MACROSCENELLA (MOLLUSCA) FROM THE MIDDLE ORDOVICIAN OF WISCONSIN - A REINTERPRETATION AND REASSIGNMENT

Description of two new specimens of Macroscenella superba (Billings) provides additional data on this rare, poorly known Paleozoic genus. Macroscenella was considered first to be a gastropod, then a monoplacophoran, and finally a coelenterate. Chondrophorine affinities for this form cannot be totally ruled out, but the new specimens increase the probability that it is a mollusk. If so, Macroscenella is more likely a patellacean gastropod than a member of any other group of the Mollusca, though evidence for placement within the Mollusca is equivocal; the interior of the specimens is not exposed and musculature is unknown. If the integument was a shell, it was thin.