Lekaneleo, a new genus of marsupial lion (Marsupialia, Thylacoleonidae) from the Oligocene-Miocene of Australia, and the craniodental morphology of L. roskellyae, comb. nov.

摘要

The domestic cat-sized marsupial lion Priscileo roskellyae (Thylacoleonidae) from the Oligocene-Miocene of Australia was originally allocated to the genus Priscileo Rauscher, 1987, on the basis of its plesiomorphic upper dental formula of three premolars and four molars and its relatively small size. Recent reassignment of the Priscileo type species P. pitikantensis to the genus Wakaleo has now necessitated establishment of a new generic name for the species roskellyae Gillespie, 1997. In contrast to W. pitikantensis, which is only known from a fragmented palate and associated postcranial elements, the skull and lower dentition of P. roskellyae, described here, exhibit features that support its generic distinction within Thylacoleonidae. It is renamed here Lekaneleo roskellyae, comb. nov. Distinctive craniodental features include small sagittal and nuchal crests, lack of a prominent rostral tympanic process on the periotic, lack of alisphenopalatine pterygoid processes, a stylomastoid sulcus that courses through the mastoid, three teeth between i1 and p3, and very broad talonid basins on the lower molars. In contrast to species of Wakaleo, which appear to form a morphocline during the late Oligocene and early Miocene, L. roskellyae is a relatively conservative taxon, exhibiting no discernible change over the same interval of time.