Scientists have found fossils* in a coastal desert of southern Peru of a four-legged whale that lived both in the sea and on land about 43 million years ago.
The 4m mammal, named Peregocetus pacificus, represents an important stage before whales became fully adapted to living in water, the scientists said.
Its four limbs were able to hold its weight on land, meaning Peregocetus could return to the rocky coast to rest and perhaps give birth while spending much of its time at sea.
Its feet and hands had small hooves and were probably webbed to help with swimming. With long fingers and toes, and relatively slender limbs, moving around on land may not have been easy.
Its tail and webbed feet, however, indicate that Peregocetus could swim well, too, much in the same way modern-day otters do. So Lambert and his colleagues categorized the creature as amphibious (meaning it lived partially in water and partially on land).
But that doesn’t mean the animal was good at walking, and “certainly not at running,” according to the Los Angeles Times. It likely ate in the water and only took to solid ground for activities like breeding and giving birth, Lambert told the LA Times.
This finding would make less likely another hypothesis according to which whales reached North America via Greenland.
The Pisco Basin, off Peru’s southern coast, likely holds numerous fossils, given its excellent conditions for preservation.