Diagnoza

Porównanie

Siphonodella sp. [aff. S. crenulata (Cooper, 1939)]. - The extremely asymmetrical, robust sp elements from samples Dz-6 andDz-66, I) do not seem to represent end-members of the population variability of S. duplicata. They are either angularly bent, with resulting triangular shape of the platform or with the vertical platform margins continuing into ridges that point towards the cusp. In the latter  character and widely extended posterior lobe of the platform they resemble much later S. crenulata and may appear ancestral to it. As mentioned above, they me arbitrarily proposed to be matched in the apparatus with co-occurring robust symmetry transition elements. Another interpretation of this species, which occurs also in the Muhua section, has been offered by Ji et al. (1989: p. 99, pl. 14: 5-8). According to them, this is a connecting link between S. duplicate and '5.' lobata. In fact, there are associated symmetry transition series elements of Dinodus (to which the latter species is here transfened) in the Dzikowiec samples and, if their evolutionary interpretation is correct, quite another restoration than that proposed hoe of these species apparatuses would be necessary.

Autekologia

Występowanie geograficzne

Zasięg czasowy

Materiały muzealne

Literatura