Hypsodont Myomiminae (Gliridae, Rodentia) from five new localities in the Lower Miocene Tudela Formation (Bardenas Reales, Ebro Basin, Spain) and their bearing on the age of the Agenian-Ramblian boundary

The hypsodont Myomiminae Daams, 1981 (Gliridae) from the lower part of the Tudela Formation (Ebro Basin) are described. Five localities (CH1, CA2, CA3, CA4 and CC1) of this formation contain remains of the hypsodont genus Armantomys de Bruijn, 1966 and CC1 has also yielded Praearmantomys de Bruijn, 1966. Despite the poor material, we can identify the taxa A. cf. bijmai, A. daamsi (de Visser in Álvarez-Sierra, Daams, Lacomba, López Martínez, Van Der Meulen, Sesé & De Visser, 1991), A. cf.parsani, A. cf. jasperi and cf. P. crusafonti, which are characteristic of the Agenian and Ramblian continental stages. These data allow identification of the Agenian-Ramblian boundary in the Tudela Formation, and provide a calibration of this boundary on the basis of available magnetostratigraphic information.