Postcanine tooth size in female primates.

Area of Science:

• Primate Paleontology
• Comparative Anatomy
• Evolutionary Biology

Background:

• Allometric studies on mammal tooth size often yield unexpected results regarding energy needs and dental function.
• Understanding the relationship between tooth size, body mass, and reproductive metabolic costs is crucial for evolutionary studies.

Purpose of the Study:

• To investigate the relationship between postcanine occlusal surface area, body size, and the metabolic demands of pregnancy and lactation in female primates.
• To test hypotheses regarding relative dental size in females compared to males and its correlation with neonatal size.

Main Methods:

• Collected tooth and body size data from 38 primate species from existing literature.
• Analyzed the correlation between female postcanine occlusal surface area, body size, and neonatal size.
• Assessed the relationship between relative female tooth size and the degree of sexual dimorphism in body weight.

Main Results:

• Females do not consistently exhibit relatively larger teeth than males.
• 21% of species showed females with less occlusal surface area than predicted by male regressions.
• No correlation was found between relative female tooth size and relative newborn size across higher primate taxa.
• The degree of female dental enlargement is most closely related to sexual dimorphism in body weight (correlation of 0.87).

Conclusions:

• The hypothesis that females should have relatively larger teeth to meet reproductive energetic costs is not consistently supported in primates.
• Sexual dimorphism in body weight, rather than neonatal size, is the primary predictor of relative postcanine tooth enlargement in female primates.
• Even in species where females require more food, tooth size dimorphism does not always reflect this, particularly in weight-monomorphic species.