No longer monotypic: new species of the buccinoidean genera Germonea and Drepanodontus in the southwestern Atlantic (Gastropoda: Buccinidae)

New species of the until now monotypic buccinoidean genera Germonea and Drepanodontus are described from the southwestern Atlantic waters. These genera are only otherwise known from lower bathyal and abyssal depths of Scotia Sea. Germonea costulosa n. sp. collected near Namuncura ' /Burdwood Bank in 681 to 785 m depth is the second known species of the genus characterized by distinctive regular ribs. In addition, Drepanodontus peonza n. sp., collected from the same area, is similar to the type species of this genus with two distinctive spiral cords along all whorls. The bathymetry of both new species is shallower than that of the already described species, at upper slope depths. Geographically the new species put both genera on both sides of the Antarctic convergence. Previous reports include D. tatyanae sharing this distribution rising some questions about the effectiveness of the Drake passage as a barrier.

Automated summary

Two new species from the southwestern Atlantic waters, belonging to previously monotypic buccinoidean genera, are described in this study. These new species have shallower bathymetry compared to the previously described species, and they put both genera on both sides of the Antarctic convergence geographically. This distribution raises questions about the effectiveness of the Drake passage as a barrier, as some species are found on both sides.