Scientists discovered an ancient "giant salamander" that may have been the most ferocious predator in Portugal during its reign.

The amphibian, dubbed Metoposaurus algarvensis , existed about 200 million years ago, at the same time as the dawn of the dinosaurs, the University of Edinburgh reported. It was almost six feet long and lived in lakes and rivers during the Late Triassic Period.

"This new amphibian looks like something out of a bad monster movie. It was as long as a small car and had hundreds of sharp teeth in its big flat head, which kind of looks like a toilet seat when the jaws snap shut. It was the type of fierce predator that the very first dinosaurs had to put up with if they strayed too close to the water, long before the glory days of T. rex and Brachiosaurus," said study leader Steve Brusatte, of the University of Edinburgh's School of GeoSciences.

The discovery of the fossils suggests the group of amphibians related to salamanders was more geographically diverse than previously believed. Fossils of species belonging to this group have been discovered in regions of modern day Africa, Europe, India and North America. Differences in the skull and jaw structure of the bones discovered in Portugal suggest they belonged to a different species.

It is believed that the majority of this amphibian group was wiped out during the mass extinction 201 million years ago, long before the extinction event that wiped out the dinosaurs. During this time the supercontinent of Pangaea also started to break apart into separate continents.

"Most modern amphibians are pretty tiny and harmless. But back in the Triassic these giant predators would have made lakes and rivers pretty scary places to be," said Richard Butler, of the School of Geography, Earth and Environmental Sciences at the University of Birmingham.

The findings were published in a recent edition of the Journal of Vertebrate Paleontology.