Chances are this freakish creature has shown up somewhere in your feed this week.

While it looks like a cross between a giant salamander and a boomerang, you might be surprised to find out that what you're looking at is in fact a real animal – except it went extinct some 270 million years ago. 

The photograph, which has been shared widely on various media platforms over the years, isn't of a living creature; Instead, it shows a beautiful model of Diplocaulus, created by Japanese sculptor Goro Futura. 

These large amphibians roamed the earth from the Carboniferous Period (360 million years ago) into the late Permian, spending their days cruising shallow waters and likely dining on insects and fish. That bizarre head might look completely alien, but it's a shape we still see in nature today. Just look at the mata mata turtle (Chelus fimbriatus):

Image: Pierre Pouliquin/Flickr

Having a wide head could have helped Diplocaulus in a number of ways. For starters, you can see how swallowing one would have been problematic. It's also possible that the surface acted as a hydrofoil – much like the kind seen on modern boats – allowing the amphibians to swim against a current. 

Funnily enough, this isn't the first time a Diplocaulus model has caused a bit of a stir. Back in 2007, a model jokingly called "DIAD" (Diplocaulus in a dish) was also confused for a real creature. The story was squashed shortly afterwards, but the model even made the pages of British zoologist and cryptozoologist Dr Karl P. N. Shuker's book, Extraordinary Animals Revisited.

Image: University of Michigan/Wikimedia Commons

A quick Google will reveal several YouTube videos claiming to show living Diplocaulus specimens, but Shuker, who has long been fascinated by ancient amphibians, has spent many moons debunking "sightings" like these.  

"All of them have been filmed and uploaded by the same person," he writes. "Either he or she is unaccountably successful at locating living specimens of an amphibian deemed extinct for at least 250 million years by palaeontologists, or, all is not as it seems."

Diplocaulus on display at the University of Michigan's Natural History Museum. Image: University of Michigan/Wikimedia Commons

He adds that being extinct hasn't stopped Diplocaulus from throwing a few curveballs our way. Small trace fossils have been found showing a pair of flaps linking the tips of the head with the rest of the body, suggesting that the animal may not have been as hammer-headed as we thought.

"It might well instead have resembled the restoration on display at the University of Michigan's Natural History Museum," he says.  "Diplocaulus is still defunct, but it remains one of my favourite prehistoric creatures – even if it has lost its boomerang!"

Top header image: Dmitry Bogdanov/Wikimedia Commons