life see Clade Biota Wagner 2004 [Wiemann, de Queiroz, Rowe, Planavsky, Anderson, Gogarten, Turner & Gauthier 2020]
   Empire Eukaryota (Chatton, 1925) see Domain Eukaryota Chatton, 1925
     Kingdom Animalia Linnaeus, 1758 - animals
       Subkingdom Bilateria Hatschek, 1888 [paraphyletic?] - bilaterians
         Branch Protostomia Grobben, 1908 [paraphyletic?] - protostomes see Infrakingdom Protostomia Grobben, 1908
           Infrakingdom Chaetognathi (Leuckart, 1854) Cavalier-Smith, 1998 [monotypic] see Infrakingdom Ecdysozoa Aguinaldo, Turbeville, Linford, Rivera, Garey, Raff & Lake, 1997
             Phylum Chaetognatha Leuckart, 1854 - chaetognaths
               1 Genus Sagitta Quoy & Gaimard, 1827
               2 Genus Spadella Langerhans, 1880