El rol de los homininos en la formación de conjuntos arqueo-paleontológicos al aire libre: la Mina y el Forn (Barranc de la Boella, la Canonja, Tarragona) y Torralba (Torralba del Moral, Soria)

Els conjunts que integren aquesta Tesi Doctoral són la Mina i el Forn (Barranc de la Boella) i Torralba. Son dipòsits a l'aire lliure, formats en contextos fluvio-deltaics. En el registre arqueològic és freqüent trobar acumulacions formades en dipòsits sedimentaris a l'aire lliure, amb evidències de l'actuació d’hominins i carnívors. Tradicionalment, aquestes han estat utilitzades per considerar-los com els principals agents acumuladors i modificadors de la majoria d'aquests conjunts. Mitjançant estudis zooarqueològics i tafonòmics, hem pretès establir el paper d’hominins i carnívors als jaciments investigats. La mala conservació de les superfícies òssies ha limitat la preservació de modificacions tafonòmiques superficials d'origen antròpic. Davant d'aquesta mancança, hem requerit de l'ús dels perfils anatòmics per caracteritzar la naturalesa de les acumulacions òssies estudiades i identificar el paper dels grups d’hominins en la seva formació i modificació. A més, hem pretès comprendre com s'integren aquestes acumulacions en l'espai macro-regional en què aquestes poblacions desenvolupaven les seves activitats. A causa del context paleoecològic en què aquests s'emmarquen, han de ser entesos com llocs de trànsit, que no necessàriament d'activitat, que formarien part de l'espai en què aquests grups desenvoluparien les seves activitats. Les anàlisis aplicades han evidenciat contextos de diferent competència inferida al Barranc de la Boella, amb una major presència d’hominins als nivells d'elevada competència inferida, als quals l'activitat dels grups carnívors també és més gran. A Torralba s'han documentat contextos de baixa i moderada competència inferida amb escassa activitat antròpica. Les evidències de processament de les carcasses animals són poques a tots tres conjunts. Les acumulacions serien el resultat de l'acumulació d'esdeveniments independents als què el paper dels hominins es relacionaria amb les pràctiques de cerca d’aliments. El principal determinant per a la presència d'un grup d’hominins a un espai vindria donat per la presència de recursos d'interès. El risc de depredació no seria determinant. Aquestes observacions testifiquen les capacitats d'adaptació de les poblacions hominines a diferents ecosistemes.Los conjuntos incluidos en esta Tesis Doctoral son la Mina y el Forn (Barranc de la Boella) y Torralba. Se trata de depósitos al aire libre, formados en contextos fluvio-deltaicos. En el registro arqueológico es frecuente encontrar acumulaciones formadas en depósitos sedimentarios al aire libre, con evidencias de la actuación de homininos y carnívoros. Tradicionalmente, éstas han sido utilizadas para considerarlos como los principales agentes acumuladores y modificadores de la mayoría de estos conjuntos. Mediante estudios zooarqueológicos y tafonómicos, hemos pretendido establecer el papel de homininos y carnívoros en los yacimientos investigados. La mala de conservación de las superficies óseas ha limitado la preservación de modificaciones tafonómicas superficiales de origen antrópico. Ante esta carencia, hemos requerido del uso de los perfiles anatómicos para caracterizar la naturaleza de las acumulaciones óseas estudiadas e identificar el rol de los grupos de homininos en su formación y modificación. Además, hemos pretendido comprender cómo se integran estas acumulaciones en el espacio macro-regional en el que estas poblaciones desarrollaban sus actividades. Debido al contexto paleoecológico en el que estos se enmarcan, deben ser entendidos como sitios de tránsito, que no necesariamente de actividad, que formarían parte del espacio en el que estos grupos desarrollarían de sus actividades. Los análisis aplicados han evidenciado contextos de diferente competencia inferida en el Barranc de la Boella, con una mayor presencia de homininos en los niveles de elevada competencia inferida, en los que la actividad de los grupos carnívoros también es mayor. En Torralba se han documentado contextos de baja y moderada competencia inferida con escasa actividad antrópica. Las evidencias de procesado de las carcasas animales son pocas en los tres conjuntos. Las acumulaciones serían el resultado de la acumulación de eventos independientes en los que el papel de los homininos se relacionaría con las prácticas de forrajeo. El principal determinante para la presencia de un grupo de forrajeadores en un espacio vendría dado por la presencia de recursos de interés. El riesgo de depredación no sería determinante. Estas observaciones atestiguan las capacidades de adaptación de las poblaciones homininas a diferentes ecosistemas.The assemblages studied in this doctoral thesis are from la Mina and el Forn, in the Barranc de la Boella, and Torralba. These are open-air sites, formed in fluvial-deltaic contexts. In the archaeological record, it is common to find accumulations formed in open-air sedimentary deposits. These deposits may contain evidence of the presence of hominins and carnivores. Traditionally, this evidence has been used to suggest that hominins and carnivores were the main accumulating and modifying agents of these assemblages. Zooarchaeological and taphonomics methods were used in order to establish the role of hominins and carnivores in the three sites under study. The poor conservation of the bone surfaces has affected the preservation of superficial anthropogenic taphonomic modifications. We have used anatomical profiles to characterize the nature of the bone accumulations and to identify the role of hominin in its formation and modification. In addition, we have tried to understand how these accumulations are integrated into the macro-regional space in which these populations undertook their activities. These sites should be understood as transit sites, not necessarily sites of activity, which would form part of the space to which these groups belonged and in which they carried out all their activities. The applied analyses have demonstrated contexts of differing levels of competition inferred in the assemblages of the Barranc de la Boella. The observed tendency points to a greater presence of hominins in the levels of high inferred competition, in which carnivore activity is also greater. In Torralba, on the other hand, contexts of low and moderate competition with scarce anthropic activity have been documented. Evidence of animal carcass processing is scarce. No evidence has been uncovered that would attribute an anthropic origin to these accumulations, which would have resulted from independent events in which the role of the hominins was related to the practices of foraging in these territories. The main, although possibly not the only, factor determining the presence of hominins in a specific space would be the presence of resources of interest. The risk of carnivore predation does not seem to have been a deterrent. These observations attest to the capabilities of hominin to adapt to different ecosystems

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.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

Age and Date for Early Arrival of the Acheulian in Europe (Barranc de la Boella, la Canonja, Spain)

The first arrivals of hominin populations into Eurasia during the Early Pleistocene are currently considered to have occurred as short and poorly dated biological dispersions. Questions as to the tempo and mode of these early prehistoric settlements have given rise to debates concerning the taxonomic significance of the lithic assemblages, as trace fossils, and the geographical distribution of the technological traditions found in the Lower Palaeolithic record. Here, we report on the Barranc de la Boella site which has yielded a lithic assemblage dating to ,1 million years ago that includes large cutting tools (LCT). We argue that distinct technological traditions coexisted in the Iberian archaeological repertoires of the late Early Pleistocene age in a similar way to the earliest sub-Saharan African artefact assemblages. These differences between stone tool assemblages may be attributed to the different chronologies of hominin dispersal events. The archaeological record of Barranc de la Boella completes the geographical distribution of LCT assemblages across southern Eurasia during the EMPT (Early-Middle Pleistocene Transition, circa 942 to 641 kyr). Up to now, chronology of the earliest European LCT assemblages is based on the abundant Palaeolithic record found in terrace river sequences which have been dated to the end of the EMPT and later. However, the findings at Barranc de la Boella suggest that early LCT lithic assemblages appeared in the SW of Europe during earlier hominin dispersal episodes before the definitive colonization of temperate Eurasia took place

Rock magnetic experiments conducted on a representative sample (P2-9), corresponding to Zijdervelt diagrams of the Figure 3A and B.

<p>A) Progressive isothermal remanent magnetization (IRM) acquisition curve. B) Back-field curve. C) Hysteresis loop (±1 T). D) Thermomagnetic curve; arrows indicate heating and cooling cycles. E) Heating cycle of the Figure 4 D was amplified.</p

Barranc de la Boella large cutting tools (LCT).

<p>a) split cobble of schist showing trihedral pick configuration from level 2 at Pit 1 Locality (P1L) site; b) schist cleaver from level 2 at EF site.</p

Primary data from Iberian archaeological sites dating in the Early-Middle Pleistocene Transition time span (942 to 641 kyr).

a<p>MQ, Iberian biozones. ^bLCT: large cutting technology; PBC: pebble and core technology <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0103634#pone.0103634-Shea1" target="_blank">[14]</a>.</p