Systematics and palaeobiology of the crested hadrosaurine Saurolophus from Canada and Mongolia

  • Author / Creator
    Bell, Phil
  • Reappraisal of Saurolophus confirms Saurolophus osborni and Saurolophus angustirostris as distinct species. Synapomorphies of Saurolophus include a spike-like pseudonarial crest formed by the nasals, frontals, and prefrontals; tripartite frontals with anteroventral and posterodorsal extensions that buttress the underside of the nasals; posterodorsal process on the prefrontal that buttresses the posterolateral edge of the nasal crest; and the presence of at least one supraorbital element. Phylogenetic analysis supports the close relationship between Saurolophus, Prosaurolophus, and Kerberosaurus. Material from the Maastrichtian Moreno Formation, California, previously assigned to Saurolophus is poorly preserved and lacks important diagnostic elements. This taxon shares traits of both Saurolophus and Edmontosaurus; however, as no unambiguous synapomorphies could be identified, this material is conservatively reassigned to Hadrosaurinae indet. The integument of Saurolophus varies significantly along the length of the body in both species. For the first time in the Dinosauria, soft tissue anatomy can be used to differentiate between species of single genus. A new standardised scheme for scale descriptions is also proposed. A Saurolophus bonebed from Mongolia represents the only dinosaur bonebed that preserves skin impressions. Ontogenetic evidence from this site suggests Barsboldia sicinskii, the only other hadrosaurid from the Nemegt Formation, is a junior synonym of Saurolophus angustirostris. An Edmontosaurus bonebed from the Horseshoe Canyon Formation (Alberta) contains nine animals including at least one Albertosaurus. The assemblage was subject to exposure, trampling, and rampant scavenging over a relatively short period (<1 year?). Future directions for hadrosaurid research are discussed.

  • Subjects / Keywords
  • Graduation date
  • Type of Item
  • Degree
    Doctor of Philosophy
  • DOI
  • License
    This thesis is made available by the University of Alberta Libraries with permission of the copyright owner solely for non-commercial purposes. This thesis, or any portion thereof, may not otherwise be copied or reproduced without the written consent of the copyright owner, except to the extent permitted by Canadian copyright law.
  • Language
  • Institution
    University of Alberta
  • Degree level
  • Department
    • Department of Biological Sciences
  • Supervisor / co-supervisor and their department(s)
    • Currie, Philip (Biological Science)
  • Examining committee members and their departments
    • Caldwell, Michael (Biological Science)
    • Horner, John (Museum of the Rockies)
    • Brinkman, Don (Royal Tyrrell Museum)
    • Lemelin, Pierre (Division of Anatomy)
    • Gingras, Murray (Earth and Atmospheric Science)