Mugharet el'Aliya: Affinities of an enigmatic north African Aterian maxillary fragment

Objectives

This study uses a virtual framework to examine the left maxillary fragment of the juvenile fossil from Mugharet el'Aliya, Morocco, found in association with an Aterian lithic industry. Previously, this fossil had been ascribed to modern humans or the Neanderthal lineage based on its “archaic”/“Neanderthal-like” features and apparent large size. Here, we conducted a novel 3D shape comparative analysis of the maxillary fragment to clarify its taxonomic affinities with regard to its size and ontogeny.

Materials and Methods

Eighty Computed Tomography and surface scans representing ontogenetic samples of Homo sapiens and Homo neanderthalensis were used to capture species-specific differences. The toolkit of geometric morphometrics in combination with surface registration and an elastic iterative closest point algorithm were used to create a dataset of meshes with an identical number of corresponding vertices for the maxillae. Multivariate statistics were applied to Procrustes superimposed coordinates derived from the vertices of this dataset.

Results

Our analysis showed affinities of the Mugharet el'Aliya individual with our H. sapiens sample, especially with a subadult individual from Qafzeh. No size-independent affinities with Neanderthals of comparable dental age could be identified.

Discussion

Our results add to the evidence connecting fossils from western Asia, especially Qafzeh and Skhul, and the North African Aterian. Furthermore, Mugharet el'Aliya adds to our knowledge of the ontogenetic development of adult morphology that is frequently used to characterize hominin groups, for example, Neanderthals and modern humans.