Digestive system and feeding mode in Cambrian naraoiid arthropods
Version of Record online: 2 JAN 2007
Volume 35, Issue 2, pages 107–120, June 2002
How to Cite
VANNIER, J. and CHEN, J.-Y. (2002), Digestive system and feeding mode in Cambrian naraoiid arthropods. Lethaia, 35: 107–120. doi: 10.1111/j.1502-3931.2002.tb00072.x
- Issue online: 2 JAN 2007
- Version of Record online: 2 JAN 2007
- received 5th June 2001, revised 6th December 2001.
The function of the digestive system of naraoiid arthropods is interpreted in the light of new observations on Early Cambrian specimens from China and detailed comparisons with Recent crustaceans and other arthropods. In naraoiids, paired tubular diverticulae ending as blind caeca are present along the entire midgut, and are interpreted as sites for the secretion of digestive enzymes. Naraoia bears one pair of long, ramifying, distensible diverticulae, possibly used for both food storage and digestion as suggested by Recent analogues (e.g. branchiuran and isopod crustaceans and limulids). Naraoiids were probably epibenthic scavengers/predators rather than mud-eaters. They were either opportunistic intermittent feeders (Naraoia) or more regular feeders (Misszhouia). The mud-fills of the alimentary canals are likely to be artefacts due to taphonomic and weathering processes or, less likely, to sediment ingestion by animals trapped alive in turbiditic flows. The case study of naraoiid arthropods adds to other fossil evidence supporting the idea that predation played a key role in the Early Cambrian food-webs and that organs adapted for this purpose had already reached a high level of diversity and anatomical sophistication.