New quantitative method for dental wear analysis of small mammals.

The application of dental wear study to murids has always been ruled out because of their omnivorous diet, which does not leave significant wear on the dentition. Nevertheless, in our work we select Apodemus sylvaticus (wood mouse) as the object of study for several reasons: its seasonal diet, its ability to resist the gastric juices of predators, the fact that it has not undergone major morphological changes since its appearance 3 million years ago, and its widespread distribution throughout much of Europe and part of Africa. The importance of this work lies in the modifications we make to the dental wear methodology for its application to murids. These enable us to obtain quantitative data on the entire tooth surface. The sample chosen was a total of 75 lower first molars from two different archaeological sites: Teixoneres cave and Xaragalls cave. The chronology of the samples chosen ranges from Marine Isotope Stages 5-3. The data obtained reveal that the part of the tooth that shows most wear is the distal part (entoconid). Furthermore, the results provide us with relevant information on the types of accumulations of remains in the caves (short vs. long term), as well as on the seasonality of Neanderthal occupations during the Upper Pleistocene (MIS5-3) of the northeastern Iberian Peninsula.

Speciated mechanism in Quaternary cervids (Cervus and Capreolus) on both sides of the Pyrenees: a multidisciplinary approach.

Cervids, and especially the red deer Cervus elaphus, are among the most regularly and abundantly recorded ungulates in Pleistocene/Paleolithic bone assemblages. Numerous Pleistocene or Holocene subspecies have been described, reinforcing their status as essential proxies for environmental and chronological reconstructions. Despite this, at the beginning of the Late Pleistocene, their diversity seems to have decreased. In this study, we analysed teeth and some postcranial elements of Cervus and Capreolus from north-eastern Iberia and south-eastern France to clarify their morphological characteristics and ecological adaptations. We describe a transitional form in north-eastern Iberia between the western European stock and the current form C. e. hispanicus. Such sub-speciation processes are connected to biogeographical factors, as there were limited exchanges between north-eastern Iberia and the northern Pyrenees, whereas the north-western part of the peninsula seems more connected to the northern Pyrenees. The anatomical plasticity (morpho-functional adaptation and body size) of red deer is connected to dietary flexibility (dental meso- and microwear). Conversely, Capreolus shows greater morphological and ecological homogeneity. Body size variations seem directly correlated with their ability to browse throughout the year. The marked differences between the eco-bio-geographical responses of the two taxa can be explained by their habitat selection.

Abundance or stress? Faunal exploitation patterns and subsistence strategies: The case study of Brush Hut 1 at Ohalo II, a submerged 23,000-year-old camp in the Sea of Galilee, Israel.

The submerged site of Ohalo II was occupied during the Last Glacial Maximum (LGM), between 23,500-22,500 cal BP, bridging the Upper Paleolithic/Epipaleolithic transition in the southern Levant. The site is known for the excellent preservation of its brush huts and botanical remains. This study examines the behavior of its past inhabitants through analysis of the entire faunal assemblage found on the three successive floors of Brush Hut 1. Furthermore, it provides an opportunity to test differing models of prey choice and assess whether the observed resource diversification is the result of resource depression (explained by Optimal Foraging Theory) or resource abundance (explained by Niche Construction Theory). We focused on a quantitative, qualitative and spatial investigation of the more than 20,000 faunal remains, combining traditional zooarchaeological methods with microwear analysis of teeth and Fourier Transform Infrared Spectroscopy (FTIR) of burnt bones. Identification of faunal remains to the most detailed level possible, combined with analysis of skeletal element frequencies allowed reconstruction of a profile of the desired prey, highlighting the importance of small, expedient prey compared to larger game (ungulates). FTIR was used to identify degrees of burning and to develop a key to identifying burnt bones from water-logged environments. Availability of multiple food sources within a rich habitat may have driven exploitation of those varied local resources, rather than targeting energetically-rich large prey. The choice of a littoral habitat that could be intensively exploited is an example of niche selection. Comparison with contemporaneous and later sites contributes to the ongoing discussion about Early Epipaleolithic prey choice, and the impact, if any, of the LGM in the Jordan Valley. Ohalo II is an example of diverse prey choice motivated by abundance rather than stress, at a 23,000-year-old fisher-hunter-gatherers camp.

Examining Neanderthal and carnivore occupations of Teixoneres Cave (Moià, Barcelona, Spain) using archaeostratigraphic and intra-site spatial analysis.

Teixoneres Cave (Moià, Barcelona, Spain) is a reference site for Middle Palaeolithic studies of the Iberian Peninsula. The cave preserves an extensive stratigraphic sequence made up of eight units, which is presented in depth in this work. The main goal of this study is to undertake an initial spatial examination of Unit III, formed during Marine Isotope Stage 3, with the aim of understanding spatial organization and past activities developed by Neanderthals and carnivores (bears, hyenas and smaller carnivores). The total sample analysed includes 38,244 archaeological items and 5888 limestone blocks. The application of GIS tools allows us to clearly distinguish three geologically-defined stratigraphic subunits. Unit III has been previously interpreted as a palimpsest resulting from alternating occupation of the cave by human groups and carnivores. The distribution study shows that faunal specimens, lithic artefacts, hearths and charcoal fragments are significantly concentrated at the entrance of the cave where, it is inferred, hominins carried out different activities, while carnivores preferred the sheltered zones in the inner areas of the cave. The results obtained reveal a spatial pattern characterized by fire use related zones, and show that the site was occupied by Neanderthals in a similar and consistent way throughout the ˃ 7000 years range covered by the analysed subunits. This spatial pattern is interpreted as resulting from repeated short-term human occupations.

The bears from Dmanisi and the first dispersal of early Homo out of Africa.

We report on the taxonomy and paleodiet of the bear population that inhabited the emblematic palaeoanthropological Early Pleistocene (1.8 Ma) site of Dmanisi (Georgia), based on a dual approach combining morphometrics and microwear of upper and lower teeth. Given that the teeth of Ursus etruscus Cuvier, 1823 from Dmanisi show considerable size variability, their systematic position has been debated. However, a comparative study of the coefficients of variation for tooth size measurements in several modern bear species shows that the variability in tooth size of the ursid population from Dmanisi could result from sexual dimorphism. The analysis of tooth microwear indicates that these bears inhabited a mixed environment of open plain with forest patches, where they had a browsing diet with a substantial contribution of meat and/or fish. Comparative tooth morphometric analyses of modern ursids and fossil U. etruscus indicate that this extinct species had an omnivorous behavior similar to that of extant brown bears. The ecological interactions of the Dmanisi bears with other members of the large mammals community, including the first hominins that dispersed out of Africa, are discussed in the light of this new evidence.

Combined dental wear and cementum analyses in ungulates reveal the seasonality of Neanderthal occupations in Covalejos Cave (Northern Iberia).

We propose for the first time the use of the combination of two high-resolution techniques, dental wear (meso- and microwear) and dental cementum analyses, to gain a better understanding of Neanderthal subsistence strategies and occupational patterns. Dental wear analysis provides information not only on ungulate palaeodiet and palaeoenvironments but also on hunting time and seasons. Dental cementum analysis allows the accurate determination of the age and season at death of a prey. Our study has focused on the Cantabrian region and has applied both methods to investigate the Mousterian faunal assemblages in Covalejos Cave. Identification of the ungulate palaeodiet reveals information on the environmental conditions of the studied region. Moreover, it may facilitate observation on the evolution of both palaeodiet and palaeoenvironment throughout the site sequence. Results show a general stability in the palaeoenvironmental conditions and in the ungulate palaeodiet throughout the Mousterian sequence; this finding may be attributed to the role of the area as a climate refuge, and slight differences in levels 8, 7 and 4 suggest long- or short-term but repeated Neanderthal occupations at different seasons in the annual cycle.

Microwear and isotopic analyses on cave bear remains from Toll Cave reveal both short-term and long-term dietary habits.

Dietary habits of the extinct Ursus spelaeus have always been a controversial topic in paleontological studies. In this work, we investigate carbon and nitrogen values in the bone collagen and dental microwear of U. spelaeus specimens recovered in Level 4 from Toll Cave (Moià, Catalonia, NE Iberian Peninsula). These remains have been dated to > 49,000 14C BP. The ability of both proxies to provide data on the diet of U. spelaeus at different times in the life-history (isotopes: average diet of life; microwear: last days/weeks before death), allows us to generate high-resolution and complementary data. Our results show lower values (δ13C & δ15N) in cave bears than in strict herbivores (i.e. Cervus elaphus) recovered from the same level of Toll Cave. On the other hand, 12 lower molars (m1) were analysed through low-magnification microwear technique. The cave bears from Toll Cave show a microwear pattern like that of extant bears with omnivorous and carnivorous diets. These data are discussed in the framework of all available data in Europe and add new information about the plasticity of the dietary habits of this species at the southern latitudes of Europe during Late Pleistocene periods.

Multiproxy evidence for leaf-browsing and closed habitats in extinct proboscideans (Mammalia, Proboscidea) from Central Chile.

Proboscideans are so-called ecosystem engineers and are considered key players in hypotheses about Late Pleistocene megafaunal extinctions. However, knowledge about the autoecology and chronology of the proboscideans in South America is still open to debate and raises controversial views. Here, we used a range of multiproxy approaches and new radiocarbon datings to study the autoecology of Chilean gomphotheres, the only group of proboscideans to reach South America during the Great American Biotic Interchange (∼3.1 to 2.7 million years before present). As part of this study, we analyzed stable isotopes, dental microwear, and dental calculus microfossils on gomphothere molars from 30 Late Pleistocene sites (31° to 42°S). These proxies provided different scales of temporal resolution, which were then combined to assess the dietary and habitat patterns of these proboscideans. The multiproxy study suggests that most foraging took place in relatively closed environments. In Central Chile, there is a positive correlation between lower δ13C values and an increasing consumption of arboreal/scrub elements. Analyses of dental microwear and calculus microfossils have verified these leaf-browsing feeding habits. From a comparative perspective, the dietary pattern of South American gomphotheres appears to be constrained more by resource availability than by the potential dietary range of the individual taxa. This multiproxy study is aimed at increasing knowledge of the life history of gomphotheres and thus follows an issue considered one of the greatest challenges for paleontology in South America, recently pointed out by the need to thoroughly understand the role of ecological engineers before making predictions about the consequences of ecosystem defaunation.

Large mammal diets and paleoecology across the Oldowan-Acheulean transition at Olduvai Gorge, Tanzania from stable isotope and tooth wear analyses.

The well-dated Pleistocene sediments at Olduvai Gorge have yielded a rich record of hominin fossils, stone tools, and vertebrate faunal remains that, taken together, provide insight to hominin behavior and paleoecology. Since 2008, the Olduvai Geochronology and Archaeology Project (OGAP) has undertaken extensive excavations in Bed II that have yielded a large collection of early Pleistocene stone tools and fossils. The strata of Lower, Middle and Upper Bed II at Olduvai Gorge capture the critical transition from Oldowan to Acheulean technology and therefore provide an opportunity to explore the possible role of biotic and abiotic change during the transition. Here, we analyze newly discovered and existing fossil teeth from Bed II sites using stable isotope and tooth wear methods to investigate the diets of large mammals. We reconstruct the dietary ecology of Bed II mammals and evaluate whether vegetation or hydroclimate shifts are associated with the technological change. Combined isotope and tooth wear data suggest most mammals were C4 grazers or mixed feeders. Carbon isotope data from bulk enamel samples indicate that a large majority of Bed II large mammals analyzed had diets comprising mostly C4 vegetation (>75% of diet), whereas only a small number of individuals had either mixed C3-C4 or mostly C3 diets (<25% C4). Mesowear generally indicates an increase of the abrasiveness of the diet between intervals IIA and IIB (∼1.66 Ma), probably reflecting increased grazing. Microwear indicates more abrasive diets in interval IIA suggesting stronger seasonal differences at the time of death during this interval. This is also supported by the intratooth isotope profiles from Equus oldowayensis molars, which suggest a possible decrease in seasonality across the transition. Neither stable isotope nor tooth wear analyses indicate major vegetation or hydrological change across the Oldowan-Acheulean transition.

Dietary traits of the ungulates from the HWK EE site at Olduvai Gorge (Tanzania): Diachronic changes and seasonality.

The Oldowan site HWK EE (Olduvai Gorge, Tanzania) has yielded a large fossil and stone tool assemblage at the transition from Lower to Middle Bed II, ∼1.7 Ma. Integrated tooth wear and stable isotope analyses were performed on the three most abundant ungulate taxa from HWK EE, namely Alcelaphini, cf. Antidorcas recki (Antilopini) and Equus oldowayensis (Equini), to infer dietary traits in each taxon. Some paleodietary changes were observed for cf. A. recki and E. oldowayensis based on tooth wear at the transition from the Lemuta to the Lower Augitic Sandstone (LAS) interval within the HWK EE sequence. Stable carbon and oxygen isotope data show no significant changes in bulk diet or hydroclimate between the Lemuta and LAS intervals. The combined tooth wear and stable isotope data suggest similar paleoecological conditions across the two HWK EE intervals, but that differences in vegetation consumed among ungulates may have resulted in changes in dietary niches. Integrating tooth wear and stable isotope analyses permits the characterization of ungulate diets and habitats at HWK EE where C4 dominated and minor mixed C3 and C4 habitats were present. Our results provide a better understanding of the paleoenvironmental conditions of the Lemuta and LAS intervals. The LAS assemblage was mostly accumulated during relatively dry periods at Olduvai Gorge when grasses were not as readily available and grazing animals may have been more nutritionally-stressed than during the formation of the Lemuta assemblage. This helps to contextualize variations in hominin and carnivore feeding behavior observed from the faunal assemblages produced during the two main occupations of the site.

Make it clear: molds, transparent casts and lightning techniques for stereomicroscopic analysis of taphonomic modifications on bone surfaces.

This paper provides detailed description of a non-destructive, low-cost, and low-time consuming technique for producing high-resolution casts for the observation of taphonomic modifications on bone surfaces. The aim of the whole process is to obtain molds that accurately replicate the original bone surface at both the macro- and microscopic levels. The high quality transparent epoxy casts produced are analyzed by light microscopy and used to produce detailed microphotographs of bone surfaces. After describing each step of the process, we present some examples of its application in the case of anthropic activity, carnivores, or other post-depositional modifications.

A tool for determining duration of mortality events in archaeological assemblages using extant ungulate microwear.

The seasonality of human occupations in archaeological sites is highly significant for the study of hominin behavioural ecology, in particular the hunting strategies for their main prey-ungulates. We propose a new tool to quantify such seasonality from tooth microwear patterns in a dataset of ten large samples of extant ungulates resulting from well-known mass mortality events. The tool is based on the combination of two measures of variability of scratch density, namely standard deviation and coefficient of variation. The integration of these two measurements of variability permits the classification of each case into one of the following three categories: (1) short events, (2) long-continued event and (3) two separated short events. The tool is tested on a selection of eleven fossil samples from five Palaeolithic localities in Western Europe which show a consistent classification in the three categories. The tool proposed here opens new doors to investigate seasonal patterns of ungulate accumulations in archaeological sites using non-destructive sampling.

A new approach for deciphering between single and multiple accumulation events using intra-tooth isotopic variations: Application to the Middle Pleistocene bone bed of Schöningen 13 II-4.

It is often difficult to differentiate between archaeological bonebeds formed by one event such as a mass kill of a single herd, and those formed by multiple events that occurred over a longer period of time. The application of high temporal resolution studies such as intra-tooth isotopic profiles on archaeological mammal cohorts offers new possibilities for exploring this issue, allowing investigators to decipher between single and multiple accumulation events. We examined (18)O and (13)C isotopic variations from the enamel carbonate of 23 horse third molars from the Middle Pleistocene archaeological site of Schöningen. We employed a new approach to investigate processes of fossil accumulation that uses both bulk and intra-tooth isotopic variations and takes into account animal behavior, age at death and dental development to test the degree of isotopic affinity of animals from the same fossil assemblage. Oxygen and carbon isotope bulk values indicate that the horses from Schöningen 13 II-4 experienced relatively similar climatic and dietary regimes. Inter-individual differences of the bulk values of the horses sampled in the current study present nevertheless inter-individual variability similar to individuals from multi-layered localities. In addition, the intra-tooth isotopic variation of specimens of the same age at death seems to indicate that the studied cohort corresponds to a mix of individuals that recorded both similar and different isotopic histories. Finally, the conditions recorded in the isotopic signal shortly before death (i.e., for teeth not fully mineralized) varied between sampled individuals, suggesting possible differences in the seasonality of death. Considering those results, we discuss the possibility that the horses from Schöningen 13 II-4 correspond to an accumulation of different death events.

Investigation of equid paleodiet from Schöningen 13 II-4 through dental wear and isotopic analyses: Archaeological implications.

The paleodietary traits of the equid population from Schöningen 13 II-4 were investigated through tooth mesowear and microwear analyses, as well as stable isotopic analyses. The mesowear pattern observed on the upper teeth indicates a low abrasion diet with a significant amount of browse in the diet of the horses. The tooth microwear analysis and the isotopic data confirm that the horses from Schöningen 13 II-4 were mixed feeders, like many populations from other Pleistocene localities in Northern and Eastern Europe. Microwear also provides information on seasonal changes in the diet of the horses and offers the possibility to test hypotheses about the presence of one or several horse populations. Our analysis determined that the assemblage of horse remains from Schöningen 13 II-4 resulted from multiple accumulation events, which took place at different periods of time.

Middle Pleistocene ecology and Neanderthal subsistence: insights from stable isotope analyses in Payre (Ardèche, southeastern France).

The Middle Palaeolithic site of Payre in southeastern France yields abundant archaeological material associated with fossil hominid remains. With its long sequence of Middle Pleistocene deposits, Payre is a key site to study the Middle Palaeolithic chronology of this region. This study is the first to investigate carbon and oxygen isotope contents of Neanderthal tooth enamel bioapatite, together with a wide range of herbivorous and carnivorous species. The aim is to contribute to the understanding of hunting behaviour, resource partitioning, diet and habitat use of animals and Neanderthals through a palaeoecological reconstruction. Local topography had a visible influence on carbon and oxygen stable isotope values recorded in herbivore tooth enamel. This was used to investigate possible habitats of herbivores. The different herbivorous species do not show large variations of their carbon and oxygen isotope values through time, indicating niche conservatism from OIS 8-7 to OIS 6-5, i.e., independently of palaeoclimatic and palaeoenvironmental variations. Based on these new observations, we conclude that Neanderthals employed a stable subsistence strategy over time, using a variety of local resources, with resource partitioning visible between humans and carnivores, especially wolves. A comparison of the results of stable isotopic investigation with the results of tooth wear analyses previously conducted on the same teeth allowed us to demonstrate that grazing and browsing do not bind animals to a specific habitat in a C3 environment as reflected in the isotopic values.

Dietary change and evolution of horses in North America.

The evolution of high-crowned molars among horses (Family Equidae) is thought to be an adaptation for abrasive diets associated with the spread of grasslands. The sharpness and relief of the worn cusp apices of teeth (mesowear) are a measure of dietary abrasion. We collected mesowear data for North American Equidae for the past 55.5 million years to test the association of molar height and dietary abrasion. Mesowear trends in horses are reflective of global cooling and associated vegetation changes. There is a strong correlation between mesowear and crown height in horses; however, most horse paleopopulations had highly variable amounts of dietary abrasion, suggesting that selective pressures for crown height may have been weak much of the time. However, instances of higher abrasion were observed in some paleopopulations, suggesting intervals of stronger selection for the evolution of dentitions, including the early Miocene shortly before the first appearance of Equinae, the horse subfamily in which high-crowned dentitions evolved.

A new application of dental wear analyses: estimation of duration of hominid occupations in archaeological localities.

Characterization of settlement patterns is one of the core concepts in archeological research. The duration of an occupation is usually estimated through zooarchaeology (e.g., density of remains, cementochronology) and is limited by taphonomic processes and sample size. We propose a new application of dental wear methods for estimating the relative duration of hominid settlements in Paleolithic sites. Dental microwear is known to be sensitive to seasonal changes in diet. In this new application we use microwear scratch counts to estimate the variation in the dietary signal of various ungulate species. We propose that this variation is correlated to the duration of site occupation. Each season presents a limited and different set of food resources available in the environment. If animals are sampled only during a specific season (i.e., during a short term occupation) then they would be expected to have a dental wear signal with little variation. On the other hand, a greater diversity of food is available across different seasons. Therefore, if game animals are hunted through various seasons during long occupation periods, then they would be expected to have more variable dental wear. The application of this technique to the Middle Paleolithic site of Arago Cave (France), where various types of occupations occurred, supports this hypothesis. When combined with multidisciplinary studies of archaeological localities (seasonality in particular), this new application of dental wear analysis presents valuable information about hominid settlements and behavior. We contextualize our data with results from lithic and zooarchaeological analyses from Arago. These results reveal the presence of both high and low mobility groups of Homo heidelbergensis throughout the sequence of the Arago Cave.