Glossopteris flora in the Permian Weller Formation of Allan Hills, South Victoria Land, Antarctica: Implications for paleogeography, paleoclimatology, and biostratigraphic correlation

Abstract

The Permo-Triassic Victoria Group in South Victoria Land, Antarctica, is a heterogeneous sequence of glacial tillite beds, carbonaceous and non-carbonaceous fluvial deposits, and volcaniclastic strata. The carbonaceous beds are rich in plant fossils associated with coal seams. In Antarctica, the geological record of the Late Paleozoic Ice Age is restricted to the Early Permian. After deglaciation, the Glossopteris flora thrived in polar forests in Antarctica throughout the Permian but disappeared at the end-Permian extinction. Here we describe the first comprehensive record of the Glossopteris flora from the Permian Weller Formation of Allan Hills, South Victoria Land, Antarctica. The flora is well preserved and comprises pteridophytes and gymnosperms. The pteridophytes include the sphenopsid order Equisetales and the gymnosperms comprise Glossopteridales. Equisetales are represented by branched and unbranched axes, whereas, Glossopteridales are highly diverse encompassing Gangamopteris, Glossopteris, Surangephyllum, sterile scale leaves namely Scirroma sp., Nautiyalolepis sp., Utkaliolepis indica, Scale leaf A and scale leaf of male fructification Eretmonia. The flora of the Weller Formation shows close similarity with the Late Permian assemblages of India, South Africa and Australia. Gangamopteris, an index fossil of the Early Permian formations of different Gondwana continents, had extended stratigraphic range in the Late Permian Weller Formation of Allan Hills. Antarctica played a crucial role in the dispersal of Glossopteris flora because of its central position in Gondwana.