col north of -! Fremouw Peak, , central Transantarctic Mountains (84°16S 164°21E) Buckley Island Quadrangle (Bar- rett and Elliot 1973). The fossil plant locality occurs in the upper Fremouw Formation, a braided stream deposit of early-to-mid- dle Triassic age. The fossils occur within several allochthonous clasts that are at approximately the same stratigraphic level within a trough-crossbedded, medium-grained, greenish-gray -4r volcaniclastic sandstone. The clasts are block shaped; the largest was 1.0 meter thick and 2.5 x 2.5 meters in width (figure 1). The lower 0.4 meter consisted of light gray mudstone that I graded upward into a silicified, dark gray, carbonaceous I mudstone with abundant plant remains. Another block (0.5 meter thick, 1.5 x 2.0 meters wide) and a large silicified tree , ... Figure 1. Section through clast showing heterogeneous silicified plant material on top, with dark gray mudstone immediately below Dr. E.L. Taylor was formerly E.L. Smoot. (arrow), and lighter mudstone at base (x 4).

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