Constraints on Levallois Core Technology: A Mathematical Model

Recent volumetric definitions of Levallois core technology are amenable to mathematical modelling. We present a simple geometric model that permits controlled manipulation of a few of the key parameters defining Levallois core morphology. The models indicate that Levallois cores are relatively efficient at minimizing raw material waste while at the same time maximizing productivity in terms of total number of tool blanks and amount of cutting edge produced. Deviations from an ideal Levallois geometry produce significant declines in both efficiency and productivity. These results implicate mechanical and economic constraints as factors underlying the broad geographic distribution and temporal persistence of Levallois core technologies during the Middle and Late Pleistocene.     

Levallois economics: an examination of ‘waste’ production in experimentally produced Levallois reduction sequences

Mathematical modelling has suggested that Levallois core morphology represents a reduction strategy driven by economic considerations; particularly the minimization of ‘waste’ while aiming to maximize cutting edge length of flakes obtained from cores of a given size. Such models are elegant in that they facilitate formal modelling of economic considerations that potentially motivate patterns seen in prehistoric data. However, the abstract nature of such models means that they do not take full account of all the practical difficulties and material challenges involved in reproducing Levallois-style reductions in stone. In particular, such models have only examined nodule morphology in two-dimensions, and did not take account of the fact that in the case of classic (lineal) Levallois reduction, core surfaces must be re-prepared between successive stages of flake removal. Hence, the potential economic implications of these factors are currently unknown, potentially undermining the significance of models that assume specific economic conditions. Here, we undertook to examine these factors using a series of experimentally produced Levallois reduction sequences. A total of 3957 flaking events were considered in our analyses, and we used six specific measures of economy to examine Levallois reduction across successive phases. Our analyses found that key assumptions of mathematical models suggesting that Levallois core morphology was driven by economic considerations (i.e. conservation of raw material when attempting to remove flakes with long cutting edges) can be upheld under the practical challenges of replicating Levallois-style reduction in stone. In supporting the notion that Levallois reduction has advantageous economic properties, our results emphasize the importance of considering why Levallois reduction did not emerge earlier in the archaeological record, and indeed, why even during the later Pleistocene the temporal and geographic distribution of Levallois technology varies. Our results also re-emphasize the value of formally modelling lithic reduction strategies in specific economic terms.     

Prepared core reduction at the site of Kudu Koppie in northern South Africa: temporal patterns across the Earlier and Middle Stone Age boundary

Kudu Koppie is a stratified late Earlier Stone Age and Middle Stone Age archaeological site located in the northern Limpopo Province of South Africa. The prepared core reduction strategies are described and temporal trends across the ESA–MSA boundary are presented. The prepared cores and endproducts of Kudu Koppie suggest that both the late ESA and MSA toolmakers employed the Levallois Volumetric Concept, but they often exploited a nodule's natural convexities and form. The MSA toolmakers used a greater variety of prepared core methods and more intensively exploited cryptocrystalline and microcrystalline nodules, the scarcity of which may have resulted in a more “formalized” application of the Levallois Volumetric Concept. These observations are considered within the context of human behavioural evolution.     

Measuring core reduction using 3D flake scar density: a test case of changing core reduction at Klasies River Mouth,South Africa

A new core reduction index is presented, calculated as the ratio of flake scar number to 3D surface area (SDI). The index is tested experimentally on five types of core (blade, discoid, Levallois, biface and multiplatform cores) and then applied to the core assemblages from five sub-stages of the Middle Stone Age at Klasies River Mouth, South Africa. Preliminary results indicate that the SDI possesses the desirable attributes of a successful reduction index and is a significant improvement on traditional proxy measures of core reduction. The results of the archaeological case study confirm previous untested observations that cores from the Howiesons Poort and MSAIII sub-stages are more heavily reduced than preceding and following stages, and that local and exotic raw materials as well as different types of cores are all more heavily reduced during these periods. The SDI fills a significant lacuna in available core reduction measures.     

Reconnaissance of Prehistoric Sites in the Red Sea Coastal Region of the Sudan,NE Africa

This paper reports results of a recent Stone Age-focused archaeological survey in the Red Sea coastal region of the Republic of Sudan, northeast Africa. Bifaces (handaxes) are the most conspicuous artifact class encountered during the survey and are characteristic of the Acheulean technocomplex. Other recorded artifact types include points, scrapers, and prepared core products referable to the Nubian and recurrent Levallois methods. Most of the artifact-bearing localities lie landward—outside of the coastal margin—thus, the evidence does not signify direct coastal adaptation per se. Our preliminary findings suggest that multiple Pleistocene-age hominin settlements tied to a terrestrial niche existed in the region. The western margin of the Red Sea occupies a pivotal location, linking the Horn of Africa and the Levant, two vital regions in human evolutionary research. Thus, the Stone Age data from the Sudan region has direct relevance for assessing hominin dispersal routes out of Africa.     

The relative effects of core surface morphology on flake shape and other attributes

It is long been thought that many flake attributes, including both size and shape, are largely due to the morphology of a core’s flaking surface, yet this has never been tested under strictly controlled conditions. Using molded glass cores with surface morphologies that highly resemble prehistoric ones, this experiment demonstrates that while core surface morphology does exhibit some influence on flake size and shape, a high degree of variation in flakes produced with the same core surface morphology shows that the effects of other independent variables, such as exterior platform angle and platform depth, have an even stronger effect. A major implication of these results is that current approaches to reconstruct prehistoric knapping strategies are overlooking significant sources of variation.     

Why is there a lack of Mode 3 Levallois technologies in East Asia? A phylogenetic test of the Movius–Schick hypothesis

The ‘Movius–Schick hypothesis’ claims that an absence of Levallois (Mode 3) technologies in East Asia is due to the lack of a strong ancestral Acheulean (Mode 2) tradition in that region. Hence, this hypothesis is based on the assumption that similarities between Acheulean handaxes and Levallois cores can be interpreted as being phylogenetically homologous (i.e. due to common technological ancestry) as opposed to being homoplasic (i.e. due to convergent technological evolution). Here, the phylogenetic basis of this hypothesis is tested using a formal cladistic procedure. Under the framework of an ‘iterative’ approach to phylogenetic analysis, a series of post-hoc tests and re-evaluations of results follow the initial cladistic analysis. Results of these combined analyses indicate that morphological similarities between Mode 2 Acheulean handaxes and Mode 3 Levallois cores can, most parsimoniously, be seen as phylogenetically homologous. Hence, these results support the tenets of the ‘Movius–Schick’ hypothesis in suggesting that a lack of Levallois industries in East Asia may be due to the paucity of an ancestral Acheulean tradition in that region. The implications of these phylogenetic analyses for the concept of Palaeolithic ‘Modes’ are discussed. It is further suggested that low demographic levels (i.e. small effective population sizes) in East Asia may have constrained the technological phylogenetic trajectory of East Asia compared with that seen in other regions of the Old World during the Lower Palaeolithic. In addition, it is hoped that several methodological issues discussed here will contribute to the growing field of cultural phylogenetic analysis.     

A Statistical Examination of Flake Edge Angles Produced During Experimental Lineal Levallois Reductions and Consideration of Their Functional Implications

Recent studies have indicated that Levallois-style core reduction offered potential practical benefits to hominin populations. However, none of these studies have yet considered one of the most important functional attributes of flake tools, which is edge angle. To address this shortcoming, we statistically examined flakes produced experimentally during “classic” or “lineal” Levallois core production and reduction. The primary aim of our analyses was to statistically test the null hypothesis of “no difference” between the edge angles of “Levallois” products and the flakes involved in their production. We employ existing edge angle analytical techniques and develop new comparative methodologies to assess flake blank standardization through the case of Levallois core reduction. Having determined the statistical properties of our experimental Levallois reductions, we thereafter evaluated to what extent edge angles produced may, or may not, have been useful to prehistoric hominins. Our analyses demonstrated that the experimentally produced Levallois edge angles were indeed statistically different from the flakes involved in their production. These differences were evident both in terms of relatively higher (i.e., more obtuse) edge angles than debitage flakes and in being significantly less variable around their higher mean edge angles compared to debitage flakes. However, based on current knowledge of how flake edge angle properties relate to issues of functionality, such differences would not have been detrimental to their functionality. Indeed, the edge angle properties they possess would have provided distinct benefits to hominins engaged in their manufacture. Most notably, Levallois-style core organization and reduction would have provided hominins with a reliable means of consistently producing flakes (i.e., “Levallois flakes”) possessing average flake angles that are beneficial in terms of providing a viable cutting edge yet not being so acute as to be friable upon application. Hence, edge angle properties join an array of other features that provide logical motive for why hominins may have organized core production and reduction around Levallois-style patterns at various times and places during the Mid-Late Pleistocene.     

Psychological components of middle paleolithic technology: The proceduralization of lithic core reduction

Exploring the evolution of human cognition has been as methodologically problematic as it has been a vital area of study over the last couple of decades. In particular, the integration of archaeology and psychology, while fundamental to many such studies, has suffered from a difficulty by many researchers to effectively link models from the cognitive sciences with the archaeological data ( [Wynn, 2009] and [Wynn and Coolidge, 2010] ). In the current study one psychological process, proceduralization is used to examine the technological strategies that underpin the sequential nature of lithic core reduction. This is done via the application of sequential lithic information analysis (SLIA), a method developed by the author for the concurrent study of qualitative and quantitative sequential information. In the present context SLIA helps elucidate both the micro- and macro-level dynamics that underlie the reduction of a sample of Middle Paleolithic refitted Levallois cores from the site of Taramsa-1, Upper Egypt. The results of this study provide an explanation for the variability recognised within the Levallois technology and also speak to the existence of certain aspects of modern cognition by ca. 70,000 years before present.     

Is the Soanian techno-complex a Mode 1 or Mode 3 phenomenon? A morphometric assessment

The Soanian is traditionally seen as one of the major (non-Acheulean) Palaeolithic techno-complexes of the Indian subcontinent. Over several decades comparisons of Soanian assemblages have been made with the non-bifacial industries of East Asia and north-west Europe. The chronological status and typo-technological relationship(s) of the Soanian to other Palaeolithic industries have been the subject of much debate. When first named and described the Soanian was considered to contain evidence of Mode 3 Levallois-style core reduction. However, in recent years, the potential Mode 3 component of the Soanian has largely been ignored, and the techno-complex is described under various guises as a core/flake or ‘Mode 1’ techno-complex. Here, a comparative morphometric assessment of selected Soanian cores and other Palaeolithic nuclei is undertaken, to test the hypothesis that this industry contains a definite Mode 3 Levallois element. Discriminant Function Analyses (DFA) of morphometric variables provide robust evidence that at least part of the Soanian techno-complex contains Mode 3 Levallois cores. The implications of these analyses for the relationship between the Soanian and the Acheulean, and the relevance of the Soanian in considerations of the Movius Line are also discussed.     

Comparison of 3D Landmark and 3D Dense Cloud Approaches to Hominin Mandible Morphometrics Using Structure‐From‐Motion

The objective of this study is to compare landmark‐based assessment of hominin mandible morphological variation with that from a high‐density point cloud, using 3D models constructed from structure‐from‐motion (SfM) surface capture techniques. Surface models of nine hominin mandible casts were created using SfM photogrammetry. The morphology of these models was described using traditional geometric morphometrics based on identification of landmarks. This was compared to the morphological variation described by the differences between high‐density point clouds, which do not rely on anatomical landmarks, using an iterative closest point algorithm. The landmark‐based approach grouped the anatomically modern human and Neanderthal mandibles with reasonable success. The high‐density point cloud approach also grouped these successfully, but was able to incorporate information from a specimen that was insufficiently preserved to be included in the landmark data set. This improved the accuracy of the grouping. The use of high‐density point clouds from surface capture to analyse hominin mandible morphology allows for greater amounts of information to be included and offers a potential method to identify shape affinity that is as successful as landmark‐based geometric morphometrics.     

Experimental Tests of Middle Palaeolithic Spear Points Using a Calibrated Crossbow

Controlled experiments using a calibrated crossbow to thrust stone-tipped spears into animal carcasses reveal a relationship between Levallois point morphology and their performance as spear points. A comparative study of morphometric variation of Levallois points from Levantine Mousterian contexts supports the hypothesis that the demand for stone spear points was an important factor in Levallois point production.     

Introducing a new experimental design for controlled studies of flake formation: results for exterior platform angle,platform depth,angle of blow,velocity, and force

Potential variables that underlie variation in flake size, and in some instances shape, are investigated in a newly designed experiment. This new design, which utilizes glass cores molded to a specific shape, results in flakes that are identical to archaeological ones. Variation in exterior platform angle, platform depth and angle of blow all directly affect flake size, and in the case of exterior platform angle, flake shape as well (in spite of constant core surface morphology). In treating velocity and force independently, neither is found to affect flake size or shape. These results have implications for understanding different strategies that flintknappers may employ to control the size of their flake products.     

Three Scenarios Of The Middle To Upper Paleolithic Transition The Middle to Upper Paleolithic Transition in Africa and the Early Peopling of Eurasia by Anatomically Modern Humans

Previous papers of this cycle describe the Middle to Upper Paleolithic transition in Eurasia and in the Sino-Malayan zone. Archaeological evidence from Africa however, suggests a completely different model of the transition. Despite the variability of Paleolithic industries in Africa, the maintenance of the Middle Paleolithic strategy of core reduction constitutes a common trend. The transitional industries in North and East Africa are characterized by Aterian points and backed geometric implements.     

Assessing Collector Bias: A Geometric Morphometric Analysis of a Collection of Isolated Clovis Points from the Midcontinent

Clovis points are found across the contiguous United States as isolated surface finds and as elements of assemblages in surface and subsurface deposits. Despite being scattered over the continent, Clovis points exhibit a remarkable degree of standardization, yet there is still a demonstrable level of variation in their shapes across regions. Including isolated points in regional comparative analyses would significantly increase sample sizes and spatial coverage of these analyses; however, the effects of collector bias—the tendency to collect the most typical and aesthetically pleasing points—are unknown. Here, we examine the shape of a sample of isolated Clovis points from the midcontinent using geometric morphometric techniques. We show that resharpening had little effect on the shape of points and that our sample of isolated points are similar in shape to points from assemblages in the midcontinent. Our findings suggest that isolated points have research potential when collector bias is limited.     

Core Use-Life Distributions in Lithic Assemblages as a Means for Reconstructing Behavioral Patterns

Artifacts with varying use-lives have different discard rates and hence are represented unequally among archaeological assemblages. As such, the ability to gauge the use-lives of artifacts is important for understanding the formation of archaeological assemblage variability. In lithic artifacts, use-life can be expressed as the extraction of utility, or work potential, from existing stone volume. Using experimental data and generalized linear modeling, this study develops models of artifact use-life on cores in the form of reduction intensity. We then apply these models to two archaeological case studies to (a) reconstruct the reduction intensities of archaeological cores and (b) investigate the survivorship curves of these archaeological cores across the reduction continuum using the Weibull function. Results indicate variation in core reduction and maintenance with respect to raw material properties and place use history and implicate evolutionary differences between Early Stone Age hominins and Holocene modern humans.     

Morphometric Variability of Roman Dogs in Hispania Tarraconensis: The Case Study of the Vila de Madrid Necropolis

The size, body conformation and skull shape of Roman dogs from the ‘Vila de Madrid necropolis’ site, where 1480 dog remains were recovered, are described in this paper to provide evidence of the morphometric variability of Roman dogs in Hispania Tarraconensis. The individualized and detailed morphometric analysis of 10 individuals shows that the proliferation and explosion of the morphological variability already documented in different regions of the Roman Empire (Italia, Gallia, Britannia, Pannonia) are also noted here. The presence of very different individuals in terms of their shape and size, similar to the differences that can at present be noted between Pekingese and Doberman dogs, has been documented at the site. The reasons for the appearance of this morphological variability within those territories that were part of the Roman Empire are also discussed. Copyright © 2015 John Wiley & Sons, Ltd.     

Can morphospace shed light on cave bear spatial-temporal variation? Population dynamics of Ursus spelaeus from Romualdova pe?ina and Vindija, (Croatia)

Cave bear (Ursus spelaeus) behavioural ecology, as evidenced through population dynamics, is crucial for improving our understanding of why this species went extinct. Despite the fact that the bones of this species have been recovered in very large quantities, allowing for extensive study, fundamental questions regarding its life-ways remain unanswered. We present research using geometric morphometrics (GMM) on molars to investigate population structure based on morphological variation over space and through time. This preliminary work deliberately restricts the geographic catchment area for sampling, allowing for a meaningful appraisal of scale of variation within a spatially conservative framework. Our results demonstrate no significant morphological variation evident temporally and a small but statistically significant degree of shape variation geographically despite the proximity of the study localities. These findings suggest that an accurate quantitative exploration of morphospace may be an important source of evidence on environmental and climatic shifts and the resulting influence on animal morphology.     

Paleolithic occupations of the Göllü Dağ, Central Anatolia,Turkey

Abstract

Systematic archaeological surface reconnaissance of the Göllü Da? volcanic complex from 2007 to 2012 documented more than 230 findspots with Paleolithic artifacts, ranging from isolated finds to extensive and dense scatters of artifacts. Most of the activities represented relate to exploitation of the rich obsidian resources in the region. Paleolithic artifacts are attributed mainly to the Middle Paleolithic based on the presence of Levallois technology but there is a substantial Lower Paleolithic component represented by handaxes and other large bifacial tools. Upper and Epipaleolithic sites and artifacts are scarce or absent in the survey sample. The distributions of handaxes and Levallois elements differ substantially, reflecting differences in site preservation and exposure as well as organization of prehistoric activities. Multiple variants of Levallois are represented but centripetal preferential and unipolar flake production dominate. The frequent co-occurrence of different Levallois forms suggests flexible reduction strategies. Distributions of different classes of artifact across the survey area indicate that the Middle Paleolithic occupations of Göllü Da? were not entirely oriented toward workshop activities.