Histological methods for estimating age at death using osteon population densities for the rib, clavicle, and rib and clavicle combined are presented. Predicting formulas were generated from a sample of 40 individuals of known age, sex, and race. Independent samples of 12 ribs and 7 clavicles were used to test the formulas. Mean differences between known and predicted ages were 1.1 years, 2.6 years, and 3.4 years for the clavicle, rib and clavicle combined, and rib formulas respectively. An analysis of variance found no significant differences among the means for predicted and known ages. Since the formula based upon rib and clavicle combined has the higher standard error and r2, and includes data from different bones, it should provide better overall accuracy and reliability, and is recommended whenever both bones are available.

Surface areas of humeral and femoral heads scale largely as a function of body size. However, differences in the relative sizes of these articular surfaces are correlated with differential joint mobility and force transmission through fore- and hindlimbs. They can therefore assist interpretation of the positional behavior of extinct species. In this paper, we document variation in ratios of humeral head surface area to femoral head surface area among extant primates and other mammals. We then examine a group of extinct primates: the subfossil lemurs of Madagascar. Many Malagasy lemurs, including some giant extinct species with very long forelimbs and short hindlimbs, have relatively small humeral heads and large femoral heads. We explore the adaptive implications of this pattern.

Frost (1987a) proposed an algorithm for estimating the number of missing osteons that correspond to observed osteon population densities (OPD). Such an algorithm should allow more accurate estimates of bone remodeling rates for skeletal remains for which in vivo labeling is not possible. In order to validate the algorithm, it was tested on an autopsy sample of 44 ribs. Estimates of activation frequency (mu RC) and bone remodeling rate (Vf,r,t) using the new algorithm are in reasonable agreement with age-matched tetracycline-based values. Although mean values for activation frequencies (mu RC) and bone formation rate (Vf,r,t) generated by the algorithm were generally lower, they fell below 1 standard error for only an age category that included all ages above the 5th decade. It is now appropriate to apply the algorithm to archaeological skeletal remains.

With 3 plates and 2 figures in the text)The study of scale-correlated changes in the external dimensions and cross-sectional geometry of primate long bones is fundamental to our understanding of primate limb bone structural adaptation. To date, however, there have been no studies of the effects of mechanical loading on patterns of skeletal scaling at the microstructural level. To remedy this, we analysed patterns of microanatomical scaling in the humeri and femora of 107 adult primates belonging to the families Galagonidae and Cercopithecidae. Seven species were included in our analysis. Proximal, midshaft, and distal sections of humeri and femora of each individual were examined and secondary osteonal and cortical area were measured. Secondary osteonal area scales positively allometrically with cortical cross-sectional area and with body m a s This pattern holds generally for humeri and femora-both within and across families. However, there are striking dissimilarities in the relative strengths of the allometric coefficients for humeri and femora measured for different families. These distinctions appear to be related to differences in the ways in which fore-and hindlimbs are loaded. Such differences highlight the promise of microstructural data and the importance of examining the confounding effects of locomotory behaviour in studies of skeletal scaling.

An age at death estimation equation that uses rib histological variables presented by Stout and Paine was used to evaluate a skeletal population of individuals with a known age at death and cause of death from either malnutrition or the niacin deficiency disease pellagra. The sample was comprised of 26 autopsied black South Africans. Histological analysis of mounted thin sections involved the microscopic measurement of cortical area and a count of the number of intact and fragmentary secondary osteons for the entire cross-section of the rib. Rib osteon population density values were then calculated for each case. It was found that this equation under-aged individuals on average by 29.2 years. Overall, secondary osteon size and Haversian canals tended to be larger than expected, while cortical bone area was less when compared with a control population. The implications of these findings are critical given that many of the skeletal remains examined by forensic anthropologists come from marginalized backgrounds, including malnutrition. This research suggests that measurements based on healthy cases may not be useful in an analysis of individuals with poor diet and health. It is argued that new standards for histological age assessment methods need to be created that account for variation in the health status of individuals examined by forensic anthropologists.