Gut contents and feeding in the Cambrian arthropodNaraoia

Element and diffraction analyses show that the gut contents in the Lower Cambrian arthropod Naraoia from Chengjiang, China, consist of genuine sediment. Such content in the gut is consistent with deposit-feeding in various marine worm groups. Deposit-feeding was probably the basic method of feeding in species of Naraoia, but it does not rule out occasional scavenging and even occasional capture of small prey. Less developed intestinal diverticula in N. longicaudata indicate that this species scanned the substrate surface for more nutritious food.