Bite force estimates in juvenile based on simulated puncture marks.

Background: Bite marks attributed to adult have been subject to numerous studies. However, few bite marks attributed to have been traced to juveniles, leaving considerable gaps in understanding ontogenetic changes in bite mechanics and force, and the paleoecological role of juvenile tyrannosaurs in the late Cretaceous.

Methods: Here we present bite force estimates for a juvenile based on mechanical tests designed to replicate bite marks previously attributed to a of approximately 13 years old. A maxillary tooth of the juvenile specimen BMR P2002.4.1 was digitized, replicated in dental grade cobalt chromium alloy, and mounted to an electromechanical testing system. The tooth was then pressed into bovine long bones in various locations with differing cortical bone thicknesses at varying speeds for a total of 17 trials. Forces required to replicate punctures were recorded and puncture dimensions were measured.

Results: Our experimentally derived linear models suggest bite forces up to 5,641.19 N from cortical bone thickness estimated from puncture marks on an and a juvenile . These findings are slightly higher than previously estimated bite forces for a juvenile of approximately the same size as BMR P2002.4.1 but fall within the expected range when compared to estimates of adult .

Discussion: The results of this study offer further insight into the role of juvenile tyrannosaurs in late Cretaceous ecosystems. Furthermore, we discuss the implications for feeding mechanisms, feeding behaviors, and ontogenetic niche partitioning.