Anaïs Vignoles
email: anais.vignoles@u-bordeaux.fr

William E Banks
email: william.banks@u-bordeaux.fr

Laurent Klaric
email: laurent.klaric@cnrs.fr

Masa Kageyama
email: masa.kageyama@lsce.ipsl.fr

Marlon E Cobos
email: marloncobos@ku.edu

Daniel Romero-Alvarez

Investigating relationships between technological variability and ecology in the Middle Gravettian (ca. 32-28 ky cal. BP) in France

Keywords: Middle Gravettian, France, Noaillian, Rayssian, ecological niche modeling, culture-environment relationships

The French Middle Gravettian represents an interesting case study for attempting to identify mechanisms behind the typo-technological variability observed in the archaeological record. Associated with the relatively cold and dry environments of GS.5.2 and 5.1, this phase of the Gravettian is characterized by two lithic typo-technical entities (faciès in French): the Noaillian (defined by the presence of Noailles burins) and the Rayssian (identified by the Raysse method of bladelet production).

The two faciès have partially overlapping geographic distributions, with the Rayssian having a more northern and restricted geographic extension than the Noaillian. Their chronological relationship, however, is still unclear, and interpretations of their dual presence at many sites within the region of overlap are not yet consensual. Nonetheless, the absence of the Raysse method south of the Garonne River suggests that this valley may have separated two different cultural trajectories for which the Rayssian represents an adaptation to environmental conditions different from those associated with Noaillian assemblages south of the Garonne River. The aim of this study is to test this hypothesis quantitatively using ecological niche modeling (ENM) methods. First, we critically evaluate published data to construct inventories of Noaillian and Rayssian archaeological sites. Next, using ENM methods, we estimate the ecological niches associated with the Middle Gravettian north (Noaillian + Rayssian) and south (Pyrenees Noaillian) of the Garonne River, which are then quantitatively evaluated and compared. Results demonstrate that, despite a relatively large degree of similarity, the niches differ significantly from one another in both geographic and environmental dimensions and that the niche associated with the northern Middle Gravettian is broader than that of the Pyrenees Noaillian. We propose that this pattern reflects different technological, subsistence and mobility strategies linked to the development of the Raysse method in the North, which was likely more advantageous in its environmental contexts than technologies employed by contemporaneous populations in the Pyrenees.

Introduction

The Gravettian is an Upper Paleolithic techno-complex (sensu [START_REF] Clarke | Analytical Archaeology[END_REF]) that has been the subject of extensive research since its recognition (e.g. [START_REF] Klima | Aurignacien, Périgordien, Gravettien-Actes des colloques XV et XVI du IXe congrès de l'UISPP[END_REF]Roebroeks et al., 1999;[START_REF] Rigaud | Les industries lithiques du Gravettien du nord de l'Aquitaine dans leur cadre chronologique[END_REF]Rigaud, , 2009;;de las Heras et al., 2013;Otte, 2013;Wojtal et al., 2015). Spanning ca. 34,000-26,000 calibrated years before present (y. cal. BP), its main unifying characteristics are Gravette-style backed blades and bladelets [START_REF] Pesesse | Le Gravettien existe-t-il ? Le prisme du système technique lithiques[END_REF], diagnostic graphic expressions [START_REF] Féruglio | L'art pariétal gravettien, ce qu'il révèle de la société en complément de la culture matérielle[END_REF], as well as a high frequency of burials [START_REF] Henry-Gambier | Comportement des populations d'Europe au Gravettien : pratiques funéraires et interprétations[END_REF] compared to preceding and subsequent archaeological cultures. These common characteristics are observed in sites across Europe, from Portugal to the Don Valley in western Russia (Otte, 2013).

However, the term "Gravettian" groups together a wide variety of cultural traditions, especially concerning lithic and osseous technology (de la [START_REF] De La Peña | Revisión crítica de los conjuntos líticos gravetienses y su contexto arqueológico en la Península Ibérica[END_REF][START_REF] Pesesse | Le Gravettien existe-t-il ? Le prisme du système technique lithiques[END_REF][START_REF] Noiret | De quoi Gravettien est-il le nom ?[END_REF]Goutas, 2013a). This diversity is challenging to explain since it is characterized by disparate data, many of which were obtained with non-modern excavation methods decades ago or differing analytical approaches (de la [START_REF] De La Peña | Sobre la unidad tecnologica del Gravetiense en la peninsula Ibérica : implicaciones para el conocimiento del Paleolitico superior inicial[END_REF][START_REF] Pesesse | Is it still appropriate to talk about the Gravettian? Data from lithic industries in Western Europe[END_REF]. Moreover, sites that date to the same chronological interval but that lack typical Gravettian features (i.e.

Gravette-style points) serve to challenge the definition of this techno-complex (e.g. [START_REF] Morala | La spécialisation des activités : concept de l'archéologue et réalité archéologique ; les données du site gravettien moyen du Callan (Lot-et-Garonne)[END_REF][START_REF] Klaric | La Picardie (Preuilly-sur-Clase, Indre-et-Loire) : neuf ans de fouille sur un gisement rayssien finalement pas si mal conservé ![END_REF]Klaric et al., , 2018)). In Western Europe, various hypotheses have been proposed to explain this diversity, such as differences in site activities (e.g. [START_REF] Laville | The Perigordian V industries in Périgord : typological variations, stratigraphy and relative chronology[END_REF][START_REF] Rigaud | The Gravettian Peopling of Southwestern France[END_REF], the nature of our archaeological definitions (e.g. [START_REF] Touzé | De la signification du Noaillien et du Rayssien[END_REF][START_REF] Pesesse | Is it still appropriate to talk about the Gravettian? Data from lithic industries in Western Europe[END_REF], regionally differentiated populations that did not share the same technological knowledge or traditions (e.g. [START_REF] Klaric | Des armatures variées et des modes de productions variables. Réflexions à partir de quelques exemples issus du Gravettien d'Europe occidentale (France, Portugal, Allemagne)[END_REF], or differential environmental influences (e.g. [START_REF] David | The Noaillian (level 4) assemblages and the Noaillian Culture in Western Europe[END_REF][START_REF] Djindjian | Le Paléolithique supérieur en Europe[END_REF]. Efforts to identify and evaluate the mechanisms-defined as "a constellation of factors and components that through the process of their interaction with one another stimulates the trajectory of a system" (d'Errico & Banks, 2013, p. 374)-that influenced these cultural traditions can aid in assessing these various hypotheses. burin-core from La Picardie, Indre-et-Loire, France (from [START_REF] Klaric | Anciennes et nouvelles hypothèses d'interprétation du gravettien moyen en France : la question de la place des industries à burins du Raysse au sein de la mosaïque gravettienne[END_REF] The chronological relationship between the Noaillian and the Rayssian has yet to be determined with precision. This is due to the fact that very few contextually reliable 14 C ages are associated with these two faciès, and for regions north of the Garonne River the low number of available ages renders any chronological comparison between the two phases uninformative at present [START_REF] Banks | An application of hierarchical Bayesian modeling to better constrain the chronologies of Upper Paleolithic archaeological cultures in France between ca. 32,000-21,000 calibrated years before present[END_REF]. This situation is complicated by the fact that Noailles burins and the Raysse method are frequently found together within the same archaeological layer in the region of overlap. Past and on-going studies suggest that, at many sites, this association is not culturally meaningful due to imprecise excavation methods and/or disturbed stratigraphic contexts (e.g. [START_REF] Klaric | Technical unity of Raysse burins industries in their diachronical context[END_REF][START_REF] Klaric | Regional groups in the European middle Gravettian : a reconsideration of the Rayssian technology[END_REF][START_REF] Vignoles | Le Gravettien du Fourneau du Diable (Bourdeilles, Dordogne) : révision chronoculturelle des ensembles lithiques de la "Terrasse inférieure[END_REF]. However, in a few stratified contexts, the development of the Raysse method is always stratigraphically younger than the Noaillian (e.g., Abri Pataud and Flageolet I sites; [START_REF] David | The Noaillian (level 4) assemblages and the Noaillian Culture in Western Europe[END_REF][START_REF] Rigaud | Le Paléolithique en Périgord : les données du Sud-Ouest sarladais et leurs implications[END_REF][START_REF] Klaric | Technical unity of Raysse burins industries in their diachronical context[END_REF]. An exception to this statement is found at Les Jambes, a site where Noailles burins are described as being stratigraphically above the Raysse burins [START_REF] Célérier | Le gisement périgordien supérieur des "Jambes". Commune de Périgueux (Dordogne)[END_REF]. This configuration, though, remains to be verified. First, the two levels identified by Célérier have been described as part of a slope deposit which raises doubts as to the integrity of the levels. Moreover, stratigraphic projections of artifacts show that the levels defined by Célérier correspond to a single archaeological layer.

Finally, an ongoing reexamination (conducted by A.V) of the site's assemblage demonstrates that most of the "Noailles burins" do not correspond to the classic typological definition. In fact, only one artifact can be considered a typical Noailles burin, while all the others are highly atypical. Technological characterization of the blade/bladelet reduction sequences may provide new data with which to discuss the presence of Gravette points-a class of tool traditionally associated with the Noaillian rather that the Rayssian-at Les Jambes.

Numerous hypotheses have been proposed to explain the co-occurrence of Noaillian and Rayssian materials in the same archaeological level, such as a gradual replacement of the Noaillian by the Rayssian [START_REF] David | The Noaillian (level 4) assemblages and the Noaillian Culture in Western Europe[END_REF][START_REF] Pottier | ): le niveau 4 et l'éboulis 3/4. Etude technologique et typologique de l'industrie lithique[END_REF], differing site activities [START_REF] Laville | The Perigordian V industries in Périgord : typological variations, stratigraphy and relative chronology[END_REF][START_REF] Rigaud | Les industries lithiques du Gravettien du nord de l'Aquitaine dans leur cadre chronologique[END_REF][START_REF] Rigaud | Révision de quelques archéoséquences de référence du Gravettien du nord de l'Aquitaine[END_REF], the use of different typo-technological traditions within a broad regional population [START_REF] Touzé | De la signification du Noaillien et du Rayssien[END_REF] or the result of post-depositional mixing or the inability of old excavation methods to differentiate between discrete occupations [START_REF] Klaric | Technical unity of Raysse burins industries in their diachronical context[END_REF][START_REF] Klaric | Regional groups in the European middle Gravettian : a reconsideration of the Rayssian technology[END_REF][START_REF] Vignoles | Le Gravettien du Fourneau du Diable (Bourdeilles, Dordogne) : révision chronoculturelle des ensembles lithiques de la "Terrasse inférieure[END_REF]. Unfortunately, taphonomic evaluations of individual sites are not yet sufficiently numerous to evaluate these hypotheses adequately [START_REF] Klaric | Technical unity of Raysse burins industries in their diachronical context[END_REF][START_REF] Klaric | Regional groups in the European middle Gravettian : a reconsideration of the Rayssian technology[END_REF][START_REF] Pottier | ): le niveau 4 et l'éboulis 3/4. Etude technologique et typologique de l'industrie lithique[END_REF][START_REF] Agsous | Stratigraphie et sédimentologie de l'abri Pataud (Les Eyzies-de-Tayac[END_REF][START_REF] Michel | L'Aurignacien récent (post-ancien) dans le Sud-Ouest de la France : variabilité des productions lithiques. Révision taphonomique et techno-économique des sites de Caminade-Est, abri Pataud, Roc-de-Combe, Le Flageolet I, La Ferrassie et Combemenue[END_REF][START_REF] Gottardi | La question des faciès au Gravettien : fonctions, traditions ou chronologie ?[END_REF].

With respect to geography, these two archaeological traditions have only partially overlapping distributions (Figure 2). The Noaillian is observed in regions south of the Loire River, as well as a very isolated presence in the Vosges region, with extensions into Cantabrian Spain and the Italian Peninsula. The Rayssian is restricted to a smaller geographic area situated between the Garonne River and the southern portion of the Paris Basin, with extensions into Burgundy and Brittany [START_REF] Klaric | Technical unity of Raysse burins industries in their diachronical context[END_REF][START_REF] Klaric | La réussite d'une production repose sur l'attention prêtée aux détails »: l'exemple des débitages lamellaires par méthode du Raysse (Gravettien moyen, France)[END_REF][START_REF] Touzé | De la signification du Noaillien et du Rayssien[END_REF]. Despite mentions of the presence of Raysse burins at the sites of La Carane-3, Isturitz and Tuto de Camalhot by [START_REF] David | The Noaillian (level 4) assemblages and the Noaillian Culture in Western Europe[END_REF], the presence of the Raysse method south of the Garonne River has not been unequivocally demonstrated: none of these artifacts have been described or pictured, nor do recent technological studies (e.g. Simonet, 2009a) mention them. The demonstration of the Raysse method relies on precise technical criteria and more specifically on the identification of the bladelet component associated with Raysse burin-cores, and [START_REF] David | The Noaillian (level 4) assemblages and the Noaillian Culture in Western Europe[END_REF] did not use such criteria to describe the Late Noaillian (i.e. Rayssian) in these southern contexts. It is also important to point out that look-alike artifacts (faux-amis) have been described at Brassempouy [START_REF] Klaric | Des armatures aux burins : des critères de distinction techniques et culturels à partir des productions lamellaires de quelques sites du Gravettien moyen et récent (France)[END_REF]. The exemples reported by David could therefore be misleading in the same way.

The absence of the Raysse method south of the Garonne River suggests that this valley may have played a role in the separation of the two different technological trajectories. This is also paired with the fact that the Noaillian in the Pyrenees appears to have lasted as long as the entire Middle Gravettian phase (Noaillian and subsequent Rayssian) present north of the Garonne River [START_REF] Touzé | De la signification du Noaillien et du Rayssien[END_REF][START_REF] Klaric | La réussite d'une production repose sur l'attention prêtée aux détails »: l'exemple des débitages lamellaires par méthode du Raysse (Gravettien moyen, France)[END_REF][START_REF] Banks | An application of hierarchical Bayesian modeling to better constrain the chronologies of Upper Paleolithic archaeological cultures in France between ca. 32,000-21,000 calibrated years before present[END_REF]. This pattern suggests that the environment may have played a role in the development of the cultural adaptation that serve to define the Rayssian faciès [START_REF] David | The Noaillian (level 4) assemblages and the Noaillian Culture in Western Europe[END_REF][START_REF] Djindjian | Le Paléolithique supérieur en Europe[END_REF].

Research question and approach

Here, we test the hypothesis that the typo-technological differences observed on either side of the Garonne River valley during the Middle Gravettian reflect the exploitation of different environmental conditions via different technological (i.e. cultural) adaptations. The application of Ecological Niche Modeling (ENM) methods to the archaeological record is one means with which to conduct such a test [START_REF] Banks | The application of Ecological Niche Modeling methods to archaeological data in order to examine Culture-Environment relationships and cultural trajectories[END_REF][START_REF] Banks | Human-climate interaction during the Early Upper Paleolithic: testing the hypothesis of an adaptive shift between the Proto-Aurignacian and the Early Aurignacian[END_REF]. ENM (the terminology employed in this study, cf. [START_REF] Peterson | Species distribution modeling and ecological niche modeling: getting the concepts right[END_REF][START_REF] Warren | In defense of 'niche modeling[END_REF] provides a means for estimating the ecological niches of past hunter-gatherer populations, employing archaeological sites as occurrence data and environmental variables derived from high-resolution paleoclimatic simulations. These data are then used by predictive modeling algorithms to identify sets of environmental parameters associated with known archaeological sites and create an estimation of the presence of suitable environmental conditions (i.e. the ecological niche) across the study area. Niche estimations can be compared with one another in order to characterize and evaluate potential differences between niches (e.g. [START_REF] Warren | Environmental Niche Equivalency versus Conservatism: Quantitative Approaches to Niche Evolution[END_REF]. The use of these tools has been demonstrated to be a valuable approach for assessing cultureenvironment relationships of past hunter-gatherer populations, both synchronically and diachronically (e.g. [START_REF] Banks | Human ecological niches and ranges during the LGM in Europe derived from an application of eco-cultural niche modeling[END_REF][START_REF] Banks | Investigating links between ecology and bifacial tool types in Western Europe during the Last Glacial Maximum[END_REF][START_REF] Banks | Eco-cultural niches of the Badegoulian: Unraveling links between cultural adaptation and ecology during the Last Glacial Maximum in France[END_REF][START_REF] Banks | Human-climate interaction during the Early Upper Paleolithic: testing the hypothesis of an adaptive shift between the Proto-Aurignacian and the Early Aurignacian[END_REF]d'Errico et al., 2017)

Materials and Methods

Conceptual framework of ecological niche modelling

The conceptual framework of ENM is based on [START_REF] Hutchinson | Population studies: Animal ecology and demography[END_REF] definition of the fundamental niche (NF): an n-dimensional hypervolume whose dimensions are the noninteractive environmental variables (i.e. scenopoetic variables) necessary for a species to maintain populations indefinitely without immigrational subsidy. Following Peterson andSoberón (2005, 2012), we consider the Biotic-Abiotic-Mobility framework (BAM, Figure 3) to describe factors constraining geographic distribution of species. The projection of NF in geographic space (G), i.e. the geographic localities corresponding to NF, identifies areas with conditions favorable to the species (A). However, the geographic distribution of a species can be constrained by at least two other types of factors: biotic interactions (B), i.e. the species' positive or negative interactions with other species or resources that are present, and the areas that have been physically accessible to the species over a relevant period of time (M). The intersection of A and B is the potential distributional area (GP), which is the geographic expression of the realized niche (NR) defined by [START_REF] Hutchinson | Population studies: Animal ecology and demography[END_REF]. In this study, we focus on NF, defined solely on the basis of non-interactive variables, following the Eltonian-noise hypothesis, which argues that biotic interactions may often be manifested at fine spatial resolutions and thus may not have a significant or limiting effect on a species' distribution at broad geographic scales [START_REF] Soberón | Grinnellian and Eltonian niches and geographic distributions of species[END_REF]. Finally, the intersection of GP with M defines the occupied distributional area (GO). In environmental space, the intersection between NF and the environments associated with M define the existing fundamental niche (NF*), which is the portion of the fundamental niche that is actually observable in nature [START_REF] Peterson | Species distribution modeling and ecological niche modeling: getting the concepts right[END_REF].

When applied to the archaeological record, the goal is to identify the sets of environmental conditions associated with a cultural trait or with a techno-complex, and evaluate their eventual co-variability through time [START_REF] Banks | The application of Ecological Niche Modeling methods to archaeological data in order to examine Culture-Environment relationships and cultural trajectories[END_REF]. Furthermore, with respect to examinations of culture-environment relationships and cultural adaptations, it is pertinent to evaluate to what extent an archaeological typo-technological complex (archaeological culture) occupied its existing niche (i.e. GO vs. observed distribution).

Data

Archaeological data

Occurrence data consist of the geographic coordinates of archaeological sites where Noaillian and/or Rayssian material culture assemblages have been identified (Figure 4). These data were assembled through a critical examination of the literature, although one must keep in mind that this approach has certain limitations. First, most sites were excavated and studied in the late 19 th and first half of the 20 th century, sometimes in an expeditious manner. Due to the fact that excavated sediments were rarely sieved and often only large, diagnostic tools were kept, many assemblages are biased and do not necessarily contain artifacts that allow the two typo-technological faciès to be reliably recognized, since their diagnostic artifacts are of small size (e.g., Raysse and Picardie bladelets, some Noailles burins, Noailles burins spalls), and/or correspond to flint knapping by-products (e.g., Raysse bladelets, blades with oblique lateralized faceted platforms). As a result, there are numerous sites where one or both of these Middle Gravettian faciès was not initially recognized (e.g., Fourneau du Diable, Laussel or Combe-Saunière I; [START_REF] Klaric | La réussite d'une production repose sur l'attention prêtée aux détails »: l'exemple des débitages lamellaires par méthode du Raysse (Gravettien moyen, France)[END_REF][START_REF] Vignoles | Le Gravettien du Fourneau du Diable (Bourdeilles, Dordogne) : révision chronoculturelle des ensembles lithiques de la "Terrasse inférieure[END_REF] and this is likely the case for many others.

Therefore, the corpus of sites associated with these two archaeological faciès should be considered incomplete at present. Furthermore, many assemblages, even those that were rather well-excavated (piece-plotted artefacts, sieved archaeological sediments, collection of unretouched artifacts) often have not been subjected to recent contextual examinations or typotechnological re-evaluations (e.g., Les Jambes, Le Facteur). This is especially a problem for the bibliographic identification of the Raysse method. Although the Raysse burin type was first described in the 1950s [START_REF] Pradel | Précisions sur les Burins d'Angles et les Burins Plans[END_REF][START_REF] Couchard | La grotte de Bassaler-Nord, près de Brive et la question du Périgordien II en Corrèze[END_REF][START_REF] Movius | Burins avec modification tertiaire du biseau, burins-pointe et burins du Raysse à l'Abri Pataud, Les Eyzies (Dordogne)[END_REF], its function as a core for producing standardized projectile point implements was only demonstrated in the early 2000s [START_REF] Klaric | Un nouveau type d'armature en contexte gravettien et son mode de production sur les burins du Raysse (la Picardie, commune de Preuilly-sur-Claise, Indre-et-Loire)[END_REF][START_REF] Lucas | À propos des burins du Raysse du Flageolet I (Dordogne, France)[END_REF]. It is therefore necessary to reconsider, from a technological standpoint, all previously identified Raysse burins and to identify the presence of the associated bladelet component in order to avoid attributing archaeological levels to this faciès on the basis of look-alike (faux-amis) artifacts [START_REF] Klaric | Technical unity of Raysse burins industries in their diachronical context[END_REF][START_REF] Klaric | Des armatures aux burins : des critères de distinction techniques et culturels à partir des productions lamellaires de quelques sites du Gravettien moyen et récent (France)[END_REF].

Another problem is the unequal definition of the Noaillian (i.e. sole presence of Noailles burins in an assemblage) and the Rayssian [START_REF] Touzé | De la signification du Noaillien et du Rayssien[END_REF]. The latter's technical system is relatively well-described across its area of expression [START_REF] Lucas | Les industries lithiques du Flageolet I (Dordogne) : Approche économique, technologique, fonctionnelle et analyse spatiale[END_REF][START_REF] Lucas | À propos des burins du Raysse du Flageolet I (Dordogne, France)[END_REF][START_REF] Klaric | Technical unity of Raysse burins industries in their diachronical context[END_REF][START_REF] Klaric | La réussite d'une production repose sur l'attention prêtée aux détails »: l'exemple des débitages lamellaires par méthode du Raysse (Gravettien moyen, France)[END_REF][START_REF] Pottier | ): le niveau 4 et l'éboulis 3/4. Etude technologique et typologique de l'industrie lithique[END_REF]Pottier, , 2006;;[START_REF] Guillermin | Les Fieux : une occupation gravettienne du Causse quercinois[END_REF][START_REF] Touzé | Caractérisation de la "méthode du Raysse" à Bassaler-nord et au Raysse (Corrèze, France)[END_REF][START_REF] Touzé | De la signification du Noaillien et du Rayssien[END_REF][START_REF] Gottardi | La question des faciès au Gravettien : fonctions, traditions ou chronologie ?[END_REF][START_REF] Sarrazin | Les burins-nucléus du Raysse de la collection des Morts (Grotte des Morts, Brive-la-Gaillarde). Interprétation du schéma opératoire et analyse des séquences[END_REF][START_REF] Sarrazin | Plasenn-al-Lomm et la stabilité du système technique rayssien[END_REF]. Variability in the use of the Raysse method has been attributed mainly to blank selection, the availability of suitable lithic raw materials, levels of technological expertise and contingencies of the reduction sequence [START_REF] Klaric | Des armatures variées et des modes de productions variables. Réflexions à partir de quelques exemples issus du Gravettien d'Europe occidentale (France, Portugal, Allemagne)[END_REF][START_REF] Klaric | La réussite d'une production repose sur l'attention prêtée aux détails »: l'exemple des débitages lamellaires par méthode du Raysse (Gravettien moyen, France)[END_REF][START_REF] Klaric | Levels of flintknapping expertise and apprenticeship during the Mid-Upper Palaeolithic: several illustrative examples from the Early and Late Aurignacian and Middle Gravettian[END_REF]. To the contrary, the technical system associated with Noailles burins has only been the subject of isolated studies in the Landes (e.g. [START_REF] Klaric | Technical unity of Raysse burins industries in their diachronical context[END_REF]Simonet, 2009a[START_REF] Simonet | La Pointe des Vachons : nouvelles approches d'un fossile directeur controversé du Gravettien à partir des exemplaires du niveau IV de la grotte d'Isturitz (Pyrénées-Atlantiques, France) et des niveaux 4 des abris 1 et 2 des Vachons (Charente, France)[END_REF][START_REF] Lacarrière | Vers une redéfinition des occupations gravettiennes de la grotte d'Isturitz (Pyrénées-Atlantiques, France) : révision critique des collections "anciennes" par l'approche intégrée des données lithiques, fauniques et de l'industrie osseuse[END_REF], the Pyrenees piedmont and plateau (e.g. [START_REF] Foucher | Les industries lithiques du complexe Gravettien-Solutréen dans les Pyrénées : techno-typologie et circulation des matières siliceuses de part et d'autre de l'axe Pyrénées-Cantabres[END_REF]Simonet, 2009a), and to lesser extents the Perigord region [START_REF] Lucas | Les industries lithiques du Flageolet I (Dordogne) : Approche économique, technologique, fonctionnelle et analyse spatiale[END_REF][START_REF] Pottier | ): le niveau 4 et l'éboulis 3/4. Etude technologique et typologique de l'industrie lithique[END_REF] and the southern Paris Basin [START_REF] Kildea | Le Gravettien de la vallée du Cher : le site de la Croixde-Bagneux à Mareuil-sur-Cher (Loir-et-Cher, France)[END_REF], thus rendering evaluations of its homogeneity difficult. Typo-technological studies conducted on assemblages from Cantabrian Spain (e.g. de la Peña-Alonso, 2011), the French Mediterranean coast (e.g. Onoratini, 1982;[START_REF] Santaniello | Il Gravettiano dell'Italia tirrenica nel contesto mediterraneo: definizione delle strategie di insediamento e mobilità attraverso lo studio delle materie prime e delle industrie litiche[END_REF], and the Italian peninsula (e.g. Onoratini, 1982;[START_REF] Angevin | Le Paléolithique supérieur dans le sud du Bassin parisien à la lumière des découvertes récentes : faits attendus, faits nouveaux[END_REF][START_REF] Aranguren | Territorial exploitation in the Tyrrhenian Gravettian Italy: The casestudy of Bilancino (Tuscany)[END_REF][START_REF] Simonet | Les armatures lithiques du Gravettien à burins de Noailles du niveau G de la grotte des Enfants (Balzi Rossi, Ligurie, Italie): premiers éléments d'enquête[END_REF][START_REF] Santaniello | Il Gravettiano dell'Italia tirrenica nel contesto mediterraneo: definizione delle strategie di insediamento e mobilità attraverso lo studio delle materie prime e delle industrie litiche[END_REF][START_REF] Santaniello | Le Gravettien entre l'Italie et la France : nouvelles données sur l'industrie lithique de l'Abri Mochi (Balzi Rossi, Italie)[END_REF] have employed different methodological approaches for characterizing reduction sequences (i.e. chaînes opératoires) and typologies, with a few exceptions (e.g. [START_REF] Simonet | Les armatures lithiques du Gravettien à burins de Noailles du niveau G de la grotte des Enfants (Balzi Rossi, Ligurie, Italie): premiers éléments d'enquête[END_REF], thus making comparisons to sites studied via the methods traditionally used in France difficult. An additional obstacle is related to this record's chronology. Noailles burins have been recovered from Cantabrian contexts that are contemporaneous with the Late Aurignacian in southwestern France, as well as contexts that extend into the Solutrean (de la Peña-Alonso, 2011, p. 681). Noailles burin contexts in Italy are also interpreted as being younger than those in France [START_REF] Touzé | De la signification du Noaillien et du Rayssien[END_REF], but the majority of their associated radiocarbon ages were produced decades ago (non-AMS) and evaluations of their archaeological association are lacking, thus rendering any comparison to the French archaeological record unreliable at present. Taking into account these limitations, we constrain our analysis to the comparison of two adjacent regions that are thought to represent coherent territories during the Middle Gravettian:

1) the Pyrenees piedmont and plateau, based on assemblages that are regionally coherent with respect of lithic typo-technology (i.e. contexts that contain Noailles burins and in which the Raysse method is absent) and raw material circulation for the entirety of the Middle Gravettian [START_REF] Foucher | Le Gravettien des Pyrénées[END_REF][START_REF] Foucher | Synthèse chrono-culturelle sur le Gravettien des Pyrénées : constat et réflexions sur la stabilité régionale des traditions techniques[END_REF]Simonet, 2009a[START_REF] Simonet | Gravettians at Brassempouy (Landes, France), 30,000 BP: a semisedentary territorial organization[END_REF][START_REF] Banks | An application of hierarchical Bayesian modeling to better constrain the chronologies of Upper Paleolithic archaeological cultures in France between ca. 32,000-21,000 calibrated years before present[END_REF], and 2) the area constrained along its southern margin by the Garonne River Valley and by the most northerly sites where the "Raysse method" has been observed [START_REF] Klaric | La réussite d'une production repose sur l'attention prêtée aux détails »: l'exemple des débitages lamellaires par méthode du Raysse (Gravettien moyen, France)[END_REF]. The latter territory is characterized by both the Noaillian and the Rayssian faciès, and the lack of precision, at present, concerning their chronological relationship required that we group them together, mirroring the approach employed by [START_REF] Banks | An application of hierarchical Bayesian modeling to better constrain the chronologies of Upper Paleolithic archaeological cultures in France between ca. 32,000-21,000 calibrated years before present[END_REF].

In an effort to retain only sites for which a reliable techno-typological attribution could be made, published studies were carefully evaluated with respect to the pertinence of the data they contained (see Appendix). A source was considered pertinent if it provided precise counts of tool types based on the most recent typo-technological definitions (e.g. for the "Noailles burin" type: Bardon & Bouyssonies, 1903;Tixier, 1958; for "Picardie bladelet" type and "Raysse burin-core": [START_REF] Klaric | Un nouveau type d'armature en contexte gravettien et son mode de production sur les burins du Raysse (la Picardie, commune de Preuilly-sur-Claise, Indre-et-Loire)[END_REF][START_REF] Klaric | Technical unity of Raysse burins industries in their diachronical context[END_REF][START_REF] Klaric | La réussite d'une production repose sur l'attention prêtée aux détails »: l'exemple des débitages lamellaires par méthode du Raysse (Gravettien moyen, France)[END_REF], preferably supplemented with artifact drawings or photos. We also included personal observations made during the course of on-going and yet-to-be-published studies (L. Klaric and A. Vignoles). We, thus, did not retain sites for which one or both faciès were only suspected to be present in order to avoid potentially aberrant attributions based on look-alike artifacts. For example, "Raysse burins" reported in Brassempouy or Le Gratadis have been shown to not be actual Raysse burin-cores aimed at the production of La Picardie bladelets [START_REF] Klaric | Technical unity of Raysse burins industries in their diachronical context[END_REF][START_REF] Klaric | Des armatures aux burins : des critères de distinction techniques et culturels à partir des productions lamellaires de quelques sites du Gravettien moyen et récent (France)[END_REF]. Bearing this in mind, we did not retain sites where Raysse burins were only mentioned with no demonstration of the presence of the Raysse method (e.g. Abri André Ragout; [START_REF] David | The Noaillian (level 4) assemblages and the Noaillian Culture in Western Europe[END_REF]. Also, sites where Raysse burins are depicted in published drawings [START_REF] Klaric | Technical unity of Raysse burins industries in their diachronical context[END_REF] but that have not been confirmed by us via direct observation and where the presence of the associated bladelet component has not yet been evaluated, such as the site of Roc de Gavaudun in Lot-et-Garonne or Lespaux shelter in Gironde [START_REF] Monméjean | Le Périgordien supérieur à burins de Noailles du Roc de Gavaudun (Lot-et-Garonne)[END_REF][START_REF] Krtolitza | Un gisement du Gravettien à burins de Noailles en Gironde, l'abri Lespaux à Saint-Quentin-de-Baron[END_REF], were not included. Finally, we also eliminated sites for which the presence of Raysse burin cores is not consensual, such as Chamvres in Yonne [START_REF] Klaric | Technical unity of Raysse burins industries in their diachronical context[END_REF]vs. Sarrazin, 2018). In the same vein, we did not retain sites where reported "Noailles burins" have been demonstrated to be look-alike artifacts, such as the site of Les Jambes (ongoing examination by A.V.). Moreover, sites where Noailles burins are all atypical, such as Peutille in Lot-et-Garonne [START_REF] Morala | Périgordien et Aurignacien en Haut-Agenais : étude d'ensembles lithiques[END_REF], or sites where only one or two Noailles burins are reported and their presence is not supported by published drawings, such as La Verpillière I cave in Saône-et-Loire [START_REF] Floss | Le Paléolithique supérieur ancien en Bourgogne du sud[END_REF], were eliminated from consideration.

In the end, we retained 74 sites for our analysis. North of the Garonne River, there are 9

Rayssian sites, 40 Noaillian sites, as well as 13 additional sites that yield both faciès. In the Pyrenees piedmont and plateau, 12 Noaillian sites were retained (Figure 4; Table 1).

Table 1. Sites retained or rejected based on a critical review of the literature, along with their geographic coordinates and references. A site was assigned to a specific data set or rejected based on criteria detailed in the Appendix. Geographic coordinates correspond to the commune (i.e. town administrative territory)

in which the site is localized. Although these coordinates do not necessarily correspond to the site itself, their resolution is more than adequate considering the 11.5 km-grid resolution of the environmental data.

Environmental predictors

In order to employ the appropriate environmental data, it is paramount to determine accurately the precise chronology of the target archaeological culture so that it can be correlated to the appropriate climatic event or events [START_REF] Banks | Constructing chronologies for the late Middle Paleolithic and Upper Paleolithic: limitations and means to overcome them[END_REF][START_REF] Banks | An application of hierarchical Bayesian modeling to better constrain the chronologies of Upper Paleolithic archaeological cultures in France between ca. 32,000-21,000 calibrated years before present[END_REF]. Based on the results presented by [START_REF] Banks | An application of hierarchical Bayesian modeling to better constrain the chronologies of Upper Paleolithic archaeological cultures in France between ca. 32,000-21,000 calibrated years before present[END_REF], the Middle Gravettian begins between the latter part of Greenland Interstadial 5.2 (GI 5. have not been dated or are not associated with reliable dates, we must assume that all sites date to some point between ca. 32 and 28.5 ky cal. BP (after [START_REF] Banks | An application of hierarchical Bayesian modeling to better constrain the chronologies of Upper Paleolithic archaeological cultures in France between ca. 32,000-21,000 calibrated years before present[END_REF]. Second, the chronological resolution of individual radiocarbon measurements does not allow us to determine whether a specific dated occupation is associated with a specific Interstadial or Stadial (GI 5.1 or GS 5.1 for example). This limitation makes it impossible to create separate occurrence data sets such that correspond to specific Stadial or Interstadial events. Therefore, we choose environmental data such that correspond to stadial conditions since those were present during the majority of the period concerned by this study (ca. 2.5 ky for GS 5.2 and 5.1 combined vs. ca. 0.5 ky for GI 5.1).

We employed as environmental background climatic variables derived from a highresolution paleoclimatic simulation obtained with the Atmospheric Global Circulation Model (AGCM) LMDZ5A [START_REF] Hourdin | Impact of the LMDZ atmospheric grid configuration on the climate and sensitivity of the IPSL-CM5A coupled model[END_REF]. It was run with a zoomed grid permitting a spatial resolution of ca. 50 km over Europe, following [START_REF] Sima | Imprint of North-Atlantic abrupt climate changes on western European loess deposits as viewed in a dust emission model[END_REF][START_REF] Sima | Modeling dust emission response to North Atlantic millennial-scale climate variations from the perspective of East European MIS 3 loess deposits[END_REF]. We used the same coastlines and ice-sheet configuration as [START_REF] Sima | Imprint of North-Atlantic abrupt climate changes on western European loess deposits as viewed in a dust emission model[END_REF][START_REF] Sima | Modeling dust emission response to North Atlantic millennial-scale climate variations from the perspective of East European MIS 3 loess deposits[END_REF], i.e. those corresponding to the Last Glacial Maximum (LGM; Figure 4). Atmospheric greenhouse gas concentrations were also left at their LGM values (CO2 = 185 ppm, CH4 = 350 ppb, N2O = 200 ppb). The orbital parameters are set to 32 ky cal. BP [START_REF] Berger | Long-term variations of daily insolation and quaternary climatic changes[END_REF], which correspond to the beginning of GS 5.2. Initial boundary conditions for prescribed sea surface temperatures (SSTs) and sea ice cover were computed with the coupled atmosphere-ocean general circulation model IPSLCM4 [START_REF] Marti | Key features of the IPSL ocean atmosphere model and its sensitivity to atmospheric resolution[END_REF]. This model was obtained by setting forcing and boundary conditions of the PMIP3 LGM experiment described in [START_REF] Alkama | Impact of a realistic river routing in coupled ocean-atmosphere simulations of the Last Glacial Maximum climate[END_REF] and [START_REF] Kageyama | Mid-Holocene and Last Glacial Maximum climate simulations with the IPSL model-part I: comparing IPSL_CM5A to IPSL_CM4[END_REF] to 32 ky cal. BP, thus producing an enhanced seasonal cycle of incoming insolation and surface temperatures in the Northern hemisphere.

Results were further downscaled to a spatial resolution of 11.5 km via the spline interpolation available in ArcMap 10.7.1. The simulated variables employed in this analysis are mean annual precipitation, warmest month temperature and coldest month temperature. We did not use elevation as a covariate in this process. Elevation is usually considered to be a proxy for temperature, because these two variables are highly correlated. Moreover, elevation is also taken into account during the paleoclimatic simulation process. These reasons make it a redundant and non-informative variable for the niche analyses presented here.

Ecological niche modeling 2.3.1. Modeling preparation

Prior to estimating niches, we analyzed and filtered the occurrence datasets to reduce potential spatial biases. First, we trimmed duplicate site occurrences from each grid-cell, so that a grid-cell contained only a single occurrence point, thus ensuring that the training and testing occurrence datasets would be spatially unique (i.e., no shared occurrences). Next, we thinned the occurrence datasets to eliminate clusters of sites, thereby preventing oversampling of environmental conditions from certain areas (e.g., the northern Aquitaine area) and reducing potential spatial autocorrelation [START_REF] Anderson | Species-specific tuning increases robustness to sampling bias in models of species distributions: an implementation with Maxent[END_REF][START_REF] Boria | Spatial filtering to reduce sampling bias can improve the performance of ecological niche models[END_REF]. This consisted of eliminating occurrences such that the minimum distance between any pair of occurrence points was twice the grid resolution, i.e. ca. 23 km. This step was performed manually using the "Measure line" tool in QGIS 2.18.28. The final datasets consisted of 10 occurrence points for the Noaillian in the Pyrenees piedmont and plateau, and 20 occurrences for the Middle Gravettian north of the Garonne River (Noaillian and Rayssian combined).

The definition of a calibration area (M) relies on biogeographic assumptions (Peterson et al., 2011 p. 135;[START_REF] Barve | The Crucial Role of the Accessible Area in Ecological Niche Modeling and Species Distribution Modeling[END_REF]. To define (M) for Middle Gravettian hunter-gatherers in our region of study (Figure 4), we assume that these populations could not live in regions in close proximity to ice sheets, and that they could have occupied areas exposed by the period's lower sea levels. We therefore masked the environmental variables with coast lines 90 m below present day sea level [START_REF] Waelbroeck | Sea-level and deep water temperature changes derived from benthic foraminifera isotopic records[END_REF][START_REF] Siddall | Sea-level fluctuations during the last glacial cycle[END_REF], as well as with LGM ice sheet coverage reconstructions in the Alps, Pyrenees and the Massif Central [START_REF] Ehlers | Quaternary Glaciations -Extent and Chronology, Part I: Europe[END_REF]. While these reconstructions slightly over-estimate ice coverage for ca. 32 ky cal. BP, they still serve as an adequate proxy since the areas in question would have been characterized by cold and dry, if not periglacial, conditions during the corresponding stadials and HE.

Furthermore, based on the nature of raw material (flint) circulation in the Pyrenees region [START_REF] Foucher | Le Gravettien des Pyrénées[END_REF][START_REF] Simonet | Gravettians at Brassempouy (Landes, France), 30,000 BP: a semisedentary territorial organization[END_REF], we allowed the predictive modeling architecture to extrapolate into the regions of Cantabria and Catalonia. Finally, the Rhône River Valley in the East may have served to limit the movements of hunter-gatherer populations (no raw material circulation across the valley, cf. [START_REF] Santaniello | Il Gravettiano dell'Italia tirrenica nel contesto mediterraneo: definizione delle strategie di insediamento e mobilità attraverso lo studio delle materie prime e delle industrie litiche[END_REF]. Furthermore, recent geomorphological studies show that the lower and middle Rhône Valley, as well as the Mediterranean continental shelf, likely consisted of a desert, with deflation-related landforms (e.g., yardangs, pans, desert pavements) and sand deposits (dunes, sand ramps) surrounded by loess accumulations during the coldest events of the Last Glacial period [START_REF] Bosq | Last Glacial aeolian landforms and deposits in the Rhône Valley (SE France): Spatial distribution and grain-size characterization[END_REF]. However, the presence of Noailles burins and Gravette points to the east indicates that they were permeable barriers. Thus, we included in our (M) coastal regions of Liguria, Tuscany, Lazio and Campania in presentday Italy where Noailles burins are observed in the archaeological record (Palma di Cesnola, 1991;[START_REF] Touzé | De la signification du Noaillien et du Rayssien[END_REF]. This step was performed with QGIS 2.18.28.

Model calibration and selection

Model calibration and selection were performed using the kuenm R package (Cobos et al., 2019a), which employs Maxent 3.4 [START_REF] Phillips | Maximum entropy modeling of species geographic distributions[END_REF][START_REF] Phillips | Opening the black box: an open-source release of Maxent[END_REF]. In R 3.6.1 (R Core Team, 2019), we created a total of 448 candidate models for each occurrence dataset using distinct parameter settings resulting from the combination of 16 regularization multiplier values, 7

response types representing all possible combinations of the three feature classes (linear, quadratic and product), and four sets of environmental predictors derived from all possible combinations of the three paleoclimatic variables, following [START_REF] Cobos | An Exhaustive Analysis of Heuristic Methods for Variable Selection in Ecological Niche Modeling and Species Distribution Modeling[END_REF]. Threshold and hinge feature classes were not used in order to reduce model complexity and overfitting.

The kuenm package allows the evaluation of statistical significance via partial ROC measures [START_REF] Peterson | Rethinking receiver operating characteristic analysis applications in ecological niche modeling[END_REF], omission rates based on a maximum allowed error (E = 5%, user defined; [START_REF] Anderson | Evaluating predictive models of species' distributions: criteria for selecting optimal models[END_REF][START_REF] Peterson | Rethinking receiver operating characteristic analysis applications in ecological niche modeling[END_REF], and model complexity by means of the Akaike information criterion corrected for small sample sizes (AICc; [START_REF] Warren | Ecological niche modeling in Maxent: the importance of model complexity and the performance of model selection criteria[END_REF]. For the retention of the best performing models among those that were statistically significant, we selected those with omission rates lower than E and of those we retained only the models with ΔAICc values lower than two (i.e. ΔAICc = AICci -AICcmin, where AICci is the AICc of the ith model and AICcmin is the lowest AICc among all significant models for which omission rates are below 5%).

Creation of final models and model comparisons

Using kuenm, we created final models within (M) using the parameter settings selected after model calibration (Table 2). As more than one "best parameter" setting was used to create the final models for the Pyrenees Noaillian, we created a consensus model of all results across all parameterizations by calculating a median model, following [START_REF] Cobos | Assessment and representation of variability in ecological niche model predictions[END_REF]. We also calculated the range from these final models as a variability index. cells with suitability scores that fell within the bottom 5% of all values from grid cells that contained an occurrence point [START_REF] Peterson | Rethinking receiver operating characteristic analysis applications in ecological niche modeling[END_REF]. Subsequently, the remaining range of suitability scores were classified as low, medium or high suitability using equal intervals in QGIS 2.18.28.

Model comparisons were performed in both geographic and environmental dimensions.

To compare the geographic projections of the niches, we used the background similarity and identity tests [START_REF] Warren | Environmental Niche Equivalency versus Conservatism: Quantitative Approaches to Niche Evolution[END_REF][START_REF] Warren | ENMTools: Analysis of niche evolution using niche and distribution models[END_REF], which quantify the similarity / identity between two predictions by measuring their geographic overlap and then comparing the result to a null distribution. The two metrics recommended for such comparisons are Schoener (1968)'s statistic D for niche overlap and the similarity statistic I. They range from 0 (no similarity / not identical) to 1 (total similarity / identical) and are obtained via the comparison of the two empirical niche predictions. These measured metrics are then compared to those obtained from 1000 sets of null niche predictions produced using occurrences randomly sampled from the environmental background available in the calibration area. The difference between the two predictions is deemed to be significant if the empirical value falls below the 5% limits of the null distribution. To compare niches in environmental space, we used NicheA [START_REF] Qiao | NicheA: creating virtual species and ecological niches in multivariate environmental scenarios[END_REF]. We employed a three-dimensional environmental background using the three paleoclimatic variables to develop minimum volume ellipsoid (MVE) niche estimations, with a precision of 0.01, for the Pyrenees Noaillian and the northern Middle Gravettian (Figure 4).

We measured the volume of each ellipsoid and calculated the level of environmental overlap between them using the Jaccard index [START_REF] Qiao | NicheA: creating virtual species and ecological niches in multivariate environmental scenarios[END_REF][START_REF] Qiao | Accessible areas in ecological niche comparisons of invasive species: Recognized but still overlooked[END_REF].

Results

Niche predictions

The northern Middle Gravettian niche estimation (Figure 5a) displays high suitability scores in the northern Aquitaine Basin, the southern Paris Basin, and low-to-medium suitability for the western Italian coast, northwestern Alps piedmont, southern Landes and Western Pyrenees, Brittany, and southern Britain. The site of Hautmougey has the lowest suitability score of all the occurrence points, and this is likely because it is situated in the northeastern portion of the study region and is isolated from the other sites. This is likely the result of less intensive archaeological research in this region relative to others (e.g., Southwestern France, southern Paris Basin; [START_REF] Angevin | Le Paléolithique supérieur dans le sud du Bassin parisien à la lumière des découvertes récentes : faits attendus, faits nouveaux[END_REF]. The Garonne River Valley is characterized by a low level of suitability with the exception of a narrow corridor that connects the high suitability areas in northern Aquitaine to the regions of medium suitability situated in the southern Landes and Western Pyrenees. Finally, the geographic extent of the northern Middle Gravettian niche prediction corresponds closely to the geographic distribution of the occurrence data.

The Pyrenees Noaillian niche prediction (Figure 5b) is geographically extensive and is significantly larger than the distribution of archaeological occurrence data. The estimated niche displays continuous high suitability scores from the coast of Cantabrian Spain up to southern Britain. The lowest predicted occurrence point is that of the site of La Carane-3, and all other sites from the central Pyrenees are located in areas with low to medium suitability scores.

Variability maps indicate that the northern Middle Gravettian model is probably more reliable than that of the Pyrenees Noaillian (Figure 5c and5d). The northern Middle Gravettian variability map displays few and relatively small areas with a range higher than 0.3. The highest suitability ranges occur in Brittany and southern Britain, the Landes platform area, the Massif Central as well as the northern Alps. The Pyrenees Noaillian variability map, however, shows variability ranges higher than 0.3 in areas along the Mediterranean coasts, the Eastern side of the Pyrenees, the Massif Central, as well as along the Atlantic coast and in the Landes periglacial desert area. The suitability estimates in these areas should therefore be considered less reliable since they can vary substantially between models.

Niche comparisons

The Pyrenees Noaillian and the northern Middle Gravettian niches are highly similar in geographic space (Figure 6). However, their differences are significant and they are significantly less similar than would be expected by chance (D metric: North vs. Pyrenees: p = 0.03; Pyrenees vs. North: p = 0.006; I metric: North vs. Pyrenees: p = 0.029; Pyrenees vs. North: p = 0.007; for a statistical significance achieved if p < 0.05; Figure 6). With respect to environmental dimensions, our analysis shows that the niches overlap significantly (MVE overlap volume = 1.110, which corresponds to 97% of the Pyrenees Noaillian ellipsoid volume and 7% of the Northern Middle Gravettian ellipsoid volume; Figure 7). Comparisons demonstrate that the Pyrenees Noaillian niche is smaller and less broad than that of the northern Middle Gravettian, and is primarily contained within the latter (Figure 7). It is worth noting, however, that a small portion of the Pyrenees Noaillian ellipsoid falls outside of the northern

Discussion

The fact that the northern Middle Gravettian niche is significantly broader than that of the Pyrenees Noaillian suggests that the development of the Raysse method is linked to the exploitation of a significantly expanded niche composed of colder, drier conditions that correspond to more open landscapes and associated large mammal prey species. Available archaeological data support this hypothesis. The Raysse method is a highly standardized reduction process that can be applied to a wide variety of blanks, from blades to thick flakes produced during various stages of the blade reduction sequences or other less standardized reduction sequences (e.g., production of flakes or blade-like flakes). The bladelets produced with the Raysse method did not require further intensive modification due to their standardized morphology. Furthermore, if a problem was encountered during the final stages of their production, only minimal investment was needed to produce a new or replacement bladelet [START_REF] Klaric | Un nouveau type d'armature en contexte gravettien et son mode de production sur les burins du Raysse (la Picardie, commune de Preuilly-sur-Claise, Indre-et-Loire)[END_REF][START_REF] Klaric | Des armatures variées et des modes de productions variables. Réflexions à partir de quelques exemples issus du Gravettien d'Europe occidentale (France, Portugal, Allemagne)[END_REF][START_REF] Klaric | Technical unity of Raysse burins industries in their diachronical context[END_REF][START_REF] Klaric | Anciennes et nouvelles hypothèses d'interprétation du gravettien moyen en France : la question de la place des industries à burins du Raysse au sein de la mosaïque gravettienne[END_REF][START_REF] Klaric | La réussite d'une production repose sur l'attention prêtée aux détails »: l'exemple des débitages lamellaires par méthode du Raysse (Gravettien moyen, France)[END_REF]. This highly standardized bladelet production system served to create end-products that could be easily transformed into armatures (a French term commonly used in technological and functional studies to designate either the lithic point hafted on the tip/head of a projectile or the lithic implements hafted laterally on a projectile's foreshaft) that were likely part of a composite and readily maintainable hunting weaponry toolkit. Such a technological adaptation is commonly observed in highly mobile hunter-gatherers that operate in landscapes where access to resources needed to maintain weaponry is unpredictable [START_REF] Binford | Forty-seven trips. A case study in the character of archaeological formation processes[END_REF][START_REF] Bleed | The Optimal Design of Hunting Weapons: Maintainability or Reliability[END_REF]. The importance placed on producing highly standardized components for a maintainable and curated hunting toolkit is further supported by the emphasis that appears to have been placed on transmitting and maintaining this technique [START_REF] Klaric | La réussite d'une production repose sur l'attention prêtée aux détails »: l'exemple des débitages lamellaires par méthode du Raysse (Gravettien moyen, France)[END_REF][START_REF] Klaric | Levels of flintknapping expertise and apprenticeship during the Mid-Upper Palaeolithic: several illustrative examples from the Early and Late Aurignacian and Middle Gravettian[END_REF]. This has been inferred from the numerous technical details that one must take into account when using the Raysse method to replicate La Picardie bladelet blanks, and this is further supported by the frequent presence of unretouched flint knapping debris and retouched objects that appear to have been produced by apprentices or individuals who did not completely master the intricacies of the method [START_REF] Klaric | La réussite d'une production repose sur l'attention prêtée aux détails »: l'exemple des débitages lamellaires par méthode du Raysse (Gravettien moyen, France)[END_REF][START_REF] Klaric | Levels of flintknapping expertise and apprenticeship during the Mid-Upper Palaeolithic: several illustrative examples from the Early and Late Aurignacian and Middle Gravettian[END_REF].

The opposite appears to have been the case in the Pyrenees, where armature forms are more diverse: Gravette points, microgravettes points, bi-truncated backed bladelets, and simple backed implements made from blades or bladelets [START_REF] Klaric | Technical unity of Raysse burins industries in their diachronical context[END_REF]Simonet, 2009aSimonet, , 2011b[START_REF] Simonet | Gravettians at Brassempouy (Landes, France), 30,000 BP: a semisedentary territorial organization[END_REF].

While these armature types were made from straight blade or bladelet blanks, the latter do not need to be highly standardized and can be obtained from a variety of reduction methods.

Intensive retouch is all that is necessary to transform an initial blank into one of these armature types (e.g., Gravettes points broken during fabrication indicate that the blank's width can be reduced up to 50%; Klaric, 2003, p. 257;Simonet, 2009a, fig. 21). The higher typological diversity of armatures in the Pyrenees may reflect a higher degree of variability in how these points were integrated into weapon systems (e.g., axial points vs. laterally mounted elements) used by these populations. These different technological strategies for producing hunting equipment between the northern Middle Gravettian and the Pyrenees Noaillian archaeological records are likely related to differences in targeted medium to large prey species and, in turn, the subsistence strategies and mobility patterns employed to exploit them.

Faunal data indicate that populations in the Pyrenees hunted a variety of animals, such as reindeer, bovids, horse, chamois, bison, deer and fox, whereas northern groups relied principally on reindeer [START_REF] Lacarrière | Les ressources cynégétiques au Gravettien en France : acquisition et modalités d'exploitation des animaux durant la phase d'instabilité climatique précédant le dernier maximum glaciaire[END_REF]. This fact does not necessarily indicate that the availability of prey species was different between these two regions (Lacarrière, 2015, p. 347), but it is worth noting that the smaller Pyrenees niche is associated with a more diverse spectrum of prey species. Thus, it would appear that the Pyrenees piedmont plateau and plains, with its more reduced range of environmental conditions, contained a wide variety of prey species that, as indicated by seasonality data [START_REF] Lacarrière | Les ressources cynégétiques au Gravettien en France : acquisition et modalités d'exploitation des animaux durant la phase d'instabilité climatique précédant le dernier maximum glaciaire[END_REF], were present throughout the year. These data are consistent with inferred Gravettian occupation of the region, which is dominated by small, specialized sites (e.g., Tercis, Gatzarria) situated some distance from larger aggregation sites (e.g., Isturitz, Brassempouy), as well as an exploitation of predominantly local lithic raw materials [START_REF] Simonet | Gravettians at Brassempouy (Landes, France), 30,000 BP: a semisedentary territorial organization[END_REF]. Pyrenees populations, thus, were likely logistically mobile with a well-organized exploitation of resources within a relatively restricted region and narrow ecological niche. The high prey species diversity could therefore be the result of a more generalized hunting strategy within a reduced territory. In this framework, armature diversity could be interpreted as an adaptation to the exploitation of a more diverse prey species spectrum within a smaller and more rugged territory, allowing hunters to easily adapt to different situations by changing their hunting weaponry (e.g. prey type, topography etc.).

To the north, in contrast, the wider range of environmental conditions (i.e., broader ecological niche) exploited by the northern Middle Gravettian populations would suggest a higher degree of mobility than is observed in the Pyrenees since the main prey species identified in northern archaeological assemblages is reindeer [START_REF] Lacarrière | Les ressources cynégétiques au Gravettien en France : acquisition et modalités d'exploitation des animaux durant la phase d'instabilité climatique précédant le dernier maximum glaciaire[END_REF]. Higher mobility is supported by technological data. For example, the Grotte du Renne site is located some distance from high quality lithic raw material sources (35 to 120 km according to [START_REF] Klaric | Des armatures variées et des modes de productions variables. Réflexions à partir de quelques exemples issus du Gravettien d'Europe occidentale (France, Portugal, Allemagne)[END_REF], and its Middle Gravettian assemblage shows a high degree of curation, in contrast to other sites that are situated at or near raw material sources, such as the site of La Picardie (although a small percentage of artifacts at La Picardie are made from raw materials coming from sources located in the Charente region, some 200 km away; [START_REF] Delvigne | Taphonomic methods and a database to establish the origin of sedimentary silicified rocks from the Middle-recent Gravettian open-air site of La Picardie (Indre-et-Loire, France)[END_REF]. With respect to curation, Raysse burins (i.e. bladelet cores) from the Grotte du Renne often have double bladelet production platforms, are smaller than those recovered from La Picardie, and the blanks selected to make La Picardie bladelets are generally smaller and are not always typical: many bladelets are more twisted and do not always have a pan-revers and/or a pointed distal end [START_REF] Klaric | Des armatures aux burins : des critères de distinction techniques et culturels à partir des productions lamellaires de quelques sites du Gravettien moyen et récent (France)[END_REF][START_REF] Klaric | La réussite d'une production repose sur l'attention prêtée aux détails »: l'exemple des débitages lamellaires par méthode du Raysse (Gravettien moyen, France)[END_REF][START_REF] Klaric | Des armatures variées et des modes de productions variables. Réflexions à partir de quelques exemples issus du Gravettien d'Europe occidentale (France, Portugal, Allemagne)[END_REF]. In this scenario, the Raysse method could reflect a technological specialization directed at producing armatures for hunting reindeer. It does not mean that reindeer was the only available species in the environment; in fact, other species are always present to a lesser extent in faunal assemblages [START_REF] Lacarrière | Les ressources cynégétiques au Gravettien en France : acquisition et modalités d'exploitation des animaux durant la phase d'instabilité climatique précédant le dernier maximum glaciaire[END_REF]. This could therefore be the result of a cultural choice of northern populations focusing on reindeer (Klaric et al., in press)-a choice that would require higher mobility. Nevertheless, one must be careful to not generalize this pattern, since it relies on only a handful of studies, and numerous sites have assemblages that contain both by-products of the Raysse method and Gravette points, two conceptually different chaînes opératoires (i.e. reduction sequences), and thus different kinds of composite hunting weapons. However, we must bear in mind that occurrences of Picardie bladelets and Gravette points together are observed almost exclusively within cave or rock shelter deposits, where archaeological levels represent palimpsests of multiple occupations that often were subjected to complex post-depositional processes that can homogenize initially distinct occupations. The co-occurrence of the two armature types is also observed at two openair sites: the site of Solvieux in Dordogne [START_REF] Sackett | The Archaeology of Solvieux. An Upper Paleolithic Open Air Site in France[END_REF], where the stratigraphic setting is extremely complex, and Sackett's analysis has raised doubts concerning the integrity of its archaeological assemblages; and the site of Les Jambes in Dordogne [START_REF] Célérier | Le gisement périgordien supérieur des "Jambes". Commune de Périgueux (Dordogne)[END_REF], where slope depositional processes influenced the site's formation (Klaric, 2003, p. 222), thus raising doubts as to whether the distinct archaeological levels defined by Célérier are valid. Whether these two types of armatures-la Picardie bladelets and Gravette/microgravette points-were associated with the same hunting tool-kit or whether their association in the same archaeological level is the result of post-depositional processes or palimpsest deposits, is a subject that requires further study.

At present, the site of Callan represents the only known location of specialized occupations or activities north of the Garonne River [START_REF] Morala | La spécialisation des activités : concept de l'archéologue et réalité archéologique ; les données du site gravettien moyen du Callan (Lot-et-Garonne)[END_REF]. Its lithic assemblage is dominated by Noailles burins and no armatures have been recovered. This general absence of specialized sites suggests that groups in these higher latitude regions had a higher level of residential mobility than those in the Pyrenees. Such a pattern of highly mobile groups using highly standardized and curated toolkits to exploit large territories via a residential system of mobility is in sharp contradiction with the pattern observed during the same period in the Pyrenees. This pattern, though, may be influenced by the lack of chronological resolution for this time-period, which is the result of reduced stratigraphic resolution due to imprecise excavation methods, to post-depositional mixing of levels, palimpsest deposits and the standard errors associated with radiocarbon ages for this period. Such factors make determinations of discrete activity episodes difficult, if not impossible, and the potential homogenization of archaeological levels renders making inferences of how human activities were organized across the landscape difficult.

With respect to the geographic expressions of the estimated niches and the technological differentiation observed between the two regions, what factors potentially influenced these patterns? We propose that the cold desert of the Landes region [START_REF] Bertran | The Landes de Gascogne (southwest France): periglacial desert and cultural frontier during the Palaeolithic[END_REF] and the Garonne River Valley corridor (Bruxelles & Jarry, 2011, 2012) served as an ecological barrier that played a role in the territories exploited by Middle Gravettian hunter-gatherer populations.

The presence of this barrier would have been a factor in limiting the diffusion of the Raysse method to the Pyrenees area. This idea is supported by the fact that this region is associated with low suitability measures (Figure 5), and these suitability scores are even likely to be overestimated since the climatic variables used for this study insufficiently capture the particular conditions of a cold desert whose existence was the result of specific geographic and geomorphic factors [START_REF] Bertran | The Landes de Gascogne (southwest France): periglacial desert and cultural frontier during the Palaeolithic[END_REF]. The presence of this ecological barrier likely influenced the territories exploited by different Middle Gravettian hunter-gatherer populations and thus in term served to create a cultural barrier between the Pyrenees and regions to the north. This hypothesis is supported by the fact that the Pyrenees Noaillian's existing niche is more geographically extensive than the distribution of sites used to reconstruct it, whereas the northern Middle Gravettian niche more closely corresponds to its occurrence data. Thus, the presence of populations in these northern habitats that were characterized by different technological systems and mobility strategies, from which one could infer other cultural differences, could have prevented the Pyrenees populations from occupying their entire existing fundamental niche.

Another observation concerns the northern model's predictions for regions beyond the borders of present-day France-regions in which Noailles burins are present in archaeological assemblages [START_REF] Touzé | De la signification du Noaillien et du Rayssien[END_REF]. There exists a small area of low suitability along the western Italian coast for the northern Middle Gravettian prediction, but the region between this area and the main suitable area in France is predicted as unsuitable. As for the niche associated with the Pyrenees Noaillian, regions east of the French Massif Central are predicted as unsuitable. One possible interpretation is that the Rhône River Valley functioned as a barrier during GS.5. This interpretation, however, is contradicted by the presence of Noailles burins in the lower Rhône River Valley and along the Italian Mediterranean coast [START_REF] Di Cesnola | Il Paleolitico Superiore in Italia[END_REF][START_REF] Onoratini | Le Noaillien dans le complexe Gravettien du sud-est de la France[END_REF][START_REF] Touzé | De la signification du Noaillien et du Rayssien[END_REF]. Moreover, these areas are characterized by a high degree of variability depending on model parametrization, thus indicating that their corresponding suitability estimates are less reliable (Figure 5d). Additional niche predictions, comparisons, and tests that take into account Italian sites, in conjunction with detailed examinations of their lithic industries and comparisons to assemblages to the west, would be necessary to further evaluate this issue.

To the west, the Cantabrian region is characterized by high suitability scores for the Pyrenees Noaillian niche, whereas it is not suitable in the northern Middle Gravettian niche prediction, except for a small portion along the Western Pyrenees. This pattern supports the idea that the Cantabrian region was part of the Pyrenees Noaillian territory-a pattern supported by the presence of Noailles burins in this region [START_REF] Foucher | Le Gravettien des Pyrénées[END_REF]Simonet, 2009a[START_REF] Simonet | Gravettians at Brassempouy (Landes, France), 30,000 BP: a semisedentary territorial organization[END_REF][START_REF] De La Peña | Sobre la unidad tecnologica del Gravetiense en la peninsula Ibérica : implicaciones para el conocimiento del Paleolitico superior inicial[END_REF]. This pattern should be further evaluated with detailed studies of the archaeological assemblages and new niche predictions that include the presence of these sites.

It is also paramount to couple such analyses with critical evaluations of existing chronological data (cf. [START_REF] Banks | An application of hierarchical Bayesian modeling to better constrain the chronologies of Upper Paleolithic archaeological cultures in France between ca. 32,000-21,000 calibrated years before present[END_REF], as well as with efforts to obtain new 14 C ages from reliable archaeological contexts.

Conclusions

Comparisons of the reconstructed niches for the two Middle Gravettian typotechnological faciès, the Noaillian and the Rayssian, in both geographic and environmental dimensions, indicate that their respective niches were significantly different, despite a large degree of overlap in environmental space, due to the fact that the northern Middle Gravettian niche was significantly broader than that of the Pyrenees Noaillian. We interpret this pattern as indicating that the appearance of the Raysse method is related to the exploitation of a significantly broader ecological niche. As opposed to what is observed in areas south of the Garonne River, the Raysse method appears to be associated with particular mobility and settlement strategies contained within a larger exploited territory or territories. Furthermore, this observed pattern suggests that La Picardie bladelets (products of the Raysse method) represented a technological specialization directly associated with a hunting strategy focused on reindeer. Picardie bladelets may have been considered-at least by some hunter-gatherer populations-to be more appropriate within this context than backed points and abrupt backed bladelet armatures (such as Gravette and microgravette points), although this hypothesis warrants further testing in the archaeological record. Furthermore, the Raysse method would have been advantageous in such contexts because it would have been more easily maintainable and adapted to hunting activities organized within territories such that access to raw material resources was less predictable or available. Conversely, we interpret armature diversity of the Pyrenees Noaillian as reflecting an adaptation to the organization of subsistence activities within smaller territories and the use of specialized weapon systems adapted to a variety of prey species and/or situations (e.g. topography). Furthermore, the need for a highly maintainable hunting toolkit was probably not as paramount, since access to raw material resources would have been more predictable or available.

These niche results further support the hypothesis that the Landes cold desert and Garonne River Valley corridor served to limit the homogenization of technological traditions between the Pyrenees and regions to the north. The nature of this barrier (i.e. environmental and/or cultural) warrants further evaluation incorporating other potentially relevant variables (distribution of cold deserts etc.) in future ecological niche modeling analyses that target the concerned archaeological populations. Furthermore, continued investigations centered on identifying Middle Gravettian sites and the typo-technological attributes of their archeological assemblages are needed. In turn, the niche modeling results presented here will provide important context and details for research addressing issues of chronology, settlement and subsistence strategies, lithic raw material exploitation, lithic and bone technologies, and site function pertaining to the Middle Gravettian archaeological record.

Supplementary material

Codes used in R to perform the steps described in sections 2.3.

Figure 1 .

 1 Figure 1. Diagnostic Middle Gravettian artifact types. a. Noailles burin from Fourneau du Diable,

  . Research focused on material culture variability observed in the archaeological record is often polarized between two sets of explanations, cultural vs. functional, mirroring the well-known Bordes-Binford debate concerning Mousterian lithic industries. An advantage of ENM is that it allows one to approach evaluations of such variability from a different angle by taking into account the ecological niches exploited by archaeological hunter-gatherer populations. For example, comparisons of the ecological niches associated with two archaeological cultures or lithic industries allow one to evaluate to what extent cultural (i.e. technological) differences have an ecological basis. In such scenario, one would expect their ecological niches to differ from one another significantly due to the fact that the different typo-techno complexes represent adaptations to distinct ecological niches more than purely social factors. If their niches are highly similar, one could interpret technological variability to be more the result of internal cultural dynamics that led to the development of two cultural trajectories. As stated earlier, multiple hypotheses have been proposed to explain the typo-technological variability observed within the French Middle Gravettian and no consensus has been reached. The objective of this study is to provide new data on the ecological niches of these hunter-gatherer populations in order to evaluate to what extent ecological factors may have played a role in the observed material culture variability.

Figure 2 .

 2 Figure 2. Sites where Noailles burins and/or Raysse burins have been found (after Touzé, 2013; Klaric,

Figure 3 .

 3 Figure 3. BAM diagram representing the factors that constrain the geographic distribution of a species

Figure 4 .

 4 Figure 4. Noaillian and Rayssian site locations used for calibration and the study's defined accessible

  2) and GreenlandStadial 5.2 (GS 5.2) and ends between the latter part of GS 5.1 and GI 4. It was thus present during GS 5.2 and 5.1, during which occurred Heinrich Event 3 (HE3), as well as GI 5.1. Considering the lack of chronological resolution facing this portion of the Upper Paleolithic, two important assumptions were made for the choice of the best possible environmental data. First, since most Middle Gravettian occupations

Figure 5 .

 5 Figure 5. Geographic projections of Maxent-produced median niche estimations. a. Northern Middle

Figure 6 .

 6 Figure 6. Background similarity and identity tests results for comparisons between the northern Middle

Figure 7 .

 7 Figure 7. NicheA Minimum Volume Ellipsoids (MVE) for the northern Middle Gravettian (blue) and

Table

Table 1

 1 -continued

	N° Site	Lat. (N)	Long. (E)	Noailles burins	Raysse method	Data set	References
	Grotte du Trilobite	3,76 47,60 absence	presence	Northern Middle Gravettian	Klaric, 2003; David, 1985
	Hautmougey	6,26 48,00 presence	absence	Northern Middle Gravettian	Hans, 1997
	Abri André Ragout	0,42 45,68 presence	insufficient	Northern Middle Gravettian	Tixier, 1958; David, 1985
	Abri du Chasseur 0,42 45,68 presence	absence	Northern Middle Gravettian	Tixier, 1958; David, 1985
	Les Vachons	0,12 45,51 presence	suspected	Northern Middle Gravettian	David, 1985; Fontaine, 2006
	Le Petit-Puyrousseau	0,72 45,19 presence	insufficient	Northern Middle Gravettian	de Sonneville-Bordes, 1960; Daniel, 1967; David, 1985
							de Sonneville-Bordes,
	Abri Durand-Ruel 0,65 45,37 presence	suspected	Northern Middle Gravettian	1960; Daniel & Schmider, 1972; David,
							1985
	Gisement de la Chèvre	0,59 45,32 presence	insufficient	Northern Middle Gravettian	David, 1985; Arambourou & Jude, 1964
	Combe Saunière	0,87 45,24 presence	presence	Northern Middle Gravettian	Klaric, 2017; Klaric, pers. obs.
	Le Fourneau du Diable	0,59 45,32 presence	presence	Northern Middle Gravettian	David, 1985; Klaric, 2003, 2017; Vignoles et al., 2019
	Les Jambes	0,72 45,19 unlikely	presence	Northern Middle Gravettian	Célérier, 1967; Vignoles, pers.obs.
	Solvieux	0,39 45,06 presence	presence	Northern Middle Gravettian	David, 1985; Sackett, 1999; Klaric, 2003
	Abri Sous-le-Roc 1,09 45,01 insufficient	absence	rejected	de Sonneville-Bordes, 1960; David, 1985
	Abri de Fongal	1,08 44,99 insufficient	insufficient rejected	de Sonneville-Bordes, 1960, p.97; David, 1985
	Abri des Merveilles	1,11 45,00 suspected	absence	rejected	Delage, 1936; de Sonneville-Bordes, 1960; David, 1985
							de Sonneville-Bordes,
	La Rochette	1,09 45,01 presence	suspected	Northern Middle Gravettian	1960; Schmider, 1969; David, 1985; Klaric,
							2003, p.220
	Abri Labattut	1,11 45,00 presence	insufficient	Northern Middle Gravettian	de Sonneville-Bordes, 1960; David, 1985
	Masnaigre	1,14 44,94 presence	suspected	Northern Middle Gravettian	David, 1985
	Abri Pagès	1,04 44,97 presence	absence	Northern Middle Gravettian	de Sonneville-Bordes, 1960; David, 1985
	Abri du Poisson	1,01 44,94 presence	absence	Northern Middle Gravettian	de Sonneville-Bordes, 1960; David, 1985
	Grotte d'Oreille d'Enfer	1,01 44,94 presence	absence	Northern Middle Gravettian	de Sonneville-Bordes, 1960; David, 1985; Pradel, 1959

Table 1

 1 -continued

	N° Site	Lat. (N)	Long. (E)	Noailles burins	Raysse method	Data set	References
	Abri Lespaux	-0,29 44,82 presence	suspected	Northern Middle Gravettian	David, 1985; Krtoliza & Lenoir, 1998
	Le Caillou	0,45 44,78 presence	absence	Northern Middle Gravettian	Boyer et al., 1984
	Roc de Combe-Capelle	0,82 44,77 insufficient	absence	rejected	de Sonneville-Bordes, 1960; David, 1985
	Grotte du Roc de Vézac	2,52 44,89 insufficient	absence	rejected	Rigaud, 1982, p.262; Aujoulat in Leroi-Gourhan, 1984
	Abri des Peyrugues	1,67 44,54 absence	insufficient rejected	Guillermin, 2011
	Abri de la Bergerie	1,58 44,48 presence	absence	Northern Middle Gravettian	Clottes et al., 1990
	Les Battuts	1,73 44,08 presence	suspected	Northern Middle Gravettian	Alaux, 1967; Alaux 1971; David, 1985
	Grotte de Rouzet	1,69 44,00 presence	absence	Northern Middle Gravettian	Foucher et al., 2008
	Abri du Couvert	1,02 44,49 presence	absence	Northern Middle Gravettian	Morala, 1984
	Abri Peyrony	0,89 44,56 presence	absence	Northern Middle Gravettian	Le Tensorer, 1981; David, 1985
	Guiraudel	0,95 44,54 presence	absence	Northern Middle Gravettian	Morala, 1984
	Las Pélénos	0,93 44,50 presence	absence	Northern Middle Gravettian	Morala, 1984
	Le Callan	0,97 44,60 presence	absence	Northern Middle Gravettian	Morala, 2011
	Le Roc de Cavart 1,07 44,54 presence	absence	Northern Middle Gravettian	Le Tensorer, 1981; David, 1985
	Station du Fresquet	0,94 44,47 presence	absence	Northern Middle Gravettian	Morala, 1984
	Gisement du château	1,01 44,59 suspected	absence	rejected	Le Tensorer, 1974, p.467
	Peutille	0,97 44,58 suspected	absence	rejected	Morala, 1984
	Termo-Pialat	0,82 44,77 suspected	absence	rejected	de Sonneville-Bordes, 1960; David, 1985
	Métayer	0,89 44,56 presence	insufficient	Northern Middle Gravettian	Le Tensorer, 1981; David, 1985
	Plateau Baillard	0,89 44,56 presence	absence	Northern Middle Gravettian	Le Tensorer, 1981; David, 1985
	Roquecave	0,89 44,56 presence	absence	Northern Middle Gravettian	Le Tensorer, 1974; Le Tensorer, 1981
							de Sonneville-Bordes,
	Le Roc de Gavaudun	0,89 44,56 presence	suspected	Northern Middle Gravettian	1960; Monméjean et al., 1964; Le Tensorer, 1981;
							David, 1985
	Hin-de-Diou	-0,33 43,86 presence	absence	Pyrenees Noaillian Briand et al., 2010
	Brassempouy	-0,69 43,63 presence	absence	Pyrenees Noaillian	Klaric, 2003; Foucher et al., 2008; Simonet, 2009a

Table 1

 1 -continued

	N° Site	Lat. (N)	Long. (E)	Noailles burins	Raysse method	Data set	References
								David, 1985; Foucher et
	80 Isturitz	-1,20 43,35 presence	insufficient Pyrenees Noaillian	al., 2008; Simonet, 2009a; Lacarrière et al.,
								2011
	81 Lézia	-1,58 43,31 presence	absence	Pyrenees Noaillian	David, 1985; Foucher et al., 2008; Simonet, 2009a
	82 Gatzarria	-0,92 43,14 presence	absence	Pyrenees Noaillian	David, 1985; Foucher et al., 2008; Simonet, 2009a
	83	Grotte des Rideaux	0,67 43,23 presence	absence	Pyrenees Noaillian	David, 1985; Foucher et al., 2008; Simonet, 2009a
	84 Gargas	0,52 43,07 presence	absence	Pyrenees Noaillian	David, 1985; Foucher et al., 2008, 2012
	85 Bois de Touaa	0,83 43,07 presence	absence	Pyrenees Noaillian	Foucher et al., 2008; Clottes, 1985, p. 346
	86 Tuto de Camalhot 1,13 43,01 presence	absence	Pyrenees Noaillian	David, 1985; Foucher et al., 2008; Simonet, 2009a
	87 Grotte d'Enlène	1,20 43,02 presence	absence	Pyrenees Noaillian	Foucher et al., 2008; Simonet, 2009a
	88 Tarté	0,99 43,12 presence	absence	Pyrenees Noaillian	David, 1985; Foucher et al., 2008; Simonet, 2009a
	89 La Carane-3	1,61 42,96 presence	insufficient Pyrenees Noaillian	David, 1985; Foucher et al., 2008; Simonet, 2009a

Table 2 .

 2 Models calibration results. Only one set of parameters was retained for the northern Middle

	Parameters			Evaluation results
					Omission
	Regularization multiplier	Features	Environmental variables	Partial ROC	rates below	AICc ΔAICc	Number of parameters
					5%
	Northern Middle Gravettian
	0.3	LQP	All	0	0 311.258	0
	Pyrenees Noaillian
	0.9	QP	ctemp, mprec	0	0 170.583	0
	1	QP	ctemp, mprec	0	0 170.680 0.098
	2	Q	ctemp, mprec	0	0 170.680 0.098
	3	Q	ctemp, mprec	0	0 171.206 0.623
	3	LQ	ctemp, mprec	0	0 171.206 0.623
	2	QP	ctemp, mprec	0	0 171.758 1.175
	2	LQP	ctemp, mprec	0	0 171.758 1.175
	4	Q	ctemp, mprec	0	0 171.758 1.175
	4	LQ	ctemp, mprec	0	0 171.758 1.175
	0.1	Q	ctemp, wtemp	0	0 172.045 1.463
	0.2	Q	ctemp, wtemp	0	0 172.056 1.473
	0.3	Q	ctemp, wtemp	0	0 172.072 1.489
	0.2	QP	ctemp, wtemp	0	0 172.093 1.510
	0.4	Q	ctemp, wtemp	0	0 172.093 1.510
	0.4	Q	All	0	0 172.093 1.510
	0.5	Q	ctemp, wtemp	0	0 172.119 1.536
	0.5	Q	All	0	0 172.119 1.536
	0.3	QP	ctemp, wtemp	0	0 172.148 1.566
	0.6	Q	ctemp, wtemp	0	0 172.148 1.566
	0.6	Q	All	0	0 172.148 1.566
	0.5	LQ	ctemp, mprec	0	0 172.153 1.570
	0.7	Q	ctemp, wtemp	0	0 172.183 1.600
	0.7	Q	All	0	0 172.183 1.600
	0.3	LQP	ctemp, mprec	0	0 172.197 1.614
	0.6	LQ	ctemp, mprec	0	0 172.197 1.614
	0.4	QP	ctemp, wtemp	0	0 172.220 1.638
	0.8	Q	All	0	0 172.220 1.638
	0.7	LQ	ctemp, mprec	0	0 172.247 1.664
	0.9	Q	ctemp, wtemp	0	0 172.262 1.679
	0.9	Q	All	0	0 172.262 1.679

Table 2 . continued

 2

					Omission
	Regularization multiplier	Features	Environmental variables	Partial ROC	rates below	AICc ΔAICc	Number of parameters
					5%
	0.4	LQP	ctemp, mprec	0	0 172.303 1.721	2
	0.8	LQ	ctemp, mprec	0	0 172.303 1.721	2
	0.5	QP	ctemp, wtemp	0	0 172.306 1.724	2
	1	Q	All	0	0 172.306 1.724	2
	1	Q	ctemp, wtemp	0	0 172.306 1.724	2
	5	Q	ctemp, mprec	0	0 172.311 1.729	1
	5	LQ	ctemp, mprec	0	0 172.311 1.729	1
	0.9	LQ	ctemp, mprec	0	0 172.366 1.783	2
	0.6	QP	ctemp, wtemp	0	0 172.404 1.822	2
	0.6	LQP	ctemp, wtemp	0	0 172.404 1.822	2
	0.5	LQP	ctemp, mprec	0	0 172.433 1.851	2
	1	LQ	ctemp, mprec	0	0 172.433 1.851	2
	0.7	QP	ctemp, wtemp	0	0 172.513 1.930	2
	0.7	LQP	ctemp, wtemp	0	0 172.513 1.930	2
	Consensus niche estimations were thresholded by reclassifying as non-suitable all grid

  Attached to the article is an additional appendix containing a table of criteria used to identify reliable identifications of the Rayssian and the Noaillian in the literature.

				2 and 2.3.3 and models
	calibration	results	are	available	online	at
	https://osf.io/35pb4/?view_only=4f84e08e6ba84754b2090e349bc2ebf4.

Gravettian model, whereas 45 sets of parameters were relevant to the Pyrenees Noaillian model.

indicated in bold. L: linear; Q: quadratic; P: product; ctemp: temperature of the coldest month; wtemp:

temperature of the warmest month; mprec: mean annual precipitation.

Acknowledgements

We thank A. Townsend Peterson for hosting a collaborative trip to the University of Kansas' Biodiversity Institute. The climate simulations were run on the Mercure supercomputer maintained by the Commissariat à l'Energie Atomique's Très Grand Centre de Calculs. We thank A. Townsend Peterson, Mathieu Bosq and Pascal Bertran for their input during the writing of the article. Finally, we thank Andreas Maier and João Marreiros for their critical reviews as part of the Peer Community In open-access reviewing process (https://doi.org/10.24072/pci.archaeo.100003), as well as the two anonymous reviewers for their critics and suggestions that served to improve the paper.

Funding

This research was financed by the LabEx project IMPACT (W. Banks, dir.), and the Nouvelle-Aquitaine region project "GravettoNiches" (W. Banks, dir.). The collaborative trip to the University of Kansas' Biodiversity Institute was co-funded by the University of Bordeaux's "Sciences et Environnements" Doctoral School.