Foraging substrate
We hypothesized that snakes feeding on the ground benefit from the
support of a solid substrate to capture, manipulate, and swallow their
prey, while arboreal species must deal with gravity and the weight of
their body and prey. Aquatic snakes, on the other hand, need to deal
with prey buoyancy. Our results indicate a significant difference in
tooth shape between terrestrial and aquatic feeders, but not in tooth
length. Aquatic snakes have an elbow-like tooth (Fig. 4 Homalopsis
buccata , Fig. 5: Laticauda colubrina, Subsessor bocourti ), that
is highly medially curved, with a very thin and sharp tip that may be
advantageous to prevent prey escape (Fig. 3 & 5). Their pulp cavity
runs almost to the tip of the tooth, so the layer of hard tissue is
smaller in those teeth which may provide them with more flexibility than
terrestrial species. Terrestrial species usually coil around their prey,
thus restricting their movement but aquatic snakes usually do not
restrain their prey. This may impose forces on the teeth coming from all
directions. Thus, having more flexible teeth may be advantageous for
aquatic species. This hypothesis remains to be tested but the teeth of
aquatically feeding snakes are weakly ankylosed (Savitzky, 1983),
suggesting another adaptation to prevent failure of these slender and
sharp teeth (Patchell & Shine, 1986).