Polydolopimorphia

Polydolopimorphia is an extinct order of metatherians, more closely related to extant marsupials than other extinct mammals. Known from the Paleocene-Pliocene of South America and the Eocene of Antarctica, they were a diverse group during the Paleogene, filling many niches, before declining and becoming extinct at the end of the Neogene. It is divided into two suborders, Bonapartheriiformes, and Polydolopiformes Most members are only known from jaw fragments, which have their characteristically generally bunodont teeth. The morphology of their teeth has led to proposals that polydolopimorphians may be crown group marsupials, nested within Australidelphia, though this proposal, and the monophyly of the order as a whole has been questioned, with other analyses finding them outside of crown-group Marsupialia. The group contained omnivorous, frugivorous and herbivorous forms.