In Poland, the remains of a terrible prehistoric “sea monster” that could reach 30 feet in length have been found.

Archaeologists dug up bones from the enormous Jurassic sea predator in a cornfield, dating the creature back to 150million years ago.

These terrifying creatures had massive fearsome jaws that could tear through the bodies of large animalsCredit: Science In Poland

Researchers uncovered 150million-year-old remains of the ‘sea monster’ in a Polish cornfieldCredit: Science In Poland

The bones belong to a creature called a pliosaur, which would have terrorised the seas in ancient times.

They were crocodile-like, with large heads and huge toothed jaws that would swim and hunt for fish, turtles and even large crocodiles.

The creature would roam the seas of Europe and South America.

At the time – in the late Jurassic period – Poland’s southern region was an archipelago of tropical islands.

The area at the time would’ve been a tropical archipelago of islands surrounded by warm waterCredit: Science In Poland

It would have had warm lagoons and shallow sea reservoirs, according to Science in Poland.

“They measured over 10 metres in length and could weigh up to several dozen tons,” said palaeontologist Dr Daniel Tyborowski, of the Polish Academy of Sciences, speaking to the website.

“They had powerful, large skulls and massive jaws with large, sharp teeth. Their limbs were in the form of fins.

“We found bones of these pliosaurs in the north of the Świętokrzyskie Mountains.”

Palaeontologists uncovered the predator’s remains in the village of Krzyżanowice.

They found the creature alongside several other animal species from the same era.

This included plesiosaurs, a long-necked cousin of the pliosaur, as well as turtles and the distant ancestors of modern-day crocodiles.

Researchers say that this accumulation of Jurassic fossils is unique in the world.

The Jurassic predators hunted underwater, eating almost anything they could catch and killCredit: Bournemouth News

Pliosaurs could measure up to 30-40 feet in lengthCredit: Alamy

“This environment was home to the marine reptiles we discovered,” said Dr Daniel.

“Sea turtles ate large snails, while they themselves fell prey to large crocodiles.

“We know this because we found teeth marks left by those reptiles on turtle shells.

“On the other hand, powerful pliosaurs hunted all animals whose fossils we discovered at this site.”

Researchers will continue investigating the site in the hope of finding even bigger or more complete creatures.

“We hope that the next months and years will bring ever richer material in the form of bones of large reptiles.”