The occurrence of Ramys cf. perezi in the Miocene sequences of the Central Ebro Basin allows to locate the Aragonian-Vallesian transition (Late Miocene) in the alluvial and lacustrine sequences which make up the upper part of the basin sediments in the Sierra Alcubierre. These new data determine the age of the upper genetic unit defined in the central basin sectors, and mark the relationships between the Ebro Basin faunal assemblages and those from other Spanish basins included in the Central Iberian palaeobiogeographic province (e.g. Teruel and Duero Basins).