Hoplocarida is a subclass of crustaceans. The only extant members are the mantis shrimp, but two other orders existed in the Palaeozoic: Aeschronectida and Palaeostomatopoda.

The clade Multicrustacea constitutes the largest superclass of crustaceans, containing approximately four-fifths of all described non-hexapod crustacean species, including crabs, lobsters, crayfish, s