Tooth-root form and function in platyrrhine seed-eaters.

Area of Science:

• Paleontology
• Primate Anatomy
• Biomechanics

Background:

• Tooth crown form aids in inferring primate diets.
• Understanding of tooth root form variation and its evolutionary basis is limited.
• Clinical studies highlight tooth root surface area's role in stress resistance.

Purpose of the Study:

• To investigate if primate tooth root form diversified with dietary specialization.
• To test the hypothesis that root form variation relates to diet.
• To quantify tooth root surface areas in platyrrhine primates with different diets.

Main Methods:

• Quantified maxillary canine and postcanine tooth root surface areas.
• Compared four platyrrhine species with varying dietary material properties: Cebus apella, Cebus albifrons, Chiropotes satanas, and Pithecia pithecia.
• Conducted pairwise comparisons between closely related taxa.

Main Results:

• Taxa consuming resistant seeds (C. apella, C. satanas) showed larger relative tooth root surface areas for seed processing teeth compared to less frequent consumers (C. albifrons, P. pithecia).
• Pithecia pithecia exhibited greater relative molar root surface area than Chiropotes satanas, aligning with Pithecia's more folivorous diet.
• Tooth root surface area varied along the tooth row, influencing bite-force gradients.

Conclusions:

• Primate tooth root form is closely related to occlusal loading patterns.
• Tooth root morphology likely diversified in response to dietary specialization.
• This research can enhance dietary inferences for extinct taxa and inform studies on feeding mechanics and evolution.