Caniniform pressure values for extant Crocodylia, their phylogenetic distribution, and inferred ancestral character states.

<p>(<i>A</i>) Members of the Alligatoridae are shown in blue, and members of the Crocodylidae+Gavialidae in green. The OLS regression equation describes the weak relationship between body mass and caniniform pressure. Note that slender-snouted piscivorous to semi-piscivorous ecomorphs (<i>Gavialis gangeticus and Crocodylus intermedius</i>, respectively) show exceptionally high-pressure values (outside the 95% confidence interval), and <i>Crocodylus johnsoni</i> shows pressures expected of animals nearly a magnitude in size larger. Other ecomorphs show much lower and similar relative values. The arrow indicates the typical ultimate shear strength of bone. (<i>B</i>) Ancestral character-state reconstruction using squared-change parsimony of size-standardized caniniform pressures. Residual caniniform pressure values are color coded to MPa (squared-change parsimony; squared length = 19.491). Vertical scale is in relative time, with the outgroup/ingroup root arbitrarily set to 1.0. High relative pressures were achieved independently in <i>Crocodylus intermedius</i>, <i>Gavialis gangeticus</i>, and <i>Crocodylus johnsoni</i>. Uncolored branches represent taxa for which the caniniform teeth were shed or broken, and so pressure estimation was not possible.