Stable hydrogen isotopes of bone collagen in palaeodietary and palaeoenvironmental reconstruction

The stable hydrogen isotope ratios (δD) of bone collagen in archaeological human and animal samples demonstrate a trophic level effect, with increasing δD from herbivores to omnivores to humans, in steps of 10–30‰. In addition the archaeological sites studied (Yarnton, Eton Rowing Lake, Danebury Environs–Suddern Farm, and Windmill Hill in the UK, Balatonszárszó in Hungary, and Huari in Peru) demonstrate geographical variation in δD. The detection of manuring in prehistory by comparison of δ¹⁵N to δD values in humans and a local herbivore (cattle) is also considered. This work is the first to measure δD in a large number and range of archaeological samples, with several animal species and humans. It demonstrates unequivocally that δD is different between species in ancient material, increasing from herbivores to omnivores to carnivores.     

Manuring and stable nitrogen isotope ratios in cereals and pulses: towards a new archaeobotanical approach to the inference of land use and dietary practices

This paper explores the impact of animal manure application on the δ¹⁵N values of a broad range of crops (cereals and pulses), under a range of manuring levels/regimes and at a series of locations extending from northwest Europe to the eastern Mediterranean. We included both agricultural field experiments and areas where ‘traditional’ farming is practised. Our aim is to ground-truth interpretation of δ¹⁵N values in archaeobotanical crop remains as evidence of past growing conditions and husbandry practices. The results confirm the potentially radical impact of manuring on δ¹⁵N values in cereals, depending on manuring level, but indicate only a slight effect on pulses, which can fix atmospheric nitrogen. The expected geographical trend towards greater δ¹⁵N with increasing climatic aridity is not apparent, probably because the growing conditions for crops are ‘buffered’ through crop management. Each of these observations has fundamental implications for archaeobotanical interpretation of δ¹⁵N values as evidence of land use practices and (together with analysis of bone collagen/tooth enamel in potential consumers) palaeodiet.     

Taxonomic, anatomical, and spatio-temporal variations in the stable carbon and nitrogen isotopic compositions of plants from an African savanna

Stable carbon (δ¹³C) and nitrogen (δ¹⁵N) isotope ratios are commonly used to reconstruct palaeodiets and palaeoenvironments. The method is based on our knowledge of isotopic patterns in plants, which are subject to taxonomic and environmental variability. While previous researchers have addressed isotopic variability amongst plants, no studies have looked extensively at a broad suite of taxa over multiple temporal scales from within the savanna biome so as to provide baseline data for palaeodietary and palaeoenvironmental studies. Here we document variations in the isotopic compositions of plants collected over two years from the Kruger National Park, South Africa, with respect to species and anatomical differences, and the influences of geological substrate and spatio-temporal shifts in climate. Results show that environmentally-induced carbon isotopic variations in plants within this region are generally smaller than 2‰, which is lower than what has been previously reported for plants compared across multiple habitat-types. These data suggest that δ¹³C differences of 2‰ or more (or 1‰ if the diet is predominantly C₄) between animals from a given area reliably indicate real dietary differences. Plant δ¹⁵N values vary greatly between different microhabitats (by up to 4‰), responding to a range of environmental influences that may, in turn, significantly influence variation in animal δ¹⁵N values.     

Stable isotopic evidence for diet in a Roman and Late Roman population from Leptiminus,Tunisia

This study investigates the diet of the Roman and Late Roman population of Leptiminus on the Mediterranean coast of Tunisia. Stable carbon and nitrogen isotope analysis of human bone collagen and carbonate samples obtained from individuals buried in four cemeteries at Leptiminus was conducted in order to reconstruct the diet of the population, investigate the relative importance of marine vs. terrestrial resources, explore sex-, age-, and status-based variations in diet, examine temporal changes in the types of foods consumed, and compare the diet at Leptiminus with that of other Roman populations. The results of this study indicate that the residents of Leptiminus consumed a diet that was heavily reliant on terrestrial plant resources with the addition of a significant amount of marine resources. There were no significant sex differences in isotope values. In contrast, distinct dietary differences were seen between the adults and children. Nitrogen isotope values suggest that weaning began before the age of two and was completed by about 3 years of age, a finding consistent with previous isotopic studies of Roman samples. A temporal shift in diet is suggested by the nitrogen isotope values measured in samples from the most recent cemetery. A comparison of the data from Leptiminus with that derived from other Roman sites indicates that regional variability in diet existed within the Empire.     

Beyond the grave: variability in Neolithic diets in Southern Germany?

Carbon and nitrogen stable isotope analyses were undertaken on human and faunal remains from two Neolithic sites in Southern Germany; the LBK settlement at Herxheim and the middle Neolithic cemetery at Trebur. Stable isotope data were used to reconstruct the diets of individuals buried at these sites and to look at dietary variation between groups classified by their sex, age, grave goods and cultural affiliation. Overall there was surprisingly little variation in the diet between the groups, as described by the stable isotope analysis, despite significant differences in the composition of grave goods. Also surprising, considering the archaeological evidence for extensive grain cultivation in this region during the Neolithic, was that the majority of individuals had δ¹⁵N values consistent with the consumption of significant amounts of animal protein.     

Stable carbon and nitrogen isotope variations in tooth dentine serial sections from Wharram Percy

Here we report δ¹³C and δ¹⁵N measurements of serial sections of human deciduous and permanent tooth dentine from archaeological samples taken from the medieval village site of Wharram Percy, Yorkshire, UK. We found a pattern of enrichment, for both δ¹³C and δ¹⁵N, where the tooth crown was greater than the cervical part of the root, which in turn was greater than the apical portion of the root and the associated rib collagen values. This pattern reflects a decrease in the consumption of isotopically enriched breast milk and the introduction of less enriched weaning foods in the diet. The (mean±SD) difference between the deciduous second molar crowns and corresponding rib samples from the same individuals after 2 years of age was 1.2±0.4‰ for δ¹³C and 3.2±0.8‰ for δ¹⁵N. The δ¹⁵N values are as predicted, but as there were no C₄plants at Wharram Percy, this 1.2‰ enrichment in δ¹³C represents clear evidence of a carbon trophic level effect in collagen from breastfeeding infants. Carbon and nitrogen results also show that the infant diet among those who died in infancy did not differ from those who survived into childhood. This study demonstrates the promise of using dentine serial sections to study the temporal relationships of breastfeeding, weaning, and dietary patterns of single individuals.     

The distinction between freshwater- and terrestrial-based diets: methodological concerns and archaeological applications of sulphur stable isotope analysis

Sulphur isotopes in archaeological bone collagen are not routinely analysed in palaeodietary studies. Here we investigate the potential contribution that sulphur isotope analysis can provide toward the study of ancient human diet and economy, with particular emphasis on the distinction between freshwater and terrestrial consumers. For material from the Late Bronze Age site of Chicha in the south-western Eurasian forest-steppe, sulphur isotopes effectively separate freshwater and terrestrial animal food resources. The sulphur isotope data coupled with nitrogen isotope values from Chicha reflect a dietary reliance upon freshwater animal protein (fish) for the Late Bronze Age inhabitants. In contrast, sulphur isotope values for freshwater and terrestrial potential food species from the Eneolithic site of Bil'shivtsi in western Ukraine were indistinguishable, demonstrating that δ³⁴S values cannot always be relied upon to identify freshwater and terrestrial consumers. The data from this study support the adoption of δ³⁴S analysis as a standard component of palaeodietary studies; apart from its potential to distinguish freshwater from terrestrial consumers, it can provide supplementary dietary information not evident from the carbon and nitrogen isotope data. In addition, certain indices are considered that may be used to assess the validity of sulphur isotope data, as currently exist for carbon and nitrogen. According to the analysis of modern collagen samples, N:S appears to be a broad indicator of collagen sulphur isotope quality. However, more work needs to be done to establish an effective means by which highly-altered sulphur isotope values can be identified and thereby removed from consideration.     

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.     

Stable isotope evidence of human diet at the Nukdo shell midden site,South Korea

Carbon and nitrogen stable isotope analysis was undertaken on bone collagen extracted from archaeological human (n = 48) and animal (n = 45) skeletons from the Nukdo site, Location I C, South Korea. This shell midden and grave site is dated from the late Mumun (550–300 BC) to early Iron Age (300 BC-1 AD) periods. The herbivorous mammals fell within the range of C₃ consumers, with average values of δ¹³C = −21.0 ± 0.5‰ and δ¹⁵N = 3.6 ± 0.5‰ for deer (n = 16) and δ¹³C = −20.6 ± 0.5‰ and δ¹⁵N = 4.5 ± 2.0‰ for wild boar (n = 17). Humans from this site averaged δ¹³C = −18.3 ± 0.4‰ and δ¹⁵N = 11.2 ± 0.7‰ for adults (n = 15) and δ¹³C = −18.7 ± 0.7‰ and δ¹⁵N = 12.5 ± 1.1‰ for juveniles (n = 33). These δ¹³C values indicate that there was no significant input of C₄ plants in the human diets and this may be associated with the spread of rice agriculture in the Mumun period. Human bone collagen δ¹³C and δ¹⁵N values indicate that there was some consumption of marine foods, although the main protein sources were from terrestrial foods. The isotope data demonstrate that the humans at Nukdo had mixed diets that included marine and terrestrial protein, including C₃ plants such as rice. Finally, the isotope results from the juveniles indicate that weaning occurred before the age of 1.5 years in this period.     

The effect of parity status on δN: looking for the “pregnancy effect” in 18th and 19th century London

This study examined the effect of parity status on δ¹⁵N using the well-characterised 18th and 19th century skeletal collection from the crypt of Christ Church, Spitalfields, London. We tested whether the cumulative effect of multiple pregnancies and breastfeeding could significantly reduce female δ¹⁵N values compared to males. The results from stable isotope analysis of 92 adult ribs show that the population of Spitalfields had relatively little variation in diet, compared to contemporary urban populations, and had abundant animal and marine protein. We were able to rule out any effect attributable to socio-economic status, date or age at death on the stable isotope ratios. There were no significant differences in δ¹⁵N due to parity status, nor were there any differences between males and females. Models of collagen turnover rates in ribs suggest that the effect of δ¹⁵N depletion due to pregnancy would be undetectable except in ideal circumstances, where bone of the optimal turnover period was sampled, and in cases where multi-parous individuals died shortly after parturition.     

Stable carbon and nitrogen isotopes of human dental calculus: a potentially new non-destructive proxy for paleodietary analysis

Fifty-eight dental calculus samples from medieval and post-medieval skeletons from Vitoria, Spain, and a single sample from an Alaskan Inuit were tested for stable carbon and nitrogen isotope compositions. There was sufficient carbon and nitrogen concentrations to obtain δ¹³C and δ¹⁵N values, and the samples from Spain produced results that were replicable and comparable to European isotope values based on bone collagen collected from literature sources. The Alaskan Inuit calculus sample yielded a δ¹⁵N value of +17.5‰, well beyond the range of the Spanish samples, but consistent with literature data for modern Greenlandic Inuit consuming a diet rich in marine food. There are several potential sources for carbon and nitrogen in calculus. The results of this study yield stable isotope values consistent with those obtained from other biomaterials used as isotope proxies for paleodietary research, including bone collagen, hair, and fingernails, although further work is necessary to verify the fidelity of calculus as an isotope proxy. Many studies in bioarchaeology are precluded by curatorial concerns regarding the destructive analysis of primary biomaterials. However, calculus is an “add-on”, or secondary biomaterial, that is not an integral part of the dental or skeletal system. Hence, its consumption during analysis is technically not destructive. Therefore, isotope analysis of dental calculus may provide a potential new avenue for paleodietary analysis where the use of other primary biomaterials is precluded.     

Stable isotopic analysis of human and faunal remains from the Incipient Chulmun (Neolithic) shell midden site of Ando Island,Korea

We analyzed stable carbon and nitrogen isotope ratios of human and animal remains from the Ando shell midden, South Korea. The Ando site is a rare Incipient Chulmun (Neolithic) site (ca. 6000–5000 BC), which contains well-preserved human and animal bones in shell mounds. The stable isotope results for humans (average δ¹³C = −13.5 ± 0.5‰ and δ¹⁵N = 15.2 ± 0.5‰) indicate that Ando people in the Incipient Chulmun period strongly depended on marine resources. There were no isotopic differences between humans of different sex and age at this site. We compared our data with other previous published isotopic data from the Chulmun sites and found that the Ando people had similar isotope values to the southern Chulmun people (Tongsamdong and Daepo), but different isotopic ratios than the western Chulmun people (Daejukri and Konamri). These results indicate that marine foods were the main food resources in the southern coastal regions, but not in the western coastal regions in Chulmun Korea.     

A palaeodietary investigation of carbon (C/C) and nitrogen (N/N) in human and faunal bones from the Copper Age cemeteries of Varna I and Durankulak,Bulgaria

Stable isotope analyses have been applied to human and faunal bone collagen from the Varna I and Durankulak cemeteries to explore palaeodietary adaptations in the Neolithic and Eneolithic (Copper Age). The results suggest both populations primarily utilised terrestrial, C₃-based diets, despite their proximity to the Black Sea. The wider δ¹⁵N range of the Durankulak humans likely indicates the differential utilisation of terrestrial meat sources, which is probably related to the degree to which primary and/or secondary ovicaprid products were consumed, particularly since ovicaprid δ¹⁵N values differ from other herbivores. The isotopic distribution of Varna I reflects a linear relationship between δ¹⁵N and δ¹³C, suggesting that a minority of individuals enriched in both isotopic parameters supplemented their diets with marine resources. These burials include the well known ‘chieftain’ (burial 43) and show notable material wealth by way of grave goods. At the population level, however, there is no significant correlation between stable isotope values and material wealth at Varna I, a fact with implications for theories regarding emergent social/economic hierarchies in Balkan prehistory. Five burials at Durankulak were found to have relatively enriched δ¹³C and δ¹⁵N values with respect to the rest of the population. These burials reflect a prominently marine-based or mixed terrestrial C₃-based diet that included C₄ inputs, possibly from millet, for which the limitations of stable isotope analysis on bulk collagen are not able to differentiate. AMS dating has shown that these burials belong to a much later period.     

Stable carbon and nitrogen isotope analysis on human remains from the Early Mesolithic site of La Vergne (Charente-Maritime,France)

We report here the results of stable carbon and nitrogen isotope analysis of human and faunal remains from La Vergne (Charente-Maritime, western France), a rare Early Mesolithic burial site (ca. 8500–8000 cal BC). The results for nine humans (average δ¹³C = −19.3‰; δ¹⁵N = 9.4‰) indicate a strongly terrestrial diet, dominated by animal protein, with the possibility of, at best, a slight contribution of marine-derived protein. Given lower sea-levels in the early Holocene, the site would have been some 60–80 km from the sea at the time of its use; nevertheless, contacts with the coast are shown by the presence of numerous marine shell beads in the graves. In the light of the stable isotope results, it is suggested here that such contacts most likely took the form of exchange with coastal communities whose remains now lie underwater.     

Stable isotope analysis of humans from Xiaojingshan site: implications for understanding the origin of millet agriculture in China

Millet agriculture originated in Northern China in the early Neolithic period (ca. 8000 BP), however, the actual importance of millet in human diets is still not clear. To determine the relative contribution of millet in human diets in this period we undertook stable isotope analysis of humans from Xiaojingshan site and fauna from Yuezhuang site, both of which are attributed to the Houli Culture and date to about 8000 years ago. The carbon isotope values of human bone collagen showed that millet (as a C₄ plant) only contributed approximately 25% of dietary protein, with the rest from C₃ based plant and animal sources, if a simple mixing model is used. We did not observe any statistical dietary difference between males and females at the site, although it has been argued that the Houli Culture was a matriarchal society. Finally, we compared our data with other published isotopic data from the contemporary Jiahu site and Xinglongwa site and a number of sites from the subsequent Yangshao Culture and found that millet only became a significant source of dietary protein approximately 1000 years later, as human carbon isotope values from these later sites indicated that almost all of dietary protein came from C₄ (i.e. millet) sources.     

The fish of Lake Titicaca: implications for archaeology and changing ecology through stable isotope analysis

Research on past human diets in the southern Lake Titicaca Basin has directed us to investigate the carbon and nitrogen stable isotopes of an important dietary element, fish. By completing a range of analyses on modern and archaeological fish remains, we contribute to two related issues regarding the application of stable isotope analysis of archaeological fish remains and in turn their place within human diet. The first issue is the potential carbon and nitrogen isotope values of prehistoric fish (and how these would impact human dietary isotopic data), and the second is the observed changes in the fish isotopes through time. Out of this work we provide quantitative isotope relationships between fish tissues with and without lipid extraction, and a qualitative analysis of the isotopic relationships between fish tissues, allowing archaeologists to understand these relationships and how these values can be applied in future research. We test a mathematical lipid normalization equation to examine whether future researchers will need to perform lipid extraction procedures for Lake Titicaca fish. We also analyze a number of aquatic plants to better understand the range of isotopic signatures of the Lake Titicaca ecosystem. We use these data to better understand prehistoric human diet and the role that fish may have played in the past as well as potential changes in local lake ecology through time.     

Endangered species,archaeology, and stable isotopes: huemul (Hippocamelus bisulcus) isotopic ecology in central-western Patagonia (South America)

The management and conservation of animal species should be based upon a long-term analysis that considers its geographical distribution and feeding patterns. The study of carbon and nitrogen stable isotopes on skeletal remains provides a quantitative approach to the paleodietary reconstructions and constitutes a potent tool for comparing behavioral aspects of the fauna. In this paper we present the first set of isotopic values for modern and archaeological samples of Huemul (Hippocamelus bisulcus) from the forests of Central-western Patagonia, Chile. Contrary to initial expectations, our analysis indicates that there is no evidence of an important incidence of the canopy effect on the δ¹³Ccollagen values, which we suggest is due to an ecological selection that drives the huemul to focus its predation on open sectors within the forest. On the other hand, a wide range of δ¹⁵Ncollagen values for huemul was verified. This could reflect the N impoverishment of the forest soils and provide an interesting ecological indicator. The long-term information offered by the archaeological record provides the necessary context for decision-making conducive towards the preservation of Hippocamelus bisulcus in Patagonia.     

Determining the provenance of black limestone artifacts using petrography,isotopes and EPR techniques: the case of the monument of Bocco

This paper investigates the provenance of the black limestone of the monument known as Bocco, named after the king of Mauretania who presented Silla with this work as a sign of his submission to the power of Rome. A multi-method approach, comprising petrographic observations, carbon and oxygen isotope composition and electron paramagnetic resonance (EPR) spectra characteristics, was used for this purpose. The monument is part of a reconstruction of a rectangular base (approx. 8 × 2 m) which is likely to have served as the base for a bronze statuary group and is currently composed of six blocks of limestone whose exterior is engraved with a fine frieze. The results of the different analyses were compared with the data of a published database of the most important black limestone quarries exploited during Roman times in the Mediterranean area. The petrographic and physico-chemical parameters did not prove to be very effective in determining the provenance of the black limestone of Bocco; the isotopes result even raised some uncertainty as to whether all six blocks came from the same quarry, though this doubt was dispelled by the EPR data and, above all, by the evident petrographic similarity between them. Differences in the isotopic composition of the various blocks may be due to an in situ rock alteration process caused by interaction with an aqueous fluid. It was, however, impossible to determine with certainty the origin of the material of the stone artifact using the database available; it is possible that the black limestone of Bocco came from an ancient quarry that is likely to be located in north western Africa but has not yet been uncovered. An alternative hypothesis, according to which the limestone used for the monument of Bocco came from the ancient quarry of Ain el Ksir, one of the Tunisian quarries present in the database, is also discussed.     

Stable isotopes and human diet in central western Argentina

Central western Argentina is the southern boundary of prehispanic maize in the archaeological record. This paper explores the stable isotope information from human bone (δ¹³C, from collagen and δ¹³C from apatite) and tooth (δ¹³C from enamel) samples in order to characterize the temporal and spatial trends of these isotopes and to understand them in terms of human diet. We analyzed 104 human individuals from the last 6000 years. Using the Kellner and Schoeninger (2007) model the results shows a high variation in human diet with few human individuals with a notably high significance of C₄ plants (probably maize) as an energy source and these samples have a chronology around ca. 1000 years BP. On the other hand a high variation in an individual’s dietary life history is shown by differences between δ¹³C collagen, apatite and enamel.     

A Late Holocene vertebrate food web from southern Haida Gwaii (Queen Charlotte Islands, British Columbia)

This study presents isotopic data (δ¹³C and δ¹⁵N from bone collagen) for 104 samples representing 29 vertebrate taxa from late pre-contact through to contact era (ca. 2000 – 100 BP) Haida Gwaii (British Columbia, Canada) from a wide variety of mostly marine organisms. The results demonstrate the considerable isotopic variability that characterizes potential prey items in coastal contexts and underscores the need for baseline faunal data to interpret human subsistence practices. Based on these data, a detailed marine food web was constructed, which provides insight into local ecological conditions. We present a simple method for quantifying the trophic level of ancient fauna using δ¹⁵N of bone collagen. Finally, we discuss the implications of this study for the reconstruction of human diet.