University of Edinburgh researchers say the species discovered in Portugal was among the Earth's top predators.
The team said Tuesday it was part of a wider group of primitive amphibians that were widespread at the time.
The researchers say the "super salamanders" grew up to two meters (six feet) in length and lived in lakes and rivers. The team says the find establishes this group of amphibians lived in a more diverse geographic area than had been thought.
They are believed by paleontologists to have lived at the same time the dinosaurs began their dominance.
The new species was uncovered in a large bed of bones.
(The Associated Press)