title: A geometric morphometrics comparative analysis of Neandertal humeri (epiphyses-fused) from the El Sidrón cave site (Asturias, Spain).
abstract: A new collection of 49,000 year old Neandertal fossil humeri from the El Sidrón cave site (Asturias, Spain) is presented. A total of 49 humeral remains were recovered, representing 10 left and 8 right humeri from adults, adolescents, and a juvenile (not included in the analyses). 3D geometric morphometric (GM) methods as well as classic anthropological variables were employed to conduct a broad comparative analysis by means of mean centroid size and shape comparisons, principal components analysis, and cluster studies. Due to the fragmentary nature of the fossils, comparisons were organized in independent analyses according to different humeral portions: distal epiphysis, diaphysis, proximal epiphysis, and the complete humerus. From a multivariate viewpoint, 3D-GM analyses revealed major differences among taxonomic groups, supporting the value of the humerus in systematic classification. Notably, the Australopithecus anamensis (KP-271) and Homo ergaster Nariokotome (KNM-WT 15000) distal humerus consistently clusters close to those of modern humans, which may imply a primitive condition for Homo sapiens morphology. Australopithecus specimens show a high degree of dispersion in the morphospace. The El Sidrón sample perfectly fits into the classic Neandertal pattern, previously described as having a relatively wide olecranon fossa, as well as thin lateral and medial distodorsal pillars. These characteristics were also typical of the Sima de los Huesos (Atapuerca) sample, African mid-Pleistocene Bodo specimen, and Lower Pleistocene TD6-Atapuerca remains and may be considered as a derived state. Finally, we hypothesize that most of the features thought to be different between Neandertals and modern humans might be associated with structural differences in the pectoral girdle and shoulder joint.
authors.affiliation: Group of Paleoanthropology MNCN-CSIC, Department of Paleobiology, Museo Nacional de Ciencias Naturales, CSIC, Calle José Gutiérrez Abascal 2, 28006 Madrid, Spain. Electronic address: arosas@mncn.csic.es.
authors.forename: Antonio
authors.initials: A
authors.lastname: Rosas
authors.affiliation: Group of Paleoanthropology MNCN-CSIC, Department of Paleobiology, Museo Nacional de Ciencias Naturales, CSIC, Calle José Gutiérrez Abascal 2, 28006 Madrid, Spain.
authors.forename: Laura
authors.initials: L
authors.lastname: Pérez-Criado
authors.affiliation: Group of Paleoanthropology MNCN-CSIC, Department of Paleobiology, Museo Nacional de Ciencias Naturales, CSIC, Calle José Gutiérrez Abascal 2, 28006 Madrid, Spain.
authors.forename: Markus
authors.initials: M
authors.lastname: Bastir
authors.affiliation: Group of Paleoanthropology MNCN-CSIC, Department of Paleobiology, Museo Nacional de Ciencias Naturales, CSIC, Calle José Gutiérrez Abascal 2, 28006 Madrid, Spain.
authors.forename: Almudena
authors.initials: A
authors.lastname: Estalrrich
authors.affiliation: Institut Català de Paleoecologia Humana i Evolució Social (IPHES), Àrea de Prehistòria, Universitat Rovira i Virgili, Zona Educacional 4 - Campus Sescelades URV (Edifici W3), Unidad Asociada al CSIC, 43007 Tarragona, Spain.
authors.forename: Rosa
authors.initials: R
authors.lastname: Huguet
authors.affiliation: Group of Paleoanthropology MNCN-CSIC, Department of Paleobiology, Museo Nacional de Ciencias Naturales, CSIC, Calle José Gutiérrez Abascal 2, 28006 Madrid, Spain.
authors.forename: Antonio
authors.initials: A
authors.lastname: García-Tabernero
authors.affiliation: Museo Anatómico, Departamento de Anatomía Humana, Universidad de Valladolid, Calle Ramón y Cajal 7, 47005 Valladolid, Spain.
authors.forename: Juan Francisco
authors.initials: JF
authors.lastname: Pastor
authors.affiliation: Área de Prehistoria, Department of History, Universidad de Oviedo, Calle Teniente Alfonso Martínez s/n, 33011 Oviedo, Spain.
authors.forename: Marco
authors.initials: M
authors.lastname: de la Rasilla
mesh_terms: D000818:Animals; D005075:Biological Evolution; D004838:Epiphyses / Q000033:anatomy & histology*; D005260:Female; D005580:Fossils; D049690:History, Ancient; D006811:Humerus / Q000033:anatomy & histology*; D008297:Male; D059125:Neanderthals / Q000033:anatomy & histology*; D010802:Phylogeny; D012737:Sex Factors; D013030:Spain
keywords: Humerus; Neandertal; Sexual dimorphism; Trait polarity