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 Nemata Cobb, 1919 see Phylum Nematoda Gegenbaur, 1859
           Class Adenophorea
             Subclass Enoplia Pearse, 1942
               Order Mononchida Jairajpuri, 1969
                 Suborder Mononchina Kirjanova & Krall, 1969
                   Superfamily Mononchoidea Filipjev, 1934
                     Family Iotonchusidae Jairajpuri, 1978 see Family Iotonchidae Jairajpuri, 1969
                       1 Genus Iotonchus Cobb, 1916
                       2 Genus Hadronchus Mulvey & Jensen, 1967
                       3 Genus Prionchulellus Mulvey & Jensen, 1967