Phylum Mollusca Linnaeus, 1758 - molluscs
   Class Bivalvia Linnaeus, 1758 - bivalves
     Subclass Protobranchia Pelseneer, 1889
       Order Nuculida Dall, 1889
         Superfamily Nuculanoidea Adams & Adams, 1858 (1854)
           Family Yoldiidae Dall, 1908
             Subfamily Yoldiinae Dall, 1908
               Genus Yoldia Møller, 1842
                 Subgenus Aequiyoldia Soot-Ryen, 1951