Kingdom [Animalia] Linnaeus, 1758 - animals
   Subkingdom Metazoa Haeckel, 1874 see Kingdom Animalia Linnaeus, 1758
     Division Eumetazoa Butschli, 1910 see Subkingdom Eumetazoa Butschli, 1910
       Subdivision Bilateralia
         Phylum Echinodermata Bruguière, 1789 - echinoderms
           Class Echinoidea (Leske, 1778) - sea urchins and sand dollars
             Subclass Euechinoidea Bronn, 1860
               Superorder Atelostomata von Zittel, 1879 - irregular urchins
                 1 Order Cassiduloida Claus, 1880
                 2 Order Holasteroida Durham & Melville, 1957 see Suborder Holasterina
                 3 Order Spatangoida L. Agassiz, 1840