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 Eumetazoa Butschli, 1910 see [unranked] Eumetazoa Bütschli, 1910
         Phylum Platyhelminthes Gegenbaur, 1859 - flatworms
           Class Trematoda Rudolphi, 1808 - flukes see Infraclass Trematoda Rudolphi, 1808
             Subclass Digenea Carus, 1863
               Order Plagiorchiida La Rue, 1957
                 Suborder Plagiorchiata
                   Superfamily Microphalloidea Ward, 1901
                     Family Eumegacetidae Travassos, 1922
                       1 Genus Eumegacetes Looss, 1900
                       2 Genus Papillatrema Oshmarin, 1964
                       3 Genus Posthovitellum Skrjabin, 1966