Diprotodontia

VombatiformesPhalangeriformesMacropodiformes Diprotodontia (/daɪˌproʊtəˈdɒntiə/, from Greek "two forward teeth") is the largest extant order of marsupials, with about 155 species,[2] including the kangaroos, wallabies, possums, koala, wombats, and many others.

A few insectivorous and omnivorous diprotodonts are known, and the Potoroidae are almost unique among vertebrates in being largely fungivorous, but these seem to have arisen as relatively recent adaptations from the mainstream herbivorous lifestyle.

[citation needed] Many of the largest and least athletic diprotodonts (along with a wide range of other Australian megafauna) became extinct when humans first arrived in Australia about 50,000 years ago.

Members of the order are, first, "diprotodont" (meaning "two front teeth"): they have a pair of large, procumbent incisors on the lower jaw, a common feature of many early groups of mammals and mammaliforms.

Syndactyly is not particularly common (though the Australian omnivorous marsupials share it) and is generally posited as an adaptation to assist in climbing.

The prominent mandibular central incisors characteristic of the diprotodonts are evident in this Kangaroo Island western grey kangaroo ( Macropus fuliginosus fuliginosus )