Biozonas de Rhynchonellida (Brachiopoda) del Toarciense de las Cordilleras Ibérica y Cantábrica (España)

Abstract

Nine biozones based in the distribution of species of the order Rhynchonellida areproposed for the Toarcian of the Iberian and Cantabrian Cordilleras. In the Iberian Cordillera theseven proposed biozones cover the whole Toarcian: The Cantabrica Biozone corresponds to the associations that occur in the basin prior to the Lower Toarcian Extinction Event; Bouchardi andBatalleri Biozones correspond to the renewal episode after the extinction; Pusilla, Marini and Goyi Biozones correspond to a further renewal, restricted almost entirely to this basin; andfinally, Cynocephala Biozone corresponds to the occurrence in the basin of wide distributed species of the Northwest European Province. In the Cantabrian Cordillera the Cantabrica Biozone can be recognized in the Lower Toarcian, but the brachiopods do not recover after theExtinction Event until the Variabilis Chronozone. The Renzi and Aff. distercica Biozones a redefined with the associations that colonize this area and other neighbouring basins. In the Aalensis Chronozone, the biogeographic homogenization allows to recognize the Cynocephala Biozone in both areas.