[Kingdom] Animalia Linnaeus, 1758 - animals
   Grade Enterozoa
     Grade Cœlomata
       Phylum Vertebrata Lamarck, 1801 see Infraphylum Vertebrata Lamarck, 1801
         Branch Cephalochorda [monotypic]
           Class Leptocardia Müller
             Genus Amphioxus Yarrell, 1836 see Genus Branchiostoma Costa, 1834