Everybody thinks capybara was and is the biggest rodent ever but a species of capybara (extinct) named josephoartigasia monesi was way bigger and lived in north America woodlands (estimated) and is estimated at 770-3400lbs and estimated at 4.9 feet in hight and 9.8 in langth finally discovered in 2008 and i have to say this was no rodent you wanted to make mad