Phylum Mollusca Linnaeus, 1758 - molluscs
   Class Polyplacophora Blainville, 1816 [monotypic] - chitons
     Subclass Polyplacophora Gray, 1821 [monotypic] see Class Polyplacophora Blainville, 1816
       Order Lepidopleurida Thiele, 1910
         Suborder Chitonina Thiele, 1909
           Family Mopaliidae Dall, 1889
             Subfamily Mopaliinae Dall, 1889
               Genus Plaxiphora Gray, 1847
                 Subgenus Mercatora Leloup, 1942