Class Bivalvia Linnaeus, 1758 - bivalves
   Subclass Autobranchia Grobben, 1894
     Superorder Heteroconchia Gray, 1854
       Clade Heterodonta Neumayr, 1884
         Order Venerida Gray, 1854
           Superfamily Mactroidea Lamarck, 1809
             Family Mactridae Lamarck, 1809 - surf clams
               Subfamily Kymatoxinae Stenzel & Krause, 1957