Figure 5 in The killer's toolkit: remarkable adaptations in the canine teeth of mammalian carnivores

Figure 5. Morphospace of all upper and lower canine teeth measured in this study, showing shape variation in robustness, curvature and tip sharpness among killing techniques. Principal components analysis (PCA) of the Procrustes coordinates, where principal component 1 (PC1) is correlated with robustness and explains 50.63% of the shape variation present, and PC2 is correlated with curvature and explains 16.91% of the shape variation present. A, H, show the variation present in terrestrial mammalian carnivores across killing technique groups. B–G, I–N, show differences in upper and lower canine teeth for key killing techniques, as indicated by minimum convex hulls (upper canine convex hulls are depicted by a lighter shade of the family colour and lower canine convex hulls by a darker shade of the family colour). Killing technique groups represented are as follows: shake toss (B, I), nape throat (C, J), anterior bite (D, K), invertebrate feeder (E, L), head bite (F, M) and rarely (G, N). In O–Q, the lower case letters denote significant differences and are based on phylogenetically corrected analyses (series of phylogenetic ANOVAs, followed by pairwise post hoc testing for significant differences among killing technique groups) of robustness (PC1; O), curvature (PC2; P) and canine tip sharpness (based on standardized crosssectional areas; Fig. 2; Q).