The fossilised skull of a "sea monster", which may be the largest of its type ever found, has been unearthed on the Dorset coast.
The skull from the ferocious prehistoric predator the pliosaur is 2.4 metres long and could belong to a creature measuring up to 16 metres in length from tip to tail and weighing up to 12 tonnes.
Pliosaurs were a form of plesiosaur, a group of giant aquatic reptiles that terrorised the ocean 150m years ago, around the same time that dinosaurs roamed the Earth.
They had short necks and huge, crocodile-like heads that contained immensely powerful jaws and a set of huge, razor-sharp teeth.
Richard Forrest, a plesiosaur expert, said the discovery was fortunate because pliosaur skulls were generally found crushed flat.
"What is fantastic about this new skull, not only is it absolutely enormous, but it is pretty much in 3D and not much distorted," he said. "You have this wonderful lower jaw – and you can just see from the depth and the thickness that this was immensely strong.
"It could have taken a human in one gulp; in fact, something like a T-Rex would have been breakfast for a beast like this."
The fossil was found by a local collector on the Jurassic Coast, a 95 mile stretch of coastline covering Dorset and East Devon that spans 185m years of geological history. Dorset county council purchased it for £20,000 with money from the heritage lottery fund, and it will now be scientifically analysed, prepared and then put on public display at Dorset County Museum.
Using four paddle-like limbs to propel its bulky body through the water, the pliosaur made easy work of passing prey such as dolphin-like ichthyosaurs and even other plesiosaurs.
"These creatures were monsters," said David Martill, a palaeontologist from the University of Portsmouth.
"They had massive muscles on their necks, and you would have imagined that they would bite into the animal and get a good grip, and then with these massive neck muscles they probably would have thrashed the animals around and torn chunks off.
"It would have been a bit of a blood bath."
Experts believe it could rival recent finds made in Svalbard, an archipelago in the Arctic Ocean, where beasts dubbed "the Monster" and "Predator X" were thought to have measured 15m, and in Mexico, where the "Monster of Aramberri" was discovered in 2002, and is believed to have been of similar dimensions.
"We only have the head, so you cannot be absolutely precise," said Martill.
"But it may be vying with the ones found in Svalbard and Mexico for the title of the world's largest."
The exact location of the find is not being revealed, as Dorset county council does not want to encourage people to head to the spot. The area is unstable and prone to rock falls and landslides.
Richard Edmonds, the council's earth science manager for the Jurassic Coast, said the rest of the creature may still be entombed in the rock but it could take decades for it to emerge.
"The ground is dipping very steeply, and as it is such a huge specimen it will be buried beneath layer upon layer of rock, so we will have to patiently wait for the next big landslide," he said.