[Kingdom] Animalia Linnaeus, 1758 - animals
   Grade Enterozoa
     Grade Cœlomata
       Phylum Echinoderma
         Branch Ambulacrata
           Class Echinoidea (Leske, 1778) - sea urchins and sand dollars
             Grade Autechini
               Branch Petalosticha
                 Order Clypeastridæ
                   1 Genus Clypleaster Müller, 1854, nom. null. see Genus Clypeaster Lamarck, 1801
                   2 Genus Echinocyamus van Phelsum, 1774