March 12, 2014

Desperate Bid To Protect The Fragile Tasmanian Tiger In The Museum - Updated: Another Meat-eating Marsupial Found?


                                                               

   
I wonder if we will ever know if there are any left.
It certainly doesn't look promising. 

At least there is much work going on to save the Tasmanian Devil - also an endangered mammal, and also native to Tasmania and closely related to the tiger. Much of this work is being done by Devil Ark.
        More about the Tasmanian Devil here.

It looks exactly like what it is - a creature long dead - but the animal lying on its side at the National Museum of Australia in Canberra is facing a new kind of threat.

Conservators, wearing masks, gloves and laboratory coats for protection against the chemicals they are using, have just pulled the crudely skinned thylacine carcass from a display case filled with liquid the colour of strong tea.

Among them is Simon Moore, a British freelance conservator who is an expert in the conservation of natural science specimens.

The museum has asked him to assess the thylacine, or Tasmanian tiger, which has become so fragile it has been removed from public display. Even vibrations created by people walking by the plate-glass container were damaging it.


''We've been concerned about the condition of the thylacine, which is very important for us and for the nation,'' deputy manager of conservation Nicki Smith said. ''We want to make sure we're doing the best that we can for it.''
Ms Smith said the Tasmanian tiger was first removed from display in 2002, when the preserving solution became so cloudy it was difficult to see the animal. The solution was changed and the specimen returned to public display in 2005, but the liquid again turned cloudy and the thylacine was removed.

Tests suggested protein from muscle, or calcium carbonate from teeth and bones, were leaching into the solution, thus weakening the specimen's structural strength.

Mr Moore, whose career includes 23 years at the Natural History Museum in London, said while the overall condition of the specimen appeared stable, he had found some white and waxy tissue near the pelvis.

''I can't say yet what it was, but it could be slightly fatty,'' he said. ''But it shouldn't be like that because formalin and preservatives stabilise fats.''

The sound generated by tapping the thylacine's bones and teeth suggested they were solid and had not decomposed, despite the carcass having being preserved some time between 1928 and 1930.

Liquid samples from the internal cavity signalled all was well with the internal organs. ''That's very encouraging, because sometimes a specimen can look fine from the outside but it can be deteriorating from the inside,'' Mr Moore said.

The thylacine is one of more than 2400 items in the museum's so-called wet collection that Mr Moore reviewed on Monday.

Among them is Phar Lap's heart, weighing 6.35 kilograms. ''At the museum in London [there] was an elephant heart, and it was almost as big as that.''

With thanks to the Sydney Morning Herald

                                                                     


From You Tube:


A review of over 350 reports from the Australian state of Tasmania that claim a vicious predator, once thought to have been hunted to extinction, has made a comeback—the Tasmanian Tiger, and how an Australian biologist is using preserved DNA of the animal in hopes of cloning a living specimen.

The thylacine (/ˈθaɪləsaɪn/ THY-lə-syn,[3] or /ˈθaɪləsiːn/ THY-lə-seen, also /ˈθaɪləsɨn/; binomial name: Thylacinus cynocephalus, Greek for "dog-headed pouched one") was the largest known carnivorous marsupial of modern times. It is commonly known as the Tasmanian tiger (because of its striped back) or the Tasmanian wolf. Native to continental Australia, Tasmania and New Guinea, it is thought to have become extinct in the 20th century. It was the last extant member of its family, Thylacinidae; specimens of other members of the family have been found in the fossil record dating back to the early Miocene.

The thylacine had become extremely rare or extinct on the Australian mainland before European settlement of the continent, but it survived 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. Despite its official classification as extinct, sightings are still reported, though none have been conclusively proven.

Like the tigers and wolves of the Northern Hemisphere, from which it obtained two of its common names, the thylacine was an apex predator. As a marsupial, it was not closely related to these placental mammals, but because of convergent evolution it displayed the same general form and adaptations.

Its closest living relative is thought to be either the Tasmanian Devil or numbat.
(ED: Actually I think the numbat is an entirely different creature)

The thylacine was one of only two marsupials to have a pouch in both sexes (the other being the water opossum). The male thylacine had a pouch that acted as a protective sheath, covering the male's external reproductive organs while he ran through thick brush. It has been described as a formidable predator because of its ability to survive and hunt prey in extremely sparsely populated areas.



Update: another meat-eating marsupial?


According to new research led by Marie Attard of the University of New England in collaboration with colleagues from the University of New South Wales, Australia, the reconstruction of an extinct meat-eating marsupial’s skull, Nimbacinus dicksoni, suggests that it may have had the ability to hunt vertebrate prey larger than itself.

The complete research results appeared April 9 in the open access journal PLOS ONE in an article titled, “Virtual Reconstruction and Prey Size Preference in the Mid Cenozoic Thylacinid, Nimbacinus dicksoni (Thylacinidae, Marsupialia).”

According to the Parks & Wildlife Service of Tasmania, the Thylacine, also known as the Tasmanian tiger, was shy and secretive and always avoided contact with humans.  Despite its common name, “tiger,” it had a quiet, nervous temperament compared to its small cousin, the Tasmanian devil.  Captured animals generally gave up without a struggle, and many died suddenly, apparently from shock.

Nimbacinus dicksoni is a part of an extinct family of Australian and New Guinean marsupial carnivores, Thylacinidae.  Excluding one recently extinct species, the bulk of information known about species in this family comes from recovered skull fragments, which of course restricts species ecology and diversity analysis.  Scientists recovered a preserved skull of Nimbacinus dicksoni dating between 16 and 11.6 million years old from the Riversleigh World Heritage Fossil Site in northwestern Queensland, Australia. 

The researchers used the skull to determine if Nimbacinus dicksoni was more likely to hunt small or large prey.

The researchers applied virtual 3D reconstruction techniques and computer modeling to recreate the skull of Nimbacinus, digitally “crash-testing” and comparing it to models of large living marsupial carnivores – including the Tasmanian devil, spotted-tailed quoll and northern quoll – and to the recently extinct Tasmanian tiger, a close relative of Nimbacinus dicksoni.

The researchers found that the resemblance in mechanical performance of the skull between Nimbacinus dicksoni and the spotted-tailed quoll, was greater than the similarity to the Tasmanian tiger. 

 Furthermore, the authors suggest that Nimbacinus dicksoni, a medium-sized marsupial , had a high bite force for its size, was primarily carnivorous, and was likely proficient in hunting vertebrate prey that exceeded its own body mass.

With thanks to the Science Recorder