[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
       Order Echinoida Troschel, 1872
         Family Echinidae Gray, 1825
           1 Genus Echinus Linnaeus, 1758
           2 Genus Paracentrotus Mortensen, 1903
           3 Genus Psammechinus Agassiz, 1846