Gatunek typowy
Scaphignathus velifera Helms, 1959 from the mid Famennian of the Saalfeld area. 

Opis

Diagnosis. — Strongly asymmetric icrion in P1 elements, with tubercles of lateral and middle rows at approximately the same level, high free blade.

Remarks. — Scaphignathus differs from Alternognathus mainly in virtually equal height of tubercles of the platform and those of the corresponding part of the blade. In fact, at early stages of the ontogeny this is not a true platform but rather an icrion. This difference is apparent even in the geologically oldest samples with species of those genera co-occurring (e.g., J-24), although some specimens remain difficult to tell apart. There was probably no difference in the apparatus structure between those erliest members of the lineage. In geologically younger samples two kinds of P2 elements seem to occur, one with a rather generalized morphology belonging to Alternognathus and the other with a very regular and low denticulation, probably representing Scaphignathus. Early occurrences of Scaphignathus in the Holy Cross Mountains differ from those from younger strata in a much narrower icrion. In the icrion being developed dorsally mostly on one side, the P1 elements exhibit an axial symmetry, although some bending of the blade allows recognition of particular members of the mirror image pair. 

Synonimy

Zasięg czasowy

Literatura

Dzik, J. 2006. The Famennian "Golden Age" of conodonts and ammonoids in the Polish part of the Variscan sea. Palaeontologia Polonica 63, 1-359.