AAPA 2012 Meeting

In April 2012 we are presenting some posters and communications at the 81st  Annual Meeting of the American Association of Physical Anthropologists held in Portland. Here you have the complete program.

The abstracts of the presentations were already published at the American Journal of Physical Anthropology.

New dental hominoid remains from the Late Miocene locality of Can Llobateres 1 (Vallès-Penedès Basin, Catalonia, Spain).
DAVID M. ALBA, ISAAC CASANOVAS-VILAR, SERGIO ALMÉCIJA, JOSEP M. ROBLES, JÚLIA ARIAS-MARTORELL and SALVADOR MOYÀ-SOLÀ.
Excavations at the Late Miocene (9.7 Ma) locality of Can Llobateres 1 (CLL1; Vallès-Penedès Basin, Catalonia, Spain) were resumed in 2010, by focusing on the removal of sterile sediments overlying the potentially hominoid-bearing levels with the aid of an excavator machine. Although no hominoid remains were recovered, these works provided additional surface to be manually excavated in the western sector of the site, further leading to the recovery of plant remains that enabled reconstructing the paleoenvironment of Hispanopithecus laietanus. Systematic manual excavations were recently carried out in 2011, both in the eastern (classical) sector and in the new, western sector of CLL1. Although the various levels excavated were not particularly rich, after five weeks of fieldwork, 11 teeth of H. laietanus were recovered: a deciduous upper premolar from layer CLL1.1b, in the eastern sector; and 10 upper teeth from layer CLL1.2 (=CLL1.0), in the western sector. The latter teeth were found scattered over a surface of several square meters, and most of them (including incisors, premolars and molars) probably belong to a single individual. These finds represent a significant addition to the sample of dentognathic remains from CLL1, which in the future will contribute to a more complete assessment of intraspecific dental variability in this fossil hominoid. These results unambiguously confirm that the layers of CLL1 rich in fossil primate remains are not exhausted, thus being very promising for the find of additional remains of Hispanopithecus laietanus in the future. This work has been supported by the National Geographic Society (fieldwork grant #8910-11), the Generalitat de Catalunya (fieldwork grant 61636/2010, 2009 SGR 754 GRC, and BP-A 00226 to SA), and the Spanish Ministerio de Ciencia e Innovación (CGL2008-00325/BTE, CGL2010-21672/BTE, RYC-2009-04533 to DMA, and JCI-2010-08241 to ICV).
American Journal of Physical Anthropology 2012;147(S54):81.

3D geometric morphometric analysis of the proximal epiphysis of the humerus of hominoids: functional interpretation, locomotor evolution and variability.
JULIA ARIAS-MARTORELL, JOSEP M. POTAU, GAËLLE BELLO-HELLEGOUARCH and ALEJANDRO M. PÉREZ-PÉREZ.
All extant hominoids display an orthograde bodyplan, presumably mosaic-like acquired. This acquisition caused substantial modifications on the axial and appendicular skeleton. The forelimbs of orthograde primates present certain adaptive morphologies that enhance the mobility and excursion of the joints, especially at the glenohumeral region. In this study, we present a three-dimensional geometric morphometric analysis of the proximal humeral morphology in extant great apes and humans, in order to accurately describe and measure the functional and anatomical differences between these taxa at the proximal humeral region. Moreover, a fossil hominin, Australopithecus afarensis (AL 288-1), is included into the analysis to test the potential of this approach to construct locomotor inferences based on fossil material. Our analysis confirms that there are significant and quantifiable differences in proximal humeral morphology among the taxa, which has thus far largely remained unnoticed. Based on morphofunctional considerations, these anatomical differences can be correlated to differences in the locomotor repertoires of the several taxa, confirming that the proximal humerus is suitable for constructing paleobiological inferences on locomotion. Modern humans display markedly diverging features, which set them apart from both extant great apes and the fossil hominin. The proximal humeral morphology of the latter rather resembles that of orangutans, suggesting that, despite its adaptations to habitual bipedalism, the forelimb of this taxon was still functionally involved in forelimb-related arboreal behaviors. Our results for A. afarensis support that bipedal hominins evolved from arboreal ancestors instead of a knuckle-walking ancestor, which was possibly acquired independently by chimpanzees and gorillas. This research was supported by the Spanish Ministry of Education and Science (MEC) Funding for Research Projects (MEC CGL2010-15340), the Generalitat de Catalunya Funding for Consolidate Research Groups (DURSI 2009SGR-00884), and the Predoctoral Fellowship Grant Program of the University of Barcelona APIF-UB2009/10.
American Journal of Physical Anthropology 2012;147(S54):85.

How to distinguish and analyse locomotor groups in the Hominoidea: analysis of supraspinous and infraspinous fossae with geometric morphometrics, 3D laser scanning and new methodologies to measure muscle mass.
GAËLLE BELLO-HELLEGOUARCH, JOSEP M. POTAU, JÚLIA ARIAS-MARTORELL and ALEJANDRO M. PÉREZ-PÉREZ.
Extant hominoids share an orthograde corporal pattern, which allows the free movement of the glenohumeral joint, permitting the appearance of new forms of locomotion.
This study provides a quantitative analysis of the posterior side of the hominoid scapula, including modern humans. Our objective is to find patterns of variation in scapular shape through a multivariate analysis of morphological features in order to distinguish different types of locomotion observed in hominoids and thus to be able to better understand the locomotor patterns of fossil taxa. We apply 2D geometric morphometrics, 2D areas, 3D real areas, the classical spinal fossae index, and compare the results with muscular weights obtained from dissections of primate cadavers. Our results suggest that knuckle-walking was independently acquired in Pan and Gorilla, and that the last common ancestor of humans and chimpanzees was mainly arboreal, with a shoulder morphology similar to that of orangutans. We conclude that the new methodologies applied are useful tools to study the morphology of the scapula and its muscles. The detailed analysis of the morphology of the posterior side of the scapula is particularly suitable to differentiate the types of locomotion observed in hominoids. Moreover, even if one should be careful about inferring conclusions based exclusively on the study of bones because a substantial part of the data about soft tissues is lost, by using our methodologies it is possible to estimate quite accurately whether a scapula (based only on the morphology of this bone) belongs or not to a particular locomotor group. This research was supported by the Spanish Ministry of Education and Science (MEC) Funding for Research Projects (MEC CGL2010-15340), the Generalitat de Catalunya Funding for Consolidate Research Groups (DURSI 2009SGR-00884), and the Predoctoral Fellowship Grant Program of the Ministry of Education and Science (MEC) FPU (AP2008-00877).
American Journal of Physical Anthropology 2012;147(S54): 95.

Geometric morphometric analysis of the upper first molar in modern hunter-gatherer populations.
ALEJANDRO ROMERO, FERNANDO V. RAMIREZ ROZZI, MAITE ARTERO, STÉPHANIE TORRIJO, NURIA LÓPEZ, JOAQUÍN DE JUAN and ALEJANDRO PÉREZ-PÉREZ.
Tooth morphology shows a large variability; however it remains unclear which is the relation, if any, between it and environmental conditions. In this exploratory work we start to observe if tooth morphology varies following large climatic conditions. The morphology of upper first molar (M1) of six modern hunter-gatherer populations from hot-humid (n=18; Central African Baka-Aka pygmies and Andaman islanders), hot-dry (n=20; South African Khoesan and south-western Australian Aborigines) and cold-humid (n=17; Greenland Inuit and Yamana from Tierra del Fuego) climates was analysed by Principal components analysis (PCA) of Procrustes shape coordinates and by canonical variates (CV). The PCA of the relative warp scores shows that populations living in cold-humid environments characterize by an expanded and square occlusal polygon with a reduced hypocone, whereas those inhabiting in hot (dry and humid) climates present a bigger hypocone and a reduction in the distance between the protocone and the hypocone. Changes in shape are not allometric. The canonical analysis enables to distinguish clearly the Inuit from Yamana (Goodall’s F-test P<0.001). Populations from hot climates distribute along the first CV axe (41.3% of the total variance), Khoesan differs from SW Australian Aborigines (P<0.001) and Andaman islanders distinguish from Baka-Aka pygmies (P<0.001). This work is only based on a single tooth class and random factors cannot be disregarded, however the results seem to suggest that differences in the morphology of the upper M1 are not related to climatic conditions and others factors can probably better explain it. This study was funded by Spanish GV and MEC, grant numbers BEST/2009/258, CGL2010-15340, CGL2011-22999.
American Journal of Physical Anthropology 2012;147(S54): 251-252.