title: Dietary adaptions in the ultrastructure of dinosaur dentine.
abstract: Teeth are key to understanding the feeding ecology of both extant and extinct vertebrates. Recent studies have highlighted the previously unrecognized complexity of dinosaur dentitions and how specific tooth tissues and tooth shapes differ between taxa with different diets. However, it is unknown how the ultrastructure of these tooth tissues contributes to the differences in feeding style between taxa. In this study, we use third harmonic generation microscopy and scanning electron microscopy to examine the ultrastructure of the dentine in herbivorous and carnivorous dinosaurs to understand how the structure of this tissue contributes to the overall utility of the tooth. Morphometric analyses of dentinal tubule diameter, density and branching rates reveal a strong signal for dietary preferences, with herbivorous saurischian and ornithischian dinosaurs consistently having higher dentinal tubule density than their carnivorous relatives. We hypothesize that this relates to the hardness of the dentine, where herbivorous taxa have dentine that is more resistant to breakage and wear at the dentine-enamel junction than carnivorous taxa. This study advocates the detailed study of dentine and the use of advanced microscopy techniques to understand the evolution of dentition and feeding ecology in extinct vertebrates.
authors.affiliation: Department of Biology, University of Toronto Mississauga, Mississauga, Ontario, Canada L5 L 1C6 brinkkir@dentistry.ubc.ca.
authors.forename: Kirstin S
authors.identifier: 0000-0001-6630-1525
authors.initials: KS
authors.lastname: Brink
authors.affiliation: Molecular Imaging Center, National Taiwan University, Taipei 10617, Taiwan, Republic of China.
authors.forename: Yu-Cheng
authors.initials: YC
authors.lastname: Chen
authors.affiliation: Institute of Oral Medicine, National Cheng Kung University, 1 University Road, Tainan 701, Taiwan, Republic of China.
authors.forename: Ya-Na
authors.initials: YN
authors.lastname: Wu
authors.affiliation: Department of Electrical Engineering and Graduate Institute of Photonics and Optoelectronics, National Taiwan University, Taipei 10617, Taiwan, Republic of China.
authors.forename: Wei-Min
authors.initials: WM
authors.lastname: Liu
authors.affiliation: Institute of Oral Medicine, National Cheng Kung University, 1 University Road, Tainan 701, Taiwan, Republic of China.
authors.forename: Dar-Bin
authors.initials: DB
authors.lastname: Shieh
authors.affiliation: Dinosaur Evolution Research Center, Jilin University, Changchun, Jilin Province 130012, People's Republic of China.|National Chung Hsing University, Taichung 402, Taiwan, Republic of China.
authors.forename: Timothy D
authors.initials: TD
authors.lastname: Huang
authors.affiliation: Molecular Imaging Center, National Taiwan University, Taipei 10617, Taiwan, Republic of China.|Department of Electrical Engineering and Graduate Institute of Photonics and Optoelectronics, National Taiwan University, Taipei 10617, Taiwan, Republic of China.|Graduate Institute of Biomedical Electronics and Bioinformatics and Center for Optoelectronic Medicine, National Taiwan University, Taipei 10617, Taiwan, Republic of China.|Institute of Physics and Research Center for Applied Sciences, Academia Sinica, Taipei 115, Taiwan, Republic of China.
authors.forename: Chi-Kuang
authors.initials: CK
authors.lastname: Sun
authors.affiliation: Department of Biology, University of Toronto Mississauga, Mississauga, Ontario, Canada L5 L 1C6.|Dinosaur Evolution Research Center, Jilin University, Changchun, Jilin Province 130012, People's Republic of China.|National Chung Hsing University, Taichung 402, Taiwan, Republic of China.|Department of Optics and Photonics, National Central University, Jhongli, Taoyuan 32001, Taiwan, Republic of China.
authors.forename: Robert R
authors.initials: RR
authors.lastname: Reisz
mesh_terms: D000818:Animals; D060435:Carnivory / Q000502:physiology*; D003804:Dentin / Q000502:physiology* / Q000648:ultrastructure*; D025061:Dinosaurs / Q000033:anatomy & histology* / Q000502:physiology*
keywords: dentine tubule; morphometrics; multiple harmonics; scanning electron microscopy; third harmonic generation microscopy; tooth