Dolichotis patagonica; Print; Mara (mammal); The maras are a genus (Dolichotis) of the cavy family of rodents. They are the sole extant representatives of the subfamily Dolichotinae. These large relatives of guinea pigs are common in the Patagonian steppes of Argentina; but also live in Paraguay and elsewhere in South America. Maras are the fourth-largest rodent in the world; after capybaras; beavers; and porcupines; reaching about 45 cm (18 in) in height.; 1700-1880