Opis

Elements of the apparatus with very thin, finely denticulated blades and very wide basal cavity; little shape differentiation within the apparatus.

Despite originally suggested icriodontid affinities, the apparatus of Playfordia primitiva (Bischoff & Ziegler, 1957) is basically different from those of the icriodontids in do not showing distinction between the platform series and the symmetry transition series elements, as discussed above. Some remote similarities to the Early Carboniferous ancestral Eotaphrus can be traced, but there is too long time hiatus separating these genera. Symmetrical elements of Playfordia resemble superficially Ancyrognathus ancyrognathoideus (Ziegler, 1958) but to make them homologous would require that the basal cone of Playfordia is an extremely thin platform derived from that of Ancyrognathus. They also differ in surface ornamentation, which in the ancyrognathids, as well as in Dinodus is covered with cell imprints and not finely tuberculated. Moreover, the stratigraphic occurrence of Playfordia makes it derivation from Ancyrognathus unlikely.

Synonimy

Zasięg czasowy

Literatura

Dzik, J. 1997. Emergence and succession of Carboniferous conodont and ammonoid communities in the Polish part of the Variscan sea. Acta Palaeontologica Polonica 42, 57-170.

Dzik, J. 2002. Emergence and collapse of the Frasnian conodont and ammonoid communities in the Holy Cross Mountains, Poland. Acta Palaeontologica Polonica 47 (4): 565-650