[organisms] see Clade Biota Wagner 2004 [Wiemann, de Queiroz, Rowe, Planavsky, Anderson, Gogarten, Turner & Gauthier 2020]
   Phylum Echinodermata Bruguière, 1789 - echinoderms
     Class Echinoidea (Leske, 1778) - sea urchins and sand dollars
       01 Order Cidaroida Claus, 1880
       02 Order Echinothuroida see Order Echinothurioida Claus, 1880
       03 Order Diadematoida Duncan, 1889
       04 Order Pedinoida Mortensen, 1939
       05 Order Salenoida Delage & Herouard, 1903 see Order Salenioida Delage & Herouard, 1903
       06 Order Arbacioida Gregory, 1900
       07 Order Temnopleuroida (Mortensen, 1942)
       08 Order Echinoida Troschel, 1872
       09 Order Clypeasteroida A. Agassiz, 1872 - true sand dollars
       10 Order Cassiduloida Claus, 1880
       11 Order Pourtalesioida
       12 Order Spatangoida L. Agassiz, 1840