One of the two cohorts into which the Metatheria (marsupials) are often divided. There are five orders: Dasyuromorphia; Diprotodontia; Dromiciopsia; Peramelemorphia; and Syndactyliformes. All except the Dromiciopsia occur in Australia and New Guinea. Because representatives of both cohorts are found in S. America, the hypothesis of a neotropical origin for marsupials (which spread only later into the Australian–New Guinea region and Antarctica) is supported.
Subjects: Zoology and Animal Sciences.