Lewis Smith, Environment Reporter
The rodent, Josephoartigasia monesi, was uncovered by Andrés Rinderknecht and Ernesto Blanco. It has been nicknamed Mighty Mouse and is thought to have been similar to the capybara and pacarana, much smaller creatures that are still found in South America. Capybaras are the biggest living rodents at just over 60kg fully grown, while pacaranas weigh 15kg. The common rat weighs about 300g.