organisms see Clade Biota Wagner 2004 [Wiemann, de Queiroz, Rowe, Planavsky, Anderson, Gogarten, Turner & Gauthier 2020]
   Eukaryota Chatton, 1925 - eukaryotes see Domain Eukaryota Chatton, 1925
     Kingdom Animalia Linnaeus, 1758 - animals
       Protostomia Grobben, 1908 see Infrakingdom Protostomia Grobben, 1908
         Phylum Arthropoda Siebold, 1848 - arthropods
           01 Class Pycnogonida Latreille, 1810 - pycnogonids
           02 Class †Trilobita Walch, 1771 - trilobites
           03 Class Merostomata Dana, 1852 - horseshoe crabs see Class Xiphosura Latreille, 1802
           04 Class Arachnida Lamarck, 1801
           05 Class Remipedia Yager, 1981 - remipedes
           06 Class Ostracoda Latreille, 1802 - ostracods
           07 Class Cephalocarida H.L. Sanders, 1955 - cephalocarids
           08 Class Branchiopoda Latreille, 1817 - branchiopods
           09 Class Maxillopoda Dahl, 1956 see Subphylum Pancrustacea Zrzavý et al., 1997
           10 Class Cirripedia (Rafinesque, 1816) see Infraclass Cirripedia Burmeister, 1834
           11 Class Malacostraca Latreille, 1802
           12 Class Chilopoda Latreille, 1817 - centipedes
           13 Class Diplopoda Blainville, 1844 - millipedes
           14 Class Pauropoda Lubbock, 1868 - pauropodans
           15 Class Symphyla Ryder, 1880 - symphylans
           16 Class Insecta Linnaeus, 1758 - insects