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In the last decade, the identification of bone fragments by peptide mass fingerprinting or zooarchaeology by mass spectrometry is developing as a powerful tool in Quaternary palaeontology. The sequence of amino acids that make up the bone collagen molecule shows slight variations between taxa, which can be studied by mass spectrometry for taxonomic purposes. This requires reference databases that allow peptide identification. Although the cave bear (Ursus spelaeus Rosenmüller, 1794) is a common component in many European Pleistocene cave sites, no peptide fingerprint taxonomic study has paid special attention to this species up to now. For peptide markers in Ursidae, the most recent proposal is based on collagen obtained from a modern brown bear sample. In this work we attempt to cover this gap by studying bone collagen of cave and brown bear samples from different origins and different chronology, applying matrix-assisted laser desorption/ionisation time-of-flight mass spectrometry (MALDI TOF). We also performed an in-silico study of ursid bone collagen sequences published in databases. In our results we detected some discrepancies between the peptides obtained from both in silico and MALDI TOF analysis of fossil collagen and those published in the literature, in which we conclude that there are some misidentified peptides. The identification of skeletal remains by means of their peptide fingerprint is proving to be a powerful tool in palaeontology, which will bear greater fruit once the limitations of a technique that is in its initial stages have been overcome.

Financiado para publicación en acceso aberto: Universidade da Coruña/CISUG [Abstract] Sopeña is a limestone shelter in the northern slopes of the Cantabrian range of mountains of northern Spain. A long sequence of in situ nearly undisturbed archaeological strata has been documented there, including seven Gravettian, four Early Upper Palaeolithic and a minimum of four Mousterian levels, and bedrock has not been reached. Dating the last occupations by Neanderthals and their substitution by modern humans in northern Spain is a currently debated issue, made difficult by the scarcity of sites bearing those levels and able to produce reliable dates. Earlier work in Sopeña pointed to a disappearance of the Mousterian that was later than proposed by other authors on other sites of what is known as Cantabrian Spain, a mountainous fringe facing the Bay of Biscay. Here we present 11 new dates, corresponding to Gravettian, Early Upper Palaeolithic and Mousterian levels, and some of these new dates are ultrafiltered. It is concluded that although the earliest Sopeña Gravettian dates are older than those proposed elsewhere in the region, we do not have still enough information to produce a definite model for the Gravettian of this site. Furthermore, a Bayesian model is produced for the interpretation of the dates obtained for the earliest Upper and the latest Middle Palaeolithic, and it is concluded that the disappearance of the Mousterian in Sopeña is indeed a few millennia later than currently proposed by others in the region, while that available dates cannot shed unquestionable light on the existence or not of a hiatus between the dismissal of Neanderthals and the earliest arrival othe Upper Palaeolithic technocultures at the site. The dating of the new bone samples from Sopeña was made possible thanks to the financial support of the PalArq Foundation (https://fundacionpalarq.com/). Funding for open access: Universidade da Coruña/CISUG

[Resumen] Se realiza un análisis por prospección geofísica mediante tomografía eléctrica (ERT, electrical resistivity tomography) en el abrigo de Sopeña (Asturias) y su zona inmediata. El abrigo contiene un interesante yacimiento del Paleolítico Medio superior y Paleolítico Superior inicial, desvelado en un sondeo arqueológico de hasta 3 metros de profundidad sin haber alcanzado la base rocosa. Su entrada actual está protegida por grandes bloques caídos de la cornisa, recubiertos por gruesas coladas estalagmíticas. Esta disposición posiblemente atestigua una posición original de la zona de ocupación humana más interna, dentro de una cueva de mayores dimensiones. Mediante este análisis hemos localizado varios posibles rellenos sedimentarios a cierta profundidad en el exterior del abrigo. Se abre así la posibilidad de muestrear en un futuro esos rellenos, en busca de posibles niveles de ocupación más antiguos. [Abstract] A geophysical survey analysis is carried out using electrical resistivity tomography (ERT) in the Sopeña shelter (Asturias) and its immediate area. The shelter contains an interesting Upper Middle Palaeolithic and Early Upper Palaeolithic site, revealed in an archaeological test pit up to 3 metres deep without having reached the bedrock. Its current entrance is protected by large blocks fallen from the ledge, covered by thick stalagmitic flows. This arrangement possibly testifies to an original position of the innermost human occupation zone, inside a larger cave. Through this analysis we have located several possible sedimentary fills at a certain depth on the outside of the shelter. This opens up the possibility of sampling these fills in the future, in search of possible older occupation levels.

Con autorización de la revista para autores CSIC, [EN] In this paper we present 13 new radiocarbon datings of brown bear (Ursus arctos L.) remains from caves of the western half of the Cantabrian Mountains (Galicia, Asturias, Cantabria). This dates, as well as other previously reported, range from more than 40,000 years BP to 2,442 ± 61 years cal BP, belonging mostly to the early Holocene. From a whole of 26 datings, only 3 are of Pleistocene age. In order to complete the distribution in space and time in the Iberian peninsula, we review the literature on this species presence and its chronology by radiocarbon dating or archaeological culture when it exists. The presence of the brown bear has been observed in at least 143 sites. Oldest mentions are from Middle Pleistocene from the south of the Iberian peninsula. In Upper Pleistocene, sites cover the whole peninsula, with only 5 radiocarbon dates. Sites with Pleistocene fossils are a few more than the Holocene ones. There are several problems with the observed distribution. Firstly, as for the vast majority of terrestrial biocenosis, even if the species was present there are not preserved remains. An example of this is the lack of Holocene remains in places we know it was present according to the historical literature. In general, there are gaps in the distribution that coincide with no limestone lithology. Furthermore, there is a bias related to the intensity of research in certain areas. It was suggested that brown bear population increased when cave bear (Ursus spelaeus ROSENMÜLLER) wiped out, but only in 12.5 % of the places in which both species are present is possible to see a substitution. The number of brown bears in every site is low before and after the extinction of its alleged competitor. Our results suggest that the denning ecology was different from the cave bear and, like nowadays, brown bears used different types of dens, like holes in the ground, inside trees or smaller natural caves. In the XVI century the population begins to decrease, till reaching its minimum in the XX century, with two surviving populations in Cantabrian Mountains and Pyrenees, but population began to drop since the Neolithic, probably due to the pressure caused by the expansion of human activities., [ES] Se presentan los resultados de 12 nuevas dataciones radiométricas 14C de restos de oso pardo (Ursus arctos L.) procedentes de cuevas de la mitad occidental de la Cordillera Cantábrica (Galicia-Asturias-Cantabria). Estas dataciones, además de otras previamente publicadas, datan la presencia de la especie en cuevas de esta zona desde hace más de 40.000 años BP a 2.442 ± 61 años cal BP, correspondiendo la mayor parte a los inicios del Holoceno. La revisión bibliográfica, realizada sobre la presencia de esta especie en otros yacimientos de la Península, muestra la existencia de estos en al menos 143 sitios. En el Pleistoceno Superior los yacimientos se distribuyen por toda la Península y superan en número a aquellos con restos holocenos. En general se producen vacíos en la distribución coincidentes con las zonas de litología no caliza. También, existe un sesgo relacionado con la intensidad de la investigación en ciertas áreas. Otro factor puede ser la competencia con el oso cavernario (Ursus spelaeus ROSENMÜLLER) por recursos o hábitat, aunque sólo el 12,5% de los yacimientos en donde aparecen las dos especies muestran la sustitución de una especie por la otra tras la extinción del oso cavernario. El descenso de población en oso pardo se refleja en la escasez de yacimientos a partir del Neolítico, probablemente debido a la presión ejercida por la expansión de las actividades humanas, hasta llegar a las dos poblaciones actuales relictas en la Península Ibérica (Cordillera Cantábrica y Pirineos)., Este trabajo es parte de la Tesis Doctoral de AGV, y una contribución al Proycto de Investigación PROXIES II ( CGL2011-30141), del Ministerio de Economía y Competitividad, y no sería posible sin el apoyo del Instituto de Xeoloxía Isidro Parga Pondal

The European brown bear (Ursus arctos) shows a particular phylogeography that has been used to illustrate the model for contraction-expansion dynamics related to glacial refugia in Southern European peninsulas. Recent studies, however, have nuanced the once generally accepted paradigm, indicating the existence of cryptic refugia for some species further north. In this paper we collected available data on chronology and mitochondrial haplotypes from Western European brown bears, adding new sequences from present day individuals from the Cantabrian (North Iberia) area, in order to reconstruct the dynamics of the species in the region. Both genetics and chronology show that the Iberian Pleistocene lineages were not the direct ancestors of the Holocene ones, the latter entering the Peninsula belatedly (around 10,000 years BP) with respect to other areas such as the British Isles. We therefore propose the existence of a cryptic refugium in continental Atlantic Europe, from where the bears would expand as the ice receded. The delay in the recolonization of the Iberian Peninsula could be due to the orographic characteristics of the Pyrenean-Cantabrian region and to the abundant presence of humans in the natural entrance to the Peninsula.