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
EDGE species selected each year for which active research and conservation programmes will be carried out. The focal species are the subject of research programmes aimed at establishing what the main threats are and what actions need to be taken to ensure their survival. Each study is focused on delivering a conservation action plan. These plans provide information on the conservation actions highlighted by the research programme, and identify key stakeholders that will carry out these actions. 2007/8 focal mammal species Numbers refer to EDGE rank 2008/9 focal amphibian species EDGE species Evolutionarily Distinct and Globally Endangered (EDGE) species are animal species