The genus Heterostegina (nummulitidae, Foraminifera) in the Upper Miocene of southwestern Spain

Systematic study of specimens belonging to the genus Heterostegina from coq uilla levels in the basal sandstone unit of the Neogene series in the weste rn part of the Guadalquivir Basin (SW Spain). The specific determination of these specimens allows us to revise and emend the species Heterostegina go mez-angulensis PERCONIG. For the first time we describe and figure the micr ospheric generation of this species. The redescription of the megalospheric forms has permitted to differentiate two morphotypes. We discuss their chr onostratigraphic significance. (C) Editions scientifiques et medicales Else vier SAS.