Ongoing Research on the DIK-1-1 Skeleton and New Data on the Deciduous Dentition

S • A3 A 3D geometric Morphometric Analysis of the Morphological Evolution of the Cranial base and Floor in Homo Markus Bastir, Department of Paleobiology, Museo Nacional de Ciencias Naturales, CSIC, SPAIN Philipp Gunz, Department of Human Evolution, Max-Planck-Institute for Evolutionary Anthropology, GERMANY Antonio Rosas, Department of Paleobiology, Museo Nacional de Ciencias Naturales, CSIC, SPAIN Katerina Harvati, Department of Human Evolution, Max-Planck-Institute for Evolutionary Anthropology, GERMANY Jean-Jacques Hublin, Department of Human Evolution, Max-Planck-Institute for Evolutionary Anthropology, GERMANY Until recently, basicranial shape has been mainly measured by different versions of cranial base angles, which assess angular relationships between pre-sellar and post-sellar basicranial components in the midline. These angles, however, completely ignore changes at the lateral cranial floor. Here, we present the first results of an ongoing line of research using geometric morphometrics and virtual anthropological techniques to analyze evolutionary variation of surface morphology of the cranial fossae. To this end we collected 158 3D-landmarks and sliding semilandmarks on the anterior and middle cranial fossae and the midline cranial base of modern humans and Pleistocene hominins. Preliminary results suggest different modifications of the midline base and lateral floor between the Homo erectus s. l. configuration and Neanderthals on the one hand and modern humans on the other. These basicranial differences appear also integrated with facial morphology. In either group the midline base becomes lowered with respect to the lateral cranial floor and the medio-lateral dimensions of the anterior and middle cranial fossae become expanded. In Neanderthals, however, the midline base is also shifted anteriorly—a shift that we do not observe in modern humans. These findings underline that understanding the evolution of the cranial base in Homo is important not only because morphological changes at the lateral basicranium may be related to modifications of brain morphology but also because changes in brain shape could potentially interact with facial morphology via the basicranial floor. Acknowledgements: Funding: This research is supported by CGL-2006-02131 (MEC, Spain), MRTN-CT-2005-019564 (EVAN), and the Max Planck Society. lumbar lordosis and the Posture of la Chapelle-aux-Saints Ella Been, Anatomy and Anthropology, Tel Aviv University, ISRAEL Hayuta Pessah, Anatomy and Anthropology, Tel Aviv University, ISRAEL Ever since the discovery of the La Chapelle-aux-Saints Neandertal, the question of its posture has been under debate. Although bipedality has never been in question, the thinking about the fine details of its posture has been swinging back and forth between two opposing interpretations. One sees the posture of La Chapelle-aux-Saints as essentially modern, associated with fully upright posture (Trinkaus 1985), and the other, as incompletely erect, with bent posture and an inefficient bipedal gait (Boule 1911–1913). As lumbar lordosis plays an important role in upright posture, calculating the lordotic angle of the lumbar spine of La Chapelle-auxSaints can contribute to our understanding of its posture. We calculated the lumbar lordosis angle of La Chapelle-aux-Saints by using a linear regression model that was specifically developed for this specimen. The regression model is based on the close correlation between the lordotic curvature and the orientation of the articular processes in the lumbar spines of living primates (modern humans and nonhuman primates). Our findings indicate that the lumbar lordosis angle of La Chapelle-aux-Saints is at the lower spectrum of lordosis found in modern humans. This finding supports Boule’s conclusion (1911–1913) that the lumbar curvature of La Chapelleaux-Saints was less pronounced than that of the majority of modern humans. Yet, this finding alone does not indicate bent posture and insufficient bipedal gait. Acknowledgements: The authors wish to thank Mr. Philipe Mencier, Mr. Mario Chech, and Mr. Antuan Chech, Musée de l’Homme, Paris, for enabling us to study skeletal material in their care. Special thanks to Prof. Patricia Kramer and Prof. Yoel Rak, for their help and support. References Cited: Boule, M. 1911–1913. L’Homme Fossile de La Chapelle-aux-Saints. Ann. Paleont. 6: 11–172. Trinkaus, E. 1985. Pathology and the posture of the La Chapelle-aux-Saints Neandertal. American Journal of Physical Anthropology 67: 19–41. Reevaluation of Faunal Turnovers in the Southern levant During the last glacial and the Effects of Climatic-Forcing on hominin Population Dynamics Miriam Belmaker, Department of Anthropology, Harvard University, USA Evidence for faunal turnovers has been related to climatic forcing as a cause for dispersal/extinction of hominins in the Southern Levant (Shea 2008). Others (Jelinek 1980; 1982), have suggested that inter-site variation in Middle Paleolithic (MP) micromammal fauna reflects spatial differences within the region. Distinction between these hypotheses has implications for understanding continuity vs. turnover in hominin taxa during this time period. Since the original analysis of micromammal faunal turnovers in Southwest Asia (Tchernov 1998), a wealth of paleoclimatic proxies have been studied and cave sediments have been dated. This new data enables reevaluation of the hypothesis that climate-induced micromammal turnovers were a common feature in the Upper Pleistocene of the Southern Levant. This study presents a two-pronged approach to test for microfaunal turnovers in the MP of the Southern Levant. First, I developed a null model by analyzing the distribution of extant rodent communities across different habitats in correlation with climatic variables. A4 • PaleoAnthropology 009 Second, I analyzed the distribution of taxa from micromammal assemblages in the Southern Levant spanning MIS 5–3 in comparison to the null model distribution and to local paleoclimatic proxies. Distribution of modern rodents has shown that presence-absence patterns of taxa vary along rainfall gradients in east-west and north-south trajectories and thus can be used to distinguish between Mediterranean, semi-arid, and arid regions in the Southern Levant. Analysis of MP micromammal assemblages suggests that intersite differences do not necessarily reflect regional faunal turnovers but are consistent with the spatial environmental mosaic within the Southern Levant region. Results indicate that despite climatic fluctuations, local micromammal communities persist during the MP throughout the Southern Levant. These results suggest that although hominin taxa show evidence of turnover during the Upper Pleistocene in the Southern Levant, we need to be more cautious about the role of climate-forcing in the process. Acknowledgements: I would like to thank Ofer Bar-Yosef, Iain Davidson, and Mina Evron for valuable suggestions during preparation of the paper. This research was funded by a generous grant from the Irene Levy Sala CARE foundation and the American School of Prehistoric Research (ASPR) postdoctoral fellowship, Harvard University. References Cited: Jelinek, A. 1980. The Middle Paleolithic of the Levant. In: Sanlaville, P. and Cauvin, J. (Eds.), Prehistoire du Levant. Chronologie et Organisation de L’espace depus les origines jusqu’au VIe Millénaire. Éditions du Centre National de la Recherche Scientifique, Paris, pp. 299–304. Jelinek, A.J., Farrand, W.R., Haas, G., Horowitz, A., and Goldberg, P. 1973. New excavations at the Tabun Cave, Mount Carmel, Israel, 1967-1972; A preliminary report. Paléorient 1: 151–183. Shea, J.J. 2008. Transitions or turnovers? Climatically-forced extinctions of Homo sapiens and Neanderthals in the east Mediterranean Levant. Quaternary Science Reviews 27: 2253–2270. Tchernov, E. 1998. The Faunal Sequence of the Southwest Asian Middle Paleolithic in Relation to Hominid Dispersal Events. In: Neandertals and Modern Humans in Western Asia, Akazawa, T., Aoki, K., and Bar-Yosef, O. (Eds.). Plenum Press, New York, pp. 77–90. Variation in holocene Khoesan Dentition Wendy Black, Archaeology, University of Cape Town, SOUTH AFRICA Rebecca Rogers Ackermann, Archaeology, University of Cape Town, SOUTH AFRICA Judith Sealy, Archaeology, University of Cape Town, SOUTH AFRICA There have been many studies of dental variation in Holocene populations of Europe and the Americas, but few of African populations. Dental analyses of the Holocene Khoesan populations of Southern Africa provide insight into the biological evolution of an anthropologically important people. Here, we present results on metric and non-metric dental analyses of this Sub-Saharan African group, including an intensive focus on Early Holocene material. Data were collected from >650 adult Khoesan individuals. When possible, standard dental measurements were taken on all teeth and cervical molar measurements compensated for teeth affected by heavy wear. Qualitative traits were also assessed for the permanent dentition using scoring procedures for key morphological traits, as outlined in the Arizona State University dental anthropology system. Metric data analyses indicate that tooth size fluctuations generally conform to the midto late Holocene size variations observed in other studies of cranial and post-cranial material. Teeth, during this time period, appear to be smaller than Early Holocene counterparts and discernible reductions are identified through most measurements. However, apparent tooth size fluctuations during the Early Holocene are also observed, and while these may coincide with notable climatic changes during this period, sample size constraints make firm conclusions difficult. In contrast, qualitative trait variation appears to be less variable and largely consistent throughout the sample. Although differences in trait frequencies among Southern African populations throughout the last 12,000 years do exist, there is no evidence for unique trait variation in any population, suggesting that population differences result from intrinsic factors affecting the populations, such as environmental and geographic variation, rather than gene flow from outlying areas. Taken together, these results support recent hypotheses of morphological and genetic continuity in Southern African populations during the Holocene. Timing the Appearance of Homo in the Turkana basin René Bobe, Anthropology, University of Georgia, USA Meave Leakey, Anthropology, Stony Brook University, USA Understanding the origin of Homo remains a central problem in paleoanthropology. Significant evidence relevant to this issue derives from the Omo-Turkana Basin of Kenya and Ethiopia. Here we focus on the question of when Homo first appears in the basin and assess the strength of first appearance data (FAD). The data derive from two databases: one for the Kenyan side of the Turkana Basin (16,500 records) and one for the lower Omo valley in Ethiopia (24,000 records). The earliest appearance of Homo is dated to about 2.4 Ma, but this FAD has to be assessed in relation to the abundance of paleontological samples preceding the first occurrence. In the Shungura Formation, Homo appears in Member E, at about 2.4 Ma. Earlier samples in the time range from 2.4 to 3 Ma include 6,244 fossil mammals that have not provided evidence of Homo. Thus, the earliest record of Homo in the Shungura Formation may be close in time to a true origination or migration event. At Koobi Fora the earliest record of Homo derives from the Upper Burgi Member and dates to about 2 Ma. However, at Koobi Fora there is an unconformity below the Upper Burgi Member, and lower strata dating back to 3 Ma provide a sample of only 204 fossil mammals. Thus this FAD has a large margin of error. On the west side of Lake Turkana the earliest specimen attributed to Homo is a molar from the base of the Kalochoro Member dated to about 2.3 Ma. The sample from the Nachukui Formation is small and therefore this FAD at near 2.3 Ma also has a large margin of error. The data discussed here indicate that the critical time period for understanding the origin and dispersal of Homo is between about 3 and 2.4 Ma.