living organisms see Clade Biota Wagner 2004 [Wiemann, de Queiroz, Rowe, Planavsky, Anderson, Gogarten, Turner & Gauthier 2020]
   Superkingdom Eukaryotae see Domain Eukaryota Chatton, 1925
     Kingdom Animalia Linnaeus, 1758 - animals
       Subkingdom Protozoa Goldfuss, 1818 see Kingdom Protozoa Goldfuss, 1818
         Phylum Ciliophora Doflein, 1901 - ciliates
           Class Oligohymenophora see Class Oligohymenophorea de Puytorac et al., 1974
             Subclass Peritricha Stein, 1859 - peritrichs see Subclass Peritrichia Stein, 1859
               Order Peritrichida Stein, 1859 see Subclass Peritrichia Stein, 1859
                 Suborder Sessilina Kahl, 1933 see Order Sessilida Kahl, 1933
                   Family Ophrydiidae Ehrenberg, 1838
                     Genus Ophrydium Bory de St. Vincent, 1827
                       Ophrydium versatile (O.F. Müller, 1786) Bory, 1824