BIOL 4141 Chapter : Metatheria Mammology 2014
Document Summary
Introduction: known as marsupials for the marsupium. Introduction: current centers of diversity are the australian region and the neotropics. Paleontology: earliest fossil metatherians from early cretaceous of. Asia: metatherians probably originated in north america, southern continents served as primary centers of metatherian radiations. Paleontology: ancestors of metatherians were insectivorous or omnivorous mammals, may have originated in n. america (laurasia), moved south across s. america, antarctica, Australia (gondwana: south american radiation rivaled that in australia, very few marsupial fossils known from africa. Paleontology convergence w/ eutherians: borhyaenidae convergent with canids and bears, thylacosmilidae convergent with saber-toothed cats, argyrolagidae convergent with kangaroo rats and jerboas. Paleontology: sa was isolated from na until the panamanian land bridge established ~2. 5 million years ago, northern eutherians moved southward, some metatherians moved northward, metatherian diversity begins to decline in s. america. Australian marsupials: many australian species extinct around late pleistocene, fossil metatherians include:
