Immediately before European settlement, the Australian mainland fauna included about 320 species of land mammals comprising 3 monotremes, 174 marsupials, 75 bats, 67 native rodents and the dingo. Extinction has been uneven among the groups. While the bats have suffered no extinctions, many non-volant species in a critical weight range (CWR) between 35 and 5,500 grams adult body weight have either become extinct or are endangered. CWR insectivorous marsupials have generally survived better. Native rodents, except for members of the genus Rattus, have been particularly badly affected. The extinction was very rapid, and continues because the main threatening processes (feral cats and foxes) remain. A consequence of the speed of extinction was that the majority of populations of susceptible species disappeared before they were sampled by collectors, and several originally widespread extinct species are only known from very few live-caught specimens. At least 7 species with restricted ranges were never collected alive at all. Sites containing late Holocene mammal remains are abundant in Australia, with >740 in the western two-thirds; most are caves in karst limestone or desert mesas and ranges, but also sand dunes and tree hollows. The main accumulators were owls. Mammalian predators also contributed. Remains reveal that many now extinct or endangered species originally had vast geographic ranges. Understanding of the ecology of many Australian native mammals, and the communities of which they were members, can only be achieved by studying their remains using multivariate analyses incorporating correlations with surviving species with known ecological requirements.