Fig. 3. Isometric scaling of independent contrast values for Odontomachus species. OLS regressions of normalized independent contrast values (IC) for body mass, jaw length and jaw mass against head width, with intercept set to the origin. All have slopes that do not depart significantly from null hypothesis of isometry for linear scaling (slope=1) or for mass scaling (slope=3), as follows: jaw length: P=0.0053, slope=1.12, 95% confidence interval for slope=0.61–1.63, r²=0.75; jaw mass: P=0.0018 slope=3.26, 95% CI=2.07–4.45, r²=0.82; body mass: P<0.001, slope=2.94, 95% CI=2.03–3.85, r²=0.87.