title: Synchrotron-aided reconstruction of the conodont feeding apparatus and implications for the mouth of the first vertebrates.
abstract: The origin of jaws remains largely an enigma that is best addressed by studying fossil and living jawless vertebrates. Conodonts were eel-shaped jawless animals, whose vertebrate affinity is still disputed. The geometrical analysis of exceptional three-dimensionally preserved clusters of oro-pharyngeal elements of the Early Triassic Novispathodus, imaged using propagation phase-contrast X-ray synchrotron microtomography, suggests the presence of a pulley-shaped lingual cartilage similar to that of extant cyclostomes within the feeding apparatus of euconodonts ("true" conodonts). This would lend strong support to their interpretation as vertebrates and demonstrates that the presence of such cartilage is a plesiomorphic condition of crown vertebrates.
authors.affiliation: Palaeontological Institute and Museum, University of Zurich, CH-8006 Zürich, Switzerland. goudemand@pim.uzh.ch
authors.forename: Nicolas
authors.initials: N
authors.lastname: Goudemand
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Orchard
authors.forename: Séverine
authors.initials: S
authors.lastname: Urdy
authors.forename: Hugo
authors.initials: H
authors.lastname: Bucher
authors.forename: Paul
authors.initials: P
authors.lastname: Tafforeau
mesh_terms: D000818:Animals; D005075:Biological Evolution; D002356:Cartilage; D005580:Fossils; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D007568:Jaw; D009055:Mouth; D017356:Synchrotrons; D014714:Vertebrates / Q000235:genetics*