Etude des restes mandibulaires d’Homo neanderthalensis de Guattari, Caverna delle Fate et San Francesco d’Archi

The current data on the peopling of the Italian peninsula suggest a delay in the acquisition of Neanderthals’ autapomorphies, due to geographic isolation. In Europe, the first Neanderthals’ derived features appeared around 450 ka BP whereas in Italy the specimens show an archaic morphology by the presence of plesiomorphic features and the first autapomorphies will be individualized from the MIS 9 (350 ka ca.). We propose in this work a revision of Italian mandibular fossil remains attributed to Homo neanderthalensis: Guattari II, Guattari III, Fate II, Fate III and Archi I, in order to replace them in the European evolutionary context through a morphological and a morphometrical study. The presence of immature specimens (Fate II and Archi I) involved the study of Neanderthals’ developmental pattern which divided the scientific community: some authors define Neanderthal ontogenesis as similar to the one of modern humans and others highlight divergent evolutionary trajectories based on maturation precocity in Neanderthal groups. The reference sample is composed of 72 adult specimens consisting of 24 Homo neanderthalensis, 41 modern humans and 6 fossils from the Middle Pleistocene. Immature specimens are represented by 16 Homo neanderthalensis and 44 modern humans and classified into five growth stages, from an incomplete deciduous dentition (stage 1) to the beginning of the eruption of the third molar (stage 5). The morphological study is based on the evaluation of 40 relevant features for evidencing evolution pattern. We complete this analysis with linear morphometric through the comparison of 20 measurements and geometric morphometric based on the comparison of symphyseal outlines with Elliptic Fourier Analysis, which we have adapted to this specific study. The results obtained allowed to confirm that first of all the accretion model of Neanderthals’ evolution is identifiable in Italy. In fact, Archi and Fate II mandibles show a discrepancy. Fate II is chronologically more ancient but older, and doesn’t have as derived features as those observed in Archi. Second of all, at the European level, we observe a discrepancy in the expression of features, for example in Guattari mandibles we can see a persistence of plesiomorphic traits as observed in the cranium Guattari I. Furthermore, these specimens show a high inter-individual variability which is discussed in this present work. A morphological pattern has also been identified in the Caverna delle Fate and in the Hortus human remains characterized by a gracility of the mandibular corpus. Finally, the study of growth and development pattern allowed to highlight differences between Neanderthals and modern human infants from the same dental age not only on the general size of the mandible but also on the shape of the symphysis profile.