Paleodiet in northern Chile through the Holocene: extremely heavy δN values in dental calculus suggest a guano-derived signature?

Dental calculus extracted from the teeth of 28 prehistoric human skeletons from coastal and valley archaeological sites in northern Chile that date from the Archaic period (∼2300 BC) to the Late Intermediate period (AD 1476) was analyzed for stable isotope (δ¹⁵N, δ¹³C) compositions. δ¹⁵N compositions were extremely heavy (+17.8 to +33.1‰), but comparable to some studies using conventional human biomaterials (hair, nail, muscle) at other prehistoric sites in northern Chile. There was a negative correlation between δ¹⁵N and δ¹³C for coastal sites, but a positive correlation for valley sites. Results for the valley sites point to a diet that was influenced by marine resources throughout all time periods. The unusually heavy δ¹⁵N values for the coastal sites require a dietary component with a δ¹⁵N composition significantly heavier than that of marine resources. The hyper-aridity at the study area (mean annual rainfall of 0.5–0.6 mm/year) is a likely contributing factor to the production of heavy δ¹⁵N values, but is unlikely to account for the heaviest δ¹⁵N values (>+30‰). One possible explanation for the heaviest δ¹⁵N values is that dietary components were impacted by isotopically-heavy guano, which is abundant in the region. Guano may have been used as a fertilizer during crop cultivation at the onset of the Formative period, continuing through the Historic period after Spanish contact. The indirect impact of guano from abundant bird habitats in the region may have influenced wild foodstuffs harvested throughout the pre-agricultural period. Results provide support for the utility of dental calculus as a proxy for obtaining stable carbon and nitrogen isotope signatures for use in paleodietary studies.     

Stable Isotopes and Oral Tori in Greenlandic Norse and Inuit

Palatine (PT) and mandibular torus (MT) have long been of interest to dental researchers and anthropologists, but their aetiology remains unresolved. Some combination of genetic and environmental factors influences their expression, but the relative role of each remains contentious. Previous research has shown that the Greenlandic Norse exhibit exceptionally high frequencies and pronounced expressions of PT and MT. In this regard, they are significantly different from genetically related medieval Scandinavian populations, so environmental factors have to be considered. An earlier study that estimated stable carbon and nitrogen isotope compositions for a Greenlandic Norse sample makes it possible to compare directly PT and MT expression with the relative degree of marine protein intake. For comparative purposes, parallel observations were made on a Greenlandic Inuit sample. Some researchers suggest the intake of marine resources could impact bone development, including torus expression, but our analysis found no significant correlation between PT or MT expression and δ¹³C and δ¹⁵N values in the Norse. In the Inuit, PT expression also showed no relationship to stable isotope compositions. MT size in the Inuit did, however, show a significant inverse relationship with δ¹³C and δ¹⁵N values. As MT size goes up, stable isotope compositions go down. Compared with contemporary European populations, the Greenlandic Norse show very positive isotope compositions, but the Inuit, with their high protein‐high fat diet, show significantly higher δ¹³C and δ¹⁵N values than the Norse. It is unclear how this relates to the contrasting findings for MT size and stable isotope values. Copyright © 2016 John Wiley & Sons, Ltd.     

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 isotope analysis of Pacific rat (Rattus exulans) from archaeological sites in Mangareva (French Polynesia): The use of commensal species for understanding human activity and ecosystem change

Stable carbon and nitrogen isotope analysis was applied to archaeological specimens of the commensal Pacific rat (Rattus exulans) to investigate nutrient fluxes in prehistoric socio-ecosystems on Mangareva (Gambier Islands) and their implications for anthropogenic environmental change. The Pacific rat – ubiquitous in Polynesian archaeological sites – is characterised by low dietary selectivity and a limited home range, making it an ideal candidate for assessing changes in island food webs. Temporal trends in diet-derived bone collagen δ¹³C and δ¹⁵N values are assessed from three sites: The Onemea Site, Taravai Island (TAR-6), Nenega-iti Rockshelter, Agakauitai Island (AGA-3) and Kitchen Cave Rockshelter, Kamaka Island (KAM-1). An overall trend of decreasing δ¹⁵N values in rat bone collagen over time reflects archipelago-wide changes to island socio-ecosystems most likely resulting from seabird population declines. Differences in site function and human activity may have also influenced local rat dietary patterns. Stable isotope analysis of the Pacific rat provides a low-impact line of evidence towards the reconstruction of human-centred food webs and the flow of nutrients within island socio-ecosystems.     

Stable isotopic analysis of human bones from Jiahu site,Henan, China: implications for the transition to agriculture

We have investigated change in subsistence during the transition to agriculture in the site of Jiahu, Henan Province, China, using stable isotopic analysis of collagen and apatite in human bones. Millet agriculture is well documented at drier high latitudes of the Yellow River Valley, while rice agriculture predominated at wetter lower latitudes of the Yangtze Valley region. The early Neolithic site of Jiahu lies near the boundary between the drier north and wetter south. Archaeobotanical evidence shows that rice was a significant component of diet at Jiahu, but its δ¹³C value is similar to that of other foods, and therefore cannot be conclusively identified by carbon isotope analysis. Foxtail and broomcorn millets are the only C₄ crops known for the Chinese Neolithic. Because of their high δ¹³C values, their consumption can be evaluated by stable carbon isotope analysis of human bone. Collagen reflects mainly the δ¹³C value of dietary protein, and apatite accurately records that of the whole diet. Isotopic analysis of 15 well-preserved samples from three periods shows that collagen δ¹³C values were very low for almost all individuals, suggesting C₃-based foods dominated their diets. However, apatite carbonate δ¹³C values and δ¹³C spacing between collagen and apatite (Δ¹³C_ap-co) indicate that millet may have been a minor component of the diet in this region. Individuals, who consumed the smallest amounts of animal protein, as indicated by low δ¹⁵N, generally had the highest apatite δ¹³C values. Archaeobotanical evidence for millet at Jiahu is needed to support this interpretation.     

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.     

Introducing δSr analysis in archaeology: a demonstration of the utility of strontium isotope fractionation in paleodietary studies

Isotopic methods are widely used in archaeology to investigate paleodiet. Here, we present a new method to identify trophic level in archaeological human populations and to investigate paleodiet. We demonstrate that strontium isotope compositions (reported as δ^88/86Sr) vary in a mass-dependent manner with increasing trophic level and can elucidate paleodiet in archaeological human populations. We present new mass-dependent strontium isotope data from tooth enamel and bone from individuals buried during the Late Intermediate Period (c. AD 1000–1300) in the large cemeteries of Chiribaya Alta, Chiribaya Baja, San Gerónimo, and El Yaral in the Ilo and Moquegua Valleys of southern Peru. We compare these data to radiogenic strontium isotope data (⁸⁷Sr/⁸⁶Sr) and light stable isotope data (δ¹⁵N_col and δ¹³C_col) from the same individuals to investigate geologic variability in strontium sources as well as marine food consumption among the Chiribaya. Our results demonstrate the utility of measurements of strontium isotope fractionation as a new tool for archaeological investigation of paleodiet. Importantly, this new technique can be used to generate paleodietary (δ^88/86Sr) and paleomobility (⁸⁷Sr/⁸⁶Sr) data from the same specimen, minimizing destructive analyses of invaluable archaeological material, and provides a new way to examine paleodiet through hydroxyapatite, which is particularly important when collagen is poorly preserved.     

Distinguishing sheep and goats using dental morphology and stable carbon isotopes in C4 grassland environments

Distinguishing between sheep and goats in C₄ grass environments using new dental morphology criteria and enamel bioapatite stable carbon isotope ratios (δ¹³C) was tested on 35 modern individuals from the Central Rift Valley of Kenya. Two morphological criteria on the second and third lower molars, one of which had been previously partially described by Halstead et al. [Journal of Archaeological Science 29 (2002) 545], were found to be highly reliable in this population. Identification of species using carbon isotope ratios is made possible in some circumstances by differences in the feeding behavior of sheep, which are mainly grazers, and goats, which are mainly browsers. In environments where C₄ grasses predominate, sheep include a higher proportion of C₄ plants in their diet, and thus have higher δ¹³C values than goats. In the present study, the annual range and seasonal variation of carbon isotope ratio of diet of sheep and goats was measured from intra-tooth sequential analysis. Although the ranges of goat and sheep δ¹³C values overlap, those higher than −3.4‰ all belong to sheep; values lower than −5.2‰ all belong to goats. There is no overlap of the mean δ¹³C values by tooth, which range from −11.8‰ to −4.2‰ for goats, and from −3.1‰ to −1.3‰ for sheep. These results suggest that carbon isotope analysis of bone collagen and/or apatite will also distinguish sheep from goats in tropical C₄ grasslands. Application of the δ¹³C criteria to archaeological material must be restricted to C₄-dominated environments, and where potential access to C₃ plants (mobility, foddering) can be assessed. The utility of these morphological and isotopic criteria for differentiating sheep and goat breeds in other regions remains to be evaluated.     

Evaluating bone collagen extraction methods for stable isotope analysis in dietary studies

The specific purpose of this study was to compare three different collagen extraction methods commonly used in isotope laboratories conducting dietary studies. We evaluated their resultant differences in δ¹³C and δ¹⁵N, collagen quality and collagen yield. Our study was based on well-preserved skeletal material from the medieval period in Denmark. Our study shows that there is a systematic significant difference in the yield and the δ¹³C values between the three methods. Using the method of DeNiro and Epstein [DeNiro, M.J., Epstein, S., 1981. Influence of diet on the distribution of nitrogen isotopes in animals. Geochimica et Cosmochimica Acta 45, 341–351] with NaOH as cleaning agent, will, according to our study, give δ¹³C values that are on average ±0.32‰ more positive than using the ultra-filtration method [Brown, T.A., Nelson, D.E., Vogel, J.S., Southon, J.R., 1988. Improved collagen extraction by modified Longin method. Radiocarbon 30 (2), 171–177, modified in Richards, M.P., Hedges R.E.M., 1999. Stable isotope evidence for similarities in the types of marine foods used by late Mesolithic humans at sites along the Atlantic coast of Europe. Journal of Archaeological Science 26, 717–722]. The third method, which is a modified version of the second method, excluded the ultra-filtration step. This method seems to give δ¹³C values that lie in between the other methods. Our study did not show any significant difference in δ¹⁵N values. Although the differences between the methods are very small, we conclude that the use of stable isotope analysis in food determination studies requires adherence to routine methods for preparing and measuring samples.     

Isotopic palaeodiet studies of Ancient Egyptian fauna and humans

We report here stable carbon and nitrogen isotope results from human and faunal bone collagen from samples taken from sites in the Egyptian Nile Valley and surrounding region, dating from the Predynastic (c. 5500 BC) through to the Dynastic (c. 343 BC) periods. Isotopic values for the human population cluster together across this broad time range, with high δ¹⁵N ratios, and δ¹³C values indicating a largely C₃ based diet. The human data is not easily explained through comparison with our associated faunal data, and so may be explained by the consumption of protein from an ecosystem we did not adequately sample, such as freshwater fish or plants and fauna with unusually high δ¹⁵N values due to the extreme aridity of this region. The faunal isotopic data we did produce shows a great range in values between and within species, especially in cattle, and reflects the close proximity of three ecozones across a relatively narrow geographical area; the river, the immediate flood-plain area around the Nile and the desert surroundings.     

Stable Carbon and Oxygen Isotope Spacing Between Bone and Tooth Collagen and Hydroxyapatite in Human Archaeological Remains

Spacing between stable isotope values in bones and teeth is a valuable tool for examining dietary influences and diagenesis. This study examines carbon and oxygen isotope values from collagen and hydroxyapatite (structural carbonate and phosphate) in archaeological human bones and teeth to derive species‐specific correlation equations and isotope spacing values. The δ¹³C_collagen and δ¹³C_{structural carbonate} in bone and dentin collagen show a strong correlation (R = 0.87, 0.90, respectively) with an average Δ¹³C_carb‐coll spacing of 5.4‰. The consistency of this isotope spacing with other large mammals and in humans with both low and high protein intake (as indicated by enriched δ¹⁵N values) suggests a similar allocation of protein‐derived carbon and whole diet‐derived carbon to collagen and structural carbonates, respectively, as other terrestrial mammals regardless of absolute meat intake. The δ¹⁸O_{structural carbonate} and δ¹⁸O_phosphate show the strongest correlation in enamel (R = 0.65), weaker correlations in dentin (R = 0.59) and bone (R = 0.35), with an average Δ¹⁸O_carb‐phos of 7.8‰. This isotope spacing is slightly lower than previously reported for large mammals and limited available data for humans. The results potentially indicate species‐specific fractionations and differing access to body water and blood‐dissolved inorganic carbonates in the presence of collagen formation. The use of correlation between δ¹⁸O_{structural carbonate} and δ¹⁸O_phosphate to determine diagenetic state is not recommended. The strength of this correlation observed in bones and teeth is variable and alternate indicators of diagenetic state (i.e. C:N ratios of collagen) provide more robust and independent evidence of isotope preservation despite presence/absence of a strong isotope correlation. Published 2012. This article is a U.S. Government work and is in the public domain in the USA.     

BIOARCHAEOLOGICAL ANALYSIS OF SUBSISTENCE AND HEALTH AT THE LAKE GEORGE SITE,MISSISSIPPI (22YZ557)

Abstract

Bioarchaeological investigations of subsistence and health were conducted on a skeletal population from the Lake George site (22YZ557), a large prehistoric settlement in the lower Yazoo basin of west-central Mississippi. Subsistence is inferred from oral health indicators (including dental caries, calculus, periodontal disease, abscesses, antemortem tooth loss, and macrowear) and stable carbon and nitrogen isotope ratios from bone collagen and apatite. Health is inferred from nonspecific indicators (including cranial porous lesions, enamel hypoplasias, and Harris lines). The sample includes 25 adults and 25 subadults, all of which date to the Coles Creek period (A.D. 700–1200). Frequencies of all pathological conditions are reported for the entire sample and divided by sex and age for adults. Results indicate a heavy pathology load at Lake George, but one that is not dissimilar to other Coles Creek populations. Isotope values indicate a diet that included primarily C3 plants (δ¹³C_Col = ?21.03‰, δ¹³C_Ap-Diet = ?22.06) and terrestrial protein (δ¹⁵N = 9.72‰). The sources of nonspecific pathologies are attributed to stressors associated with increasing population density and cultural complexity that occurred during the Coles Creek period.     

Let them eat cake? Status-based differences in diet in medieval Denmark

The goal of this research is to explore status-based differences in diet of the peasants, monks and elites interred at the medieval Cistercian monastery of Øm Kloster. In order to accomplish this task bone samples were taken from 98 individuals from the monastery for the stable isotopic analysis of carbon and nitrogen found in both bone collagen and apatite. Significant differences were found in the diet of these three groups. Elites demonstrated significantly enriched δ¹⁵N and δ¹³C values and had the smallest δ¹³C_coll-ap spacing in comparison to the peasant and monastic population. Although there were no changes in the diet of the elite or peasant population through time, the monastic diet shifted from resembling the diet of the peasant population early in the period to more closely matching that of the elites at the close of the period, although small sample size precluded the significance testing of this shift. This research suggests that social status played a considerable role in the types and quantity of food resources available to a given individual in society and that there were some socially based differences in the medieval Danish diet.     

The Ba/Sr ratio,carious lesions,and dental calculus among the population buried in the church La Concepción (Tenerife,Canary Islands)

Certain trace elements may accumulate in bone in relation to dietary habits, so some of them are of interest in paleodietary analysis. This is the case with strontium (Sr) and barium (Ba), whose potential value as paleodietary indicators is enhanced by their relatively inert metabolic behaviour. The presence of carious lesions may indicate consumption of sugar and vegetables, whereas the etiology of dental calculus deposition is multifactorial, although some authors consider this as an indicator of protein consumption. Based on these facts we analysed (1) Ba, Sr, and calcium (Ca) content of inner cortical bone obtained from the ramus mandibularis, by atomic absorption spectrophotometry, (2) presence of teeth with carious lesions, and (3) presence of teeth with calculus deposition in 62 mandibles. All samples were obtained from the church La Concepción, an 18th century burial place in Tenerife. Gender was assessed by analysing genetic expression of amelogenin in some cases (14), and by inspection of pelvic bones when available (41 cases). We found (1) Carious lesions in 32 cases, and dental calculus, in 39; no association was observed between sex and presence of dental caries or calculus deposition, nor between the sex and the proportion of carious teeth nor the proportion of teeth with calculus deposition; (2) people buried near the altar (priests and individuals of the highest social class) showed a significantly higher proportion of teeth with dental calculus deposition (χ² = 5.36, p = 0.021); (3) bone Sr and bone Ba were significantly higher than the values observed in a control group of 10 modern omnivorous individuals; the lowest Sr values were observed among people buried near the altar; and (4) the Ba/Sr ratio was directly related with the proportion of teeth with carious lesions. These data suggest that there were differences in dietary pattern among the individuals belonging to different social classes; overall, consumption of vegetables was widespread, as shown by the high proportion of carious lesions, in relation with raised Ba/Sr ratio, whereas consumption of marine products was scarce.     

Dietary adaptation during the Longshan period in China: stable isotope analyses at Liangchengzhen (southeastern Shandong)

Rice and millet were staple crops at Liangchengzhen, a late Neolithic Longshan site in Shandong, China, but the degree of dietary variation is not known. This study uses stable isotope analysis of human and faunal skeletal remains to quantitatively address the importance of these crops as well as terrestrial domesticates and aquatic resources in the diet at Liangchengzhen. Although no collagen could be extracted from the poorly preserved human bones, the δ¹³C stable isotope results for 2 apatite sample and 16 tooth enamel samples averaged −9.8‰ suggesting that diet was based on foods averaging from −24‰ to −18‰, with millet and millet-fed animals comprising at most approximately 25–30% of the diet. Pig faunal δ¹³C isotope values suggested that during the earlier Longshan period pigs were fed mainly millet with more C₃ foods such as rice included by the later Longshan period. Solid ceramic residues from two guan jar sherds produced δ¹³C values averaging −18‰ and δ¹⁵N values averaging +16‰, suggesting both vessels contained fish. The results of the study indicate that by the Longshan period, people in southeastern Shandong no longer relied as heavily on millet and that the agricultural crop of rice had increased in importance at Liangchengzhen. Unfortunately, without human collagen samples to provide nitrogen isotope results, we cannot estimate the relative contribution of aquatic and terrestrial protein to the diet of people at Liangchengzhen. In general, however, the pattern of a diverse agricultural system on the basis of the macrobotanical remains from Liangchengzhen is supported by the isotopic results.     

FOCUS: effect of diet and protein source on carbon stable isotope ratios in collagen: follow up to

We analyzed carbon stable isotope data from bone collagen of animals consuming varied experimental diets, including recently published data from Warinner and Tuross [Warinner, C., Tuross, N., 2009. Alkaline cooking and stable isotope tissue–diet spacing in swine: archaeological implications. Journal of Archaeological Science 36, 1690–1697; this journal]. Comparing regression lines for the relationship between collagen and diet δ¹³C, we show that protein source, and not physiology, explains the apparent taxonomic difference between swine and rodents reported in that paper. Our results reveal a complex relationship between whole diet and dietary protein in determining collagen δ¹³C values, such that in many cases, collagen alone may not provide reliable reconstructions of paleodiet. We advocate the simultaneous use of both collagen and apatite δ¹³C, whenever possible, to assess the diets of prehistoric peoples.     

Stable isotope investigations of charred barley (Hordeum vulgare) and wheat (Triticum spelta) grains from Danebury Hillfort: implications for palaeodietary reconstructions

Palaeodietary studies typically focus on the analysis of bone collagen due to the limited availability of plant remains. Isotopic analysis of plant remains, however, allow for a more extensive consideration of the contribution of plants to the human diet and can potentially provide information about the environment in which the crops were grown. This paper reports the results of carbon and nitrogen isotope analyses performed on charred barley and wheat grains recovered from pits within Danebury Iron Age hillfort. To the best of our knowledge, this is the first Iron Age site in Britain from which charred grains have been isotopically analysed. Our results suggest that cereals found at the hillfort were grown in several different environmental contexts. The isotope data demonstrate that the herbivores were not consuming a diet primarily based on grains as the δ¹⁵N values of the grains are very similar to those of the herbivores. Palaeodietary investigations typically assume that humans eating plant protein only would have the same δ¹⁵N value as the local herbivores. This assumption is clearly invalid at Danebury, where the humans and animals appear to have consumed either different parts of the same plants or different plants. Researchers typically interpret high differences between human and animal δ¹⁵N values as indicative of diets high in animal protein, however where major plant resources have δ¹⁵N values similar to those of the herbivores our ability to distinguish between plant and animal sources of protein in the diet is limited. Our research has demonstrated that whenever possible it is desirable to measure the isotopic signatures of potential major plant resources in order to understand past subsistence strategies.     

From Traditional Farming in Morocco to Early Urban Agroecology in Northern Mesopotamia: Combining Present-day Arable Weed Surveys and Crop Isotope Analysis to Reconstruct Past Agrosystems in (Semi-)arid Regions

ABSTRACT

We integrate functional weed ecology with crop stable carbon and nitrogen isotope analysis to assess their combined potential for inferring arable land management practices in (semi-)arid regions from archaeobotanical assemblages. Weed and GIS survey of 60 cereal and pulse fields in Morocco are combined with crop sampling for stable isotope analysis to frame assessment of agricultural labour intensity in terms of manuring, irrigation, tillage and hand-weeding. Under low management intensity weed variation primarily reflects geographical differences, whereas under high management intensity fields in disparate regions have similar weed flora. Manured and irrigated oasis barley fields are clearly discriminated from less intensively manured rain-fed barley terraces in southern Morocco; when fields in northern and southern Morocco are considered together, climatic differences are superimposed on the agronomic intensity gradient. Barley δ¹³C and δ¹⁵N values clearly distinguish among the Moroccan regimes. An integrated approach combines crop isotope values with weed ecological discrimination of low- and high-intensity regimes across multiple studies (in southern Morocco and southern Europe). Analysis of archaeobotanical samples from EBA Tell Brak, Syria suggests that this early city was sustained through extensive (low-intensity, large-scale) cereal farming.     

Aquatic resources in human diet in the Late Mesolithic in Northern France and Luxembourg: insights from carbon,nitrogen and sulphur isotope ratios

We investigated the contribution of freshwater resources to the diet of seven Late Mesolithic hunter-gatherers (ca. 5300–7000 BC) from Northern France and Luxembourg using stable isotope ratios. In addition to the carbon and nitrogen stable isotope ratios (δ¹³C, δ¹⁵N), we explored the potential of the sulphur isotopic ratios (δ³⁴S) to detect and quantify the proportion of protein derived from aquatic foodstuff. In only two sites, animal remains from an associated settlement were available and subsequently examined to decipher the isotopic differential between terrestrial and freshwater resources. The quantification of their relative contribution was simulated using a Bayesian mixing model. The measurements revealed a significant overlap in δ¹³C values between freshwater and terrestrial resources and a large range of δ¹⁵N values for each food category. The δ³⁴S values of the aquatic and terrestrial animals were clearly distinct at the settlement in the Seine valley, while the results on fish from Belgium demonstrated a possible overlap in δ³⁴S values between freshwater and terrestrial resources. Local freshwater ecosystem likely contributed to ca. 30–40 % of the protein in the diet of the individuals found in the Seine settlement. Out of this context, the isotopic signature and thus contribution of the available aquatic foods was difficult to assess. Another potential source of dietary protein is wild boar. Depending on the local context, collagen δ³⁴S values may contribute to better assessment of the relative contribution of freshwater and terrestrial resources.     

New Dietary Evidence on Medieval Rural Communities of the Basque Country (Spain) and Its Surroundings from Carbon and Nitrogen Stable Isotope Analyses: Social Insights,Diachronic Changes and Geographic Comparison

This paper presents the results of palaeodietary reconstruction based on stable carbon and nitrogen isotope analysis on bone collagen of five medieval rural populations from the Basque Country (northern Spain) spanning from 5^th to 15^th centuries ad . One hundred forty‐seven human and 47 domestic faunal samples were successfully analysed with the objective of defining agrarian productive strategies and food consumption patterns. The results grouped the five sites in two clusters: on one side Zaballa and Treviño, whose inhabitants followed diets exclusively based on C₃ plants with significant intake of animal protein, and on the other, the populations from Aistra and Zornoztegi, who combined C₃ and C₄ plants and consumed lower amounts of animal protein. The isotopic values from Dulantzi were intermediate to these two groups. No differences were detected when individual status markers, such as grave goods, were available. Conversely, some restrictions on the access to certain food resources based on sex were uncovered. A relevant change in δ¹³C values was identified around 10^th century, a consequence of a shift in the consumption patterns of C₃ and C₄ plants. Finally, these Basque sites were compared with those of the medieval Iberian case studies available in the literature. This comparison made evident the distinctive nature of the diet of the Basque medieval rural contexts. Copyright © 2017 John Wiley & Sons, Ltd.