Fossil-enthusiast Philip Jacobs found the fossil during a walk along England's Jurassic Coast in mid-2022.

Scientists have now begun scaling the brittle, eroding cliff faces in the area in order to uncover the skeleton remains of the creature's body.

"I'd stake my life on the rest of the animal being there, that's for sure," said Steve Etchers, owner of The Etches Collection Museum of Jurassic Marine Life, in Kimmeridge, England.

"Really, it should come out because it's in a very rapidly eroding environment. This part of the cliff is going back by feet a year," he told the BBC in December 2023.

Described as the "ultimate marine predator", the pliosaur was a class of dinosaur that appear much like a enormous crocodile, measuring up to 12 metres.

Its gigantic 2-metre long skull hosted 130 razor sharp teeth, and held the equivalent biting power of a t-rex. Paleontologists consider the pliosaur was once the apex predator of the ocean.

"What make this [skull fossil] unique is it's complete. So the lower jaws and the upper skull are meshed together, as it would be in life," Mr Etchers said.

"To find that, I think worldwide, there's hardly any specimens like that and if there are, there are bits missing.

"It's one of the best fossils I've ever worked on, I'll never probably work on another [like it]."