Correspondence between tooth shape and dietary biomechanical properties in insectivorous microchiropterans

Question: Do the biomechanical properties of the diet influence the tooth shape of insectivores? We examined dietary 'intractability', the extent to which structural strength, toughness and stiffness of a food are increased, roughly equivalent to 'hardness'. Hypotheses: The following three factors may cause discrepancies in tooth form in animals with different diets: (1) optional functional form: (2) risk of tooth fracture; and (3) amount of wear. Data studied: Functional parameters of molar shape based on engineering principles for three intractable- and three tractable-feeding microbats. Conclusions: There were no consistent differences in the functional parameters with diet. However, discrepancies within families indicated that the effectiveness of teeth of intractable feeders tended to be lower. The differences found arguably relate more to the risk of tooth fracture and increased wear. It appears that increased structural strength is the main difference in intractable diets. requiring greater robustness of the teeth, which reduces the functional efficacy.