Article: The geologically oldest dasyurid, from the Miocene of Riversleigh, north-west Queensland

A new subfamily, genus and species of Dasyuridae is described on the basis of exceptionally well preserved material from the Miocene of Riversleigh, north-west Queensland. Specimens include the only pre-Pleistocene crania known for the family. Barinya wangala gen. et sp. nov. (Barinyainae subfam. nov.) is the geologically oldest taxon that can be placed within Dasyuridae on the basis of synapomorphies that are unequivocal within Dasyuromorphia. Four derived cranial features present in Barinya wangala are shared only with modern Dasyuridae among dasyuromorphians. These are: development of a tympanic process of the pars petrosa to form a distinct periotic hypotympanic sinus; presence of a paroccipital hypotympanic sinus; presence of a deeply invasive sulcus with the posteroventral lip formed by a mesially directed process in the pars petrosa for passage of the internal jugular; and presence of a distinct tubal foramen for passage of the Eustachian tube. Additionally, the following four apomorphies are identified that are found in all modern Dasyuridae, but no other Dasyuromorphia, including Barinya wangala: presence of a fully enclosed stylomastoid foramen that includes a periotic component; contact between the pars petrosa and a paroccipital tympanic process that fully encloses the paroccipital hypotympanic sinus ventrally; extensive dorsal enclosure of the internal jugular canal; and contact between the mastoid tympanic process and the pars petrosa. Barinya wangala represents the sister clade to a monophyletic taxon that includes all extant Dasyuridae. The perception that even basal Dasyuridae may represent morphological approximations of the ancestral australidelphian or dasyuromorphian is strongly refuted.