Australopithecus africanus

P r F r e d e r i c k GRI NE P r B r u n o MA URE I L L E P r F r é d é r i c V A Y S S E 1 2 / 0 9 / 2 0 1 6 Acknowledgement I would like to express my deepest appreciation to the supervisor of my doctoral studies, Professor Jos é Braga, at the Laboratoire d'Anthropologie Molé culaire et Imagerie de Synthè se, not only for accepting me as a PhD student three years ago, but for his continuous support throughout my doctoral study. He kindly provided me with many opportunities to participate in research projects, fieldwork and collaborations. His enthusiasm, persistance and dedication in research have a deep influence on me and my future academic career. Jean Dumoncel, our engineer and technician, particularly assisted me during my doctoral studies, he helped me with the geometric morphometric analyses I employed in this thesis. He kindly taught me how to use the programs he developed, patiently helped me when I encountered difficulties with the statistical analyses. I would like to thank Clé ment Zanolli, for including me in his research projects, for providing micro-CT data of modern humans and Neanderthals, Clé ment and I also had many fruitful discussions on the study sample, the interpretations of the results, and on my career choice. I thank Amé lie Beaudet for helping me with principals of enamel thickness measurements and geometric morphometrics, and she was always there when I had difficulties with the French language and administrations. I would like to express my gratitude to these colleagues and instututions which helped with the micro -CT scans and data collection: Firkkie de Beer and Jakobus Hoffman (South African Nuclear Energy Corporation), Benjamin Duployer and Christophe Tenailleau (UMR 5085 CNRS), Song Xing (IVPP); for the permissions and assistance to study the materials, I thank Francis Thackeray (Wits University), Stephany Potze (Ditsong National Museum of Natural History), Anna Oettlé (University of Pretoria) and Catherine Thè ves (UM R 5288 CNRS). Also, I would like to especially thank Francis for his kind support when I tried t o apply for a post-doc position. During my doctoral studies I was fortunate to receive valuable support from many senior scholars, I thank Roberto Macchiarelli for his insights on the Neanderthal taxonomy and chronology; Maria Martinón-Torres for her kind acceptance of collaboration; Wu Liu and Xiujie Wu for information on Chinese fossil hominins and for their advice on pursuing a career; Laurent Bruxelles for his interpretation of the Kromdraai stratigraphy and Sterkfontein cave systems. I deeply appreciate the reviewers of my doctoral dissertation for their efforts to improve the quality of the manuscript, I will benefit from their valuable comments and suggestions during my future academic career.

The importance of diet in primate ecology has motivated the use of a variety of methods to reconstruct dietary habits of extinct hominin taxa. Dental microwear is one such approach that preserves evidence from consumed food items. This study is based on 44 specimens of Australopithecus africanus from Makapansgat and Sterkfontein, and 66 specimens of Paranthropus robustus from Swartkrans, Kromdraai and Drimolen. These samples enable examination of potential differences between the two assemblages of A. africanus, and among the various assemblages of P. robustus in relation to the paleoenvironmental reconstructions that have been proffered for each fossil site. Sixteen microwear texture variables were recorded for each specimen from digital elevation models generated using a white-light confocal profiler. Only two of these differ significantly between the Makapansgat and Sterkfontein samples of A. africanus. None of the microwear texture variables differs significantly among the samples of P. robustus. On the other hand, P. robustus has significantly higher values than A. africanus for 11 variables related to feature complexity, size, and depth; P. robustus exhibits rougher surfaces that comprise larger, deeper features. In contrast, A. africanus has smoother, simpler wear surfaces with smaller, shallower and more anisotropic features. As for possible habitat differences among the various sites, only a relatively small number of subtle differences are evident between the specimens of A. africanus from Makapansgat and Sterkfontein, and there are none among the specimens of P. robustus from various deposits. As such, it is reasonable to conclude that, while subtle differences in microwear textures may reflect differences in background habitats, the wear fabric differences between P. robustus and A. africanus are most reasonably interpreted as having been driven by dietary differences.

Ever since Tyson (1699), anatomists have noted and compared differences in the regional numbers of vertebrae among humans and other hominoids. Subsequent workers interpreted these differences in phylogenetic, functional, and behavioral frameworks and speculated on the history of vertebral numbers during human evolution. Even in a modern phylogenetic framework and with greatly expanded sample sizes of hominoid species, researchers' conclusions vary drastically, positing that hominins evolved from either a " long-backed " (numerically long lumbar column) or a " short-backed " (numerically short lumbar column) ancestor. We show that these disparate interpretations are due in part to the use of different criteria for what defines a lumbar vertebra, but argue that, regardless of which lumbar definition is used, hominins are similar to their great ape relatives in possessing a short trunk, a rare occurrence in mammals and one that defines the clade Hominoidea. Furthermore, we address the recent claim that the early hominin thoracolumbar configuration is not distinct from that of modern humans and conclude that early hom-inins show evidence of " cranial shifting, " which might explain the anomalous morphology of several early hominin fossils. Finally, we evaluate the competing hypotheses on numbers of vertebrae and argue that the current data support a hominin ancestor with an African ape-like short trunk and lower back. Am J Phys Anthropol 159:S19–S36, 2016. V C 2016 Wiley Periodicals, Inc.

Many antelopes have an excellent sense of smell, and our human relatives such as Paranthropus robustus may have associate themselves with those antelope species during the day to avoid predation by lions, leopards and carnivores. This helps to explain why robust australopithecines successfully survived for nearly a million years on the Highveld of South Africa.

Estimation of endocranial volume in Australopithecus africanus is important in interpreting early hominin brain evolution. However, the number of individuals available for investigation is limited and most of these fossils are, to some degree, incomplete and/or distorted. Uncertainties of the required reconstruction ('missing data uncertainty') and the small sample size ('small sample uncertainty') both potentially bias estimates of the average and within-group variation of endocranial volume in A. africanus.

First ribs – the first or most superior ribs in the thorax – are rare in the hominin fossil record, and when found, have the potential to provide information regarding the upper thorax shape of extinct hominins. Here, we describe a partial first rib from Member 4 of the Sterkfontein Caves, South Africa. The rib shaft is broken away, so only the head and neck are preserved. The rib is small, falling closest to small-bodied Australopithecus first ribs (AL 288-1 and MH1). Given that it was recovered near the StW 318 femur excavation, which also represents a small individual, we suggest that the two may be associated. Three-dimensional geometric morphometric analyses were used to quantify the rib fragment morphology and compare it to extant hominoid and other fossil hominin ribs. While only the proximal end is preserved, our analyses show that South African Australopithecus share derived features of the proximal first rib more closely resembling A. afarensis and later hominins than grea...

The relatively small Australopithecus africanus specimen Sts 5 has figured prominently in taxonomic debates, and the determination of this specimen as a young male or an elderly female has the potential to offer a great deal of resolution on this question. Sts 5 has been argued to be either a small, immature male or a mature female based on a variety of characters.

Deux bassins (STS 14, AL 288) et cinq os coxaux d'Australopithèques (SK 50, SK 3155. MLD 7), ainsi qu'un os coxal de Homo erectus (OH 28) ont été étudiés biométriquement à l'aide d'un programme d'analyse des correspondances, en comparaison avec la totalité des Simiens catarrhiniens (367 individus adultes appartenant à 19 genres). 16 mesures ont été prises sur le bassin, dont 11 sur l'os coxal seul. Les Australopithèques forment un groupe de Bipèdes avec le genre Homo (H. sapiens + H. erectus) qui s'oppose au groupe des Brachiateurs (Pongidés et Hylobatidés). Deux groupes d'Australopithèques peuvent être distingués: l'un est formé par A . robustus, plus spécialisé et éloigné du genre Homo (autre type de spécialisation bipède), l'autre est formé par A.afarensis + A. africanus, moins spécialisés et plus proches de l'origine humaine.

The fossilized primate skull known as the Taungs Baby, discovered in South Africa, was put forward in 1925 as a controversial 'missing link' between humans and apes. This essay examines the controversy generated by the fossil, with a focus on practice and the circulation of material objects. Viewing the Taungs story from this perspective provides a new outlook on debates, one that suggests that attention to the importance of place, particularly the ways that specific localities shape scientific practices, is crucial to understanding such controversies. During the 1920s, the fossil itself did not move or circulate from its South African location, a fact that raised methodological concerns in understanding its significance and drew immense criticism from a range of experts. Examining the criticisms regarding the fossil's failure to circulate draws attention to the importance of centers of accumulation in the analysis of hominid fossils. Diverging from existing histories that primarily emphasize the role of theory in paleoanthropological debates, then, this article argues that scientific practice played an important role in the Taungs fossil controversy. Examining this dimension of the debates has broader implications for revealing the underlying imperial assumptions that guided hominid paleontology during the early twentieth century.

This study quantifies the metacarpal 1 (MC 1) proximal articular surface using three-dimensional morphometrics in extant hominids and fossil hominins (SK 84, cf. Paranthropus robustus/Homo erectus and StW 418, Australopithecus africanus) to understand which characteristics of the proximal metacarpal 1 are potentially correlated with human manipulative abilities and if they can be used in a paleoanthropological setting. A principal components (PC) analysis was used to compare MC 1 proximal articular surface shape and ANOVA and Tukey’s HSD post hoc tests were conducted to determine differences among groups. Homo is significantly different from nonhuman hominids having a less radioulnarly and dorsovolarly curved articular surface. All nonhuman hominids have more curved articular surface with Gorilla showing the most curved joint. Moreover, this study highlights the presence of a radially extended surface in Homo that may be related to the greater thumb abduction in human manipulation activities. Both fossils analyzed show a great ape-like MC 1 proximal articular surface which, associated with recent trabecular and archaeological evidence, may indicate that the ability to make/use stone tools preceded the morphological adaptations associated today to such behavior.

Distinctive expressions and incidences of discrete dental traits at the outer enamel surface (OES) contribute to the diagnoses of many early hominin taxa. Examination of the enamel-dentine junction (EDJ), imaged non-destructively using micro-computed tomography, has elucidated the morphological development of dental traits and improved interpretations of their variability within and among taxa. The OES expressions of one of these dental traits, the protostylid, have been found to differ among African Plio-Pleistocene fossil hominin taxa. In this study protostylid expression is examined at the OES and at the EDJ of Paranthropus robustus (n ¼ 23) and Australopithecus africanus (n ¼ 28) mandibular molars, with the goals of incorporating EDJ morphology into the definition of the protostylid and assessing the relative contribution of the EDJ and enamel cap to its expression in these taxa. The results provide evidence a) of statistically significant taxon-specific patterns of protostylid morphology at the EDJ that are not evident at the OES; b) that in P. robustus, thick enamel reduces the morphological correspondence between the form of the protostylid seen at the EDJ and the OES, and c) that if EDJ images can be obtained, then the protostylid retains its taxonomic value even in worn teeth.