Duplapex is an extinct genus of bivalved arthropod known from the Cambrian Stage 3 aged Qingjiang biota of Hubei, China, with a single species.

It is thought to be a close relative of Tuzoia, but unlike it, the reticulated (net patterned) bivalved carapace was interpreted to have opened at a wide angle.

The carapace had a pair of spines projecting posteriorly.

[1] In its original description, it was suggested to have eyes on annulated stalks, but later research suggested that these may have been preservational artifacts instead.

This prehistoric arthropod–related article is a stub.