A new monotypic genus, Turneroconcha, is established for T. magnifica (Boss Turner) which was originally assigned to the genus Calyptogena Dall. The distinguishing morphological characters of the new genus are the combination of both conchological and anatomical features including: the presence of only two tooth elements in the right valve; submerged location of the posterior part of the posterior lamellar ligament layer; the absence of a subumbonal pit, lunular incision, escutcheon and pallial sinus; the presence of both pairs of demibranchs; the tubular structure of marginal parts of the interlamellar septa in gills; an inner valve of the inhalant siphon without processes; tentaculate inner mantle fold 3 and a Z-shaped digestive tract. Analysis of morphological data on Recent and fossil pliocardiines shows that Turneroconcha gen. nov. can be presently considered as a monotypic genus. The comparative morphological analysis of the new genus with described pliocardiine genera is consistent with available molecular results. Turneroconcha gen. nov. is endemic to the East-Pacific Rise and Galapagos Rift and occurs at water depths of 2251 to 2791 m. It is the only pliocardiine genus known so far with a mainly epifaunal life habit. No fossils of Turneroconcha gen. nov. are known.
Keywords: Mollusca, chemosymbiotic bivalves, deep-sea, bathyal, morphology, anatomy, systematics, new combination.