Koalas do not belong to the family of bears but were thought to years ago. Ancestors of the koala are thought to have existed about 15 million years ago. Koalas are marsupials, that is the young are born in a very immature state, and are nurtured in a pouch.
Koalas have a distant link only with wombats, both have backward opening pouches.
Most marsupials, including kangaroos and possums have a front opening pouch. Koalas are found only along the eastern coast of Australia. There are approximately 600 varieties of Eucalypt in Australia. After a gestation period of approximately 35 days, a blind hairless cub, about 20 mm long and weighing no more than half a gram, is born. Unaided by the mother it crawls to the pouch using only its forelimbs.