Upper Oligocene–lower-Middle Miocene peramelemorphians from the Etadunna, Namba and Wipajiri formations of South Australia

Abstract

The oldest fossils referable to the marsupial order Peramelemorphia (which includes modern bandicoots and bilbies) stratigraphically date from the upper Oligocene of Australia. Here we describe new ancient peramelemorphian remains from the Etadunna, Namba and Wipajiri formations, which fill gaps in the documented evolutionary history of the clade spanning some 10 million years. The identified taxa include three new species of Bulungu that incorporate the oldest stem peramelemorphian known to date from Faunal Zone A of the Etadunna Formation. We also report a new genus and species of potential thylacomyid, which pushes back the divergence of bilbies by ∼10 million years. Finally, we present a phylogenetic analysis that clarifies the evolutionary relationships of these new taxa with a reassignment of the genus Bulungu to Yaraloidea. Kenny J. Travouillon* [Kenny.Travouillon@museum.wa.gov.au], Western Australian Museum, Collections and Research, 49 Kew Street, Welshpool, Western Australia, 6106, Australia; Robin M. D. Beck [R.M.D.Beck@salford.ac.uk], Ecosystems and Environment Research Centre, School of Science, Engineering and Environment, University of Salford, Manchester, UK; Judd A. Case [jcase@ewu.edu], Department of Biology, Eastern Washington University, Cheney, WA, 99004, USA.