Scientists recently discovered remains of an ancient four-legged whale found in 42.6-million-year-old marine sediments along the coast of Peru. According to the study which has appeared in the journal Current Biology, provided a new insight into whales’ evolution and their dispersal to other parts of the world.
Olivier Lambert of the Royal Belgian Institute of Natural Sciences told Daily News Egypt that he and his team have discovered a new quadrupedal whale skeleton from the middle Eocene period (nearly 43 million years ago) at the deposits of the Pisco Basin, southern coast of Peru.
He noted that this is the first indisputable four-limbed whale record for the whole pacific and southern hemisphere, probably the oldest for the Americas, and the most complete skeleton of such a whale outside India and Pakistan. This new record demonstrates that cetaceans reached a nearly circum-tropical distribution early in their evolutionary history, and that they reached the New World while retaining the ability to move on land (i.e. being amphibious).
The geological age of the new whale, its place of discovery, and its affinities with more fragmentarily known quadrupedal whale remains from the west coast of Africa also support the hypothesis that amphibious whales crossed the South Atlantic to reach South America, before a northward dispersal along the east coast of the US, according to Lambert.
Responding to our inquiry about how did the team know exactly the features of the old whale, Lambert explained that some features of the discovered remains are directly based on the observation of the skeleton, for example the tight connection between the hip and sacrum, limb proportions, and the presence of small hooves on toes and fingers.
“Other features rely on comparisons with other semi-aquatic mammals, for example the feet and hands being webbed and the significant use of the tail for swimming. Finally, others are much more hypothetical, for example the presence of a tail fluke, as the last tail vertebrae were not recovered,” he said.
