Orthrozanclus (from Greek ὄρθρος + ζᾰ́γκλος (órthros + zánklos), "dawn scythe") is a genus of sea creatures known from two species, O. reburrus from the Middle Cambrian (~505 million years ago) Burgess shale and O. elongata from Early Cambrian (~518 million years ago) Maotianshan Shales. Animals in this genus were one to two centimeters long, with spikes protruding from their armored bodies. The placement of this genus into a specific family is not universally accepted.