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) in South America.Eumegamys at Fossilworks.org Its skull was 50 cm (1.64 ft) long.
References
Further reading McKenna, Malcolm C., and Bell, Susan K. 1997. Classification of Mammals Above the Species Level. Columbia University Press, New York, 631 pp.