Anomalocaridid

Anomalocaridids are a group of very early marine animals known primarily from fossils found in Cambrian deposits in China, USA, Canada, Poland and Australia. They were long thought to be restricted to this range, but the discovery of large Ordovician specimens extended this somewhat. The later Devonian Schinderhannes, a great appendage arthropod that retains many anomalocaridid features, extended their record by some hundred million years — their non-mineralised nature means they are absent from the intermediate fossil record. Anomalocarids are the largest Cambrian animals known — some Chinese forms may have reached 2 m (7 ft) in length — and most of them were probably active carnivores.