Two new species of Antechinus Macleay (Dasyuridae:Marsupialia) from mid-Pleistocene cave deposits in eastern central Queensland

Abstract

The dasyurid genus Antechinus occurs in numerous Cainozoic fossil sites but until now only one extinct species has been described, Antechinus puteus Van Dyck. Antechinus yammal sp. nov. and A. yuna sp. nov. are described here on the basis of dental remains recovered from middle Pleistocene (between >500 and 205–170 thousand years ago) cave deposits at Mount Etna, eastern central Queensland. Most of these sites are interpreted as closed rainforest palaeoenvironments, and this is the likely habitat of both species. Both taxa are morphologically variable. A. yammal is characterised by complete anterior cingula and well developed posterior cingula on the upper molars; a relatively unreduced, robust P3; and small entoconids. A. yuna is a relatively large species, typified by poorly developed or absent posterior cingula on M1–3, lack of a metacone on M4, and large entoconids on M1–3. Dental morphology suggests that A. yuna was a near relative of the extant A. leo. The dentition of A. yammal shows some similarities to that of A. flavipes, but its exact phylogenetic position is unclear. A. yammal became extinct coincident with the loss of its rainforest habitat some time between 280 and 205–170 thousand years ago. A. yuna survived somewhat longer, but by the late Pleistocene had been replaced by A. flavipes.