Neanderthal child's maxilla from Baume Moula-Guercy (Soyons, Ardèche, France).

This article provides an ontogenetically-based comparative description of the Guercy 3 partial child's maxilla with Rdm2 -RM1 and unerupted RI2 -RP4 from Baume Moula-Guercy (MIS 5e) and examines its affinities to European and Middle Eastern Middle-to-Late Pleistocene (≈MIS 14-MIS 1) Homo. Description of the Guercy 3 maxilla and dentition (7.0 year ± 0.9 month) is based on observations of original fossils, casts, CT scans, literature descriptions, and virtual reconstructions. Our ontogenetic sample comprises a Preneanderthal-Neanderthal group and a Homo sapiens group. These groups are subdivided into (1) Preneanderthals (≈MIS 14-9), Early Neanderthals (MIS 7-5e), and Late Neanderthals (MIS 5d-3), and (2) Middle (MIS 5), Upper (MIS 3-2), and Late Upper Paleolithic (≈MIS 1), and recent H. sapiens. Standard techniques were employed for measurements and developmental age determinations.The Guercy 3 maxilla lacks changes found in Late Neanderthals, including the positioning of the root of the zygomatic process, infraorbital and nasal plates, premaxilla, buccal and labial alveolus, maxillary sinus, nasal cavity, and verticality of anterior tooth implantation. The morphology of the Guercy 3 maxilla more closely approximates that of Sima de los Huesos Preneanderthals, while the dentition more closely approximates the Early-Late Neanderthal condition. Maxillary remains of children and juveniles between MIS 14-MIS 5e are rare, and the available sample is fragmentary and distorted. Although fragmentary, the Guercy 3 maxilla is undistorted and provides new insights into the evolution of the midface in Neanderthals.