Stronger evidence that Anomalocaris ate trilobites comes from fossilised faecal pellets, which contain trilobite parts and are so large that the anomalocarids are the only known organism from that period large enough to have produced them.[16] However, since Anomalocaris lacks any mineralised tissue, it seemed unlikely that it would be able to penetrate the hard, calcified shell of trilobites.[16] Rather, the coprolites may have been produced by a different organism, such as a trilobite.[19]