Article: Lower Carboniferous conodont faunas from Ravenstonedale, Cumbria
Conodont faunas from the Lower Carboniferous, Courceyan-Holkerian Stages, of Ravenstonedale are described. Three zones, the Taphrognathus, Cloghergnathus, and Cavusgnathus Zones, are recognized in the Chadian-Holkerian strata and one fauna, Fauna A, in the mid-Courceyan. These zones and the Fauna are correlated with the standard British Stages and with the American classic sections. The faunas are typical of the shallow water facies of the Lower Carboniferous and are dominated by the genera Taphrognathus, Clydagnathus, Cloghergnathus, and Cavusgnathus, which characteristically occur in intertidal and shallow subtidal environments. These shallow-water faunas are joined by deeper-water immigrants only in the Arundian but, even at this level, they are the dominant elements, indicating only a slight water depth increase. The absence of the deeper-water genera Gnathodus and Siphonodella adds difficulty to the correlation of this succession with goniatite-bearing sequences, but correlation with the Avon Gorge and with shallow-water facies in the north of England is possible. Three species, Apatognathus asymetricus, A. scandalenis, and Cloghergnathus carinatus are proposed as new taxa.