UNIONIDA STOLICZKA, 1871

Skawina, Aleksandra & Dzik, Jerzy, 2011, Umbonal musculature and relationships of the Late Triassic filibranch unionoid bivalves, Zoological Journal of the Linnean Society 163 (3), pp. 863-883 : 874

ORDER UNIONIDA STOLICZKA, 1871

Emended diagnosis: Freshwater bivalves characterized by linearly arranged pedal elevator attachments in the beak region, but having plesiomorphic nacreous internal shell layer, and, in underived forms, transversely ribbed cardinal teeth of the hinge.

Nomenclatorial remark: We prefer Unionida , rather than Unionoida or Unioniformes ( Bogan & Roe, 2008), because the ending -ida, not -oida, is generally applied to the genus-derived roots of ordinal-rank names in other molluscan classes and many animal phyla, but the vernacular name ‘unionoids’ is here applied to members of the order to allow a distinction from the family rank taxon Unionidae .