ESR dating of a toxodon tooth from a Brazilian karstic cave

A pre-molar of a Toxodon platensis (sp), a large mammal that inhabited the forests of Southeast Brazil during quaternary times, was dated by electron spin resonance (ESR). Enamel and dentine were separated giving the following archeological doses (AD): (4.0 ± 0.8) and (11 ± 2) Gy, respectively. This difference was explained by the higher content of Uranium in dentine (25.1 ± 0.3) ppm as compared to enamel (0.37 ± 0.03) ppm. Taking account of the internal dose contribution to the AD, the age obtained is (6.7 ± 1.3) ky BP for dentine and (5.0 ± 1.6) ky BP for enamel.