Posttornoceras (or Xenosporadoceras) posthumum (Wedekind, 1918) from the D. trigonica Zone at Kowala in the Holy Cross Mountains.

Diagnoza

Suture with wide, convex ventrolateral saddle and acute lateral saddle.

Porównanie

The original drawing of the suture by Wedekind (1918) does not show the characteristic, advanced appearance of the lateral saddle, but its tracing on the holotype photograph rather closely approaches the Kowala specimens. There was proposed a neotype for this species and illustrated its suture as well as the specimen . The conch ornamentation, visible in specimen IG 284.II.926 shows small auricles and probably shallow ventral sinus associated with longitudinal striae, features typical of Xenosporadoceras ademmeri Korn, 2002 from the P. annulata fauna at Kattensiepen. The main difference is in a more flattened conch and less derived suture in the mid Famennian species. Whether this is the same lineage characterized by longitudinally striated conchs or rather a case of convergence has to be settled out.

Autekologia

Występowanie geograficzne

Kowala.

Zasięg czasowy

D. trigonica Zone.

Materiały muzealne

ZPAL: 10 specimens.

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.