First Insights into the Technique Used for Heat Treatment of Chert at the Solutrean Site of Laugerie‐Haute,France

The earliest evidence of flint and chert heat treatment was found in the ~21.5–17 ka old European Solutrean culture. The appearance of pyrotechnology as part of the production of stone tools has important implications for our understanding of Upper Palaeolithic technological evolution and the specific adaptations during the last glacial maximum in Europe. However, the techniques and procedures used to heat‐treat rocks during the Solutrean remain poorly understood. No direct archaeological evidence has so far been found and the most promising approach is to understand these techniques by determining the parameters with which flint and chert were heated at that time. In this study, we investigate the heating temperature of 44 heat‐treated laurel‐leaf points from Laugerie‐Haute, using a non‐destructive technique based on infrared spectroscopy. Our results document that most of the artefacts were heated to a narrow interval of temperatures between 250 °C and 300 °C. This indicates a standardized technique that allowed to created similar conditions during successive heating cycles. The implications of these results for our understanding of the technical complexity during the Solutrean must be discussed in the light of different heating techniques used at different places and periods.     

Who brought in the rabbits? Taphonomical analysis of Mousterian and Solutrean leporid accumulations from Gruta do Caldeirão (Tomar,Portugal)

In the Iberian Peninsula, leporids, and specifically rabbits, play a key role in the understanding of hunter-gatherer economies. They appear to have been especially important in the Tardiglacial, when large numbers of small prey animals and of the European rabbit (Oryctolagus cuniculus) in particular, are a ubiquitous feature of faunal assemblages from archaeological sites. Since a large number of non-human predators can also contribute to the formation of such assemblages, the ability to discriminate between bones accumulated by humans and by other kinds of predators is a key prerequisite to their interpretation. On the basis of systematic actualistic studies carried out on modern leporid remains produced by mammalian terrestrial carnivores, nocturnal and diurnal raptors, and humans, we identified diagnostic taphonomic indicators of the different predators. In this paper, the patterns observed on the modern material are applied to the taphonomical analysis of two archaeological samples of rabbit and hare remains from Mousterian and Solutrean layers of Gruta do Caldeirão, a cave site located in Central Portugal. Our results suggest that Eagle Owl (Bubo bubo) were mainly responsible for the Mousterian accumulations, whilst the Solutrean ones were most likely the result of human activity. These data support the notion that, in Iberia, significant reliance on rabbits does not become a feature of subsistence strategies until later Upper Palaeolithic times.     

Investigating the peopling of North America through cladistic analyses of Early Paleoindian projectile points

The initial colonization of North America remains a controversial topic. There is widespread agreement that Clovis and related cultures of the Early Paleoindian period (∼11,500–10,500 BP) represent the first well-documented indications of human occupation, but considerable differences of opinion exist regarding the origins of these cultures. Here, we report the results of a study in which data from a continent-wide sample of Early Paleoindian projectile points were analyzed with cladistic methods in order to assess competing models of colonization as well as several alternative explanations for the variation among the points, including adaptation to local environmental circumstances, cultural diffusion, and site type effects. The analyses suggest that a rapidly migrating population produced the Early Paleoindian projectile point assemblages. They also suggest that the population in question is unlikely to have entered North America from either the Isthmus of Panama or the Midatlantic region. According to the analyses, the Early Paleoindians are more likely to have entered North America via either the ice-free corridor between the Laurentide and Cordilleran ice sheets that is hypothesized to have opened around 12,000 BP, or the Northwest Coast.     

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.     

Ideas no longer written in antler

In the course of the Upper Paleolithic, antler debitage techniques seem to have followed a linear evolution. The earliest one, fracturing by cleaving, appeared during the Aurignacian and is considered by some specialists to be ineffective. According to them, it was not until the invention of the groove and splinter technique during the Gravettian that antler debitage became efficient. Nonetheless, during the Solutrean, fracturing once again became the most common technique, but by splitting. Based on a study of 102 Solutrean pressure tools and experimentations, we reach the conclusion that splitting is a very effective technique that can produce blanks with the same qualities as those made by the groove and splinter technique. The splitting technique was nonetheless excluded in previous studies. We explore the reasons for this and the particularities of the different antler debitage techniques evidenced in the Western Upper Paleolithic.     

Human ecological niches and ranges during the LGM in Europe derived from an application of eco-cultural niche modeling

We apply eco-cultural niche modeling (ECNM), an heuristic approach adapted from the biodiversity sciences, to identify habitable portions of the European territory for Upper Paleolithic hunter-gatherers during the Last Glacial Maximum (LGM), circumscribe potential geographic extents of the Solutrean and Epigravettian technocomplexes, evaluate environmental and adaptive factors that influenced their distributions, and discuss this method's potential to illuminate past human–environment interaction. Our ECNM approach employed the Genetic Algorithm for Rule-Set Prediction (GARP) and used as input a combination of archaeological and geographic data, in conjunction with high-resolution paleoclimatic simulations for this time frame. The archaeological data consist of geographic coordinates of sites dated by Accelerator Mass Spectrometry to the LGM and attributed to the Solutrean and Epigravettian technocomplexes. The areas predicted by ECNM consistently outline the northern boundary of human presence at 22,000–20,000 cal BP. This boundary is mainly determined by climatic constraints and corresponds well to known southern limits of periglacial environments and permafrost conditions during the LGM. Differences between predicted ecological niches and known ranges of the Solutrean and Epigravettian technocomplexes are interpreted as Solutrean populations being adapted to colder and more humid environments and as reflecting influences of ecological risk on geographic distributions of cultures.     

Investigating links between ecology and bifacial tool types in Western Europe during the Last Glacial Maximum

We apply Eco-Cultural Niche Modeling (ECNM), using the Genetic Algorithm for Rule-Set Prediction, to reconstruct the ecological niches exploited by Middle Solutrean and Upper Solutrean populations during the latter stages of Heinrich Event 2 and the early part of the Last Glacial Maximum, respectively. We focus on the Upper Solutrean technocomplex and its regionally distinct styles of hunting weaponry to investigate whether regional cultural variability reflects a link between material culture and ecology. Our analytical approach uses archaeological and geographic data in conjunction with high-resolution paleoclimatic simulations and vegetation reconstructions for the two climatic phases in question. Our results indicate that cultural choices behind the production of specific projectile point types have at some level an ecological basis and are linked to particular environments. We also find that the identified pattern of Upper Solutrean territoriality has an ecological foundation, but that its stylistic expression in the variation of diagnostic armature types is likely a byproduct of cultural drift. We argue that ECNM is an effective means with which to evaluate the paleoecological pertinence of archaeologically defined artifact types and to identify the ecological and cultural mechanisms underlying material culture variability.