Polycopidae

Polycopidae is a family of marine ostracods. Its members are related to animals in the suborder Halocypridina, but are sufficiently distinct to be placed in the sub-order Cladocopina. There is even some speculation that a separate order may be warranted. The genera in the family differ from the other suborder, Halocypridina, in several features: the central adductor muscle scars are in a triangular (3 scars) or half-rosette (15 scars) pattern, they lack sixth and seventh limbs, and the maxilla (=fourth limb) has both an exopod and endopod (the maxilla in the Halocypridina lacks an exopod).