Mammals of Australia introductions of placental mammals into Australian fauna were about (rats), several thousand years ago (dingo), and 200 years ago (many species); the last two were made by humans. Some claims were made about placental mammal fossils from the Eocene of Australia, called "Tingamarra". These claims are based on only one found tooth having some characteristic features of condylarth, and were discussed widely. But both the age and placental nature of these fossils were challenged by other researchers. Monotremes are mammals with a unique method of reproduction: they lay eggs instead of giving birth to live young. Two of the five
Saint Bathans mammal bat and several currently unclassified species, also existed. Saint Bathans mammal The Saint Bathans mammal is a currently unnamed extinct mammal from the Miocene of New Zealand. A member of the Saint Bathans Fauna, it is notable for being a late surviving "archaic" mammal species, neither a placental or marsupial, as well as for providing evidence that terrestrial mammals did in fact once live in Zealandia, in contrast with modern New Zealand, where bats are the only mammals in otherwise bird-dominated terrestrial faunas. The Saint Bathans mammal is currently represented by two specimens, MNZ S.40958 and MNZ S.42214, composed of