What is the largest species of rodent?
Capybara
The capybara (Hydrochoerus hydrochaeris) is a mammal native to South America. It is the largest living rodent in the world. Also called chigüire, chigüiro (in Colombia and Venezuela) and carpincho, it is a member of the genus Hydrochoerus, of which the only other extant member is the lesser capybara (Hydrochoerus isthmius). Its close relatives include guinea pigs and rock cavies, and it is more distantly related to the agouti, the chinchilla, and the coypu. The capybara inhabits savannas and dense forests and lives near bodies of water. It is a highly social species and can be found in groups as large as 100 individuals, but usually lives in groups of 10–20 individuals. The capybara is not a threatened species but it is hunted for its meat and hide and also for grease from its thick fatty skin, which is used in the pharmaceutical trade.[2]
Josephoartigasia monesi
"J. monesi" replaced "Phoberomys pattersoni", a related and somewhat older species that lived in Venezuela during the Late Miocene, as the largest rodent. However, size comparisons are difficult because previous estimates of for "P. pattersoni" were based on fore and hind limb elements, which are not present in the "J. monesi" specimen.