Giant rodents are nothing new. I myself create large rodents all the time thanks to my growth rays. However, it looks like Mother Nature has decided to try to trump me once again, with the discovery of Josephoartigasia monesi, a rodent that lived 4 million years ago. Weighing between 1700 and 3000 pounds, it is far bigger than anything I have created. But not for long! Inspired by this fossil treat, we shall soon witness the growth of Mega-Rats, whose large size will crush houses! I regret lagging so far behind in the giant rodent industry, and hopefully the newly created Mega-Rats will once again put me back on top. These ROUSes are the perfect bragging rights animal when you get together with your fellow mad scientists to show off. Take that, Dr. Von Wonkenberg! Nice albino chimp, Dr. Frank, too bad it was crushed by my Mega-Rats! MuHAHAHAHAHAHAHA! Even better, I’ll revive these Josephoartigasia monesi and begin breeding them as well. You can never have enough giant rodents.
Here is the news article:
Scientists: Extinct rodent weighed a ton
By RAPHAEL G. SATTER, Associated Press Writer Wed Jan 16, 10:06 PM ET
LONDON – Eeek! Imagine a rodent that weighed a ton and was as big as a bull. Uruguayan scientists say they have uncovered fossil evidence of the biggest species of rodent ever found, one that scurried across wooded areas of South America about 4 million years ago, when the continent was not connected to North America.
A herbivore, the beast may have been a contemporary, and possibly prey, of saber-toothed cats — a prehistoric version of Tom and Jerry.
For those afraid of rodents, forget hopping on a chair. Its huge skull, more than 20 inches long, suggested a beast more than eight feet long and weighing between 1,700 and 3,000 pounds.
Although British newspapers variously described it as a mouse or a rat, researchers say the animal, named Josephoartigasia monesi, actually was more closely related to a guinea pig or porcupine.
“These are totally different from the rats and mice we’re accustomed to,” said Bruce Patterson, the curator of mammals at the Field Museum in Chicago, adding that it was the biggest rodent he had ever heard of.
An artist’s rendering showed a creature that looked like a cross between a hippopotamus and guinea pig.
The fossil was found in 1987 about 65 miles west of the capital of Montevideo, near the vast River Plate estuary — a muddy waterway separating Uruguay from Argentina that empties into the South Atlantic. That area is site of ancient riverbanks and other deposits where fossils have been found, he said.
An Argentine fossil collector identified as Sergio Viera donated the skull to Uruguay’s National History and Anthropology Museum nearly two decades ago, said museum director Arturo Toscano.
It spent years hidden away in a box at the museum and was rediscovered by curator Andres Rinderknecht, who enlisted the help of fellow researcher Ernesto Blanco to study it.
Blanco told The Associated Press he was shocked when he first came face to face with the fossil, saying it looked even bigger than a cow skull.
“It’s a beautiful piece of nature,” he said in an interview. “You feel the power of a very big animal behind this.”
Blanco said the skull’s shape and the huge incisors left no doubt they were dealing with a rodent, but he cautioned that the estimate of the animal’s bulk was imprecise.
The extinct rodent clearly outclassed its nearest rival, the Phoberomys, found in Venezuela and estimated to weigh between 880 and 1,500 pounds.
Blanco said the rodent was far more enormous than any South American rodent alive today, surpassing even the present-day capibara that can weigh up to 110 pounds.
He said the animal’s teeth pointed to a diet of aquatic plants.
“From what we can tell, we know it was a herbivore that lived on the shores of rivers or alongside streams in woodland areas,” Rinderknecht told the AP. “Possibly it had a behavior similar to other water-faring rodents that exist today, such as beavers, which split their time between land and water.”
But he said the rodent appears to have had no tail, adding that follow-up studies are being planned to better determine its diet and other traits.
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.
Little trace of big rodent is left. Its closest surviving cousin, the pacarana, is endangered. The sharp-clawed 33-pound 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 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 in the developing world such as Uruguay’s — which is so strapped for cash it has been unable to hold public exhibitions since 2000.
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Associated Press writers Raul Garces and Alfonso Castiglia contributed to the report from Montevideo, Uruguay.
The largest fossil rodent
Andrés Rinderknecht1, R. Ernesto Blanco2
Abstract
The discovery of an exceptionally well-preserved skull permits the description of the new South American fossil species of the rodent, Josephoartigasia monesi sp. nov. (family: Dinomyidae; Rodentia: Hystricognathi: Caviomorpha). This species with estimated body mass of nearly 1000kg is the largest yet recorded. The skull sheds new light on the anatomy of the extinct giant rodents of the Dinomyidae, which are known mostly from isolated teeth and incomplete mandible remains. The fossil derives from San José Formation, Uruguay, usually assigned to the Pliocene–Pleistocene (4–2Myr ago), and the proposed palaeoenvironment where this rodent lived was characterized as an estuarine or deltaic system with forest communities.
Choice size quote:
In Reynolds (2002), the body mass of the giant extinct rodent Castoroides was estimated based on skull length, obtaining a maximum value of 200kg. If we apply the same method (with the same allometric relation) to J. monesi, we obtain a mean body mass of 1400kg with a standard deviation of 533kg and extreme values of 716 and 2250kg.
Skull comparison:
(that’s a pacarana, a capybara, and J. monesi for you non-scientists)
