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

ABSTRACT

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.

ACKNOWLEDGMENTS

Support for research at the Riversleigh WHA has come from the Australian Research Council grants to M. Archer, S. Hand, and K. Black (DP1094569, LP100200486, DP130100197, DE130100167, DP170101420), P. Creaser and the CREATE Fund, K. and M. Pettit, the University of New South Wales, Environment Australia, Queensland Parks and Wildlife Service, Outback at Isa, Mount Isa City Council, and the Waanyi people of northwest Queensland. For kindly allowing access to specimens, we would like to thank A. Yates and G. Dally of the Museum and Art Galleries of the Northern Territory, N. Pledge, J. McNamara and M. Binnie of the South Australian Museum, and R. Jones of the Australian Museum. We thank H. Godthelp, K. Black, and T. Myers for careful and expert preparation of Riversleigh fossils. We thank J. Muirhead for her preliminary drawings. We thank the many enthusiastic volunteers who have contributed to Riversleigh research in the field and in the laboratory. We thank K. Black for providing helpful comments on a draft of the manuscript. We are also grateful to P. Brewer and anonymous reviewers for suggestions that improved the manuscript.