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
Mammal Species of the World In its Annual Report for 2015, the Committee noted that it is under contract with Johns Hopkins Press for the 4th edition of MSW, which will be edited by DeeAnn M. Reeder and Kristofer M. Helgen. The database has been made editable for the authors, leading to more frequent website updates. The publication was due in 2017. Mammal Species of the World Mammal Species of the World: A Taxonomic and Geographic Reference is a standard reference work in mammalogy giving descriptions and bibliographic data for the known species of mammals. It is now in its third edition, published in late