First report of the mitrate Mitrocystella (Echinodermata, Stylophora) in the Middle Ordovician of the Crozon Peninsula, Brittany (France)

Abstract

The mid-Ordovician mitrocystitid mitrate Mitrocystella incipiens was one of the most widespread stylophorans in the high latitude Mediterranean Province, with occurrences in the Armorican Massif ( France), the Iberian Peninsula ( Portugal and Spain) and the Prague Basin ( Czech Republic), all restricted so far to the late Darriwilian ( Hustedograptus teretiusculus Zone). The description of this taxon in the Corréjou Member ( Postolonnec Formation) of the Crozon Peninsula (western Brittany, France) not only extends its spatial distribution within the Armorican Massif, but also its stratigraphic range into the mid-Darriwilian ( Didymograptus artus Zone). The remarkable preser vation of the new material and associated sedimentological evidence both suggest rapid burial by storm deposits.