Morphology, pathology, and the vertebral posture of the La Chapelle-aux-Saints Neandertal

Abstract

Although the early postural reconstructions of the Neandertals as incompletely erect were rejected half a century ago, recent studies of Neandertal vertebral remains have inferred a hypolordotic, flat lower back and spinal imbalance for them, including the La Chapelle-aux-Saints 1 skeleton. These studies form part of a persistent trend to view the Neandertals as less “human” than ourselves despite growing evidence for little if any differences in basic functional anatomy and behavioral capabilities. We have therefore reassessed the spinal posture of La Chapelle-aux-Saints 1 using a new pelvic reconstruction to infer lumbar lordosis, interarticulation of lower lumbar (L4-S1) and cervical (C4-T2) vertebrae, and consideration of his widespread age-related osteoarthritis. La Chapelle-aux-Saints 1 exhibits a pelvic incidence (and hence lumbar lordosis) similar to modern humans, articulation of lumbar and cervical vertebrae indicating pronounced lordosis, and Baastrup disease as a product of his advanced age, osteoarthritis, and lordosis. Our findings challenge the view of generally small spinal curvatures in Neandertals. Setting aside the developmentally abnormal Kebara 2 vertebral column, La Chapelle-aux-Saints 1 is joined by other Neandertals with sufficient vertebral remains in providing them with a fully upright (and human) axial posture.

Rib cage anatomy in Homo erectus suggests a recent evolutionary origin of modern human body shape

“…The wider Kebara 2 Neanderthal rib cage is also outside, but close to, the 95% confidence ellipse of the modern human sample (Fig. 4), supporting suggestions that the wide, deep thorax of Neanderthals is a primitive feature within genus Homo and shared with H. erectus [16][17][18] , despite recent suggestions about the potentially modern human-like spinal curvature of Neanderthals 37 . Mean 24.4% of total variance) reflect interspecific differences, including relatively 'vertically' shorter vertebral bodies and more horizontally oriented spinous processes in KNM-WT 15000 than in modern human means.…”

Three-dimensional geometric morphometrics of thorax-pelvis covariation and its potential for predicting the thorax morphology: A case study on Kebara 2 Neandertal

“…As a consequence, there could be more than one way to align the thoracic elements depending on each researcher's criteria, which could affect rib orientation and declination, so modifying the anteroposterior, mediolateral and craniocaudal diameters of the articulated thorax. These different researcher's assumptions might also be based on different interpretations of the body shapes of extinct hominins, which is then reflected in their reconstructions (Schmid, 1983;Bonmatí et al, 2010;Arsuaga et al, 2015;Latimer et al, 2016;Gómez-Olivencia et al, 2018;Haeusler et al, 2019). This reinforces the necessity of developing new and complementary approaches for such reconstructions.…”

External auditory exostoses among western Eurasian late Middle and Late Pleistocene humans

“…The only Late Pleistocene individual with grade 3 exostoses, Shanidar 1, is an older adult based on dental wear and pubic symphyseal morphology [6]. The older La Chapelle-aux-Saints 1, based on its auricular surface [57], exhibits grade 2 EAE on one side, but grade 1 in the other meatus. The other individuals with grade 2 exostoses, Krapina 39.1, Spy 1, Tabun 1 and Iboussières A, are all younger adults, the latter three based on dental wear and the first on the age distribution of the Krapina sample [58].…”