A groundbreaking discovery: the most complete pliosaur skull ever found

An enormous skull, found on the coasts of the United Kingdom in 2022, has entered the Guinness Book of Records: the fearsome fossilized marine reptile is in fact intact for around 95% of the surface, and is therefore the most complete pliosaur skull ever discovered

On the coast of the United Kingdom, a monumental discovery has been made that sets a new world record. A fossilized skull of a formidable marine reptile, affectionately named ‘Sea-Rex,’ has been identified as the most complete pliosaur skull ever found, with an astonishing 95% of its surface intact.

Pliosaurs, ancient and extinct reptiles, some of which measured more than 10 meters from nose to tail, were among the most formidable predators to roam the Earth’s oceans. They boasted the most powerful bite ever seen in a marine reptile, estimated to be between 33,000 and 48,000 Newtons (N), two to three times greater than that of the saltwater crocodile (Crocodylus porosus), the heaviest modern reptile and surpassing all other living animals with a crushing force of up to 16,414 N. In comparison, humans typically have a maximum bite force of only about 700 N.

This prehistoric reptile’s skull, measuring just aapproximately 6.56 feet in length and 1.97 feet in width, lived more than 150 million years ago. It was discovered in April 2022 along the Dorset coast in Southern England by amateur fossil hunter Phil Jacobs. However, it’s only now that its incredible condition has been confirmed.

While skulls of this species of similar size are not uncommon, and it is believed this specimen was still young and not fully grown at its time of death, it’s the condition in which it was discovered that has earned it a spot in the Guinness World Records. The skull includes almost all of its original bones along with 130 razor-sharp teeth and was found lying in a vertical position, essentially in its original three-dimensional shape, with jaws still intertwined as in life.

The remains are so exceptional that they could greatly aid archaeologists in understanding not only the biology of these somewhat enigmatic animals but also their behavior and “lifestyle.” For instance, the upper jaw is dotted with what appear to be sensory pits (similar to those seen in crocodiles today) that likely helped to detect prey movement.

“I have studied many Kimmeridgian pliosaurs (belonging to the Late Jurassic, Ed.) – commented Judyth Sassoon to the Guinness World Records (GWR), a researcher at the University of Bristol (UK) – but I have never seen one as well preserved as [this]. It contains many anatomical details in a single specimen that are only partially preserved in others.”

In general, if a specimen contains clearly visible anatomical features, it can aid research in two ways: first, the details can provide phylogenetic information, helping to understand pliosaurs as an evolving group; additionally, they can aid in understanding how the animal grew, leading to a better comprehension of its lifestyle.

“For example, by preserving the details of its sensory apparatus, the skull can provide information on hunting and feeding habits that not only tell us about the individual but can be generalized to other similar pliosaurs.”

As of January 2nd, the skull is on display at the Etches Collection Museum of Jurassic Marine Life.

Sources: Guinness World Records / Etches Collection Museum of Jurassic Marine Life/Youtube / BBC/Youtube