Enamel Prism Angle Variation and Hard-Object Feeding in Cercopithecoids With Known Diets

Area of Science:

• Primate paleontology
• Dental microwear analysis
• Evolutionary biology

Background:

• Enamel prism orientation is crucial for tooth strength and wear resistance.
• Dietary hardness influences selective pressures on dental microstructure.
• Cercopithecoid primates exhibit diverse feeding strategies, from soft to hard objects.

Purpose of the Study:

• To investigate the relationship between enamel prism angles and dietary hardness in three cercopithecoid genera.
• To test if habitual hard-object feeders (durophagous) have higher prism angles than soft-object feeders.
• To compare prism angles between habitually durophagous and fallback hard-object feeding species.

Main Methods:

• Sectioning and microscopic imaging of primate molars.
• Measuring enamel prism and wear angles using ImageJ FIJI software.
• Statistical analysis (repeated measures regressions) to assess predictors of prism angle.

Main Results:

• Genus and wear angle were significant predictors of enamel prism angle.
• Cercocebus atys (habitual hard-object feeder) exhibited significantly higher prism angles than Lophocebus albigena and Cercopithecus.
• No significant difference in prism angles was found between Lophocebus albigena (fallback hard-object feeder) and Cercopithecus (soft-object feeder).

Conclusions:

• The enamel microstructure of fallback hard-object feeders is more similar to soft-object feeders than habitual hard-object feeders.
• The link between durophagy and enamel microstructure is not straightforward.
• Inferring durophagy in fossil primates based solely on enamel microstructure may be challenging.