Fig. 2
Vertebrate teeth grow following the power cascade model, showing linear change in log Radius with log Distance from tip. a Measurement of Radius and Distance for Tyrannosaurus rex (UWBM 99000) lower right tooth 2 (shown in light green in b), which fits a linear model with R2 = 0.997. Radius = √ (cross-sectional area/π). b Teeth from all vertebrate groups show a linear pattern on log-log axes. Linear regression gives R2 > 0.994 for all teeth shown, other than snake fang where R2 = 0.954 (R2 = 0.999 excluding base 20%). EDJ, enamel-dentine junction. c Power cones vary depending on Slope (from conical to blunt) and Intercept (from wide to narrow) of the Log Radius-Distance plot