Gatunek typowy
Roundya plana Helms, 1959 from the Platyclymenia annulata Zone, Bohlen near Saalfeld.

Opis

Triramous in all S elements, M element with strongly bent, ribbon-like external process and transversely oriented undenticulated inner process.
This genus is unusual in that the denticulated and elongated process in its M elements is not the inner one, as in virtually all other ozarkodinid and prioniodontid conodonts, but the outer one. Such a bizarre morphology can be explained if the ancestor of Planadina was like Francodina franconica or Sweetodina lagoviensis in this respect, that is with both processes elongated and bearing low and wide denticles. Especially the denticulation of the ribbon-like process in the latter species is appealing as a possibly ancestral state because it forms a kind of undulating ridge. A mysterious aspect of this apparatus is that no undoubted P series elements have been identified (except for one questionable specimen of small size). A possibility emerges that P1-2 elements attained the same shape as the M elements. In fact some of them resemble platform series elements of Sweetodina. 

Synonimy

Zasięg czasowy

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.