title: The oral cone of Anomalocaris is not a classic ''peytoia''.
abstract: The Cambro-Ordovician anomalocaridids are large ecdysozoans commonly regarded as ancestors of the arthropods and apex predators. Predation is indicated partly by the presence of an unusual "peytoia"-type oral cone, which is a tetraradial outer ring of 32 plates, four of which are enlarged and in perpendicular arrangement. This oral cone morphology was considered a highly consistent and defining characteristic of well-known Burgess Shale taxa. It is here shown that Anomalocaris has a different oral cone, with only three large plates and a variable number of smaller and medium plates. Its functional morphology suggests that suction, rather than biting, was used for food ingestion, and that anomalocaridids in general employed a range of different scavenging and predatory feeding strategies. Removing anomalocaridids from the position of highly specialized trilobite predators forces a reconsideration of the ecological structure of the earliest marine animal communities in the Cambrian.
authors.affiliation: Department of Palaeontology, Natural History Museum, Cromwell Road, London, SW7 5BD, UK. A.Daley@nhm.ac.uk
authors.forename: Allison C
authors.initials: AC
authors.lastname: Daley
authors.forename: Jan
authors.initials: J
authors.lastname: Bergström
mesh_terms: D000818:Animals; D001181:Arthropods / Q000033:anatomy & histology*; D005580:Fossils; D009055:Mouth / Q000033:anatomy & histology