Researchers believe they have discovered the largest rodent ever, though it died out some two million years ago.

According to BBC News, authors of a study published in the Journal of Anatomy said the Josephoartigasia monesi was the size of a bull and had tusk-like front teeth it used for several different purposes. They used a CT scan on its skull to perform computer simulations to determine how the rodent used its teeth.

The scans indicated J. monesi's front teeth were about 30cm long and were used in self defense, digging and tearing into prey. The simulations also suggested the rodent's bite was comparable in power to a tiger's.

The J. monesi skull was initially discovered in Uruguay in 2007. It likely lived in the Pliocene period, a time when the first mammoths lived, as did several large mammals. 

"We concluded that Josephoartigasia must have used its incisors for activities other than biting, such as digging in the ground for food, or defending itself from predators," study lead author Philip Cox, of the Centre for Anatomical and Human Sciences, said in a press release. This is very similar to how a modern day elephant uses its tusks."