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
New Guinea species with origins in Asia, together with typically Australasian flora. Typical Southern Hemisphere flora include the conifers "Podocarpus" and the rainforest emergents "Araucaria" and "Agathis," as well as tree ferns and several species of "Eucalyptus". New Guinea has 284 species and six orders of mammals: monotremes, three orders of marsupials, rodents and bats; 195 of the mammal species (69%) are endemic. New Guinea has 578 species of breeding birds, of which 324 species are endemic. The island's frogs are one of the most poorly known vertebrate groups, totalling 282 species, but this number is expected to double or even triple