[Kingdom] Animalia Linnaeus, 1758 - animals
   Grade Enterozoa
     Grade Cœlomata
       Phylum Echinoderma
         Branch Ambulacrata
           Class Asteroidea Blainville, 1830 - sea stars
             Grade Ophiuræ
               Order Ophiastra
                 1 Genus Ophiura Lamarck, 1801
                 2 Genus Ophiothrix Müller & Troschel, 1840