Taxonomy of Antarctic Buccinoidea (Gastropoda: Neogastropoda) revisited based on molecular data

Abstract

The superfamily Buccinoidea is the most speciose group of Neogastropoda within the Antarctic Convergence, with ~70 species classified in 21 genera, but is still poorly represented in molecular phylogenies. The first molecular data on the group presented in the recent phylogeny of the Buccinoidea (Kantor et al. 2022) lacked many important lineages, thereby limiting inference of the relationships of Antarctic Buccinoidea. We revisited relationships of the Antarctic Buccinoidea, involving recently collected molecular-grade samples from the bathyal and abyssal depths of the Scotia Sea, the Weddel Sea and adjacent regions. Our data set includes 25 species (including six genera studied on a molecular basis for the first time), sequenced for five phylogenetic markers: the barcode fragment of cox1 gene, fragments of ribosomal 12S, 16S rRNA and 28S and nuclear H3 genes. Based on phylogenetic reconstructions, we synonymise the genus Lussitromina with Falsitromina and reassign the latter from Cominellidae to Prosiphonidae. We confirm the placement of four further genera, Drepanodontus, Germonea, Parabuccinum and Spikebuccinum in Prosiphonidae. We detect a previously unrecognised deep lineage of the family Prosiphonidae and describe this as the new genus Scotiabuccinum. The genus Parabuccinum, previously recorded in the Magellanic province and off the eastern coast of Argentina was reported for the first time within the Antarctic Convergence. We discover four previously unrecognised species of Antarctic Prosiphonidae and these are the first Buccinoidea from Antarctic waters described based on molecular data. According to our data, all but two species of Antarctic Buccinoidea belong to the family Prosiphonidae. Seven of the nineteen Recent Antarctic Prosiphonidae genera (36%) cross the boundaries of the Convergence and eight Antarctic genera are monotypic (42%). Currently no Buccinoidea species are known to occur both within and outside the Antarctic Convergence. ZooBank: urn:lsid:zoobank.org:pub:DEEA1599-C951-414E-9098-563EAD10BD57