title: The role of ammonites in the Mesozoic marine food web revealed by jaw preservation.
abstract: Ammonites are prominent in macroevolutionary studies because of their abundance and diversity in the fossil record, but their paleobiology and position in the marine food web are not well understood due to the lack of preserved soft tissue. We present three-dimensional reconstructions of the buccal apparatus in the Mesozoic ammonite Baculites with the use of synchrotron x-ray microtomography. Buccal mass morphology, combined with the coexistence of food remains found in the buccal mass, suggests that these ammonites fed on plankton. This diet may have extended to all aptychophoran ammonites, which share the same buccal mass morphology. Understanding the role of these ammonites in the Mesozoic food web provides insights into their radiation in the Early Jurassic, as well as their extinction at the end of the Cretaceous/early Paleogene.
authors.affiliation: UMR-CNRS 7207, Département Histoire de la Terre, Muséum National d'Histoire Naturelle, 47 rue Cuvier, 75231 Paris Cedex 05, France. kruta@mnhn.fr
authors.forename: Isabelle
authors.initials: I
authors.lastname: Kruta
authors.forename: Neil
authors.initials: N
authors.lastname: Landman
authors.forename: Isabelle
authors.initials: I
authors.lastname: Rouget
authors.forename: Fabrizio
authors.initials: F
authors.lastname: Cecca
authors.forename: Paul
authors.initials: P
authors.lastname: Tafforeau
mesh_terms: D000818:Animals; D005075:Biological Evolution; D049830:Cephalopoda / Q000033:anatomy & histology* / Q000502:physiology; D004032:Diet; D004064:Digestive System; D053476:Extinction, Biological; D005247:Feeding Behavior; D020387:Food Chain; D005580:Fossils; D049851:Gastropoda / Q000033:anatomy & histology; D033321:Isopoda / Q000033:anatomy & histology; D007568:Jaw / Q000033:anatomy & histology; D014070:Tooth / Q000033:anatomy & histology; D055114:X-Ray Microtomography; D015048:Zooplankton