Acutimitoceras prorsum (Schmidt, 1925) from the Protognathodus kockeli horizon at Kowala in the Holy Cross Mountains.

Acutimitoceras prorsum;  growth lines and outline of the shell.

Diagnoza

Conch aperture with radially running lateral margins and gentle ventral sinus; rounded conch venter with no signs of angulation.

Porównanie

The species does not fit the diagnostic character of the genus in respect to the conch form but the shape of aperture resembles that in the type species and this supports its ancestral position within the lineage. Apparently on this basis Korn (1981, 1994) classified it in Acutimitoceras by. All specimens from Kowala are flattened and fragmentary but some show the original geometry leaving little doubt that this is a generalized prionoceratid with an oval whorl cross section. The distinct growth lines are not so apparent in the German material illustrated by Korn (1981, 1994) but this may be due to exfoliation of the conch surface.

Autekologia

Występowanie geograficzne

Kowala.

Zasięg czasowy

P. kockeli horizon.

Materiały muzealne

ZPAL: Numerous crushed and fragmentary specimens covering slabs of tuffite.

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.