wood rat nutria sand rat abrocome rat chinchilla capybara agouti cotton rat murine hamster sewellel paca Dasyprocta aguti placental mountain paca jerboa marmot Aplodontia rufa cavy Myocastor coypus mountain beaver hedgehog beaver mole rat chinchilla rat Florida water rat placental mammal gerbille jumping mouse rat Rodentia water rat Sigmodon hispidus New World mouse porcupine viscacha Dolichotis patagonum muskrat Neofiber alleni musquash Ondatra zibethica prairie marmot Lagostomus maximus capibara coypu wood-rat Chinchilla laniger eutherian mara order Rodentia Cuniculus paca dormouse chinchilla mountain chinchilla chinchillon round-tailed muskrat eutherian mammal gnawer squirrel mountain viscacha mouse lemming prairie dog Hydrochoerus hydrochaeris gerbil