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 Arthropoda Siebold, 1848 - arthropods
           Subphylum Crustacea Brünnich, 1772 - crustaceans see Superclass Crustacea Pennant, 1777
             Subclass Malacostraca Latreille, 1802 see Class Malacostraca Latreille, 1802
               Superorder Eucarida Calman, 1904
                 Order Decapoda Latreille, 1802 - decapods
                   Suborder Pleocyemata Burkenroad, 1963
                     Infraorder Astacidea Latreille, 1802 - crayfish and chelate lobsters
                       Superfamily Parastacoidea Huxley, 1879 see Superfamily Astacoidea Latreille, 1802
                         Family Parastacidae Huxley, 1879
                           Genus Euastacus Clark, 1936
                             Euastacus serratus (Shaw, 1794), nom. illeg. see Euastacus spinifer (Heller, 1865)