The origin of the Acheulean: the 1.7 million-year-old site of FLK West, Olduvai Gorge (Tanzania)

The appearance of the Acheulean is one of the hallmarks of human evolution. It represents the emergence of a complex behavior, expressed in the recurrent manufacture of large-sized tools, with standardized forms, implying more advance forethought and planning by hominins than those required by the precedent Oldowan technology. The earliest known evidence of this technology dates back to c. 1.7 Ma. and is limited to two sites (Kokiselei [Kenya] and Konso [Ethiopia]), both of which lack fauna. The functionality of these earliest Acheulean assemblages remains unknown. Here we present the discovery of another early Acheulean site also dating to c. 1.7 Ma from Olduvai Gorge. This site provides evidence of the earliest steps in developing the Acheulean technology and is the oldest Acheulean site in which stone tools occur spatially and functionally associated with the exploitation of fauna. Simple and elaborate large-cutting tools (LCT) and handaxes co-exist at FLK West, showing that complex cognition was present from the earliest stages of the Acheulean. Here we provide a detailed technological study and evidence of the use of these tools on the butchery and consumption of fauna, probably by early Homo erectus sensu lato

Geocronología de la Terraza Compleja de Arganda en el valle del río Jarama (Madrid, España)

La Terraza Compleja de Arganda (TCA), situada en el tramo bajo del río Jarama (Madrid), está formada por sucesivos apilamientos de secuencias fluviales denominados de abajo a arriba Arganda I, II, III y IV, en los que se han encontrado importantes yacimientos arqueológicos y paleontológicos del Pleistoceno (Áridos 1 y 2, Valdocarros o HAT), y numerosos conjuntos de industria lítica del Paleolítico inferior y medio. Hasta ahora, la única referencia cronológica disponible para la TCA era la proporcionada por el estadio evolutivo de los micromamíferos de los yacimientos Áridos 1 en Arganda I y Valdocarros en Arganda II. En este trabajo, se propone la equivalencia de las distintas unidades de la TCA con terrazas escalonadas y se establece un marco cronológico numérico, obtenido mediante dataciones de termoluminiscencia, luminiscencia ópticamente estimulada y racemización de aminoácidos. Arganda I (≈ T+30-32 m) se situaría hacia el final del MIS 11 o en el inicio del MIS 9, Arganda II (≈T+23-24 m) se correspondería con el inicio del MIS 7, Arganda III (≈T+18-20 m) se situaría entre el MIS 7 y el MIS 5, y Arganda IV comenzaría su deposición en el MIS 5 finalizando su sedimentación en el MIS 1 al sur de Arganda del Rey (Madrid)

La inversión matuyama-brunhes en la secuencia de terrazas del río Jarama entre Velilla de San Antonio y Altos de la Mejorada, al se de Madrid (España

Al Este de la ciudad de Madrid, en el valle del río Jarama y entre Mejorada del Campo y Velilla de San Antonio se han estudiado las propiedades paleomagnéticas de una secuencia de terrazas comprendidas entre El Rasillo y Altos de la Mejorada, a lo largo de la autopista M-203 de reciente construcción. La car- tografía geomorfológica realizada permitió separar además de la llanura aluvial a +4-5 m, terrazas a +20 m, +30-35 m, +60-65 m, +85-90 m, +105-110 m y +125-130 m. De ellas se muestrearon 5 niveles, a excepción de la de +20 m, en taludes frescos de la autovía que permiten situar a las terrazas con altitudes relativas igual o mayores a +60-65 m en el Chron Matuyama, mientras que las terrazas a +20 m y +30-35 m pertenecerían al Chron Brunhes (< 0.780 Ma). Dataciones por ESR en terrazas del valle del río Arlanzón en Burgos (Moreno et al., 2012), sugieren que en el valle del Jarama la inversión Matuyama-Brunhes podría establecerse entre el final de la sedimentación de la terraza a +60-65 m y el encajamiento de la terraza a +50-55 m subsiguiente, representada aguas arriba de Mejorada del Campo, en Marchamalo (Pérez-González, 1994)

The Acheulean of the Upper Guadiana River Basin (Central Spain). Morphostratigraphic Context and Chronology

In the upper basin of the Guadiana River, especially in the sectors drained by its right-bank tributaries, the Bullaque and Becea rivers, important concentrations of Acheulean and Mousterian industries can be found in a superficial position. These industries have provided series containing tens of thousands of pieces. Deposits in stratigraphic position have also been identified, related to the fluvial terraces of the Guadiana and Jabalón rivers and some tributaries. Within the sector studied, in the province of Ciudad Real, the position of these deposits is related to alluvial fans developed on the slopes of the immediate reliefs. These fans, mainly composed of Lower and Middle Ordovician quartzite gravel, were eroded in their distal positions by the Bullaque and Becea rivers, forming very low terraces on which large concentrations of Acheulean and Mousterian lithic industry can be found. El Sotillo, the only known stratigraphic site in the area, was excavated in 2017–2019 and consists of several levels with Mousterian and Acheulean industry. We present the technological characteristics of the main Acheulean assemblage recognised at this site, for which numerical dates have been obtained placing its chronology in the second half of the Middle Pleistocene. The location of these sites, in surficial position and El Sotillo, allows us to recognise a territorial space with specific geographic characteristics and a very significant human impact.M. Santonja, A. Pérez-González, J. Baena, J. Panera, E. Méndez-Quintas, D. Uribelarrea, M. Demuro, L. Arnold, A. Abrunhosa, and S. Rubio-Jar

Geo-archaeological and geometrically corrected reconstruction of the 1.84 Ma FLK Zinj paleolandscape at Olduvai Gorge, Tanzania

A geomorphological, sedimentological, stratigraphic, and geometric study of 30 trenches excavated around FLK Zinj (Bed I, Olduvai Gorge) has enabled the partial reconstruction of the paleolandscape surrounding this site for a radius of ∼1000 m. This is the largest sample of geological and archaeological information yet available to reconstruct the topography, ecology, and geomorphology of the Zinj paleosurface and the hominin activities preserved within it. Contrary to previous interpretations, which place FLK Zinj on an isolated and narrow peninsula, it appears that the site was located on the edge of an elevated platform traceable for hundreds of meters. Hominins created FLK Zinj (and other sites, such as the recently discovered PTK and AMK) within the wooded habitats of this platform rather than the more open and grassy environments situated on lower portions of the lacustrine floodplain. Input areas, probably in the form of alluvial fans, existed to the south, following a North-South direction. These input areas are partially responsible for changes in the type sequence. Restricted erosion documented on the wooded platform was mostly caused by runoff processes. An archaeological study of the excavated trenches reveals a sharp contrast in fossil and stone tool density between FLK Zinj and the surrounding landscape, further supporting the contention that the site may have acted as a “central place” where repeated carcass transport, butchery, and consumption took place. Taphonomic studies indicate that at this stage of human evolution, hominins had primary access to carcasses and were not dependent on other carnivores for obtaining meat

The paleoecology and taphonomy of AMK (Bed I, Olduvai Gorge) and its contributions to the understanding of the “Zinj” paleolandscape

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