Only a small fraction, just 21 out of over 400 teeth examined, exhibited fractures, indicating that early primates likely favored a diet rich in soft foods. The analysis, focused on fossilized primate teeth from the Fayum Depression in Egypt, suggests that these ancient creatures predominantly consumed easily chewable items like fruits, as opposed to harder substances such as seeds or nuts that could cause dental damage.
The teeth under scrutiny, belonging to five primate genera like Propliopithecus, Apidium, and Aegyptopithecus, are approximately 29 to 35 million years old. This timeframe corresponds to the existence of the last common ancestor of apes, including humans, and African and Asian monkeys. The study, published in the American Journal of Biological Anthropology on December 13, sheds light on the dietary habits of early primates and offers insights into the evolution of human diets.
Ian Towle, a dental anthropologist at Centro Nacional de Investigación sobre la Evolución Humana in Burgos, Spain, emphasizes the significance of studying dental damage caused by food millions of years ago to understand the evolutionary changes in our own diets over time. During the research conducted while at the University of Otago in New Zealand, Towle and his colleagues found that only 5 percent of the analyzed teeth, or 21 teeth, exhibited visible fractures.
This rate falls at the lower end of the spectrum observed in living primates, where 4 to 40 percent of teeth typically show signs of food damage. The study highlights the contrast between species, with forest-dwelling monkeys like the sooty mangabey, regularly consuming hard food, potentially exhibiting fractures in up to half of their teeth. In contrast, species like chimpanzees, primarily consuming soft foods such as insects and fruit, may have fewer than 10 percent of chipped teeth.
Interestingly, two Propliopithecus individuals in the study displayed cavities, suggesting a preference for sweet fruits as their soft food source. This finding supports previous studies indicating that fruits were part of the early diets in the evolutionary history of monkeys and apes. However, the study also acknowledges the challenges in correlating tooth conditions with actual diets, as different methods may yield varying results.
Debra Guatelli-Steinberg, a dental anthropologist at the Ohio State University in Columbus, notes that while tooth shape and wear analysis in previous work suggested that some primate species ate hard items, the new study’s focus on chipping provides a longer dietary record. The research emphasizes the need to explore the potential reasons for disparities in results obtained through different techniques, prompting further investigation into the complexities of ancient primate diets.
