Coast–inland mobility and diet in the Danish Mesolithic and Neolithic: evidence from stable isotope values of humans and dogs

Here we present the stable isotope ratios of carbon and nitrogen measured in bone collagen extracted from humans, dogs, herbivores and fish from Mesolithic and Neolithic coastal and inland sites in Denmark. Bones of freshwater fish from several Early Mesolithic lake-side sites have δ¹³C values surprisingly similar to those seen in marine fish. We propose a model, based on δ¹³C and δ¹⁵N, for the correction for both marine and hard water reservoir effect in radiocarbon dates. A strong reliance on aquatic protein is demonstrated for the Mesolithic inhabitants of the region from the middle of the Early Mesolithic onwards. A significant part of the protein in the diets of the dogs and humans from the Middle and Late Mesolithic was of marine origin, even at inland sites. This observation points to a high degree of (seasonal) coast-inland mobility. The isotopic evidence indicates that during the Neolithic small quantities of aquatic foods were still common sources of dietary protein.     

A biometric technique for assessing prehistoric freshwater mussel population dynamics (family: Unionidae) in north Texas

Biometry is useful for a suite of analyses relevant to zooarchaeology, which include analysis of mortality profiles, taphonomy, paleoecology, among other purposes. Here, size-age prediction models are developed for 10 freshwater mussel species found in north Texas to develop a method for studying paleoenvironmental conditions. Shell length is often used to evaluate the structures of modern mussel populations, but its use on paleozoological specimens is not feasible because complete shells rarely preserve. Instead, pallial line-to-lateral teeth length (PLL) and pseudocardinal teeth-to-pallial line length (PSP) are evaluated as proxy measures for shell length. Linear regression models based on PLL and PSP using modern mussels demonstrate that they are accurate proxies of shell length for multiple species from a variety of habitats. In addition, ontogenetic-age structures for a modern sample and for two late Holocene assemblages from north Texas are developed using PLL and PSP. These techniques are useful tools for evaluating past ecological conditions of freshwater mussel populations when large samples are available for study, which expands analytical potential of zooarchaeological studies of prehistoric unionid remains.     

Understanding the variability in freshwater radiocarbon reservoir offsets: a cautionary tale

Freshwater resources in past diets can lead to inaccuracies when attempts are made to ascertain their radiocarbon ages or those of the consumers. Radiocarbon reservoir effects may lead to significant age offsets when the bones or other tissues of these consumers are radiocarbon dated. A number of recent studies have investigated freshwater reservoir offsets. However no study thus far has satisfactorily obtained a ubiquitous freshwater reservoir correction due to variability in the ecosystems analysed. This study tests the possibility of predicting freshwater reservoir effects from the carbonate alkalinity of the water with measurements on modern fish bone and water samples. A predictive capability would be especially valuable in the absence of well-preserved archaeological fish bone. We surveyed samples from lakes and rivers in varying geological settings in Britain and Ireland. Modern fish bone and water samples were analysed to investigate modern radiocarbon offsets from the atmosphere. Archaeological fish bone was also analysed to examine past reservoir offsets at selected sites. Stable carbon and nitrogen isotope values were measured to aid in interpretation of any variability in the offsets. Large freshwater reservoir offsets were measured in some modern and archaeological samples (maximum offset = 1638 ¹⁴C years). The freshwater reservoir offsets in the fish bone were highly correlated with alkalinity of water in modern lake sites analysed. However, a high amount of variation within and between fish species was also evident in the results, precluding the possibility of providing regional corrections for freshwater reservoir offsets from alkalinity although this still may provide a general guideline. The variability is thought to be due to differences in the diet of individual fish.     

Stable isotope dietary analysis of prehistoric populations from the Minusinsk Basin,Southern Siberia,Russia: a new chronological framework for the introduction of millet to the eastern Eurasian steppe

We report the results of stable carbon and nitrogen isotope analysis of 354 human and faunal samples from five archaeological cultures of the Minusinsk Basin, Southern Siberia – Afanasyevo, Okunevo, Andronovo, Karasuk and Tagar (ca. 2700–1 BC) – a key location in Eurasia due to its position on a northern corridor linking China and central Eurasia. The results indicate that the diet of Eneolithic to Middle Bronze Age (Afanasyevo to Andronovo) populations was primarily C₃-based, with C₄ plants only becoming an important component of the diet in the Late Bronze Age Karasuk and Early Iron Age Tagar cultures. Freshwater fish seems to have been an important constituent of the diets in all groups. The findings constitute the earliest concrete evidence for the substantial use of millet in the eastern Eurasian steppe. We propose that it was probably introduced from Northwestern China during the Karasuk culture at the start of the Late Bronze Age, ca. 1500 BC. We conclude with a discussion of the implications for the nature of pastoralist economies on the steppes.     

Carbon and nitrogen isotope signals in eel bone collagen from Mesolithic and Neolithic sites in northern Europe

Carbon and nitrogen isotope analysis was undertaken on collagen extracted from eel bone from six Mesolithic and Neolithic sites in northern Europe. The results were compared with data obtained on other archaeological fish remains and modern eel caught in fresh and brackish water and from the sea. The possibility of discriminating between freshwater, brackish and marine signals in archaeological eel bone is evaluated and the implications for archaeology discussed. Our data suggest that eel found at coastal Mesolithic and Neolithic sites have carbon isotope signals consistent with a marine origin with no evidence of freshwater residency. The sample of eel bone from one inland site is small but indicates carbon isotope values more consistent with freshwater residency or at least values intermediate between freshwater and marine carbon pools.     

A comparison of multiple proxy data sets for paleoenvironmental conditions as derived from freshwater bivalve (Unionid) shell

Freshwater mussel shells from Middle and Late Holocene strata at an archaeological site in Mississippi, U.S.A., are examined for morphological and chemical differences that could be related to changing paleoenvironmental conditions. Although significant differences are noted, the different data sets provide contradictory or unclear results, suggesting that reliance upon single data sets is an unwarranted practice.     

A conceptual model for freshwater mussel (family: Unionidae) remain preservation in zooarchaeological assemblages

Expectations for survival of vertebrate remains have been well developed and intensely studied in the zooarchaeological taphonomic literature. Taphonomic studies of shellfish remains focus on marine species and on variables relevant to remains from paleontological contexts (e.g., fossil marine beds). In this paper we develop a conceptual framework from which to derive expectations concerning the preservation of freshwater mussel remains focusing on two parameters, shell microstructure and shell shape. Shell size does not influence survivorship. Our model is validated through application to late Holocene zooarchaeological mussel assemblages from north Texas. Taphonomically robust species are important regarding zooarchaeological and biogeographic interpretations based on mussel paleofaunas, and fragile species are important indicators of whether or not an assemblage is well preserved.     

Riparian environment in shaping social and economic behavior during the first phase of the evolution of Late Neolithic tell complexes in SE Hungary (6th/5th millennia BC)

The period corresponding to the initial phase of cultural evolution in the Late Neolithic of SE Hungary (turn of the 6th and 5th millennia) is characterized by a major transformation recorded both in settlement structure and strategy, as well as material culture of the agrarian societies settled in the SE part of the Great Hungarian Plains. According to the available chronological data and archeology from the sites of multi-layered settlement complexes (tells) located on natural highs of the floodplain of the River Tisza, during the initial phase of its evolution representatives of the Tisza Culture were mainly confined to the SE part of the Great Hungarian Plains south of the Körös River. This period was followed by a relatively stable phase lasting about 150 years which hallmarked the greatest northward expansion of the culture. Some studies noticed strange features in connection with the first settlement complexes dated to the first period especially along the northern borderline of the culture’s distribution; i.e. a loose cluster of distinct settlement nuclei instead of concentration of settlements to a confined area characteristic of tells. Furthermore, by the end of the first phase, in the evolution of some settlements a northward shift of the houses away from the water was recorded. Most likely these reflect a socioeconomic response to some transformation in the local and/or regional riparian environment. As shown by our data gained from the paleoecological analysis of freshwater mollusks from a tell site, the referred pre-transitional period was characterized by pronounced floods causing major perturbations in the regional riparian environment. At the same time, the introduction of new subsistence strategies including shellfishing and fishing and the reordering of settlement structure was also recorded at several sites implying a successful adaptation to such most likely climate-induced perturbation, which is contemporary with the 5.1 ky event known in the literature.     

Stable isotope data from the early Christian catacombs of ancient Rome: new insights into the dietary habits of Rome's early Christians

This study reports on the first attempt that determines the diet of a small but conceivably representative section of Rome's early Christian community by means of δ¹³C and δ¹⁵N measurements on collagen extracted from twenty-two samples of human bone. Samples derive from the Liberian Region in the catacombs of St. Callixtus on the Appian Way—an area that has been radiocarbon dated to the period from the mid-3rd through early 5th century AD. Comparing our results to those produced for several other sites, we argue that this population's typical diet included freshwater fish. We also briefly discuss breastfeeding and the freshwater reservoir effect, to then explore the dietary, art historical, and possible sociological ramifications of our results.     

Modern and early-middle Holocene shells of the freshwater mollusc Unio, from Çatalhöyük in the Konya Basin, Turkey: preliminary palaeoclimatic implications from molluscan isotope data

Carbon and oxygen isotope ratios in the shells of the freshwater Unio mollusc yield information on the isotopic composition of the water in which the shell was formed, which in turn relates to climatic conditions prevailing during the bivalves’ life span. Here we analysed shells from one modern Unio, from a modern lake shore in Anatolia, and 4 subfossil Unio shells from Çatalhöyük (dated between 7200 BC and 5000 BC, Neolithic and Chalcolithic periods). Sequential carbon and oxygen isotope analysis along the surface of the shells provides information on seasonal or shorter-term variability of lake waters during the lifetime of the organisms. δ¹⁸O values of the modern shell are consistent with it being collected from a dammed portion of the Seyhan River that does not undergo intensive summer evaporation. This is in contrast to many of the surface water bodies in Anatolia which suffer extensive evaporation in the arid summers. δ¹⁸O values of the subfossil shells from the Çatalhöyük middens indicate that the bivalves came from lakes which evaporated extensively during the summer months but were replenished by high winter rainfall, suggesting that the subfossil shells lived in relatively small lakes or ponds. Stable isotope analysis along the growth of freshwater bivalves is one of the few methods for investigating seasonal water fluctuations in the past. These results may alter current interpretations on the environment of Çatalhöyük during the Neolithic, although more work is needed to confirm these initial findings.