High prevalence of enamel hypoplasia in an early Pliocene giraffid (Sivatherium hendeyi) from South Africa

Almost two thousand mandibular teeth of the short-necked giraffid, Sivatherium hendeyi, from Lange-baanweg, South Africa, were examined for dental pathologies. Enamel hypoplasia is present in 0 to 34 percent of deciduous teeth and 40 to 75 percent of permanent teeth. No linear enamel hypoplasias were found in the deciduous teeth, while 20 to 35 percent of the permanent teeth have this defect. The linear defects at the base of the first molar are thought to relate to stress associated with weaning. The defects in the later erupting permanent teeth are, however, widely distributed over tooth crowns. Several linear defects are present on some teeth suggesting that these stress episodes were periodic. We propose that poor environmental conditions, possibly seasonal nutritional stress, are responsible for the observed enamel hypoplasia in the permanent dentition of S. hendeyi. This study provides new insight into the current understanding of the paleoenvironment at Langebaanweg, South Africa.