Nuculida should not be confused with Nuculanida.
Nuculida is an order of small saltwater clams, marine bivalve mollusks, within the subclass Protobranchia. "Nuculida" is sometimes spelled "Nuculoida". This order contains two families, the extant Nuculidae and the extinct Praenuculidae.[1] Clams in the family Nuculidae are commonly known as nut clams.