The thylacine is an extinct carnivorous marsupial that was native to the Australian mainland and the islands of Tasmania and New Guinea. The last known live animal was captured in 1930 in Tasmania. It is commonly known as the Tasmanian tiger (because of its striped lower back) or the Tasmanian wolf (because of its canid-like characteristics). On the Australian mainland, it has been referred as the Nannup tiger.
Various Aboriginal Tasmanian names have been recorded, such as coorinna, kanunnah, cab-berr-one-nen-er, loarinna, laoonana, can-nen-ner and lagunta, while kaparunin is used in the constructed language of Palawa kani.
The thylacine was relatively shy and nocturnal, with the general appearance of a medium-to-large-size canid, except for its stiff tail and abdominal pouch similar to that of a kangaroo. Because of convergent evolution, it displayed an anatomy and adaptations similar to the tiger (Panthera tigris) and wolf (Canis lupus) of the Northern Hemisphere, such as dark transverse stripes that radiated from the top of its back, and a skull shape extremely similar to those of canids, despite being unrelated. The thylacine was a formidable apex predator, though exactly how large its prey animals were is disputed. Its closest living relatives are the Tasmanian devil and the numbat. The thylacine was one of only two marsupials known to have a pouch in both sexes: the other (still extant) species is the water opossum from Central and South America. The pouch of the male thylacine served as a protective sheath, covering the external reproductive organs.
The thylacine had become locally extinct on both New Guinea and the Australian mainland before British settlement of the continent, but its last stronghold was on the island of Tasmania, along with several other endemic species, including the Tasmanian devil. Intensive hunting encouraged by bounties is generally blamed for its extinction, but other contributing factors may have been disease, the introduction of dogs, and human encroachment into its habitat.
Evolution of Thylacine (Tasmanian Tiger)
The modern thylacine probably appeared about 2 million years ago, during the Early Pleistocene. Specimens from the Pliocene-aged Chinchilla Fauna, described as Thylacinus rostralis by Charles De Vis in 1894, have in the past been suggested to represent Thylacinus cynocephalus, but have been shown to either have been curatorial errors, or ambiguous in their specific attribution. The family Thylacinidae includes at least 12 species in eight genera, and appears around the late Oligocene with the small, plesiomorphic Badjcinus turnbulli. Early thylacinids were quoll-sized, well under 10 kg (22 lb), and probably ate insects and small reptiles and mammals, although signs of an increasingly-carnivorous diet can be seen as early as the early Miocene in Wabulacinus.
Members of the genus Thylacinus are notable for a dramatic increase in both the expression of carnivorous dental traits and in size, with the largest species, Thylacinus potens and Thylacinus megiriani both approaching the size of a wolf.
In Late Pleistocene and early Holocene times, the modern thylacine was widespread (although never numerous) throughout Australia and New Guinea.
Description of Thylacine (Tasmanian Tiger)
The only recorded species of Thylacinus, a genus that superficially resembles the dogs and foxes of the family Canidae, the animal was a predatory marsupial that existed on mainland Australia during the Holocene epoch and observed by Europeans on the island of Tasmania; the species is known as the Tasmanian tiger for the striped markings of the pelage. Descriptions of the thylacine come from preserved specimens, fossil records, skins and skeletal remains, and black and white photographs and film of the animal both in captivity and from the field. The thylacine resembled a large, short-haired dog with a stiff tail which smoothly extended from the body in a way similar to that of a kangaroo. The mature thylacine ranged from 100 to 130 cm (39 to 51 in) long, plus a tail of around 50 to 65 cm (20 to 26 in). Adults stood about 60 cm (24 in) at the shoulder and on average weighed 12 to 22 kg (26 to 49 lb), though they could range anywhere from 8 to 30 kg (18 to 66 lb). There was slight sexual dimorphism with the males being larger than females on average. Males weighed in at around 19.7 kilograms (43 lb), and females weighed in at around 13.7 kilograms (30 lb). The skull is noted to be highly convergent on those of canids, most closely remembling that of the red fox.
Thylacines, uniquely for marsupials, have largely cartilaginous epipubic bones with a highly reduced osseous element. This has been once considered a synapomorphy with sparassodonts, though it is now thought that both groups reduced their epipubics independently. Its yellow-brown coat featured 15 to 20 distinctive dark stripes across its back, rump and the base of its tail, which earned the animal the nickname “tiger”. The stripes were more pronounced in younger specimens, fading as the animal got older.
One of the stripes extended down the outside of the rear thigh. Its body hair was dense and soft, up to 15 mm (0.6 in) in length. Colouration varied from light fawn to a dark brown; the belly was cream-coloured.
Its rounded, erect ears were about 8 cm (3.1 in) long and covered with short fur.
The early scientific studies suggested it possessed an acute sense of smell which enabled it to track prey, but analysis of its brain structure revealed that its olfactory bulbs were not well developed. It is likely to have relied on sight and sound when hunting instead.
The thylacine was able to open its jaws to an unusual extent: up to 80 degrees. This capability can be seen in part in David Fleay’s short black-and-white film sequence of a captive thylacine from 1933. The jaws were muscular, and had 46 teeth, but studies show the thylacine jaw was too weak to kill sheep. The tail vertebrae were fused to a degree, with resulting restriction of full tail movement. Fusion may have occurred as the animal reached full maturity. The tail tapered towards the tip. In juveniles, the tip of the tail had a ridge. The female thylacine had a pouch with four teats, but unlike many other marsupials, the pouch opened to the rear of its body. Males had a scrotal pouch, unique amongst the Australian marsupials, into which they could withdraw their scrotal sac for protection.
Thylacine footprints could be distinguished from other native or introduced animals; unlike foxes, cats, dogs, wombats, or Tasmanian devils, thylacines had a very large rear pad and four obvious front pads, arranged in almost a straight line. The hindfeet were similar to the forefeet but had four digits rather than five. Their claws were non-retractable. More detail can be seen in a cast taken from a freshly dead thylacine. The cast shows the plantar pad in more detail and shows that the plantar pad is tri-lobal in that it exhibits three distinctive lobes. It is a single plantar pad divided by three deep grooves. The distinctive plantar pad shape along with the asymmetrical nature of the foot makes it quite different from animals such as dogs or foxes. This cast dates back to the early 1930s and is part of the Museum of Victoria’s thylacine collection.
The thylacine was noted as having a stiff and somewhat awkward gait, making it unable to run at high speed. It could also perform a bipedal hop, in a fashion similar to a kangaroo—demonstrated at various times by captive specimens. Guiler speculates that this was used as an accelerated form of motion when the animal became alarmed. The animal was also able to balance on its hind legs and stand upright for brief periods.
Observers of the animal in the wild and in captivity noted that it would growl and hiss when agitated, often accompanied by a threat-yawn. During hunting, it would emit a series of rapidly repeated guttural cough-like barks (described as “yip-yap”, “cay-yip” or “hop-hop-hop”), probably for communication between the family pack members. It also had a long whining cry, probably for identification at distance, and a low snuffling noise used for communication between family members.
Some observers described it as having a strong and distinctive smell, others described a faint, clean, animal odour, and some no odour at all. It is possible that the thylacine, like its relative, the Tasmanian devil, gave off an odour when agitated.
Distribution and habitatof Thylacine (Tasmanian Tiger)
The thylacine most likely preferred the dry eucalyptus forests, wetlands, and grasslands of mainland Australia. Indigenous Australian rock paintings indicate that the thylacine lived throughout mainland Australia and New Guinea. Proof of the animal’s existence in mainland Australia came from a desiccated carcass that was discovered in a cave in the Nullarbor Plain in Western Australia in 1990; carbon dating revealed it to be around 3,300 years old.
Recently examined fossilised footprints also suggest historical distribution of the species on Kangaroo Island.
In Tasmania it preferred the woodlands of the midlands and coastal heath, which eventually became the primary focus of British settlers seeking grazing land for their livestock. The striped pattern may have provided camouflage in woodland conditions, but it may have also served for identification purposes. The animal had a typical home range of between 40 and 80 km2 (15 and 31 sq mi). It appears to have kept to its home range without being territorial; groups too large to be a family unit were sometimes observed together.
Behaviorof Thylacine (Tasmanian Tiger)
Little is known about the behaviour of the thylacine. A few observations were made of the animal in captivity, but only limited, anecdotal evidence exists of the animal’s behaviour in the wild. Most observations were made during the day, whereas the thylacine was naturally nocturnal. Those observations, made in the twentieth century, may have been atypical, as they were of a species already under the stresses that would soon lead to its extinction. Some behavioural characteristics have been extrapolated from the behaviour of its close relative, the Tasmanian devil.
The thylacine was a nocturnal and crepuscular hunter, spending the daylight hours in small caves or hollow tree trunks in a nest of twigs, bark, or fern fronds. It tended to retreat to the hills and forest for shelter during the day. and hunted in the open heath at night. Early observers noted that the animal was typically shy and secretive, with awareness of the presence of humans and generally avoiding contact, though it occasionally showed inquisitive traits. At the time, much stigma existed in regard to its “fierce” nature; this is likely to be due to its perceived threat to agriculture