''Anchitheriomys'' is an extinct member of the

beaver Beavers are large, semiaquatic rodents in the genus ''Castor'' native to the temperate Northern Hemisphere. There are two extant species: the North American beaver (''Castor canadensis'') and the Eurasian beaver (''C. fiber''). Beavers ar ...

family,

Castoridae The family Castoridae contains the two living species of beavers and their fossil relatives. A highly diverse group of rodents within this family once roamed the earth, but only a single genus is extant today, '' Castor''. Characteristics C ...

. It inhabited

North America North America is a continent in the Northern Hemisphere and almost entirely within the Western Hemisphere. It is bordered to the north by the Arctic Ocean, to the east by the Atlantic Ocean, to the southeast by South America and the Car ...

and

Eurasia Eurasia (, ) is the largest continental area on Earth, comprising all of Europe and Asia. Primarily in the Northern and Eastern Hemispheres, it spans from the British Isles and the Iberian Peninsula in the west to the Japanese archipelago a ...

during the middle

Miocene The Miocene ( ) is the first geological epoch of the Neogene Period and extends from about (Ma). The Miocene was named by Scottish geologist Charles Lyell; the name comes from the Greek words (', "less") and (', "new") and means "less recen ...

. The name of the genus comes from ''

Anchitherium ''Anchitherium'' (meaning ''near beast'') was a fossil horse with a three-toed hoof. ''Anchitherium'' was a browsing (leaf eating) horse that originated in the early Miocene of North America and subsequently dispersed to Europe and Asia,(in Ch ...

'', an extinct genus of

horses The horse (''Equus ferus caballus'') is a domesticated, one-toed, hoofed mammal. It belongs to the taxonomic family Equidae and is one of two extant subspecies of ''Equus ferus''. The horse has evolved over the past 45 to 55 million yea ...

, and the

Greek Greek may refer to: Greece Anything of, from, or related to Greece, a country in Southern Europe: *Greeks, an ethnic group. *Greek language, a branch of the Indo-European language family. **Proto-Greek language, the assumed last common ancestor ...

word for mouse, μῦς (''mys''), thus meaning "''Anchitheriums mouse", because the fossils of both genera usually co-occur. Until recently, ''Anchitheriomys'' was placed in a closely related family of

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, the

Eutypomyidae Eutypomyidae is a family (biology), family of extinct rodents from North America and Eurasia thought to be related to modern beavers. References

Prehistoric rodent families Eocene first appearances Miocene extinctions {{paleo-rodent- ...

, but a partial skull shows similarities to another early beaver, ''

Agnotocastor ''Agnotocastor'' is an extinct member of the beaver family Castoridae. Unlike its modern relative, this species took the place of muskrats in the rivers of North America during the Oligocene The Oligocene ( ) is a geologic epoch of the Paleo ...

''.*

References

Prehistoric beavers Prehistoric rodent genera Oligocene rodents Prehistoric mammals of Europe {{paleo-rodent-stub