title: Morphological affinities of the proximal humerus of Epipliopithecus vindobonensis and Pliopithecus antiquus: suspensory inferences based on a 3D geometric morphometrics approach.
abstract: Suspension plays a major adaptive role in shaping primate postcranial morphology, which therefore enables this positional behavior to be inferred in extinct taxa. The proximal humerus stands as a key region for inferring forelimb suspensory capabilities because its morphology can be effectively linked, from a functional viewpoint, to differences in suspension use between primate taxa. Here we provide an assessment of the suspensory capabilities of two pliopithecoids (Epipliopithecus vindobonensis and Pliopithecus antiquus) by means of a 3D geometric morphometric analysis of proximal humeral shape. The comparative sample includes proximal humeri from eight extant anthropoid genera, as well as other extinct catarrhines (the propliopithecoid Aegyptopithecus zeuxis, the stem hominoid Nyanzapithecus vancouveringorum, and an unascribed small catarrhine, GSP 28062, from the Middle Miocene of Pakistan). Body mass estimates based on allometric regressions of humeral head superoinferior diameter are also provided. Our results support some degree of forelimb suspensory behaviors for Epipliopithecus and GSP 28062. In contrast, and unlike previous qualitative assessments, our analysis shows that P. antiquus has a distinct glenohumeral morphology, much closer to that displayed by generalized arboreal quadrupeds with no evidence of suspensory adaptations (as in Aegyptopithecus and stem hominoids from Africa).
authors.affiliation: Unitat d'Antropologia (Departament de Biologia Animal), Universitat de Barcelona, Av. Diagonal 643, 08028 Barcelona, Spain. Electronic address: j.arias.martorell@ub.edu.
authors.forename: Julia
authors.initials: J
authors.lastname: Arias-Martorell
authors.affiliation: Institut Català de Paleontologia Miquel Crusafont, Universitat Autònoma de Barcelona, Edifici Z (ICTA-ICP), Carrer de les Columnes s/n, Campus de la UAB, Cerdanyola del Vallès, 08193 Barcelona, Spain. Electronic address: david.alba@icp.cat.
authors.forename: David M
authors.initials: DM
authors.lastname: Alba
authors.affiliation: Unitat d'Anatomia Humana i Embriologia, Facultat de Medicina, Universitat de Barcelona, C/ Casanova 143, 08036 Barcelona, Spain. Electronic address: jpotau@ub.edu.
authors.forename: Josep M
authors.initials: JM
authors.lastname: Potau
authors.affiliation: Unitat d'Antropologia (Departament de Biologia Animal), Universitat de Barcelona, Av. Diagonal 643, 08028 Barcelona, Spain. Electronic address: gaellebh@yahoo.com.
authors.forename: Gaëlle
authors.initials: G
authors.lastname: Bello-Hellegouarch
authors.affiliation: Unitat d'Antropologia (Departament de Biologia Animal), Universitat de Barcelona, Av. Diagonal 643, 08028 Barcelona, Spain. Electronic address: martinez.perez-perez@ub.edu.
authors.forename: Alejandro
authors.initials: A
authors.lastname: Pérez-Pérez
mesh_terms: D000717:Anatomy, Comparative; D000818:Animals; D005075:Biological Evolution; D001696:Biomechanical Phenomena; D051079:Catarrhini / Q000033:anatomy & histology* / Q000502:physiology; D005580:Fossils; D015186:Hominidae / Q000033:anatomy & histology / Q000502:physiology; D006811:Humerus / Q000033:anatomy & histology* / Q000502:physiology; D021621:Imaging, Three-Dimensional; D008124:Locomotion
keywords: Fossil primates; Hominoidea; Humeral morphology; Locomotion; Pliopithecoidea; Shape analysis