[organisms] see Clade Biota Wagner 2004 [Wiemann, de Queiroz, Rowe, Planavsky, Anderson, Gogarten, Turner & Gauthier 2020]
   Eukaryota Chatton, 1925 - eukaryotes see Domain Eukaryota Chatton, 1925
     Supergroup Chromalveolata Adl et al., 2005 - chromalveolates see Kingdom Chromista Caval.-Sm. (1981)
       Stramenopiles Patterson, 1990 - stramenopiles see Superphylum Heterokonta Caval.-Sm. (1986)
         Opalinata Wenyon, 1926 see Superclass Opalinata Wenyon, 1926
           Opalinea Wenyon, 1926 see Class Opalinea Wenyon (1926)
             1 Genus Cepedea Metcalf, 1920
             2 Genus Opalina Purkinje & Valentin, 1835
             3 Genus Protoopalina Metcalf, 1918
             4 Genus Protozelleriella Delvinquier, Markus & Passmore, 1991
             5 Genus Zelleriella Metcalf, 1920, nom. nud.