Marine Jeanjean

Cyprien Mureau

Vianney Forest

Allowen Evin

Morphometric evolution of the domestic triad, in western Gallia Narbonensis (southern France, Languedoc), between the 2nd c.BC and the 4th c.AD : Preliminary and critical use of log size index for diachronic analysis

Keywords: Archaeozoology, Antiquity, Biometry, LSI, Animal husbandry

Morphometric evolution of the domestic triad, in

western Gallia Narbonensis (southern France, Languedoc), between the 2nd c.BC and the 4th c.

INTRODUCTION

In domestic mammals, changes in bone measurements, and more generally in body sizes, have been used as marker of domestication (e.g. [START_REF] Uerpmann | Probleme der Neolithisierung des Mittelmeerraums[END_REF], environmental changes (e.g. [START_REF] Davis | The effects of temperature change and domestication on the body size of Late Pleistocene to Holocene mammals of Israel[END_REF][START_REF] Gaughan | Response of domestic animals to climate challenges[END_REF][START_REF] Savolainen | Ecological genomics of local adaptation[END_REF][START_REF] Mccain | Body size and activity times mediate mammalian responses to climate change[END_REF][START_REF] Pacifici | Species' traits influenced their response to recent climate change[END_REF][START_REF] Elayadeth-Meethal | Size does matter: parallel evolution of adaptive thermal tolerance and body size facilitates adaptation to climate change in domestic cattle[END_REF] or husbandry changes (e.g. Albarella et al., 2006a;[START_REF] Grau-Sologestoa | Livestock management in Spain from Roman to post-medieval times: a biometrical analysis of cattle, sheep/goat and pig[END_REF][START_REF] Frémondeau | Pigs and cattle in Gaul: the role of gallic societies in the evolution of husbandry practices[END_REF][START_REF] Robin | The diversity evolution of sheep morphology in French zooarchaeological remains from the 9th to the 19th century: analysis of pastoral strategy[END_REF][START_REF] Trentacoste | Pre-Roman improvements to agricultural production: evidence from livestock husbandry in late prehistoric Italy[END_REF][START_REF] Trentacoste | New trajectories or accelerating change? Zooarchaeological evidence for Roman transformation of animal husbandry in Northern Italy[END_REF][START_REF] Nieto-Espinet | Livestock production, politics and trade: a glimpse from Iron age and roman Languedoc[END_REF].

From a broad perspective, early analyses of biometric data of domestic animal bones revealed a general trend of size decrease from the Neolithic to the end of the Iron Age throughout Europe [START_REF] Matolcsi | Historische Erforschung der Körpergr sse des Rindes aufgrund von ungarischen Knochenmaterial[END_REF][START_REF] Bokonyi | History of Domestic Mammals in Central and Eastern Europe. Akadémiai Kiad ó[END_REF][START_REF] Altuna | Historia de la domesticacion del País Vasco[END_REF][START_REF] Méniel | Contribution à l'histoire de l'élevage en Picardie. Du néolithique à la fin de l'âge du Fer[END_REF][START_REF] Vigne | Les mammifères post-glaciaires de Corse. Etude archéozoologique[END_REF][START_REF] Audoin-Rouzeau | La taille du boeuf domestique en Europe de l'Antiquité aux temps Modernes. La taille du boeuf domestique en Europe de l'Antiquité aux temps Modernes[END_REF][START_REF] Riedel | Archaeozoological investigactions in North-eastern Italy: the exploitation of animals since the Neolithic[END_REF][START_REF] Valenzuela-Lamas | Animal husbandry across the western roman Empire: changes and continuities[END_REF], followed by a size increase during the Roman period [START_REF] Boessneck | Osteological differences between sheep (Ovis aries linné) and goat (Capra hircus linné)[END_REF][START_REF] Bokonyi | History of Domestic Mammals in Central and Eastern Europe. Akadémiai Kiad ó[END_REF][START_REF] Ijzereef | Bronze Age Animal Bones from Bovenkarspel. The Excavation at Hate Valkje[END_REF][START_REF] Méniel | Contribution à l'histoire de l'élevage en Picardie. Du néolithique à la fin de l'âge du Fer[END_REF][START_REF] Audoin-Rouzeau | La taille du boeuf domestique en Europe de l'Antiquité aux temps Modernes. La taille du boeuf domestique en Europe de l'Antiquité aux temps Modernes[END_REF][START_REF] Peters | Römische Tierhaltung und Tierzucht. Eine Synthese aus archäozoologischer Untersuchung und schriftlich-bildlicher Überlieferung[END_REF]. More recent analyses revealed differences between cultural regions (e.g. [START_REF] Frémondeau | Pigs and cattle in Gaul: the role of gallic societies in the evolution of husbandry practices[END_REF][START_REF] Duval | Boeufs gaulois et boeufs français : morphologies animales et dynamiques économiques au cours de La Tène et des périodes historiques[END_REF][START_REF] Trentacoste | Pre-Roman improvements to agricultural production: evidence from livestock husbandry in late prehistoric Italy[END_REF] calling for local analysis of animal size evolution through time.

In Gaul, i.e. a region first described by the Romans and covering present territories of France, Luxembourg, Belgium, and parts of Switzerland, Northern Italy, the Netherlands, and Germany, the size increase of domestic species, especially cattle and pigs, observed during the Roman period. This trend was considered as a direct consequence of the Roman conquest of the Galliae Belgica, Lugdunensis and Aquitania in 52 BCE, and then of the remodelling of their agro-pastoral economies during the first decades of the Roman Empire (Lepetz, 1996b;[START_REF] Méniel | Importation de grands animaux romains et amélioration du cheptel à la fin de l'âge du Fer en Gaule Belgique[END_REF][START_REF] Audoin-Rouzeau | Cheptel antique, cheptel médiéval : mutations ou innovations ? Actes des congrès de la Société d'archéologie médiévale[END_REF]. Several criteria have been evoked to explain this increase in bone size: the importation of large animals from Italy [START_REF] Yvinec | Les restes animaux du silo de Champlieu (Oise)[END_REF][START_REF] Krausz | Les ossements animaux du village des Arènes à Levroux (Indre)[END_REF][START_REF] Méniel | Modifications de l'élevage à la fin de l'âge du Fer[END_REF][START_REF] Méniel | Alimentation carnée, offrandes funéraires et sacrifices animaux chez les Gaulois : archéozoologie à la fin de l'âge du Fer en France septentrionale[END_REF][START_REF] Méniel | Mormont II : les restes animaux[END_REF][START_REF] Benecke | Les restes fauniques d'Alésia[END_REF][START_REF] Gaeng | L'espace public de l'oppidum du Titelberg (L)[END_REF], the changes in pastoral practices (e.g. Lepetz, 1996b) or new environmental characteristics [START_REF] Lepetz | L'élevage à la période gallo-romaine et au haut Moyen ˆAge en Normandie. Apport de l'archéozoologie[END_REF][START_REF] Lepetz | Élevage et agriculture dans le Nord de la Gaule durant l'époque galloromaine : une confrontation des données archéologiques et carpologiques[END_REF][START_REF] Mackinnon | Cattle "breed" variation and improvement in roman Italy: connecting the zooarchaeological and ancient textual evidence[END_REF][START_REF] Duval | Did Romanization impact Gallic pig morphology? New insights from molar geometric morphometrics[END_REF].

In southern France, bones of cattle and caprines reached some of their smallest dimensions ever recorded during the second Iron Age i.e., 5th to 2nd c. BC (Forest, 2015). However, cattle with a "very high" wither height (greater than 1.35 m) did not appear synchronously with the Roman conquest of Gallia Narbonensis, in 121 BCE, but well after, during the middle of the 1st c. AD [START_REF] Columeau | Alimentation carnée en Gaule du sud, Alimentation carnée en Gaule du sud[END_REF]Forest and Rodet-Belarbi, 2002). On the other hand, in the northern provinces of the Italian peninsula the appearance of large cattle occurred from the 1st c. BC [START_REF] Mackinnon | Cattle "breed" variation and improvement in roman Italy: connecting the zooarchaeological and ancient textual evidence[END_REF][START_REF] Kron | Animal Husbandry[END_REF], i.e. at the same time as in northern France (Lepetz, 1996a;[START_REF] Cambou | L'élevage et l'alimentation carnée en Bourgogne de la Tène finale au Bas-Empire[END_REF][START_REF] Foucras | Animaux domestiques et faunes sauvages en territoire arverne (Ve s. av. J.-C. -Ier s[END_REF][START_REF] Lepetz | Productions agropas-torales, pratiques culturales et élevage dans le nord de la gaule du deuxième siècle avant J.-C à la fin de la période romaine, Autun, Mergoil[END_REF][START_REF] Duval | Boeufs gaulois et boeufs français : morphologies animales et dynamiques économiques au cours de La Tène et des périodes historiques[END_REF]. This would imply a contemporary appearance of large cattle in several territories before, and therefore probably independently of, the expansion of the Roman Empire. Moreover, this increase in cattle size continues in Italy until Late Antiquity [START_REF] Mackinnon | Production and Consumption of Animals in Roman Italy: Integrating the Zooarchaeological and Textual Evidence[END_REF], as in Narbonese Gaul [START_REF] Columeau | Alimentation carnée en Gaule du sud, Alimentation carnée en Gaule du sud[END_REF]Forest, 2008), Northern Gaul and Germanies (Lepetz, 1996b;[START_REF] Duval | Diversité des cheptels et diversification des morphotypes bovins dans le tiers nord-ouest des Gaules entre la fin de l ' ˆage du Fer et la période romaine[END_REF]Pigiere, 2017) or in England [START_REF] Maltby | Iron Age, Romano-British and Anglo-Saxon animal husbandry a review of the faunal evidence[END_REF][START_REF] Dobney | A Place at the table: the role of vertebrate zooarchaeology within a Roman research agenda[END_REF][START_REF] Albarella | The end of the sheep age: people and animals in the late Iron age[END_REF][START_REF] Rizzetto | Les transformations de l'élevage au début et à la fin de l'époque romaine en Grande Bretagne : questions d'acculturation, d'adaptation et « d'amélioration[END_REF].

The fact that a similar progressive dynamic is observed on a large geographical scale does not exclude a movement of large Roman animals, which appeared as early as the 4th c. BC in southern Italy [START_REF] Baker | Society and Economy in Northern Italy in the Early Medieval Period (C. 6th-11th). A Zooarchaeology Study[END_REF]. However, it tends to favour the hypothesis that local populations evolved more slowly than would have been expected to have resulted from a massive import of large Italian cattle.

The Log Size Index (LSI) approach has helped reinvigorate interest in the size evolution of the domestic animals, and is now a standard in zooarchaeology (e.g. [START_REF] Uerpmann | Animal bone finds from excavation 520 at Qala'at al-Bahrain[END_REF][START_REF] Davis | Measurements of a group of adult female Shetland sheep skeletons from a single flock: a baseline for zooarchaeologists[END_REF][START_REF] Meadow | The use of size index scaling techniques for research on archaeo-zoological collections from the Middle East. Historia animalium ex ossibus. Contributions to palaeo-anatomy, archaeology, egyptology, ethnology and veterinary history[END_REF][START_REF] Baudry | Ressources animales et alimentation carnée à l'ˆAge du Fer: le cas du nord-ouest de la France (Bretagne et Basse-Normandie)[END_REF][START_REF] Duval | Did Romanization impact Gallic pig morphology? New insights from molar geometric morphometrics[END_REF][START_REF] Robin | The diversity evolution of sheep morphology in French zooarchaeological remains from the 9th to the 19th century: analysis of pastoral strategy[END_REF], even if the approach has been criticized (e.g. [START_REF] Wolfhagen | Re-examining the use of the LSI technique in zooarchaeology[END_REF]. LSI techniques have been developed to address sample size issues by artificially increasing the number of measurements that can be analysed together (e.g. [START_REF] Weinstock | Reindeer hunting in the Upper Palaeolithic: sex ratios as a reflection of different procurement strategies[END_REF]Albarella et al., 2006b;[START_REF] Sykes | New evidence for the establishment and management of the European fallow deer (Dama dama dama) in Roman Britain[END_REF][START_REF] Arbuckle | Data sharing reveals complexity in the westward spread of domestic animals across Neolithic Turkey[END_REF][START_REF] Arbuckle | Documenting the initial appearance of domestic cattle in the Eastern Fertile Crescent (northern Iraq and western Iran)[END_REF][START_REF] Grau-Sologestoa | Animal husbandry between the Roman times and the High Middle Ages in central Europe: a biometrical analysis of cattle, sheep and pig[END_REF]Schmolcke and Groβ, 2021). This method, originally described by Simpson [START_REF] Simpson | Large pleistocene felines of north America -explanation of ratio diagrams[END_REF][START_REF] Simpson | Quantitative Zoology[END_REF] and later developed by [START_REF] Meadow | The use of size index scaling techniques for research on archaeo-zoological collections from the Middle East. Historia animalium ex ossibus. Contributions to palaeo-anatomy, archaeology, egyptology, ethnology and veterinary history[END_REF], consists on a normalisation of bone measurements of interest using a reference. This reference could correspond either to the measurements of a single individual (e.g. [START_REF] Zeder | Animal domestication in the zagros: an update and directions for future research[END_REF][START_REF] Duval | Diversité des cheptels et diversification des morphotypes bovins dans le tiers nord-ouest des Gaules entre la fin de l ' ˆage du Fer et la période romaine[END_REF][START_REF] Arbuckle | Data sharing reveals complexity in the westward spread of domestic animals across Neolithic Turkey[END_REF][START_REF] Zeder | Animal domestication in the zagros: an update and directions for future research[END_REF]Lemoine, 2020a, 2020b), or mean measurements of several specimens (e.g. Degerbol and Fredskild, 1970;[START_REF] Payne | Components of variation in measurements of pig bones and teeth, and the use of measurements to distinguish wild from domestic pig remains[END_REF][START_REF] Clutton-Brock | Osteology of soay sheep[END_REF][START_REF] Uerpmann | Animal bone finds from excavation 520 at Qala'at al-Bahrain[END_REF][START_REF] Davis | Measurements of a group of adult female Shetland sheep skeletons from a single flock: a baseline for zooarchaeologists[END_REF][START_REF] Davis | The effect of castration and age on the development of the Shetland sheep skeleton and a metric comparison between bones of males, females and castrates[END_REF][START_REF] Hongo | Faunal remains from Prepottery Neolithic levels at Çayönü, southeastern Turkey: a preliminary report focusing on pigs (Sus sp.)[END_REF][START_REF] Steppan | Ur oder hausrind? Die variabilität der Wildtieranteile in line-abandkermischen tierknochenkomplexen[END_REF][START_REF] Weinstock | Reindeer hunting in the Upper Palaeolithic: sex ratios as a reflection of different procurement strategies[END_REF][START_REF] Johnstone | The Late Iron Age and Romano-British Mammal and Bird Bone Assemblage from Elms Farm[END_REF][START_REF] Albarella | Neolithic pigs from durrington walls, wiltshire, England: a biometrical database[END_REF]Albarella et al., 2006a;2009;[START_REF] Mackinnon | Cattle "breed" variation and improvement in roman Italy: connecting the zooarchaeological and ancient textual evidence[END_REF][START_REF] Sykes | New evidence for the establishment and management of the European fallow deer (Dama dama dama) in Roman Britain[END_REF][START_REF] Telldahl | Osteometric and molecular sexing of cattle metapodia[END_REF][START_REF] Valenzuela | Tracing changes in animal husbandry in Mallorca (Balearic Islands, Western Mediterranean) from the Iron Age to the Roman Period[END_REF][START_REF] Manin | Sexual dimorphism among Mesoamerican turkeys: a key for understanding past husbandry[END_REF][START_REF] Helmer | The fauna of Tell Aswad (Damascus, Syria), early Neolithic levels. Comparison with northern and southern Levant sites[END_REF][START_REF] Robin | The diversity evolution of sheep morphology in French zooarchaeological remains from the 9th to the 19th century: analysis of pastoral strategy[END_REF][START_REF] Nieto-Espinet | Resilience and livestock adaptations to demographic growth and technological change: a diachronic perspective from the Late Bronze Age to Late Antiquity in NE Iberia[END_REF].

The LSI method is based on the assumption of isometric variation between the measurements, i.e. all variables vary in a similar manner [START_REF] Albarella | Size matters": how and why biometry is still important in zooarchaeology[END_REF]Albarella et al., 2006a;[START_REF] Wolfhagen | Re-examining the use of the LSI technique in zooarchaeology[END_REF]Zeder and Lemoine, 2020a). However, it is known that this is not always the case as bone lengths have been shown to be more related to the wither height of the animal, whereas bone breadths and depths correlate more with corpulence [START_REF] Uerpmann | Through a world of sheep[END_REF][START_REF] Guintard | Étude ostéométrique des métapodes de bovins : la race charolaise[END_REF][START_REF] Meadow | The use of size index scaling techniques for research on archaeo-zoological collections from the Middle East. Historia animalium ex ossibus. Contributions to palaeo-anatomy, archaeology, egyptology, ethnology and veterinary history[END_REF][START_REF] O'connor | The Archaeology of Animal Bones[END_REF]. Accordingly, in order to mitigate the effect of potential allometries on LSI values, measurements of length, breadth and sometimes depth dimensions of the bones are sometimes, but not systematically, studied separately (e.g. [START_REF] Duval | Diversité des cheptels et diversification des morphotypes bovins dans le tiers nord-ouest des Gaules entre la fin de l ' ˆage du Fer et la période romaine[END_REF][START_REF] Trentacoste | Pre-Roman improvements to agricultural production: evidence from livestock husbandry in late prehistoric Italy[END_REF][START_REF] Trentacoste | Fodder for change: animals, urbanisation, and socio-economic transformation in protohistoric Italy[END_REF][START_REF] Nieto-Espinet | Livestock production, politics and trade: a glimpse from Iron age and roman Languedoc[END_REF], 2021;[START_REF] Ameen | In search of the 'great horse': a zooarchaeological assessment of horses from England (AD 300-1650[END_REF][START_REF] Salvagno | A method to assess wear rate in pig teeth from archaeological sites[END_REF][START_REF] Wright | Investigating cattle husbandry in the Swiss Late Neolithic using different scales of temporal precision: potential early evidence for deliberate livestock "improvement[END_REF].

In Gaul, the LSI-length of cattle and pigs starts to increase at the end of the 3rd c. BC and this size increase intensifies during the 1st c. BC for cattle [START_REF] Frémondeau | Pigs and cattle in Gaul: the role of gallic societies in the evolution of husbandry practices[END_REF][START_REF] Duval | Boeufs gaulois et boeufs français : morphologies animales et dynamiques économiques au cours de La Tène et des périodes historiques[END_REF]Duval et al., 2018). A similar change has been noted in northern Italy for cattle [START_REF] Grossi Mazzorin | Changes in lifestyle in ancient rome (Italy) across the Iron age/roman transition[END_REF][START_REF] Valenzuela-Lamas | Animal husbandry across the western roman Empire: changes and continuities[END_REF][START_REF] Trentacoste | Pre-Roman improvements to agricultural production: evidence from livestock husbandry in late prehistoric Italy[END_REF]. In contrast, for pigs, the LSI-length tends to decrease between the 8th c. BC and the Roman period, when LSI-breadth remains constant throughout the period [START_REF] Trentacoste | New trajectories or accelerating change? Zooarchaeological evidence for Roman transformation of animal husbandry in Northern Italy[END_REF]. Finally, although wither height analyses indicated a gain in size for sheep and goats during the Roman period in Gaul (Lepetz, 1996b), this increase appears, at the same time, very limited in Italy and more visible for sheep on the LSI-breadth than on the LSI-length [START_REF] Trentacoste | Pre-Roman improvements to agricultural production: evidence from livestock husbandry in late prehistoric Italy[END_REF][START_REF] Trentacoste | New trajectories or accelerating change? Zooarchaeological evidence for Roman transformation of animal husbandry in Northern Italy[END_REF]. All these results question the hypothesis of a sudden increase in size of domestic animals in Gaul through the importation of Italian herds, but also that of a transmission of Roman know-how during the Roman conquests of the Gallia Narbonensis in 121 BCE and in the northern Gaul in 52 BCE.

While time is often divided into chrono-cultural phases (e.g. [START_REF] Albarella | The development of animal husbandry from the Late Iron Age to the end of the Roman period: a case study from South-East Britain[END_REF]Colominas and Sana, 2009;[START_REF] Grau-Sologestoa | Livestock management in Spain from Roman to post-medieval times: a biometrical analysis of cattle, sheep/goat and pig[END_REF][START_REF] Colominas | Roman conquest and changes in animal husbandry in the north-east of the Iberian Peninsula: searching for patterns, and singularities[END_REF][START_REF] Groot | Evolution de l'élevage et de l'approvisionnement en Germanie inférieure à l'époque romaine[END_REF]Pigiere, 2017;[START_REF] Rizzetto | Les transformations de l'élevage au début et à la fin de l'époque romaine en Grande Bretagne : questions d'acculturation, d'adaptation et « d'amélioration[END_REF][START_REF] Valenzuela-Lamas | Animal husbandry across the western roman Empire: changes and continuities[END_REF][START_REF] Duval | Boeufs gaulois et boeufs français : morphologies animales et dynamiques économiques au cours de La Tène et des périodes historiques[END_REF][START_REF] Robin | The diversity evolution of sheep morphology in French zooarchaeological remains from the 9th to the 19th century: analysis of pastoral strategy[END_REF], some studies have evidenced the possibility of using time as a continuous variable. In such cases, the mean time of occupation of chrono-cultural phases or sites are often used, even if the archaeological records often allow a more detailed resolution, at the scale of the stratigraphic unit [START_REF] Arbuckle | Data sharing reveals complexity in the westward spread of domestic animals across Neolithic Turkey[END_REF][START_REF] Arbuckle | Documenting the initial appearance of domestic cattle in the Eastern Fertile Crescent (northern Iraq and western Iran)[END_REF][START_REF] Frémondeau | Pigs and cattle in Gaul: the role of gallic societies in the evolution of husbandry practices[END_REF]Duval et al., 2018).

In our study area, a particularly large amount of archaeozoological studies has been carried out by the many specialists working in preventive archaeology and published through excavation reports which, as grey literature, are yet not widely integrated into academic research. This long-term work has resulted in a particularly large body of raw data and a detailed understanding of the archaeological occupations at the site level.

In this context, this study aims, through a critical use of the LSI for diachronic analysis, using time as a continuous variable and a larger dataset than those studied before, to provide a more detailed synthesis on metric change in the domestic triad, i.e. caprines (goat & sheep), cattle and suids, in western Narbonese Gaul between the 2nd century BC and the 4th century AD. For this purpose, we used LSI-values analysed first for each variable independently, then pooled by length, breadth and depth dimensions before studying the overall diachronic trends of the four species.

MATERIALS

This study focuses on 64 archaeological assemblages located in the south of France, in the Gallia Narbonensis region corresponding to the modern Languedoc (Fig. 1, SI table 1). Our study focuses on the time period ranging from 200 BCE to 400 AD and includes assemblages for which the mean of the earliest (terminus post quem, TPQ) and latest (terminus ante quem, TAQ) dates fall within the defined period. The chronological data were recorded according to existing archaeological reports (SI table 1). All the faunal remains analysed here were studied by a single specialist, Vianney Forest, who is also the only person to have carried out the biometric measurements (SI table 1). This is to avoid any interoperator bias, also called ʻpersonal equation' [START_REF] Sumner | Linear and colorimetric measurements of small mammals[END_REF][START_REF] Jewell | Body measurements of small mammals: sources of error and anatomical changes[END_REF][START_REF] Yablokov | Variability of mammals[END_REF]. All data were collected in the context of preventive archaeology over the last 30 years, first by AFAN -'Association pour les Fouilles Archéologiques Nationales' and then INRAP -'French Institute for Preventive Archaeological Research'.

All raw measurements are available in the excavation reports of the corresponding archaeological sites (SI table 1). Wild boars were not distinguished from domestic pigs, and aurochs seem to have disappeared from the Languedoc between the Final Bronze Age and the beginning of the Iron Age [START_REF] Forest | Les lièvres, les tortues et l'aurochs : une histoire archéozoologique en Languedoc-Roussillon[END_REF]. The distinction of sheep and goat bones was done using published macroscopic criteria [START_REF] Cornevin | Caractères ostéologiques différentiels de la chèvre et du mouton[END_REF][START_REF] Boessneck | Osteologische unterscheidungsmerkmale zwischen schaf (Ovis aries Linné) und ziege (Capra hircus Linné)[END_REF][START_REF] Prummel | A guide for the distinction of species, sex and body side in bones of sheep and goat[END_REF][START_REF] Helmer | Atlas du Squelette Appendiculaire Des Principaux Genres Holocènes De Petits Ruminants Du Nord De La Méditerranée Et Du Proche-Orient[END_REF]) and personal expertise. The biometric measurements were acquired following the von den Driesch standards (von den [START_REF] Den Driesch | A Guide to the Measurement of Animal Bones from Archaelogical Sites[END_REF] with new measurements (SI Fig. 1).

The analyses focus on bones of the appendicular skeleton of adult sheep, goats, suids and cattle. Only measurements with a minimum of two values were retained for the analyses. Infant and juvenile specimens were excluded. In contrast, bones which were still unfused, or incomplete for which it was not possible to establish the fusing stage, but showing apparent definitive ossification, were retained. Due to the lack of knowledge on laterality and rank, phalanges and unidentified suids metapodials were excluded from the corpus. The compilation of all biometric data includes a total of 5533 measurements (SI table 1; SI table 2).

METHODS

The log size index (LSI) is obtained by calculating the difference between the decimal logarithm of each measurement from the archaeological material (x) and the corresponding measurement of a reference (y) [START_REF] Simpson | Large pleistocene felines of north America -explanation of ratio diagrams[END_REF][START_REF] Meadow | The use of size index scaling techniques for research on archaeo-zoological collections from the Middle East. Historia animalium ex ossibus. Contributions to palaeo-anatomy, archaeology, egyptology, ethnology and veterinary history[END_REF]. The formula can be expressed as follows: LSI = Log (x/y) = Log (x) -Log (y). This is actually a scaling technique for the size index [START_REF] Meadow | Early animal domestication in South Asia: a first report of the faunal remains from Mehrgarh, Pakistan[END_REF][START_REF] Meadow | The use of size index scaling techniques for research on archaeo-zoological collections from the Middle East. Historia animalium ex ossibus. Contributions to palaeo-anatomy, archaeology, egyptology, ethnology and veterinary history[END_REF]. As reference population, we used the average of each variable measured in the studied dataset (SI table 3). Thus, larger specimens than average will have positive values, while smaller specimens will have negative values. It should be noted that the size measurement expressed by LSI does not correspond to the body height classically interpreted in archaeozoology, as it is based on measurements taken in many different directions. Each measurement is dated by the mean of the possible time range of occupation, corresponding to the mean of the TPQ and TAQ of its stratigraphic unit. All analyses were performed in R (R Core Team, 2021), and LSI calculations are done with the zoolog package [START_REF] Pozo | Zoolog R package: zooarchaeological analysis with log-ratios[END_REF].

Traditionally, LSI values obtained from various variables are compared using e.g. t-test or Mann-Whitney test to ensure their homogeneity and detect allometries, i.e. when different variables provide different information (e.g. [START_REF] Albarella | Size and shape of the Eurasian wild boar (Sus scrofa), with a view to the reconstruction of its Holocene history[END_REF][START_REF] Duval | Diversité des cheptels et diversification des morphotypes bovins dans le tiers nord-ouest des Gaules entre la fin de l ' ˆage du Fer et la période romaine[END_REF][START_REF] Duval | Boeufs gaulois et boeufs français : morphologies animales et dynamiques économiques au cours de La Tène et des périodes historiques[END_REF][START_REF] Trentacoste | Pre-Roman improvements to agricultural production: evidence from livestock husbandry in late prehistoric Italy[END_REF][START_REF] Trentacoste | New trajectories or accelerating change? Zooarchaeological evidence for Roman transformation of animal husbandry in Northern Italy[END_REF]. When LSI values are studied diachronically, with time being analysed as a continuous variable, the different variables are usually not compared to each other (e.g. [START_REF] Arbuckle | Data sharing reveals complexity in the westward spread of domestic animals across Neolithic Turkey[END_REF][START_REF] Arbuckle | Documenting the initial appearance of domestic cattle in the Eastern Fertile Crescent (northern Iraq and western Iran)[END_REF]Duval et al., 2018). Here, changes in the LSI values through time were assessed by a smoothing method based on a local polynomial regression fitting (function loess of the R package ʻstats' [START_REF] Cleveland | Local regression In[END_REF]). A 90% confidence interval was added to the regression curve. Non-overlapping confidence intervals of two curves indicate significant differences.

Conversely, an increase or decrease in LSI values through time was considered significant only when the confidence intervals did not overlap. The evolution of the LSI values through time was explored between 200 AD and 400 BCE and visualised as a biplot with time represented along the x-axis, and LSI values along the y-axis.

In order to test for allometric differences between bones and between variables of each bone as already detected by previous studies (e.g. Zeder and Lemoine, 2020a), LSI values were first analysed separately for each variable. Then the variables were divided and analysed by dimension separating the length, breadth or depth measurements following [START_REF] Duval | Evolution et diversité de la forme du cochon entre l'âge du Fer et la période moderne en Gaule et en France. Régionalisme, acquisitions zootechniques et implications historiques[END_REF] (SI table 4) and as recommended by different authors [START_REF] Uerpmann | Animal bone finds from excavation 520 at Qala'at al-Bahrain[END_REF][START_REF] Davis | Measurements of a group of adult female Shetland sheep skeletons from a single flock: a baseline for zooarchaeologists[END_REF][START_REF] Meadow | The use of size index scaling techniques for research on archaeo-zoological collections from the Middle East. Historia animalium ex ossibus. Contributions to palaeo-anatomy, archaeology, egyptology, ethnology and veterinary history[END_REF][START_REF] Baudry | Ressources animales et alimentation carnée à l'ˆAge du Fer: le cas du nord-ouest de la France (Bretagne et Basse-Normandie)[END_REF][START_REF] Duval | Evolution et diversité de la forme du cochon entre l'âge du Fer et la période moderne en Gaule et en France. Régionalisme, acquisitions zootechniques et implications historiques[END_REF][START_REF] Robin | The diversity evolution of sheep morphology in French zooarchaeological remains from the 9th to the 19th century: analysis of pastoral strategy[END_REF]. After these preliminary analyses, ensuring the homogeneity of the variables, all LSI values were pooled by taxa and visualised jointly.

In order to apprehend the allometric bias in LSI analysis, and thus to illustrate their potential over interpretation, we explored the variation of LSI values for archaeological specimens from the dataset, represented by multiple bones. Our dataset includes 23 skeletons from 15 sites attributed to single specimens. The range of their LSI values was calculated as the difference between the minimal and maximal of all their LSI values.

RESULTS

A total of 5533 measurements were analysed corresponding to 1950 measurements of cattle, 2197 of suids, 1113 of sheep and 273 of goat.

LSI per bone

Overall, for each taxon and each bone, the LSI values of the various variables tend to overlap (Fig. 2), although some differences exist and not all bones show the same pattern over time. In general, the number of measurements is smaller at the extremes of the chronological period (SI Fig. 2) as evidenced by larger confidence intervals.

For cattle (Fig. 2A), the scapula shows a different pattern compared to the other bones, with a similar bell shape trend characterized by an increase of LSI values up to a point where the measurements decrease. The SLC reaches its maximum around 200 AD, nearly two hundred years later than the variables BG and GLP.

The metacarpal, the talus and the metatarsal have all their variables largely overlapping and show a main trend of increase in LSI values until a plateau. The plateau is reached at different times depending on the bone. The talus shows a maximum in LSI values around the middle of the 2nd c. AD, as in the case of metatarsal Bd. For the other variables of the metatarsal, the maximum appeared earlier, at the end of the 1st c. AD. The trend of the metacarpal is less clear with a maximum reached at the turn of our era for the GL variable, during the 2nd c. AD for the Bp and the Bd, while the SD shows a constant increase and does not reach a plateau.

For suids, bones show relatively different trends in LSI values through time. On the one hand, variables of the humerus and SLC of the scapula increase until the beginning of the 2nd c. AD, followed by a plateau. On the other hand, variables of the talus only increase during the 1st c. BC and no variation can be observed for the ulna until the 2nd c. AD. The scarcity of measurements makes interpretations of the trends at the end of the period difficult, but only SD of the humerus decreases significatively (Fig. 2B). For sheep, the variables of each bone largely overlap (Fig. 2C). The talus and the tibia seem to show a similar, but insignificant, increase of LSI values though time. The scapula, represented by less measurements, and the metatarsal appear stable over time.

As a whole, this approach shows a relatively homogeneous evolution between variables of a bone for each taxon and, frequently, different patterns between the bones studied. Moreover, the trends of certain variables seem to be influenced by a limited number of measurements, which calls for great caution in the interpretations.

Breath, depth, and length

Variables were then combined according to the dimension they represent: breadth, depth or length.

For cattle, the analysis of the three dimensions revealed different patterns through time. For breadth all variables largely overlap although small but significant differences can be noted. For example, the scapula shows higher values than femur, talus and naviculocuboid during the first century BC. The scapula also shows higher than metacarpus during the first century AD, when the talus shows lower values than humerus, radius, femur and tibia. Finally, talus and metapods show higher values than radius during the third c. AD.

For depth the talus and calcaneus show opposite trends to the ulna. A difference is also observed for the length of the metapodials, reaching their maximum during the 1st c. AD, while the talus reaches it at the beginning of the 2nd c. AD.

Altogether, the three dimensions of cattle show a relatively similar pattern with a maximum around the turn of the 2nd c. AD. From there, and until the end of the 4th c. AD, LSI-breadth stagnates while LSI depth and length decrease (Fig. 3). Depth values appear smaller than breadth and length from the 1st c. BC to the 1st c. AD, and again smaller than breadth during the 4th c. AD.

For the three dimensions of suids, the variables largely overlap and show little variation through time (Fig. 3). LSI-depth increase slightly until the middle of the 2nd c. AD in two steps, with a plateau during the 1st c. AD. LSI-breath and length reach their maximum during the 2nd c. AD. Then, LSI-depth and length seem to stagnate, while LSI-breadth decreases until the end of the 4th c. AD.

For goat, only breadth variables of the radius and metacarpal were represented by enough measurements to be visualised, though, due to their relatively small number, interpretations should be made with caution. When the variables are pooled, the three dimensions largely overlap.

For sheep, curves of the three dimensions largely overlap and show a similar evolution through time with little variation.

Fig. 3. Log Size Index evolution by taxa and dimension between 200 BCE and 400 AD. Dimensions of each variable

were attributed following [START_REF] Duval | Evolution et diversité de la forme du cochon entre l'âge du Fer et la période moderne en Gaule et en France. Régionalisme, acquisitions zootechniques et implications historiques[END_REF] (SI Table 4). Only the bones with at least 30 measurements per dimension are presented by dimension. For goat, only breadth measurements were numerous enough to be represented. For the total representation, all variables with more than two measurements were included. Each point corresponds to a LSI value plot in y against time in x. The sample sizes follow "n = ".

Overall evolution of the species through time

All LSI values were then pooled to compare changes between the four species (Fig. 4). Cattle is the species showing the greatest variation in LSI values through time. Their size is at its lowest at the beginning of the period, then reaches a maximum in the early 2nd c. AD, followed by a decrease until the beginning of the 4th c. AD. Suids size also increases until the turn of the 2nd c. AD, but in two stages, during the 1st c. BC and more briefly in the first half of the 2nd c. AD, separated by a stagnation phase throughout the 1st c. AD. Then, suids size remains stable during the 2nd c. AD before decreasing until the end of the period. Sheep and goat change in a relatively similar manner with some differences. Goat size increases from the beginning of the 1st c. BC (not enough data were available before this date) to the second half of the 1st c. AD, followed by a plateau until at least the end of the 3rd c. AD (the confidence intervals overlap over time), potentially followed by a size decrease, evidenced by only few measurements to reach a size similar to those observed at the beginning of the period. Sheep also show their minimal size at the beginning of the studied period, which increases until the middle of the 1st c. AD up to a plateau with no change in size until the beginning of the 3rd c. AD, before increasing again to reach their largest size at the end of the study period.

Individual variation of LSI values

LSI values were obtained from bone assemblages corresponding to 23 single individuals (Fig. 5). Intraspecimen LSI variation appears important with regards to the variation of species over time (Fig. 5A). The LSI range spread between 0.07 and 0.26 for cattle, 0.11 and 0.31 for suids, and 0.05 and 0.10 for sheep (Fig. 5B).

For cattle and suids, the LSI range per specimen does not vary with the number of measurements available (corr = 0.16756, t = 0.61283, df = 13, p-value = 0.5506 for cattle, corr = 0.46953, t = 0.92112, df = 3, p-value = 0.4249 for suids) or time (mean TPQ/TAQ) (corr = -0.40624, t = -1.603, df = 13, p-value = 0.133 for cattle, corr = -0.54839, t = -1.1359, df = 3, p-value = 0.3385 for suids). Due to small number of bone assemblages for sheep (n = 2), correlation tests were not performed for this species.

DISCUSSION

Overall, the results appeared highly influenced by the number of measurements per variable. In some instances, non-overlapping confidence intervals, that should be interpreted as significant differences between variables, were in fact based on too little data to reach definitive conclusions. Differences between variables or between dimensions, i.e. allometries, exist and should be carefully inspected before making widespread use of Log Size Index approaches when studying a specific species. However, those allometries appeared low compared to the long-term diachronic variation and the inter-species differences.

Choice of dataset and critical use of the LSI for diachronic analysis

By using measurements from a single operator, we avoided potential bias linked to inter-operator measurement error known to be potentially important for biometric data [START_REF] Yezerinac | Measurement error and morphometric studies: statistical power and observer experience[END_REF][START_REF] Evin | Optimizing digitalization effort in morphometrics[END_REF]. Surprisingly, the existence of differences between operators does not seem to be considered in current syntheses based on LSI approaches, and may require further exploration. Besides, while in our study all the bones attributed to adults were measured, even if they were incomplete or unfused, this may vary upon operator. For example, while von den Driesch (1976) reference measurements advocate measurement of only "full grown animals", some authors only measure fully fused elements (e.g. [START_REF] Duval | Boeufs gaulois et boeufs français : morphologies animales et dynamiques économiques au cours de La Tène et des périodes historiques[END_REF], fused elements (e.g. [START_REF] Albarella | Size and shape of the Eurasian wild boar (Sus scrofa), with a view to the reconstruction of its Holocene history[END_REF] or a set of fusing and fused elements (e.g. [START_REF] Albarella | Neolithic pigs from durrington walls, wiltshire, England: a biometrical database[END_REF][START_REF] Albarella | The development of animal husbandry from the Late Iron Age to the end of the Roman period: a case study from South-East Britain[END_REF]. Thus, the inclusion of younger specimens by some operators may result in an increase in the number of small LSI values.

In this study, we demonstrate important variation in LSI values within single skeletons. Including skeletal groups in an analysis has the advantage of providing a large number of measurements, and highlighting potential allometries. On the other hand, it gives more weight to some specimens in the calculations. To avoid this over-representation, some authors select only one measurement per bone [START_REF] Grau-Sologestoa | Animal husbandry between the Roman times and the High Middle Ages in central Europe: a biometrical analysis of cattle, sheep and pig[END_REF], one measurement per bone from any group of articulated remains [START_REF] Trentacoste | Pre-Roman improvements to agricultural production: evidence from livestock husbandry in late prehistoric Italy[END_REF][START_REF] Trentacoste | New trajectories or accelerating change? Zooarchaeological evidence for Roman transformation of animal husbandry in Northern Italy[END_REF][START_REF] Nieto-Espinet | Resilience and livestock adaptations to demographic growth and technological change: a diachronic perspective from the Late Bronze Age to Late Antiquity in NE Iberia[END_REF] or average values per dimension of a bone [START_REF] Duval | Evolution et diversité de la forme du cochon entre l'âge du Fer et la période moderne en Gaule et en France. Régionalisme, acquisitions zootechniques et implications historiques[END_REF]. How the measurement is selected remains unclear and can affect the analyses since, as we have demonstrated, allometry is not absent from LSI analyses. Here we included all available measurements and took advantage of bone assemblages belonging to single specimens to determine the intraspecimen range of LSI variation. This variation is about 0.07-0.16 in most cattle (n = 13), but can exceptionally exceed 0.2 (n = 2). In suids, it always exceeds 0.1 and even reaches 0.3 in an individual from Nimes "Place d'Assas" (60-70 AD).

Two important factors certainly contribute to the overall observed LSI variation and were not assessed in this study: sexual dimorphism and the potential presence of wild and domestic specimens in the dataset.

In this study, as in most cases when working with archaeozoological assemblages, males and females could not be differentiated, though no groups of size were detected in our analyses. Some studies focus only on elements with low sexual dimorphism (e.g. [START_REF] Albarella | Size and shape of the Eurasian wild boar (Sus scrofa), with a view to the reconstruction of its Holocene history[END_REF][START_REF] Grau-Sologestoa | Animal husbandry between the Roman times and the High Middle Ages in central Europe: a biometrical analysis of cattle, sheep and pig[END_REF], but that requires selecting measurements and therefore reducing the dataset. Conversely, variables known to be sexually dimorphic can also be used to better explore the differences between males and females (e.g. [START_REF] Grau-Sologestoa | Animal husbandry between the Roman times and the High Middle Ages in central Europe: a biometrical analysis of cattle, sheep and pig[END_REF] and potentially explore changes in sex ratio potentially linked with past husbandry practices (e.g. use of animals for labour or milk production).

The presence of aurochs (Bos primigenius), ancestor of cattle, was not considered in this study since its last detected occurrence in the region dates from between the Final Bronze Age and the beginning of the Iron Age [START_REF] Forest | Les lièvres, les tortues et l'aurochs : une histoire archéozoologique en Languedoc-Roussillon[END_REF]. Conversely, wild boars are certainly present and are especially difficult to differentiate from domestic pigs in the archaeological record. This is particularly true in the western Mediterranean basin where the local wild boars are particularly small [START_REF] Albarella | Size and shape of the Eurasian wild boar (Sus scrofa), with a view to the reconstruction of its Holocene history[END_REF][START_REF] Evin | Phenotype and animal domestication: a study of dental variation between domestic, wild, captive, hybrid and insular Sus scrofa[END_REF] and where the domestic pigs arrived from the Near East during the Neolithic after genetically admixing with European wild boars all along their route of spread (Frantz et al., 2019). While traditionally, small specimens are identified as domestic pigs (e.g. Albarella et al., 2006b;[START_REF] Rowley-Conwy | Distinguishing wild boar from domestic pigs in prehistory: a review of approaches and recent results[END_REF], here we did not detect a clear group of size, but some measurements were particularly large and likely to belong to wild boar. While it is commonly accepted that the metric distinction of suids is unclear (e.g. Albarella et al., 2006b;[START_REF] Evin | Using traditional biometrical data to distinguish West Palearctic wild boar and domestic pigs in the archaeological record: new methods and standards[END_REF], geometric morphometrics can help address this problem (e.g. [START_REF] Cucchi | New insights into pig taxonomy, domestication and human dispersal in Island South East Asia: molar shape analysis of Sus remains from Niah Caves[END_REF][START_REF] Cucchi | Early pig domestication at Jiahu, Henan Province, China: clues from molar shape analyses using geometric morphometric approaches[END_REF][START_REF] Evin | The long and winding road : identifying pig domestication through molar size and shape[END_REF][START_REF] Evin | Phenotype and animal domestication: a study of dental variation between domestic, wild, captive, hybrid and insular Sus scrofa[END_REF]. Indeed, shape seems to be a much more promising indicator of the domestic/wild status of the specimens than size, especially on dental data [START_REF] Evin | The long and winding road : identifying pig domestication through molar size and shape[END_REF][START_REF] Evin | Phenotype and animal domestication: a study of dental variation between domestic, wild, captive, hybrid and insular Sus scrofa[END_REF] and such approaches will likely be beneficial to further biometric study in the region.

One of the original features of the study presented here is the use of time, not by grouping measurements into chrono-cultural categories, but as a continuous variable. We used the mean of possible time of occupation (mean of the TPQ and TAQ) determined as precisely as possible for each stratigraphic unit of the sites. This approach, more precise than using the average dating of the site (e.g. [START_REF] Frémondeau | Pigs and cattle in Gaul: the role of gallic societies in the evolution of husbandry practices[END_REF][START_REF] Duval | Boeufs gaulois et boeufs français : morphologies animales et dynamiques économiques au cours de La Tène et des périodes historiques[END_REF] or average dating of phase (e.g. [START_REF] Arbuckle | Data sharing reveals complexity in the westward spread of domestic animals across Neolithic Turkey[END_REF][START_REF] Arbuckle | Documenting the initial appearance of domestic cattle in the Eastern Fertile Crescent (northern Iraq and western Iran)[END_REF] is, however, not completely satisfactory as it does not take into account the extent or uncertainty of the occupancy boundaries. In the future, it will be of prime interest to improve this aspect by, for example, applying resampling methods (e.g. bootstrap).

Diachronic evolution

Analyses computed at the scale of the variable have highlighted two main results. First, within a bone, variables do not always show identical diachronic evolution, corresponding either to different trends suggesting allometric differences, or similar trends but shifted in time, suggesting asynchronous evolution. Second, these analyses are strongly and particularly influenced by the sample size, and when the number of measurements is small, a single measurement may have a strong influence on the curve and its confidence interval and particular care must be taken during the interpretations. The analyses of the length, breadth and depth dimensions revealed relatively homogeneous trends except when the number of measurements was relatively low, such as the extremes of the chronological period, or for the goat that was the least well represented species. All measurements considered together, the comparison of the four species revealed different patterns through time.

The evolution of the four species during the Roman Empire in western Gallia Narbonensis can now be discussed separately.

Cattle

Cattle are, by far, the most variable species we studied, with a regular and continuous size increase between the 2nd c. BC (starting point of our study) and early 2nd c. AD. A contemporaneous size increase has been observed in northern Italy [START_REF] Trentacoste | New trajectories or accelerating change? Zooarchaeological evidence for Roman transformation of animal husbandry in Northern Italy[END_REF], Catalonia (Colominas and Sana, 2009;[START_REF] Colominas | The impact of the Roman Empire on animal husbandry practices: study the changes in cattle morphology in the north-east of the Iberian Peninsula through osteometric and ancient DNA analyses[END_REF][START_REF] Colominas | Livestock trade during the early Roman period: first clues from the trading of empúries (Catalonia)[END_REF], throughout Gaul and Germania [START_REF] Duval | Diversité des cheptels et diversification des morphotypes bovins dans le tiers nord-ouest des Gaules entre la fin de l ' ˆage du Fer et la période romaine[END_REF][START_REF] Frémondeau | Pigs and cattle in Gaul: the role of gallic societies in the evolution of husbandry practices[END_REF][START_REF] Duval | Boeufs gaulois et boeufs français : morphologies animales et dynamiques économiques au cours de La Tène et des périodes historiques[END_REF], Switzerland [START_REF] Groot | Market strategies in the Roman provinces: different animal husbandry systems explored by a comparative regional approach[END_REF], Netherlands [START_REF] Groot | Animals in Ritual and Economy in a Roman Frontier Community[END_REF][START_REF] Groot | Barely Surviving or More than Enough[END_REF] and England [START_REF] Albarella | The development of animal husbandry from the Late Iron Age to the end of the Roman period: a case study from South-East Britain[END_REF][START_REF] Rizzetto | Les transformations de l'élevage au début et à la fin de l'époque romaine en Grande Bretagne : questions d'acculturation, d'adaptation et « d'amélioration[END_REF]. This increase seems to be homogeneous in both intensity and duration across Gaul, though some differences in timing have been reported, with cattle of Narbonese Gaul and Italy being already larger than those of Northern Gaul in the 2nd-1st c. BC [START_REF] Frémondeau | Pigs and cattle in Gaul: the role of gallic societies in the evolution of husbandry practices[END_REF]. In Northern Italy, bovine dimensions might have increased since the Bronze Age (Trentacoste et al., 2021). For southern France, the samples from the site of Lattara, which constitute one of the rare references in the region for the transition between Iron Age I & II, suggest an opposite dynamic from Northern Italy with a size decrease during the 5-4th c. BC [START_REF] Nieto-Espinet | Livestock production, politics and trade: a glimpse from Iron age and roman Languedoc[END_REF].

After reaching a maximum at the beginning of the 2nd c. AD, overall cattle size slightly decreased until the end of the 2nd c. AD to reach what looks like a plateau until the end of the period. This stability of LSI during Late Antiquity has been observed in Switzerland, while LSI decrease in the Netherlands [START_REF] Groot | Market strategies in the Roman provinces: different animal husbandry systems explored by a comparative regional approach[END_REF].

However, this result is mitigated by the analyses separating the bone dimensions. In fact, during the 3rd and 4th c. AD, while LSI-length and LSI-breadth remain stable from the middle of the 2nd to the end of the 4th c. AD, a decrease of LSI-depth is observed from the second half of the 2nd c. AD, a fact that was previously unknown in this region but which coincides with recent observations in Northern Italy [START_REF] Trentacoste | New trajectories or accelerating change? Zooarchaeological evidence for Roman transformation of animal husbandry in Northern Italy[END_REF]. In comparison, in Gaul, only a fall in the length of bovine bones had been observed from the 3rd c. AD [START_REF] Duval | Boeufs gaulois et boeufs français : morphologies animales et dynamiques économiques au cours de La Tène et des périodes historiques[END_REF], a result not observed here. In Catalonia [START_REF] Nieto-Espinet | Resilience and livestock adaptations to demographic growth and technological change: a diachronic perspective from the Late Bronze Age to Late Antiquity in NE Iberia[END_REF], only bone lengths decrease from Late Antiquity while widths remain stable until the 5th c. AD.

Cattle appeared to be the species with greatest variation between bones and between variables within a bone. For example, the variables of the scapula show a size increase followed by a decrease. For some others, like the metapods, variables show a size increase followed by what seems to be a relative stability even if the confidence intervals are particularly large. This reveals different allometries, where not all bones evolve homogeneously over time. In addition, the scapula provides another example of allometries, with asynchronous evolution of its different measurements. While the greatest length of the processus articularis (GLP) and breadth of the glenoid cavity (BG) reached their maximum around year 0, the collum scapulae (SLC) reached his maximum nearly two centuries later. A consequence of these allometry is that the trend observed by bone does not necessarily reflect the diachronic size evolution depicted by the LSI. The detection of allometry, between bones and between variables appeared however greatly influenced by the number of measurements.

In cattle, we identified differences between LSI-depth on the one hand, and LSI-length and LSI-breadth on the other hand, especially in the metapods. In northern Italy and England, only their breadths would decrease after the 4th c. AD, implying a drop in the bones robustness [START_REF] Rizzetto | Les transformations de l'élevage au début et à la fin de l'époque romaine en Grande Bretagne : questions d'acculturation, d'adaptation et « d'amélioration[END_REF][START_REF] Trentacoste | New trajectories or accelerating change? Zooarchaeological evidence for Roman transformation of animal husbandry in Northern Italy[END_REF]. This allometric trend was also identified in Languedoc, with only the length of the metapods decreasing around the 6th-7th c. AD, while the breadth decreased earlier, around the 4th-5th c. AD [START_REF] Mureau | Consommation et exploitation des ressources animales en Auvergne et en Languedoc de l'Antiquité tardive au haut Moyen ˆAge[END_REF].

The bovine metatarsal deserves special attention, as it has been the subject of multiple syntheses for the French area (Forest andRodet-Belarbi, 1998, 2002;[START_REF] Carrère | Osteometry and shifts in the bovine population in France[END_REF]. In the synthesis of Forest and Rodet-Belarbi (2002), the length of the metatarsal increases during Antiquity from approximately 214 (50 BC to 70 AD) to 230 mm (2nd-6th c. AD), which would represent a range of 0.031 in LSI values, a difference that could not be confirmed by our study due to the large confidence interval we observed. However, despite this uncertainty, metatarsal and metacarpal lengths differ between the beginning and the end of our studied period, confirming these preliminary finds.

Suids

In suids, the three bone dimensions show similar patterns, except at the end of the period where less measurements were available. Compared to cattle, the range of variation in suid size is relatively small during the period. While all dimensions increase during the 1st c. BC and then seem to remain stable for a century, the breadth and depth show a small and brief increase until the first quarter of the 2nd c. AD. Then, only the breadth shows a slight and continuous decrease for the rest of the period, while for the two other dimensions the confidence intervals are large but the size seems to increase.

This increase in pig size can be traced back to the 4th c. BC in southern France [START_REF] Duval | Evolution et diversité de la forme du cochon entre l'âge du Fer et la période moderne en Gaule et en France. Régionalisme, acquisitions zootechniques et implications historiques[END_REF]. In Northern Italy, an increase has also been identified in LSI-breadth between the Iron Age and Roman period in the North [START_REF] Trentacoste | New trajectories or accelerating change? Zooarchaeological evidence for Roman transformation of animal husbandry in Northern Italy[END_REF], and in LSI-length between the Republican and Imperial periods in central Italy (De Grossi Mazzorin and Minniti, 2017), while no variation in size can be noted in Catalonia [START_REF] Colominas | Roman conquest and changes in animal husbandry in the north-east of the Iberian Peninsula: searching for patterns, and singularities[END_REF].

At the larger scale of the Gaul, limb bone lengths increased from the end of the 3rd c. BC, with regional variations in the intensity and duration of the increase [START_REF] Frémondeau | Pigs and cattle in Gaul: the role of gallic societies in the evolution of husbandry practices[END_REF]. Gallia Narbonensis appears to be the first region to show its maximal average pig size, around 200 AD [START_REF] Frémondeau | Pigs and cattle in Gaul: the role of gallic societies in the evolution of husbandry practices[END_REF], slightly later than what we observed in our study, a difference that may be due to the geographic diversity of the studied sites or the different methodology we used. The maximal average pig size appeared smaller in Narbonensis than in other Gaul territories where the increase appeared more intense and spread over a longer period of time [START_REF] Frémondeau | Pigs and cattle in Gaul: the role of gallic societies in the evolution of husbandry practices[END_REF]. Then, the size decrease we observed seemed to continue at least until around the 10th c. AD [START_REF] Duval | Evolution et diversité de la forme du cochon entre l'âge du Fer et la période moderne en Gaule et en France. Régionalisme, acquisitions zootechniques et implications historiques[END_REF][START_REF] Mureau | Consommation et exploitation des ressources animales en Auvergne et en Languedoc de l'Antiquité tardive au haut Moyen ˆAge[END_REF].

Caprines

Sheep and goat cannot always be identified in the archaeological record, and in the Western Mediterranean area sheep very often outnumber goats, though some exceptions exist (Forest, 1997(Forest, , 1999;;Forest et al., 2004). As a consequence, the number of measurements available for goats is relatively small and the obtained results should be specified with more data.

The size variation of the two species appeared limited, at least when compared to the variation in cattle.

Altogether the LSI values increase for both species in the 1st c. BC, and then remain relatively stable until the end of the 2nd c. AD. Analysis by dimensions shows that only breadths increase in sheep during the 2nd-1st c. BC while in goats both breadths and depths increased during the same period. In the absence of an evolution in length, only the robustness and not the height of these two species seems to increase during the first centuries of the Roman period. Then, sheep sizes begin to increase while goat sizes seem to decrease between the 2nd and the 4th c. AD. However, the data are, again, particularly scarce for this period and should be interpreted with caution.

The trends we observe appear to be therefore congruent with a previous synthesis in Languedoc (Forest, 2008), where increases in the breadths of humerus, radius and metacarpus were recorded between the 3rd c. BC and the 2nd c. AD, whereas the distal breadth of the tibia did not change throughout the same period. In Catalonia, a size increase from the end of the 3rd c. BC has also been shown [START_REF] Colominas | Roman conquest and changes in animal husbandry in the north-east of the Iberian Peninsula: searching for patterns, and singularities[END_REF]. In addition, the site of Lattara revealed a significant increase in caprine sizes between the 5th and 4th c. BC, followed by a stability in size until the 2nd c. AD [START_REF] Nieto-Espinet | Livestock production, politics and trade: a glimpse from Iron age and roman Languedoc[END_REF]. It is therefore possible that the increase we observed started at least between the first and second Iron Age.

During Late Antiquity, our results appeared incongruent with previous studies. While we observed a size increase through the period, a size decrease had previously been recorded for the period in Languedoc (Forest, 2008;[START_REF] Mureau | Consommation et exploitation des ressources animales en Auvergne et en Languedoc de l'Antiquité tardive au haut Moyen ˆAge[END_REF]. A size decrease has also been observed in breadth, but not length, measurements in Northern Italy [START_REF] Trentacoste | New trajectories or accelerating change? Zooarchaeological evidence for Roman transformation of animal husbandry in Northern Italy[END_REF]. Conversely in Central Italy, an increase in ovine bone length between the Imperial period and Late Antiquity has been shown [START_REF] Grossi Mazzorin | Changes in lifestyle in ancient rome (Italy) across the Iron age/roman transition[END_REF]. Further studies are therefore needed to confirm caprine size evolution during Late Antiquity, not only in Languedoc but also in adjacent areas where different trends have been recorded.

Lines for future research

Our analyses provide a detailed and critical description of the different variables analysed and use a diachronic statistical representation coupled with confidence intervals. We detected subtler diachronic variation allowed by a higher temporal accuracy than. large chronocultural phases, and to visually inspect its statistical significance. This work confirms that LSI approaches provide valuable information when studying large-scale size variation over large time periods. It also highlights different trends between variables, bones, or between breath, length and depth dimensions among bones and, thus, underlines the importance of bone-based or variable-based analyses especially for allometry detection.

Several points should be considered for future research such as the category of the site, the climate and geography, and a larger time range.

Socio-cultural characteristics

While all sites were analysed together, the nature of their occupation was not homogeneous. These socioeconomic differences may be reflected in animal husbandry practices and animal bones.

In northern Gaul, from the end of the 1st c. BC to the 4th c. AD, bovine remains discovered in rural contexts are on average larger than in towns [START_REF] Oueslati | Approche socio-économique et culturelle de la ville gallo-romaine de Lutèce[END_REF][START_REF] Duval | Diversité des cheptels et diversification des morphotypes bovins dans le tiers nord-ouest des Gaules entre la fin de l ' ˆage du Fer et la période romaine[END_REF]. Other studies of assemblages from the ancient city centres of Lodeve (Forest, 2019) and Nimes [START_REF] Forest | Eléments archéozoologiques[END_REF], also noted lower bovine measurements than those originating from rural settlements. This is also true for pigs during the final La Tene period in northern Gaul, where remains from rural sites show the largest dimensions, while from the 2nd c. AD onwards the largest values are mostly from urban centres and villae [START_REF] Duval | Evolution et diversité de la forme du cochon entre l'âge du Fer et la période moderne en Gaule et en France. Régionalisme, acquisitions zootechniques et implications historiques[END_REF]. This larger size of pigs in urban contexts has also been noted in Italy [START_REF] Mackinnon | High on the hog: linking zooarchaeological, literary, and artistic data for pig breeds in roman Italy[END_REF] with less size variation than in rural contexts. Finally, the culture of an occupation can also influence the size of domestic animals. In Catalonia, the so-called Romanization period, between the end of the 3rd and the 1st c. BC, is characterized by a significant difference in bovine and ovine bone dimensions between settlements, with higher values among newly-created settlements than among occupations perpetuated since the Middle Iberian period [START_REF] Colominas | Roman conquest and changes in animal husbandry in the north-east of the Iberian Peninsula: searching for patterns, and singularities[END_REF].

Climate and environment

Climate and environment are important parameters to consider, especially in long-term and global studies (e.g. [START_REF] Duval | Did Romanization impact Gallic pig morphology? New insights from molar geometric morphometrics[END_REF][START_REF] Marom | Zooarchaeology of the social and economic upheavals in the late antique-early islamic sequence of the negev desert[END_REF][START_REF] Nieto-Espinet | Resilience and livestock adaptations to demographic growth and technological change: a diachronic perspective from the Late Bronze Age to Late Antiquity in NE Iberia[END_REF]. They both play an important role in determining body size (e.g. [START_REF] Davis | The effects of temperature change and domestication on the body size of Late Pleistocene to Holocene mammals of Israel[END_REF]. It therefore seems important to take into account climate fluctuations in the context of a broader biometric study, but also the different environments that can impact body mass. This would require palaeoclimatic reconstructions dedicated to the study area.

Geography

Regional differences have been reported in the evolution of domestic animals [START_REF] Duval | Diversité des cheptels et diversification des morphotypes bovins dans le tiers nord-ouest des Gaules entre la fin de l ' ˆage du Fer et la période romaine[END_REF][START_REF] Duval | Evolution et diversité de la forme du cochon entre l'âge du Fer et la période moderne en Gaule et en France. Régionalisme, acquisitions zootechniques et implications historiques[END_REF][START_REF] Duval | Boeufs gaulois et boeufs français : morphologies animales et dynamiques économiques au cours de La Tène et des périodes historiques[END_REF][START_REF] Mureau | Consommation et exploitation des ressources animales en Auvergne et en Languedoc de l'Antiquité tardive au haut Moyen ˆAge[END_REF] and more in depth analyses of size variation may also reveal microregional variation. For example, the evolution of herd stature seen in the lowlands of northern Italy has not been observed in the alpine regions [START_REF] Mackinnon | Production and Consumption of Animals in Roman Italy: Integrating the Zooarchaeological and Textual Evidence[END_REF] and this has been interpreted as a characteristic of sheep breeds that are particularly constrained to this extreme environment [START_REF] Mason | Mediterranean breeds of cattle, sheep and goats[END_REF][START_REF] Hall | Livestock Biodiversity: Genetic Resources for the Farming of the Future[END_REF]. Other territories, although integrated into the Roman Empire, may also have experienced the same limitations to their livestock sizes, such as the west of Britain [START_REF] Maltby | Iron Age, Romano-British and Anglo-Saxon animal husbandry a review of the faunal evidence[END_REF][START_REF] Hammon | Romano-British Early Medieval Socio-Economic and Cultural Change: Analysis of the Mammal and Bird Bone Assemblages from the Roman City of Viroconium Cornoviorum[END_REF] or Santarem in central Portugal [START_REF] Davis | Faunal remains from Alcacova de Santarem[END_REF].

Time

Our study focused on the Roman period in Narbonese Gaul, between the 2nd c. BC and the 4th c. AD. A complementary study of bone dimensions of these species must be carried out between the 5th and 1st c. BC in order to discover the origin of their increase, and their link with a possible Roman influence. Although most of our observations agree with the conclusions of previous studies, the increase in ovine dimensions during Late Antiquity is an original discovery. It deserves to be further investigated with a larger sample of remains from the 2nd-6th c. AD to confirm its significance as well as its durability through Medieval Times.

CONCLUSION

Whatever the species considered, the increase in bone size at the beginning of the Roman Empire is a long dynamic, inscribed over tens or even hundreds of animal generations. Its beginning could be clearly prior to the 2nd c. BC and therefore calls for a continuation of this work on the Bronze Age and Iron Age periods [START_REF] Valenzuela-Lamas | Animal husbandry across the western roman Empire: changes and continuities[END_REF][START_REF] Nieto-Espinet | Livestock production, politics and trade: a glimpse from Iron age and roman Languedoc[END_REF][START_REF] Trentacoste | New trajectories or accelerating change? Zooarchaeological evidence for Roman transformation of animal husbandry in Northern Italy[END_REF]. In any case, the duration of this size increase is at least two centuries for pig, goat and sheep, and over three centuries for cattle.

From the 2nd c. AD onwards, each taxon follows a distinct morphological evolution. Cattle and goats tend to fall in size until the end of the sequence, while pigs remain at the same height (LSI-lengths), but more slender (decrease in LSI-breadths). Sheep are the only taxon whose bone size continues to increase, following a stagnation during the 1st and 2nd c. AD.

The four species present different diachronic size changes that may result from different agropastoral or environmental conditions. It has been proposed that these changes in domestic animals were linked to the end of the Roman Empire (e.g. [START_REF] Leguilloux | L'élevage en Narbonnaise et en Gaule du Nord : continuités ou ruptures[END_REF][START_REF] Duval | Evolution et diversité de la forme du cochon entre l'âge du Fer et la période moderne en Gaule et en France. Régionalisme, acquisitions zootechniques et implications historiques[END_REF][START_REF] Rizzetto | Les transformations de l'élevage au début et à la fin de l'époque romaine en Grande Bretagne : questions d'acculturation, d'adaptation et « d'amélioration[END_REF]. However, because size evolved over a long duration, over centuries, it seems challenging, or even impossible, to link these changes to specific events. To which extent a transition of the pastoral model can be a sufficient explanation for the changes observed remain unknown [START_REF] Audoin-Rouzeau | La Taille du cheval en Europe de l'Antiquité aux temps modernes[END_REF]Forest and Rodet-Belarbi, 2002;[START_REF] Duval | Boeufs gaulois et boeufs français : morphologies animales et dynamiques économiques au cours de La Tène et des périodes historiques[END_REF][START_REF] Mureau | Consommation et exploitation des ressources animales en Auvergne et en Languedoc de l'Antiquité tardive au haut Moyen ˆAge[END_REF], but it seems unlikely that both the Roman conquest and its fall could have had a sudden and major impact on domestic species. The causes of the observed trends therefore remain to be investigated and are certainly multimodal. Only micro-regional studies, comparing multiple socio-economic contexts, a careful exploration of environmental conditions through time, and taking into account the time as accurately as possible will allow the tracking and understanding of distinct morphological trajectories. The concrete contribution that continuous diachronic analysis is able to offer to osteometric syntheses is undeniable and offers much promise. This time-restricted study will be extended within the framework of the DEMETER project (ERC #852573) that aims to understand how and why domestic species change over the eight last millennia in the north western occidental Mediterranean basin. <SI Table 1> Information on the archaeological sites studied. Site names and their city of origin. Terminus post quem (T.P.Q.) and terminus ante quem (T.A.Q.) of the studied stratigraphic units and number of biometric measurements per species. The number (n) refer to those on the maps of figure 1.

Fig. 1 .

 1 Fig. 1. Location of the archaeological assemblages studied through time, from the 2nd century BC to the 4th century AD. Information on the sites, identified by the numbers, can be found in S1Table 1. The grey lines represent the current borders of French departments.

Fig. 2 .

 2 Fig. 2. Evolution through time (200 BCE to 400 AD) of the Log Size Index (LSI) values separated per bone and variables and for each taxon separately (A = Cattle, B = Suids and C = Sheep). Only the four bones with the largestnumber of measurements are presented (all others are shown in SI Fig.2). Only the variables with at least 30 measurements are presented. Goats were not analysed due to the small sample size per variable. Each point corresponds to a LSI value plot in y against time in x. The sample size per bone (n = ) is written in brackets.Abbreviations are those of von den Driesch(1976).

Fig. 4 .

 4 Fig. 4. Log Size index evolution forcattle, suids, goat and sheep between 200 BCE and 400 AD. All variables measured on the appendicular skeleton with more than 2 measurements were included. Each point corresponds to a LSI value plot in y against time in x. The sample size per species (n = ) is written in brackets.

Fig. 5 .

 5 Fig. 5. Intra-specimen LSI variation. A. Visualization of intra-specimen Log Size Index (LSI) variation compared to the diachronic evolution of the species. Each dot represents a LSI value and are coloured by species. Values belonging to single specimens are aligned in x. The curves are those obtained in Fig. 4 (i.e. all values used for their computation are not represented). B. Ranges of LSI values calculated from the remains of 23 individuals separated by taxon. The size of the dots represents the number (Nb.) of available measurements and the colour reflects time. Data available in SI table 5. (For interpretation of the references to colour in this figure legend, the reader is referred to the Web version of this article.)

Table 1 .

 1 The grey lines represent the current borders of French departments.

ACKNOWLEDGMENTS

We gratefully thank Angela Trentacoste, Silvia Valenzuela-Lamas and Ariadna Nieto Espinet, Silvia Guimarães, Jose Pozo for organising the Zooarchaeology Interconnected Mediterranean workshop. This work was supported by the European Research Council (ERC) under the European Union's Horizon 2020 research and innovation program (grant agreement No. 852573). We thank the reviewers for their comments, which have helped improve this paper.

AUTHOR CONTRIBUTIONS

DECLARATION OF COMPETING INTEREST

The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.

SUPPLEMENTARY INFORMATION

<SI figure 1>: Description of the unpublished measurements used in this study

<SI figure 2 >: Log Size index evolution by taxa (A= Cattle, B= Suids and C= Sheep/Goat), bones and variables between 200BC et 400 AD. Only appendicular skeleton measurements where there is than 30 measurements per variables are presented. Goat Log Size Index evolution is not available because of a lack of data. Each point corresonds to a measurment dated by the mean of TPQ/TAQ of its stratigraphic unit.


domain: sde chim sdv

text:
Maëva Marimoutou

Gilles Bareille

Mathieu Milhe-Poutingon

Patrick Baldoni-Andrey

Amiel Boullemant

Cecile Courreges

Clémentine Gelber

Sandra Mounicou

Hélène Tabouret

Séverine Le Faucheur

Amiel Boulle

Accumulation and chronic effects of cobalt on the gastropod Radix balthica

de documents scientifiques de niveau recherche, publiés ou non, émanant des établissements d'enseignement et de recherche français ou étrangers, des laboratoires publics ou privés.

Accumulation and chronic effects of cobalt on the gastropod Radix balthica

MATERIALS AND METHODS

• The present study demonstrates the impact of Co on the reproduction of R. Balthica. A delay in hatching was observed in Co-exposed gastropods. This delay is dependent of exposure Co concentration with a minimum effect at higher Co concentrations. The number of neonates is much lower at the higher Co concentrations. • Co did not show a negative impact on the shell growth at the micrometer level.

• Co mainly distributes in the external shell surfaces. Shell Co accumulation was already measured at the end of the first week of exposure and no further increase was observed with longer exposure time. Future analysis of Co accumulation in the gastropod soft bodies as a function of time will allow us to better understand Co pathway from water to the shell and to assess the potential use of gastropod shells as bioindicator of metal contamination.

Gastropods are widespread mollusks living at the bottom and in shallow water of freshwater systems. First consumers of periphyton and plants, they represent an important source of food for large crustacean and fish. Toxic effects due to contamination such as an increase in metal would thus impede food sustainability of ecosystems. Gastropod shells have the interesting feature of growing throughout their life by integrating some of the chemical elements present in their environment, including metals.

In this study, cobalt (Co) is the metal of interest due to its increasing use in recent technologies of transport or energy storage

1

  1 , G. Bareille 1 , M. Milhe-Poutingon 1 , P. Baldoni-Andrey 2 , A. Boullemant 3 , C. Courrèges 1 , C. Gelber 2 , S. Mounicou 1 , H. Tabouret 1 , S. Le Faucheur 1 Université de Pau et des Pays de l'Adour, E2S-UPPA, CNRS, IPREM, Chaire Ecotox, Pau, France; 2 TotalEnergies, Pole d'Études et de Recherche de Lacq, France; 3 Rio Tinto Closure, France (Email: maeva.marimoutou@univ-pau.fr) Once a week • Physicochemical parameters : Conductivity, pH, oxygen and turbidity • Water analysis : Anion, cation and dissolved organic matter concentrations • Organism analysis : Shell measurements (length and width) and number of egg masses • Shell analysis : Microchemical analyses of metals in the shells performed using LA-ICP-MS Exposure conditions • 28 days in June 2021 • 4 studied Co concentrations : 0.7 ± 0.2 μg.L -1 (control), 2.4 ± 0.8 μg.L -1 , 24.1 ± 0.8 μg.L -1 and 56 ± 17 μg.L -1 • 3 boxes of 32 organisms of Radix balthica collected in situ placed in each artificial stream • Sampling at D0, D7, D14, D21 and D28

•

  (3) . Laser Ablation Inductively Coupled Plasma Mass Spectrometry (LA-ICPMSmicrometer scale) was used to explore the variability of metals in shells with two objectives : to TotalEnergies at Lacq for allowing us to perform our experiments on their site. All members of Chair Ecotox and TotalEnergies helped with field preparation and sampling, especially S.Sebihi, J.M Dalens, F. Mounede, C. Pillitteri. (1) Checa AG, Frontiers in Marine Science, 2018 (2) Marin F, Le Roy N,Benjamin M, Frontiers in Bioscience, Significant increase in shell Co concentration was observed from 2.4 µg/L Co at Day 7 No further increase was observed at longer exposure time • Shell Co concentration further increased at 24.1 µg/L. A plateau was measured at 56 µg/L Co

•

  H 2 O 2 (2%) during 12h Shell measurements Shell fixed in epoxy resin for imaging analysis of shell section 1 replicate per concentration at day 28 • In control, Co distributed evenly in the shell at very low concentration (<1µg/g) • At all exposure concentrations, higher Co concentration mainly found on the shell external surface • At the 24.1 and 56 µg/L, shell Co concentrations were high at both internal and external surfaces A) Co distribution in shell by mass-spectrometry imaging at Day 28 R1 Direction of ablation Analysis within a single growth ridge External surface : recent part IR 1030 nm femtosecond laser ablation coupled to an Agilent 8900 ICP-MS Triple Quad • No effect of Co concentrations was found on the shell length (p>0.05) • Similar results were obtained for the width (p>0.05; data not shown) • Growth in length and width only between day 0 and day 7 Number of neonates decreased with Co concentration • Probably due to delay in the hatching time • Mortality increased significatively at Day 28 (p<0.05) • No significant mortality induced by Co exposure concentration