Biomechanical performance of the skull and feeding in Araripesuchus gomesii (Nothosuchia, Uruguaysuchidae)

DEGRANGE, F.J.; POL, D.

General Roca

Congreso; 11 Congreso de la Asociación Paleontológica Argentina; 2016

Asociación Paleontológica Argentina

Araripesuchus gomesii Price, 1959 is a small carnivore nothosuchian from the Lower Cretaceous of Brazil. In the present study, a finite element analysis (FEA) was performed on the skull and jaw of A. gomesii AMNH 24450 to assess the cranial performance during trophic item capture. FEA calculates the stress and deformation manifested in a digitally generated structure in response to the forces acting on it. The model of the skull and jaw was generated from micro-CT scans and the analysis was performed using published homogeneous bone properties for crocodiles (Young's modulus: 15GPa; Poisson ratio: 0.29; Bone density: 1772.6 kg/m3). Anteroposterior, dorsoventral and lateromedial forces were simulated applying an estimated 158 Newtons bite force in three positions at the maxilla and mandible, assuming an isognathous jaw closure. The occipital condyle was constrained in space. In all the bite positions, Araripesuchus´ cranium shows higher stress under lateral loadings than when a dorsoventral or a ?pullback? force is applied, especially when the bite force was applied at the level of the largest caniniform or posterior to it. In the lower jaw, the largest stress is recorded during dorsoventral loading conditions. Based on these results, prey handling based on catching the trophic item and tearing it apart through caudally directed movements of the head would not pose risk to the skull of A. gomesii. The glenoid facet of the articular, which is slightly anteroposteriorly elongated with respect to the anteroposterior length of the quadrates, would allow limited anteroposterior movements of the jaw during this type of feeding behavior.