Teeth vs. Claws: Reverse Engineering of an Early Cretaceous Predator

By combining modern numerical dynamic and structural analysis we were able to simulate the masticatory dynamics of an Early Cretaceous predator, Dienonychus antirrhopus as reconstructed from an actual fossil. Objective: The aim of this study was to correlate the calculation of the biting forces with structural analysis and to develop a new method for masticatory dynamics analysis that correlates the above two factors. Methods: The analysis comprised of two parts, first, a multi-body dynamic analysis was carried out to determine the structural loading conditions for a given range of biting forces. The second part, was a Finite Element Analysis (FEA) of the structure based on the previously determined loads, to assess the impact they have upon the skeletal structure. The biting force regime was gradually decreased, from one similar with the one of an extant carnivore, the lion (Panthera leo: 4200N) to a value that will provide skull loading within the structural “safety zone” of the system. Results: The results have shown that, the upper limit of the biting force the predator could develop is about 800N, and any value above this one will create compressive and tensile stresses beyond the material and design limits. Conclusions: Based on the results, it can be seen that the predator has a rather weak bite, hence its over-developed claw may have assumed an important role in prey capture. Also, the analysis method we are proposing proves to be a powerful and far more precise tool in paleo-biology, while it have a comprehensive three-dimensional approach of the calculation, combining naturally the dynamic function with the structural resistance.