Arnold L.J.,University of Adelaide |
Demuro M.,University of Adelaide |
Pares J.M.,National Research Center sobre la Evolucion Humana |
Perez-Gonzalez A.,National Research Center sobre la Evolucion Humana |
And 3 more authors.
Quaternary International | Year: 2015
The emergence of alternative luminescence dating techniques, such as thermally transferred optically stimulated luminescence (TT-OSL), post-infrared infrared stimulated luminescence (pIR-IRSL) and OSL dating of individual quartz 'supergrains', has opened up new possibilities for establishing numerical age control on sedimentary deposits that exceed the traditional upper age limits of quartz OSL dating. In this study, we evaluate the reliability of these 'extended-range' luminescence dating techniques over Middle and Early Pleistocene timescales using two approaches: (i) a broad-scale synthesis of extended-range luminescence chronologies published so far as part of known-age comparison studies; (ii) a series of new TT-OSL and pIR-IRSL case studies at the palaeoanthropological sites of Galería, Sima del Elefante and Gran Dolina (Atapuerca, Spain). The published known-age TT-OSL datasets (n=82) and supergrain OSL datasets (n=3) display good correspondence (i.e., suitably linear and proportion relationships) with associated age control. The known-age pIR-IRSL datasets (n=228) display more inter-sample scatter, though there is general support for the reliability of more stringent pIR-IRSL protocols and multiple-elevated temperature pIR-IRSL approaches over Late and Middle Pleistocene timescales. While these reliability assessments are encouraging, there remains a clear need for more widespread, known-age empirical assessments of extended-range luminescence techniques beyond ~300-400ka. The ages obtained at Atapuerca using single-grain TT-OSL and pIR-IRSL measurement temperatures of 225°C (pIR-IR225) are in agreement with independent age control over an age range spanning ~240-930ka. In contrast, the pIR-IRSL chronologies obtained using a more stringent measurement temperature of 290°C (pIR-IR290) consistently overestimate the expected ages of the Atapuerca sequences. The single-grain TT-OSL ages obtained at Gran Dolina permit calculation of a new weighted mean age of 846±57ka for the Homo antecessor palaeoanthropological horizon (unit TD6). The known-age Atapuerca case studies highlight the feasibility, and advantages, of applying TT-OSL dating at the single-grain scale of analysis and demonstrate that the suitability of pIR-IRSL dating protocols can vary significantly at a site or regional scale. Together, our analyses show that no single extended-range luminescence dating technique is likely to be universally applicable to all samples. Collectively, however, these approaches offer good potential for obtaining reliable chronologies, and they are likely to offer the greatest benefits when applied in tandem to individual samples. © 2014 Elsevier Ltd and INQUA.
Martinez I.,University of Alcalá |
Martinez I.,Complutense University of Madrid |
Rosa M.,University of Alcalá |
Quam R.,Complutense University of Madrid |
And 12 more authors.
Quaternary International | Year: 2013
The present study presents new data on the abilities of Homo heidelbergensis to produce and perceive the sounds emitted during modern human spoken language. The pattern of sound power transmission was studied through the outer and middle ears in five individuals from the Sima de los Huesos, four chimpanzees and four modern humans. The results were then used to calculate the occupied bandwidth of the outer and middle ears, an important variable related with communicative capacities. The results demonstrate that the Atapuerca SH hominins were similar to modern humans in this aspect, falling within the lower half of the range of variation, and clearly distinct from chimpanzees. Specifically, the Atapuerca SH hominins show a bandwidth that is slightly displaced and considerably extended to encompass the frequencies that contain relevant acoustic information in human speech, permitting the transmission of a larger amount of information with fewer errors. At the same time, the presence of a complete cervical segment of the spinal column associated with Cranium 5 from the Sima de los Huesos Middle Pleistocene site (Sierra de Atapuerca, Spain) makes it possible to estimate the vocal tract proportions in H. heidelbergensis for the first time. The results demonstrate that it is similar to the reconstructed vocal tract in the La Ferrassie 1 Neandertal individual, which has been suggested to have been capable of producing the full range of sounds emitted during modern human spoken language. These results in the Atapuerca (SH) hominins are consistent with other recent suggestions for an ancient origin for human speech capacity. © 2012 Elsevier Ltd and INQUA.
Arnold L.J.,National Research Center sobre la Evolucion Humana |
Demuro M.,National Research Center sobre la Evolucion Humana |
Pares J.M.,National Research Center sobre la Evolucion Humana |
Arsuaga J.L.,Complutense University of Madrid |
And 3 more authors.
Journal of Human Evolution | Year: 2014
Establishing a reliable chronology on the extensive hominin remains at Sima de los Huesos is critical for an improved understanding of the complex evolutionary histories and phylogenetic relationships of the European Middle Pleistocene hominin record. In this study, we use a combination of 'extended-range' luminescence dating techniques and palaeomagnetism to provide new age constraint on sedimentary infills that are unambiguously associated with the Sima fossil assemblage. Post-infrared-infrared stimulated luminescence (pIR-IR) dating of K-feldspars and thermally transferred optically stimulated luminescence (TT-OSL) dating of individual quartz grains provide weighted mean ages of 433 ± 15 ka (thousands of years) and 416 ± 19 ka, respectively, for allochthonous sedimentary horizons overlying the hominin-bearing clay breccia. The six replicate luminescence ages obtained for this deposit are reproducible and provide a combined minimum age estimate of 427 ± 12 ka for the underlying hominin fossils. Palaeomagnetic directions for the luminescence dated sediment horizon and underlying fossiliferous clays display exclusively normal polarities. These findings are consistent with the luminescence dating results and confirm that the hominin fossil horizon accumulated during the Brunhes Chron, i.e., within the last 780 ka. The new bracketing age constraint for the Sima hominins is in broad agreement with radiometrically dated Homo heidelbergensis fossil sites, such as Mauer and Arago, and suggests that the split of the H. neanderthalensis and H. sapiens lineages took place during the early Middle Pleistocene. More widespread numerical dating of key Early and Middle Pleistocene fossil sites across Europe is needed to test and refine competing models of hominin evolution. The new luminescence chronologies presented in this study demonstrate the versatility of TT-OSL and pIR-IR techniques and the potential role they could play in helping to refine evolutionary histories over Middle Pleistocene timescales. © 2013 Elsevier Ltd.
Cuenca-Bescos G.,University of Zaragoza |
Melero-Rubio M.,University of Zaragoza |
Rofes J.,University of Zaragoza |
Martinez I.,University of Alcalá |
And 5 more authors.
Journal of Human Evolution | Year: 2011
The dispersal of hominins may have been favored by the opening of the landscape during the Early-Middle Pleistocene transition (EMP) in Western Europe. The structure of the small-vertebrate assemblages of the archaeo-paleontological karstic site of Gran Dolina in Atapuerca (Burgos, Spain) shows important environmental and climatic changes in the faunal succession, across the Matuyama-Brunhes boundary at 780 ka. These changes are interpreted to indicate impoverishment of the forests, along with an increase in dry meadows, and open lands in general that entailed a tendency towards the loss of diversity in small-vertebrate communities above the EMP. We evaluate variation in diversity of the faunal succession of Gran Dolina using Shannon's Second Theorem as an index of ecosystem structure. The long cultural-stratigraphic sequence of Gran Dolina during the EMP is somewhat similar in its completeness and continuity to that in the locality of Gesher Benot Ya'aqov in the Upper Jordan Valley. We also evaluate related data including faunal and floral (pollen) succession. Both localities present cold, dry and humid, warm fluctuations at the transition between the Early and the Middle Pleistocene. Comparisons between these sites present opportunities to understand large-scale climatic changes. © 2010 Elsevier Ltd.
Olle A.,Institute Of Paleoecologia Humana I Evolucio Social |
Olle A.,Rovira i Virgili University |
Pedergnana A.,Institute Of Paleoecologia Humana I Evolucio Social |
Pedergnana A.,Rovira i Virgili University |
And 6 more authors.
Quaternary International | Year: 2016
In general, quartz and most of non-flint rocks have not been extensively studied from a functional point of view. Very frequently the definitions of micro-features connected with flint surfaces have been used to describe those encountered on non-flint tools. This circumstance has repeatedly posed serious methodological problems for evaluating the accuracy of functional results when analysing use-wear on quartz and quartzite implements. This is due to the intrinsic divergences in morphology and distribution of use-wear with regard to the different lithic raw materials.Even though important efforts to systematise use-wear features on quartz have been done almost since the beginning of the discipline, there continues to be confusion and lack of standardisation regarding terminology in this aspect.In this paper, we try to contribute to new insights in this research by means of selecting examples from an extensive experimental programme involving different raw materials: from rock crystal (the purest form of quartz found in nature) to vein quartz and quartzite, with the latter two materials extensively used for knapping throughout Prehistory and still poorly understood in terms of microwear. For data recording, we preferentially used sequential experiments and resorted to both Optical Light and Scanning Electron Microscopy.We focused our interest on describing the main groups of wear features. The results obtained allowed us to assess the different mechanical behaviours under the stressors induced by tool-use from a group of raw materials with the same chemical composition but very different in structure. Furthermore, we propose the revision of some terms commonly employed when documenting micro-wear on quartz and similar rocks, as well as recurring concepts coming from materials and geological sciences (e.g. tribology, quartz exoscopy...). © 2016 Elsevier Ltd and INQUA.
PubMed | Institute Of Paleoecologia Humana I Evolucio Social
Type: Historical Article | Journal: Proceedings of the National Academy of Sciences of the United States of America | Year: 2010
Here we report the discovery of a new late Lower Pleistocene site named Vallparads (Barcelona, Spain) that produced a rich archeological and paleontological sequence dated from the upper boundary of the Jaramillo subchron to the early Middle Pleistocene. This deposit contained a main archeological layer with numerous artifacts and a rich macromammalian assemblage, some of which bore cut marks, that could indicate that hominins had access to carcasses. Paleomagnetic analysis, electron spin resonance-uranium series (ESR-US), and the biostratigraphic chronological position of the macro- and micromammal and lithic assemblages of this layer reinforce the proposal that hominins inhabited Europe during the Lower Pleistocene. The archeological sequence provides key information on the successful adaptation of European hominins that preceded the well-known fossil population from Atapuerca and succeeded the finds from Orce basin. Hence, this discovery enables us to close a major chronological gap in the early prehistory of Iberia. According to the information in this paper and the available data from these other sites, we propose that Mediterranean Western Europe was repeatedly and perhaps continuously occupied during the late Matuyama chron.