Zeresenay Alemseged

Evidence for stone-tool-assisted consumption of animal tissues before 3.39 million years ago at Dikika, Ethiopia

The oldest direct evidence of stone tool manufacture comes from Gona (Ethiopia) and dates to between 2.6 and 2.5 million years (Myr) ago. At the nearby Bouri site several cut-marked bones also show stone tool use approximately 2.5u2009Myr ago. Here we report stone-tool-inflicted marks on bones found during recent survey work in Dikika, Ethiopia, a research area close to Gona and Bouri. On the basis of low-power microscopic and environmental scanning electron microscope observations, these bones show unambiguous stone-tool cut marks for flesh removal and percussion marks for marrow access. The bones derive from the Sidi Hakoma Member of the Hadar Formation. Established 40Ar–39Ar dates on the tuffs that bracket this member constrain the finds to between 3.42 and 3.24u2009Myr ago, and stratigraphic scaling between these units and other geological evidence indicate that they are older than 3.39u2009Myr ago. Our discovery extends by approximately 800,000 years the antiquity of stone tools and of stone-tool-assisted consumption of ungulates by hominins; furthermore, this behaviour can now be attributed to Australopithecus afarensis.

A juvenile early hominin skeleton from Dikika, Ethiopia

Understanding changes in ontogenetic development is central to the study of human evolution. With the exception of Neanderthals, the growth patterns of fossil hominins have not been studied comprehensively because the fossil record currently lacks specimens that document both cranial and postcranial development at young ontogenetic stages. Here we describe a well-preserved 3.3-million-year-old juvenile partial skeleton of Australopithecus afarensis discovered in the Dikika research area of Ethiopia. The skull of the approximately three-year-old presumed female shows that most features diagnostic of the species are evident even at this early stage of development. The find includes many previously unknown skeletal elements from the Pliocene hominin record, including a hyoid bone that has a typical African ape morphology. The foot and other evidence from the lower limb provide clear evidence for bipedal locomotion, but the gorilla-like scapula and long and curved manual phalanges raise new questions about the importance of arboreal behaviour in the A. afarensis locomotor repertoire.

Hominin Environments in the East African Pliocene: An Assessment of the Faunal Evidence

1. Approaches to the analysis of faunal change during the East African Pliocene Anna K. Behrensmeyer, Rene Bobe, Zeresenay Alemseged 2. Environmental hypotheses of Pliocene human evolution Richard Potts 3. African Pliocene and Pleistocene cercopithecid evolution and global climatic change Stephen R. Frost 4. Patterns of change in the Plio-Pleistocene carnivorans of eastern Africa: implications for hominin evolution Margaret E. Lewis, Lars Werdelin 5. Stratigraphic variation in Suidae from the Shungura Formation and some coeval deposits H.B.S. Cooke 6. Patterns of abundance and diversity in late Cenozoic bovids from the Turkana and Hadar Basins, Kenya and Ethiopia Rene Bobe, Anna K. Behrensmeyer, Gerald G. Eck, John M. Harris 7. Comparability of fossil data and its significance for the interpretation of hominin envrironments: a case study in the lower Omo Valley, Ethiopia Zeresenay Alemseged, Rene Bobe, Denis Geraads 8. The effects of collection strategy and effort on faunal recovery: a case study of the American and French collections from the Shungura Formation, Ethiopia Gerald G. Eck 9. Serengeti micromammals and their implications for Olduvai paleoenvironments Denne N. Reed 10. Taphonomy and paleoecological context of the Upper Laetolil Beds (Localities 8 and 9), Laetoli in northern Tanzania Charles Musiba, Cassian Magori, Melissa Stoller, Tamara Stein, Scott Branting, Mike Vogt, Russell Tuttle, Benedikt Hallgrimsson, Saidi Killindo, Ferdinand Mizambwa, Felix Ndunguru, Audax Mabulla 11. The paleoecology of the Upper Laetolil Beds at Laetoli: a reconsideration of the large mammal evidence Denise Su, Terry Harrison 12. Fauna, taphonomy and ecology of the Plio-Pleistocene Chiwondo Beds,Northern Malawi Oliver Sandrock, Ottmar Kullmer, Friedemann Schrenk, Y. M. Juwayeyi, Tim Bromage Finale and future: investigating faunal evidence for hominin paleoecology in East Africa Anna K. Behrensmeyer, Zeresenay Alemseged, Rene Bobe

An integrated approach to taphonomy and faunal change in the Shungura Formation (Ethiopia) and its implication for hominid evolution

Environmental and faunal changes through time have been recorded for many African Plio-Pleistocene sites. Fossil evidence suggests that there is a continuous, if not uniform, transformation of the fauna and flora from the Pliocene through the end of Pleistocene. However, discerning major biotic turnovers and linking them to global and regional climatic changes have been complicated by many factors, notably taphonomy and discontinuity of the fossil evidence, notwithstanding the considerable work of some researchers (e.g., Vrba, E.S., 1988. Late Pliocene climatic events and hominid evolution, in: Grine, F. (Ed.), Evolutionary History of the Robust Australopithecines. De Gruyter, New York, pp. 405-426, Vrba, E.S., 1995. The fossil record of African (Mammalia, Bovidae) in relation to human evolution and paleoclimate, in: Vrba, E.S., Denton, G.H., Partridge, T.C., Burkle, L.H. (Eds.), Paleoclimate and Evolution, with Emphasis on Human Origins. Yale University Press, New Haven, pp. 385-424). A sample of over 22,000 fossils collected by the French Omo Expedition, from the Shungura Formation of Ethiopia, was analyzed using an integrated approach to investigate taphonomic and faunal change patterns. The following results are obtained: (1) Univariate and multivariate studies support continuous faunal change from Member A through Member G of the Shungura sequence; (2) Correspondence analysis (CA) on extant bovids in African game parks shows that bovid tribes and genera are generally characterized by habitat specificity; (3) Taphonomic studies demonstrate that the relative abundance of different skeletal elements varies according to depositional environment; (4) CA on 73 localities of the Shungura Formation and 19 mammalian taxa points to a major faunal change around the base of Member G dated to ca. 2.3 Ma. This transformation is characterized by a change to open and edaphic grassland as a dominant type of environment; (5) This major faunal change correlates in time with the appearance of A. boisei. It is tentatively suggested that this major biome change is associated with an anagenetic speciation from A. aethiopicus to A. boisei.

Geological and palaeontological context of a Pliocene juvenile hominin at Dikika, Ethiopia

Since 1999, the Dikika Research Project (DRP; initiated by Z.A.) has conducted surveys and excavations in badlands that expose Pliocene and Pleistocene sediments south of the Awash River in Ethiopia, between surrounding hominin localities at Hadar, Gona and the Middle Awash region. Here we report our geological mapping and stratigraphic measurement of the DRP area, and the context of a remarkably well-preserved skeleton of the earliest known juvenile hominin at the Dikika DIK-1 locality. Our mapping of the DRP area permits a complete definition of the hominin-bearing Hadar Formation and provides a cohesive structural and tectonic framework defining its relationships to adjacent strata. Our findings reveal the basin-scale tectonic, depositional and palaeoenvironmental history of the area, as well as a clear taphonomic and palaeontological context for the juvenile hominin. Such data are crucial for understanding the environmental context of human evolution, and can be integrated into larger-scale tectonic and palaeoenvironmental studies. Our basin-scale approach to palaeoenvironments provides a means to elucidate the complex geological history occurring at the scale of temporally and geographically controlled fossil point localities, which occur within the rich tectonic and depositional history of the Awash Valley.

Tool-marked bones from before the Oldowan change the paradigm

Dominguez-Rodrigo et al. (1) critiqued our paper (2), which provided the earliest evidence for stone tool use and animal tissue consumption as evidenced by bones bearing tool-induced marks found at DIK-55 (Dikika, Ethiopia) and dated to 3.39 Ma. Applying a configurational approach, they questioned the bones’ context and without examining or conducting new analysis on the original fossils, argued that all of the Dikika marks resulted from trampling, because a small subset of these marks superficially resembled a small subset of experimentally trampled specimens. Furthermore, they argued (1) that stone tool use and meat consumption before the current consensus dates requires finding manufactured … nn[↵][1]1To whom correspondence should be addressed. E-mail: mcpherron{at}eva.mpg.de.nn [1]: #xref-corresp-1-1

A new Middle Pleistocene fauna from the Busidima-Telalak region of the Afar, Ethiopia

We report on a diverse fauna from the Busidima-Telalak region of the Afar in Ethiopia. The fossiliferous sediments are characterized by river bank deposits. During our first field season thirty one mammalian species were encountered. Fossils are nicely preserved and abundant. Bovids, carnivores, monkeys, and large rodents are the most common taxa. The fauna points to a Middle Pleistocene age (0.2 to 0.8 Ma). Our preliminary paleoenvironmental reconstruction indicates that our fossil assemblage is derived from a rather wet and closed environment. This condition is unique as sites of this time period were reported to be more open and dry.

Approaches to the analysis of faunal change during the East African Pliocene

Vertebrate faunas provide important evidence for the ecological context of evolving hominins over a wide range of scales, from site-specific analysis of taxa directly associated with hominin fossils to faunal trends indicating longterm environmental change that could have affected human evolution. The foundation for all such paleoecological interpretations consists of fossil specimens in their original geological context. Study of fossils in context generates a body of “first-order” evidence consisting of taxonomic identifications of specimens and placement of these taxa in a time/space continuum. Analysis of first-order faunal data in light of additional evidence about taphonomy, sedimentology, geochemistry, and ecomorphology generates a body of “second-order” interpretations. These require additional assumptions and result in evidence for the ecological attributes of a taxon, its habitat, and its temporal and spatial relationships to other taxa. Both firstand second-order data sets can be examined for larger-scale patterns across space and through time. The validity of inferences relating faunal evidence to the ecology of a hominin species requires an additional step, i.e., careful consideration of exactly how the faunal information relates spatially and temporally to hominin remains and archeological sites. Examples of different approaches to using faunal information to infer paleoenvironmental contexts, paleoecological relationships, and long-term ecological trends highlight major issues in faunal analysis and how these relate to understanding the ecological context of human evolution. 2 A.K. BEHRENSMEYER ET AL.