Skeletal remains of quadrupedal whale found in middle Eocene deposits in Peru

"This is the most complete skeleton of a quadrupedal (non-pelagicete) cetacean outside Indo-Pakistan," Lead Contact Olivier Lambert pointed out.

According to Current Biology, cetaceans originated in South Asia more than 50 million years ago from a small quadrupedal artiodactyl ancestor.

The scientific journal states that the finding supports early dispersal of cetaceans to the New World across the South Atlantic.

"Amphibious whales gradually dispersed westward along North Africa and arrived in North America before 41.2 mya. However, fossil evidence on when, through which pathway, and under which locomotion abilities these early whales reached the New World is fragmentary and contentious," reads the report.

On the other hand, the discovery is the first record of an amphibious whale for the whole Pacific Ocean.

"Peregocetus pacificus gen. et sp. nov. is a new protocetid cetacean discovered in middle Eocene (42.6 mya) marine deposits of coastal Peru, which constitutes the first indisputable quadrupedal whale record from the Pacific Ocean and the Southern Hemisphere," Current Biology explained.

"Preserving the mandibles and most of the postcranial skeleton, this unique four-limbed whale bore caudal vertebrae with bifurcated and anteroposteriorly expanded transverse processes, like those of beavers and otters, suggesting a significant contribution of the tail during swimming," it added.

Additionally, this quadrupedal whale combines terrestrial locomotion abilities and use of the tail for swimming.

"This new record from the southeastern Pacific demonstrates that early quadrupedal whales crossed the South Atlantic and nearly attained a circum-equatorial distribution with a combination of terrestrial and aquatic locomotion abilities less than 10 million years after their origin and probably before a northward dispersal toward higher North American latitudes," the publication explains.

(END) NDP/RMB/MVB