At a Glance
- The fossilized remains were found in 42.6 million-year-old marine sediments at Peru's Playa Media Luna.
- Researchers say the four-legged whales were equally adept on land and in the water.
- The whale discovered in 2011 was about 13 feet long and moved like an otter in water.
The fossilized remains of an ancient four-legged whale with otter-like features have been discovered in marine sediments along the coast of Peru.
According to scientists, cetaceans, the group of mammals that include dolphins and whales, evolved from a small, four-legged hoofed ancestor that roamed the Earth during the Eocene period, which lasted from 56 to 33.9 million years ago.
In 2011, the fossilized remains of one of these four-legged amphibious creatures was found in 42.6-million-year-old marine sediments at Peru's Playa Media Luna. The discovery has helped shed some light on the evolution of cetaceans, an international team of researchers said in a report published Thursday in Current Biology.
"This is the first indisputable record of a quadrupedal whale skeleton for the whole Pacific Ocean, probably the oldest for the Americas, and the most complete outside India and Pakistan," Olivier Lambert of the Royal Belgian Institute of Natural Sciences said in a press release.
The whale that has since been given the name Peregocetus pacificus, which means "the traveling whale that reached the Pacific," had small hooves on the tips of its appendages. The hooves coupled with the morphology of the creature's hips and limbs suggest the whale was able to walk on land.
On the other hand, the "anatomical features of the tail and feet, including long, likely webbed appendages, similar to an otter, indicate that it was a good swimmer, too," the researchers note.
The whale was about 13 feet long, including its tail, and was capable of maneuvering its large body both on land and in the water. Movement in the water would have been similar to otters, the researchers say.
Scientists believe the the four-legged whales originated in South Asia and as their bodies adapted to water, they migrated first to the western coast of Africa before traveling westward towards South America via surface currents. After reaching South America, it is believed the whales then migrated northward towards North America, where other fossils have been found.
"Whales are this iconic example of evolution," Travis Park, an ancient whale researcher at the Natural History Museum in London, told the BBC. "They went from small hoofed mammals to the blue whale we have today. It's so interesting to see how they conquered the oceans."
