Data are presented documenting the timing of tooth calcification for the left mandibular dentition (I1-M3) based on a cross-sectional series of intraoral dental X-rays from a sample of 118 captive chimpanzees. Mean, median, and midpoint ages of attainment; standard deviations (SD); interquartile ranges (IQR); and age ranges were calculated for the eight developmental stages of these teeth. Minor differences with previous studies of chimpanzee dental development were found (Anemone et al. [1991] Am. J. Phys. Anthropol. 86:229-241; Anemone and Watts [1992] J. Hum. Evol. 22:149-153), but the similarities with previous studies are more striking despite the differences in samples. In contrast to other pongid studies, sex differences in developmental timing were documented, particularly for the canine. Regression models for age estimation from dental maturity scores were also presented. This chimpanzee standard is compared with human standards to determine absolute and relative differences in the timing of crown and root calcification. The overall period of canine development in both species is nearly identical, although those for crown and root formation are markedly different--making this tooth the most distinctive feature between chimpanzee and human dental development periods. Although the molars demonstrate differences in the timing of crown and root calcification periods, they are more proportional than for other teeth. This contributes to the difficulties in distinguishing between "human" and "chimpanzee" patterns of molar development. The developmental differences discussed are placed in perspective with consideration to microstructural and morphological features of chimpanzee and human teeth, and to overall growth periods in these species.

Tooth emergence data from a mixed-longitudinal sample of 58 chimpanzees of known age were analyzed using probit and survival techniques to produce median emergence ages, ranges of variability, and emergence sequences for primary and permanent teeth. Between-group comparisons were made to test for statistically significant differences in emergence ages. No such differences were found between right and left sides, or between maxilla and mandible, for any primary or permanent teeth. Male-female comparisons did demonstrate significant emergence-age differences for some teeth, although they were not always bilaterally symmetrical. More complete data are required to further clarify the nature of sex differences in tooth emergence in chimpanzees. Regression models for age prediction from the number of emerged teeth were generated and indicate that males achieve a given number of emerged teeth at a significantly later age than females. However, when fewer than five teeth have emerged, males are predicted to be younger than females. The sizable root mean square error values for these models suggest that this method of age prediction has limited usefulness owing to the amount of variability in timing of tooth emergence in chimpanzees. The implications of these data for studies on tooth emergence in early hominids are addressed.

The Raymond A. Dart Collection of Human Skeletons (Dart Collection) is housed in the School of Anatomical Sciences at the University of the Witwatersrand, Johannesburg, South Africa, and comprises one of the largest documented cadaver-derived human skeletal assemblages in the world. This collection originated in the early 1920s as a result of the efforts of Raymond Dart and continues to grow. The skeletons included represent varied indigenous and immigrant populations from southern Africa, Europe and Asia. This contribution documents the history of the collection and provides an updated inventory and demographic assessment of this valuable research collection. According to a recent inventory the Dart Collection currently comprises 2,605 skeletons representing individuals from regional SA African (76%), White (15%), Coloured (4%) and Indian (0.3%) populations. A large proportion of the skeletons (71%) represent males. The recorded ages at death range from the first year to over 100 years of age, but the majority of individuals died between the ages of 20 and 70. The Dart Collection has been affected by collection procedures based on availability. All of the cadavers collected before 1958, and large proportions subsequently, were derived from unclaimed bodies in regional South African hospitals. Some details of documentation (age at death, population group) are estimates and some aspects of the collection demographics (sex ratios) do not closely reflect any living South African population. Our inventory and analysis of the Dart Collection is aimed to assist researchers planning research on the materials from this collection.

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