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
Jugulator (mammal) displayed these behaviours. "Jugulator" occurs in the mid-Cretaceous deposits of the Cedar Mountain Formation, where several of North America's more iconic dinosaurs like "Utahraptor" and "Cedarosaurus" occur. A large variety of mammal species are known from here as well, including other eutriconodonts like "Astroconodon" and "Corviconodon" as well as multituberculates like "Cedaromys" and "Janumys" and several therian mammals such as "Montanalestes" and "Atokatheridium". These diverse mammal faunas offer a transition from dominant taxa in the Early Cretaceous and the multituberculate and therian dominated laurasian mammalian faunas of the Late Cretaceous. Jugulator (mammal) Jugulator is a genus of extinct mammal from