Article: A new cephalopod fauna from the Lower Carboniferous of east Cornwall
A collection of approximately three hundred small cephalopods from a site in the Lower Carboniferous of east Cornwall includes representatives of Gattendorfia sp., Gen. et sp. nov. A, Muensteroceras complanatum, M. cf. rotella, Ammonellipsites princeps, A. sp. aff. asiaticus, A. sp. indet. and Gen. et sp. nov. B. It is argued that the fauna is of an age later than those of the Hangenbergkalk ('cul') of Germany and possibly earlier than the late Tournaisian cephalopods of Belgium ('culla(alpha symbol)'). German conodont evidence, taken together with some from Belgium, demonstrates that there is a range of Tournaisian age (Tn 2a-Tn 3b ? in terms of the Belgian stratigraphy, or approximately the Siphonodella crenulata Zone in terms of conodonts) of which the cephalopod-based zonal standard makes no account. Certain North American (Mississippian) cephalopod faunas which show coincidences of cheiloceratacean (including gattendorfiid) and goniatitacean (including muensteroceratid and ammonellipsitid) forms have not found accommodation in the European zonal scheme. In the cases of the Chouteau limestone, Rockford limestone, and Walls Ferry limestone the evidence of conodonts suggests reference to that range of the Tournaisian where the European cephalopod standard fails.