The koala or, inaccurately, koala bear is an arboreal herbivorous marsupial native to Australia. It is the only extant representative of the family Phascolarctidae and its closest living relatives are the wombats, which are members of the family Vombatidae. The koala is found in coastal areas of the mainland's eastern and southern regions, inhabiting Queensland, New South Wales, Victoria, and South Australia. It is easily recognisable by its stout, tailless body and large head with round, fluffy ears and large, spoon-shaped nose. The koala has a body length of 60–85 cm (24–33 in) and weighs 4–15 kg (9–33 lb). Fur colour ranges from silver grey to chocolate brown. Koalas from the northern populations are typically smaller and lighter in colour than their counterparts further south. These populations possibly are separate subspecies, but this is disputed.
Diprotodontia is an order of about 155 species of marsupial mammals including the kangaroos, wallabies, possums, koala, wombats, and many others. Extinct diprotodonts include the hippopotamus-sized Diprotodon, and Thylacoleo, the so-called "marsupial lion".
Obdurodon is a genus of extinct monotreme. They appeared much like their modern day relative the platypus, except adults retained their molar teeth. Unlike the platypus which forages on the lakebed, Obdurodon may have foraged in the water column or surface.
The order Peramelemorphia includes the bandicoots and bilbies; it equates approximately to the mainstream of marsupial omnivores. All members of the order are endemic to the twin land masses of Australia-New Guinea and most have the characteristic bandicoot shape: a plump, arch-backed body with a long, delicately tapering snout, very large upright ears, relatively long, thin legs, and a thin tail. Their size varies from about 140 grams up to 4 kilograms, but most species are about one kilogram, or the weight of a half-grown kitten.
Bandicoots are a group of more than 20 species of small to medium-sized, terrestrial marsupial omnivores in the order Peramelemorphia. They are endemic to the Australia–New Guinea region, including the Bismarck Archipelago and, marginally, in Indonesia (Seram).
The Phascolarctidae is a family of marsupials of the order Diprotodontia, consisting of only one extant species, the koala, and six well-known fossil species, with another five less well known fossil species, and two fossil species of the genus Koobor, whose taxonomy is debatable but are placed in this group. The closest relatives of the Phascolarctidae are the wombats, which comprise the family Vombatidae.
The Vombatiformes are one of the three suborders of the large marsupial order Diprotodontia. Seven of the nine known families within this suborder are extinct; only the families Phascolarctidae, with the koala, and Vombatidae, with three extant species of wombat, survive.
Thylacinidae is an extinct family of carnivorous, superficially dog-like marsupials from the order Dasyuromorphia. The only species to survive into modern times was the thylacine, which became extinct in 1936.
Thylacoleonidae is a family of extinct meat-eating marsupials from Australia, referred to as marsupial lions. The best known is Thylacoleo carnifex, also called the marsupial lion. The clade ranged from the Late Oligocene to the Pleistocene, with some species the size of a possum and others as large as a leopard. As a whole, they were largely arboreal, in contrast to the mostly terrestrial dasyuromorphs, monitor lizards and mekosuchines.
Palorchestes is an extinct genus of terrestrial, herbivorous marsupials of the family Palorchestidae. The genus was endemic to Australia, living from the Miocene through to the Pleistocene epochs.
Ekaltadeta is an extinct genus of marsupials related to the modern musky rat-kangaroos. Ekaltadelta was present in what is today the Riversleigh formations in Northern Queensland from the Late Oligocene to the Miocene.
Nimbadon is an extinct genus of the family Ilariidae, from the suborder Vombatiformes, and order Diprotodontia that lived from the Late Oligocene to the Miocene epoches. Many fossils have been found in the Riversleigh World Heritage property in north-western Queensland.
The Riversleigh rainforest koala is an extinct marsupial, closely related to the extant koala, that inhabited northwestern Queensland in the early-middle Miocene. Along with species of sister genus Litokoala, the Riversleigh rainforest koala is the smallest representative of family Phascolarctide. Based on cladistic analysis, Nimiokoala is one of the more basal genera of Phascolarctide. It died out due to climate change rendering the environment more arid. It probably had a more generalized diet than that of the modern species, but its exact food preferences are unknown.
The Macropodidae are an extant family of marsupial with the distinction of the ability to move bipedally on the hind legs, sometimes by jumping, as well as quadrupedally. They are herbivores, but some fossil genera like Ekaltadeta are hypothesised to have been carnivores. The taxonomic affiliations within the family and with other groups of marsupials is still in flux.
Priscakoala is an extinct genus of koala from the Early Miocene of Riversleigh, Australia.
Perikoala is an extinct genus of marsupials, related to the modern koala. The genus diverged from a common ancestor of the other koala genera Nimiokoala, Litokoala, and Phascolarctos, which contains the living koala.
Ekaltadeta ima is a species of potoroid marsupial that existed in Miocene Australia.
Propalorchestes is a fossil genus of Diprotodontidae, mammals that existed in Australia.
Madakoala was a genus of extinct phascolarctid marsupials with only three known subspecies, Madakoala devisi,Madakoala wellsiandMadakoala robustus, and seven sister species, Invictokoala, Koobor, Litokoala, Nimiokoala, Perikoala, Phascolarctos, and Priscakoala with only Phascolarctos having an extant species. Madakoala went extinct around 280,000 years ago in the Pleistocene epoch.
Koobor was a genus of extinct phascolarctid marsupials. It has two sub-species and they are Koobor jimbarratti and Koobor notabillis. And it has seven sister-species, they are Invictokaola, Madakoala, Litokoala, Nimiokoala, Perikoala, Phascolarcto, and Priscakoala with only Phascolarctos having an extant species.
