NEW YORK (AP) – There may be a new contender for the heaviest animal that ever lived. While today’s blue whale has long held the title, scientists have unearthed fossils of an ancient giant that could tip the scale.
Scientists described the species – called Perucetus colossus or “the colossal whale from Peru” – in the journal Nature on Wednesday. Each vertebra weighs over 220 pounds (100 kg), and its ribs measure nearly 5 feet (1.4 meters) long.
“It’s just exciting to see such a huge animal that’s so different from anything we know,” said Hans Thewissen, a paleontologist at Northeast Ohio Medical University who had no role in the research.
The bones were discovered more than ten years ago by Mario Urbina of the University of San Marcos’ Natural History Museum in Lima. An international team spent years digging them out from the side of a steep, rocky slope in the Ica desert, a region of Peru that was once underwater and is known for its rich marine fossils. The results: 13 vertebrae from the whale’s spine, four ribs and a hip bone.
The massive fossils, which are 39 million years old, “are unlike anything I’ve ever seen,” said study author Alberto Collareta, a paleontologist at Italy’s University of Pisa.
After the excavations, the researchers used 3D scanners to study the surface of the bones and drilled into them to look inside. They used the huge — but incomplete — skeleton to estimate the whale’s size and weight, using modern marine mammals for comparison, said study author Eli Amson, a paleontologist at the State Museum of Natural History in Stuttgart, Germany.
They calculated that the ancient giant weighed somewhere between 94 and 375 tons (85 and 340 tons). The largest blue whales found have been within this area – around 200 tonnes (180 tonnes).
Its body stretched to about 66 feet (20 meters) long. Blue whales can be longer – with some growing to more than 100 feet (30 meters) in length.
That means the newly discovered whale was “possibly the heaviest animal ever,” Collareta said, but “it was most likely not the longest animal ever.”
It weighs more in part because its bones are much denser and heavier than a blue whale, Amson explained.
These super-dense bones suggest the whale may have spent its time in shallow coastal waters, the authors said. Other littorals, like manatees, have heavy bones to help them stay close to the ocean floor.
Without the skull, it’s hard to know what the whale ate to maintain such a huge body, Amson said.
It’s possible that P. colossus foraged for food along the ocean floor, researchers said, or ate tons of krill and other small marine animals in the water.
But “I wouldn’t be surprised if this thing actually fed in a completely different way that we would never imagine,” Thewissen added.
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