New taxonomic position and neotype designation for the conoidean gastropod Pleurotoma patagonica d’Orbigny, 1841

Abstract

Pleurotoma patagonica d’Orbigny, 1841 has been placed in several genera and families since its original description, perhaps because the type material, presumed lost, was never revised after the original description and because of the chaotic systematics of conoidean gastropods. New specimens, matching the original description and illustration and collected near the type locality allowed us to study the radula, shell, and protoconch. A neotype designation is proposed for this species in order to fix its identity. We tentatively assign it to the mangeliid genus Bela Leach, 1847, thus establishing Bela pata-gonica (d’Orbigny, 1841) comb. nov. Eleven species of Bela have been reported from Argentine waters; however, all of them have been reclassified into other genera and even other families. Despite the appar-ent geographic distance of B. patagonica comb. nov. from other species of this genus, this taxonomic placement of this species seems most appropriate and emphasizes shell characters until molecular data become available.