Dinodus sp. n. - P₁, S₁, S₂ and M elements.

Diagnoza

Porównanie

These oldest Tournaisian Dinodus S elements differ from later elements of the same genus in not having any platform-like ridges at their bases; they thus probably belong to a new species. They are associated with strongly asymmetric P₁ elements that were proposed by Ji et al. ( 1989) to represent a transition between S. duplicata and 'S.' lobata. These two species differ rather profoundly in the morphology of the basal surface of the P₁ elements .

Another candidate among P₁ elements to be matched with S elements of Dinodus sp. n. are elements resembling S. duplicata morphology but much more primitive in being transitional to S. sulcata in the platform appearance. There are some problems with the P₂ location in this case as, along with a single large element of morphology fitting very well  Dinodus, there are several minute elements transitional in shape between elements attributed to S. carinthiaca and those interpreted as belonging to S. duplicata . It is unlikely that these are juvenile elements that would later in their histogeny have developed the morphology of the Dinodus P₁ elements. Perhaps at this stage of evolution the lineages of Dinodus and Siphonodella, although having developed different apparatuses, did not differ in P₁ element morphology.

Autekologia

Występowanie geograficzne

Zasięg czasowy

Materiały muzealne

ZPAL

Literatura

Dzik, J. 1997. Emergence and succession of Carboniferous conodont and ammonoid communities in the Polish part of the Variscan sea. Acta Palaeontologica Polonica 42, 57-170.