Figure 3.

Perissodus species exhibit sided differences in craniofacial shape. (A) Perissodus straeleni shows marked differences in the entire geometry of the skull associated with a general lengthening of the preorbital region (shaded region of the grids) of the skull on the side facing prey. (B) Lever models of the lower jaw were used in order to evaluate the functional implications of jaw asymmetry. (C) Analysis of variance, comparing the mechanical advantage of opening and closing lever systems in the lower jaw, predicts sided differences in the force and speed of the lower jaw in both P. straeleni and P. microlepis.