Earth Sciences Commons^™

Adaptation To Hard-Object Feeding In Sea Otters And Hominins, Paul Constantino, James Lee, Dylan Morris, Peter Lucas, Adam Hartstone-Rose, Wah-Keat Lee, Nathaniel Dominy, Andrew Cunningham, Mark Wagner, Brian Lawn

Paul J. Constantino

The large, bunodont postcanine teeth in living sea otters (Enhydra lutris) have been likened to those of certain fossil hominins, particularly the ’robust’ australopiths (genus Paranthropus). We examine this evolutionary convergence by conducting fracture experiments on extracted molar teeth of sea otters and modern humans (Homo sapiens) to determine how load-bearing capacity relates to tooth morphology and enamel material properties. In situ optical microscopy and x-ray imaging during simulated occlusal loading reveal the nature of the fracture patterns. Explicit fracture relations are used to analyze the data and to extrapolate the results from humans to earlier hominins. It is shown …