Diet is a key component in primate evolution, as it reflects how species respond and adapt to their environment. This project focuses on analyzing the recent evolution of dietary behavior in colobus monkeys, baboons, and vervet monkeys in the Middle Awash region (Ethiopia), during a time span between approximately 158,000 and 100,000 years ago.

The study is based on two exceptionally rich fossil assemblages from the sedimentary beds known as Chai Baro (~158 ka) and Faro Daba (~100 ka), both part of the Halibee Member formation. In total, dental remains from nearly 900 individuals have been recovered, representing an unprecedented sample size for this kind of analysis. The taxonomic distribution is as follows: Colobus cf. guereza and cf. Chlorocebus are represented at Faro Daba, while Papio hamadryas ssp. and cf. Chlorocebus are predominant at Chai Baro.

The project will apply Dental Microwear Texture Analysis (DMTA), a non-destructive technique that allows recent diet to be inferred from microscopic wear marks created during chewing—on both the occlusal surface (reflecting the last days of life) and the buccal surface (reflecting the last few months).

This approach will help evaluate whether there was seasonal variation in the diet of these primates and, in the case of cf. Chlorocebus, compare the findings with postcranial evidence suggesting more arboreal behavior in Faro Daba individuals. This will test the hypothesis of behavioral flexibility, likely related to the ecological changes observed between the two time periods.

The results are expected to provide unprecedented data on the diet of fossil cercopithecids, as well as a new interpretation of their recent evolutionary history, offering key insights into how these groups may—or may not—have adapted to environmental challenges.