Meeting Abstract

P1.116  Saturday, Jan. 4 15:30  Estimating Bite Force in Fossil Vertebrates Using 3D Computational Methods HOLLIDAY, CM*; TEA, J; SELLERS , KC; WITMER, LM; DAVIS, JL; University of Missouri; University of Houston; University of Missouri; Ohio University ; University of Southern Indiana hollidayca@missouri.edu

Accurately predicting bite forces in extinct vertebrates remains a challenging yet important tool for ecologists, functional morphologists, and paleobiologists. Only recently have three-dimensional computational methods offered more informed methods for reconstructing the anatomy and cranial biomechanical environment compared to previous 2D methods. Despite being one of the most studied non-avian dinosaurs, estimates of bite force in Tyrannosaurus rex range orders of magnitude (5,000N-150,000N) suggesting more refined analyses are needed. Here we review previous estimates of bite force in the T. rex complemented with a new model. 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. A sensitivity analysis was employed to test the behavior of the model using different physiological cross sectional areas of muscles and bite points. Our model found bite forces of T. rex to range from 5,000N to 30,000N, which are forces substantially lower than most previous estimates but fall near estimates derived from dental data. This model and others like it indicate that anatomically-informed, 3D lever-based computational models are more accurate than many previous methods for estimating bite force and will be useful for testing functional and ecological hypotheses pertaining to the evolution of feeding in vertebrates.