Resumen de Identificación de Bournonia Gardonica (Toucas, 1907) en el Cretácico Superior del Barranco de las Cuevas (Patones, Madrid)
Manuel Segura Redondo, J. Gil, Josep Maria Pons Muñoz
Sandy and dolomitic Cretaceous rocks, lying uncort'ormably on Ordovician slates, crop out at the southern margin of the Central System in the Community of Madrid. Precise dating of theserocks has always been problematical due to the lack of characteristic marine fossils. The recent study of a stratigraphical profile at Barranco de las Cuevas, near Patones, reported some levels containing a rich rudist assemblage in the middle carbonade interval of the Hortezuelos Fm. The rudists have been identified as Bournonia gardonica (Toucas), a characteristic radiolitid of Coniacian age, first described in southern France, known from Italy and reported now for the first time in the Iberian Peninsula. These fossils are the only rudists identified so far at the species level in the Community of Madrid. They allowed the precise dating of the lower part of the Hortezuelos Fm as Coniacian in age, and provide further arguments to consider the section as ageological and palaeontological important site that should be protected and preserved.
