Biomechanical bite simulation in Eucyon davisi (Mammalia, Canidae) and comparison with extant Canids.

Despite their ecological impact as predators, several aspects concerning canid palaeoecology remain poorly investigated. This is curious because their evolutionary history displays an intriguing variability in feeding-related adaptations, representing an attractive research topic. To explore this topic, we digitally simulated the bite of the medium-sized fossil canid Eucyon davisi (Late Miocene-Early Pliocene) using Finite Element Analysis (FEA). The aim of this study is the improvement of our knowledge on the feeding ecology of this basal Canini through the comparison of its reaction stress and bite efficiency with those obtained from a sample of extant Canidae. The cranial models were acquired through CT-scan, and the FE simulation was built using a series of trusses to reconstruct the muscles. We simulated a bilateral canine bite, a unilateral carnassial bite, and a unilateral bite at the M1. The stress patterns and the estimated bite forces across the three simulated load cases suggest for E. davisi a generalist ecology recalling the living jackal-like forms of the genus Lupulella. Likely its dietary range covered small vertebrates and non-meat food. Moreover, the FEA results highlight a role of the frontal sinuses in the mechanical behaviour of the cranium during a biting action.