The thylacine (Thylacinus cynocephalus), better known as the Tasmanian tiger, has long been the poster child for human-caused extinction. Hunted out of existence by Australian farmers who feared that the striped, canine-like marsupials would kill their sheep, the last thylacine died in captivity in Hobart Zoo 75 years ago next week, on September 7, 1936 (although the species was not officially declared extinct until about 25 years ago).

Now, just a few days before the annual observance of National Thylacine Day in Australia, a new study reveals that the predator was probably not a threat to sheep after all. Its notably long jaw (one of the animal's most distinctive features) could open to an amazing 120 degrees but was too weak to kill sheep, according to a study published September 1 in the Journal of Zoology.

"Our research has shown that its rather feeble jaw restricted it to catching smaller, more agile prey," lead author Marie Attard of the University of New South Wales in Australia, said in a prepared statement. Instead, it appears the thylacine killed and ate smaller animals, such as possums.

The researchers used computer models to simulate normal predator behavior—biting, tearing and pulling—and assess how that behavior would create stress against the skull of the thylacine. The models revealed that the thylacine's skull would not have been up to the task of chowing down on large animals.

But while thylacines may not have been a threat to sheep, humans still posed a threat to thylacines that could have driven the animals closer toward extinction, even without rampant, unnecessary hunting. Since the predators specialized in smaller prey, the arrival of European settlers to the Australian continent may have disturbed the landscape and forced the thylacine into closer proximity and competition with other marsupial predators, such as Tasmanian devils or spotted-tailed quolls, for prey such as bandicoots, wallabies and possums, all of which were also losing habitat to humans and agriculture.

Attard suggests that knowing that thylacines and other predators all relied upon the same food sources helps indicate why the thylacine was more vulnerable to extinction—it could not adapt to eating larger prey.

Even though it has been 75 years since the last thylacine died, many people still believe the animals exist in the remote wilds of Australia. No conclusive evidence has ever been found, although sightings are still commonly reported.

Here's footage of the last known thylacine, and its striking jaw, shot before its death in captivity:

Photo via Wikipedia