The largest rodent ever was a giant guinea pig as big as a buffalo, which lived in South America eight million years ago, researchers say this week in the journal Science.

More than twice as heavy as the previous record holder, it was more than 10 times the size of today's largest living rodent, the South American Capybara. This giant rodent grazed on grasses, which it must have eaten in large amounts to support its great size.

It had fur, a smooth head with small ears and eyes, and a large tail that allowed it to balance on two hind legs to watch out for predators. When resting on its hind legs, in the posture used by many of its modern-day relatives, it would have stood taller than the typical basketball player. An exterminator's nightmare, the creature weighed 1,545 pounds and was more than 700 times heavier than its modern cousins.

An almost complete fossil was unearthed at Urumaco in Venezuela and analysis of it has enabled scientists to build up a picture of the beast. Scientists in Germany, Venezuela and the United States who made the discovery have called the creature Phoberomys pattersoni - which means "fearsome mouse of Patterson," in honor of the late Professor Brian Patterson. He was the American paleontologist who was one of the first to study in the region in which the skeleton was found.

There were a lot of meat eaters around which probably preyed on the slow moving, plant eating giant. Some of the largest crocodiles ever, more than 10 meters (33 feet) long, were in the same location it was found. This weird looking titanic guinea pig also had to worry about large carnivores called marsupial cats, and huge flesh-eating birds called phorracoids.