After being lost in storage for 50 years, the remains of a 170-million-year-old Jurassic-era dinosaur nicknamed the Storr Lochs Monster have finally been uncovered by scientists in Scotland.

At 4 metres (13 feet) long, the 'sea monster' is an aquatic reptile with a pointed mouth, and belonged to the ichthyosaur family of large marine reptiles. The species likely died out just before the dinosaurs did.

"For half a century the museum kept the fossil safe and secure, but there wasn't the expertise to free it from the very dense rock that surrounded it, or the expertise to study it," one of the team, Steve Brusatte from the University of Edinburgh, told the AFP.

"But now we finally have that expertise … and have realised that this skeleton is the most complete fossil of a sea reptile ever found in Scotland."

The newly rediscovered remains were originally unearthed back in 1966 by amateur fossil hunter Norrie Gillies on Scotland's Isle of Skye. According to Michael Greshko at National Geographic, they represent the most complete Jurassic-era marine reptile fossil ever recovered in the country.

But since the discovery of the fossil, little had been done with it. In fact, up until his death in 2011, Gillies reportedly contacted the museum several times to see what was being done with it, but to no avail.

Not that the museum was ignoring Gillies - given that the specimen was trapped under layers of rock and represented one of the most complete skeletons of its kind ever found, the curators were being extra careful not to damage or destroy the remains by moving them or examining them too much.

For fear of destroying the remains, the museum kept them in safe-keeping, and they were all but forgotten until 2015, when Brusatte and his team rediscovered the fossil and even reconnected with Gillies' family.

Over the course of the next year, the team painstakingly chipped away at the rock to reveal the monster inside.

"Dad's not around to see it himself, but I know he'd be very, very pleased to know that it's finally being displayed, and he'd also be very pleased to know that it's the company he worked for that helped to make it happen," Norrie Gillies' son, Allan, who was only a child when the fossil was discovered, told National Geographic.

The project was also funded by SSE, the energy company that Nessie Gillies worked at when he found the fossil.

The team hopes that the fossil will help them to better understand why the creature went extinct, and why so many large, sea reptiles died out during the mid-Jurassic.

"In the oceans [of the Middle Jurassic], it looks like there was a big turnover between smaller, more primitive reptiles and larger, more derived groups. It looks like that, though, because we don't have that many fossils from that time period anywhere in the world," Brusatte said.

"That's what makes this potentially an internationally important specimen. It's one of the few good fossils of an ichthyosaur that comes from this 'dark' period."

Brusatte also hopes the fossil will invigorate people's interest in the Jurassic era - a time when real monsters did actually roam the oceans (sorry, Loch Ness Monster fans).

"People don't realise that REAL sea monsters used to exist," he told the AFP. "They were bigger, scarier, and more fascinating than the myth of Nessie. The new fossil is one of them. It actually lived in Scotland 170 million years ago!"

The team's work has yet to be published in a peer-reviewed journal, though based on the rarity of the fossil, publication will likely be forthcoming once their analysis is complete. 

The remains are now on display at the National Museums Scotland.