Diagnoza

Unlike the preceding species, the platform of sp elements is here always low, with sharp but low ridges (Fig. 11G). The width of the basal cavity (pit) is also significantly smaller than in the older species of the lineage (Fig. ). Identification of the species requires a sample of at least a dozen sp elements because of a rather wide population variability.

The rest of the apparatus also seems to be less robust than in the ancestral P inaequalis. It is a matter of convention whether to apply to theset wo forms specieso r chrono-subspeciesr ank. The widening of the platform, making it more symmetrical, and the reduction in size of the basal cavity took place between the deposition of beds represented by samples Dz-46 (Dz-23) andDz-45 (Dz-22). In the Kowala section the number of specimenso f Weyerognathrr.irs too low to provide a good record of evolution. Only in the Muhua section does there seem to be a gradual change in the basal cavity of the sp elements size that makes discrimination of the chronospecies quite arbitrary .  This character reaches a status comparable with that in Kowala sample Ko-30 (where I41 triangulus appears for the first time) or with Dzikowiec samples Dz-14 close to the top of the limestone Wangyou Formation.

The type population of the species comes from the sample taken 0-10 cm below the top of the Hangenberg Limestone at H6nnetal (Voges 1959: pl. 35 7 ,8). The transition from the ancestral I41irnequalis took place before the sedimentation of bed Ha 10 in this locality.

Porównanie

Autekologia

Występowanie geograficzne

Zasięg czasowy

Materiały muzealne

Literatura