A skull of a Sea-Rex pliosaur was found off the coast of England.

A 6.6-foot-long pliosaur skull with its upper and lower jaws still locked together in their original configuration has been discovered by British scientists. Palaeontologists have an exceptionally good picture of how one of the most formidable predators in the Jurassic Ocean actually bit and fed because of this unique preservation.

The skull was discovered unharmed.

The skull, which was preserved in its original geometry by being encased in granite along the Jurassic Coast of England, came out with its bones intact attached. Dr. Steve Etches recognised the specimen's remarkable completeness and safeguarded it, documenting the full structure as it was hauled off the cliff.

In contrast to the majority of marine reptile skulls that break or disperse prior to fossilisation, this one only slightly distorted the close fit between the upper skull and lower jaw.

Instead of using a rebuilt assumption, this structural integrity now enables researchers to study the animal's bite and feeding mechanics from an undisturbed framework.

An unprecedented fossil

According to Guinness World Records, the skull's total surface area is around 95% intact. The jaws, which were somewhat less than six feet six inches (two meters) long and roughly two feet wide (0.6 meters), contained about 130 teeth.

The display was covered by local media, and the first public display of the skull was reported in a Meridian article. According to Dr. Etches, "this is the most complete Pliosaur skull that has been discovered to date."

Logistics of a Cliff Rescue

Philip Jacobs, an amateur fossil hunter, discovered the snout tip on the shore beneath Kimmeridge Bay on April 5, 2022. Following that clue, a crew went back in August 2022 and down the cliff from ropes approximately 49 feet (15 meters) below the surface.

The bones were shielded by cutting the rock into blocks, and cautious lifting prevented the skull from breaking while being transported. Fossils along the World Heritage Jurassic Coast are continually being exposed by erosion, yet they can be quickly erased by the same waves.

Evaluating the biting force

Researchers use the scars left by the former attachment of the jaw muscles to guide their reconstruction of the bite. A 2014 study tested a gigantic marine reptilian skull using biomechanics, the study of forces in bodies.

Computer models can retain the teeth in place and prevent additional assumptions when the jaw hinges remain aligned. Because fossil skulls cannot maintain the missing muscle and cartilage, bite-strength measurements remain questionable even with pristine bones.

Giving the animal a name

Although scientists have colloquially dubbed the skull "Sea-Rex," they cannot agree on whether it is part of a known species or something completely different. To make a decision, they look for characteristics that remain constant by comparing tooth sockets and skull proportions with those of older fossils.

The standards for identifying and classifying species are based on a lengthy sorting process called taxonomy, which offers minimal opportunity for error. Arguments concerning Sea-Rex will remain tentative and subject to change until researchers release a definitive description.

The fundamentals of top predators

Other reptiles frequently fell into the jaws of pliosaurs, which sat close to the top of food webs in Jurassic waters. The animal's swimming was propelled forward by four flippers, each of which pushed water backward.

They lived only at sea, unlike dinosaurs, and most likely preyed on fish, squid, and other marine reptiles. Because Sea-Rex's entire skull allows scientists to verify these hunting theories against actual bone rather than conjecture or artwork, it is significant.

Clay and conservation

The Kimmeridge Clay Formation, a fossil-rich clay rock that was deposited in warm Jurassic seas, is where Sea-Rex originated. The clay may dry and shrink once collectors expose it to air, and the squeeze may cause bone cracking.

Because hurrying could break delicate bones behind the mouth, Etches cleaned the area for ten months, removing rock one grain at a time. Even when they are initially well preserved, the majority of marine reptile skulls fall apart due to these hidden stresses.

TV and museum audiences

The skull was put on display by the museum on January 2, 2024, transforming a lab bench triumph into a public showcase. Following the excavation and restoration, the David Attenborough documentary, which aired on January 1, 2024, used visuals to describe the animal.

The sealed joints of the skull were easier for many people to understand than a drawer full of strewn fossils. Researchers must distinguish between what the bones reveal and what television adds since public attention also builds expectations.

Beyond the skull hints

It appears that the head broke away prior to burial because a few vertebrae—the bones that make up the spine—came up with the skull. Heavy portions of the corpse sank first as the currents pushed it, and where oxygen levels remained low, muck soon buried it.

Scavengers were hindered by this quick burial, which also kept joints taut so that minerals could repair tissue. The cliff might include fragments of the skeleton, but finding the remainder could help explain how the animal perished.

Consequences for fossils

A beach find was transformed into a unique test case for the functioning of a Jurassic predator by one intact skull. Even with careful investigation, scientists may still be limited in their ability to confirm its identity and feeding mechanism.