Eocardiidae

The Eocardiidae are an extinct family of caviomorph rodents from South America. The family is probably ancestral to the living family Caviidae,^[1] which includes cavies, maras, and capybaras 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).^[2]

Eocardiidae Temporal range: Early-Mid Miocene (Colhuehuapian-Friasian) ~21.0–15.5 Ma PreꞒ Ꞓ O S D C P T J K Pg N
Skeletal restoration of Eocardia
Scientific classification
Kingdom:	Animalia
Phylum:	Chordata
Class:	Mammalia
Order:	Rodentia
Superfamily:	Cavioidea
Family:	†Eocardiidae Ameghino 1891
Subfamilies and genera
†Eocardiinae †Chubutomys †Phanomys †Schistomys †Eocardia †Matiamys †Neophanomys †Luantinae †Asteromys †Luantus

Fossils of the family were found in the Colhuehuapian to Friasian Pinturas, Sarmiento, Santa Cruz, Río Jeinemeiní and Collón Curá Formations of Argentina and the Cura-Mallín Group of Chile.^[3]