"Ouranopithecus macedoniensis" (late Miocene, Greece): analysis of mandibular fragments using 3D geometric morphometrics / Melania Ioannidou

Ouranopithecus  macedoniensis (late  Miocene,  Greece):  analysis  of mandibular fragments using 3D geometric morphometrics / Melania Ioannidou, in colloque "1st Virtual Conference for Women Archaeologists and Paleontologists. Nouveaux apports à l’étude des populations et environnements passés" organisé par le laboratoire Travaux et Recherches Archéologiques sur les Cultures, les Espaces et les Sociétés (TRACES) de l’Université Toulouse Jean Jaurès et le laboratoire Paléontologie Évolution Paléoécosystèmes (PALEVOPRIM) de l'Université de Poitiers, sous la responsabilité scientifique de Julie Bachellerie, Ana Belén Galán López (Traces), Émilie Berlioz et Margot Louail (Palevoprim). Université Toulouse Jean Jaurès, 8-9 mars 2021. [Conférence enregistrée à distance].Session 1 : Morphological variability, taxonomy and adaptations.

Material belonging to the late Miocene hominoid Ouranopithecus macedoniensis has been poorly analyzed using advanced techniques. This study aims to explore mandibular shape variation between Ouranopithecus macedoniensis and a comparative sample of extant great apes, using three-dimensional (3D) geometric morphometrics. Additional aims include examining homogeneity within Ouranopithecus, especially as it relates to sexual dimorphism, and in comparison to those of the extant great apes. Lastly, we address the effects of size-related shape differences among taxa. Apart from four Ouranopithecus partial mandibles, which preserve both corpora and the symphysis (two female and two male), the comparative sample consists of digitized mandibles from adult extant great apes (Gorilla, Pan and Pongo). The analysis includes the registration of 3D landmarks on the mandibular body and the hemimandible. Multivariate statistical analyses were conducted, including ordination analyses, intra-specific Procrustes distances pairs, pairwise male-female centroid size differences, and correlation analyses. Our results showed that the mandibular shapes of the male and female specimens of Ouranopithecus are quite similar, although they differ in size. Ouranopithecus also showed some similarities in mandibular shape to the larger great apes, Gorilla and Pongo. Additionally, Ouranopithecus displays a similar –and possibly even greater– degree of sexual dimorphism to Pongo. Lastly, the results of ourcorrelation analyses indicated that some PCs were significantly correlated with size, while the degree of correlation varied from moderate to substantial. This study suggests that some of the mandibular morphological similarities of Ouranopithecus to the larger great apes may reflect similarities in size. Despite the presence of sexual dimorphism in size, the shape of the mandibular body is homogenous between male and female O. macedoniensis.