Interpreting food processing through dietary mechanical properties: a Lemur catta case study.

Area of Science:

• Primate dental morphology
• Paleoecology
• Bio-mechanics

Background:

• Dietary mechanical properties influence consumer ingestion and mastication.
• Ring-tailed lemurs (Lemur catta) in Madagascar show extreme dental wear linked to processing Tamarindus indica fruits.

Purpose of the Study:

• To investigate the mechanical properties of Tamarindus indica fruits.
• To correlate these properties with dental morphology changes in ring-tailed lemurs.

Main Methods:

• Measured fracture toughness, hardness, and modulus of various food items using a portable mechanical tester.
• Analyzed dental morphology and wear patterns in ring-tailed lemur populations over multiple years.
• Conducted controlled cutting tests on ripe Tamarindus indica fruit shells.

Main Results:

• Tamarindus indica fruits are the hardest and toughest foods consumed by ring-tailed lemurs.
• These fruits are large, frequently eaten, and require numerous bites, leading to significant mechanical stress.
• Controlled tests revealed crack formation in the fruit shell, mirroring observed dental micro-cracking in lemurs.

Conclusions:

• The extreme dental wear in ring-tailed lemurs is primarily caused by micro-cracking from repeated loads.
• The mechanical and physical properties of Tamarindus indica fruits, combined with lemur enamel susceptibility, are responsible for the observed dental damage.