Preparation of bone powder for FTIR-ATR analysis: the particle size effect : The particle size effect

Fourier transform infrared (FTIR) spectroscopy using attenuated total reflection (ATR) is commonly used for the examination of bone. During sample preparation bone is commonly ground, changing the particle size distribution. Although previous studies have examined changes in crystallinity caused by the intensity of grinding using FTIR, the effect of sample preparation (i.e. particle size and bone tissue type) on the FTIR data is still unknown. This study reports on the bone powder particle size effects on mid-IR spectra and within sample variation (i.e. periosteal, mesosteal, trabecular) using FTIR-ATR. Twenty-four archaeological human and faunal bone samples (5 heated and 19 unheated) of different chronological age (Neolithic to post-Medieval) and origin (Belgium, Britain, Denmark, Greece) were ground using either (1) a ball-mill grinder, or (2) an agate pestle and mortar, and split into grain fractions (>500 μm, 250–500 μm, 125–250 μm, 63–125 μm, and 20–63 μm). Bone powder particle size has a strong but predictable effect on the infrared splitting factor (IRSF), carbonate/phosphate (C/P) ratio, and amide/phosphate (Am/P) values. The absorbance and positions of the main peaks, the 2nd derivative components of the phosphate and carbonate bands, as well as the full width at half maximum (FWHM) of the 1010 cm−1 phosphate peak are particle size dependent. This is likely to be because of the impact of the particle size on the short- and long-range crystal order, as well as the contact between the sample and the prism, and hence the penetration depth of the IR light. Variations can be also observed between periosteal, cortical and trabecular areas of bone. We therefore propose a standard preparation method for bone powder for FTIR-ATR analysis that significantly improves accuracy, consistency, reliability, replicability and comparability of the data, enabling systematic evaluation of bone in archaeological, anthropological, paleontological, forensic and biomedical studies

The role of birds at Çatalhöyük revealed by the analysis of eggshell

The exceptional eggshell assemblage from Çatalhöyük was studied using an integrated approach combining morphology (by optical and scanning electron microscopy) and palaeoproteomics (by mass spectrometry). We provide taxonomic classification for 90 fragments, of which only 11 remain undetermined. The striking predominance of Anseriformes (probably including greylag geese, as well as ducks and swans) in all types of deposits examined, including middens and burial fills, suggests that these eggs were exploited as food and, at the same time, had a special significance for the inhabitants of the site. We detected the presence of crane eggshell in contexts associated with both the world of the living and the world of the dead (consistent with the well-known importance of this bird at Çatalhöyük), as well as the possible but infrequent occurrence of bustards and herons. Overall, we suggest that eggshell analysis, together with osteological data and the archaeological context, can provide the basis for a nuanced understanding of the relationship between humans and birds in the past

Multi-analytical characterisation of red colouration on decorated ostrich eggshells from the Middle Bronze Age in Bahrain

In the early 1960s, a Danish archaeological team excavated a group of mounds in Bahrain dating back to 2000 BC. Among their finds were fragments of decorated ostrich eggshells that displayed rectangular engravings as well as red colouring on the outer surface and a uniform red tint on the inner surface. The unpigmented natural coloration of ostrich eggs is the result of adaptations to prevent overheating in the arid habitat, and therefore, the red hue was artificial. The aim of this research was to characterise this coloration. Elemental analysis revealed low iron content, ruling out the use of iron-rich pigments such as ochre, while analysis by molecular spectroscopy could not detect any compounds besides the characteristic constituents of the calcareous eggshell. Thermal experiments on modern eggshells, combined with chiral amino acid analysis, indicated that the red colour on the archaeological samples could have been due to exposure to moderate temperatures. This investigation provides valuable insights into the art and cultural practices of ancient Middle Eastern societies during the Middle Bronze Age, contributing to our knowledge of prehistoric archaeology

Stone Age imitation of a slotted bone point from Pärnu River (south-western Estonia)

This is an in-depth study of a mimicked slotted point, carved from a cervid longbone, found in the lower reaches of the Pärnu River. The 3D digital model, created during this study, provides an interactive and innovative tool for studying the object in detail. The AMS dating places the artefact at the very beginning of human habitation in the present-day territory of Estonia. SEM-EDS, ATR-FT-IR and GC-FID/MS analyses demonstrate that this unique object was probably originally partially covered with a mixture of red ochre and some coniferous resin, possibly as hafting adhesive. As this is a detailed replica of a slotted point, it also demonstrates how people themselves saw slotted points in the Early Mesolithic, also raising the question of the purpose of this replica â was it an ordinary arrowhead or rather a ritual object

Late Iron Age Whaling in Scandinavia

The use of bone from marine mammals as raw material in the manufacturing of gaming pieces in the Scandinavian late Iron Age have been observed and discussed during the last few years. New empirical studies have created a chronology as well as a typology showing how the design of the gaming pieces is tightly connected to different choices of raw material from antler in the roman and migration period, to whalebone in the 6 th century and walrus in the 10th century. The ocular examination of the whalebone can, however, rarely go beyond a determination of bone from cetaceans. The following article presents the results from 68 samples of whalebone gaming pieces that have been species determined using ZooMSms. The results show a consistent use of bones from North Atlantic right whale (Eubalaena glacialis) and is thus a strong argument for there being an active and largescale hunt for this type of whale starting inthe 6 h century. However, the manufacturing of gaming pieces was most likely not the reason for hunting whales, but merely a by-product that has survived in the archaeological record. Of greater importance was probably baleen, meat and the blubber that could be rendered into oil. The oil might have been an additional trading product on the far-reaching trade networks developing during the period

Ancient amino acids from fossil feathers in amber

Ancient protein analysis is a rapidly developing field of research. Proteins ranging in age from the Quaternary to Jurassic are being used to answer questions about phylogeny, evolution, and extinction. However, these analyses are sometimes contentious, and focus primarily on large vertebrates in sedimentary fossilisation environments; there are few studies of protein preservation in fossils in amber. Here we show exceptionally slow racemisation rates during thermal degradation experiments of resin enclosed feathers, relative to previous thermal degradation experiments of ostrich eggshell, coral skeleton, and limpet shell. We also recover amino acids from two specimens of fossil feathers in amber. The amino acid compositions are broadly similar to those of degraded feathers, but concentrations are very low, suggesting that much of the original protein has been degraded and lost. High levels of racemisation in more apolar, slowly racemising amino acids suggest that some of the amino acids were ancient and therefore original. Our findings indicate that the unique fossilisation environment inside amber shows potential for the recovery of ancient amino acids and proteins

Neolithic farmers or Neolithic foragers? Organic residue analysis of early pottery from Rakushechny Yar on the Lower Don (Russia)

The emergence of pottery in Europe is associated with two distinct traditions: hunter-gatherers in the east of the continent during the early 6th millennium BC and early agricultural communities in the south-west in the late 7th millennium BC. Here we investigate the function of pottery from the site of Rakushechny Yar, located at the Southern fringe of Eastern Europe, in this putative contact zone between these two economic ‘worlds’. To investigate, organic residue analysis was conducted on 120 samples from the Early Neolithic phase (ca. mid-6th millennium BC) along with microscopic and SEM analysis of associated foodcrusts. The results showed that the earliest phase of pottery use was predominantly used to process riverine resources. Many of the vessels have molecular and isotopic characteristics consistent with migratory fsh, such as sturgeon, confrmed by the identifcation of sturgeon bony structures embedded in the charred surface deposits. There was no evidence of dairy products in any of the vessels, despite the fact these have been routinely identifed in coeval sites to the south. Further analysis of some of the mammalian bones using ZooMS failed to demonstrate that domesticated animals were present in the Early Neolithic. Nevertheless, we argue that intensive exploitation of seasonally migratory fsh, accompanied by large-scale pottery production, created storable surpluses that led to similar socio-economic outcomes as documented in early agricultural societies

Multi-method Analysis of Avian Eggs as Grave Goods: Revealing Symbolism in Conversion Period Burials at Kukruse, NE Estonia

Eggshells are unusual finds in the Iron Age of eastern Europe (500 BC–1200 AD) deserving extra attention in terms of analysis as well as interpretation. This paper discusses two rare eggshell finds, discovered in female burials at the conversion period (12th–13th century AD) cemetery at Kukruse, NE Estonia. Our multianalytical study combining FT-IR, SEM(-EDS), microscopy and ZooMS provides an overview of methods applicable for identifying egg species, their predepositional history and curation. Based on the analytical results and the comparative analysis of the content and context of these two burials, we argue that different aims and connotations lay behind depositing eggs as burial goods, allowing well-supported interpretations of both pagan and Christian religious worldviews simultaneously