A new ¨South American ungulate¨ (Mammalia: Litopterna) from the Eocene of the Antarctic Penisula

BOND, M; REGUERO, M; VIZCAÍNO, S; MARENSSI, S

Cretaceous-Tertiary high-latitude palaeoenvironments, James Ross Basin, Antarctica¨

The Geological Society

Lugar: Londres; Año: 2006; p. 163 - 176

Abstract: Notolophus arquinotiensis, a new genus and species of the family Sparnotheriodontidae(Mammalia, Litopterna), is represented by several isolated teeth from theshallow-marine sediments of the La Meseta Formation (late Early–Late Eocene) ofSeymour Island,Antarctic Peninsula, which have also yielded the youngest known sudamericidsand marsupials. The new taxon belongs to the extinct order of ‘South Americannative ungulate’ Litopterna characterized by the convergence of the later forms with theequids and camelids. Notolophus arquinotiensis shows closest relationships with Victorlemoineafrom the Itaboraian (middle Palaeocene) of Brazil and Riochican–Vacan (latePalaeocene–early Eocene) of Patagonia,Argentina. Although still poorly documented, thisnew taxon shows that the early Palaeogene Antarctic faunas might provide key dataconcerning the problems of the origin, diversity and basal phylogeny of some of the ‘SouthAmerican ungulates’ (Litopterna). This new taxon shows the importance of Antarctica inthe early evolution of the ungulates and illustrates our poor state of knowledge.