The Grotta Guattari mandibular remains in the Italian human evolutionary context: A morphological and morphometrical overlook of the Neanderthal jaw

Abstract

Within the Italian human fossil record, the mandibular remains Guattari 2 and Guattari 3 are representatives of Neanderthal populations living in the Italian peninsula from the beginning of the MIS 3. These were recovered from the Mount Circeo and date between ca. 57 and 51 B.P. The integrity and the contemporaneity of these two human remains make them suitable candidates for intraspecific variability investigation.In the present study, we provide a detailed morphological and morphometrical description of these specimens. This is supported by an analysis and comparison of the symphysis profile with a reference collection composed of modern human, Neanderthals and Middle Pleistocene hominins. In terms of morphology, both specimens show Neanderthal derived features such as a wide retromolar space and an anterior position of the mental foramen with, however, some inter-individual differences in terms of expression of features. Guattari 2 shows a general morphology which could be integrated in the range of Neanderthals from MIS3-4. On the other hand, Guattari 3 present a morphology closer to more ancient Neanderthals (MIS4-5).Mandibular remains constitute one of the most variable elements of the skeleton. The reason of such variability could be explained by several factors: sexual dimorphism, inter-individual variability or differences in chronology, which will be tested in this study. The reassessment of Guattari 2 and 3 has the potential to shed new light on the morphology of mandibular fossil specimens from the Italian peninsula, and increase our knowledge of the mandibular variability of the Neanderthals.