Fig. 2: Correlations between linear measurements of
the tooth. a. Tooth length and mean angle, b. tooth length and
maximal angle, c. mean angle and maximal angle. Each dot represents one
species and is colored and shaped according to the main mechanical
challenge encountered during feeding (legend above the graph).
The main mechanical feeding challenge is significantly related to the
three measurements (LC: F=4.03, P=0.03, mean angle:
F=4.49, P=0.02, max angle: F=5.06, P=0.01). Pairwise comparisons show
that snakes that must hold their prey have longer teeth than snakes
feeding on hard prey and snakes feeding on slippery prey which both have
a larger mean and max. angle of curvature than snakes feeding on hard
and long prey (Fig. 3, Table 1).
Prey hardness is also related to tooth length (F=5.93, P=0.01), mean
curvature (F=6.38, P=0.01), and the maximal angle of curvature (F=4.93,
P=0.03). Snakes feeding on hard prey have shorter teeth than snakes
preying upon soft prey. Snakes feeding on prey of intermediate hardness
have more curved teeth than durophagous species (Fig. 3, Table 1).
The medium in which species feed is also significantly related to the
mean (F=9.97, P=0.001) and maxima of curvature (F=5.14, P=0.03) but not
to tooth length (F=2.61, P=0.15). Snakes that forage under water have
more curved teeth than snakes feeding on the ground. The average
curvature of snakes feeding in trees is almost significantly higher than
terrestrial species (t=-2.34, P=0.052, Fig. 3).
Finally, prey shape is not significantly related to the length and
curvature (all P>0.3).