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 Worthy et al. 2006 tentatively deemed the Saint Bathans mammal as a theriiform, being more derived than morganucodontans, eutriconodonts and monotremes but not as much as multituberculates, on the basis of its femoral anatomy. As the phylogeny of non-therian mammals has undergone multiple shifts since its description, new studies might be necessary. The Bannockburn Formation depicts a warm temperate or subtropical lakeside environment, surrounded by herbaceous peat–swamps. Casuarinas, araucarias, podocarps, eucalypts, palm trees and southern beeches are among the various plant species known to have grown here. As today, the local vertebrate fauna was dominated by birds: early moas and