A powerful tail, four legs, membranes between the fingers and hooves. This is the whale rebuilt by a team of paleontologists from a well preserved fossil found in Peru. The question is why four legs? The results, published in Current Biology, lead us to think that the body of this marine mammal, four meters long, adapted to its survival on land and sea. He lived 42.6 million years ago and could swim and also walk on his four limbs.
The jaws were flush with the desert floor and, when digging, the researchers found the lower jaw, teeth, vertebrae, ribs, parts of the front and back legs with long fingers that were probably flattened. A part of the tail vertebrae has similarities to those of current semi-aquatic mammals, such as otters. For Olivier Lambert, of the Royal Belgian Institute of Natural of Sciences and leader of the team that has analyzed the bones, this finding will provide information on the evolution of the whales and their conquest of the oceans to expand across the planet. The fossil was found in 2011 during excavations of marine sediments on the Pacific coast of Peru, at a site called Media Luna Beach.“This is the most complete specimen ever found of a four-legged whale outside India and Pakistan,” says Lambert.
Its location surprised the researchers, since it is believed that the first whales evolved for the first time in South Asia about 50 million years ago. As their bodies adapted to the water, they migrated to North Africa and North America, where other fossils have been found. This latest discovery suggests that the first whales managed to swim there from South America.
Whales are considered an icon in the evolution of species. They went from small mammals with hooves to being the blue whale we know today. This new specimen has been called Peregocetus pacificus, which means the traveling whale that arrived in the Pacific.