In this article, a new genus, Frontanyamys, is defined based on the new species F. russelli. The genus is recorded from the lower Upper Eocene (Bartonian) beds AT Sant Jaume de Frontanya (NE Spain). This genus shows clear affinities with the previously described genera Zamoramys, Remys and Pairomys. They are therefore assembled in the family Remyidae (new rank). The remyids are characterised by the precocious development of high-crowned molars and retain a morphologically primitive dental pattern. The oldest remyids are found in the middle Eocene of Spain (Zamoramys) and are probably derived from a morphologically primitive protrogomorph rodent such as Corbarimys paisi. The last representatives of the family such as Remys and Pairomys developed a fully lophodont dental pattern.