Thylacine

Tasmanian wolf or Tasmanian tiger: Neither wolf nor tiger

The name Tasmanian wolf might be misleading, as that animal was neither a wolf nor did it resemble one. Rather, its physique was more similar to a dog or dingo; with shorter front legs than hind legs, the thylacine even resembled a cat or hyena in this respect.

In fact, the thylacine was a marsupial, as female animals had a pouch on their abdomen in which they carried their young. Inside the pouch were two pairs of teats, so a female thylacine could have a maximum of four offspring. The lifespan of these animals is estimated today at 12 to 14 years.

Tasmanian thylacines could reach a shoulder height of about 60 centimeters and a weight between 15 and 30 kilograms. They had short gray to yellowish-gray fur, and the 13 to 19 dark transverse stripes on the rear part of their body also gave them names such as Tasmanian tiger or zebra dog.

The thylacine should not be confused with the Tasmanian devil (Sarcophilus harrisii), which still exists today on Tasmania. It too was intensively hunted until the 1930s. The extinct thylacine is only distantly related to the Tasmanian devil.

Thylacines were once widespread on the Australian continent and in New Guinea, as evidenced by Aboriginal rock paintings. However, they went extinct in New Guinea and on the Australian mainland, with the most recent fossils dated around 3000 BC. A possible cause for their disappearance could be the introduction of the dingo (Canis lupus dingo), a domestic dog gone feral around 5,000 years ago. The dingo might have displaced the thylacine through increased competitive pressure. On the island of Tasmania at the southern tip of Australia, where dingoes were absent, we at least know for certain that thylacines survived until 1936.

Thylacine – Fact sheet

Alternative name	Thylacinus, Tasmanian wolf, Tasmanian tiger, Tassie tiger, marsupial wolf, zebra dog, pouched wolf, marupial dog, (dobsegna) etc.
Scientific name	Thylacinus cynocephalus, Didelphys cynocephalus, Dasyurus cynocephalus, Peracyon cynocephalus, Didelphys cynocephala, Thylacinus harrisii, Dasyurus lucocephalus, Thylacinus striatus, Thylacinus communis, Thylacinus breviceps, Thylacinus rostralis etc.
Original range	Tasmania, previously also Australian mainland and New Guinea (Australia)
Date of extinction	1936
Causes of extinction	Hunting, loss of habitat, diseases and inbreeding

Tasmanian tiger – Unjustly persecuted?

Thylacines had the ability to open their lower jaw very widely; angles of 80 degrees or sometimes even 90 degrees have been reported. Because of this, it might be assumed that the thylacine primarily hunted large animals—indeed, it was thought so because the thylacine was notorious as a sheep killer, which ultimately led to its persecution. The Tasmanian government even paid bounties for each thylacine killed.

Researchers from the University of New South Wales in Sydney discovered in a 2011 study that the jaw of the Tasmanian tiger was too weak to eat large animals. It is now believed that the thylacine mainly fed on smaller marsupials like quolls, wallabies, and opossums.

Scientifically described first in 1808 by G. P. Harris, the (penultimate) last known thylacine died in 1936 at the Hobart Zoo. It was a female, which had been mistaken for a male throughout its life and therefore named Benjamin. In fact, Benjamin was the second-to-last thylacine, as the Tasmanian Museum and Art Gallery (TMAG) discovered in December 2022: The last known thylacine was probably an old female caught by the trapper Elias Churchill in the Florentine Valley and sold to the Hobart Zoo in mid-May 1936. Since the trapping of animals with snares was already illegal at the time, the zoo did not officially record the purchase of the animal. Only a few months after her arrival at the zoo, the thylacine died.

The National Film and Sound Archive of Australia (NFSA) rediscovered old footage from 1935 in May 2020, showing the penultimate thylacine, Benjamin, according to a statement from the film archive. This sequence had been inaccessible to the public for about 85 years. It is part of the travelogue Tasmania the Wonderland, of which only nine minutes have survived. The NFSA suspects that the early Australian filmmaker Sidney Cook was responsible for the footage.

Reasons for extinction: Hunting, disease, or inbreeding?

By the early 20th century, the thylacine was already considered rare. Tasmanian tigers held in various zoos, with one exception, never reproduced.

In addition to the theory that human hunting of the alleged sheep killer led to the extinction of this marsupial, other hypotheses exist. It has also been suggested that the thylacines died out due to a disease similar to canine distemper. A 2013 study by the University of Adelaide concludes that a distemper-like disease is unlikely to be the sole cause of extinction.

Another study published in April 2012 suggests that the thylacine population on Tasmania had limited genetic material due to inbreeding, which could have led to extinction. This is likely due to geographical reasons, as Tasmania became isolated from the Australian mainland more than 10,000 years ago.

The destruction of habitat through deforestation for pasture creation has also likely contributed significantly to the thylacine’s extinction.

Incidentally, the thylacine is not the only endemic species that has gone extinct on Tasmania. Other examples include the Cascade funnel-web spider (after 1926), the Lake Pedder earthworm (after 1972), and the Tasmanian emu (1873).

Is the thylacine alive? – Sightings not rare

Since the officially recognized extinction, there have been ongoing sightings of the Tasmanian tiger, yet conclusive proof of this species’ existence remains elusive. Numerous search expeditions have been unsuccessful, and even a one million US dollar reward offered in 2005 by the Australian magazine The Bulletin for proof of a living Tasmanian tiger yielded no results.

The internet is replete with images and videos purported to show sightings of Tasmanian tigers, such as the footage from Paul Days in June 2017, which is said to depict a running thylacine. These sightings fuel hope and curiosity, yet without verifiable evidence, the scientific community remains skeptical about the animal’s survival.

The footage in question was recorded on a farm near Moonta on the Yorke Peninsula in South Australia. While many people might see this video as proof of the existence of the Tasmanian Tiger, not everyone is convinced: Kristofer Helgen, a zoologist at the University of Adelaide, identified the animal in the video as “a fox that is likely limping or injured,” according to the Australian news site news.com.au.

Australian researchers compiled data in a study published on BioRxiv in early 2021 titled New Results: Extinction of the thylacine, noting that the thylacine was sighted a total of 1,237 times between 1910 and 2019. Of these, 429 sightings were confirmed by experts, 226 were unconfirmed, and 99 were based on physical traces of the species.

Using these figures, the scientists conducted calculations and concluded the following study results: The window for the extinction of the thylacine spans from the 1980s to the present. The data also indicate that thylacine sightings were relatively constant from 1940 to 1999 but became much rarer and less convincing after 2000.

The researchers consider it quite possible that the thylacine may have existed until the end of the 1990s. According to the study, the probability that individual thylacines still roam Tasmania and that the species is not yet extinct stands at 17 percent.

Thylacines on New Guinea?

In addition to unconfirmed sightings of the Tasmanian Tiger in Tasmania and mainland Australia after 1936, there are also recent reports of “striped dogs” in New Guinea. Particularly from West Papua, the western part of New Guinea under Indonesian administration, such reports emerge. Despite New Guinea separating from the Australian mainland about 8,000 years ago, fossil discoveries first made in 1960 confirm that Tasmanian tigers also existed there.

Already in 2013, Karl Shuker, a British zoologist and cryptozoologist, suggested that tiger hunters should shift their search from Tasmania to New Guinea. He believes that a population of thylacines might still exist on the mountainous island, one of the least explored habitats in the world.

Shuker refers to reports of animals in Papua New Guinea and the western part of New Guinea that resemble the Tasmanian tiger. These reports come from local tribes who call the creature dobsegna. It is characterized by a large mouth, a straight, long, and stiff tail, and distinctive stripes on its fur – all hallmark features of the thylacine. A mix-up with the rare New Guinea singing dog, which lacks stripes and has a flexible tail, is therefore unlikely.

Given that West Papua or Irian Jaya is one of the least explored regions in the world, the likelihood increases that the Tasmanian tiger or a similar yet undiscovered species could have survived in these inaccessible and densely forested areas. The unique ecological conditions in New Guinea might have allowed a predatory marsupial like the thylacine to survive in niches with little competition from other large predators.

To date, concrete evidence for the survival of the thylacine in New Guinea is lacking. However, recurring sightings and continued interest keep the hope alive for its possible existence. This topic is also addressed in the two-part documentary Hunt for Truth: Tasmanian Tiger (2024), where filmmaker Tim Noonan follows promising leads of the thylacine not only in Tasmania but also in Papua New Guinea.

Can thylacine be resurrected?

Since 2000, scientists from various universities in New South Wales, Melbourne, and Texas have been attempting to clone the thylacine. They have used various starting materials from the animal, such as feces, museum specimens, and alcohol-preserved fetuses or tissues.

In 2017, a team reportedly completed the sequencing of the thylacine genome, according to an article from the University of Melbourne. The genetic material used came from a juvenile that was still in its mother’s pouch at the time of death, preserved in alcohol in 1909 at the Victoria Museum in Australia.

In 2022, headlines were made by the startup Colossal, which aims to bring back the thylacine using cells from the fat-tailed dunnart (Sminthopsis crassicaudata), a native Australian marsupial. The plan involves genetically modifying dunnart cells to become artificial thylacine cells, creating a possibility for embryos that would need to be carried by a larger marsupial.

So far, a new Tasmanian tiger has not been successfully bred from the decoded genome, but this research has at least answered questions about the thylacine’s lineage. The thylacine belongs to the order Dasyuromorphia, which also includes marsupial carnivores like the quoll, Tasmanian devil, and the numbat.

There are two thylacine films: the horror film Dying Breed (2008) and the drama The Hunter (2011). In The Hunter, Willem Dafoe stars as the main character who hunts the last living thylacine in the forests of Tasmania. The drama is based on the novel of the same name by Julia Leigh.