Seen any extinct species lately? Maybe a thylacine or two? 

A new new video doing the rounds online claims to provide evidence of a living thylacine, a species that's supposed to be extinct. But before you get too excited, this sighting (like so many others) is no doubt a case of mistaken identity and wishful thinking, experts say.

Thylacines also go by the names "Tasmanian tiger" and "Tasmanian wolf", though they were neither tigers nor wolves, but marsupials. They even had backward-facing pouches for holding their tiny developing babies! The resemblance to a wolf is not purely coincidence, though. While they weren't closely related, the similar body shapes of these two carnivores evolved along with similar hunting lifestyles. (This is a good example of convergent evolution, see also: the similar body shapes of dolphins and sharks.)

Sadly, thylacines are not with us any longer. Most went extinct in mainland Australia around 2,000 years ago, and while a surviving population held on in Tasmania, they didn't last long once European settlers showed up. With fragmented habitats and bounties on their heads (of which over 2,000 were redeemed), thylacines quickly diminished. The last known survivor died in Hobart Zoo in 1936. That same year, the animals were placed on the protected wildlife list, but none has been seen since. Fifty years later, the species was officially declared extinct.  

And that's where the video comes in. It was actually taken back in 2008 in southern Australia, but was released on Friday by the Thylacine Awareness Group of Australia, who have made it their mission to prove that these animals are still around. The group's founder, Neil Waters, says the recorded animal's stripes, strange walk and long, thin tail help identify it as a thylacine, and not a dog or a fox.

The footage does show a dog-like animal with a thin tail and a very strange limping gait. But like so many videos of mysterious animal sightings, this one is grainy, taken from at least 200 metres away, and it's hard to make out any details, including stripes.

"What got me was the head, like a prehistoric-looking head on it," says the woman who filmed the sighting. She also claims she saw this animal and others on a dozen separate occasions, and that all of them were striped. She's quite certain the creatures were thylacines.

But experts aren’t convinced. Dr Darren Naish, a palaeontologist and author of several books on cryptozoology, is highly skeptical.

Naish points out in another tweet that the head of the animal is the wrong shape, and the back legs are too long for a thylacine. As for the thin tail, he adds, it's what you would expect to see on a mangy fox that's missing its usually bushy fur. Dr Ross Barnett, an evolutionary biologist who also studies extinct animals, tweeted this video of a fox with mange for comparison. Still others have pointed out that the video was taken not in Tasmania, but on mainland Australia, where all reliable evidence indicates these animals went extinct millennia ago.

Post-extinction sightings of thylacines are not unusual. According to the Tasmania Parks and Wildlife Service, hundreds of thylacine sightings have been reported over the past century, and several search parties have gone out looking for clues, but no one has been able to provide conclusive proof. So far, all we have are grainy videos and hearsay. "We need solid DNA evidence like hair or a scat or sadly a roadkill carcass until [scientists will] even think about it," Waters admitted after releasing another video earlier this month.

Despite the lack of conclusive evidence and the skepticism of scientists, Waters and many others remain determined to find living thylacines. Unlike with other cryptids such as Bigfoot or Loch Ness, there is a certain poignancy to the search for the thylacine. It's hard not to think that if we could discover a living population of these fascinating marsupials, it could assuage some of the collective guilt we feel for eradicating them, and give us a second chance to save them. It's a nice thought, however unlikely it may be. 

And if you've never watched this iconic footage of the last known living thylacine, here's your chance to see what these creatures really looked like: