Australidelphia
| Australidelphia Temporal range: Early Paleocene to present | |
|---|---|
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| A swamp wallaby | |
Scientific classification  | |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Class: | Mammalia |
| Infraclass: | Marsupialia |
| Superorder: | Australidelphia Szalay 1982 |
| Orders | |
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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. Australidelphia's lineage emerged in South America, with genetic evidence (retrotransposon insertion sites) indicating that the South American monito del monte is sister to all other members of the superorder, unlike other American marsupials, which belong to the Ameridelphia.
Within this superorder, the Australian members form a distinct group (clade) named Eomarsupialia, though their internal relationships (branching order) have yet to be determined. Studies suggest that the Australidelphia originated in South America alongside other major marsupial groups. The Eomarsupialia likely dispersed to Australia via Antarctica in a single event after their divergence from their sister group, the Microbiotheria.