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 Turbellaria Ehrenberg, 1831 - planarians see Subphylum Turbellaria Ehrenberg, 1831
             Order Catenulida Meixner, 1924 - catenulid flatworms
               Family Stenostomidae Vejdovsky, 1880
                 1 Genus Rhynchoscolex Leidy, 1851
                 2 Genus Myostenostomum Luther, 1960
                 3 Genus Stenostomum Schmidt, 1848