Australia is best known for its iconic mammals, the kangaroos, poossums and koala. These are just the tip of the iceberg though, and Australia has a very diverse mammal fauna. Many of the mammals are secretive and rarely seen, being nocturnal or living in remote areas of the arid Outback. As far as mammals are concered, Australia holds an unfortunate record - the worst rate of mammal extinction in modern history. Introduced feral predators such as the Eurasian fox and domestic cats have taken a terrible toll of the native mammals, which by and large were not adapted to cope with mammalian predators. A huge and costly effort has been made to re-establish populations of mammals in protected areas of the mainland, but sadly the fox and cat are now in Australia to stay. Ironically, the same problem has happened in New Zealand, where an introduced Australian mammal, the Brush-tailed Possum, has wreaked havoc among native mammals, birds, and vegetation.
Marsupials are the most famous mammals in Australia, and are the most diverse group of mammals across the continent. They range from the tiny Pygmy Possums to the largest of all, the Red Kangaroo, which can stand taller than a grown man.
Monotremes are egg-laying mammals. The most famous is the platypus, but the echidna is more frequently seen.
Pinnipeds are the seals and sea lions (and walruses in the Northern hemisphere).