New tertiary koala (Marsupialia, Phascolarctidae) from Riversleigh, Australia, with a revision of Phascolarctid Phylogenetics, Paleoecology, and Paleobiodiversity
KAREN H. BLACK,* MICHAEL ARCHER, and SUZANNE J. HAND
School of Biological, Earth and Environmental Sciences, University of New South Wales, Sydney, New South Wales 2052, Australia,
Here we describe the most plesiomorphic koala yet known. Priscakoala lucyturnbullae , gen. et sp. nov., is the fourth and largest koala species described from Miocene deposits in the Riversleigh World Heritage area, northern Australia. It is known from a maxilla with Ml-3 and isolated M2, M3 or M4 and ml. Relationships within the diprotodontian suborder Vombatiformes are clarified using cranial and dental characters based on a data set compiled from new and more complete cranial materials for each of the respective vombatiform families. Monophyly of Phascolarctidae is supported by the development of a protostylid and metastylid on ml. Priscakoala lucyturnbullae is the most plesiomorphic phascolarctid. Inclusion in the analysis of the enigmatic Pliocene genus Koobor , currently classified as Vombatiformes incertae sedis, indicates phascolarctomorphian affinities for the genus.