The modern koala is the only extant member of Phascolarctidae, a family that once included several genera and species.During the Oligocene and Miocene, koalas lived in rainforests and had less specialised diets. Some species, such as the Riversleigh rainforest koala (Nimiokoala greystanesi) and some species of Perikoala, were around the same size as the modern koala, while others, such as …

