These tree-climbing creatures resemble small bears with thick, gray fur that is lighter on the underside of the body. Unlike most marsupials, koalas have only 30 teeth. They have cheek pouches where they temporarily store eucalyptus leaves and an unusual feature called a caecum. The koala was widespread in Australia at the beginning of the 20th century, but its population dwindled as a result of heavy hunting of the animal for its fur. The species is recovering in some areas of Southeastern Australia where it is protected.
Cuscuses live near the equator in the dense tropical forests of New Guinea and neighboring islands.
They are nocturnal creatures with large eyes. The family Petauridae has several species of arboreal possums that include the gliding, ring-tailed, and striped possums. The pygmy possums belong to the family Burramyidae. Wallabies and kangaroos are represented by more than a dozen genera and 50 species in the family Macropodidae. The smallest members in the family belong to the five genera of rat kangaroos, whereas the largest are the members of the genus Macropus, which includes the wallabies, wallaroos, and kangaroos.