A virtual assessment of the suprainiac depressions on the Eyasi I (Tanzania) and Aduma ADU-VP-1/3 (Ethiopia) Pleistocene hominin crania.

Despite a steady increase in our understanding of the phenotypic variation of Pleistocene Homo, debate continues over phylogenetically informative features. One such trait is the suprainiac fossa, a depression on the occipital bone above inion that is commonly considered an autapomorphy of the Neanderthal lineage. Challenging this convention, depressions in the suprainiac region have also been described for two Pleistocene hominin crania from sub-Saharan Africa: Eyasi I (Tanzania) and ADU-VP-1/3 (Ethiopia). Here, we use a combined quantitative and qualitative approach, using µCT imaging, to investigate the occipital depressions on these specimens. The results show that neither the external nor the internal morphologies of these depressions bear any resemblance to the Neanderthal condition. A principal component analysis based on multiple thickness measurements along the occipital squama demonstrates that the relative thickness values for the internal structures in Eyasi I and ADU-VP-1/3 are within the range of Homo sapiens. Thus, our results support the autapomorphic status of the Neanderthal suprainiac fossa and highlight the need to use nuanced approaches and multiple lines of evidence.

A virtual assessment of the proposed suprainiac fossa on the early modern European calvaria from Cioclovina, Romania.

OBJECTIVES: The calvaria from Cioclovina (Romania) has been argued to possess some traits commonly ascribed to individuals belonging to the Neanderthal lineage, including a suprainiac fossa. However, its supranuchal morphology has only been evaluated with a qualitative analysis of the ectocranial surface. We evaluate whether the morphology of the supranuchal area of this specimen is homologous to the Neanderthal condition. MATERIALS AND METHODS: We described in detail the external morphology, and, using computed tomography, investigated the internal morphology of the Cioclovina supranuchal area. We took measurements of the internal structures and calculated their relative contributions to total cranial vault thickness, which were compared to published data and evaluated with a principal component analysis (PCA). RESULTS: The Cioclovina supranuchal region is characterized by superficial resorption present on the outer layer of the external table. Neither the diploic layer nor the external table decrease in relative thickness in the area above inion. In the PCA, Cioclovina falls within the convex hulls of recent modern Homo sapiens. DISCUSSION: Our results show that the morphology of the Cioclovina supranuchal region does not correspond to the external and internal morphology of the typical Neanderthal suprainiac fossa. It cannot be characterized as a depression but rather as an area presenting superficial bone turnover. Together with earlier results, there is little phenotypic evidence that Cioclovina has high levels of Neanderthal ancestry. Our study demonstrates the usefulness of this quantitative method in assessing proposed Neanderthal-like suprainiac depressions in Upper Paleolithic and other fossil specimens.

La Ferrassie 8 Neandertal child reloaded: New remains and re-assessment of the original collection.

The first evidence of the partial infant Neandertal skeleton La Ferrassie 8 (LF8) was discovered in 1970, although most of the remains were found in 1973 as part of the 1968-1973 work at the site by H. Delporte. This individual and the other Neandertal children from La Ferrassie were published in the early 1980s by J.-L. Heim, and since then LF8 has been regarded as coming from a poorly documented excavation. The recent rediscovery of the box that contained the hominin bones given by Delporte to Heim in the Muséum national d'Histoire naturelle (MNHN) collection provided new fossils and helped to locate LF8 in the site: level M2 in square 1. Two visits to the Musée d'Archéologie nationale et Domaine national de Saint-Germain-en-Laye (MAN) yielded additional fossil remains from both the 1970 and 1973 excavations and resulted in the discovery of all of the notes from the excavation of H. Delporte between 1968 and 1973. Here the new fossil remains (47 after performing all possible refits), representing significant portions of the cranium, mandible, and vertebral column together with fragmentary hand and costal remains, are described. Unsurprisingly, the morphology of the bony labyrinth and of a complete stapes from the nearly complete left temporal show clear Neandertal affinities. Additionally, a complete reassessment of the original LF8 collection has resulted in the identification of several errors in the anatomical determination. Despite the significant increase in the anatomical representation of LF8, the skeletal remains are still limited to the head, thorax, pelvis, and four hand phalanges, with some very fragile elements relatively well preserved. Different hypotheses are proposed to explain this anatomical representation, which can be tested during future fieldwork.

Influence of lower limb configuration on walking cost in Late Pleistocene humans.

It has been proposed that Neandertals had about 30% higher gross cost of transport than anatomically modern humans (AMH) and that such difference implies higher daily energy demands and reduced foraging ranges in Neandertals. Thus, reduced walking economy could be among the factors contributing to the Neandertals' loss in competition with their anatomically modern successors. Previously, Neandertal walking cost had been estimated from just two parameters and based upon a pooled-sex sample. In the present study, we estimate sex-specific walking cost of Neandertals using a model accounting for body mass, lower limb length, lower limb proportions, and other features of lower limb configuration. Our results suggest that Neandertals needed more energy to walk a given distance than did AMH but the difference was less than half of that previously estimated in males and even far less pronounced in females. In contrast, comparison of the estimated walking cost adjusted to body mass indicates that Neandertals spent less energy per kilogram of body mass than AMH thanks to their lower limb configuration, males having 1-5% lower and females 1-3% lower mass-specific net cost of transport than AMH of the same sex. The primary cause of high cost of transport in Neandertal males is thus their great body mass, possibly a consequence of adaptation to cold, which was not fully offset by their cost-moderating lower limb configuration. The estimated differences in absolute energy spent for locomotion between Neandertal and AMH males would account for about 1% of previously estimated daily energy expenditure of Neandertal or AMH males.