Caviidae

Caviidae, the cavy family, comprises nineteen species in seven genera across three subfamilies, native to South America, where it lives in habitats from moist savanna to thorn forest and scrub desert. Members have short, heavy bodies, large heads and typically no visible tail, ranging in size from small cavies around twenty two centimeters and three hundred grams up to the capybara, the largest living rodent at one hundred six to one hundred thirty four centimeters and thirty five to sixty six kilograms. The family includes the wild cavies and their domesticated descendant the guinea pig, and social structure varies widely, from promiscuous cavies to monogamous maras and capybaras living in groups of about ten.