Palaeontologists 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.
The roughly 36-million-year-old well-preserved skull, with rows of long, pointy teeth, was dug up intact last year from the bone-dry rocks of Peru's southern Ocucaje Desert.
Scientists think the ancient mammal was a Basilosaurus, part of the aquatic cetacean family, whose contemporary descendants include whales, dolphins and porpoises.
Basilosaurus means "king lizard" and although the animal was not a reptile, its long body might have moved like a giant snake.
The one-time top predator likely measured some 12 metres long, or about the height of a four-storey building.
"It was a marine monster," Rodolfo Salas, chief of palaeontology at Peru's National University of San Marcos, told reporters.
Dr Salas said the skull may belong to a new species of Basilosaurus.
Scientists believe the first cetaceans 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 Yucatán Peninsula, wiping out most life on Earth, including the dinosaurs.
Dr Salas 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.
"Back during this age, the conditions for fossilisation were very good in Ocucaje," he said.
ABC/wires
