New species of Thyasiridae (Bivalvia) from chemosynthetic communities in the Atlantic Ocean

A new genus and two new species of Thyasiridae are described from deep-water chemosynthetic communities in the Atlantic Ocean. Spinaxinus sentosus n. gen., n. sp. is distinguished by both shell shape and periostracal characters and bears little resemblance to other known thyasirids. It was collected from the organic cargo of the sunken ship, Francois Vieljeux and this remains the only record of this species. Thyasira southwardae n. sp. was collected from the Logatchev hydrothermal site and is morphologically similar to T. sarsi, T. oleophila and T. methanophila all known to be associated with chemosynthetic sites.