Birch bark tar was used extensively throughout human history. While later ceramic-based production technologies are known, prehistoric aceramic techniques leave little to no archaeological evidence. Experimental tar production attempts to fill this gap and suggest potential techniques. However, their archaeological relevance is unclear. Through an in-depth biomolecular analysis using Gas Chromatography-Mass Spectrometry, this study attempts to differentiate tars produced using four experimental aceramic techniques: condensation, ash mound, pit roll, and raised structure. In doing so we publish the largest collection of GC-MS results of aceramic birch tars. The results show that pentacyclic triterpenoids, characteristic of birch bark, vary between the production techniques in relation to heating exposure and perhaps the tar collection method. This allows for a tentative identification of tars produced through the condensation and ash mound techniques, which were formed consistently using short periods of heating and collected systematically by scraping. In contrast, tars produced using the pit roll and raised structure techniques do not have consistent molecular signatures. Despite the partial success of Gas Chromatography-Mass Spectrometry, the archaeological relevance is questioned because this technique is only applicable to samples from optimum lipid preservation conditions when a high number of pentacyclic triterpenoids are preserved. Therefore, using Gas Chromatography-Mass Spectrometry to determine the transformation methods of organics, like birch bark, may not be an appropriate standalone technique to fairly discuss the technological capabilities of past populations.@en

In this paper I present the results of a micro-residue study conducted on ten pièces esquillées (scaled pieces) from Sibudu Cave, South Africa. These artefacts are associated with the Howiesons Poort Industry (∼61.7 and ∼64.7 ka years ago at Sibudu), representing part of the later phase of the Middle Stone Age. Until now, it was unclear on what these pieces were used, and whether they were functional. Previous experimental use-wear work tentatively pointed towards bone processing. However, replication work on stone tool production technology suggests that pièces esquillées are merely the by/end-product of bipolar knapping. I used residue analysis on the Sibudu artefacts because this alternative method has the potential to identify if they were used, and if so, illuminate the specific materials the pieces were used on. Although the sample is small, all the pièces esquillées reveal a clear animal processing signal. There are some bone deposits on the utilised edges that may substantiate bone processing, or perhaps a bone hammer was used with them, but additional study, including Later Stone Age artefacts, is needed to assess the feasibility of these observations. It remains possible that the artefacts are core reduced pieces that were subsequently used as tools or simply knapped with a bone hammer.@en

I report here on a micro-residue study of Early Stone Age artefacts from Sterkfontein, South Africa. A total of 33 artefacts was analysed. One part of the sample is attributed to the Oldowan and dates to around two million years ago; another part is attributed to the Acheu-lean industry, dating to around 1.5 million years ago. Previously, the pieces have been shown to hold micro-residues and ancient DNA. However, due to the great age of the samples, it has been questioned whether the micro-residues were use-related. To investigate this, I conducted a micro-residue study on part of the originally analysed sample and on other artefacts with the same provenance; the tools were analysed with a light microscope. Here, I first review the taphonomic history of the samples and second, report on the results of the microresidue analysis. The taphonomic history of the artefacts is complex: biological, mechanical and chemical decay of the organic microresidues would have prevailed in the Sterkfontein setting and it is highly unlikely that micro-residues are preserved. In addition, the recorded micro-residue distributions fail to satisfy a number of basic criteria designed to distinguish use-related residues from microcontaminants. There is also an obvious contaminant signal in the form of brightly coloured remains, pollen and ink. Based on these multiple lines of evidence, it is concluded that the recorded remains are not use-related and the contaminant micro-residues probably originate from post-excavation handling and curation. The previous study focused on single remains, whereas this analysis includes the fidl context of the micro-residues. As a result of the different approach used here, the interpretation of the micro-residues differs.@en

The influence of transport and processing behaviour on the composition of archaeological assemblages is often poorly understood. We study the influence of changing transport distances, due to Late Pleistocene sea-level fluctuations, on the representation of marine resources at Middle Stone Age sites in South Africa. We show that the representation of some marine resources does not decrease proportionally with increased transport distance. This suggests that the organisation of foraging behaviour changed as sea levels fluctuated. We develop a model of the organisation of Middle Stone Age coastal foraging strategies, explaining the exploitation of marine resources as a function of fluctuations in the productivity of terrestrial relative to marine resources.@en

In this paper I explore how post-depositional contaminants and non-use related ancient residues may be distinguished from use-related residues directly associated with the application of ancient artefacts. It is assumed that contaminant and unintentional remains have a random distribution over a tool's surface. Preserved use-related residues, however, are expected to have a consistent spatial distribution around a working edge. To test this, residues on used and unused experimental flakes were recorded after they underwent weathering. The surfaces of the experimental flakes were divided in four quadrants, of roughly equal size. The surface coverage of the residue types per quadrant was then recorded. On used flakes with well preserved residues, the use-related residues are more abundant on portions associated with the sharp edge than on portions associated with blunt sides. On the samples without identified use-related remains and on the unused sample, the distribution of micro-remains is more uniform. This study confirms that by using a contextual approach it is possible to distinguish use-related remains from non-use-related and co-incidental remains.@en

Osseous barbed and unbarbed points are commonly recovered from the Dutch North Sea and other Mesolithic sites of northern Europe. Interpreted as elements of projectile weaponry, barbed points are considered by archaeologists to be a technological innovation in the hunting equipment of hunter-gatherers. However, debate about their exact use and identification of the targeted prey species is still ongoing. To shed light on the function of these tools, we analysed a sample of 17 artefacts from the Netherlands with a multi-disciplinary approach encompassing morphometric, functional, and chemical analysis. 14C-AMS dating yielded the oldest date for a barbed point from the Dutch coast (⁓13000 cal. BP). The observation of microwear traces preserved on the tools provides solid evidence to interpret the function of barbed and unbarbed points. We show that there were two distinct tool categories. 1) Barbed points hafted with birch tar and animal or vegetal binding were likely projectile tips for terrestrial and aquatic hunting. We provide strong clues to support the link between small barbed points and fishing using wear traces. 2) Points without barbs served as perforators for animal hides. Our results highlight the importance of use-wear and residue analysis to reconstruct prehistoric hunting activities. The functional interpretation of projectile points must also rely on microwear traces and not merely on the association with faunal remains, historical sources, and ethnographic comparisons.@en

The intentional production of birch bark tar by European Neanderthals as early as 190,000 years ago plays an important role in discussions about the technological and behavioural complexity of Pleistocene hominins. However, research is hampered because it is currently unknown how Neanderthals were producing birch tar. There are several different techniques that could have been employed, but these differ in their apparent production complexity, time and resource efficiency. Identifying production processes in the archaeological record is therefore paramount for furthering research on the technical behavioural repertoire. Organic biomarkers, identified with Gas Chromatograph–Mass Spectrometry (GC–MS), have been used to identify possible production processes during the Neolithic. Here we test whether these biomarkers can also distinguish Palaeolithic (aceramic) tar production methods. We produced tar using five different methods and analysed their biomolecular composition with GC–MS. Our results show that the biomarkers used to distinguish Neolithic tar production strategies using ceramic technology cannot be reliably used to identify tar production processes using aceramic Palaeolithic techniques. More experimentation is required to produce a larger reference library of different tars for future comparisons. To achieve this, complete GC–MS datasets must also be made publicly available, as we have done with our data.@en

In 2016 raapte amateurarcheologe en -paleontologe Willy van Wingerden uit Honselersdijk op het strand bij Kijkduin een klein stukje vuursteen op met aan één kant een aangehechte zwarte materie. Ze liet de vondst enkele dagen later aan archeoloog Marcel Niekus zien. Die werd direct enthousiast, het zwarte goedje zou wel eens berkenpek kunnen zijn. Daarmee werden in de prehistorie werktuigen vastgezet aan een schacht. Het bleek een topvondst te zijn, vergeleken met de vele ‘gewone’ vuurstenen artefacten die op dit strand werden gevonden. Niemand kon toen nog vermoeden dat deze vondst drie jaar later wetenschappelijk wereldnieuws zou zijn en een nieuw licht zou werpen op het gedrag van de neanderthalers.@en

Middle Stone Age (MSA) shellfish remains were studied for indications of changes in subsistence adaptations. Optimal Foraging Theory was applied to the MSA shellfish species from Blombos Cave and Klasies River, South Africa, to model which shellfish would be most profitable to collect in terms of meat yield and handling costs. This ranking is compared to the composition of the archaeological shellfish assemblages. Several developments are considered to be the result of changes in prey choice. It appears that at Klasies River, MSA people mainly collected high ranked mid-intertidal shellfish, and that their foraging strategy was strongly influenced by changes in the coastal environment. At Blombos Cave, when the sea was further from the cave, a revaluation of the prey ranking caused an increase in . Perna perna densities in the M2 and M1 phases, compared to the older M3 phase. . P. perna was not only selected because, as a bivalve it preserves better during transport, but also because it can easily be mass collected. At Blombos Cave there are changes in species representation and a decrease in average . Turbo sarmaticus opercula weight. This tentatively suggests that shellfish collection may have intensified during later phases. In general, MSA collecting trips were optimized according to the available shellfish, taking into account the distance to the resource and their yield.@en

We report the discovery of a 50,000-y-old birch tar-hafted flint tool found off the present-day coastline of The Netherlands. The production of adhesives and multicomponent tools is considered complex technology and has a prominent place in discussions about the evolution of human behavior. This find provides evidence on the technological capabilities of Neandertals and illuminates the currently debated conditions under which these technologies could be maintained. 14C-accelerator mass spectrometry dating and the geological provenance of the artifact firmly associates it with a host of Middle Paleolithic stone tools and a Neandertal fossil. The find was analyzed using pyrolysis-gas chromatography-mass spectrometry, X-ray micro-computed tomography, and optical light microscopy. The object is a piece of birch tar, encompassing one-third of a flint flake. This find is from northwestern Europe and complements a small set of well-dated and chemically identified adhesives from Middle Paleolithic/Middle Stone Age contexts. Together with data from experiments and other Middle Paleolithic adhesives, it demonstrates that Neandertals mastered complex adhesive production strategies and composite tool use at the northern edge of their range. Thus, a large population size is not a necessary condition for complex behavior and technology. The mitigation of ecological risk, as demonstrated by the challenging conditions during Marine Isotope Stage 4 and 3, provides a better explanation for the transmission and maintenance of technological complexity.@en

This study explores traditional adhesives using an ethnobiological approach within a multisocioecological context in Zambia. Through semi-structured interviews, videotaped demonstrations, and herbarium collections, we investigated the traditional adhesives people know and use, the flexibility of production processes, resource usage, and knowledge transmission in adhesive production. Our findings reveal flexibility in adhesive production systems. People use a wide range of organic and inorganic materials in their adhesive recipes. Recipes are flexible, demonstrating the ability to adapt to changes and substitute materials as needed to achieve the desired end product. Additionally, our study reveals a variety of redundant pathways for knowledge transmission typically confined within individual population groups. These include same-sex vertical transmission and distinct learning spaces and processes. Also, we identified material procurement zones showing that people are prepared to travel 70 km for ingredients. We use our findings to review the archaeology and we discuss the identification of archaeological adhesives, the functional roles of adhesive materials, adhesive storage, and the sustained human interaction with species from families such as Euphorbiaceae and Apiade. Our findings underscore the diversity and adaptability of traditional adhesive production and suggest that further research on adhesives would reveal similar diversity within the archaeological record.@en

An adhesive is any substance that bonds different materials together. This broad definition includes materials used in everything from hafted stone tools to monumental architecture. In addition, the combination of bonding, plasticity, and insolubility meant that some adhesives were exploited for waterproofing and sealing of materials, as self-adhering inlays and putties, and as paints, varnishes, and inks. Adhesives have a history of at least 200,000 years. Throughout (pre)history and around the world, people used materials, including bitumen/ asphalt, carbohydrate polymers such as starches and gums, natural rubbers, mortars, proteins (from casein, soy, blood, and animal connective tissue), insect and plant resins, and tars made from various barks and woods. Adhesives thus are very diverse and have widely varying properties: they can be tacky, pliable, elastic, brittle, water-resistant, fluid, viscous, clear, dark, and much more. They are a plastic avant la lettre. These properties can and were tweaked by mixing ingredients or by further processing. In the study of archaeological adhesives, their characterization is essential and this is best done with chemical and spectroscopic methods. When larger coherent samples as opposed to single finds are analyzed, adhesive studies can provide data on past technologies, socioeconomic organizations, and environments and raw material availability. Through sourcing and mapping of ingredients and adhesive end products, travel and transfer of materials and knowledge can be illuminated. Additionally, experimental reproductions provide data on technological aspects that otherwise are lost in the archaeological record. An archaeology of adhesives can reveal the transport networks, subsistence, mobility strategies, division of labor, and technological know-how that held societies together.@en

Adhesives are an important yet often overlooked aspect of human tool use. Previous experiments have shown that compound resin/gum adhesive production by anatomically modern humans was a cognitively demanding task that required advanced use of fire, forward planning, and abstraction among other traits. Yet the oldest known adhesives were produced by Neandertals, not anatomically modern humans. These tar or pitch adhesives are an entirely different material, produced from a distinct, albeit similarly complex process. However, the material properties of these adhesives and the influence of the production process on performance is still unclear. To this end we conducted a series of laboratory based lap shear and impact tests following modern adhesive testing standards and at three different temperatures to measure the strength of pine and birch pitch adhesives. We tested eight different recipes that contain charcoal as an additive (mimicking contamination) or were reduced by boiling for different lengths of time. Lap shear tests were conducted on wood and flint adherends to determine shear strength on different materials, and we conducted high load-rate tests to understand how the same material behaves under impact forces. Our results indicate that both pine and birch pitch adhesives behave similarly at room temperature. Pine pitch is highly sensitive to the addition of charcoal and further heating. Up to a certain extent charcoal additives increases performance, as does extra seething. However, too much charcoal and seething will reduce performance. Similarly, pine pitch is sensitive to ambient temperature changes and it is strongest at 0°C and weakest at 38°C. Adhesive failures occur in a similar manner on flint and wood suggesting the weakest part of a flint-adhesive-wood composite tool may have been the cohesive strength of the adhesive. Finally, pine pitch adhesives may be better suited to resisting high-load rate impacts than shear forces. Our experiments show that pitch production and post-production manipulation are sensitive processes, and to obtain a workable and strong adhesive one requires a deep understanding of the material properties. Our results validate previous archaeological adhesive studies that suggest that the manufacture and use of adhesives was an advanced technological process. @en