In mammals, complex dental microwear textures (DMT) representing differently sized and shaped enamel lesions overlaying each other have traditionally been associated with the seeds and kernels in frugivorous diets, as well as with sclerotized insect cuticles. Recently, this notion has been challenged by field observations as well as in vitro experimental data. It remains unclear to what extent each food item contributes to the complexity level and is reflected by the surface texture of the respective tooth position along the molar tooth row. To clarify the potential of seeds and other abrasive dietary items to cause complex microwear textures, we conducted a controlled feeding experiment with rats. Six individual rats each received either a vegetable mix, a fruit mix, a seed mix, whole crickets, whole black soldier fly larvae, or whole day-old-chicks. These diets were subjected to material testing to obtain mechanical properties, such as Young’s modulus, yield strength, and food hardness (as indicated by texture profile analysis [TPA] tests). Seeds and crickets caused the highest surface complexity. The fruit mix, seed mix, and crickets caused the deepest wear features. Moreover, several diets resulted in an increasing wear gradient from the first to the second molar, suggesting that increasing bite force along the tooth row affects dental wear in rats on these diets. Mechanical properties of the diets showed different correlations with DMT obtained for the first and second molars. The first molar wear was mostly correlated with maximum TPA hardness, while the second molar wear was strongly correlated with maximum yield stress, mean TPA hardness, and maximum TPA hardness. This indicates a complex relationship between chewing mechanics, food mechanical properties, and observed DMT. Our results show that, in rats, seeds are the main cause of complex microwear textures but that hard insect body parts can also cause high complexity. However, the similarity in parameter values of surface textures resulting from seed and cricket consumption did not allow differentiation between these two diets in our experimental approach.

Les restes fossiles des grands herbivores (genres Bos, Bison, Equus, Coelodonta et Stephanorhinus) sont abondants dans les séquences archéo-paléontologiques du Pléistocène moyen et supérieur du Sud de la France. L’étude biométrique des restes osseux et dentaires à partir de 11 sites (Camp-de-peyre, La Micoque, Igue des Rameaux, Payre, Lunel-Viel, Rigabe, Suard, Combe-Grenal, Pech de l’Azé II, Coudoulous II, Peyre) et 22 ensembles/niveaux, contrôlée par des analyses statistiques factorielles, permet de caractériser les adaptations contextuelles de chaque taxon et leurs tendances évolutives, et d’affiner leurs apports biochronologiques. Les analyses de méso- et micro-usure dentaire détaillent les comportements alimentaires de ces taxons et les environnements locaux dans lequel ils vivaient, intégrant les variations saisonnières. L’utilisation des deux approches, biométriques et écométriques, augmente significativement notre résolution des contextes paléo-environnementaux, pour chacun des sites étudiés. Notre étude apporte de nouvelles données sur les modes d’adaptation tant anatomiques qu’éco-éthologiques des grands ongulés. Des conclusions sur la gestion des territoires par ces herbivores mais aussi sur leurs exploitations par leurs prédateurs, humains et non-humains, ont également été possibles. Nous avons ainsi mis en évidence des stratégies de prédation et d’acquisition originales, notamment centrées sur certains taxons (Equus) pour les groupes de Pré-Néandertaliens du Sud de la France opérant dans un rayon d’action plus important que celui d’autres prédateurs (en particulier hyènes). / The fossil remains of large herbivores (genus Bos, Bison, Equus, Coelodonta and Stephanorhinus) are frequent in the archaeo-paleontological record in the South of France during the Middle and Late Pleistocene. The biometrical study of bones and teeth remains from 11 sites (Camp-de-peyre, La Micoque, Igue des Rameaux, Payre, Lunel-Viel, Rigabe, Suard, Combe-Grenal, Pech de l’Azé II, Coudoulous II, Peyre) and 22 bone ensembles/layers, consolidates by factorial statistical analysis, allow us to define the degree of contextual adaptation and the evolutionary trend of each taxon which in turn refine their biochronological contribution. Diet habit of each taxon, local environments and seasonal variations are documented by dental meso- and micro-wear studies. Thanks to these two combined approaches, biometrical and ecometrical, we were able to significantly increase our knowledge about the paleoenvironmental context of each studied site. Our study brings new data about anatomical and ethological studied of large ungulates. We also display new results about the territory management by herbivores and then on their relationships with predators, human and non-human. Thus, we highlight Pre-Neandertalian original predation and acquisition strategies in South of France focusing on one species (Equus) in a territorial range larger than other carnivores’ (such as hyenids).

Dans le but d’étudier la santé dentaire d’une partie de la population du cimetière Saint-Antoine (1799-1854), 105 individus ont été analysés pour la première fois avec une approche très détaillée. Cette approche nous a permis d’explorer des variations possibles entre les diverses catégories d’une population urbaine grandissante au début de l’industrialisation. Les pathologies dentaires à l’étude étaient la carie, l’usure dentaire, l’hypoplasie de l’émail, le tartre ainsi que quelques pathologies complexes (pathologies associées à la carie, à l’étiologie traumatique et parodontale et des formations tumorales). La question centrale était de voir s’il y a des différences au niveau de ces variables paléopathologiques entre les hommes (38) et les femmes (43) de l’échantillon, mais également entre les adultes (90) et les juvéniles (15). Les résultats nous montrent que la plupart du temps, la santé dentaire ne varie pas de manière significative en fonction du sexe. Cependant, quelques tests ont montré des différences, lorsque l’on compare la fréquence des caries selon le type de dent précis, notamment la dent 37 (gM2) qui était plus affectée chez les femmes (20%) que les hommes (13%). La position de la carie sur la dent était également significativement différente entre les sexes : pour la jonction émail-cément (J.E.C.), les hommes étaient plus affectés (52%) que les femmes (32%). L’hypoplasie sévère semblait aussi affecter davantage les femmes (18%) que les hommes (2%). Finalement, les juvéniles ne présentaient presqu’aucune pathologie dentaire. En effet, pour les caries, 80% des juvéniles n’avaient pas de caries, alors que seulement 10% des adultes n’étaient pas touchés. Des différences se sont révélées particulièrement significatives entre les juvéniles et les adultes pour diverses pathologies (caries, tartre, hypoplasie de l’émail) et sur les dents suivantes : 27 (gM2), 37 (gM2), 36 (gM1) et 47 (dM2). Au niveau de la dentition postérieure, cette recherche a donc permis de relever une santé légèrement plus détériorée chez les femmes que les hommes, ainsi qu’une augmentation des pathologies avec l’âge, faits qui concordent avec la littérature générale. Un échantillon plus grand permettrait de vérifier si ces résultats reflètent réellement des différences sanitaires en lien avec divers facteurs (ex. alimentation, hygiène, fertilité) et autres traces de maladies (ex. pathologies osseuses). / To study the dental health of a portion of the population from the Saint-Antoine cemetery (1799-1854), 105 individuals were analyzed for the first time using a detailed approach. This approach permitted us to study the possible variations between categories from an urban and pre-industrialised population. The dental pathologies under study were cavities, dental wear, enamel hypoplasia, dental calculus, and other complex dental pathologies (periodontal diseases, traumatic dental diseases, and dental cysts). The main objective is to find if there are palaeopathological differences between the men (38) and women (43) of the sample, but also if we can notice trends between the juveniles (15) and adults (90). The results show that in terms of general dental health, the men and women of the sample do not show significant differences. However, a few statistic results showed differences, especially when we compare the cavities on specific teeth. Indeed, tooth 37 (second left lower molar) was most affected in the women`s sample (20%) compared to the men’s sample (13%). Another significant result was for the cavity when situated on the cemento-enamel junction, the men were significantly more affected (52%) than women (32%). The last significant result was for the category « severe hypoplasia » and the women were more affected (18%) than men (2%). Finally, almost all the juveniles did not show signs of dental pathologies. In fact, 80% of the adults were affected by cavities whereas only 20% of the juveniles were affected. Also, almost all the pathologies were absent in the juvenile sample, while they were much more represented in the adult sample. The pathologies that affected the adults were: dental cavities (four teeth in particular, 27 (second left upper molar), 37 (second left lower molar), 36 (first left lower molar) and 47 (second right lower molar)), dental calculus and enamel hypoplasia. This research has allowed us to note subtle differences regarding the posterior dentition between the men and women, as well as significant differences between the adults and non adults of the sample, which is consistent with the literature. A bigger sample would allow us to verify if these results really reflect sanitary differences related to multiple factors like diet, hygiene and fertility as well as other pathologies (bone pathologies).