INTERNATIONAL: Paleontologists have unearthed the skull of a ferocious marine predator, an ancient ancestor of modern-day whales, which once lived in a prehistoric ocean that covered part of what is now Peru, scientists announced on Thursday,March 17.

The roughly 36-million-year-old well-preserved skull was dug up intact last year from the bone-dry rocks of Peru's southern Ocucaje desert, with rows of long, pointy teeth, Rodolfo Salas, chief of paleontology at Peru's National University of San Marcos has announced.

Scientists think the ancient mammal was a basilosaurus, part of the aquatic cetacean family, whose contemporary descendents include whales, dolphins and porpoises.

Basilosaurus means "king lizard," although the animal was not a reptile, though its long body might have moved like a giant snake.

The one-time top predator likely measured some 39 feet long, or about the height of a four-story building.

"This discovery is very important because the skull is in a perfect state of preservation.," said Salas, adding the skull, which has already been put on display at the university's museum, may belong to a new species of basilosaurus.

"These animals were the largest predators at the time.," added Salas.

Scientists believe the first cetaceans have evolved from mammals that lived on land some 55 million years ago, about 10 million years after an asteroid struck just off what is now Mexico's Yucatan peninsula, wiping out most life on Earth, including the dinosaurs.

Salas has explained that when the ancient basilosaurus died, its skull likely sunk to the bottom of the sea floor, where it was quickly buried and preserved.