Relative age determination of the skull of the chacma baboon (Papio ursinus)

Abstract

Relative age determination was carried out on the skulls of 261 chacma baboons (Papio ursinus), 117 from the Loskopdam Nature Reserve and 144 from the Messina district in the Northern Transvaal. Seven age groups were distinguished, of which classes I-IV were based on the eruption and displacement of milk and permanent teeth. Adults with a complete set of permanent dentition were subdivided into three additional classes (V- VII), mainly on the basis of the degree of molar attrition. For comparative purposes the pattern of maturation of craniometric parameters which reflect the general size and shape of the skull, as well as the degree of closure of ectocranial sutures, were treated on the same basis. From this it is apparent that a most reliable estimate of relative age can be obtained by using all the above-mentioned criteria.