Fossil remains of 2,000-pound rodent found

Cat vs. mouse vs. bird?
The creature may have been a contemporary to the saber-toothed cats and giant carnivorous birds that roamed the area millions of years ago, but Blanco said it was not clear whether such predators had the power necessary to bring down the huge beast.

“This investigation began about a year and a half ago but it’s still not complete,” Rinderknecht said, adding that the next step may be a CT scan of the skull “to better determine its interior dimensions.”

The research by Rinderknecht and Blanco was published Wednesday in this week’s issue of biological research journal, Proceedings of the Royal Society B.

Scientists uninvolved with the finding agreed that this was one really big rodent.

“I think it’s a very important discovery — it is certainly an immense animal,” said Mary Dawson, a paleontologist at the Carnegie Museum of Natural History in Pittsburgh. She said it and other rodents grew bigger by filling the ecological niche taken elsewhere by rhinoceroses and hippopotamuses.

“They got large taking the role of some herbivores that were not present at that time — South America was still an island continent,” she said. But when North and South America were linked about 3 million years ago, the rodents were swamped by North American animals and eventually died out.

“It’s too bad they’re extinct, I’d love to see those things,” she said.

Patterson said its discovery gave scientists more insight into the fauna of the prehistoric South American continent, when it hosted creatures such as marsupial predators and hoofed animals known to scientists as archaic ungulates.

“These were things with trunks on their noses, huge claws on their hands, they look like somebody just made them up,” he said.

Few traces of big rodents are left today. Josephoartigasia monesi's closest surviving cousin, the pacarana, is endangered. That sharp-clawed 33-pound (15-kilogram) rodent lives in the hills around the Andes Mountains. It is considered among the largest living rodents, but its slow rate of reproduction — and reputation among humans as a tasty treat — means its prospects are grim.

Blanco said he was thrilled with the discovery of the huge rodent after so many years.

“When you start to open all these boxes, often times you find all kinds of interesting pieces of paleontology,” he said.

“The collector alerted us that it was an important fossil,” Toscano said, adding that the skull remains carefully packed in a box in the museum’s paleontology collection.

Both Blanco and Toscano said they hoped the find would attract more resources to museums such as the one in Uruguay — which is so strapped for cash it has been unable to hold public exhibitions since 2000.

Associated Press writers Raul Garces and Alfonso Castiglia contributed to the report from Montevideo, Uruguay.

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