Sea monsters really did exist - and the frightening proof that they terrorised the oceans near East Devon 155 million years ago now sits in a museum.

The giant fossilised jaws of a huge marine reptile, the same length as a train carriage on the Exmouth to Exeter Train Line, was unveiled by the doyen of natural history, Sir David Attenborough at the Dorset County Museum last week.

Dating back around 155 million years, the skull of a pliosaur – or ‘greater lizard’ - was discovered on the nearby Jurassic Coast World Heritage Site, and is one of the largest and best preserved fossils of its kind ever found.

And the find throws up an intriguing possibility –just how many other terrifying finds are ready to be discovered from beneath the red-rocks of the Jurassic Coast, under the feet of Exmouth, Budleigh, Sidmouth and Seaton’s residents and holidaymakers?

Belonging to a creature up to 18m in length - the skull is a staggering 2.4 m long and is believed to have possessed the biggest bite of all time – it was powerful enough to break a small car in half and roamed the oceans of the world when just a single continent, Pangaea, existed.

Legendary natural history film-maker Sir David unveiled the monster at the museum in Dorchester, before it went on display last week.

The fossil bones were recovered by amateur collector Kevan Sheehan between 2003 and 2008 as they were washed out of a landslide on the coast in Weymouth Bay.

The largest piece weighed over 80 kilos. Kevan missed only four pieces, three of which were recovered by two other collectors. In total, the skull is 95 per cent complete.