Lima. The excavation of skeletal parts and the search for the skull of the heaviest animal in the history of the earth begins in Peru. In 2023, an international research team led by the Stuttgart paleontologist Dr. Eli Amson in the inhospitable and difficult to access Ica Desert of Peru Parts of the skeleton of a gigantic sea creature. The find attracted worldwide attention.
It is a marine mammal, a primitive species of whale from the Basilosaur family. So far, 18 fossilized bones of this ancient, long-extinct whale, which is said to have weighed around 200 tons, have been found. Since they were excavated in the Peruvian desert, the animal was given the name Perucetus colossus. Dating of the sediments surrounding the bones suggests that the animal lived about 39 million years ago.
“The fossils were discovered 13 years ago, but due to their size and shape, it took three years before they could be brought to the Peruvian capital Lima, where they have been studied ever since,” explains Eli Amson from the discovery team led by paleontologist Mario Urbina.
It turned out that the bones are extremely dense. “Each vertebra weighs more than 100 kilograms, that’s unimaginable,” says Rebecca Bennion from the Royal Belgian Institute of Natural Sciences in Brussels.
“It took several men to get them to the middle of the museum floor so I could do a 3D scan. The team drilled into the center of some vertebrae to determine the bone density. But the bone was so dense that the drill broke on the first try.”
The team believes that the extreme bone density is not a disease characteristic, but rather an environmental adaptation that enabled the large whale to swim well and forage for food even in shallow water. Similar bone features can also be found in modern manatees, for example.
Perucetus is said to have been 17 to 20 meters long, which is not unusual. However, his bone mass was probably between 5.3 and 7.6 tons. If you add organs, muscles and fat, the animal could have weighed between 85 and 320 tons, depending on estimates.
“The amazing thing about Perucetus is not its size, but the fact that it was that big more than 30 million years ago, while scientists assumed that gigantism in whales only occurred 4.5 million years ago.”
Now a team of paleontologists from the University of Pisa have returned to the archaeological site in Peru to unearth the complete skeleton of this impressive marine mammal.
The excavation work in recent years has been severely hampered by the hostile conditions on site, meaning that it was not possible to continue using conventional methods. For this reason, the use of a mechanical excavator was chosen for the latest expedition, an extreme but necessary measure to remove several cubic meters of rock.
