Giant_koala
Giant koala
Extinct species of marsupial
The giant koala (Phascolarctos stirtoni) is an extinct arboreal marsupial which existed in Australia during the Pleistocene epoch. Phascolarctos stirtoni was about one-third larger than the contemporary koala, P. cinereus,[2] and has an estimated weight of 13 kg (29 lb), which is the same weight as a large contemporary male koala.[3]
Although considered a part of the Australian megafauna, its body mass excludes it from most formal definitions of megafauna. It is better described as a more robust koala, rather than a "giant"; in contrast, a number of Australian megafauna, such as Diprotodon and Procoptodon, were unambiguously giants, even if not compared to their closest relatives.
The two koala species co-existed during the Pleistocene, occupying the same arboreal niche.[2] The reason for the extinction of the larger of the two about 50,000 years ago is unknown, although there are various hypotheses for their extinction.