The Late Middle Pleistocene fossils from Montmaurin (Haute-Garonne, France). A contribution to the question of the emergence of the Neandertal lineage

Abstract

Hominin fossils were discovered in the Montmaurin caves (S-W of France) in 1950’s. Among them, the mandible from La Niche was attributed to a preneandertal (i.e. H. heidelbergensis). Until now, except this specimen, the others discovered in the same site (two thoracic vertebras, one right tibia) are quite unpublished while the fossils from a very close cavity called Coupe-Gorge (a right maxillary bone bearing C-P4, 3 isolated teeth and a fragmentary juvenile mandible) were forgotten. This is the purpose of this study to highlight such “unknown” fossils. Attributed to the Late Middle Pleistocene, they belong to the current debate on the origins of the Neandertal lineage. That’s why a new examination was done. Results show a mixture of archaic and Neandertal features not only on the La Niche mandible but also on the Coupe-Gorge maxillary bone. The former shows a derived teeth pattern and a primitive mandibular corpus (well-marked planum alveolare on the inner part of the symphysis, foramen mentale at the level of P4). The latter is not as inflexed as in Neandertals (the nasal bones are oblique, not horizontal) but is similar to them by its sloped or bilevel nasal floor. The Montmaurin fossils evidence a not fully Neandertal form during the Late Middle Pleistocene although this species is supposed to emerge at that time. It suggests two possibilities: 1- this event occurred later or 2- an archaic group co-existed in parallel with the first Neandertals.