Morphological adaptation to diet in platyrrhine primates

Area of Science:

• Primate morphology and evolution
• Comparative functional anatomy
• Primate feeding ecology

Background:

• Platyrrhine monkeys (New World monkeys) exhibit diverse dietary habits within the Suriname rainforest.
• Understanding the relationship between craniodental morphology and diet is crucial for evolutionary studies.

Purpose of the Study:

• To investigate the correlation between jaw and tooth morphology and dietary behavior in eight coexisting platyrrhine species.
• To identify specific morphological adaptations linked to specialized diets and protein acquisition.

Main Methods:

• Geometric morphometrics were used to calculate Z-scores for feeding apparatus features (e.g., tooth dimensions, jaw robusticity, jaw muscle leverage).
• Morphological data were compared with naturalistic dietary profiles (proportions of fruit, seeds, leaves, fauna).

Main Results:

• Species with restricted diets showed exclusive specialized features, often related to specific protein sources.
• Frugivores like Ateles paniscus displayed broad incisors; seed predators (Chiropotes satanas, Pithecia pithecia) had large canines and robust mandibles.
• Omnivores showed a mix of features, with muscle leverage patterns indicating different foraging strategies (masseter vs. temporalis dominance).

Conclusions:

• Craniodental morphology in platyrrhines is strongly influenced by dietary niche, with specializations supporting specific food exploitation.
• Muscle leverage patterns reflect functional demands related to diet, such as seed predation or foraging.
• Small body size in Saguinus midas may constrain the evolution of enlarged dentomandibular structures.