An extinct species of monstrous amphibians that lived 220 million years ago and resembling modern day salamanders was the top predator of its era.
This killer named "Metoposaurus algarvensis" was the "top predator during the time that dinosaurs were first evolving and beginning their march to dominance," said Stephen Brusatte, a paleontologist of the University of Edinburgh's School of GeoSciences, according to Live Science.
It was the size of a small car and was an ugly creature notable for its big, flat head that looked like a toilet seat with the cover down. "These amphibians would've ruled the rivers and swamps and lakes," said Brusatte.
"This new amphibian looks like something out of a bad monster movie," he noted.
"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."
Researchers also said Metoposaurus may have been sensitive to climate changes. They believe many of these creatures died at the Portuguese site when the lake they inhabited dried up.
An international team of scientists found several skulls and various other bones of Metoposaurus, including an arm, shoulder and backbone in an ancient lake bed in southern Portugal. From these bones, researchers determined the creature was a new species of metoposaurid, an extinct group of large amphibians.
Researchers noted that some 201 million years ago, a mass extinction event wiped out most big amphibians like Metoposaurus. A few survived to become part of the ancestral stock for the evolution of modern amphibians such as salamanders, frogs and newts.
"Most modern amphibians are pretty tiny and harmless," said co-author Richard Butler of the University of Birmingham. "But back in the Triassic these giant predators would have made lakes and rivers pretty scary places to be."
The study was published in the Journal of Vertebrate Paleontology.