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 Polystilifera Brinkmann, 1917
                 Tribe Pelagica Brinkmann, 1917
                   Subtribe Eupelagica
                     Family Planktonemertidae Brinkmann, 1917
                       1 Genus Planktonemertes Woodworth, 1899
                       2 Genus Crassonemertes Brinkmann, 1917
                       3 Genus Mononemertes Coe, 1926
                       4 Genus Neuronemertes Coe, 1926
                       5 Genus Plenanemertes Coe, 1954
                       6 Genus Tononemertes Coe, 1954
                       7 Genus Mergonemertes Brinkmann, 1917