Caviidae
Caviidae, the cavy family, is composed of rodents native to South America and includes the domestic guinea pig, wild cavies, and the largest living rodent, the capybara. They are found across South America in open areas from moist savanna to thorn forests or scrub desert. This family of rodents has fewer members than most other rodent families, with 19 species in 6 genera in 3 subfamilies.
Largest organisms
The lion's mane jellyfish ("Cyanea capillata") is the largest cnidaria species, of the class Scyphozoa. The largest known specimen of this giant, found washed up on the shore of Massachusetts Bay in 1870, had a bell diameter of , a weight of . The tentacles of this specimens were as long as and were projected to have a tentacular spread of about making it one of the longest extant animals.
The largest roundworm, "Placentonema gigantissima", is a parasite found in the placentas of sperm whales which can reach up to in length.