A mysterious six-foot-long animal skull, which could belong to a 150-million-year-old sea monster, was recently recovered under British cliffs.

“This is a once-in-a-lifetime find,” Steve Etches, British paleontologist, stated. “It is one of the best fossils I’ve ever worked on and I doubt I’ll ever work on anything like it again.”

Etches is determined to find the rest of the sea creature after the recent discovery. The creature is speculated to be a marine reptile called the pliosaur and the skull was extracted from Dorset’s Jurassic Coast.

“The rest of the body is without doubt still in that cliff,” Etches stated. “It will take a lot of collaboration and funding, but I’d love to get it out – the cliffs are eroding by a few feet every year and I think it’s important to science that we save the whole thing.”

The discovery of the tip of the pliosaur’s snout was made by Philip Jacobs, a textile designer who has hunted for marine reptile fossils on the Jurassic coast for decades. After he realized what he had found, Jacobs reached out to Etches and the two used a makeshift stretcher to transport the skull.

“It was very exciting but, thinking logistically, not a good place to collect a fossil from,” Etches recalled, per The Guardian. “The cliffs are sheer, crumbling and unsafe, eroding quickly. It’s a very dangerous area – with large rockfalls and slippery ledges – so safety was paramount.”

The preserved skull is equipped with 130 teeth and, according to Etches, they estimate that the creature measured 30 to 39 feet with four fins, enabling it to swim fast and attack its prey.

“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 of the University of Bristol, per BBC News. “I do not doubt that this was sort of like an underwater T. rex.”

Speculated to likely be a new species, the discovery of the skull will be the subject of an upcoming documentary presented by Sir David Attenborough, Attenborough and the Giant Sea Monster. The documentary aired on BBC One on January 1st and will air on PBS on February 14th. The pliosaur’s skull will also be on display at the Etches Collection museum in the village of Kimmeridge in Dorset next year.

“Research-wise it will bring people from all over the world, and I can’t wait for local children and school groups to see it too. For years to come this fossil will be a source of new information and people will come to study it – including Dr Judyth Sassoon who is writing the scientific paper. Together we’ll come to a consensus on what a pliosaur was and how it operated in the Jurassic seas. This will reveal a tremendous amount of new information that we previously didn’t know about pliosaurs.” Etches stated.