The thylacine was a large carnivorous marsupial, now extinct, with the last known specimen dying in captivity in 1936. The earliest thylacine record is dated at about 4 million years ago, and the animal was once widespread over mainland Australia and Papua New Guinea as well as Tasmania. In more recent times it was restricted to Tasmania, having become extinct elsewhere more than 2,000 years ago.
The thylacine was yellowish-brown, dog-like in appearance, and had characteristic dark stripes across its back extending from near the shoulders onto the tail base. The stripes were more pronounced on younger animals because they faded with age. Its common name, Tasmanian tiger, refers to its striped back. It was also sometimes called Tasmanian wolf. Thylacine fur was short, soft and dense, and up to 15 mm in length.
The thylacine had a long body, comparatively short legs, a thick stiff tail, and a head that was wolflike or doglike (which 'cynocephalus' implies). Adults were 100-180 cm long from nose to tail tip, about 60 cm high at the shoulder, and weighed 20-30 kg. Females were generally smaller than males. They had strong jaws that could be opened remarkably wide. Thylacine footprints were distinctive and featured a very large foot pad with obvious toe pads. Its claws were not retractable.
The thylacine was the largest carnivorous marsupial of recent times, feeding on wallabies, kangaroos, birds and other small animals. Following colonisation, it reportedly preyed upon sheep and poultry. The thylacine was mainly nocturnal and hunted alone or in pairs within their 40-80 sq km home range. They moved relatively slowly in a stiff awkward manner, and probably captured prey using ambush tactics or by pursuing them to exhaustion.
Thylacine breeding season was during winter and spring although there may have been some limited breeding throughout the year. Following birth, the tiny hairless young crawled into the mother's pouch, and attached themselves to one of four teats. Litters of up to four, although usually two or three, were carried in the pouch for up to three months. When old enough to leave the pouch, they were left in a lair in a cave, nest or hollow log while the mother hunted.
Hunting by colonists was probably the leading cause of the thylacine's extinction. The Tasmanian government paid a bounty on each scalp. However, other factors such as competition from introduced dogs, disease and habitat fragmentation probably contributed to the thylacine's rapid decline and eventual extinction.
The Tasmanian government provided for the protection of the thylacine in July 1936, less than two months before the last known thylacine died in captivity in Hobart Zoo on 7 September 1936. It is now officially listed as extinct by the international conservation organisation IUCN. It is the only mammal to become extinct from Tasmania since British colonisation. Although there have been many alleged sightings, there is no reliable evidence for the continued existence of the species.
Scientists from the Australian Museum in Sydney have applied modern genetic techniques in an attempt to clone new thylacine individuals. However, the project was terminated due to a conclusion that it would not be possible to obtain a complete DNA sequence.