Matching Items (2)
Description
Modern primate diet is well-studied because of its considerable influence on multiple aspects of morphology, including the shape of the facial skeleton and teeth. It is well-established that differences in craniofacial form influence feeding abilities by altering the nature of bite force production. Tooth morphology, likewise, has been shown to vary with diet across primates, particularly in the details of occlusal form. It has also been suggested that tooth form (e.g., tooth root size and shape and crown size) reflects, in part, the demands of resisting the stresses generated during feeding. However, while they are central to our efforts to infer diet in past species, the relationships between bite force production, craniofacial morphology and tooth form are not well-established. The current study is separated into two parts. In Part I, the hypothesis that crown size and root surface area are adapted to resist masticatory stress is evaluated by testing whether these features show correlated variation along the tooth row in a taxonomically diverse sample of primates. To further explore the adaptive nature of this correlation, pair-wise comparisons between primates with mechanically resistant diets and closely-related species consuming less resistant foods are performed. If crown size and root surface area covary along the tooth row, past research suggests they may be related to bite force. To test this hypothesis, Part II examines the variation of these dental characteristics in comparison to theoretically-derived bite force patterns along the tooth row. Results suggest that patterns of maximum bite force magnitude along the tooth row are variable both within and between species, underscoring the importance of individual craniofacial variation on masticatory force production. Furthermore, it is suggested that some adaptations traditionally associated with high bite force production (i.e., facial orthognathy) may increase anterior biting force at the expense of posterior biting force. Taken together, results from the current study reveal that both tooth root and crown size vary in conjunction with the mechanical properties of diet and with bite force patterns along the tooth row in anthropoids.
ContributorsLucas, Lynn (Author) / Spencer, Mark (Thesis advisor) / Schwartz, Gary (Committee member) / Kimbel, William (Committee member) / Arizona State University (Publisher)
Created2012
Description
By studying organismal performance, one can gain insight regarding the evolutionary and developmental processes that shape the adult organism. Bite force is an important trait that can be linked to performance, and therefore survival, of the entire organism. In order for an animal to successfully feed upon its prey, the components of the jaw, such as the skeleton and attached muscles, must be strong enough to withstand the forces required for capturing and then processing (masticating) the prey. Because sharks and skates have a fully cartilaginous skeleton, they theoretically bite off more than deemed biologically possible, these organisms, therefore, are excellent models for study when trying to understand bite performance. The goal was to measure the bite force of Leucoraja erinacea. Dissections were completed for 14 individuals, in order to expose the muscles beneath the skin. The muscles were then removed, and the mass was recorded. Calculations derived from the literature were used to determine total bite force. Linear regression was used to determine the relationship between bite force and size of the organism. The average maximum bite force of Leucoraja erinacea was determined to be roughly 23.3 Newtons (N). There was a positive relationship between bite force and size. This skate produces a much smaller bite force than many other organisms, providing insight into its ecological role in food webs. Many of the shells of commercially important prey were also much stronger than the bite forces estimated for these skates, suggesting that either the skates were not mature or large enough to feed on these prey, or, perhaps this species is unable to feed on these organisms entirely.
ContributorsBurke, Samantha Elaine (Author) / Ferry, Lara (Thesis director) / Wagner, Carl (Committee member) / School for the Science of Health Care Delivery (Contributor) / Barrett, The Honors College (Contributor)
Created2018-05