Christine Couture-Veschambre

The vertebral column of the Regourdou 1 Neandertal.

The Regourdou 1 partial skeleton was found in 1957 in level IV of the eponymous site located in Montignac-sur-Vézère (Dordogne, France) and until now it has been only partially published. The ongoing revision of the faunal remains from the site has yielded additional fossils that pertain to this skeleton. Here we study the vertebral column of this individual, providing for the first time detailed descriptions for all of the fossils and reassessing the anatomical position of all of the fragments. The vertebral column of Regourdou 1 is one of the most complete in the Neandertal fossil record with at least 20 pre-sacral vertebrae (seven cervicals, nine thoracic and four lumbars), a partial sacrum and a fragmentary first coccygeal vertebra. When compared with modern humans, the vertebrae of Regourdou 1 display significant metric differences, and fit well within the range of Neandertal variability. A preliminary analysis of the most complete thoracic vertebrae of this individual indicates that Neandertals displayed significant differences from modern humans in the thoracic spine, which adds to the differences already observed in the cervical and lumbar regions. Finally, we have also observed mild signs of osteoarthrosis, albeit to a lower degree of that present in other Neandertals such as La Chapelle-aux-Saints, La Ferrassie 1 or Shanidar 3. This is consistent with the younger adult age for Regourdou 1.

The mesosternum of the Regourdou 1 Neandertal revisited.

Fossil hominin mesosterna, while scarce, can provide useful morphological data in addition to rib remains regarding aspects of thoracic size and shape. These data, in turn, can address hypotheses related to respiratory dynamics, climatic adaptation, and ecogeographical patterning. In this study, we re-evaluate the anatomical representation of the mesosternum of the Regourdou 1 Neandertal individual that alters key aspects of the original description of the fossil remains. We compare this specimen together with the mesosterna of the Kebara 2 Neandertal male individual and the Tabun C1 Neandertal female individual to a large extant modern sample. Our study shows that the current evidence available for Neandertals indicates longer mesosterna, reflecting larger thorax sizes among Neandertals, in comparison with extant humans. Additionally, while this study weakens previous suggestions of ecogeographically mediated differences in the size and shape of upper thorax between Neandertals from the Mediterranean Levant and those deriving from Western Europe, we cannot unambiguously disprove the notion of such clinal differences.

The costal skeleton of the Regourdou 1 Neandertal

The morphology and size of the Neandertal thorax is a subject of growing interest due to its link to general aspects of body size and shape, including physiological aspects related to bioenergetics and activity budgets. However, the number of well-preserved adult Neandertal costal remains is still low. The recent finding of new additional costal remains from the Regourdou 1 (R1) skeleton has rendered this skeleton as one of the most complete Neandertal costal skeletons with a minimum of 18 ribs represented, five of which are complete or virtually complete. Here we describe for the first time all the rib remains from R1 and compare them to a large modern Euroamerican male sample as well as to other published Neandertal individuals. The costal skeleton of this individual shows significant metric and morphological differences from our modern human male comparative sample. The perceived differences include: dorsoventrally large 1st and 2nd ribs, 3rd ribs with a very closed dorsal curvature and large maximum diameters at the posterior angle, a large tubercle-iliocostal line distance in the 4th rib, thick shafts at the dorsal end of its 6th ribs, thick mid-shafts of the 8th ribs, large articular tubercles at the 9th ribs, and thick shafts of the 11th and 12th ribs. Here we also describe a new mesosternal fragment: the left lateral half of sternebral segments 4 and 5. This portion reveals that the mesosternum of R1 had a sternal foramen in its inferiormost preserved sternal segment and supports previous estimation of the total length of this mesosternum. The new costal remains from R1 support the view that Neandertals, when compared with modern humans, show a significantly different thorax, consistent with differences found in other anatomical regions such as the vertebral column and pelvis.

Analytical evidence of enamel hypomineralisation on permanent and primary molars amongst past populations

Molar Incisor Hypomineralisation (MIH) and Hypomineralised Second Primary Molars (HSPM) involve prevalent qualitative structural developmental anomalies of tooth enamel affecting the first permanent molars (and often incisors) and the second primary molars, respectively. These demarcated hypomineralised lesions of enamel manifest as white-cream or yellow-brown opacities, with possible post-eruptive localised loss of enamel. Aetiological hypotheses have involved contemporary life factors (i.e. environmental pollutant exposure or early childhood medications) in contrast to factors not limited to a specific time period (i.e. hypoxia at birth or genetic predisposition). Evidence of MIH in ancient populations would reinforce aetiological factors present for many centuries. By means of microtomographic and X-ray fluorescence analyses the present study provides evidence that (i) two archaeological specimens: “S407” (Sains-en-Gohelle, France, 12th–16th centuries) and “B335” (Beauvais, France, 15th–18th centuries) were MIH-affected, and (ii) one individual “S323” was affected by HSPM and MIH (Sains-en-Gohelle, France, 7th–11th centuries).