Scientists name large ancient marine reptile 'Tylosaurus rex'

You've probably heard of the Tyrannosaurus rex - one of the largest theropod dinosaurs that ever existed.

But, it wasn't the only T. rex that ruled during the Cretaceous Period.

Scientists have discovered a large ancient marine reptile, that has been named 'Tylosaurus rex.'

Experts say the predator had strong muscles and saw-like teeth, and lived around 80 million years ago.

The discovery was made by a team of scientists including those from the American Museum of Natural History, Perot Museum of Nature and Science and Southern Methodist University in America.

Researchers looked at previously discovered fossils that had already been found in places across the country, including the US states of Texas and Kansas.

After carefully examining the bones and teeth, scientists realised that the creature was actually a different species from other known marine reptiles called tylosaurs.

The giant sea reptile was given the name Tylosaurus rex, which means "king of the tylosaurs."

Experts say it had a streamlined body, long snout with large teeth, four paddle-like flippers and a powerful tail.

The creature lived in a huge inland sea that once split North America into two parts during the time of the dinosaurs.

The reptile could grow up to 13 metres long, which is even bigger than some Tyrannosaurus rex dinosaurs.

Co-author of the study, Ron Tykoski, said Tylosaurus rex would have been twice the length of today's largest great white sharks.

Experts believe it was one of the top predators in the sea at the time.

Palaeontologist Amelia Zietlow, who led the study, explained: "Strong muscles and serrated teeth suggest that Tylosaurus rex was preying on other large animals, likely other marine reptiles and large fish, and ripping them to pieces.

"Tylosaurus species in general were not picky eaters - their teeth are not super specialized towards any one kind of prey," she added.