Caradoc through Early AshgillBrachiopods from the Central-Iberian zone (Central Spain)

Abstract

Caradoc through early Ashgill brachiopods from the Central-Iberian Zone, representing the latest cold water brachiopodassociations of the West European Platform developed on the North-African Gondwana margin, have been studied. Twenty one brachiopod taxa, including two new species (Tafilaltia brevimusculosa and Hedstroemina almadenensis), collected from stratigraphic sections in Corral de Calatrava, Almadén, Guadalupe and Valencia de Alcántara (Ciudad Real and Cáceres provinces in Spain) are described and their stratigraphic significance is assessed. The oldest brachiopods studied, from the ironstone above the “Neseuretus Sandstone” and the basal “Cantera Shales”, are considered coeval with those from the Soudleyan iron oolite widely spread in Ibero-Armorica. The youngest brachiopods have been collected from the uppermost “Bancos Mixtos” and the “Calymenella Quartzite”, of Pusgillian age. All those associations are dominated by Mediterranean forms of the families Heterorthidae, Draboviidae, Orthostrophiinae and Aegiromeninae, but the highest horizons of the “Bancos Mixtos” have also yielded rare occurrences of forms more typical of the northern temperate continents (Strophomenidae, Sowerbyellinae, Leptestiidae) within a typically Mediterranean association. Those northern forms are considered to represent a first pulse of immigration, occurring shortly before the environmental turnover that promoted the final replacement of the cold waters associations by the Nicolella Community across the West European Platform.