Scientists say fossils of a partial skeleton discovered in Peru were of an ancient species of whale that is estimated to have weighed more than 300 tons. They say it could be the heaviest animal ever to exist on Earth.

An international team of scientists published its findings in Nature magazine on Wednesday.

The researchers found fossils of the creature, including vertebrae and ribs, in southern Peru.

They modeled the ancient whale from the partial skeleton, which is estimated to be about 39 million years old.

The scientists estimate it was about 20 meters long and had a body mass between 85 and 340 tons.

The body mass equals or exceeds that of the blue whale, which has been believed to be the heaviest known animal.

The researchers believe the animal lived in shallow waters. They say the fossil record of whales is very important to document the evolutionary history of mammalian life.