WOMBAT, the title of the typical representatives of the marsupial family Phascolomyidae (see Marsupialia). They have the dental formula: i. 1, c. 0, p. 2, m. 3, = 24. All the teeth are of continuous growth, having persistent pulps. The incisors are large and chisel-like, much as in rodents. The body is broad and depressed, the neck short, the head large and flat, the eyes small and the tail rudimentary and hidden in the fur. The limbs are equal, stout and short. The feet have broad, naked, tuberculated soles; the forefeet with five distinct toes, each furnished with a long, strong and slightly curved nail, the first and fifth considerably shorter than the other three. The hindfeet have a very short nailless first toe; the second, third and fourth toes partially united by integument, of nearly equal length; the fifth distinct and rather shorter; these four are provided with long and curved nails. In the typical group of the genus Phascolomys we find the following characters:— Fur rough and coarse; ears short and rounded; muzzle naked; post orbital process of the frontal bone obsolete; ribs fifteen pairs. Vertebrae: C. 7, D. 15, L. 4, S. 4, Ca. 10-12. The wombat of Tasmania and the islands of Bass's Straits (P. ursinus) and the closely similar but larger P. platyrhinus of the southern portion of the mainland of Australia, belong to this group. On the other hand, in the hairy-nosed wombat (P. latifrons) of Southern Australia, the fur is smooth and silky; the ears are large and more pointed; the muzzle is hairy; the frontal region of the skull is broader than in the other section, with well-marked post orbital processes; and there are thirteen ribs. Vertebrae: C. 7, D. 13, L. 6, S. 4, Ca. 15-16.
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. They live entirely on the ground, or in burrows or holes among rocks, and feed on grass, roots and other vegetable substances. They sleep during the day, but wander forth at night in search of food, and are shy and gentle, though they can bite strongly when provoked. The only noise the Tasmanian wombat makes is a low hissing, but the hairy-nosed wombat is said to emit a short quick grunt when annoyed. The prevailing colour of the last-named species, as well as P. ursinus of Tasmania, is brownish grey. The large wombat of the mainland is variable in colour, some individuals being pale yellowish brown, others dark grey and some black. The length of the head and body is about 3 ft. Fossil remains of wombats, some of larger size than any now existing, have been found in caves and Pleistocene deposits in Australia. (R. L.*)