Phylum Mollusca Linnaeus, 1758 - molluscs
   Class Bivalvia Linnaeus, 1758 - bivalves
     Subclass Pteriomorphia Beurlen, 1944 see Superorder Pteriomorphia Beurlen, 1944
       Order Ostreida Férussac, 1822
         Suborder Pectinina Gray, 1854 see Order Pectinida Gray, 1854
           Superfamily Pectinoidea Rafinesque, 1815
             Family Spondylidae Gray, 1826 [monotypic] - thorny oysters
               Genus Spondylus Linnaeus, 1758
                 1 Subgenus Eltopera Iredale, 1939