Alejandra Ortiz Rivarola

Grant Type

Post PhD Research Grant

Institutional Affiliation

Arizona State U.

Grant number

Gr. 9352

Approve Date

October 5, 2016

Project Title

Ortiz Rivarola, Alejandra, Arizona State U., Tempe, AZ - To aid research on 'A Comprehensive Analysis of the Deciduous Dentition of Plio-Pleistocene Hominins'

Preliminary abstract: Dental features are used extensively in taxonomic allocations and phylogenetic reconstructions of the human fossil record. Most of this work, however, has focused on permanent teeth. Comparatively less study has been devoted to the hominin deciduous dentition, and therefore its contribution to the better understanding of human evolutionary history has been limited. This disparity is particularly evident in early hominins from East Africa. This project attempts to fill these gaps by conducting a comprehensive analysis of the deciduous dentition of Plio-Pleistocene hominins using state-of-the-art techniques. A total of 86 subadult individuals recovered from Plio-Pleistocene deposits in Ethiopia, Kenya, Tanzania and South Africa will be examined in a comparative framework that will also include reference samples of extant humans and great apes. Analyses will be conducted on 3D virtual models derived primarily from microCT. A series of variables will be collected on these models, including crown and cervical outlines, crown and cusp areas, cusp angles, dental tissue proportions and dental wear. This project will explore deciduous dental variation within and between groups and assess the systematic status of several isolated deciduous teeth whose affinities remain uncertain. Data will also be analyzed from a developmental perspective in order to provide a better understanding of the source of crown shape variation at both macro and micro evolutionary levels, as well as to make inferences about the pace of reproduction and weaning behavior in Plio-Pleistocene hominins.