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 Nemertea Schultze, 1851 - ribbon worms
           Class Enopla Schultze, 1851
             Order Hoplonemertea Hubrecht, 1879
               Suborder Monostilifera Brinkmann, 1917
                 Family Tetrastemmatidae Hubrecht, 1879
                   Genus Tetrastemmaᵀ Ehrenberg, 1831
                     1 ?Tetrastemma esbenseni Wheeler, 1934
                     2 ?Tetrastemma gulliveri Bürger, 1893
                     3 Tetrastemma wilsoni Coe, 1943
                     4 Tetrastemma signifer Coe, 1904
                     5 Tetrastemma reticulatum Coe, 1904
                     6 Tetrastemma candidum (Müller, 1774)