Eocardiidae
Encyclopedia
The Eocardiidae are an extinct family of caviomorph
rodent
s from South America
. The family is probably ancestral to the living family Caviidae
(Kramarz, 2006), which includes cavies, mara
s, and capybara
s and their relatives. McKenna and Bell (1997) divided eocardiids into two subfamilies, Luantinae for two of the oldest genera (Asteromys and Luantus) and Eocardiinae for remaining genera. Kramarz (2006) has recommended the abandonment of these subfamilies, as the genera placed in Luantinae appear to represent basal eocardiids, rather than a specialized side branch. The latter hypothesis had been proposed by Wood and Patterson (1959).
Caviomorpha
Caviomorpha is the rodent infraorder or parvorder that unites all South American hystricognaths. It is supported by both fossil and molecular evidence.-Origin:...
rodent
Rodent
Rodentia is an order of mammals also known as rodents, characterised by two continuously growing incisors in the upper and lower jaws which must be kept short by gnawing....
s from South America
South America
South America is a continent situated in the Western Hemisphere, mostly in the Southern Hemisphere, with a relatively small portion in the Northern Hemisphere. The continent is also considered a subcontinent of the Americas. It is bordered on the west by the Pacific Ocean and on the north and east...
. The family is probably ancestral to the living family Caviidae
Caviidae
The cavy family is a family of rodents native to South America, and including the domestic guinea pig, wild cavies, and the capybara, among other animals...
(Kramarz, 2006), which includes cavies, mara
Mara (mammal)
The maras are a genus of the cavy family. They are the sole representatives of the subfamily Dolichotinae. These large relatives of guinea pigs are common in the Patagonian steppes of Argentina but live in other areas of South America as well such as Paraguay...
s, and capybara
Capybara
The capybara , also known as capivara in Portuguese, and capibara, chigüire in Venezuela, Colombia, and Ecuador ronsoco in Peru, chigüiro, and carpincho in Spanish, is the largest living rodent in the world. Its closest relatives are agouti, chinchillas, coyphillas, and guinea pigs...
s and their relatives. McKenna and Bell (1997) divided eocardiids into two subfamilies, Luantinae for two of the oldest genera (Asteromys and Luantus) and Eocardiinae for remaining genera. Kramarz (2006) has recommended the abandonment of these subfamilies, as the genera placed in Luantinae appear to represent basal eocardiids, rather than a specialized side branch. The latter hypothesis had been proposed by Wood and Patterson (1959).