The Dinomyidae are a

family Family (from ) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). It forms the basis for social order. Ideally, families offer predictabili ...

South America South America is a continent entirely in the Western Hemisphere and mostly in the Southern Hemisphere, with a considerably smaller portion in the Northern Hemisphere. It can also be described as the southern Subregion#Americas, subregion o ...

n hystricognath

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

s: the dinomyids were once a very speciose group, but now contains only a single living species, the pacarana. Several of the extinct dinomyids were among the largest rodents known to date; these included the

bison A bison (: bison) is a large bovine in the genus ''Bison'' (from Greek, meaning 'wild ox') within the tribe Bovini. Two extant taxon, extant and numerous extinction, extinct species are recognised. Of the two surviving species, the American ...

-sized '' Josephoartigasia monesi'' and the smaller '' Josephoartigasia magna''. 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 Resource (biology), resources an ...

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 capybara or greater capybara (''Hydrochoerus hydrochaeris'') is the largest living rodent, native to South America. It is a member of the genus '' Hydrochoerus''. The only other extant member is the lesser capybara (''Hydrochoerus isthmi ...

. 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 is a term used for a taxonomy (biology), 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, uncertainty ...

'' **Subfamily: Dinomyinae ***'' Dinomys'' - pacarana ***†'' Telodontomys'' **Subfamily: † Eumegamyinae ***†'' Arazamys'' ***†'' Briaromys'' ***†'' Colpostemma'' ***†'' Doellomys'' ***†'' Eumegamysops'' ***†'' Eumegamys'' ***†'' Gyriabrus'' ***†'' Isostylomys'' ***†'' Josephoartigasia'' ***†'' Orthomys'' ***†'' Pentastylodon'' ***†'' Pseudosigmomys'' ***†'' Telicomys'' ***†'' Tetrastylus'' **Subfamily: † Potamarchinae ***†'' Eusigmomys'' ***†'' Olenopsis'' ***†'' Potamarchus'' ***†'' Scleromys'' ***†'' Simplimus''

References

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