[organisms] see Clade Biota Wagner 2004 [Wiemann, de Queiroz, Rowe, Planavsky, Anderson, Gogarten, Turner & Gauthier 2020]
   Phylum Mollusca Linnaeus, 1758 - molluscs
     Class Gastropoda Cuvier, 1795 - snails and slugs
       Family Littorinidae Children, 1834 - periwinkles
         Genus Littorina Férussac, 1822
           Littorina arcana Hannaford-Ellis, 1978