| The Lower Carboniferous bivalves of the Vegamián and Genicera formations are described, followed by a brief discussion on palaeoenvironmental and palaeogeographical aspects. The black shales of the Vegamián Fm. (Tournaisian) yield a peculiar association of euchondriid taxa (Euchondria wagneri sp. nov., Eu. cf. losseni, Eu. cf. bilstonensis, and euchondriids under open nomenclature) and Chaenocardia? carbonifera. This association displays Central-European Kulm-type character, but other typical taxa from the German Kulm are missing in this environment, especially the posidoniids, actinopteriids and pterinopectinids. The light coloured sediments of the Genicera (or Alba) Fm. yield bivalves in slightly greater diversity which include rare palaeotaxodonts,... |
