Diagnoza

Elongated and rather robust P₁ element with relatively low cusp.

Porównanie

The geologically oldest populations of Branmehla from Łagów (sample ŁSł73-2) closely resemble the earliest Famennian Pluckidina lipperti  and that species is likely to be its ancestor. The main difference is in the morphology of the M element, which is higly arched in B. bohlenana (note that the geologically later Pluckidina lipperti from the K. crepida Zone exhibits the same tendency.

The transition from B. bohlenana to B. inornata is gradual and it is virtually impossible to delimit these species even if for most of their range they occur allopatrically. In the rather representive sample Ost-12 from the L. styriacus Zone some elements can be found that are indistinguishable from those of the type species of the genus. They grade into the modal morphology of B. bohlenana and are thus considered extreme morphologies within the same species. In fact, the morphology of B. inornata is typical mostly for juvenile specimens. In the course of ontogeny denticles are added without increasing the element height and as a result the dominantion of the cusp seems to disappear. Ontogenetic extension of the dorsal process is connected with its lateral bending, which gives it the characteristic appearance.

The species is rather variable, especially in respect to the denticulation of P₁ elements. Denticles are wide and short, densely distributed in some specimens , or elongate and sparsely distributed in others

Panderodella subrecta of Holmes from the Chattanooga Sshale may be conspecific and thus a senior synonym of the species.

Autekologia

Występowanie geograficzne

Possibly ancestral population in the K. crepida Zone at Wietrznia, the typical form from the C. quadrantinodosa Zone to the end of the Famennian at Łagów, Miedzianka, Kowala, Ostrówka, and Dzikowiec.

Zasięg czasowy

Materiały muzealne

1,664 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.