A Re-interpretation of the Structure of Dictyonema flabelliforme Eichwald

The presence of a stolon-system of apparently normal dendroid type in Dictyonema flabelliforme has been demonstrated in sections of this graptolite in the Obolus conglomerate of Grönviken, Öland. Attempts to relate to such a system the bifurcation of a stipe or the proximal end of D. flabelliforme emphasised the very abnormal character of the currently-accepted interpretation, and the need for re-examination and either confirmation or revision. Such re-examination has led to a new interpretation of the structure, and D. flabelliforme is now considered to exhibit normal branching division into two stolothecae and an autotheca. Consequent modifications in interpretation of the proximal end both of D. flabelliforme and one of its descendants (Addograptus) are considered.