It also sheds light on the origin of the Neanderthals. The latest data obtained from paleontological and geomorphological studies place the Montmaurin-La Niche mandible in a chronologically intermediate position between the fossils of the Middle Pleistocene and the Neanderthals.
The micro-computed axial tomography (microCT) technique has enabled the molars in this mandible to be compared with the external and internal structures of over 400 other molars from the European, Asian and African Pleistocene and Holocene.
The analysis has revealed that, while the mandible is more closely related to African and Eurasian populations from the Early and Middle Pleistocene, the enamel and dentine morphology and pulp cavity proportions are similar to those in Neanderthals.
“Nevertheless, the absolute and relative enamel thickness values (2D and 3D) show greater affinity with those exhibited by certain Early Pleistocene hominins”, says Martínez de Pinillos.
Over recent decades, finds of human fossil remains from the European Middle Pleistocene have prompted the debate on the evolutionary scenario of the genus Homo on that continent to be reopened. “The great variability we find among the European Middle Pleistocene fossils cannot be ignored in studying human evolution on our continent”, states Martín-Francés.
This variability in European Middle Pleistocene populations could indicate different migrations at different times and/or fragmentation of the population though it might also be due to possible hybridization between residents and new settlers.