First gondwanatherian mammal from Antarctica

GOIN, F; REGUERO M,; PASCUAL, R; VON KOENISWALD, W; WOODBURNE, M; CASE, J; MARENSSI, S; VIEYTES, C; VIZCAÍNO, S

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

The Geological Society

Lugar: Bath; Año: 2006; p. 134 - 144

Abstract: Gondwanatherians are an enigmatic group of extinct non-therian mammalsapparently restricted to some of the western Gondwanan continents (Late Cretaceous–early Palaeocene of South America, and Late Cretaceous of Madagascar and India). Theydeveloped rodent-like incisors and the earliest known hypsodont cheek-teeth amongmammals. Recently, a small rodent-like dentary fragment was recovered from middleEocene beds on the Antarctic Peninsula, preserving part of the incisor; both the incisorenamel structure and the mandibular morphology suggest close affinities with Sudamericaameghinoi from the early Palaeocene of Patagonia, up to now the youngest known Gondwanatheria.Thus, the new specimen becomes the youngest occurrence of a gondwanathere,adding significant direct and indirect evidence on: (1) the already documented cosmopolitanismof gondwanatheres among Gondwanan mammals; and (2) the crucial biogeographicalrole of Antarctica during the Cretaceous–Tertiary mammalian transition.