| Summary: | Differential bone loss caused by various taphonomic agents introduces serious bias in archaeozoological assemblages and interferes with the estimation of species proportions, mortality profiles, sex ratios and patterns of skeletal element representation. Inherent characteristics of bones have been studied in order to assess the degree to which such factors influence bone loss in order to help archaeozoologists to differentiate between human selection and natural attrition related to the bones' resistance to destruction. Bone density is the main characteristic studied. An experiment to measure the density of bones of ox, pig and sheep has been carried out. A comparison between the density values found in this research and in published data has been carried out. It was found that methodological improvement is needed in respect of estimating bone volume and porosity, parameters that influence the accuracy of the density measurements. Species, breed, sex and age differences were also indicated as influencing differential survival of bone in an archaeological context. Large samples were considered necessary in order to establish the differences noted and improve the accuracy of the measurements. A gnawing experiment in which dogs were fed on pig, sheep and ox bones was carried out with the aim of checking if the attrition caused is related to the bone density. The bones of the three species exhibited different degrees of attrition. The destruction of the bones was found to be sometimes related to their density. However, density was not the only factor to influence bone survival. Size was also believed to have determined the bone survival. Age and shape were other possible influential factors. When density models were applied to the gnawing experiment data, it was found that only in the case of pig bones was density mediated attrition indicated. Bone assemblages from three sites, one from Greece and two from England, were studied. A method of diagnostic zones was used to provided a detailed view of what parts of the bones were present. Comparison of the bone portions surviving at the three sites for the species ox, sheep and pig was undertaken in order to decide whether or not similar patterns in bone survival emerged across the sites. Some uniform patterns were attested, often related to the bone density but also to the age of fusion and, sometimes, to the shape and morphological characteristics of the bone. Skeletal representation tables were constructed using two methods: one based on the diagnostic zones as the counting unit and the other on the epiphyseal portion. The first system was found to give more accurate information in terms of understanding the processes that have affected bone assemblages. Estimations about possible density-related patterning in the bone assemblages were offered and correlations were then carried out between the element frequencies and the density models. In most cases the results of the correlation agreed with the predictions whilst in few occasions different interpretations were indicated. Finally, differences between density models of adult and young specimens were found implying that separate examination of fused and unfused specimens by different age models provides a deeper understanding of bone assemblages.
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