Genus Gigantidas Cosel & Marshall, 2003

Type species. Gigantidas gladius Cosel & Marshall, 2003 .

Remarks. This genus was erected by Cosel & Marshall (2003) to include only the type species, with a second species, G. horikoshii Hashimoto & Yamane, 2005, added shortly afterwards from vent sites off Japan . A molecular analysis of bathymodioline mussels by Thubaut et al. (2013) moved the “ Bathymodiolus ” childressi clade into Gigantidas Cosel & Marshall, 2003, substantially increasing the number of extant species ascribed to this genus. Gigantidas coseli Saether, Little, Campbell, Marshall, Collins & Alfaro, 2010, from the Miocene of New Zealand, remains its only fossil species.