Pinacognathus? praesulcatus (Sandberg, 1972) from the D. trigonica Zone at Kowala in the Holy Cross Mountains - P₁ elements.

Pinacognathus? praesulcatus - P₁ element.

Diagnoza

Porównanie

Material at my disposal is rather poor and only sample Ko-116 contains enough specimens of various ontogenetic age to see their variability. It appears that juveniles have a platform usually separated from the blade by a deep depression and the element has the greatest width at the dorsal end of the platform. In mature specimens the middle part of the platform is the widest and it is almost flat with the denticles of the blade somewhat elevated. Elements show mirror symmetry that makes unlikely any relationship to Alternognathus. Also the flat or somewhat inverted basal cavity makes it different from Alternognathus, where the base remains slightly concave and the margin of the basal cone remains sharp. Variability is expressed mostly in more or less robust transverse ribbing of the platform and in the dorsal margin of the platform, in juveniles being thin and wide or rather narrow and robustly tuberculated. The apparatus remains unknown.

Autekologia

Występowanie geograficzne

Kowala and Dzikowiec.

Zasięg czasowy

D. trigonica Zone. 

Materiały muzealne

ZPAL: 17 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.