Incisor Geometry, Relief, and Diet in Anthropoid Primates With Implications for Antillothrix

Area of Science:

• Primate Paleontology
• Primate Ecomorphology
• Dental Anthropology

Background:

• Geometric measures of primate incisor size and curvature correlate with diet.
• Previous research has not extensively utilized dental topographic analysis for incisor shape variation.

Purpose of the Study:

• To assess the utility of Relief Index (RFI) and linear dimensions of central mandibular incisors (I1) as dietary proxies in anthropoid primates.
• To investigate incisor shape variation using methodologies beyond traditional geometric measures.

Main Methods:

• Measured linear dimensions, curvature, and RFI of central mandibular incisors (I1) in 107 extant anthropoids.
• Employed traditional and phylogenetic statistics, principal component analysis, and multinomial logistic regression to analyze dietary separations.

Main Results:

• Significant dietary differences were found in I1 height, width, breadth, and RFI, with no significant sexual differences.
• Phylogenetic ANOVAs confirmed significant dietary signals in these measures, robust despite phylogenetic signal.
• Predictive models incorporating I1 geometry and RFI demonstrated superior performance compared to geometry alone.

Conclusions:

• I1 RFI and linear dimensions serve as reliable dietary proxies in anthropoid primates.
• These findings can enhance future ecomorphological and paleontological analyses.
• A nuanced approach is recommended when applying I1 RFI or height as dietary proxies for fossil primates due to phylogenetic signal.