A fossil of a whale with legs from 42.6 million years ago
Cetaceans are a group that includes whales and dolphins. Researchers believe that the order of these mammalsóin originated from today’s terrainóIn southern Asia. Its roots go back more than 50 millionóin years back from a small, even-toed predator thatóry powrócialized to live in the oceans.
In the pages of „Current Biology” A description of an ancient, four-legged whale has been published, whichórego remains were found along the coast of Peru in marine sediments of 42.6 millionów years. The findings have given researchers a better understanding of how whales evolvedów and their spread around the world.
It seems that the animal, to whichóhe remains belonged to, was adapted bothóto live in the water, as well as on land. The shape of the nóg and growths, whichóre likely to be the remains of hooves suggesting that it was able to support its body weight on land. This is also indicated by the morphology of the pelvis. Other anatomical features, including a powerful tail and otter-like finned feet, suggest that it was róalso an excellent swimmer. Someóre features of the vertebraeóThe tail legs resemble those found in beaversów and otters, suggesting significant tail involvement during swimming.
In 2011, an international teamół from Peru, France, Italy, the Netherlands and Belgium have discovered in a coastal desert in southern Peru the remains of a whale thatórego inóat the time were named Peregocetus pacificus, Which means „migrating whale, whichóry reached the Pacific”. – Digging wokół the bones we discovered, we quickly realized that it was a legged whale skeleton – with both fore and hind limbs – said Olivier Lambert of KróThe left Belgian Institute of Natural Sciences, head of theówny study author.
Older, but smaller ancestral fossils had already been discovered in theóin the whaleów with four limbs. The specimen from Peru has a more complete skeleton and fills a key gap in knowledge about the evolution of these creatures and their spread throughout the world’s oceans.
– Other examples include more fragmentary, less complete specimens of the – admitted Lambert. – So far, we have had no clear indicationóon their ability to swim and walk – added.
The specimen from Peru is four meters long including the tail. Its sharp teeth and long snout suggest that early whales may have eaten fish or crustaceans. These animals may have spent several days or weeks in the water while retaining the ability to roam on land. Researchers believe they moved on land with more grace than seals do today.
The location of the latest discovery has róThe importance of. Earlier, much older ancestors were discovered in India and Pakistanóin the whaleów. Dating has indicated that they lived about 53 million years ago. Until now, it was unclear when and how the whales dispersed throughout the Americas.
The geological age of the find and its presence on the west coast of South America strongly supports the hypothesis that cetaceans reached the New World quite early via the South Atlantic. Researchers suggest that the whales were helped by the podróve surface currents and the fact that at that time the distance between the two continents was half what it is today. According to scientistsów, only after reaching South America did the cetaceans migrate to póNorth, eventually reaching the Americas PóNorth.
According to Lambert, it is likely that whales initially returned to land to mate and give birth to offspring. The first fully aquatic whales date to about 41 to 35 millionów years ago.