[Kingdom] Animalia Linnaeus, 1758 - animals
   Grade Plastidozoa [monotypic]
     [Phylum] Protozoa (Goldfuss, 1818) C.T. von Siebold, 1854 see Kingdom Protozoa Goldfuss, 1818
       Grade Stomatodea
         Class Suctoria [monotypic]
           Order Suctoria
             Genus Ophryodendron Claparède & Lachmann, 1859