2003-2004 USAP Field Season

Geology & Geophysics

Dr. Rama K. Kotra Program Manager

G-293-M	NSF/OPP 02-29877
Station: McMurdo Station
RPSC POC: Melissa Rider
Research Site(s): Beardmore Glacier, Collinson Ridge, Schroeder Hill, McMurdo Station
Dates in Antarctica: Mid to late November

Shackleton Glacier area: Evolution of vegetation during the Triassic

	Dr. Edith L. Taylor University of Kansas Lawrence Department of Ecology and Evolutionary Biology etaylor@ku.edu

Stem with attached Dicroidium leaves (Late Triassic) from the Shackleton Glacier area.

Deploying Team Members:

Pablo Puerta . David Buchanan . N. Ruben Cuneo . Charles P. Daghlian . Edith L. Taylor . Thomas N. Taylor

Research Objectives: The rocks of the central Transantarctic Mountains have been a source of fossil discoveries over the past 30 years. The rare juxtaposition of sites that include many different types of plant preservation, the exceptional quality of the fossils, and the biodiversity of the sites make this area unique. The Paleozoic to Mesozoic transition is a critical time in plant evolution. A unique variety of seed plant groups existed, and several have been suggested as the ancestors of flowering plants. There was also a massive floral change from the Permian to the Triassic. While most fossil plants occur as disarticulated leaves, stems, and reproductive organs, many in the Shackleton Glacier area are partially articulated, thus making it possible to gain a more accurate picture of the entire plant and its place in the ecosystem. We will examine Triassic floras from two sites in the Shackleton Glacier area (Collinson Ridge and an unnamed ridge southeast of Schroeder Hill). In addition to compression fossils, the latter also includes some permineralized peat and fossil stumps. The Collinson Ridge site is important because it contains fossil peat and logs in presumably Lower Triassic rocks. Preliminary analysis of petrified material collected during the 1995–1996 field season, however, suggests that perhaps it is Late Permian rather than Early Triassic, as would be expected. It is therefore important to elucidate the biostratigraphy of this area because the position of the Permian-Triassic boundary is crucial in understanding the timing of terrestrial extinctions around it. Further collecting at both of these sites and analysis of the fossil material in the laboratory will address these discrepancies and yield important new information about Triassic plant evolution. Paleobotany is ideally suited to education and outreach. Workshops and temporary exhibits on antarctic science have been developed through programs sponsored by the University of Kansas Natural History Museum and Biodiversity Research Center, and we will continue this activity. Student involvement has also been extensive and will be continued.