Skull of huge sea monster Pliosaur discovered in UK's Dorset cliffs

The skull of a colossal sea monster has been discovered from the cliffs of Dorset's Jurassic Coast in the United Kingdom, reports BBC.

It belongs to a pliosaur, a fearsome marine reptile that ruled the oceans about 150 million years ago.

The two metre long fossil is one of the most complete specimens of its type ever discovered and is giving new insights into this ancient predator, according to BBC.

The skull will be featured in a special David Attenborough programme airing on BBC One on New Year's Day.

As the sheet covering the fossil was pulled back and the skull was revealed for the first time, it was immediately obvious that this pliosaur is huge and beautifully preserved.

According to local palaeontologist Steve Etches, there isn't a specimen anywhere else to match it.

"It's one of the best fossils I've ever worked on. What makes it unique is it's complete," he told BBC.

The lower jaw and upper skull are fused together just as they would have been in the creature's life. Such an incredibly detailed connection is a rarity worldwide. In most cases where specimens are found with this level of detail, crucial parts are often missing. However, in this instance, despite a slight distortion, every bone is intact and accounted for.

The skull is longer than most humans are tall, which gives a sense of how big the creature must have been overall.

The skull has 130 teeth including long and razor sharp ones at the front, which could kill with a single bite. 

The back of each tooth is marked with fine ridges. These would have helped the creature to pierce the flesh and then quickly extract its dagger-like fangs, ready for a rapid second attack.

The pliosaur was the ultimate killing machine and at 10-12 metre long, with four powerful flipper-like limbs to propel itself at high speed, it was the apex predator in the ocean.

"The animal would have been so massive that I think it would have been able to prey effectively on anything that was unfortunate enough to be in its space," said Dr Andre Rowe from Bristol University.

"I have no doubt that this was sort of like an underwater T rex."

Its meals would have comprised not only other reptiles like its long-necked relative, the plesiosaur, and the dolphin-shaped ichthyosaur, but also fossil records suggest it would have preyed upon other pliosaurs passing by.

How the fossil skull was recovered

It all began with an unexpected discovery along a beach near Kimmeridge Bay on the renowned World Heritage Jurassic Coast in southern England. 

While on a stroll, Phil Jacobs, a friend and fellow fossil enthusiast of Steve Etches, stumbled upon the tip of the pliosaur's snout resting in the shingle. Unable to carry it due to its weight, he sought Steve's help, and together they devised a makeshift stretcher to safely transport the fossil fragment.

Palaeobiologist Prof Emily Rayfield has already scrutinised the sizable circular openings situated at the back of the head. These features provide insights into the size of the muscles controlling the pliosaur's jaws and the immense forces exerted when it snapped its mouth shut, crushing its prey.

According to findings, this force amounts to approximately 33,000 newtons at the upper end. To put this in perspective, the most formidable jaws among living animals are those of saltwater crocodiles, which exert around 16,000 newtons of force.

"If you can generate a really powerful bite, you can incapacitate your prey; it's less likely to get away. A powerful bite means you're also able to crunch through tissue and bone quite effectively," the Bristol researcher explained.

"As for feeding strategies: crocodiles clamp their jaw shut around something and then twist, to maybe twist a limb off their prey. This is characteristic of animals that have expanded heads at the back, and we see this in the pliosaur."