3-2 Sat Jan 2 Integrating tooth shape with strike mechanics in the process of prey capture in Boa constrictor Ryerson, WG*; Van Valkenburg, T; Saint Anselm College; Saint Anselm College wryerson@anselm.edu http://ryersonlab.wordpress.com
Snakes, with the obvious exception of the fangs, are considered to lack the regional specialization of tooth shape and function that are exemplified by mammals. Recent work in fishes has suggested the definition of homodont and heterodont are incomplete without a full understanding of both the morphology, mechanics, and behavior of feeding. To further test this hypothesis, we investigate changes in tooth shape along the jaw of Boa constrictor and correlated these changes with the strike kinematics of boas feeding on rodent prey. We divided the upper and lower jaws into thirds, and calculated the curvature and of each tooth of the jaws as well as those found on the palatine and pterygoid bones. For strike kinematics, we filmed six adult boas striking at previously killed rats. We determined the regions of the jaws that made first contact with the prey, and extrapolated the relative positions of those teeth at that moment. We further determined the roles of all the teeth throughout the prey capture process, from the initiation of the strike until constriction began. We found that teeth in the anterior third of the lower jaw are the most upright, and that teeth become progressively more curved posteriorly. Teeth in the upper jaw are more curved than the lower jaw, with the exception of the most posterior lower jaw, and there are no regional differences among teeth in the upper jaw. A close examination of the strike kinematics revealed that the anterior portion of the lower jaw was the most frequent point of first contact. The momentum from the strike caused the upper jaws to rotate over the rat. The more curved teeth of the upper jaw slid over the rat unimpeded until the snake began to close its jaws. The curved teeth of the palatine and pterygoid bones assist in the process of the swallowing.