Posttornoceras balvei Wedekind, 1910? (or Sporadoceras sp.) from the P. trachytera Zone at Łagów in the Holy Cross Mountains.

Posttornoceras balvei  (or Sporadoceras sp.); sutures and outline of the shell.

Diagnoza

Suture with tips of all lobes pointed and a narrow ventrolateral saddle.

Porównanie

Serial internal thickenings of the conch developed probably parallel to the aperture, with typically tornoceratid auricles. Despite the inferred form of aperture, the specimens studied may actualy belong to Sporadoceras, although restriction of shell thickenings to the venter make it different from species of that genus. Original specimens of both P. balvei (Wedekind 1918, pl. 17: 5) and the probably related P. sodalis Becker, 1995 (Bogoslovsky 1971, pl. 4: 8) show a high whorl expansion rate, much higher than in the Łagów specimens. This may be related to their early ontogenetic age but is not completely consistent with this identification.

Autekologia

Występowanie geograficzne

Łagów-Dule.

Zasięg czasowy

Probably the C. marginifera and P. trachytera Zones. 

Materiały muzealne

ZPAL: 3 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.