Classification
Domain: Eukarya
Kingdom: Animalia
Phylum: Chordata
Class: Mammalia
Infraclass: Marsupialia
Order: Diprotodontia
Family: Phascolarctidae
Genus: Phascolarctos
Species: Phascolarctos cinereus
The classification above is the classification for the koala.There were once several different kinds of koala - all but one of which had died out. Those species you can see on the cladogram bellow.
Kingdom: Animalia
Phylum: Chordata
Class: Mammalia
Infraclass: Marsupialia
Order: Diprotodontia
Family: Phascolarctidae
Genus: Phascolarctos
Species: Phascolarctos cinereus
The classification above is the classification for the koala.There were once several different kinds of koala - all but one of which had died out. Those species you can see on the cladogram bellow.
Cladogram
Though related to wombats and kangaroos, koalas (Phascolarctos cinereus) are thought to have been always been koalas and not evolved from another animal. They only have one known homologous structure, or a structure that serves no function that suggests evolution (that it was used at one time.) This is their "vestigial tail", which is similar to a humans tail bone. This is highly debated though, as some suggest that it does serve a function as it aids koalas sitting in trees.
Related animals
As previously stated, koalas are related to wombats and kangaroos. They are also related to opossums and wallabies. These are all marsupial mammals, and are all native to Australia (expect for the opossum).Also the name koala bear is actually incorrect because koalas aren't bears at all. Koalas are marsupials so they are closely related to other animals like kangaroos and wombat. The closest living relative to the koala is the wombat. Kangaroos and wombats are a part of the Diprotodontia order which is common for marsupials. They share the pouch that they carry their young in and they also share how they take care of their young. These characteristics are common for marsupials.
Species That They live with
There are many other animals that share the same ecosystem as koalas. Some animals that prey on Koalas are Dingoes, Red foxes, quolls, goannas, and the green python. Most of these animals live on the ground so they can only prey on koalas when they are on the ground and since koalas can protect themselves some prey can only prey on sick, weak, or young koalas. Some birds also share the koala's habitat. These birds are wedge-tailed eagles, emus and barking owls. These are some but not all the animals that live with koalas.