The family Thylacinidae comprises only one species, the thylacine or tasmanian wolf (Thylacinus cynocephalus). Following the arrival of Europeans, the thylacine developed a reputation for killing sheep, and hunting and epidemic disease appear to have brought about its extinction. There have been no official sightings of this animal since the last thylacine in captivity died in Hobart Zoo in 1936.

Fossils show that the thylacine lineage arose about 15 millions years ago. The thylacine's dental and pedal morphology was unlike any other Australian marsupial and it is presumed to be a sister group to the dasyurids.

The thylacine was the largest of recent marsupials, weighing between 15 and 35 kg. It was a nocturnal animal, tending to feed in woodland and grasslands and nesting in dense forests on hilly terrain. Thylacines were thought to have hunted alone or in pairs, preying upon wallabies, possums, bandicoots, rodents and birds.

Superficially thylacines resembled dogs, about 60 cm high at the shoulder, with a dog-like head, short neck, short legs and a long stiff tail. Sandy yellow in colour, they had brown/black stripes across the back. They ran on diagonally opposing limbs, sat upright on their tail and hindlimbs like a kangaroo, and could leap 2 - 3 metres high.

Thylacine skull

Wolf skull

The thylacine's long-snouted skull shows remarkable evolutionary convergence with the skulls of wolves and dogs but closer inspection reveals typical marsupial features.

• Thylacines have a relatively small brain case compared to the wolf
• The thylacine's dental formula is I4/3; C1/1; PM3/3; M4/4
• The wolf's dental formula is I3/3; C1/1; PM4/4; M3/3;
• Thylacines lack the carnassial tooth of wolves and dogs;
• The thylacine skull has palatal vacuities, like skulls of primitive mammals;
• Wolf and dog skulls lack palatal vacuities.

Bandicoots	Dasyurids	Marsupial moles
Koala	Wombats
Kangaroos	Possums	Feathertail or pygmy glider