Acheulean Technology Research Articles

Large mammal diets and paleoecology across the Oldowan–Acheulean transition at Olduvai Gorge, Tanzania from stable isotope and tooth wear analyses

The well-dated Pleistocene sediments at Olduvai Gorge have yielded a rich record of hominin fossils, stone tools, and vertebrate faunal remains that, taken together, provide insight to hominin behavior and paleoecology. Since 2008, the Olduvai Geochronology and Archaeology Project (OGAP) has undertaken extensive excavations in Bed II that have yielded a large collection of early Pleistocene stone tools and fossils. The strata of Lower, Middle and Upper Bed II at Olduvai Gorge capture the critical transition from Oldowan to Acheulean technology and therefore provide an opportunity to explore the possible role of biotic and abiotic change during the transition. Here, we analyze newly discovered and existing fossil teeth from Bed II sites using stable isotope and tooth wear methods to investigate the diets of large mammals. We reconstruct the dietary ecology of Bed II mammals and evaluate whether vegetation or hydroclimate shifts are associated with the technological change. Combined isotope and tooth wear data suggest most mammals were C4 grazers or mixed feeders. Carbon isotope data from bulk enamel samples indicate that a large majority of Bed II large mammals analyzed had diets comprising mostly C4 vegetation (>75% of diet), whereas only a small number of individuals had either mixed C3–C4 or mostly C3 diets (<25% C4). Mesowear generally indicates an increase of the abrasiveness of the diet between intervals IIA and IIB (∼1.66 Ma), probably reflecting increased grazing. Microwear indicates more abrasive diets in interval IIA suggesting stronger seasonal differences at the time of death during this interval. This is also supported by the intratooth isotope profiles from Equus oldowayensis molars, which suggest a possible decrease in seasonality across the transition. Neither stable isotope nor tooth wear analyses indicate major vegetation or hydrological change across the Oldowan–Acheulean transition.

Bed II Sequence Stratigraphic context of EF-HR and HWK EE archaeological sites, and the Oldowan/Acheulean succession at Olduvai Gorge, Tanzania

Archaeological excavations at EF-HR and HWK EE allow reassessment of Bed II stratigraphy within the Junction Area and eastern Olduvai Gorge. Application of Sequence Stratigraphic methods provides a time-stratigraphic framework enabling correlation of sedimentary units across facies boundaries, applicable even in those areas where conventional timelines, such as tephrostratigraphic markers, are absent, eroded, or reworked. Sequence Stratigraphically, Bed II subdivides into five major Sequences 1 to 5, all floored by major disconformities that incise deeply into the underlying succession, proving that simple "layer cake" stratigraphy is inappropriate. Previous establishment of the Lemuta Member has invalidated the use of Tuff IIA as the boundary between Lower and Middle Bed II, now redefined at the disconformity between Sequences 2 and 3, a lithostratigraphic contact underlying the succession containing the Lower, Middle, and Upper Augitic Sandstones. HWK EE site records Oldowan technology in the Lower Augitic Sandstone at the base of Sequence 3, within Middle Bed II. We suggest placement of recently reported Acheulean levels at FLK W within the Middle Augitic Sandstone, thus emphasizing that handaxes are yet to be found in earlier stratigraphic units of the Olduvai sequence. This would place a boundary between the Oldowan and Acheulean technologies at Olduvai in the Tuff IIB zone or earliest Middle Augitic Sandstone. A major disconformity between Sequences 3 and 4 at and near EF-HR cuts through the level of Tuff IIC, placing the main Acheulean EF-HR assemblage at the base of Sequence 4, within Upper rather than Middle Bed II. Sequence stratigraphic methods also yield a more highly resolved Bed II stratigraphic framework. Backwall and sidewall surveying of archaeological trenches at EF-HR and HWK EE permits definition of “Lake-parasequences” nested within the major Sequences that record downcutting of disconformities associated with lake regression, then sedimentation associated with lake transgression, capped finally by another erosional disconformity or hiatal paraconformity caused by the next lake withdrawal. On a relative time-scale rather than a vertical metre scale, the resulting Wheeler diagram framework provides a basis for recognizing time-equivalent depositional episodes and the position of time gaps at various scales. Relative timing of archaeological assemblage levels can then be differentiated at a millennial scale within this framework.

The Middle Stone Age in Africa

Paleoanthropology The Olorgesailie basin in the southern Kenya rift valley contains sediments dating back to 1.2 million years ago, preserving a long archaeological record of human activity and environmental conditions. Three papers present the oldest East African evidence of the Middle Stone Age (MSA) and elucidate the system of technology and behavior associated with the origin of Homo sapiens . Potts et al. present evidence for the demise of Acheulean technology that preceded the MSA and describe variations in late Acheulean hominin behavior that anticipate MSA characteristics. The transition to the MSA was accompanied by turnover of large mammals and large-scale landscape change. Brooks et al. establish that ∼320,000 to 305,000 years ago, the populations in eastern Africa underwent a technological shift upon procurement of distantly sourced obsidian for toolmaking, indicating the early development of social exchange. Deino et al. provide the chronological underpinning for these discoveries. Science , this issue p. [86][1], p. [90][2], p. [95][3] [1]: /lookup/doi/10.1126/science.aao2200 [2]: /lookup/doi/10.1126/science.aao2646 [3]: /lookup/doi/10.1126/science.aao2216

Environmental dynamics during the onset of the Middle Stone Age in eastern Africa.

Development of the African Middle Stone Age (MSA) before 300,000 years ago raises the question of how environmental change influenced the evolution of behaviors characteristic of early Homo sapiens We used temporally well-constrained sedimentological and paleoenvironmental data to investigate environmental dynamics before and after the appearance of the early MSA in the Olorgesailie basin, Kenya. In contrast to the Acheulean archeological record in the same basin, MSA sites are associated with a markedly different faunal community, more pronounced erosion-deposition cycles, tectonic activity, and enhanced wet-dry variability. Aspects of Acheulean technology in this region imply that, as early as 615,000 years ago, greater stone material selectivity and wider resource procurement coincided with an increased pace of land-lake fluctuation, potentially anticipating the adaptability of MSA hominins.

Long-distance stone transport and pigment use in the earliest Middle Stone Age.

Previous research suggests that the complex symbolic, technological, and socioeconomic behaviors that typify Homo sapiens had roots in the middle Pleistocene <200,000 years ago, but data bearing on human behavioral origins are limited. We present a series of excavated Middle Stone Age sites from the Olorgesailie basin, southern Kenya, dating from ≥295,000 to ~320,000 years ago by argon-40/argon-39 and uranium-series methods. Hominins at these sites made prepared cores and points, exploited iron-rich rocks to obtain red pigment, and procured stone tool materials from ≥25- to 50-kilometer distances. Associated fauna suggests a broad resource strategy that included large and small prey. These practices imply notable changes in how individuals and groups related to the landscape and to one another and provide documentation relevant to human social and cognitive evolution.

Chronology of the Acheulean to Middle Stone Age transition in eastern Africa

The origin of the Middle Stone Age (MSA) marks the transition from a highly persistent mode of stone toolmaking, the Acheulean, to a period of increasing technological innovation and cultural indicators associated with the evolution of Homo sapiens We used argon-40/argon-39 and uranium-series dating to calibrate the chronology of Acheulean and early MSA artifact-rich sedimentary deposits in the Olorgesailie basin, southern Kenya rift. We determined the age of late Acheulean tool assemblages from 615,000 to 499,000 years ago, after which a large technological and faunal transition occurred, with a definitive MSA lacking Acheulean elements beginning most likely by ~320,000 years ago, but at least by 305,000 years ago. These results establish the oldest repository of MSA artifacts in eastern Africa.

Paleoecology of the Serengeti during the Oldowan-Acheulean transition at Olduvai Gorge, Tanzania: The mammal and fish evidence

Eight years of excavation work by the Olduvai Geochronology and Archaeology Project (OGAP) has produced a rich vertebrate fauna from several sites within Bed II, Olduvai Gorge, Tanzania. Study of these as well as recently re-organized collections from Mary Leakey's 1972 HWK EE excavations here provides a synthetic view of the faunal community of Olduvai during Middle Bed II at ∼1.7–1.4 Ma, an interval that captures the local transition from Oldowan to Acheulean technology. We expand the faunal list for this interval, name a new bovid species, clarify the evolution of several mammalian lineages, and record new local first and last appearances. Compositions of the fish and large mammal assemblages support previous indications for the dominance of open and seasonal grassland habitats at the margins of an alkaline lake. Fish diversity is low and dominated by cichlids, which indicates strongly saline conditions. The taphonomy of the fish assemblages supports reconstructions of fluctuating lake levels with mass die-offs in evaporating pools. The mammals are dominated by grazing bovids and equids. Habitats remained consistently dry and open throughout the entire Bed II sequence, with no major turnover or paleoecological changes taking place. Rather, wooded and wet habitats had already given way to drier and more open habitats by the top of Bed I, at 1.85–1.80 Ma. This ecological change is close to the age of the Oldowan-Acheulean transition in Kenya and Ethiopia, but precedes the local transition in Middle Bed II.The Middle Bed II large mammal community is much richer in species and includes a much larger number of large-bodied species (>300 kg) than the modern Serengeti. This reflects the severity of Pleistocene extinctions on African large mammals, with the loss of large species fitting a pattern typical of defaunation or ‘downsizing’ by human disturbance. However, trophic network (food web) analyses show that the Middle Bed II community was robust, and comparisons with the Serengeti community indicate that the fundamental structure of food webs remained intact despite Pleistocene extinctions. The presence of a generalized meat-eating hominin in the Middle Bed II community would have increased competition among carnivores and vulnerability among herbivores, but the high generality and interconnectedness of the Middle Bed II food web suggests this community was buffered against extinctions caused by trophic interactions.

The carnivorous feeding behavior of early Homo at HWK EE, Bed II, Olduvai Gorge, Tanzania

The regular consumption of large mammal carcasses, as evidenced by butchery marks on fossils recovered from Early Stone Age archaeological sites, roughly coincides with the appearance of Homo habilis. However, the significance of this niche expansion cannot be appreciated without an understanding of hominin feeding behavior and their ecological interactions with mammalian carnivores. The Olduvai Geochronology and Archaeology Project (OGAP) has recovered a large and well-preserved fossil assemblage from the HWK EE site, which was deposited just prior to the first appearance of Acheulean technology at Olduvai Gorge and likely represents one of the last H. habilis sites at Olduvai. This taphonomic analysis of the larger mammal fossil assemblage excavated from HWK EE shows evidence of multiple occupations over a long period of time, suggesting the site offered resources that were attractive to hominins. There was a water source indicated by the presence of fish, crocodiles, and hippos, and there was possible tree cover in an otherwise open habitat. The site preserves several stratigraphic intervals with large fossil and artifact assemblages within two of these intervals. Feeding traces on bone surfaces suggest hominins at the site obtained substantial amounts of flesh and marrow, particularly from smaller size group 1–2 carcasses, and exploited a wide range of taxa, including megafauna. A strong carnivore signal suggests hominins scavenged much of their animal foods during the two main stratigraphic intervals. In the later interval, lower carnivore tooth mark and hammerstone percussion mark frequencies, in addition to high epiphyseal to shaft fragment ratios, suggest hominins and carnivores did not fully exploit bone marrow and grease, which may have been acquired from nutritionally-stressed animals that died during a dry period at Olduvai. The diversity of fauna that preserve evidence of butchery suggests that the HWK EE hominins were opportunistic in their acquisition of carcass foods.

New Middle Pleistocene hominin cranium from Gruta da Aroeira (Portugal)

The Middle Pleistocene is a crucial time period for studying human evolution in Europe, because it marks the appearance of both fossil hominins ancestral to the later Neandertals and the Acheulean technology. Nevertheless, European sites containing well-dated human remains associated with an Acheulean toolkit remain scarce. The earliest European hominin crania associated with Acheulean handaxes are at the sites of Arago, Atapuerca Sima de los Huesos (SH), and Swanscombe, dating to 400-500 ka (Marine Isotope Stage 11-12). The Atapuerca (SH) fossils and the Swanscombe cranium belong to the Neandertal clade, whereas the Arago hominins have been attributed to an incipient stage of Neandertal evolution, to Homo heidelbergensis, or to a subspecies of Homo erectus A recently discovered cranium (Aroeira 3) from the Gruta da Aroeira (Almonda karst system, Portugal) dating to 390-436 ka provides important evidence on the earliest European Acheulean-bearing hominins. This cranium is represented by most of the right half of a calvarium (with the exception of the missing occipital bone) and a fragmentary right maxilla preserving part of the nasal floor and two fragmentary molars. The combination of traits in the Aroeira 3 cranium augments the previously documented diversity in the European Middle Pleistocene fossil record.

Lithic raw material quality of Middle Pleistocene artefacts from the Han River, Danjiangkou Reservoir Region, central China

The East Asian Acheulean is often considered distinct from African and European Acheulean technologies as large cutting tools (LCTs) are thicker and heavier on average. This distinction is generally true, but exceptions occur, particularly in thickness, as more Chinese sites are reported. It has been suggested that the raw materials available in East Asia have played a part in determining this dissimilarity. Extensive raw material studies on East Asian technologies have not yet been done to determine if this is indeed the case. It is thus important to investigate the impact of raw materials quality on the East Asian Acheulean. This paper focuses on raw material attributes for LCTs from the Danjiangkou Reservoir Region, central China (DRR), with specific focus on Middle Pleistocene artefacts from Terrace 3 of the Han River. Extensive experimental studies were done to determine raw material attributes and how those attributes affect the knapping process in the creation of LCTs. A set of variables was recorded for the experimental tools and compared with a sample of archaeological LCTs. The variables recorded included: the impurity encounter rates of various raw materials, their weathering states, grain sizes and shapes. The results indicated that hominids occupying the DRR exhibited selective behaviours for the raw materials they used to make LCTs, despite not having a wide variety of materials from which to select. It is also evident that they showed adaptability and made strategic decisions with regards to the selected raw materials for manufacture of LCTs to meet their needs.

Two Acheuleans, two humankinds: From 1.5 to 0.85 Ma at Melka Kunture (Upper Awash, Ethiopian highlands).

The Acheulean is the longest-lasting human cultural record, spanning approximately 1.5 Ma and three continents. The most comprehensive sequences are found in East Africa, where, in largescale syntheses, the Lower Pleistocene Acheulean (LPA) has often been considered a uniform cultural entity. Furthermore, the emergence and development of Acheulean technology are seen as linked to the emergence and evolution of Homo ergaster/erectus. The criterion for grouping together different lithic assemblages scattered over space and time is the presence of large cutting tools (LCTs), more than of any other component. Their degree of refinement has been used, in turn, as a parameter for evaluating Acheulean development and variability. But was the East African LPA really uniform as regards all components involved in lithic productions? The aim of this paper is to evaluate the techno-economic similarities and differences among LPA productions in a specific micro-regional and environmental context, i.e. at Melka Kunture, in the Ethiopian highlands, and in a specific period of time: between ≈1.5 Ma, when some of the earliest Acheulean complexes appeared, and 1.0-0.85 Ma, when LCTs productions became intensive and widespread. Our detailed comparative analyses investigate all aspects and phases of the chaînes opératoires. Since hominin fossil remains were discovered at some of the analyzed sites, we also discuss differences among lithic productions in relation to the changing paleoanthropological record. Our studies show that at Melka Kunture the LPA techno-complexes cannot be grouped into a single uniform entity. The assembled evidence points instead to "two Acheuleans" well-defined by a strong discontinuity in various aspects of techno-economic behaviors. This discontinuity is related to a major step in human evolution: the transition from Homo ergaster/ erectus to Homo heidelbergensis.

Venturing out safely: The biogeography of Homo erectus dispersal out of Africa

The dispersal of Homo erectus out of Africa at some 1.9 million years ago is one of the most important, crucial, and yet controversial events in human evolution. Current opinions about this episode expose the contrast between those who see H. erectus as a highly social, cooperative species seeking out new ecological opportunities to exploit, and those preferring a passive, climate driven explanation for such an event. By using geostatistics techniques and probabilistic models, we characterised the ecological context of H. erectus dispersal, from its East African origin to the colonization of Eurasia, taking into account both the presence of other large mammals and the physical characteristics of the landscape as potential factors. Our model indicated that H. erectus followed almost passively the large herbivore fauna during its dispersal. In Africa, the dispersal was statistically associated with the presence of large freshwater bodies (Rift Valley Lakes). In Eurasia, the presence of H. erectus was associated with the occurrence of geological outcrops likely yielding unconsolidated flint. During the early phase of dispersal, our model indicated that H. erectus actively avoided areas densely populated by large carnivores. This pattern weakened as H. erectus dispersed over Europe, possibly because of the decreasing presence of carnivores there plus the later acquisition of Acheulean technology. During this later phase, H. erectus was associated with limestone and shaley marl, and seems to have been selecting for high-elevation sites. While our results do not directly contradict the idea that H. erectus may have been an active hunter, they clearly point to the fact that predator avoidance may have conditioned its long-distance diffusion as it moved outside Africa. The modelled dispersal route suggests that H. erectus remained preferentially associated with low/middle latitude (i.e., comparatively warm) sites throughout its colonization history.

The Unknown Oldowan: ~1.7-Million-Year-Old Standardized Obsidian Small Tools from Garba IV, Melka Kunture, Ethiopia.

The Oldowan Industrial Complex has long been thought to have been static, with limited internal variability, embracing techno-complexes essentially focused on small-to-medium flake production. The flakes were rarely modified by retouch to produce small tools, which do not show any standardized pattern. Usually, the manufacture of small standardized tools has been interpreted as a more complex behavior emerging with the Acheulean technology. Here we report on the ~1.7 Ma Oldowan assemblages from Garba IVE-F at Melka Kunture in the Ethiopian highland. This industry is structured by technical criteria shared by the other East African Oldowan assemblages. However, there is also evidence of a specific technical process never recorded before, i.e. the systematic production of standardized small pointed tools strictly linked to the obsidian exploitation. Standardization and raw material selection in the manufacture of small tools disappear at Melka Kunture during the Lower Pleistocene Acheulean. This proves that 1) the emergence of a certain degree of standardization in tool-kits does not reflect in itself a major step in cultural evolution; and that 2) the Oldowan knappers, when driven by functional needs and supported by a highly suitable raw material, were occasionally able to develop specific technical solutions. The small tool production at ~1.7 Ma, at a time when the Acheulean was already emerging elsewhere in East Africa, adds to the growing amount of evidence of Oldowan techno-economic variability and flexibility, further challenging the view that early stone knapping was static over hundreds of thousands of years.

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.

Geochemical “fingerprints” for Olduvai Gorge Bed II tuffs and implications for the Oldowan–Acheulean transition

Bed II is a critical part of early Pleistocene Olduvai Gorge, Tanzania. Its deposits include transitions from humid to more arid conditions (with associated faunal changes), from Homo habilis to erectus, and from Oldowan to Acheulean technology. Bed II (~1.8–1.2Ma) is stratigraphically and environmentally complex, with facies changes, faulting, and unconformities, making site-to-site correlation over the ~20km of exposure difficult. Bed II tuffs are thinner, less evenly preserved, and more reworked than those of Bed I. Five marker tuffs (Tuffs IIA–IID, Bird Print Tuff (BPT)), plus local tephra, were collected from multiple sites and characterized using stratigraphic position, mineral assemblage, and electron probe microanalysis of phenocryst (feldspar, hornblende, augite, titanomagnetite) and glass (where available) composition. Lowermost Bed II tuffs are dominantly nephelinitic, Middle Bed II tuffs (BPT, Tuff IIC) have basaltic components, and upper Bed II Tuff IID is trachytic. The BPT and Tuff IID are identified widely using phenocryst compositions (high-Ca plagioclase and high-Ti hornblende, respectively), though IID was originally (Hay, 1976) misidentified as Tuff IIC at Loc 91 (SHK Annexe) in the Side Gorge. This work helps establish a high-resolution basin-wide paleolandscape context for the Oldowan–Acheulean transition and helps link hominin, faunal and archaeological records.

The East African origin of the Western European Acheulean technology: Fact or paradigm?

The East African genesis of the Western European Acheulean is an axiom for most scholars. The main component of the Acheulean, i.e. lithic assemblages, has been used to identify technical traditions, as well as to draw scenarios on the tempos, modes, causes and origin(s) of the early peopling of Europe. The presence and frequency of large shaped tools has been seen as a proxy of the emergence and development of the Acheulean technology. Despite the typological variability of these tools, which was already highlighted during the 20th century, the East African and the Western European Acheulean have been usually considered as a homogeneous entity when comparing lithic techno-complexes and creating models for the European human settlements.However, such large-scale syntheses can be flawed because the archaeological data are highly fragmented both in time and space and frequently incomparable given the different theoretical/methodological approaches adopted. The aim of this paper is to avoid such pitfalls. Accordingly, I will systematically review the Lower/early Middle Pleistocene East African assemblages and the late Lower/early Middle Pleistocene Western European assemblages which have been labeled as “Acheulean”. The contemporaneous core and flake industries will be taken into account and discussed. This will allow evaluating the theoretical/methodological implications of an East African origin for the Western European Acheulean, and understanding if it is a fact or a paradigm.

Large Cutting Tools from the Danjiangkou Reservoir Region, central China: Comparisons and contrasts with western and south Asian Acheulean

The Danjiangkou Reservoir Region (DRR) in central China has been studied since 1994 and is known for its Large Cutting Tools (LCTs), with similarities to both western and south Asian LCTs of the Acheulean industrial complex. However, the origins of LCT technology in China is a much debated topic. In this paper, we address several of the major arguments used to support an indigenous development for eastern LCTs—greater thickness, a poorer Refinement Index, greater weight, and a preference for cobbles over flakes for LCT blanks. In comparisons based on a large database of Acheulean LCTs, DRR examples are shown to compare well with Acheulean technology in terms of thickness and ‘refinement,’ traits which we here link to raw material shapes and flaking properties. A relatively more frequent use of cobbles for blanks, however, characterizes the DRR and other Chinese LCTs, but there is also regional variability in this feature. Weight, on the other hand, is consistently larger for all Chinese LCTs, including those from DRR, although these fall at the low end of the range. Nevertheless, there are important features in common between Acheulean and Chinese LCTs which indicate either a common origin or periods of admixture culturally and probably physically. These features include the use of large flake blanks, the presence of cleavers in some industries, and the shaping of handaxes by both primary and secondary flaking. The influence of regional cultural traditions on Chinese material, geographic distance and limited migration routes, cultural drift, differences in subsistence ecology, and the demographics of small population sizes seem ultimately to be responsible for the differences, and they should not be used to obscure the commonalities.

Chronology for the Cueva Victoria fossil site (SE Spain): Evidence for Early Pleistocene Afro-Iberian dispersals

Cueva Victoria has provided remains of more than 90 species of fossil vertebrates, including a hominin phalanx, and the only specimens of the African cercopithecid Theropithecus oswaldi in Europe. To constrain the age of the vertebrate remains we used paleomagnetism, vertebrate biostratigraphy and 230Th/U dating. Normal polarity was identified in the non-fossiliferous lowest and highest stratigraphic units (red clay and capping flowstones) while reverse polarity was found in the intermediate stratigraphic unit (fossiliferous breccia). A lower polarity change occurred during the deposition of the decalcification clay, when the cave was closed and karstification was active. A second polarity change occurred during the capping flowstone formation, when the upper galleries were filled with breccia. The mammal association indicates a post-Jaramillo age, which allows us to correlate this upper reversal with the Brunhes–Matuyama boundary (0.78 Ma). Consequently, the lower reversal (N-R) is interpreted as the end of the Jaramillo magnetochron (0.99 Ma). These ages bracket the age of the fossiliferous breccia between 0.99 and 0.78 Ma, suggesting that the capping flowstone was formed during the wet Marine Isotopic Stage 19, which includes the Brunhes–Matuyama boundary. Fossil remains of Theropithecus have been only found in situ ∼1 m below the B/M boundary, which allows us to place the arrival of Theropithecus to Cueva Victoria at ∼0.9–0.85 Ma. The fauna of Cueva Victoria lived during a period of important climatic change, known as the Early-Middle Pleistocene Climatic Transition. The occurrence of the oldest European Acheulean tools at the contemporaneous nearby site of Cueva Negra suggest an African dispersal into SE Iberia through the Strait of Gibraltar during MIS 22, when sea-level was ∼100 m below its present position, allowing the passage into Europe of, at least, Theropithecus and Homo bearing Acheulean technology.

The Early Acheulean technology of Barranc de la Boella (Catalonia, Spain)

Since 2007, excavations at Barranc de la Boella (Tarragona, Catalonia, Spain) have revealed three localities with rich archaeo-paleontological assemblages: La Mina, El Forn and Pit 1. Palaeontology, palaeomagnetism and cosmogenic analyses have dated these localities to close to 1 Ma. The presence of Mammuthus meridionalis, Hippopotamus antiquus, Stephanorhinus cf. hundsheimensis, Mimomys savini and Victoriamys chalinei stand out in the sample of macro and micro-mammals.The lithic assemblages from the three sites are made up of percussion cobbles, choppers, chopper-cores, cores, simple flakes, and some retouched flakes: mainly denticulates and notches. In the case of the El Forn and Pit 1 localities, two large cutting tools have been recovered: a cleaver-like tool and a pick made of hard-wearing schist. The lithic assemblage of Pit 1, which includes several refitting lithic sets, is closely associated with the remains of a young-adult Mammuthus meridionalis, in a clear butchering site context.This evidence suggests that Barranc de la Boella is the oldest European Early Acheulean site, and one of the oldest butchering site on the subcontinent during the late Early Pleistocene. The study of the variability among these three localities in similar environmental conditions, together with information from other sites, are discussed in order to gain further knowledge about the appearance of the Acheulean in Europe, and its continuity or discontinuity in relation to pre-existing technologies.

Experimental evidence for the co-evolution of hominin tool-making teaching and language.

Hominin reliance on Oldowan stone tools – which appear from 2.5mya and are believed to have been socially transmitted – has been hypothesised to have led to the evolution of teaching and language. Here we present an experiment investigating the efficacy of transmission of Oldowan tool-making skills along chains of adult human participants (N=184) using 5 different transmission mechanisms. Across six measures, transmission improves with teaching, and particularly with language, but not with imitation or emulation. Our results support the hypothesis that hominin reliance on stone tool-making generated selection for teaching and language and imply that (i) low-fidelity social transmission, such as imitation/emulation, may have contributed to the ~700,000 year stasis of the Oldowan technocomplex, and (ii) teaching or proto-language may have been pre-requisites for the appearance of Acheulean technology. This work supports a gradual evolution of language, with simple symbolic communication preceding behavioural modernity by hundreds of thousands of years.