The prevalence and timing of enamel hypoplasia in the bonobo, Pan paniscus [Coolidge, 1933]

Systematic analysis of prevalence and timing of developmental stress in the bonobo, Pan paniscus, is accomplished through examination of enamel hypoplasia (EH), a non-specific stress-induced defect permanently recorded in the developing dentition.; Bonobo crania (n = 182) housed at the Royal Museum for Central Africa in Tervuren, Belgium, are grossly examined under natural and artificial oblique lighting for presence of EH. Three methods are employed to determine the timing of linear enamel hypoplasia (LEH). (1) Imbricational enamel formation schedules are created for bonobo teeth (n = 6) by counting the number of perikymata from the cemento-enamel junction to the occlusal surface. (2) Caliper measured defects are calculated as a proportion of crown height and multiplied against crown formation times for bonobo and chimpanzee to establish age at which defects form (n = 490 teeth). (3) Using scanning electron microscopy, tooth crown surfaces (n = 22) are examined and perikymata counted within and between enamel defects. (Abstract shortened by UMI.)...