Australia is inhabited by at least if o different species of marsupials, which is about two-thirds of the known species; these have been arranged in five tribes, according to the food they eat, viz., the grass-eaters (kangaroos), the root-eaters (wombats), the insect-eaters (bandicoots), the flesh-eaters (native cats and rats), and the fruit-eaters (phalangers).
As regards the teeth, in all cases except the wombats the number of upper incisors differs from that of the corresponding lower teeth.
In general form and action wombats resemble small bears, having a somewhat similar shuffling manner of walking, but they are still shorter in the legs, and have a broader and flatter back.
Fossil remains of wombats, some of larger size than any now existing, have been found in caves and Pleistocene deposits in Australia.
There seems to be no doubt that fossilized remains of the dingo occur intermingled with those of the extinct Australian mammals, such as giant kangaroos, giant wombats and the still more gigantic Diprotodon.