Neogene vegetation of the Meyer Desert Formation (Sirius Group) Transantarctic Mountains, Antarctica Allan C. Ashworth a, * , David J. Cantrill b a Department of Geosciences, North Dakota State University, Fargo, ND 58105-5517, USA b Department of Palaeobotany, Swedish Museum of Natural History, Box 50007, SE-104 05, Stockholm, Sweden Received 5 November 2003; received in revised form 28 May 2004; accepted 2 July 2004 Abstract A tundra vegetation consisting of at least 18 plant species is described from the Meyer Desert Formation which outcrops along the Beardmore Glacier in the Transantarctic Mountains, about 500 km from the South Pole. The fossils include pollen, seeds, fruits, flowers, leaves, wood, and in situ plants, of which wood and leaves of Nothofagus and a pollen assemblage had been previously reported. The plants include a cryptogamic flora of mosses and liverworts, conifers, and angiosperms in the families Gramineae, Cyperaceae, Nothofagaceae, Ranunculaceae, Hippuridaceae, ?Caryophyllaceae, and ?Chenopodiaceae or ?Myrtaceae. The plants grew in a weakly-developed soil formed within a complex periglacial environment that included moraines, glacial outwash streams, well-drained gravel ridges, and poorly drained depressions in which peat and marl were being deposited. D 2004 Elsevier B.V. All rights reserved. Keywords: Antarctica; Neogene; Nothofagus ; Palaeoecology; Biodiversity; Palaeoclimate 1. Introduction The Antarctic flora today is dominated by crypto- gams, most of which only grow in the most sheltered coastal locations north of 658S. Only two species of vascular plants are known, a grass Deschampsia antarctica Desv. (Poaceae) and a herbaceous caro- phyllid, Colobanthus quitensis (Kunth.) Bartl (Car- yophyllaceae). Both species occur in the area from the islands of the Scotia Ridge, along the west coast of the Antarctic Peninsula south to the current southernmost site on Alamode Island, Terra Firma Islands at 68842VS. On the eastern side of the Antarctic Peninsula, adjoining the frozen Weddell Sea, vascular plants extend only as far south as 658 (Kappen and Schroeter, 2002). Both D. antarctica and C. quitensis are considered to have colonized the Antarctic Peninsula during the Holocene. Convey (1996) felt that the main reason why only two species had successfully invaded was because of the geographic isolation of Antarctica. The asymmetry in the geo- 0031-0182/$ - see front matter D 2004 Elsevier B.V. All rights reserved. doi:10.1016/j.palaeo.2004.07.002 * Corresponding author. Fax: +1 701 231 7149. E-mail address: allan.ashworth@ndsu.nodak.edu (A.C. Ashworth). Palaeogeography, Palaeoclimatology, Palaeoecology 213 (2004) 65– 82 www.elsevier.com/locate/palaeo