Institute Evolucion en Africa IDEA

San Andrés del Rabanedo, Spain

Institute Evolucion en Africa IDEA

San Andrés del Rabanedo, Spain
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Sevilla P.,Complutense University of Madrid | Arsuaga J.L.,Complutense University of Madrid | Arriaza M.C.,University of Alcalá | Arriaza M.C.,Institute Evolucion en Africa IDEA | And 3 more authors.
PLoS ONE | Year: 2015

This paper reports the first find of pika remains in the Iberian Peninsula, at a site in central Spain. A fragmented mandible of Ochotona cf. pusilla was unearthed from Layer 3 (deposited some 63.4±5.5 ka ago as determined by thermoluminescence) of the Buena Pinta Cave. This record establishes new limits for the genus geographic distribution during the Pleistocene, shifting the previous edge of its known range southwest by some 500 km. It also supports the idea that, even though Europe's alpine mountain ranges represented a barrier that prevented the dispersal into the south to this and other taxa of small mammals from central and eastern Europe, they were crossed or circumvented at the coldest time intervals of the end of the Middle Pleistocene and of the Late Pleistocene. During those periods both the reduction of the forest cover and the emersion of large areas of the continental shelf due to the drop of the sea level probably provided these species a way to surpass this barrier. The pika mandible was found accompanying the remains of other small mammals adapted to cold climates, indicating the presence of steppe environments in central Iberia during the Late Pleistocene. Copyright © 2015 Laplana et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

Arriaza M.C.,University of Alcalá | Arriaza M.C.,Institute Evolucion en Africa IDEA | Dominguez-Rodrigo M.,Institute Evolucion en Africa IDEA | Dominguez-Rodrigo M.,Complutense University of Madrid
Quaternary Science Reviews | Year: 2016

In the past twenty years, skeletal part profiles, which are prone to equifinality, have not occupied a prominent role in the interpretation of early Pleistocene sites on Africa. Alternatively, taphonomic studies on bone surface modifications and bone breakage patterns, have provided heuristic interpretations of some of the best preserved archaeological record of this period; namely, the Olduvai Bed I sites. The most recent and comprehensive taphonomic study of these sites (Domínguez-Rodrigo et al., 2007a) showed that FLK Zinj was an anthropogenic assemblage in which hominins acquired carcasses via primary access. That study also showed that the other sites were palimpsests with minimal or no intervention by hominins. The FLK N, FLK NN and DK sequence seemed to be dominated by single-agent (mostly, felid) or multiple-agent (mostly, felid-hyenid) processes. The present study re-analyzes the Bed I sites focusing on skeletal part profiles. Machine learning methods, which incorporate complex algorithms, are powerful predictive and classification methods and have the potential to better extract information from skeletal part representation than past approaches. Here, multiple algorithms (via decision trees, neural networks, random forests and support vector machines) are combined to produce a solid interpretation of bone accumulation agency at the Olduvai Bed I sites. This new approach virtually coincides with previous taphonomic interpretations on a site by site basis and shows that felids were dominant accumulating agents over hyenas during Bed I times. The recent discovery of possibly a modern lion-accumulated assemblage at Olduvai Gorge (Arriaza et al., submitted) provides a very timely analog for this interpretation. © 2016 Elsevier Ltd.

Dominguez-Rodrigo M.,Institute Evolucion en Africa IDEA | Dominguez-Rodrigo M.,Complutense University of Madrid | Garcia-Perez A.,Spanish University for Distance Education (UNED)
PLoS ONE | Year: 2013

Orientation of archaeological and paleontological materials plays a prominent role in the interpretation of site formation processes. Allochthony and authochthony are frequently assumed from orientation patterns or lack thereof. Although it is still debated to what extent orientation of items can be produced in original depositional contexts, the recent use of GIS tools to measure orientations has highlighted several ways of reproducing A-axes with which to address these taphonomic issues. In the present study, the three most relevant A-axis types are compared to test their accuracy in reproducing water current direction. Although results may be similar in specific bone shapes, differences are important in other shapes. As known in engineering working with wind and fluid mechanics (developing shape optimization), longitudinal symmetrical axes (LSA) are the one that best orient structures against or in the same direction of wind and water. The present work shows that this is also the case for bones (regardless of shape), since LSA produce the most accurate estimates of flow direction. This has important consequences for the interpretation of orientation patterns at sites, since this type of axis is still not properly reproduced by GIS available tools. © 2013 Domínguez-Rodrigo, García-Pérez.

Arriaza M.C.,University of Alcalá | Arriaza M.C.,Institute Evolucion en Africa IDEA | Huguet R.,Institute Catala Of Paleoecologia Humana I Evolucio Social | Huguet R.,Rovira i Virgili University | And 6 more authors.
Quaternary International | Year: 2015

Lagomorph remains at Pleistocene sites may accumulate through the action of hominins, raptors or carnivores. Actualistic studies have described reliable taphonomic indicators that allow human and non-human involvement in such accumulations to be distinguished. However, discriminating between possible animal predators is not easy, because the prey remnants they leave may undergo the same kinds of taphonomic transformation. The main aim of the present work was to identify the agent, human or non-human, that accumulated the lagomorph remains at the Navalmaíllo Rock Shelter site (Pinilla del Valle, Madrid). For this, 1) established taphonomic criteria, such as anatomical representation, were taken into account, 2) the presence of infant lagomorphs was examined by determining the age of the individual animals, 3) and coprolite remains adhered to fossils were identified. This new use of the latter two criteria aided in the identification of the predator responsible for the accumulation of remains. The results suggest that this was a small carnivore, probably an Iberian lynx. © 2015 Elsevier Ltd and INQUA.

Panera J.,Institute Evolucion En Africa Idea | Rubio-Jara S.,Institute Evolucion En Africa Idea | Yravedra J.,Complutense University of Madrid | Blain H.-A.,Institute Catala Of Paleoecologia Humana I Evolucio Social Iphes | And 3 more authors.
Quaternary International | Year: 2014

This paper presents the findings from four sites with proboscidean remains associated with Middle Palaeolithic stone tools from the Manzanares Valley Complex Terrace of Butarque (CTB), which has been dated to between the final Middle Pleistocene (MIS 6, 190-130ka) and the early Late Pleistocene (MIS 5, 130-74-71ka). We review the direct and indirect evidence of proboscidean exploitation in the Middle Paleolithic sites of Europe, and provide information on Lower Paleolithic European sites with proboscidean remains and stone tools. Geological, chronological, bio-stratigraphic and climatic data of the CTB are provided, and the sites with proboscidean remains and Middle Palaeolithic stone tools are described in detail.Systematic exploitation of large mammals during the Middle Palaeolithic, and even their regular hunting, is widely accepted. However, the exploitation of proboscideans is not as evident in the archaeological record of this period. The exploitation of proboscideans cannot be considered as merely occasional before the Upper Palaeolithic, and although there is more evidence of the exploitation of these mega-herbivores during the Lower than during the Middle Palaeolithic, the discoveries from the Manzanares Valley state that, at least in this area, proboscideans continued to play an important role with regards to the exploitation of the environmental resources. © 2013 Elsevier Ltd and INQUA.

PubMed | Institute Evolucion en Africa IDEA, Complutense University of Madrid, University of Dar es Salaam, CSIC - National Museum of Natural Sciences and University of Alcalá
Type: Journal Article | Journal: PloS one | Year: 2015

Age and sex selection of prey is an aspect of predator ecology which has been extensively studied in both temperate and African ecosystems. This dimension, along with fecundity, survival rates of prey and mortality factors other than predation are important in laying down the population dynamics of prey and have important implications in the management of species. A carnivore den located in the short-grassland ecological unit of the Serengeti was studied. Sex- and age- class (using five age categories) of the wildebeest remains recovered were analyzed through horn morphology, biometrics of the bones and tooth wear patterns. We compared our results with previous studies from lion and hyaena kills through multivariate analyses. Seasonality of the accumulation was analyzed through tooth histology. PCA and CVA results show that age class selection by predators depends on season, habitat-type, and growth rate of the wildebeest population. Female-biased predation was found to contradict classical hypotheses based on territorial male behaviour. The lion and spotted hyaena showed strong selection on age classes, contrary to previous studies. Migratory wildebeest sex ratio is regulated through differential predation by seasons and female deaths in the wet season are a trade-off for population stability. These data are crucial for an effective management of the species and the new method created may be useful for different carnivore species and their prey.

PubMed | Institute Evolucion en Africa IDEA and University of Alcalá
Type: Journal Article | Journal: PloS one | Year: 2016

Analytic models have been developed to reconstruct early hominin behaviour, especially their subsistence patterns, revealed mainly through taphonomic analyses of archaeofaunal assemblages. Taphonomic research is used to discern which agents (carnivores, humans or both) generate the bone assemblages recovered at archaeological sites. Taphonomic frameworks developed during the last decades show that the only large-sized carnivores in African biomes able to create bone assemblages are leopards and hyenas. A carnivore-made bone assemblage located in the short-grassland ecological unit of the Serengeti (within Olduvai Gorge) was studied. Taphonomic analyses of this assemblage including skeletal part representation, bone density, breakage patterns and anatomical distribution of tooth marks, along with an ecological approach to the prey selection made by large carnivores of the Serengeti, were carried out. The results show that this bone assemblage may be the first lion-accumulated assemblage documented, although other carnivores (namely spotted hyenas) may have also intervened through postdepositional ravaging. This first faunal assemblage potentially created by lions constitutes a new framework for neotaphonomic studies. Since lions may accumulate carcasses under exceptional circumstances, such as those documented at the site reported here, this finding may have important consequences for interpretations of early archaeological and paleontological sites, which provide key information about human evolution.

Rubio-Jara S.,Institute Evolucion En Africa Idea | Panera J.,National Research Center Sobre La Evolucion Humana Cenieh | Rodriguez-de-Tembleque J.,Asociacion Nacional el Hombre y el Medio | Santonja M.,National Research Center Sobre La Evolucion Humana Cenieh | Perez-Gonzalez A.,National Research Center Sobre La Evolucion Humana Cenieh
Quaternary International | Year: 2015

The highest concentration of Palaeolithic sites known in the Iberian Peninsula is located in the lower stretches of the Manzanares and Jarama rivers. This area, together with a number of zones in the Tagus valley, constitutes one of the most important archives for the knowledge of the European Pleistocene. The purpose of this paper is to establish the chronological frame and the technological strategies implemented in manufacturing lithic tools during the Acheulean techno-complex in the middle stretch of the Tagus basin. Use of large flakes for making bifaces is common in the Acheulean assemblages from this area, as well as in the rest of the Iberian Peninsula and the south of France.The earliest Acheulean evidence has been dated to between MIS 15 and MIS 13. From MIS 11/MIS 9 on, this techno-complex is widespread in the region, until MIS 6, when the last evidence has been recorded. Handaxes, cleavers on flake and trihedral picks dominate in the châines opératoires of façonnage, which are present in significant percentages. Short châines opératoires of débitage prevail in quartzite, and discoid and polyhedric in flint. Most retouched tools are seldom elaborate. Lithic assemblages with châines opératoires of façonnage exclusively represented by handaxes start to be recorded towards the end of the Middle Pleistocene. These handaxes are more elaborate than previous and the retouched tools are more complex.Among the activities identified in the sites excavated in overbank facies, exploitation of large mammals, particularly proboscideans, is outstanding, as well as the manufacture of lithic tools and the exploitation of primary flint outcrops. The recording of long recurrent settlements on the same location is remarkable. © 2015 Elsevier Ltd and INQUA.

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