[Kingdom] Animalia Linnaeus, 1758 - animals
   Grade Enterozoa
     Grade Cœlomata
       Phylum Mollusca Linnaeus, 1758 - molluscs
         Branch Lipocephala
           Class Spirobranchia
             Order Ecardines Bronn, 1862
               1 Genus Discina Lamarck, 1819
               2 Genus Lingula Bruguière, 1797