After all, a whale A 30-million-year-old fossil found in Peru may not be the heaviest animal ever, according to a new analysis by experts at UC Davis and the Smithsonian Institution.
New test sites A colossal porcupine again in the same weight range as u Whales modern and smaller than the largest blue whales ever recorded. The work is published on February 29 in PeerJ.
Fossil skeleton Perucetus was discovered in Peru and described in an article in Nature in 2023. The animal lived about 39 million years ago and belonged to an extinct group Whales primitive species called basilosaurids.
Erroneous estimates of the weight of Perucet
Bones from Perucetus They are unusually thick. Mammalian bones usually have a solid outer surface and are spongy or hollow in the middle. Some animals have more of their center filled with solid bone, making them dense and heavy. In aquatic animals, heavy bones can counteract the buoyancy of body fat and fat, allowing the animal to maintain neutral buoyancy in water or, in the case of the hippopotamus, to walk on riverbeds.
Fossil bones whale They have extensive padding and extra bony growth on the outside, a condition called pachyostosis, which is also seen in some modern aquatic mammals such as manatees.
Based on a number of assumptions, the original authors (Giovanni Bianucci of the University of Pisa, Italy and colleagues) estimated body mass at Perucetus 180 metric tons (between 85 and 340 metric tons). That would mean Perucetus was as heavy or heavier than that blue whales the largest known, although considerably shorter, 17 meters long, compared to sa blue whale about 30 meters.
Professor Ryosuke Motani, a paleobiologist in the Department of Earth and Planetary Sciences at UC Davis, said these estimates would Perucetus It was incredibly thick.
“It would be a job for you whale stay afloat or even leave the seabed; “It would require constant swimming against gravity to do anything in the water,” Motani said in a statement.
Motani and Nick Pyenson of the Smithsonian Institute’s National Museum of Natural History reviewed the assumptions used to generate these estimates.
The first problem is that Bianucci and his team used fossil bones to estimate skeletal mass and then extrapolated it to the mass of the whole animal, assuming that skeletal and non-skeletal mass would increase at the same rate as body size. . But measurements from other animals show that’s not the case, Motani and Pyenson say.
Perucetus weighed between 60 and 70 tons
Original estimates also overestimated how much total body mass would increase as a result of pachyostosis. But evidence from manatees shows that their bodies are relatively light in proportion to their skeletal mass.
Motani and Pyenson estimate that Perucetus17 meters long, weighed between 60 and 70 tonnes, considerably less than the known weight blue whales. AND Perucetus which grew to 20 meters, may have weighed more than 110 tons, still well below 270 tons blue whales larger.
“The new weight makes it possible whale surface and stay there while breathing and recovering from the dive, as most WhalesMotani said.
Paleontologists have not yet discovered a skull or teeth Perucetus, so it’s hard to know what he ate. You need a lot of food to maintain a huge body. Bianucci and others have suggested that Perucetus it may have eaten coastal fish and crustaceans or scavenged dead bodies, as some sharks do. New reduced site size estimate Perucetus on a scale similar to that of the sperm whale (80 tons, 20 meters long), which hunts large prey such as squid. (With information from Europa Press)
