Dietary Adaptation in Paranthropus robustus Postcanine Teeth
M. C. O'Hara, S. Chapple, P. Mahoney, W. S. McGraw, Gary T. Schwartz, M. M. Skinner, D. Guatelli‐SteinbergABSTRACT
Objectives
Recent studies of
Paranthropus robustus
crania identified temporal trends in features associated with increased bite force production, coinciding with environmental shifts toward more arid conditions. To test whether the evolution of postcanine teeth also reflects increasing mechanical demands associated with hard food consumption, we analyzed trends in the architecture of
Materials and Methods
2D mesial sections were created from microCT scans of upper premolars ( n = 24), upper molars ( n = 14), and lower molars ( n = 16) from multiple South African sites. Descriptive statistics, Mann–Whitney U tests, and Jonckheere‐Terpstra tests were used to identify significant differences over time, with Holm‐Bonferroni corrections applied for multiple comparisons.
Results
Significant temporal trends existed in premolar morphology with increased crown area (CA), absolute crown strength (ACS), overall enamel thickness (AET and RET), and increased enamel thickness over the occlusal half of the tooth. Upper molars increased in CA but no other measured variable. Lower molars showed no significant temporal trends in any measured variable.
Discussion
These results suggest rapid dental evolution in response to dietary pressures, with varying and independent rates of change between different tooth types. These findings support the hypothesis that selection resulted in shifts to