Effect of mollusc eating on human bone strontium levels

Empirical aspects of the movement of strontium through the food chain suggest that the level of bone strontium can be used as an indicator of the percentage of meat in human diet. In general, skeletal remains from agricultural peoples are expected to have high bone strontium levels relative to hunter-gatherers from the same geographical region because plants contain relatively higher amounts of strontium when compared with animal products. The results of the study described in this paper, however, indicate that the inclusion of molluscs as a component of the diet may produce the opposite of the expected strontium values. Burials from an Archaic (c. 2500 BC) hunting-gathering population excavated from Lu^o25, an archaeological site in northern Alabama, USA, exhibit a mean bone strontium level ( atomic absorption; neutron activation) that is higher than the mean level from an agricultural Mississippian (c. AD 1400) population ( atomic absorption; neutron activation) that was buried at the same site. The samples were analysed by two techniques (atomic absorption spectrometry and neutron activation analysis) and the results compared favourably; therefore, the results can be accepted as valid rather than being due to technique error. We propose that the ingestion of molluscs, whose meat is known to contain large amounts of strontium, has produced this reversal from expected results.     

Bone diagenesis in the European Holocene II: taphonomic and environmental considerations

We have applied cluster analysis to mercury intrusion porosimetry data from 219 archaeological bones (121 human and 98 animal) and soil chemistry data from 219 accompanying soil samples (1 per bone sample), to investigate the influence of soil chemistry on bone preservation. The samples chosen for the study were obtained from sites ranging in time from the pre-modern to the Mesolithic and were representative of burial environments across Europe (from the Baltic to the Mediterranean). These results represent the single largest database for archaeological bone preservation in the European Holocene to date and demonstrate the potential for large-scale diagenetic studies to help develop long term preservation strategies for our European heritage. Despite the variety of sites and environments, bones could be categorised into only four main diagenetic types. Furthermore, soil chemistry appears to significantly affect only one type of preservation, the pathway characterised by loss of mineral. In neutral to basic soils, taphonomy and in particular the differences between the treatment of human and animal remains, becomes the dominating factor in determining preservation. Using these results, strategies for heritage management of archaeological sites can be suggested; grouping sites into those requiring immediate excavation and those where in situ preservation is viable.     

Sources of variation in carnivore tooth-mark frequencies in a modern spotted hyena (Crocuta crocuta) den assemblage,Amboseli Park,Kenya

Distributions and frequencies of carnivore tooth-marks on large mammal long-bone fragments are commonly used to infer the timing of hominin and carnivore access to prey resources in archaeofaunal assemblages. The strength of these inferences, however, is limited by a broad and currently inexplicable range of tooth-mark frequencies across experimental and archaeological assemblages. Controlling for this variation first requires that the sources be identified. Several sources of variation are examined here in an analysis of tooth-marked bone recovered from a modern spotted hyena (Crocuta crocuta) den assemblage in Amboseli Park, Kenya. Results indicate that tooth-mark frequencies: (1) depend on fragment size, (2) vary across mammals of different size classes, (3) are highly variable across equivalent portions of different long-bone elements, and (4) on certain long-bone portions are correlated with bone density and can be depressed in archaeological assemblages subjected to density-mediated attrition. Stronger inferences based on tooth-mark frequencies will require that such variation be taken into consideration, and methods for doing so are suggested.     

Multi-element analysis for dietary reconstruction at a balearic Iron Age site

The number of studies using trace elements as indicators of diet has increased with time, but the majority have used few elements and a small sample. The present study has as a principal objective a multi-element analysis of diet in a large sample in which diagenetic changes have been shown to be unimportant. The analysis was made using concentrations of seven elements—Sr, Ba, Mg, Cu, Zn, V and Ca—in 197 individuals from the necropolis of ‘S' Illot des Porros’ (Majorca, Spain). The results show that these individuals would have had a mixed diet with a high meat component, principally of marine origin (molluscs and fish), but with an important consumption of seeds and cereals and a low proportion of vegetables.     

On the Origin of the Green Colour of Archaeological Bone Artefacts of the Gallo‐Roman Period

Recent findings in the city of Reims have lead to the discovery of manufactured bone objects coloured in green throughout their entire volume. In order to discover the intentional nature of the colouration and to propose a colouration mechanism, modern ox bones have been coloured in the laboratory. Bones with a hue similar to that of the archaeological artefacts have been obtained by boiling in an acidic brine in a copper vessel. A combination of infrared spectroscopy, X‐ray diffraction and transmission electron microscope observations did not reveal the speciation of copper, but allowed us to validate the colouration process and to discuss the intentional origin of the colouration.     

Bone preservation in human remains from the Terme del Sarno at Pompeii using light microscopy and scanning electron microscopy

Archaeological bone can show marked and complex alterations depending on the environment in which it was buried. In this study, the state of preservation of 27 femurs recovered from the archaeological site of Pompeii was evaluated by light microscopy and scanning electron microscopy. Most of the bone samples, prepared by the grinding method, showed good histological preservation, although they were characterized by microfissures (microcracking). Nine bone samples showed different states of histological preservation, including worst preservation (two femurs), due to diagenetic processes. Cryostat bone sections stained with thionin or 4′,6′-diamidino-phenylindole (DAPI) revealed the persistence of DNA within some osteocyte lacunae. Scanning electron microscopy analysis showed that ultrastructural characters, such as lamellae and collagen fibres, are recognizable only in unaltered bone. Our results reveal that most Pompeian samples are well preserved since they have a bone microstructure virtually indistinguishable from that of fresh bone. In methodological terms, although each of the various morphological methods used contributes information, histological and histochemical analyses are the most informative for studying the preservation state of bone and allow for rapid essential screening of archaeological bone.     

Changing patterns of carnivore modification in a landscape bone assemblage, Amboseli Park, Kenya

This study compares the landscape-scale taphonomic signal of carnivore modification to the surficial bone assemblage in Amboseli Park, Kenya as it was in 1975 and 2002–2004. Change in predator abundances over time provides a means of assessing the taphonomic signal of carnivore-mediated bone consumption and destruction under differing ecological conditions and varying levels of conspecific competition for resources. The landscape assemblage indicates taxonomic variation in the patterning of carnivore modification to ungulates of different size classes as well as within equivalent size classes. Analyses of long bone elements indicate that the differential destruction of limb ends and the strength of the correlation between limb end abundance and bone mineral density provide an indication of the intensity of carnivore modification to a faunal assemblage. The ability to infer levels of carnivore modification based on limb elements can provide faunal analysts with the tools to determine whether the taphonomic signals in the fossil record relate to carnivore modification, hominin transport of appendicular elements, or both.     

Stable isotopes and diet at Ancient Kerma,Upper Nubia (Sudan)

Carbon and nitrogen stable isotope values were measured from bone collagen extracted from archaeological Nubian human (n = 54) and faunal (n = 61) populations from the site of Kerma, Sudan. Collagen suitable for isotopic analysis was extracted from 22 faunal and 48 human samples from the Eastern cemetery site, dated to the Middle Kerma (c. 2050–1750 BC) and Classic Kerma (c. 1750–1500 BC) periods respectively. The isotopic data indicate that the human dietary regimen included a mix of C₃ and C₄ plant-derived components, with a larger C₄ component than previously reported in archaeological Egyptian Nile Valley populations. Elevated δ¹⁵N values are attributed to consumption of dietary resources from a ¹⁵N-enriched terrestrial ecosystem. The faunal isotope data also indicate the consumption of C₃ and C₄ plants. The large range of δ¹³C values measured in both the human and faunal samples supports previous work suggesting that a significant portion of the populations buried at Kerma may have originated elsewhere, further confirming the Nile Valley as a major corridor for population movement in the region.     

The consilience of historical and isotopic approaches in reconstructing the medieval Mediterranean diet

During the Middle Ages, the economies of Europe, the religious directives involving dietary requirements, and the general human subsistence base were transformed. These complicated and intertwined issues are starkly revealed in an isotopic study of two inland Italian human populations that are separated by approximately 850 years in time. Stable carbon (δ¹³C) and nitrogen (δ¹⁵N) isotopic values observed in human dentin and bone collagen from the sites of early medieval Castro dei Volsci and late medieval Rome are consistent with diets that differed substantially. As the North Atlantic opened to fishing and food preservations methods improved, Mediterranean peoples increased their fish consumption dramatically, and in doing so, met the religious directives of the Catholic Church. By analyzing both teeth and bone collagen within individuals, long-term feeding behaviors are documented, and the utility of last erupted teeth collagen as sources of adult dietary information is established. This study offers the first physical evidence of this new economic reality linking the Atlantic and Mediterranean economies at the end of the Middle Ages.     

Stable oxygen (δO) and hydrogen (δD) isotopes in ovicaprid dentinal collagen record seasonal variation

Understanding paleoenvironmental conditions, including the frequency and amplitude of seasonal variation, is crucial to understanding a wide array of human behaviors in prehistory. In vertebrate calcified tissue, inorganic oxygen isotopes derived from apatite have been widely used as a proxy for paleoenvironment and seasonality in the archaeological record. However, organic sources of δ¹⁸O and δD in mineralized tissue have remained largely unexplored. Here we measure the oxygen (δ¹⁸O) and hydrogen (δD) composition of dentin collagen sequentially sampled from the lower cheek teeth of four modern ovicaprids from the Baga Gazar'in Chuluu (BGC) region of the Gobi Desert of Mongolia. A significant correlation between trends in hydrogen and oxygen isotope values within individual teeth was identified. The amplitude of isotopic variation observed in sampled tooth dentin is similar to the yearly range of hydrogen and oxygen isotopic variation observed in meteoric precipitation for the region. These data indicate that dentin collagen δ¹⁸O and δD isotopic values reflect seasonal variation in the organic oxygen and hydrogen isotopic composition of diet and ingested water. We argue that paired measurements of dentin collagen δ¹⁸O and δD appear to be reliable seasonal climatic indicators.