Fauna of New Guinea Guinea. However, the tree-kangaroos, which are mostly endemic to New Guinea, are different in appearance and behaviour. As suggested by their name, they are arboreal. They have long, thick tails which enable them to balance in trees, and large, strong forearms for gripping to trees. Two species of tree kangaroos are also found in Australia, they are believed to have migrated from New Guinea during the Pleistocene. The cuscus, family Phalangeridae, are a family of marsupials closely related to the possums of Australia. The cuscus have evolved in New Guinea, and are found throughout the island. Most species are dark
New Guinea crocodile by the New Guinea Highlands, a mountain range that runs along the centre of the island. DNA analysis has revealed these to be genetically separate populations, and there are some differences in their morphology and behavior. There are estimated to be between 50,000 and 100,000 New Guinea crocodiles in the wild. New Guinea crocodiles have a mostly aquatic lifestyle and are largely nocturnal. They spend much of the day underwater, often with their nostrils and eyes above the surface. Powerful side-to-side movements of their tails propel them through the water and they use both tail and legs to steer. When