Reconstruction of the problematic animal, Anomalocaris sp., from the Middle Cambrian Chengjiang fauna of China. Although similar in most respects to Anomalocaris canadensis from the Burgess Shale, the Chinese specimens show two long spines projecting from the tail. It is possible that the spines simply have not yet been recognized in the Burgess Shale specimens. Anomalocaris has experienced a long history of misinterpreted isolated parts. The front claws were originally described as shrimp, the circular mouth plate as a jellyfish, and the body as yet another animal until more complete specimens united the parts. Probably a fearsome predator, Anomalocaris was a half meter in length.