Frédéric Santos

The Reality of Neandertal Symbolic Behavior at the Grotte du Renne, Arcy-sur-Cure, France

Background The question of whether symbolically mediated behavior is exclusive to modern humans or shared with anatomically archaic populations such as the Neandertals is hotly debated. At the Grotte du Renne, Arcy-sur-Cure, France, the Châtelperronian levels contain Neandertal remains and large numbers of personal ornaments, decorated bone tools and colorants, but it has been suggested that this association reflects intrusion of the symbolic artifacts from the overlying Protoaurignacian and/or of the Neandertal remains from the underlying Mousterian. Methodology/Principal Findings We tested these hypotheses against the horizontal and vertical distributions of the various categories of diagnostic finds and statistically assessed the probability that the Châtelperronian levels are of mixed composition. Our results reject that the associations result from large or small scale, localized or generalized post-depositional displacement, and they imply that incomplete sample decontamination is the parsimonious explanation for the stratigraphic anomalies seen in the radiocarbon dating of the sequence. Conclusions/Significance The symbolic artifacts in the Châtelperronian of the Grotte du Renne are indeed Neandertal material culture.

Facial soft tissue depths in French adults: Variability, specificity and estimation

Facial soft tissue depths (FSTD) are used in facial approximation to render the shape of the face, and are traditionally published specifically to population, corpulence, and sex amongst other factors. This paper investigates the variability of FSTD collected at 37 landmarks on 500 CT (computed tomography) scans of French living individuals. The specificity of the sample is evaluated by comparing values with six published datasets of various populations and recording techniques. Apart from a significant influence of the corpulence, FSTD show negligible variations with age and sex. The differences between the French sample and other datasets contradict the hypothesis of major influence of population, and underline sample specificity linked with technique and methodology of data measurement. Regression equations were computed to estimate FSTD using age, sex, facial build, and craniometrics, leading to more accurate results if such factors are known. Nevertheless, application of the pooled T-table (Tallied-Facial-Soft-Tissue-Depth-Data) has been validated according to the French sample.

Three-dimensional computer-assisted craniometrics: A comparison of the uncertainty in measurement induced by surface reconstruction performed by two computer programs

Digital investigation of anthropological material through computed tomography (CT) offers several new opportunities in morphometrics. However, an object measured with computer-assisted methods does not necessarily exactly match the original one. The scanning and surface reconstruction of the object induce some alterations, and data acquisition is prone to measurement uncertainty. The purpose of this research is to evaluate the intra- and inter-observers variations in medical CT scan measurements of a known-size phantom and two dry crania. Two software packages, AMIRA and Treatment and Increased Vision for Medical Imaging (TIVMI), which use different techniques of surface reconstructions, were compared. The mean difference between the measurements was lower for TIVMI, using an objective algorithm based on the half-maximum height (HMH) protocol in three dimensions (3D). AMIRA can induce up to a 4% error in known measurements and 5% uncertainty in dry skull measurements. This study emphasises the risk of object shape alteration in each step of its digitisation.

Anthropological facial approximation in three dimensions (AFA3D): Computer-assisted estimation of the facial morphology using geometric morphometrics

This study presents Anthropological Facial Approximation in Three Dimensions (AFA3D), a new computerized method for estimating face shape based on computed tomography (CT) scans of 500 French individuals. Facial soft tissue depths are estimated based on age, sex, corpulence, and craniometrics, and projected using reference planes to obtain the global facial appearance. Position and shape of the eyes, nose, mouth, and ears are inferred from cranial landmarks through geometric morphometrics. The 100 estimated cutaneous landmarks are then used to warp a generic face to the target facial approximation. A validation by re‐sampling on a subsample demonstrated an average accuracy of c. 4 mm for the overall face. The resulting approximation is an objective probable facial shape, but is also synthetic (i.e., without texture), and therefore needs to be enhanced artistically prior to its use in forensic cases. AFA3D, integrated in the TIVMI software, is available freely for further testing.

Life history of the individuals buried in the St. Benedict Cemetery (Prague, 15th–18th Centuries): Insights from 14C dating and stable isotope (δ13C, δ15N, δ18O) analysis

Funerary practices and bioarchaeological (sex and age) data suggest that a mortality crisis linked to an epidemic episode occurred during the fifth phase of the St. Benedict cemetery in Prague (Czech Republic). To identify this mass mortality episode, we reconstructed individual life histories (dietary and mobility factors), assessed the populations biological homogeneity, and proposed a new chronology through stable isotope analysis (δ(13)C, δ(18)O and δ(15)N) and direct radiocarbon dating. Stable isotope analysis was conducted on the bone and tooth enamel (collagen and carbonate) of 19 individuals from three multiple graves (MG) and 12 individuals from individual graves (IG). The δ(15)N values of collagen and the difference between the δ(13)C values of collagen and bone carbonate could indicate that the IG individuals had a richer protein diet than the MG individuals or different food resources. The human bone and enamel carbonate and δ(18)O values suggest that the majority of individuals from MG and all individuals from IG spent most of their lives outside of the Bohemian region. Variations in δ(18)O values also indicate that all individuals experienced residential mobility during their lives. The stable isotope results, biological (age and sex) data and eight (14)C dates clearly differentiate the MG and IG groups. The present work provides evidence for the reuse of the St. Benedict cemetery to bury soldiers despite the funeral protest ban (1635 AD). The Siege of Prague (1742 AD) by French-Bavarian-Saxon armies is identified as the cause of the St. Benedict mass mortality event.

Des nouveaux vestiges néanderthaliens à Las Pélénos (Monsempron-Libos, Lot-et-Garonne, France)

RésuméLe site de Las Pélénos (Monsempron-Libos, Lotet-Garonne) a été fouillé en 1950 par L. Coulonges puis à plusieurs reprises entre 1974 et 2008 par l’un d’entre nous (A.Q.), parallèlement à des travaux d’entretien. Dix vestiges néanderthaliens ont été découverts dans le niveau moustérien lors des fouilles de L. Coulonges. Depuis 1995, 4 autres vestiges humains ont été mis au jour, pour partie hors contexte stratigraphique : deux dents et deux éléments de voûte crânienne. Ils sont supposés provenir également du niveau moustérien reconnu lors des fouilles de L. Coulonges et la question de leur identité phylogénétique est posée. Ces pièces ont donc fait l’objet d’une étude morpho-métrique afin de fournir une réponse. L’analyse des traits morphologiques observés sur ces quatre pièces ne laisse pas de doute quant à leur appartenance aux Néanderthaliens. Les données métriques, sans être spécifiques, s’intègrent dans la variabilité connue de la population.AbstractThe Las Pélénos site was excavated in 1950 by L. Coulonges, then several times between 1974 and 2008 by one of our team (A.Q.). During Coulonges’ excavations, ten Neanderthal remains were discovered in the Mousterian layer. Since 1995, four other human remains have been unearthed, partly outside their stratigraphic context. These remains include two teeth and two cranial vault pieces. They are thought to come from the Mousterian context found during the Coulonges dig, but their phylogenetic identity has yet to be confirmed. A comparative morphometric study was therefore made. Our analysis of a number of their morphological traits indicates that the specimens are undoubtedly Neanderthal remains. The metric data, although nonspecific, are within the known range of variability of the Neanderthal population.

Validation and reliability of the sex estimation of the human os coxae using freely available DSP2 software for bioarchaeology and forensic anthropology

OBJECTIVES A new tool for skeletal sex estimation based on measurements of the human os coxae is presented using skeletons from a metapopulation of identified adult individuals from twelve independent population samples. For reliable sex estimation, a posterior probability greater than 0.95 was considered to be the classification threshold: below this value, estimates are considered indeterminate. By providing free software, we aim to develop an even more disseminated method for sex estimation. MATERIALS AND METHODS Ten metric variables collected from 2,040 ossa coxa of adult subjects of known sex were recorded between 1986 and 2002 (reference sample). To test both the validity and reliability, a target sample consisting of two series of adult ossa coxa of known sex (n = 623) was used. The DSP2 software (Diagnose Sexuelle Probabiliste v2) is based on Linear Discriminant Analysis, and the posterior probabilities are calculated using an R script. RESULTS For the reference sample, any combination of four dimensions provides a correct sex estimate in at least 99% of cases. The percentage of individuals for whom sex can be estimated depends on the number of dimensions; for all ten variables it is higher than 90%. Those results are confirmed in the target sample. DISCUSSION Our posterior probability threshold of 0.95 for sex estimate corresponds to the traditional sectioning point used in osteological studies. DSP2 software is replacing the former version that should not be used anymore. DSP2 is a robust and reliable technique for sexing adult os coxae, and is also user friendly.

Using classifications to identify pathological and taphonomic modifications on ancient bones: Do “taphognomonic” criteria exist?

Pathological and taphonomic agents can sometimes produce bone modifications that seem indistinguishable from one another, even to an experienced eye. The aim of this study is to propose a classification system to identify modifications observed on skeletal elements from different environmental and chronological contexts, with similar morphologies but varied aetiologies. Two types of classifications, empirical and statistical, were constructed, tested by two independent observers and compared. This classification system aims to categorise, differentiate and identify pathological and taphonomic bone modifications. In this paper, we identify several taphonomic criteria and propose a new term, “taphognomonic”, to characterise criteria that are specific to particular taphonomic agents. The two classification methods complement each other by providing precise (empirical classification) and reliable (statistical classification) diagnostic criteria. Finally, criteria are highlighted to differentiate pseudo-pathological from pathological bone modifications, the ultimate goal being to reduce the risk of misdiagnosis.RésuméCertains agents pathologiques ou taphonomiques peuvent être à l’origine de modifications osseuses tellement similaires que même un observateur aguerri ne peut les distinguer. Le but de cette étude est de proposer un outil d’identification d’un ensemble de modifications osseuses de morphologies similaires mais d’étiologies différentes, observées sur des éléments provenant d’environnements et de périodes différents. Deux systèmes de classification, empirique et statistique, ont été construits, puis testés et comparés par deux observateurs indépendants. Ces systèmes classent, différencient et identifient desmodifications osseuses d’origine taphonomique ou pathologique. Cette étude a permis d’identifier plusieurs critères taphonomiques et de proposer un nouveau terme, « taphognomonique », pour caractériser des critères spécifiques à certains agents taphonomiques. Les deux types de classification sont complémentaires: ils apportent des critères diagnostiques à la fois précis (classification empirique) et fiables (classification statistique). Enfin, les critères permettant de différencier les modifications pseudopathologiques des modifications d’origine pathologique sont mis en avant, le but ultime étant de réduire le risque d’erreur diagnostique.

In situ study of the Gravettian individual from Cussac cave, locus 2 (Dordogne, France)

OBJECTIVES Cussac cave, discovered in 2000, is characterized by the exceptional presence of monumental engravings and human remains deposited in bear nests. Both the style of the art and a direct radiocarbon date indicate a Gravettian age. As the cave is protected as a national heritage site, only very limited access to and restricted direct interventions involving the human remains are possible. Here, we present the results of observations and measurements of Cussac L2A, represented by a virtually complete skeleton covered with a layer of clay. MATERIALS AND METHODS A portion of the clay that covered some bones was removed in order to undertake a study of the skeleton in situ. The age-at-death was assessed using several indicators, especially changes on the auricular surface of the ilium. The sex was assessed using the morphology and morphometrics of the coxal bones. Cussac L2A stature, humero-femoral index, and crural index were also estimated. The dimensions of the Cussac L2A skeletal remains are compared with the other European Gravettian and Late Upper Paleolithic human remains using adjusted Z-Scores. RESULTS The analysis indicates that Cussac L2A is probably a male who died aged between 20 and 50 years. If the sex assessment is correct, with an averaged estimated stature of 1.64 m, Cussac L2A would be one of the shorter Gravettian males. DISCUSSION These results raise the importance of the new discoveries to better understand the variability of Upper Paleolithic skeletal morphology and stress the difficulties in marrying heritage preservation and scientific investigations.

The new Coimbra method for recording entheseal changes and the effect of age-at-death

Entheseal changes have been widely used in anthropology to study activity patterns, but there is an increasing awareness that ageing is associated with these changes. The aim of this study was to test each feature of the new Coimbra method for its variability, side asymmetry and its relationship with age. In addition to this, an overall relationship with age was tested for a larger sample. Males 16 and over from the Coimbra skeletal collection of historically identified individuals were recorded using the new method (N = 260). To reduce the impact of occupation, side variability in asymmetry and age were only tested in the labourers (N = 51). All occupation groups were included to test the overall relationship with age using a random forest test. The results show that scores lack variability for many of the features and entheses. Where there is side asymmetry this is typically in favour of higher scores in the right side, excepting the biceps brachii insertion. Most of the features scored show a relationship with ageing, but this is not uniform for all features or entheses. Some features are associated with an increase in age (bone formation and erosions), while others generally occur in younger individuals (fine porosity and textural change). Logistic regression showed that ageing explains at most 44% of the variability. This alongside the side asymmetry may indicate that biomechanics has an explanatory role.RésuméLes changements au niveau des enthèses ont été largement utilisés en anthropologie biologique pour discuter des patterns d’activités, malgré les études de plus en plus fréquentes associant ces changements principalement au vieillissement. L’objectif de cette étude est d’illustrer, pour chacune des modifications enregistrées avec la nouvelle méthode de Coimbra, la distribution générale des scores, l’asymétrie et leur relation à l’âge. Une étude plus globale sur l’effet du vieillissement a également été menée. L’analyse porte sur un échantillon de squelettes de sujets masculins décédés à 16 ans ou plus issus de la collection de squelettes identifiés de Coimbra (n = 260). Pour réduire l’influence de l’activité physique, seuls les sujets avec la profession de « trabalhador » (travailleur) ont été utilisés dans les tests sur l’asymétrie et l’âge (n = 51). Pour l’étude globale sur l’effet du vieillissement, toutes les professions ont été incluses dans une analyse utilisant les forêts aléatoires. Les résultats montrent que la variabilité des scores est faible pour la plupart des changements et des enthèses. Il existe une asymétrie assez claire avec des scores plus élevés du côté droit, sauf pour l’insertion du biceps brachii. La plupart des changements enregistrés présentent une corrélation positive avec l’âge au décès, sans toutefois être systématiques pour tous les changements ou toutes les enthèses considérées. Certains changements sont plus fréquents chez les sujets âgés (formation osseuse, érosion), alors que d’autres se retrouvent plus souvent chez les jeunes sujets (porosité fine et changement mineur de surface). Une régression logistique montre que le vieillissement explique au mieux 44 % de la variabilité perçue. Cela, ainsi que l’asymétrie directionnelle observée, pourrait indiquer que les phénomènes biomécaniques jouent un rôle dans l’apparition de ces changements.