Getting to the tooth of the matter a statistical test for functional homodonty


Meeting Abstract

32-5  Friday, Jan. 4 14:30 – 14:45  Getting to the tooth of the matter: a statistical test for functional homodonty COHEN, KC*; WELLER, HI; SUMMERS, AP; University of Washington ; Brown University ; University of Washington kecohen@uw.edu

Teeth tell a story of the interaction between predator and prey. If the teeth in a jaw look the ‘same’ we call them homodont; and if there is distinct regional specialization in size or shape they are heterodont. These are vague terms with no useful functional implication. Tooth shape affects function and has been explicitly tested and modeled – conical teeth are good for piercing, molariform teeth for crushing, and serrated teeth cut well. We are interested in the concept of homodonty and the conical tooth. There is a great deal of variation in the shape and placement of conical teeth. Anterior teeth may be larger than posterior ones, larger teeth may be surrounded by small ones, and patches of teeth may all have the same size and shape. We consider the pressure that a tooth can exert on prey; as often pressure is what leads to prey failure. We can calculate pressure from surface area and the distance a given tooth is along the jaw. Functional homodonty is then defined as all the teeth along the jaw bearing/exerting similar stress values despite position. We find conical teeth are functionally homodont when larger teeth are surrounded by smaller teeth. Suggesting a functional advantage to having a number of smaller teeth surrounding a singular large tooth. We hypothesize this tooth placement may allow an individual to grab prey upon puncture, rather than tear through and that smaller teeth quickly dissipate large stress forces away from the larger tooth. However, what constrains this system, as there is not an unlimited amount of teeth that can exist along the jaw. Moreover, teeth at the back of the jaw have little effect on the performance of teeth at the front of the jaw. We hypothesize that there is an optimal distance and surface area of smaller conical teeth in relation to larger teeth in functionally homodont dentition.

the Society for
Integrative &
Comparative
Biology