A toothy, dolphin-like predator which prowled the oceans in the Jurassic era, when dinosaurs roamed the Earth, has been uncovered in a Scottish museum where it lay buried for 50 years, scientists said Monday.

First discovered in 1966, the fossil has at last been freed from its prehistoric sarcophagus to reveal a chunky, four-metre-long (13 feet) deep-sea killer -- its pointed mouth bristling with hundreds of cone-shaped teeth.

"It is spectacular," said palaeontologist Steve Brusatte of the University of Edinburgh's School of Geosciences, who helped expose the 170 million-year-old remains.

Dubbed the Storr Lochs Monster, the reptile belonged to the ichthyosaur family -- scary-looking, finned hunters sometimes called sea dragons -- that died out shortly before the dinosaurs, to be replaced by dolphins and whales.

Encased in rock, this set of remains was found by an amateur on a beach on the Isle of Skye 50 years ago, and presented to the National Museum of Scotland.

"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," Brusatte told 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.

- 'Scarier than Nessie' -

The fossil monster will go on display at the museum as the "crown jewel" of Scottish prehistory, the scientist added.

Earlier this year, researchers said prehistoric global warming had wiped out the ichthyosaurs after an impressive 157-million-year deep-sea reign.

There had been several sub-species.

For Brusatte, these creatures are much more impressive than their fictional Scottish counterpart, the Loch Ness Monster, could ever hope to be.

"People don't realise that REAL sea monsters used to exist," he said by email.

"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 find of such a complete ichthyosaur fossil should help shed more light on the animals' reign and sudden demise.