Cephalomyidae is an

extinct Extinction is the termination of a kind of organism or of a group of kinds (taxon), usually a species. The moment of extinction is generally considered to be the death of the last individual of the species, although the capacity to breed and ...

family of

caviomorph 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 a ...

rodent Rodents (from Latin , 'to gnaw') are mammals of the order Rodentia (), which are characterized by a single pair of continuously growing incisors in each of the upper and lower jaws. About 40% of all mammal species are rodents. They are na ...

s from

South America South America is a continent entirely in the Western Hemisphere and mostly in the Southern Hemisphere, with a relatively small portion in the Northern Hemisphere at the northern tip of the continent. It can also be described as the southe ...

. The specific relationships of the family are uncertain, and affinities to both chinchilloid and cavioid rodents have been supported. Most recently, Kramarz in 2005 performed a

phylogenetic In biology, phylogenetics (; from Greek φυλή/ φῦλον [] "tribe, clan, race", and wikt:γενετικός, γενετικός [] "origin, source, birth") is the study of the evolutionary history and relationships among or within groups o ...

analysis supporting a relationship to the Cavioidea, as represented by

Eocardiidae The Eocardiidae are an extinct family of caviomorph rodents from South America. The family is probably ancestral to the living family Caviidae, which includes cavies, maras, and capybaras and their relatives. McKenna and Bell (1997) divided eoca ...

, although more recent analyses have placed them among the chinchilloids as relatives of the giant neoepiblemid rodents. McKenna and Bell (1997) questioned the validity of the family, placing the cephalomyid genera then known in

Dasyproctidae Dasyproctidae is a family of large South American rodents, comprising the agoutis and acouchis. Their fur is a reddish or dark colour above, with a paler underside. They are herbivore, herbivorous, often feeding on ripe fruit that falls from tree ...

, but Kramarz (2001) subsequently reasserted the distinctiveness of cephalomyids. Fossils of the family have been found in

Deseadan The Deseadan ( es, Deseadense) age is a period of geologic time (29.0–21.0 Ma) within the Oligocene epoch of the Paleogene to the Early Miocene epoch of the Neogene, used more specifically within the SALMA classification of South America. It fo ...

Colhuehuapian The Colhuehuapian age is a period of geologic time (21.0–17.5 Ma) within the Early Miocene epoch of the Neogene, used more specifically within the SALMA classification in South America. It follows the Deseadan and precedes the Santacrucian ag ...

Fray Bentos Fray Bentos () is the capital city of the Río Negro Department, in south-western Uruguay, at the Argentina-Uruguay border, near the Argentine city of Gualeguaychú, Entre Ríos, Gualeguaychú. Its port on the Uruguay River is one of the nation's ...

Deseado Deseado may refer to: Geographic names and features * Deseado (crater), a crater on the planet Mars * Deseado Department, a department in Santa Cruz Province, Argentina * Deseado Massif, a geological formation in Santa Cruz Province, Argentina * De ...

, Cerro Bandera and

Sarmiento Formation The Sarmiento Formation (Spanish: ''Formación Sarmiento''), in older literature described as the Casamayor Formation, is a geological formation in Chubut Province, Argentina, in central Patagonia, which spans around 30 million years from the mid- ...

s and the Colhué Huapí Member of

Argentina Argentina (), officially the Argentine Republic ( es, link=no, República Argentina), is a country in the southern half of South America. Argentina covers an area of , making it the second-largest country in South America after Brazil, th ...

and the Puca Group of

Bolivia , image_flag = Bandera de Bolivia (Estado).svg , flag_alt = Horizontal tricolor (red, yellow, and green from top to bottom) with the coat of arms of Bolivia in the center , flag_alt2 = 7 × 7 square p ...

.Cephalomyidae
at

Fossilworks Fossilworks is a portal which provides query, download, and analysis tools to facilitate access to the Paleobiology Database The Paleobiology Database is an online resource for information on the distribution and classification of fossil animals ...

.org

References

Further reading