Static penetration assessment of stone weapon tip geometry metrics and comparison of static and dynamic penetration depths

Many factors governed the penetration efficacy of prehistoric projectile weaponry. Archaeologists broadly focus their efforts on understanding the effect of stone weapon tips because these specimens are often the only part of the weapon system that survives in the archaeological record. The tip cross-sectional area (TCSA) and perimeter (TCSP) of stone weapon tips have been shown to correlate with target penetration depth. Here, using results from both static and dynamic penetration testing, we compare TCSA and TCSP against other tip geometry metrics: lateral surface area (LSA) and volume (V). Our analyses broadly show that using a single-point geometry metric evaluated at multiple locations along the length of the point, or using multiple geometry metrics evaluated at a single location, better predicts required energy than using a single-point geometry metric evaluated at a single location. Our results also show that in the case where a single geometry metric evaluated at multiple locations is used LSA provided the most robust prediction models. Finally, our results show that for the case where all geometry metrics evaluated at a single location are used the location that provides the most robust prediction model is dependent on how far the point penetrated the target.     

Remodeled human skulls in Köşk Höyük (Neolithic age,Anatolia): a new appraisal in view of recent discoveries

Between 1985 and 2007 overall nineteen human skulls dating to the Late Neolithic period were recovered at Kö?k Höyük, which lies within the borders of Bor, a district of the Ni?de Province in Central Anatolia. One of these skulls belongs to a child and the remainder to adult males and females. The plastered skulls may have been laid on or wrapped in mats and exposed either singly or in groups on a plaster surface inside the house. Among thirteen of these skulls the mouths, noses, eyes and ears were depicted with clay and painted with red ochre, while the remaining six were untreated. Two headless skeletons were also found in situ underneath the floor inside the house. One of these skeletons belongs to a child aged approximately 15–16 years old and the other belongs to an adult female. The modeled human skulls were encountered in the second and third cultural levels of the Late Neolithic period indicating that this characteristic mortuary practice lasted for quite a long time and likely disappeared by the Chalcolithic at Kö?k Höyük.     

Kuhn's Geometric Index of Unifacial Stone Tool Reduction (GIUR): does it measure missing flake mass?

Kuhn's GIUR is a set of measurements taken on a resharpened stone flake's edge. Its purpose is to estimate the amount of stone removed before the exhausted tool was abandoned. An experimental test of Kuhn's Index led Hiscock and Clarkson to suggest that it is an excellent estimator of flake mass loss. Our own tests, using different experimental procedures, reached much less optimistic conclusions. Here, we apply their own measurement procedures, and successfully duplicate their results. It does not follow, however, that our now-consistently high correlations have a causal connection. As GIUR values increase, they are less able to estimate the actual loss of flake mass. It appears, therefore, that incremental loss of flake mass need not be the sole driver of the GIUR value. If the correlation is an inevitable byproduct of the experiment's design, as it now appears, then analyses based on this high correlation will be misleading. The GIUR remains, however, and excellent gauge of flake edge exhaustion.     

An empirical test of the relative frequency of bipolar reduction in Beds VI,V, and III at Mumba Rockshelter,Tanzania: implications for the East African Middle to Late Stone Age transition

Mumba Rockshelter, Tanzania, is the only East African site spanning a continuous record of more than 100,000 years, including the Middle Stone Age (MSA) to Late Stone Age (LSA) Transition. Rather than examine the presence or absence of traditional markers of “behavioral modernity”, we have endeavored here to respond to the calls of Shea (2011) and Basell (2008) by examining the proportional similarity of a trait present throughout the MSA–LSA sequence at Mumba Rockshelter: the bipolar technique of lithic reduction. We use a quantified, experimentally derived proxy to track the relative amount of bipolar percussion among Mumba's Beds VI, V, and III, namely, waste shatter. Our examination of Mehlman's previously unanalyzed collections from Mumba demonstrates that in terms of bipolar production Bed V is statistically indistinguishable from the Late Stone Age (LSA) Bed III, but significantly different from the Middle Stone Age (MSA) Bed VI. Given that Bed V dates to 56.9 ± 4.8 − 49.1 ± 4.3 ka cal BP, this result is consistent with other evidence that the origins of the LSA in East Africa began well before 40 kya, and that Mumba Bed V represents one of the earliest manifestations of the LSA in East Africa. We conclude with a discussion of factors that may have influenced the increased dependence of bipolar production at the site.     

Comparison of four ballistic and thrusting target materials: An experimental and Bayesian approach using static testing of stone and steel arrow tips

Researchers use a variety of target materials, and sometimes combinations of materials, in their archaeological experiments to examine thrust-spear or projectile penetration, impact angle, durability, and other issues involving prehistoric hunting weaponry. This variety of target materials is beneficial to archaeological science in several ways, but it may also hinder the comparison of results because many of these target materials do not necessarily share similar physical properties. Here, we assess the penetration properties of four different target materials—store-bought meat, clay, and two types of gelatin—via static penetration tests of a modern broadhead-tipped arrow and a stone-tipped projectile attached to an Instron Universal Materials Tester. Our analyses of load-deflection curves, peak load, and work energy demonstrate how the four target materials are similar in some ways but different in others, which suggests that researchers may strategically employ one or several depending on the question asked or hypothesis tested.     

Toolstone constraints on knapping skill: Levallois reduction with two different raw materials

Lithic raw material constraints are widely assumed to be a determining factor of flaked stone tool morphology, but this assumption remains largely untested. We conducted a controlled experiment to determine whether a knapper’s growing replication skills would be hindered if the toolstone used was switched from large flakes of an easily worked chert to nodules of less tractable one. Two batches of Preferential Levallois cores were knapped, an earlier series made from standardised large flakes of sediments dominated by chalcedonic quartz followed by a more challenging one using variably-shaped, cortical nodules of microcrystaline quartz that varies in the completeness of quartz replacement of calcite and dolomite. Skill level markers were designed to measure the knapper’s ability to achieve a series of set goals. These were quantified and subjected to statistical testing. In all but one test, significant increases in skill could be detected from the earlier to the later batch of reductions, despite the drop in toolstone quality. Significant improvements in the consistency of the knapper’s output could also be detected. However, the switch to a more challenging, nodular chert did require extra shaping, which resulted in more waste. This masked visible progress towards producing a less costly core. Overall, our results do not support the assumed primacy of toolstone constraints over other factors in influencing the morphology of flaked stone tools.     

Design Space and Cultural Transmission: Case Studies from Paleoindian Eastern North America

Tool design is a cultural trait—a term long used in anthropology as a unit of transmittable information that encodes particular behavioral characteristics of individuals or groups. After they are transmitted, cultural traits serve as units of replication in that they can be modified as part of a cultural repertoire through processes such as recombination, loss, or partial alteration. Artifacts and other components of the archaeological record serve as proxies for studying the transmission (and modification) of cultural traits, provided there is analytical clarity in defining and measuring whatever it is that is being transmitted. Our interest here is in tool design, and we illustrate how to create analytical units that allow us to map tool-design space and to begin to understand how that space was used at different points in time. We first introduce the concept of fitness landscape and impose a model of cultural learning over it, then turn to four methods that are useful for the analysis of design space: paradigmatic classification, phylogenetic analysis, distance graphs, and geometric morphometrics. Each method builds on the others in logical fashion, which allows creation of testable hypotheses concerning cultural transmission and the evolutionary processes that shape it, including invention (mutation), selection, and drift. For examples, we turn to several case studies that focus on Early Paleoindian–period projectile points from eastern North America, the earliest widespread and currently recognizable remains of hunter–gatherers in late Pleistocene North America.     

Food and social complexity at Çayönü Tepesi,southeastern Anatolia: Stable isotope evidence of differentiation in diet according to burial practice and sex in the early Neolithic

The identification of early social complexity and differentiation in early village societies has been approached in the past most notably through the evaluation of rituals and architectural layouts. Such studies could be complemented by an approach that provides data about everyday behaviours of individuals. We took 540 human and animal bone samples for stable carbon and nitrogen isotope analysis from the Neolithic site of Çayönü Tepesi in southeastern Anatolia. The inhabitants at this site chose to bury their dead in two different ways at different times during its occupation: beneath the floors of their houses, but also inside a public mortuary building known as the Skull Building. This variation provides an opportunity using isotope methods to test whether there was evidence for structuring of daily activities (diet in this case) that might serve to reinforce this change in burial practice. We show that when the inhabitants of Çayönü Tepesi changed their architecture and operated different burial practices in conjunction, this coincided with other aspects of behaviour including socially-constituted food consumption practices, which served to reinforce social identities.     

Networks and Neolithisation: sourcing obsidian from Körtik Tepe (SE Anatolia)

This paper details the use of obsidian sourcing to reconstruct networks of interaction (or ‘communities of practice’) amongst populations of south-eastern Anatolia and the Near East in the context of ‘Neolithisation’ during the late 11th–early 10th millennia BC. EDXRF was used to elementally characterise 120 artefacts of Epi-Palaeolithic – Pre-Pottery Neolithic A date from Körtik Tepe in south-eastern Anatolia. Four eastern Anatolian sources are represented, mainly Bingöl A/B and Nemrut Da?, plus the first evidence for the use of Mu? obsidian. When the source data is integrated with the artefacts' techno-typological attributes it is possible to locate the assemblage within an Upper Tigris tradition (with some interesting local differences), which stands in stark contrast to contemporary practices in northern Mesopotamia and the Levant. These local and regional distinctions support recent views of the Neolithic being much more heterogeneous, with a ‘mosaic’ of community-specific/local traditions of subsistence practices, raw material choices and lithic technologies during the Younger Dryas–Early Holocene.     

Refuting the technological cornerstone of the Ice-Age Atlantic crossing hypothesis

The “North Atlantic Ice-Edge Corridor” hypothesis proposes that sometime during the Last Glacial Maximum, roughly 26,500–19,000 years ago, human populations from southern France and the Iberian Peninsula made their way across the North Atlantic and colonized North America. A key element of that hypothesis is the apparent similarity between stone-tool-production techniques of Solutrean peoples of Western Europe and Clovis and purportedly pre-Clovis peoples of eastern North America, most especially the supposed intentional use of “controlled overshot flaking,” a technique for thinning a bifacial stone tool during manufacture. Overshot flakes, struck from prepared edges of the tool, travel across the face and remove part of the opposite margin. Experimental and archaeological data demonstrate, however, that the most parsimonious explanation for the production of overshot flakes is that they are accidental products created incidentally and inconsistently as knappers attempt to thin bifaces. Thus, instead of representing historical divergence, overshot flakes in Clovis and Solutrean assemblages mark convergence in the use of the same simple solution for thinning bifaces that produced analogous detritus.