René Bobe

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 2.5 Myr 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 3.24 Myr ago, and stratigraphic scaling between these units and other geological evidence indicate that they are older than 3.39 Myr 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.

Responses of African bovids to Pliocene climatic change

Abstract The record of fossil mammals from the Shungura Formation, lower Omo Valley of southern Ethiopia, represents one of the largest and most carefully controlled samples for deciphering the responses of land faunas to global-scale climatic change. We use the abundant and continuous fossil record of the family Bovidae to analyze the effects of a late Pliocene climatic shift toward increased aridity in Africa beginning at 2.8 Ma and intensifying at about 2.4 Ma. A database consisting of 4233 specimen-based records collected under well-defined procedures is used to define patterns through time in bovid abundances while also controlling for taphonomic and other potential biases. Univariate and multidimensional (correspondence analysis) methods are used to study changes in bovid abundances through time. Our results indicate that bovids experienced an increase in species richness and a rapid episode of change in taxonomic abundances at 2.8 ± 0.1 Ma (between Members B and C), and that this shift was followed by gradual and prolonged changes in abundance between 2.8 and 2.0 Ma (between Member C and upper Member G). An analysis of skeletal-element abundances through the Shungura sequence shows that only moderate changes in taphonomic conditions occurred between 3.0 and 2.1 Ma, when the lower Omo Valley was dominated by a large, meandering river, but that significant changes in the mode of preservation accompanied the onset of lacustrine depositional environments at 2.1 Ma (between lower and upper Member G). A juxtaposition of taxonomic with taphonomic patterns shows that the shift in taxonomic abundances at 2.8 Ma occurred in the absence of significant changes in taphonomic conditions. The main changes in bovid relative abundances and diversity appear to have been driven by broad environmental and climatic changes in Africa. As environmental indicators, bovids show a transition in the Omo at about 2.8 Ma from closed and wet environments in Member B to closed but dry environments in Member C. This drying trend intensified in Members D, E, and F, between about 2.5 and 2.3 Ma. In lower Member G, between 2.3 and 2.1 Ma, there was an increase in bovid abundance and diversity, which may be a result of greater environmental heterogeneity. The pattern of environmental change depicted by Shungura bovids is consistent with independently derived evidence of Omo paleoenvironments (from paleosols, paleoflora, and micromammals), and with regional and global evidence of climatic changes, especially acute between 2.8 and 2.3 Ma, that caused the initiation of glacial cycles in the north and drier climate in the tropics of Africa. Even though the Omo bovids showed distinct responses to large-scale climatic and environmental change, the Omo bovid community also had important attributes of long-term stability: two species, Aepyceros shungurae and Tragelaphus nakuae, dominated the community for nearly one million years. This study highlights the importance of carefully controlled collection procedures of fossil vertebrates and provides an important demonstration of the potential complexity in mode and rate of responses of land faunas to climatic change.

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

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.

Apes in the Anthropocene: flexibility and survival

We are in a new epoch, the Anthropocene, and research into our closest living relatives, the great apes, must keep pace with the rate that our species is driving change. While a goal of many studies is to understand how great apes behave in natural contexts, the impact of human activities must increasingly be taken into account. This is both a challenge and an opportunity, which can importantly inform research in three diverse fields: cognition, human evolution, and conservation. No long-term great ape research site is wholly unaffected by human influence, but research at those that are especially affected by human activity is particularly important for ensuring that our great ape kin survive the Anthropocene.

Taphonomy of fossils from the hominin-bearing deposits at Dikika, Ethiopia

Two fossil specimens from the DIK-55 locality in the Hadar Formation at Dikika, Ethiopia, are contemporaneous with the earliest documented stone tools, and they collectively bear twelve marks interpreted to be characteristic of stone tool butchery damage. An alternative interpretation of the marks has been that they were caused by trampling animals and do not provide evidence of stone tool use or large ungulate exploitation by Australopithecus-grade hominins. Thus, resolving which agents created marks on fossils in deposits from Dikika is an essential step in understanding the ecological and taphonomic contexts of the hominin-bearing deposits in this region and establishing their relevance for investigations of the earliest stone tool use. This paper presents results of microscopic scrutiny of all non-hominin fossils collected from the Hadar Formation at Dikika, including additional fossils from DIK-55, and describes in detail seven assemblages from sieved surface sediment samples. The study is the first taphonomic description of Pliocene fossil assemblages from open-air deposits in Africa that were collected without using only methods that emphasize the selective retention of taxonomically-informative specimens. The sieved assemblages show distinctive differences in faunal representation and taphonomic modifications that suggest they sample a range of depositional environments in the Pliocene Hadar Lake Basin, and have implications for how landscape-based taphonomy can be used to infer past microhabitats. The surface modification data show that no marks on any other fossils resemble in size or shape those on the two specimens from DIK-55 that were interpreted to bear stone tool inflicted damage. A large sample of marks from the sieved collections has characteristics that match modern trampling damage, but these marks are significantly smaller than those on the DIK-55 specimens and have different suites of characteristics. Most are not visible without magnification. The data show that the DIK-55 marks are outliers amongst bone surface damage in the Dikika area, and that trampling is not the most parsimonious interpretation of their origin.

Fossil Mammals and Paleoenvironments in the Omo-Turkana Basin

Although best known for its fossil hominins, the Omo‐Turkana Basin of Kenya and Ethiopia is the source of one of the best records of vertebrate evolution from the Late Cenozoic of Africa. Located near the heart of the East African Rift Valley, the basin serves as an important frame of reference for the continent. The fossil record from this region plays a key role in our efforts to understand the environmental and ecological context of human evolution in Africa. The Omo‐Turkana faunal data shed light on key questions of human evolution: What kinds of environments did early humans inhabit? How did these environments change over time? What is the relationship between faunal change in East Africa and broader patterns of climatic change?

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 … [↵][1]1To whom correspondence should be addressed. E-mail: mcpherron{at}eva.mpg.de. [1]: #xref-corresp-1-1

Pliocene Bovidae (Mammalia) from the Hadar Formation of Hadar and Ledi-Geraru, Lower Awash, Ethiopia

ABSTRACT We revise here the entire collection of Bovidae from the Pliocene Hadar Formation collected at Hadar and Ledi-Geraru, Lower Awash, Ethiopia. Some additions are provided to previously published descriptions, and other forms are described. The complete list includes 28 species, but is dominated by a new species of impala, Aepyceros datoadeni, a kob that we assign to Kobus oricornus, although it belongs to a type distinct from the Omo one, a lineage of alcelaphins that is poorly known elsewhere, Damalborea, and the bovin Ugandax. We also describe a new gazelle, Gazella harmonae, with very peculiar features, including long spiraled horn cores. Changes in the bovid fauna can be detected both within individual lineages, and in the composition of the assemblage. Impala and bovins far outnumber the reduncins in the lower part of the sequence (Basal and Sidi Hakoma members, from ca. 3.8 to 3.2 Ma), but relative abundances become more equal higher up. Biometric changes do occur in the Ugandax and Aepyceros lineages, but are not significant in other lineages. The major evolutionary events occur in the KH1 or KH1/KH2 transition, ca 3.1–3.0 Ma, with appearance of a third tragelaphin species, of a very small alcelaphin and of a large Aepyceros, and the likely disappearance of K. oricornus.