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 Chitonidae Rafinesque, 1815
             Subfamily Toniciinae Pilsbry, 1893
               1 Genus Tonicia Gray, 1847
               2 Genus Onithochiton Gray, 1847