Australidelphia

Australidelphia is a superorder of marsupials encompassing about three-quarters of all living marsupial species, including all those native to Australasia and one South American species, the monito del monte. Unlike other American marsupials, which belong to the Ameridelphia, Australidelphia's lineage emerged in South America, with genetic evidence (retrotransposon insertion sites) showing the monito del monte as its most ancient branch.

thumb|Comparison of isolated tarsals of Djarthia murgonensis with an extant australidelphian marsupial and an extant non-australidelphian ('ameridelphian') marsupial