Chinchilloidea

Caviomorpha Temporal range: Oligocene–Recent PreЄ Є O S D C P T J K Pg N
Capybara
Scientific classification
Kingdom:	Animalia
Phylum:	Chordata
Class:	Mammalia
Order:	Rodentia
Infraorder:	Hystricognathi
Parvorder:	Caviomorpha Wood, 1955
Families
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Caviomorpha is the rodent infraorder or parvorder that unites all New World hystricognaths. It is supported by both fossil and molecular evidence. The Caviomorpha was for a time considered to be a separate order outside the Rodentia, but is now accepted as a genuine part of the rodents. Caviomorphs include the extinct Heptaxodontidae (giant hutias) and extant families of chinchilla rats, hutias, guinea pigs and the capybara, chinchillas and viscachas, tuco-tucos, agoutis, pacas, pacaranas, spiny rats, New World porcupines, coypu and octodonts (Vassallo and Antenucci, 2015).

The first known rodent fossils in South America are represented by the three taxa Cachiyacuy contamanensis, C. kummeli, and Canaanimys maquiensis, as well as teeth from Eobranisamys sp. (Dasyproctidae) and Eospina sp., the latter two found also in the Santa Rita fauna from the late Eocene or early Oligocene. By the late Oligocene, all superfamilies and most families of caviomorphs are present in the fossil record.