Thylacinus cynocephalus
The Tasmanian wolf or thylacine (Thylacinus cynocephalus), also known as the marsupial wolf , Tasmanian tiger or thylacin, was a carnivorous marsupial originating in the Holocene. It was native to Australia, Tasmania, and New Guinea and is believed to have become extinct in the 20th century. It was the last living member of its genus (Thylacinus), whose other members lived in prehistoric times from the early Miocene.
The marsupial wolf became extinct on mainland Australia thousands of years before the arrival of European settlers, but it survived on the island of Tasmania along with other endemic species, such as the Tasmanian devil (Sarcophilus harrisii). Intensive hunting, encouraged by rewards, is generally blamed for its extinction, but other factors could have contributed, such as diseases, the introduction of dogs, or the occupation of its habitat by humans. Despite its classification official as extinct sightings are still reported, though none have been conclusively proven.
Like placental wolves, the marsupial wolf was a top predator. But being a marsupial, the species has no phylogenetic relationship to canids, and yet, due to evolutionary convergence, it had similar appearances and adaptations. Its genetically closest living relative is the marsupial anteater or numbat (Myrmecobius fasciatus).
Evolution
The modern marsupial wolf first appeared four million years ago. The species of the family Thylacinidae date from the beginning of the Miocene; since the early 1990s, fossils of at least seven extinct species have been recovered from Riversleigh, part of Lawn Hill National Park, north-west Queensland. Nimbacinus dicksoni is the oldest of the seven described fossil species, possessing twenty-three million years of age. This thylacinid was much smaller than its modern relatives. The largest species, Thylacinus potens, which reached the size of a wolf, was the only one to survive into the Late Miocene. In the late Pleistocene and the early Holocene, the modern marsupial wolf ranged (but was not numerous) throughout Australia and New Guinea.
As an example of convergent evolution, the marsupial wolf bore a strong resemblance to northern hemisphere canids: sharp teeth, powerful jaws, upturned heels, and the same general shape. Because the marsupial wolf occupied the same ecological niche in Australia as canids in the rest of the world, it developed many of its adaptations. Despite this, it has no close phylogenetic relationship with predators in the northern hemisphere; its closest living relative is the Tasmanian devil (Sarcophilus harrisii).
They are easy to distinguish from an authentic dog by the stripes of the back, but the skeleton is harder to distinguish. Oxford zoology students had to identify a hundred zoological specimens as part of their final examination. Soon the voice came out that, if there was never a "dog" skull, it was safe to identify it as a marsupial wolf since something as obvious as a dog skull should be a trap. One year, the examiners prepared a double trap and included a real dog skull. The easiest way to distinguish them are the two prominent holes to the palatal bone, usually characteristic holes of the marsupials.Richard Dawkins, in his book The Ancestor's Tale
Discovery and taxonomy
Australian aborigines were the first to come into contact with fur seals. Numerous examples of Aboriginal art and engravings have been found dating to at least 1000 BC. Petroglyphs of the marsupial wolf can be seen in the Dampier Rock Rock Art Area on the Burrup Peninsula in Western Australia. By the time the first explorers arrived in the late 18th century, the animal was already rare in Tasmania. In 1642, when Abel Tasman first arrived in the territory, Europeans may have had contact with him. The Tasman expedition reported the tracks of "wild beasts with paws like a tiger's". Marc-Joseph Marion du Fresne, who landed in 1772, reported the existence of a 'tiger cat'. It cannot be said with certainty that the animal observed was a marsupial wolf, as the spotted-tailed marsupial cat (Dasyurus maculatus) has a similar appearance. The first indisputable observation was made by French explorers on May 13, 1792, as explained by the French naturalist Jacques Labillardière in his journal of the expedition headed by Bruni d'Entrecasteaux. Even so, it was not until 1805 that William Paterson, Lieutenant Governor of Tasmania, submitted a detailed description, published in the Sydney Gazette and the New South Wales Advertiser.
The first detailed scientific description was made by Tasmania's Deputy Supervisor General George Harris in 1808, five years after the island's first colonization. Harris originally classified the marsupial wolf within the genus Didelphis, which Linnaeus had created by representatives of the order Didelphimorphia of American marsupials, describing it as Didelphis cynocephala. The discovery that Australian marsupials were fundamentally different from known mammalian genera led to the implementation of the current classification method, and in 1796 Geoffroy Saint-Hilaire created the genus Dasyurus, where he placed the marsupial wolf. in 1810. For concordance between the mixture of Greek and Latin nomenclatures, the name of the species was changed to D. cynocephalus . In 1824 Temminck established a new genus to house it, Thylacinus. Its common name comes directly from the genus name, originally from the Greek θύλακος (thylakos, "pocket&# 34;).
There is scientific data indicating that the thylacine belongs to a basal group in the Dasyuromorphia phylogenetic tree and that the Tasmanian devil would be the closest living species. However, an article published in January 2009 in the scientific journal Genome Research based on the mitochondrial genome of the thylacine suggests that Myrmecobius fasciatus (the numbat) is its closest relative..
Morphology
There is no total coherence between the different anatomical descriptions of the thylacine, a fact that can be explained due to the fact that the existing data is limited to the few preserved specimens, the fossil record, skin and skeletal remains, photographs, and black and white films of the animal in captivity, and chronicles of field work.
The marsupial wolf had the appearance of a large dog with short fur and a stiff tail that gradually extended from the body, similar to a kangaroo. Many European settlers drew direct comparisons to the hyena, due to its posture and general demeanor. Its yellowish-brown fur had between thirteen and twenty-one distinctive black stripes on its back, torso, and tail base, which earned it the nickname from "tiger". The stripes were more pronounced in juveniles and faded as the animal aged. One of the stripes extended down the outer part of the hind thighs. Their fur was thick and soft, up to six inches in length; in young animals the tip of the tail had a crest. Its rounded, erect ears were about three inches long and covered with short hair. Coloration ranged from yellowish-brown to dark brown; the belly was cream colored.
Adults ranged in size from 100 to 180 cm in length, including a 50-65 cm tail. The largest known specimen measured 290 cm from nose to tail. Adults were 60 cm tall. cm and weighed between twenty and thirty kilograms. There was slight sexual dimorphism, with males generally being larger than females.
The female had a four-breasted marsupium, but unlike many other marsupials, the marsupium opened toward the distal part of the body. Males had a scrotal pocket, an anatomical feature unique among Australian marsupials, into which they could tuck their scrotal sac.
A characteristic element of the thylacine was the unusual angle of maximum opening of its jaws. This ability can be seen in part in David Fleay's short black-and-white film of a captive wolf marsupial in 1933. The jaws were powerful (with profuse muscle attachment points) and contained forty-six teeth.
You can distinguish the tracks of fur seals from those of other animals, native or introduced, because unlike those of foxes, cats, dogs, wombats and Tasmanian devils, fur seals had a very large hind pad and four very obvious front pads, lying almost in a straight line. The hind feet were similar to the front feet but had four toes instead of five, the hallux being the missing toe. they were not retractable.
Early scientific research suggested that it possessed a keen sense of smell that enabled it to track prey, but analysis of its brain structure revealed that its olfactory bulbs were not well developed. It is likely that it relied on sight and hearing to hunt. Regarding the scent of the animal, some observers described a strong, characteristic scent, while others described a light, clean animal scent, and still others none at all. It is possible that the marsupial wolf, like its relative, the Tasmanian devil, released some volatile substance under stress.
Regarding locomotive aspects, some characteristic and somewhat clumsy gaits have been described, which made it incapable of running quickly. It could also perform a bipedal hop, similar to that of a kangaroo, as captive specimens have shown on a few occasions. Guiler speculates that this was a form of accelerated locomotion that the animal used when alarmed. He was also able to maintain his balance and stay in a bipedal position for short periods.
Although no recordings of the marsupial wolf's vocalizations exist, observers who have studied it in the wild and in captivity indicated that it used to growl and hiss when nervous, often completing it with a menacing yawn. When he hunted, he would emit a series of cough-like guttural barks, which he would repeat rapidly, probably to communicate with other members of the group, He would also vocalize a long, plaintive sound, probably used to identify himself from afar; and a low-pitched sound used to communicate with family members.
Ethology and behavior
Not much is known about the behavior and habitat of the direwolf. Observations have been made about its ethology in captivity, but there are only limited and anecdotal data on the behavior of the animal in the wild. Most of the observations were made during the day, when the marsupial wolf was a nocturnal animal. These observations, made during the 20th century, might have been unrepresentative because the species was already suffering from the problems that soon would lead to extinction. In fact, part of its behavior has been extrapolated from that of its closest relative, the Tasmanian devil.
It is likely that the fur seal preferred the dry eucalyptus forests, wetlands and grasslands of the Australian mainland. Australian Aboriginal petroglyphs indicate that the fur fur was widespread across mainland Australia and New Guinea; In 1990, a mummified corpse was even discovered in a cave on the Nullarbor plain, in Western Australia, which confirms its distribution in continental Australia. Radiocarbon dating revealed it to be 3,300 years old.
In Tasmania, it preferred central woodlands and coastal heaths, which eventually became a primary target for British settlers seeking suitable grazing land for their herds. The animal roamed an area that it had a maximum radius from its home of between forty and eighty kilometers. It seems that it remained within this terrain even without being territorial, on some occasions large groups of animals had been observed in the same territory, too large to be a single family.
It was a nocturnal and crepuscular hunter, staying in small caves or empty tree trunks during the day. He used to retire to the hills and woods for shelter during the day and hunted in the heather at night. Early observers noted that the animal was shy, respectful of the presence of humans, and tended to avoid contact, although at times it seemed to show more interest. According to Milligan (1853), Australian aborigines said they were swimmers. very strong.
There is evidence that the breeding season lasted year-round (sacrifice records indicate that there were young in her pouch at all times of the year), even though the main breeding season was in winter and spring. Up to four pups were born per litter (usually two or three) that remained in the pouch until they were three months old; the mother protected them until they were at least half adult size. At birth, the young were hairless and blind, but their eyes were open and their bodies were full of fur once they left the pouch. After leaving the pouch, and until they had grown large enough to help, the young animals they were left in the den while the mother hunted. Marsupial wolves bred only once in captivity, in 1899 at Melbourne Zoo. Their lifespans in the wild are estimated to be between five and seven years, but some wolves lived nine years. years in captivity.
Diet
The marsupial wolf was exclusively carnivorous. Its stomach had a thick muscular layer and could be distended to allow the intake of large amounts of food. It was probably an adaptation to compensate for long periods of unsuccessful hunting when food was scarce. Analysis of the skeletal structure and observations of the animal in captivity suggest that it selected a prey item and then pursued it until exhausted. Some studies conclude that the animal hunted in small family groups; the main group made the prey flee in the direction of a thylacine prepared to ambush them. In fact, the hunters confirmed that it hunted using the ambush technique.
Their prey included kangaroos, wallabies, wombatids, birds, and small marsupials such as kangaroo rats and phalangeriforms. Their preferred prey might have been the once abundant Tasmanian emu. This species of emu was a large flightless bird that shared the habitat of the fur seal and became extinct due to overhunting around 1850, possibly coinciding with the decline in the number of fur seals. Both dingoes and fur seals foxes also had emu as prey. During the 20th century, the marsupial wolf was often characterized as an animal that fed primarily on blood, but little reference is made to this conception today; the popularity of this description appears to have stemmed from a single indirect report. European settlers believed that marsupial wolves killed farmers' sheep and other smaller livestock. In captivity, marsupial wolves were fed a wide variety of foods, including rabbit and wallaby carcasses as well as beef, lamb, and horse meat.
Extinction
Extinction in mainland Australia
The marsupial wolf probably became extinct from the Australian mainland in the 20th century (perhaps in New Guinea). Competition with humans and dingoes is blamed for extinction. Still, there are questions about the impact of the dingoes, as the two species may not have competed directly as the dingo is primarily a daytime predator, while the direwolf is thought to have hunted mostly at night, although since they shared prey, yes they were able to compete for food. In a hypothetical direct confrontation, it should be noted that the marsupial wolf was more robust, which would have given it an advantage in combat between specimens of both species.
Cave paintings in Kakadu National Park clearly show that fur seals were hunted by early humans, and it is thought that dingoes and fur seals may have competed for the same prey, despite the different chronobiological nature of activity between the two. Their habitats clearly overlapped: subfossil remains of fur seals have been found in close proximity to remains of dingoes. The adoption of the dingo as a hunting companion by the aborigines would have increased the pressure on the marsupial wolf.
Extinction in Tasmania
Though long extinct on the Australian mainland when European settlers arrived, fur seals survived until the 1830s in Tasmania. At the time of the first European colony, the densest population area for fur seals was in the north of the island. From the earliest days of European colonization, fur seals were rare, but little by little they came to be blamed. of numerous attacks on sheep; this led to offering bounties in an attempt to control their numbers. One company, the Van Diemen's Land Company, offered bounties for killing marsupial wolves as early as 1830, and between 1888 and 1909 the Tasmanian government paid £1 a head (10 shillings for pups). In total, 2,184 bounties were paid, but it is believed that far more fur seals were killed than claimed. Their extinction is often attributed to these continued efforts by farmers and bounty hunters. Even so, multiple factors likely contributed. to its decline and eventual extinction, including competition with feral dogs (introduced by settlers), habitat erosion, extinction of prey species, and a distemper-like disease that affected many captives in those times.
Regarding competition with foxes as one of the factors involved in extinction, it should be noted that these animals were first introduced in 1864 and again in 2000; their possible presence in the wild in Tasmania is very high. seriously taken into account, even with the slightest indications of it. Of course, the Fox Free Tasmanian Taskforce, an association involved in the search for thylacines and the eradication of foxes, receives government funding and no longer makes efforts in the search of the marsupial wolf. Thus, it is suggested that the difficulty of finding foxes in the Tasmanian wilderness seems to indicate that there is some possibility that the direwolf has survived far from contact with humans.
For whatever reason, the animal was already extremely rare in the wild by the late 1920s. There were several attempts to save the species from extinction. Wilsons Promontory management committee records of 1908 recommended the reintroduction of marsupial wolves to different suitable locations in Victoria. In 1928, the Tasmanian Native Wildlife Advisory Committee recommended that all remaining fur seals be protected, in areas such as the Arthur and Pieman rivers in western Tasmania.
The last known wild dire wolf was killed in 1930 by a farmer named Wilf Batty in Mawbanna, northeast Tasmania. The animal (presumably a male) had been seen near Batty's chicken coops for a few weeks.
"Benjamin" and the search
The last captive direwolf, later known as "Benjamin" (although its sex was never confirmed), was captured in 1933 and sent to Hobart Zoo, where it lived for three years. Frank Darby, who claimed to have been a zoo worker, hinted—in a May 1968 newspaper article—that "Benjamin" had been the affective name given to the animal. Even so, there is no document that indicates that he had an affective name; and Alison Reid (the zoo's de facto police station at the time) and Michael Sharland (the zoo's publicist) denied that Frank Darby had ever worked at the zoo or that the animal had been named "Benjamin& #3. 4;. From Darby also appears to come the claim that the last direwolf was male: photographic evidence suggests it was a female. This specimen died on 7 September 1936. It is believed to have died of neglect; Isolated outside his shelter, he was exposed during a rare weather event in Tasmania of sweltering heat during the day and freezing temperatures at night.
This marsupial wolf appears in the last known film of a living specimen; 62 seconds of black and white footage showing it moving up and down its enclosure were filmed in 1933 by naturalist David Fleay. In Australia, every September 7, since 1996, the National Threatened Species is celebrated Day ('National Day of Threatened Species') to commemorate the death of the last officially recorded direwolf.
Although there was a movement in favor of the protection of marsupial wolves since 1901, motivated in part by the increasing difficulty of finding specimens for the collections of other countries, political circumstances prevented any type of official protection from being enacted before 1936. Official protection of the species by the Tasmanian Government was introduced on 10 July 1936, fifty-nine days before the last known death in captivity.
Results from subsequent searches indicate that the species may have survived in Tasmania into the 1960s. Eric Guiler and David Fleay searched for live individuals in northwestern Tasmania and found tracks and scat that might have been the animal's, heard animal voices matching the description of fur seals, and gathered anecdotal accounts from people who claimed to have seen them. However, none of these tests yielded conclusive data on its existence in the wild.
The marsupial wolf had endangered species status until 1986. International protocols require that any animal that has not been found in fifty years is considered extinct. Since no definitive evidence for the existence of the marsupial wolf has been found since the death of "Benjamin" in 1936, the species met this criteria and was declared officially extinct by the IUCN. CITES is more cautious, considering it "possibly extinct".
Unconfirmed observations
Even though it is officially extinct, many people believe that the Direwolf still exists. From time to time it is said to have been seen in Tasmania, other parts of Australia and even West Papua in Indonesia near the Papua New Guinea border. The Australian Rare Fauna Research Association has compiled some 3,800 putative sightings of the animal on the Australian mainland since its extinction date in 1936, while the Mystery Animal Research Center of Australia had recorded 138 up to 1998 and the Department of Land Conservation and Management obtained 65 in Western Australia during the same period. Independent researchers Buck and Joan Emburg of Tasmania have reported 360 sightings on the island and 269 on the mainland since 1936; figure calculated from different sources. On the mainland, observations often occur south of Victoria.
While many of the observations are immediately debunked, some have generated a lot of publicity. In 1982, a researcher from the Tasmania Parks and Wildlife Service, Hans Naarding, observed for three minutes, at night, what he considered a fur seal, at a location near the Arthur River in the northwest of the state. This news prompted a year-long government-funded search. In January 1995, a Parks and Wildlife official claimed to have observed a fur seal in the Pyengana region of northeast Tasmania in the middle of the early morning. Subsequent searches found no trace of the animal. In 1997, it was reported that some inhabitants and missionaries in the vicinity of Mount Carstensz in West Papua had seen fur seals. It appears that the inhabitants had known of them for many years but had not made an official report. In February 2005, a German tourist claimed to have taken digital photographs of a marsupial wolf near Cradle Mountain-Lake St. Clair National Park, but did not the authenticity of the photographs has been determined. The photos were only published in April 2006, fourteen months after the sighting. The photographs, which only showed the rear of the animal, were considered inconclusive as evidence for the existence of the marsupial wolf.
Possible video recordings
There are some video recordings after Benjamin's death showing animals that could be thylacines. One of the most famous shots dates from 1973. However, as the curator of the National Museum of Natural Sciences in Madrid, Josefina Barreiro, affirms, dingoes, when they are sick and very thin, can often be mistaken in the distance for a thylacine.. Another of the videos that could seem truthful was made in 2008, although it was not published until years later by the group "Thylacine Awareness Group of Australia". In it, the animal that is seen does not seem sick due to the ease with which it moves. Nothing has been confirmed or denied about this video. Subsequently, there is no news that the cameras of the scientists located in areas where the sighting of thylacines has been reported have recorded images of the animal to this day. In any case, the research on the verification of living thylacines is joined by a line of parallel economic investment for attempting their genetic reconstruction by means of cloning.
Rewards
In 1983, Ted Turner offered a $100,000 reward for proof of the existence of the direwolf. Even so, in a letter sent in 2000 in response to a request from a direwolf hunter in Murray McAllister, indicated that the bounty had been withdrawn. In March 2005, the Australian news magazine The Bulletin, published weekly in Sydney, offered a reward of $1.25 million for the safe capture of a live marsupial wolf, as part of its one hundred and twenty-fifth anniversary celebrations. When the offer expired at the end of June 2005, no one had produced evidence of the animal's existence. Tasmanian tour operator Stewart Malcolm has offered a $1.75 million reward. Still, taking is illegal under current law, as the species is protected; therefore, any reward for their capture is invalid as a capture license was not issued.
Current projects and research
As far as current research is concerned, there are two parallel lines: the search for living specimens, on the one hand, and, on the other, the attempt at their genetic reconstruction, a project that is not without controversy.
International database
Records of all specimens, many of which are part of European collections, are currently in the International Thylacine Specimen Database (ITSD). The ITSD was completed in April 2005 as the result of a four-year search project aimed at cataloging and digitally photographing, if possible, all known surviving fur seals from all museums, universities and private collections.. The master records are physically located at the Zoological Society of London.
Record of evidence
Since Benjamin's death, some 5,000 suspected clues have been reported, including footprints, scat, sightings and blurry photographs, in part shown to be from feral dogs or dingoes. However, in 2017 there were two sightings that could correspond to thylacines on the Cape York Peninsula (not in Tasmania, but in the far northeast of Australia). In a statement from James Cook University, it was stated that based on the information provided, the sightings could be plausible, so it was decided to start a systematic search in the area with the installation of fifty automatically activated cameras. It is not the first time that an action of this type has been carried out, although there is still no news of positive results.
Cloning project
The Australian Museum in Sydney began a cloning project in 1999. The aim was to use genetic material from preserved specimens from the early 20th century to clone new individuals and resurrect the species. Some geneticists have accused this project of being a gallery action, and its main supporter, Professor Michael Archer (Dean of Science at the University of New South Wales, former director of the Australian Museum and evolutionary biologist), received a 2000 nomination for the Australian Skeptics Bent Spoon Award, for "perpetrating one of the most absurd examples of paranormal or pseudoscientific bullshit".
In late 2002, researchers had some success when they were able to extract replicable DNA from the preserved specimens. On February 15, 2005, the museum announced it was halting the project after analysis showed that DNA recovered from the specimens it was too degraded to be usable. In May 2005, Professor Michael Archer announced that the project was reopened by a group of interested universities and a research institution.
Genome Sequencing
At the end of 2017, a team led by the University of Melbourne sequenced the thylacine genome, making its genetic map one of the most complete for a species considered extinct. This discovery reveals that it was a genetically vulnerable animal. According to Andrew Pask, an adjunct professor at the university, "Knowing that the Tasmanian tiger faced limited genetic diversity before its extinction means that, if it had survived, it would have had to fight for its life in a similar way to the Tasmanian devil", that is, they would have faced the same ecological difficulties as that species, with a weak immune system.
Cultural references
The marsupial wolf is a de facto symbol of Tasmania. It appears on the Tasmanian coat of arms, the official logos of Tasmanian Tourism and Launceston City Council. Since 1998 it has featured prominently on Tasmanian car license plates. It has been a continuous reason for representations embodied in numerous collector's items and souvenirs, including key rings, brooches and patches. It has also been included in poster art along with the Tasmanian devil.
The story of the marsupial wolf was the subject of a campaign by The Wilderness Society entitled We used to hunt Thylacines. One of the covers of Australian Geographic magazine has been illustrated and dedicated to the marsupial wolf. National Geographic responded to correspondence regarding subsidizing search efforts for his find.
It appears on products at Hobart's Cascade Brewery and in their television commercials. In video games, Ty the Tasmanian Tiger is the star of his own trilogy. In the early 1990s cartoon show Tazmania, the character Wendell T. Wolf was supposedly the last surviving direwolf. Tiger Talo is a children's book based on an aboriginal myth about how the marsupial wolf got its stripes. He is the mascot of the Tasmanian Tigers cricket team and has appeared on stamps in Australia, Equatorial Guinea and Micronesia.
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