Pyramidellidae (Gastropoda: Heterobranchia) from the End of the World

Abstract

Current knowledge on the pyramidellids from the southern tip of South America appears restricted to a couple of species described in the beginning of the 20thcentury and a few taxa subsequently reported from this area, including some species recognized as new, but never formally described. This study fills this gap in the knowledge by performing the first revision on the diversity of Pyramidellidae occurring in the Magellanic Province. The material for this study arises from extant collections made along the Atlantic and Pacific coasts of Patagonia, the Beagle Channel, the Magellan Strait and in Burdwood Bank; this information was supplied with specimens from museum collections. As part of this study, eight pyramidellid species, belonging to the genera Turbonilla, Fargoa, Menestho and Brachystomia are recognized from the Magellanic Province, including five species new to science: Turbonilla deseadensis n. sp., Menestho beaglensis n. sp., M. patagonica n. sp., Brachystomia conica n. sp. and B. tenuilirata n. sp. The distinctive characters of Menestho, a genus frequently misunderstood in the past, are also discussed. The presence of Menestho and Brachystomia are here documented for the first time for the southern tip of South America. In addition, a neotype for Turbonilla strebeliStrebel, 1905 (nonVerrill, 1880) is here designated.