Analysis of 13C and 15N isotopes from Eurasian Quaternary fossils: Insights in diet, climate and ecology

Woolly mammoth fossils on an island where the species eventually dies out, human and animal fossils on the bottom of the North Sea, remains of Siberian unicorns and exceptionally well-preserved bones from 300,000 years ago from the famous Schöningen archaeological site in Germany: these are the main topics discussed in this thesis.In this dissertation, a vast amount of isotope (d13C and d15N) data from bulk collagen of Quaternary mammalian fossils are presented and discussed. Most of these data are measured at the Centre for Isotope Research (CIO), Groningen (n > 400). The dataset consists of samples from various localities within Eurasia and are taken from human fossils, but mainly from fossils of various animal taxa including extinct species. Many of these faunal species belong to the typical ‘Mammoth steppe fauna’.The results shed light on dietary and habitat characteristics of these animals and hominins through time and space, often during episodes of dramatic climate change. Overall, this thesis, a study of stable isotope data from mammalian fossils, contributes to our understanding of ecological conditions during the Pleistocene / Early Holocene in Eurasia.Parts of his work was financially supported by the Netherlands Organisation for Scientific Research (NWO) in the frame of the Russian-Dutch scientific cooperation COMSEC (i.e. The collapse of the mammoth steppe ecosystem, № 047.017.041) and by the Leiden University Fund (LUF), Van Trigt (№10602).Bioarchaeolog

Radiocarbon-based investigations into the authenticity of Mesoamerican artefacts in museum contexts

In this article, radiocarbon dating has been used as a tool for investigating the authenticity of two Mesoamerican artefacts from the collection of the National Museum of World Cultures (Museum Volkenkunde), Leiden, the Netherlands. The first artefact is a ceremonial Aztec, possibly a tecpatl, knife, and it is presumed to date to 1300–1500 CE. The second object is a decorated Mixtec skull, presumed to date to 1400–1520 CE. The efficacy of radiocarbon dating was thoroughly tested in this study, especially in regard to the tiny quantities that could be sampled from the skull. However, with the newly revamped radiocarbon facility at the University of Groningen, this was an opportune moment to attempt such research. Ultimately, a credible result could not be obtained on the skull; however, the ceremonial knife was dated reliably to the Aztec period. The article also discusses the broader issue of whether radio­carbon results can be used as a definitive proof of authenticity and examines the risk­reward nature of radiocarbon testing.Archaeological sciencesMuseum StudiesArchaeology of indigenous Americ

Geoarchaeological and palaeontological research in the Maasvlakte 2 sand extraction zone and on the artificially created Maasvlakte 2 beach: a synthesis

Zooarchaeolog

Evidence for European presence in the Americas in ad 1021

Transatlantic exploration took place centuries before the crossing of Columbus. Physical evidence for early European presence in the Americas can be found in Newfoundland, Canada(1,2). However, it has thus far not been possible to determine when this activity took place(3–5). Here we provide evidence that the Vikings were present in Newfoundland in ad 1021. We overcome the imprecision of previous age estimates by making use of the cosmic-ray-induced upsurge in atmospheric radiocarbon concentrations in ad 993 (ref. (6)). Our new date lays down a marker for European cognisance of the Americas, and represents the first known point at which humans encircled the globe. It also provides a definitive tie point for future research into the initial consequences of transatlantic activity, such as the transference of knowledge, and the potential exchange of genetic information, biota and pathologies(7,8)

Radiocarbon Production Events and their Potential Relationship with the Schwabe Cycle

Extreme cosmic radiation events occurred in the years 774/5 and 993/4 CE, as revealed by anomalies in the concentration of radiocarbon in known-age tree-rings. Most hypotheses point towards intense solar storms as the cause for these events, although little direct experimental support for this claim has thus far come to light. In this study, we perform very high-precision accelerator mass spectrometry (AMS) measurements on dendrochronological tree-rings spanning the years of the events of interest, as well as the Carrington Event of 1859 CE, which is recognized as an extreme solar storm even though it did not generate an anomalous radiocarbon signature. Our data, comprising 169 new and previously published measurements, appear to delineate the modulation of radiocarbon production due to the Schwabe (11-year) solar cycle. Moreover, they suggest that all three events occurred around the maximum of the solar cycle, adding experimental support for a common solar origin

Heavy reliance on plants for Romanian cave bears evidenced by amino acid nitrogen isotope analysis

Heavy reliance on plants is rare in Carnivora and mostly limited to relatively small species in subtropical settings. The feeding behaviors of extinct cave bears living during Pleistocene cold periods at middle latitudes have been intensely studied using various approaches including isotopic analyses of fossil collagen. In contrast to cave bears from all other regions in Europe, some individuals from Romania show exceptionally high δ15N values that might be indicative of meat consumption. Herbivory on plants with high δ15N values cannot be ruled out based on this method, however. Here we apply an approach using the δ15N values of individual amino acids from collagen that offsets the baseline δ15N variation among environments. The analysis yielded strong signals of reliance on plants for Romanian cave bears based on the δ15N values of glutamate and phenylalanine. These results could suggest that the high variability in bulk collagen δ15N values observed among cave bears in Romania reflects niche partitioning but in a general trophic context of herbivory

Findings from an in-depth annual tree-ring radiocarbon intercomparison

The radiocarbon (¹⁴C) calibration curve so far contains annually resolved data only for a short period of time. With accelerator mass spectrometry (AMS) matching the precision of decay counting, it is now possible to efficiently produce large datasets of annual resolution for calibration purposes using small amounts of wood. The radiocarbon intercomparison on single-year tree-ring samples presented here is the first to investigate specifically possible offsets between AMS laboratories at high precision. The results show that AMS laboratories are capable of measuring samples of Holocene age with an accuracy and precision that is comparable or even goes beyond what is possible with decay counting, even though they require a thousand times less wood. It also shows that not all AMS laboratories always produce results that are consistent with their stated uncertainties. The long-term benefits of studies of this kind are more accurate radiocarbon measurements with, in the future, better quantified uncertainties

FOSSIL BONES FROM THE NORTH SEA: RADIOCARBON AND STABLE ISOTOPE (13C/15N) DATA

The North Sea is considered a unique heritage site that yielded a huge amount of zoological and archaeological data. More than 200 palaeozoological and archaeological fossil bone samples from the North Sea bed are dated by 14C. About 2/3 of these dated bones are Pleistocene in age; the majority of the bones are from extinct species (in particular woolly mammoth); about 1/3 of the sample date to the Holocene. The presented dataset is important in its kind, but interpretation is limited because of a lack of context of the finds. The stable isotopes (13C, 15N) of the dated samples provide additional information on palaeoenvironmental conditions and dietary habits in the past. We present primarily a Groningen list of data; a few fossils dated in other laboratories are included for completeness

Synthese van het geo-archeologisch en paleontologisch onderzoek zandwingebied en buitencontour Maasvlakte 2

Zooarchaeolog