In-vitro puncture experiment using alligator teeth tracks the formation of dental microwear and its association with hardness of the diet.

With the development of dental microwear texture analysis (DMTA), there has been an increasing application of DMTA for dietary estimation in extant and fossil reptiles, including dinosaurs. While numerous feeding experiments exist for herbivorous mammals, knowledge remains limited for carnivorous reptiles. This study aimed to qualitatively and quantitatively evaluate the formation of dental microwear through repeated puncture of different types of food using isolated teeth from the American alligator (Alligator mississippiensis) in an in-vitro experiment. Eleven isolated teeth were mounted on a force gauge, and each tooth sample was repeatedly punctured 200 times into sardines (tooth sample size, N = 6) and crayfish (N = 5). The tooth surfaces were scanned using a confocal laser microscope before, during, and after the experiment to track changes in the tooth surface. Additionally, the maximum force during puncture was measured with the force gauge. Examination of surface roughness parameters before and after the experiment revealed a significant increase at the tooth apexes for both types of food. Furthermore, the trials with crayfish increased microwear depth and density more than the sardine trials. There was a significant positive correlation between the total force experienced by each tooth and the changes in surface roughness parameters in the crayfish trials, indicating that greater force results in more dental wear. The findings of this study are significant as they complement existing feeding experiments and comparative studies of wild species with different diets, and they demonstrate the effectiveness of experimental approaches in understanding the formation mechanisms of dental microwear.