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 Echinodermata Bruguière, 1789 - echinoderms
           Subphylum Echinozoa von Zittel, 1895 see Infraphylum Echinozoa Haeckel, in Von Zittell, 1895
             Class Echinoidea (Leske, 1778) - sea urchins and sand dollars
               Subclass Euechinoidea Bronn, 1860
                 Superorder Atelostomata von Zittel, 1879 - irregular urchins
                   Order Spatangoida L. Agassiz, 1840
                     Suborder Amphisternata
                       01 Family Toxasteridae Lambert, 1920
                       02 Family Hemiasteridae H.L. Clark, 1917
                       03 Family Palaeostomatidae Lovén, 1868
                       04 Family Pericosmidae Lambert, 1905
                       05 Family Schizasteridae Lambert, 1905
                       06 Family Aeropsidae Lambert, 1896
                       07 Family Brissidae Gray, 1855
                       08 Family Spatangidae Gray, 1825
                       09 Family Loveniidae Lambert, 1905
                       10 Family Asterostomatidae Pictet, 1857