The numbat (Myrmecobius fasciatus), is a marsupial widespread across southern Australia. The numbat is an emblem of Western Australia and protected by conservation programs.
Numbats were formerly found across southern Australia from Western Australia across as far as northwestern New South Wales. However, the range has declined significantly since the arrival of Europeans, and the species has survived only in two small patches of land in the Dryandra Woodland and the Perup Nature Reserve, both in Western Australia. In recent years, it has, however, been successfully reintroduced into a few fenced reserves, including some in South Australia and New South Wales.
Numbats breed in February and March, normally producing one litter a year, although they can produce a second if the first is lost. The young are 2 centimetres long at birth, and crawl to the teats, and remain attached until late July or early August, by which time they have grown to 7.5 centimetres. They first develop fur at 3 centimetres, and the adult coat pattern begins to appear once they reach 5.5 centimetres. After weaning, the young are initially left in a nest, or carried about on the mother's back, and they are fully independent by November.
Source: en.wikipedia.org/wiki/Numbat - 07.12.2011
With their birth the cubs of the Numbat are indeed similarly unfinished as with the other Marsupials, but it has no sac for them.