organisms see Clade Biota Wagner 2004 [Wiemann, de Queiroz, Rowe, Planavsky, Anderson, Gogarten, Turner & Gauthier 2020]
   Kingdom Animalia Linnaeus, 1758 - animals
     Eumetazoa Bütschli, 1910 - eumetazoans
       Bilateria Hatschek, 1888 - bilaterians see Subkingdom Bilateria Hatschek, 1888
         Protostomia Grobben, 1908 see Infrakingdom Protostomia Grobben, 1908
           Spiralia Schleip, 1929 - spiralians see Superphylum Spiralia Schleip, 1929
             Teloblastica (C. Nielsen, 1995) see [unranked] Protostomia Grobben, 1908
               Articulata Cuvier see [unranked] Protostomia Grobben, 1908
                 Euarticulata see [unranked] Protostomia Grobben, 1908
                   Phylum Annelida Lamarck, 1809 - segmented worms
                     "Polychaeta" see Class Polychaeta Grube, 1850
                       Class Echiura
                         Genus Echiurus Guérin-Ménéville, 1831
                         Genus Thalassema
                         Genus Urechis Seitz, 1907