|Environment||Kati Thanda and Tarkarooloo Basins|
|Reproduction||Sexual; give live birth|
|Average Weight||29-66 lbs (13-30 kg)|
|Subspecies||Koala, Phascolarctos maris, Phascolarctos yorkensis|
|Related Species||Dropbear, Komala|
Giant Koalas (Phascolarctos stirtoni) were a species of arboreal marsupials that coexisted with the Koala during the Pleistocene epoch, known to have been indigenous to both the Kati Thanda and Tarkarooloo Basins of South Australia. In life, they would have been hard to discern from regular Koalas due to their clear similarities in physical appearance.
Although considered to be the largest tree-dwelling marsupial to have ever lived on Earth, the name "giant" is a bit of a misnomer. Like the Dire Wolf, the Giant Koala was no giant but instead just a more robust creature than the modern-day Koalas they filled the same arboreal niche with. Weighing in at between one-third and twice that of a Koala (29-66 lbs or ~13-30 kg) - the lower end of this scale is the same weight as a typical male koala. Even so, they are still considered to be part of Australia's former megafauna despite not fitting the formal definitions of such.
It is possible that the two species were able to coexist due to eating different food, though it is generally assumed they were folivores that ate Eucalyptus leaves, too.
The Giant Koala went extinct 50,000 years ago. While it is not exactly sure what killed off one species of koala and not the other, hypotheses suggest a sudden change in climate, the restriction of food supply, or selective hunting by the ancestors of Humankind.