Dasbergina trigonica (Ziegler, 1962) from its nominal zone at Ostrówka  in the Holy Cross Mountains and Dzikowiec  in the Sudetes - P₁ elements.

Dasbergina trigonica  - P₁ element.

Diagnoza

The basal cavity of P₁ element bifurcates anteriorly.

Porównanie

In successive samples in the upper part of the Dzikowiec section the anterior lobe of the basal cavity of the P₁ element, originally round (Dz-18), gradually becames more angular (Dz-10, Dz-17, Dz-20b) and then its tip narrows and the lobe bifurcates (Dz-19, Dz-47, Dz-4). This marks the transition from D. marburgensis to D. trigonica. This character shows a significant population variability and juveniles may show angular wide lobes even in samples from high above in the section (e.g., Dz-8).

The species occurs in the borehole Kowala.

Autekologia

Występowanie geograficzne

Kowala, Ostrówka and Dzikowiec.

Zasięg czasowy

Zone of its own. 

Materiały muzealne

ZPAL: 204 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.