Hand to mouth in a Neandertal : right-handedness in regourdou 1

We describe and analyze a Neandertal postcranial skeleton and dentition, which together show unambiguous signs of right-handedness. Asymmetries between the left and right upper arm in Regourdou 1 were identified nearly 20 years ago, then confirmed by more detailed analyses of the inner bone structure for the clavicle, humerus, radius and ulna. The total pattern of all bones in the shoulder and arm reveals that Regourdou 1 was a right-hander. Confirmatory evidence comes from the mandibular incisors, which display a distinct pattern of right oblique scratches, typical of right-handed manipulations performed at the front of the mouth. Regourdou's right handedness is consistent with the strong pattern of manual lateralization in Neandertals and further confirms a modern pattern of left brain dominance, presumably signally linguistic competence. These observations along with cultural, genetic and morphological evidence indicate language competence in Neandertals and their European precursors

Hand to Mouth in a Neandertal: Right-Handedness in Regourdou 1

We describe and analyze a Neandertal postcranial skeleton and dentition, which together show unambiguous signs of right-handedness. Asymmetries between the left and right upper arm in Regourdou 1 were identified nearly 20 years ago, then confirmed by more detailed analyses of the inner bone structure for the clavicle, humerus, radius and ulna. The total pattern of all bones in the shoulder and arm reveals that Regourdou 1 was a right-hander. Confirmatory evidence comes from the mandibular incisors, which display a distinct pattern of right oblique scratches, typical of right-handed manipulations performed at the front of the mouth. Regourdou's right handedness is consistent with the strong pattern of manual lateralization in Neandertals and further confirms a modern pattern of left brain dominance, presumably signally linguistic competence. These observations along with cultural, genetic and morphological evidence indicate language competence in Neandertals and their European precursors.The TNT European project, French CNRS, Région Poitou-Charentes, Nespos Society, and Leakey Foundation provided financial support

Digital reconstruction of the inner ear of Leptictidium auderiense (Leptictida, Mammalia) and North American leptictids reveals new insight into leptictidan locomotor agility

Leptictida are basal Paleocene to Oligocene eutherians from Europe and North America comprising species with highly specialized postcranial features including elongated hind limbs. Among them, the European Leptictidium was probably a bipedal runner or jumper. Because the semicircular canals of the inner ear are involved in detecting angular acceleration of the head, their morphometry can be used as a proxy to elucidate the agility in fossil mammals. Here we provide the first insight into inner ear anatomy and morphometry of Leptictida based on high-resolution computed tomography of a new specimen of Leptictidium auderiense from the middle Eocene Messel Pit (Germany) and specimens of the North American Leptictis and Palaeictops. The general morphology of the bony labyrinth reveals several plesiomorphic mammalian features, such as a secondary crus commune. Leptictidium is derived from the leptictidan groundplan in lacking the secondary bony lamina and having proportionally larger semicircular canals than the leptictids under study. Our estimations reveal that Leptictidium was a very agile animal with agility score values (4.6 and 5.5, respectively) comparable to Macroscelidea and extant bipedal saltatory placentals. Leptictis and Palaeictops have lower agility scores (3.4 to 4.1), which correspond to the more generalized types of locomotion (e.g., terrestrial, cursorial) of most extant mammals. In contrast, the angular velocity magnitude predicted from semicircular canal angles supports a conflicting pattern of agility among leptictidans, but the significance of these differences might be challenged when more is known about intraspecific variation and the pattern of semicircular canal angles in non-primate mammals

Morphogenèse de l’endostructure osseuse de l’ilion humain

L’acquisition progressive pendant le stade infantile humain de la posture orthograde et de la locomotion bipède est responsable d’importants changements morphostructuraux de l’os au niveau du bassin et de l’articulation coxofémorale. Cette étude utilise des techniques d’analyse numérique d’images radiographiques et de relevés microtomographiques à haute résolution pour caractériser les propriétés texturales du réseau trabéculaire et les variations topographiques de l’enveloppe corticale dans une série ontogénétique de 15 ilions d’individus âgés entre 0 et 40 ans. Les résultats suggèrent que les principales structures de l’architecture trabéculaire fonctionnelles à la distribution et dissipation des charges posturales et locomotrices sont déjà reconnaissables à partir de la tranche d’âge d’un à deux ans, en association avec l’initiation d’une marche bipède non assistée.Through the human infantile stage, the progressive acquisition of the orthograde posture and bipedal locomotion is responsible for important morphostructural bony changes at the pelvis and the coxofemoral joint. This study uses digital processing techniques applied to a set of radiographic and microtomographic images to characterise the textural properties of the trabecular network and the topographic variation of the cortical shell in an ontogenetic series of 15 ilia from individuals aged between 0 and 40 years. The results suggest that the main structures of the trabecular architecture which are functional to the distribution and dissipation of the postural- and locomotor-related loads, are already recognizable at the age of 1–2 years, in association with the adoption of bipedal walking.</p

Morphogenèse des propriétés texturales du tissu osseux et environnement biomécanique (caractérisation non invasive du réseau trabéculaire et de l'os cortical du squelette appendiculaire de mammifères actuels et fossiles, hominidés inclus)

La compréhension de l'influence relative des facteurs génétiques et environnementaux/biomécaniques dans la morphogenèse et l adaptation structurale des tissus osseux cortical et trabéculaire est critique dans l étude de l'évolution morpho-fonctionnelle du squelette postcrânien. Cependant, les relations dynamiques entre mise en place des patrons de charges et caractérisation texturale sito-spécifique du réseau trabéculaire et de l enveloppe corticale restent à préciser dans une perspective quantitative. Ce travail de recherche, à forte composante méthodologique, a eu pour objectifs i) la modélisation qualitative et quantitative de la morphogenèse des propriétés texturales de l'ilion humain; ii) la compréhension des relations intimes entre enveloppe corticale le "contenant" - et architecture structurale le "contenu"; iii) l'extraction - de nature non invasive et à haute résolution - et l'interprétation biomécanique de la signature endo-structurale de différents éléments du squelette appendiculaire de Mammifères, actuels et fossiles. Basée sur un large échantillon d'images numériques de référence 2-3D, l'application de notre protocole analytique à des spécimens fossiles sélectionnés, représentant taxons très variés du point de vue de la taille et du style de vie-contraintes environnementales-comportement locomoteur et issus de contextes géo-chronologiques différenciés, confirme la potentialité informative de ce genre d'approche dans une perspective paléobiomécanique.The understanding of the relative influence of the genetic and environmental/biomechanical factors involved in the morphogenesis and structural adaptation of the cortical and trabecular bone is critical for the study of the morpho-functional evolution of the postcranial skeleton. Nonetheless, the dynamic relationships between load models and site-specific textural characterization of the trabecular network and cortical shell are still poorly known in a quantitative perspective. The goals of the present research, of special methodological value, were i) the qualitative and quantitative modelling of the morphogenetic patterns of the human iliac bone textural properties; ii) the understanding of the intimate relationships between cortical shell the "container" and structural architecture the "content"; iii) the nonivasive, high resolution extraction and biomechanical interpretation of the endostructural signature recorded at various sites of the appendicular skeleton in extant and fossil Mammalian taxa. Based on a representative comparative sample of 2-3D numerical images, the application of our analytical protocol to a number of fossil specimens representing highly differenciated taxa in terms of body mass and life style-environmental constraints-locomotor behaviour, selected from a variety of geo-chronological contexts, confirms the potential informative value of such investigative approach in a paleobiomechanical perspective.POITIERS-BU Sciences (861942102) / SudocSudocFranceF

A Neanderthal partial femoral diaphysis from the "grotte de la Tour", La Chaise-de-Vouthon (Charente, France): Outer morphology and endostructural organization

Article sous presseWe describe a human partial femoral shaft discovered during speleological exploration of the "grotte de la Tour", near the prehistoric site of La Chaise-de-Vouthon (Charente, France). The context of discovery is compatible with a hyena den deposit; the associated mammal assemblage suggests a preliminary chronological attribution to MIS 3. Combined information from its outer morphology, cross-sectional geometric properties, and from the high-resolution 3D imaging and quantitative analysis of its inner structural organization shows that this specimen (CDV-Tour 1) is from an adult Neanderthal individual, more likely a male

Three-dimensional imaging and quantitative characterization of human fossil remains. Examples from the NESPOS database

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From Financial Depression to Financial Deregulation? The Construction of Futures Trading Industry in Taiwan

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Morphometric maps of long bone shafts and dental roots for imaging topographic thickness variation

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