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

Earliest Porotic Hyperostosis on a 1.5-Million-year-old Hominin, olduvai gorge, Tanzania.

Meat-eating was an important factor affecting early hominin brain expansion, social organization and geographic movement. Stone tool butchery marks on ungulate fossils in several African archaeological assemblages demonstrate a significant level of carnivory by Pleistocene hominins, but the discovery at Olduvai Gorge of a child's pathological cranial fragments indicates that some hominins probably experienced scarcity of animal foods during various stages of their life histories. The child's parietal fragments, excavated from 1.5-million-year-old sediments, show porotic hyperostosis, a pathology associated with anemia. Nutritional deficiencies, including anemia, are most common at weaning, when children lose passive immunity received through their mothers' milk. Our results suggest, alternatively, that (1) the developmentally disruptive potential of weaning reached far beyond sedentary Holocene food-producing societies and into the early Pleistocene, or that (2) a hominin mother's meat-deficient diet negatively altered the nutritional content of her breast milk to the extent that her nursing child ultimately died from malnourishment. Either way, this discovery highlights that by at least 1.5 million years ago early human physiology was already adapted to a diet that included the regular consumption of meat

Quaternary fossil horses within the Prados-Guatén Depression (Pantoja de La Sagra, Toledo)

Durante la primera reunión de campo del Grupo Madrileño de Cuaternario (GQM-AEQUA) se localizaron restos fragmentarios de dentición de caballos fósiles en los antiguos areneros de Pantoja de La Sagra (Toledo), actualmente en proceso de desmantelamiento y relleno. Ante la posibilidad de deterioro y pérdida los restos fueron recolectados y trasladados al Museo Nacional de Ciencias Naturales (CSIC, Madrid) donde se ha procedido a su análisis. Las piezas fósiles analizadas responden a un maxilar izquierdo con tres piezas dentales in situ (molares y premolares), y otras siete más aisladas. Todos los dientes aislados, junto con el fragmento de maxilar existente, corresponden a un adulto joven. Los restos fósiles se encontraban asociados a un nivel de arenas fluviales situado unos cuatro metros por debajo de la superficie de la Terraza de +15 m de la Depresión Prados-Guatén definida como un nivel perteneciente al tránsito Pleistoceno inferior-medio, del antiguo Sistema fluvial Manzanares-Guatén por Silva (1988). En concreto los niveles superiores de esta terraza han sido interpretados como resultado de la superposición de los últimos depósitos del antiguo sistema fluvial y los primeros asociados al relleno de la Depresión por tributarios de área fuente más local tras su abandono como consecuencia del proceso de captura del valle inferior del Manzanares por parte del Río Jarama al SW de la Ciudad de Madrid (Silva et al., 1988). Los caracteres morfológicos y morfométricos de las piezas dentarias permiten identificarlos como Equus ferus cf. mosbachensis cuya distribución bioestratigráfica abarca la parte final del Pleistoceno Medio (c.a. 500-200 ka B.P.). Junto a los restos fósiles aparecieron también escasos fragmentos líticos correspondientes a productos de lascado en sílex de difícil atribución tecnológica. Los restos fósiles analizados, indican que el depósito extensivo de arenas fluviales en el eje de la Depresión, culminó durante el final del Pleistoceno medio, y que la dinámica fluvial de la Depresión tras su proceso de abandono fue de hecho más activa de lo que se pensaba con la instalación de sistemas de arroyos relevantes alimentados por cabeceras locales antes del encajamiento definitivo actual de los arroyos Prados y Guatén.During the first field-meeting of the Madrid Quaternary Research Group (GQM-AEQUA) several fossil teeth remnants of horses were localised at the ancient sand-quarries of Pantoja de La Sagra (Toledo), which presently are abandoned and refilling in progress. The possibility of deterioration and loss of the localised fossils remnants induced by the quarry works, they were collected and taken away to the Museo Nacional de Ciencias Naturales (CSIC, Madrid) for their preservation and analysis. Fossil remains correspond to a left maxilla with two in situ molars, another one inset on its alveolar cavity, fragments of premolar cavities, as well as other seven more isolated teeth. These fossils were outcropping in a sandy level at four meters below the +15 m fluvial terrace surface of the axial sector of de Prados-Guatén Depression, which is considered the last fluvial level belonging to the ancient Manzanares-Guatén fluvial system during the Lower-Middle Pleistocene transit (Silva, 1988). In detail, the upper fluvial sediments of this particular terrace level were interpreted as the result of the overlapping between the last materials deposited by the ancient Manzanares-Guatén fluvial system and the first ones resulting from the readjustment of former tributaries after the abandonment of the Depression caused by fluvial capture of the Lower Manzanares Valley SW Madrid City. The morphological features of the oclusal surface of the horse teeth and morphometric comparative analyses indicate that they belong to the specie Equus ferus, and probably to the subspecie mosbachensis. However due to the bad definition of this group in Europe and the few individuals analysed the better classification is Equus ferus cf. mosbachensis. The bioestratigraphic distribution of this fossil horse group in Europe extends on the upper part of the Middle Pleistocene (c.a. 500-200 ka B.P.). Few lithic artefacts outcropped also associated to the fossil remains, constituted by laminar flakes of hard technological classification. Fossil remains analysed in this work joint to the unique previous quaternary fossil mammal described for the Prados-Guatén Depression constituted by Mammuthus meridionalis NESTI of the former quarry of Esquivias adjacent to the AVE railway line (Silva et al., 1988b; 1999). The chronostratigraphic attribution of the fossil horses (Upper Middle Pleistocene) described here indicate that fluvial sedimentary activity within the Depression was relevant after its abandonment. Ancient tributaries of the former Manzanares-Guatén fluvial system, feed by local-intrabasinal headwaters, reworked the previous sandy sediments triggering multiepisodic deposition during the upper part of the Middle Pleistocene, before the more recent eventual incision of present streams dissecting the Depression

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 functionally-associated 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 bifacial 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

Restos de caballos fósiles cuaternarios en la depresión Prados-Guatén (Pantoja de la Sagra, Toledo)

Durante la primera reunión de campo del Grupo Madrileño de Cuaternario (GQM-AEQUA) se localizaron restos fragmentarios de dentición de caballos fósiles en los antiguos areneros de Pantoja de La Sagra (Toledo), actualmente en proceso de desmantelamiento y relleno. Ante la posibilidad de deterioro y pérdida los restos fueron recolectados y trasladados al Museo Nacional de Ciencias Naturales (CSIC, Madrid) donde se ha procedido a su análisis. Las piezas fósiles analizadas responden a un maxilar izquierdo con tres piezas dentales in situ (molares y premolares), y otras siete más aisladas. Todos los dientes aislados, junto con el fragmento de maxilar existente, corresponden a un adulto joven. Los restos fósiles se encontraban asociados a un nivel de arenas fluviales situado unos cuatro metros por debajo de la superficie de la Terraza de +15 m de la Depresión Prados-Guatén definida como un nivel perteneciente al tránsito Pleistoceno inferior-medio, del antiguo Sistema fluvial Manzanares-Guatén por Silva (1988). En concreto los niveles superiores de esta terraza han sido interpretados como resultado de la superposición de los últimos depósitos del antiguo sistema fluvial y los primeros asociados al relleno de la Depresión por tributarios de área fuente más local tras su abandono como consecuencia del proceso de captura del valle inferior del Manzanares por parte del Río Jarama al SW de la Ciudad de Madrid (Silva et al., 1988). Los caracteres morfológicos y morfométricos de las piezas dentarias permiten identificarlos como Equus ferus cf. mosbachensis cuya distribución bioestratigráfica abarca la parte final del Pleistoceno Medio (c.a. 500-200 ka B.P.). Junto a los restos fósiles aparecieron también escasos fragmentos líticos correspondientes a productos de lascado en sílex de difícil atribución tecnológica. Los restos fósiles analizados, indican que el depósito extensivo de arenas fluviales en el eje de la Depresión, culminó durante el final del Pleistoceno medio, y que la dinámica fluvial de la Depresión tras su proceso de abandono fue de hecho más activa de lo que se pensaba con la instalación de sistemas de arroyos relevantes alimentados por cabeceras locales antes del encajamiento definitivo actual de los arroyos Prados y Guatén.Peer reviewe

Microbial biomarkers reveal a hydrothermally active landscape at Olduvai Gorge at the dawn of the Acheulean, 1.7 Ma

Landscape-scale reconstructions of ancient environments within the cradle of humanity may reveal insights into the relationship between early hominins and the changing resources around them. Many studies of Olduvai Gorge during Pliocene–Pleistocene times have revealed the presence of precession-driven wet–dry cycles atop a general aridification trend, though may underestimate the impact of local-scale conditions on early hominins, who likely experienced a varied and more dynamic landscape. Fossil lipid biomarkers from ancient plants and microbes encode information about their surroundings via their molecular structures and composition, and thus can shed light on past environments. Here, we employ fossil lipid biomarkers to study the paleolandscape at Olduvai Gorge at the emergence of the Acheulean technology, 1.7 Ma, through the Lower Augitic Sandstones layer. In the context of the expansion of savanna grasslands, our results represent a resource-rich mosaic ecosystem populated by groundwater-fed rivers, aquatic plants, angiosperm shrublands, and edible plants. Evidence of a geothermally active landscape is reported via an unusual biomarker distribution consistent with the presence of hydrothermal features seen today at Yellowstone National Park. The study of hydrothermalism in ancient settings and its impact on hominin evolution has not been addressed before, although the association of thermal springs in the proximity of archaeological sites documented here can also be found at other localities. The hydrothermal features and resources present at Olduvai Gorge may have allowed early hominins to thermally process edible plants and meat, supporting the possibility of a prefire stage of human evolution

El registro Paleolítico de las terrazas complejas de los valles del Manzanares y Jarama

Peer reviewe