T. rex “a Kitten” Compared to Dorset Sea Monster say Experts as New Exhibit Opens

By |2024-04-18T07:09:37+01:00October 27th, 2009|Dinosaur and Prehistoric Animal News Stories, Dinosaur Fans, Main Page|1 Comment

Giant Pliosaur Remains Go On Display in Dorset (England)

The fossilised jaws of one of the largest predators known to science are going on in display in Dorset, the remains of the 2.4 metre long jaws of a gigantic marine predator, a pliosaur, are providing scientists with clues about just how dangerous swimming would have been in the mid Mesozoic.

According to palaeontologist and plesiosaur expert Richard Forrest, Tyrannosaurus rex was a “kitten” compared to this ferocious short-necked plesiosaur.  Although, it is difficult to estimate the size of the entire animal based on partial jaws and elements of the skull this creature, whose fossils were found in Upper Jurassic coastal strata on the aptly named Jurassic coast (Kimmeridigian faunal stage), scientists speculate that this huge carnivore could have exceeded over 50 feet in length.  The fossils were found by a local collector, who was lucky enough to discover them after elements of the fossil had eroded out of the unstable cliffs.  The collector kept returning to the same spot to see what tide and time was revealing of the monster.  The fossils found to date have been purchased by Dorset County Council, who hope to display this beast at the local county museum.

The Huge Lower Jaws of the pliosaur

Picture credit: Dorset County Council

The picture shows the huge lower jaw bones of the as yet not fully scientifically described pliosaur, the tip of the jaws is facing the camera.  The animal that possessed these powerful jaws would have been able to swallow an adult human in one bite.

Commenting on the fossilised bones, that went on display for the press, palaeontologist Richard stated:

“I had heard rumours that something big was turning up.  But seeing this thing in the flesh, so to speak, is just jaw dropping.  It is simply enormous.”

Related to the long-necked plesiosaurs, pliosaurs became the top marine predators from the Early Jurassic into the Cretaceous.  They were characterised by their short, powerful necks, massive skulls and huge jaws filled with large, pointed teeth.  An animal such as the Dorset find would have been the top predator in the ecosystem.  This may help explain why so many ichthyosaur bones have been found that indicate an attack or feeding from a huge predator.  Indeed, one fossilised skeleton of an ichthyosaur indicates that it may have been bitten in half.  A pliosaur with 2.4 metre long jaws such as this leviathan would have been capable of such a feat.  Pliosaurs and plesiosaurs evolved an unusual method of swimming, one that is not known in nature today.  These animals used their huge four flippers to power their way through the water.  Each flipper would have twisted as it beat up and down, creating a backward thrust that drove these large animals forward.  The motion is a little like flying underwater, it is thought that most of the propulsion came from the rear flippers but even the front flippers may have exceeded 3 metres in length and been immensely strong.

Dr David Martill, a palaeontologist from the University of Portsmouth described pliosaurs stating:

“These creatures were monsters!  They had massive, big 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 are suggesting that this latest discovery could turn out to represent one of the largest pliosaurs ever found.  Although a full study has yet to be carried out and scientists are confident that more fossils of this specimen will be found soon, early estimates put this animal at around 10-16 metres in length and weighing between 7 and 12 tonnes.  These estimates are not the exaggerated estimates so typical of a big pliosaur discovery.  The 25 metre length of Liopleurodon is open very much to question, but there is no doubting this was a big beast, capable of eating everything else in the Jurassic seas around 150 million years ago.

The scale drawing above compares a frogman with a Killer Whale (Orca) and the new pliosaur.  Although the drawing shows the pliosaur at the top end of the estimated size for this beast, even at 10 metres long it would have been much bigger and heavier than a Killer Whale.  This new discovery could rival other recent finds as being the largest carnivore known from the fossil record.  A pliosaur named “Predator X” found in Svalbard, is estimated to be around 16 metres long.  A slightly earlier find “The Monster of Aramberri” discovered in 2002 in Mexico is believed to be of a similar size to the Dorset find.

A Pliosaur Replica on Display at a Museum


A replica of a pliosaur on display at a museum. Picture credit: Everything Dinosaur.

Picture credit: Everything Dinosaur

The specimen has yet to be properly prepared in a laboratory, but early indications are that it has been remarkably well preserved and more of the specimen might be buried in the cliff and eroded out.

Plesiosaur expert Richard Forrest, commented that the skull was in very good condition, most skull material associated with pliosaurs has been compacted or even crushed flat, so little anatomical data can be assembled.  However, this specimen is in almost 3-D so the great power and strength of the jaws can be appreciated.

He said:

“Pliosaur skulls are very big, but not that robust, in general, and you tend to find them crushed flat – completely ‘pancaked’.  What is fantastic about this new skull, not only is it absolutely enormous, but it is pretty much in 3-D and not much distorted.”

He went on to add:

“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.”

It is certainly true, just as top sea predators today are much bigger than apex land predators, the same would have occur ed in the Mesozoic.  The advantage of having water to help support their weight would have given pliosaurs the opportunity to grow bigger and heavier than even the largest carnivorous dinosaurs.

Dorset County Council has purchased the fossil remains for £20,000, Heritage Lottery Funds were used to secure this unique specimen.

Discussing the purchase, David Tucker, the County’s museums advisor said:

“Our aim is to purchase fossils found along the Jurassic Coast World Heritage Site and to get them into local museums – we want to put really exceptional fossils in museums.”

These huge predators certainly capture the public’s imagination, animals like Liopleurodon are very popular with dinosaur fans and our taste for super predators seems unlikely to be diminished, indeed our fascination for these huge marine reptiles seems to grow with every new exciting discovery.

To view a model of Liopleurodon, pliosaurs and other marine prehistoric animals, visit the models section of the Everything Dinosaur website: Dinosaur, Marine Reptile and Prehistoric Animal Models.