The New Giant

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Blue whales are currently the heaviest animals on Earth but about 39 million years ago it was outclassed by another marine heavyweight, the Independent reported.

Scientists recently studied the skeletal remains of a previously unknown species discovered 13 years ago in the Ica desert in southern Peru.

Aptly named Perucetus colossus, the extinct titan had a body mass between 93 and 375 tons and measured from 56 to 66 feet in length. When compared to the blue whale, P. colossus was shorter but it was two to three times heavier than the modern cetacean.

In their study, the research team estimated the body mass of P. colossus by applying the soft tissue to skeleton mass ratio from present-day marine mammals. The substantial bone mass in the gigantic animal is attributed to two skeletal modifications: The external addition of bone to skeletal parts and the internal cavity filling with dense bone material.

They classified the P. colossus as a basilosaurid, a family of extinct cetaceans – a class that includes dolphins, whales and porpoises.

Living around 41 million to 23 million years ago, it was a slow swimmer and lived near the coast, according to researchers.

The authors say that the P. colossus’ immense size reveals some new details about the evolutionary history of mammals at a time when some land-based animals were returning to the ocean.

The shift toward gigantism in marine mammals is traditionally thought to have started around five to 10 million years ago, but the new discovery suggests that this trend might have originated about 30 million years ago.

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