Is the skull of a near obligate herbivore such as the giant panda relatively better adapted to resist high reaction forces generated at the molars, where bamboo is primarily

processed? With respect to diet and ecology in the extinct A. africanum, we address the following: 2. Regardless of whether A. africanum was a more regular predator of large prey or whether it consumed a DAPT purchase high proportion of large vertebrate bones relative to extant species, if either interpretation is correct, then we would predict that this species was capable of generating relatively high bite forces and that its skull was well-adapted to sustain such forces. In comparative FEA, single specimens are routinely used to represent entire species. An assumption here is that interspecific differences outweigh intraspecific ones. Our analyses include FEMs of two polar bears. 3. We ask whether the mechanical behaviours of these two conspecifics are more similar to each other than to other species. Although our sample is tiny, it will nonetheless allow a limited first test of this assumption. Seven finite element models were assembled from computed tomography JNK inhibitor cell line (CT) data representing five extant species

(brown bear, Asian bear, black bear, polar bear and giant panda) and one fossil ursid A. africanum (SI Table S1). For extant taxa, preprocessing followed the previously published protocols (McHenry et al., 2007; Wroe et al., 2007; Moreno et al., 2008; Wroe, 2008; Degrange et al., 2010; Wroe et al., 2010). The fossil skull (SAM-PQ 45062) that formed the basis of our A. africanum FEM (and see SI) is without obvious deformation but missing data comprise the majority of the left parietal, frontal bones Roflumilast and the palate. Virtual reconstruction to replace these missing data develops previously published protocols (Wroe et al., 2010). Preprocessing of the extant bear material also largely follows the published methodology (McHenry et al., 2007), but with the surface

and solid meshes generated in Harpoon® (version 3.6, Sharc Pty Ltd., Manchester, UK). Each cranium comprised ∼1.5 million elements. To reconstruct A. africanum, we first used Rhinoceros® (version 4, McNeal & Associates, Seattle, WA, USA) to mirror the right parietal and frontal bones. Then, a polar bear source mesh was warped to fit A. africanum in Landmark® (version 3.0, Institute for Data Analysis and Visualization, Davis, CA, USA). Six point primitives and 150 curved primitives were placed in Landmark on the interior and exterior surfaces of the source and target (A. africanum) meshes, allowing the polar bear cranium mesh to be warped to the same shape of A. africanum. A solid mesh was generated in Harpoon® from this complete surface mesh. For all subsequent analyses, FEA was performed using Strand7 (version 2.4.4, Company: Srand7 Pty Ltd., Sydney, Australia).