Mandibular force profiles and tooth morphology in growth series of Albertosaurus sarcophagus and Gorgosaurus libratus (Tyrannosauridae: Albertosaurinae) provide evidence for an ontogenetic dietary shift in tyrannosaurids

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dc.contributor.authorTherrien, Francois
dc.contributor.authorZelenitsky, Darla Karen
dc.contributor.authorVoris, Jared Thomas
dc.contributor.authorTanaka, Kohei
dc.date.accessioned2023-10-10T15:51:14Z
dc.date.available2023-10-10T15:51:14Z
dc.date.issued2021-01-26
dc.description.abstractThe albertosaurines Albertosaurus sarcophagus and Gorgosaurus libratus are among the best represented tyrannosaurids, known from nearly complete growth series. These specimens provide an opportunity to study mandibular biomechanical properties and tooth morphology to infer changes in feeding behaviour and bite force through ontogeny in tyrannosaurids. Mandibular force profiles reveal that the symphyseal region of albertosaurines is consistently stronger in bending than the mid-dentary region, indicating that the anterior extremity of the jaws played an important role in prey capture and handling through ontogeny. The symphyseal region was better adapted to withstand torsional stresses than in most non-avian theropods, but not to the extent seen in Tyrannosaurus rex, suggesting that albertosaurine feeding behaviour may have involved less bone crushing or perhaps relatively smaller prey than in Tyrannosaurus rex. The constancy of these biomechanical properties at all known growth stages indicates that although albertosaurines maintained a similar feeding strategy through ontogeny, prey size/type had to change between juvenile and mature individuals. This ontogenetic dietary shift likely happened when individuals reached a mandibular length of ∼58 cm, a size at which teeth shift from ziphodont to incrassate in shape and bite force begins to increase exponentially. The fact that large albertosaurines were capable of generating bite forces equivalent to similar-sized tyrannosaurines suggests that no significant differences in jaw-closing musculature existed between the two clades and that the powerful bite of Tyrannosaurus rex is the result of its large body size rather than of unique adaptations related to a specialized ecology.
dc.description.grantingagencyNatural Sciences and Engineering Research Council (NSERC)
dc.identifier.citationTherrien, F., Zelenitsky, D. K., Voris, J. T., & Tanaka, K. (2021). Mandibular force profiles and tooth morphology in growth series of Albertosaurus sarcophagus and Gorgosaurus libratus (Tyrannosauridae: Albertosaurinae) provide evidence for an ontogenetic dietary shift in tyrannosaurids1. Canadian Journal of Earth Sciences, 58(9), 812–828. https://doi.org/10.1139/cjes-2020-0177
dc.identifier.doihttps://doi.org/10.1139/cjes-2020-0177
dc.identifier.grantnumberRGPIN/04854
dc.identifier.urihttps://hdl.handle.net/1880/117367
dc.identifier.urihttps://doi.org/10.11575/PRISM/42210
dc.language.isoenen
dc.publisherCanadian Journal of Earth Sciences (Canadian Science Publishing)
dc.publisher.facultyScienceen
dc.publisher.institutionUniversity of Calgaryen
dc.publisher.policyhttps://cdnsciencepub.com/about/policies/publishing-policy
dc.rightsUnless otherwise indicated, this material is protected by copyright and has been made available with authorization from the copyright owner. You may use this material in any way that is permitted by the Copyright Act or through licensing that has been assigned to the document. For uses that are not allowable under copyright legislation or licensing, you are required to seek permission.en
dc.titleMandibular force profiles and tooth morphology in growth series of Albertosaurus sarcophagus and Gorgosaurus libratus (Tyrannosauridae: Albertosaurinae) provide evidence for an ontogenetic dietary shift in tyrannosaurids
dc.typeArticle
ucalgary.scholar.levelFaculty, graduate, researcher
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