Koala dominant. Older males usually have accumulated scratches, scars, and cuts on the exposed parts of their noses and on their eyelids. The koala's gestation period lasts 33–35 days, and a female gives birth to a single joey (although twins occur on occasion). As with all marsupials, the young are born while at the embryonic stage, weighing only . However, they have relatively well-developed lips, forelimbs, and shoulders, as well as functioning respiratory, digestive, and urinary systems. The joey crawls into its mother's pouch to continue the rest of its development. Unlike most other marsupials, the koala does not clean her
Giant koala Giant koala 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", and has had an estimated weight of , which is the same weight as a large contemporary male koala. 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 goliah", were unambiguously "giants".The