Didelphimorphia
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Oppossum, or Possum
Didelphimorphia is the order of common opossums of the Western Hemisphere. Opossums probably diverged from the basic South American marsupials in the late Cretaceous or early Paleocene. A sister group is Paucituberculata (shrew opossums). They are commonly also called "possums," though that term is also applied to Australian fauna of the suborder Phalangeriformes. The Virginia Opossum is the original animal named "opossum". The word comes from Algonquian wapathemwa. Colloquially, the Virginia opossum is frequently called simply possum.