Paleontologists at the University of California, Davis and the Smithsonian Institution’s National Museum of Natural History estimate that: Colossus of PercetusA gigantic basilosaur whale that lived in the Eocene of Peru and was 17 meters long and weighed between 60 and 70 tons.

Colossus of Percetus They lived in what is now Peru about 39 million years ago (Eocene epoch).

This species was first described in 2023. Basilosauridaean extinct cetacean family that lived in the Eocene and is known on all continents, including Antarctica.

“Colossus of Percetus“The bones are unusually dense,” said Ryosuke Motani, a professor at the University of California, Davis, and Dr. Nicholas Pienson of the Smithsonian Institution.

“Mammal bones are usually solid on the outside and spongy or hollow in the center. In some animals, much of the center is filled with solid bone, which makes it denser and heavier. There are some that are.”

“In aquatic animals, heavy bones offset the buoyancy of body fat and fat, allowing them to maintain neutral buoyancy underwater or, in the case of hippos, to walk on riverbeds.”

“Fossil whale bones have an extensively filled interior and an overgrowth of bone on the outside. A condition called pachyostosis is also found in some modern aquatic mammals, such as manatees. .”

In 2023, paleontologists estimated the weight of the following people: Colossus of Percetus 180 metric tons (range from 85 to 340 metric tons).

This results in Colossus of Percetus Despite being much shorter at 17 meters (17 meters) compared to the 30 meters (30 meters) of the blue whale, it weighs as much or more than the largest known blue whale.

“These estimates indicate that Colossus of Percetus It's incredibly dense,” Professor Motani said.

“It would have been a whale's job to stay on the surface and get out of the ocean. To do anything underwater, it would have had to keep swimming against gravity.”

The authors reviewed the assumptions used to make these estimates.

“The first problem is that the original study used fossil bones to estimate skeletal weight, and assumed that skeletal and non-skeletal mass increases at the same rate as body size increases, which increases the total animal weight. “It's an extrapolation,” they said.

“But measurements in other animals show that this is not the case.”

“Initial estimates also overestimated how much overall weight would increase as a result of hypertrophy.”

“However, the evidence for manatees shows that their bodies are relatively light compared to their skeletal mass.”

Professor Motani and Dr Pienson estimate the total length to be 17 meters. Colossus of Percetus It weighs between 60 and 70 tons, much lighter than any known blue whale.

individuals of Colossus of Percetus A whale that grows to 20 meters can weigh more than 110 tons, but that's still a long way off the 270 tons of the largest blue whale.

“Thanks to the new weight, the whale, like most whales, is able to rise to the surface and remain there while breathing and recovering from the dive,” Professor Motani said.

of result Published in an online magazine Peer J.

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R. Motani and N.D. Pienson. 2024. Downsizing in the heavy class: Factors and methods for revising mass estimates of giant fossil whales. Colossus of Percetus. Peer J 12: e16978; doi: 10.7717/peerj.16978