This is what the pliosaur might have looked like.
The skull of a giant sea monster which lived in the oceans 150 million years ago has been discovered.
The terrifying animal, called a pliosaur, is thought to have been up to 16m long and could have weighed a whopping 12 tonnes.
Pliosaurs lived around the same time as the dinosaurs. They had huge heads like a crocodile, powerful jaws and a set of razor-sharp teeth.
The fossil was found on the south coast of England.
Part of the pliosaur's skull
Pliosaur expert Richard Forrest said: "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."
He reckons that its jaws would have been so strong it could have bitten a small car in half!
Scientists are going to study the skull and reckon it'll give them lots of new information about the animals and what life was like back then.
There are also plans for it to go on display in a local museum.