The Dinomyidae are a

family Family (from la, familia) is a group of people related either by consanguinity (by recognized birth) or affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its members and of society. Idea ...

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 sou ...

hystricognath The Hystricognathi are an infraorder of rodents, distinguished from other rodents by the bone structure of their skulls. The masseter medialis (a jaw muscle) passes partially through a hole below each eye socket (called the infraorbital foramen) ...

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 n ...

s: the dinomyids were once a very speciose group, but now contains only a single living species, the

pacarana The pacarana (''Dinomys branickii'') is a rare and slow-moving hystricognath rodent indigenous to South America. Native Tupi people call it the ''pacarana'' (false paca) because it is superficially similar to the paca, a different rodent which is ...

. Several of the extinct dinomyids were among the largest rodents known to date; these included the

bison Bison are large bovines in the genus ''Bison'' (Greek: "wild ox" (bison)) within the tribe Bovini. Two extant and numerous extinct species are recognised. Of the two surviving species, the American bison, ''B. bison'', found only in North A ...

-sized ''

Josephoartigasia monesi ''Josephoartigasia'' is an extinct genus of enormous dinomyid rodent from the Early Pliocene to Early Pleistocene of Uruguay. The only living member of Dinomyidae is the pacarana. ''Josephoartigasia'' is named after Uruguayan national hero Jos ...

'' and the smaller ''

Josephoartigasia magna ''Josephoartigasia'' is an extinct genus of enormous dinomyid rodent from the Early Pliocene to Early Pleistocene of Uruguay. The only living member of Dinomyidae is the pacarana. ''Josephoartigasia'' is named after Uruguayan national hero Jos ...

''. The dinomyids are thought to have occupied

ecological niche In ecology, a niche is the match of a species to a specific environmental condition. Three variants of ecological niche are described by It describes how an organism or population responds to the distribution of resources and competitors (for ...

s associated with large grazing mammals due to their ability to compete with the native ungulates of South America. On the other side, they could feed on aquatic or swampy plants along the ancient rivers. These large forms disappeared after the formation of a connection to North America. The modern pacarana is only modest in size, considerably smaller than the

capybara The capybaraAlso called capivara (in Brazil), capiguara (in Bolivia), chigüire, chigüiro, or fercho (in Colombia and Venezuela), carpincho (in Argentina, Paraguay and Uruguay) and ronsoco (in Peru). or greater capybara (''Hydrochoerus hydro ...

. The Neoepiblemidae, an entirely extinct family, may actually be part of the Dinomyidae; both groups are undoubtedly closely related.

Genera

*Family: Dinomyidae **†'' Agnomys'' ''incertae sedis'' **†'' Borikenomys'' - ''incertae sedis''? **†'' Pseudodiodomus'' ''

incertae sedis ' () or ''problematica'' is a term used for a taxonomic group where its broader relationships are unknown or undefined. Alternatively, such groups are frequently referred to as "enigmatic taxa". In the system of open nomenclature, uncertain ...

'' **Subfamily: Dinomyinae ***'' Dinomys'' -

***†'' Telodontomys'' **Subfamily: † Eumegamyinae ***†'' Briaromys'' ***†'' Colpostemma'' ***†'' Doellomys'' ***†'' Eumegamysops'' ***†''

Eumegamys ''Eumegamys'' is an extinct genus of dinomyid rodent from the late Miocene and Pliocene of Brazil (Solimões Formation), Venezuela (Urumaco Formation, Urumaco) and Argentina (Ituzaingó Formation The Ituzaingó Formation ( es, Formación Ituza ...

'' ***†'' Gyriabrus'' ***†'' Josephoartigasia'' ***†'' Orthomys'' ***†'' Pentastylodon'' ***†'' Pseudosigmomys'' ***†'' Telicomys'' ***†'' Tetrastylus'' **Subfamily: † Potamarchinae ***†'' Eusigmomys'' ***†'' Olenopsis'' ***†'' Potamarchus'' ***†'' Scleromys'' ***†'' Simplimus''

References

* {{Taxonbar, from=Q135889 Rodent families Hystricognath rodents Extant Miocene first appearances Taxa named by Wilhelm Peters