How did our masticatory system evolve? Investigating bone and teeth microstructure in extant and fossil apes through X-ray synchrotron microtomography

Teeth and the bony structures that support them, mandible and maxillae, are key sources of evolutionary information about taxonomy, life-history, growth rates, diet and health.

Yet, new technologies, such as synchrotron radiography, are revealing a whole new dimension of information by providing micron-level detail on internal and external structures that throw new light on patterns of diversity and processes of diversification.

These novel technologies have only rarely been applied to fossil hominids - our direct hominin ancestors as well as the ancestors of living great apes; the single study of an australopithecine fossil by Beaudet and colleagues (2021) shows their immense potential.

This project aims at generating, for the first time, a large comparative dataset of synchrotron x-rays of fossil and contemporary African apes, including hominins, building on the collaboration by Beaudet with the new Diamond Light Source in the United Kingdom and Mirazon Lahr with the National Museums of Kenya, as well as develop new protocols of data capture and analysis.

Through these, the project will establish the diversity in growth rates of different elements of the masticatory system of apes, describe the diversity observed in internal dental structures of taxonomic and biological relevance, provide age-atdeath estimates of immature specimens that will greatly enhance our understanding of the evolution of hominid lifehistories.