Meeting Abstract

P1.110  Saturday, Jan. 4 15:30  A Three-Dimensional Model of Bite Force in Alligator mississippiensis. SELLERS, K.C.*; MILLER-PHILLIPS, C.M.; SCHMIEGELOW, A.B.; DAVIS, J.L.; HOLLIDAY, C.M.; Univ. of Missouri; Xavier Univ.; Univ. of Missouri; Univ. of Massachusetts Amherst; Univ. of Missouri kcsty5@mail.missouri.edu

Bite force is an important character in analyses of the ecology of an organism. Higher bite forces allow organisms to process more resistant food items, giving them access to a wider variety of foods and niches. Although researchers can experimentally measure bite forces of living animals, the bite forces of extinct ones must be estimated. Despite a variety of different methods available for estimating bite forces, few models are validated with in vivo data. Validated modeling methods are particularly important for investigations of bite force and feeding function in fossil taxa as a means of increasing inferential accuracy. Here we test the accuracy of modeled bite forces of an ontogenetic series of American alligators (Alligator mississippiensis). Jaw muscles were digitally mapped using Strand7 software, and muscle resultants and bite forces were calculated using the Boneload program. Using areas of muscle attachment, muscle length, and modeled physiological parameters, we calculated the force exerted by each individual muscle, then used geometric relationships to sum each muscle force to yield total bite force at particular bite points. We then compared our calculated bite force values to measured values from animals of comparable sizes reported in the literature. Modeled bite forces were found to underestimate in vivo recordings from individuals of similar sizes. Likely reasons for this underestimation include anatomical details lost in the modeling process and current challenges with accurately wrapping muscles around bones. Increasingly accurate modeling techniques will enrich investigations into the role of bite force in ecology.