Date of Award
Spring 2026
Degree Type
Thesis
Degree Name
Master of Science (MS)
Department
Biological Science
College
College of Science and Health
First Advisor
Kenshu Shimada
Abstract
Sharks (Elasmobranchii: Selachii) are a diverse vertebrate clade that occupy a variety of ecological niches, and exhibit teeth suited for cutting, grasping, or crushing prey. The functional importance of tooth morphology is commonly investigated, but thus far, its relation to jaw curvature has not yet been quantitatively examined despite its central role in shark feeding mechanics. In this study, I conducted a 3D landmark-based geometric morphometric analysis of upper and lower jaw curvatures across all nine extant orders of sharks. The aims were to examine their variation across taxonomic orders and tooth function, and to decipher their functional, behavioral, biomechanical, and evolutionary implications. My study demonstrates that jaws with grasping-type teeth are not associated with any specific jaw curvature. However, sharks with cutting-type teeth are found in bite- and ram-feeding sharks with a broad to gently curved jaw Crushing-type teeth are found in durophagous, suction-feeding species with a straight to gently curved jaw, that shows lateral flaring at its posterior end. My study also indicates that similar jaw curvature morphologies evolved convergently in multiple lineages, likely due to similar functional requirements, rather than shared ancestry.
Copyright
Copyright © 2026 Maya G. Mahoney
Creative Commons License
This work is licensed under a Creative Commons Attribution-NonCommercial-No Derivative Works 4.0 International License.
Recommended Citation
Mahoney, Maya G., "The relationship between tooth forms and jaw curvature in sharks (Elasmobranchii: Selachii) and its functional, behavioral, biomechanical, and evolutionary implications" (2026). Theses and Dissertations from DePaul University. 117.
https://via.library.depaul.edu/theses-dissertations/117