Hippo sized rat fossil discovered in Uruguay, Rat Hippo or Hippo Rat?

Largest fossil rodent species Josephoartigasia monesi, discovered in Uruguay, with an estimated body mass of one tonne.

The fossilised skull of a one tonne rat the size of a hippopotamus has been unearthed in South America.

The creature, nicknamed Mighty Mouse, is believed to have lived around 4 million years ago, weighed about a tonne and ate mostly soft vegetation. It was so big that it probably spent much of its life semi-submerged in water, like a hippo, to reduce the stresses caused by its vast size. Its skull was discovered in a boulder that fell away from a cliff in the San Jose region of Uruguay.

However, the importance of the find was not immediately realised and the fossil was stored in the Montevideo national history museum for many years.

Known by its Latin name, Josephoartigasia monesi, the vegetarian rat looked like a cross between a guinea pig and a beaver. The rodent was estimated to be around three metres (10ft) long and 1.5 metres tall.