martes, 7 de septiembre de 2010

Renos y mamuts vivían en la Península Ibérica hace 150.000 años/The reindeer and the mammoth already lived on the Iberian Peninsula 150,000 years ago

Image: Peter NovákUn equipo integrado por miembros de la Universidad de Oviedo (UO) y la Universidad Complutense de Madrid (UCM) ha recopilado todos los hallazgos del mamut lanudo, del rinoceronte lanudo y del reno en la Península Ibérica para demostrar que, aunque de forma escasa, hace 150.000 años los grandes mamíferos, prehistóricos indicadores de clima frío, ya habitaban este territorio
La presencia del mamut lanudo (Mammuthus primigenius), del rinoceronte lanudo (Coelodonta antiquitatis), del reno (Rangifer tarandus), y en menor medida del glotón (Gulo gulo), del zorro ártico (Alopex lagopus), del buey almizclero (Ovibos moschatus) y del antílope saiga (Saiga tatarica) se ha relacionado con la escala paleoclimática elaborada a partir de la composición isotópica de oxígeno en los hielos de Groenlandia.
Los hallazgos de faunas de clima frío en la Península Ibérica coinciden con los momentos de mayor enfriamiento global registrados en los hielos de Groenlandia”, según Diego Álvarez-Lao, autor principal del trabajo e investigador en el Área de Paleontología de la Universidad de Oviedo.
Las “faunas glaciares” entran en la Península en ese momento porque las condiciones ambientales en el centro y norte de Europa son tan extremas que los animales se vieron obligados a emigrar al sur, donde el clima era menos extremo. Hace 44.000 años estos animales se hicieron más comunes en la Península Ibérica pero de forma episódica.
El aumento de temperaturas causó una crisis biológica
. Según el equipo, los últimos hallazgos de estas especies frías datan de hace unos 10.000 años, y coinciden con el final de las glaciaciones. En ese momento, el clima se calentó en todo el hemisferio norte y el hábitat propicio para estas faunas se fue reduciendo a latitudes cada vez más nórdicas y a espacios más pequeños.
“El aumento de las temperaturas causó una auténtica crisis biológica para estos animales especializados en climas de extremo frío. Algunas especies como el reno o el zorro ártico encontraron su nuevo hábitat en las regiones árticas del planeta, donde aún hoy sobreviven. Otras como el mamut y el rinoceronte lanudo tuvieron menos suerte”
Estas especies convivieron con las distintas culturas humanas. Hay evidencias en algunos yacimientos del País Vasco, Navarra y Cataluña de que los neandertales coexistieron con los mamuts y los renos en determinados momentos. No obstante, la mayor parte de evidencias de estas faunas coinciden con las épocas de las culturas Ggravetiense, Ssolutrense y Mmagdaleniense (durante el Paleolítico Superior, en la Europa Occidental).

A team made up of members of the University of Oviedo (UO) and the Complutense University of Madrid (UCM) have gathered together all findings of the woolly mammoth, the woolly rhinoceros and the reindeer in the Iberian Peninsula to show that, although in small numbers, these big mammals, prehistoric indicators of cold climates, already lived in this territory some 150,000 years ago.
The presence of the woolly mammoth (Mammuthus primigenius), the woolly rhinoceros (Coelodonta antiquitatis), the reindeer (Rangifer tarandus), and to a lesser extent the wolverine (Gulo gulo), the arctic fox (Alopex lagopus), the musk-ox (Ovibos moschatus) and the Saiga antelope (Saiga tatarica), has been linked to the paleoclimatic scale created on the basis of the isotopic composition of oxygen in the ice of Greenland.
"The findings of cold climate fauna in the Iberian Peninsula coincide with the periods of greatest global cooling recorded in the ice of Greenland", according to Diego Álvarez-Lao, main author of the work and researcher in the Palaeontology Department of the UO
The "glacial fauna" entered the Peninsula at that time because the environmental conditions in central and northern Europe were so extreme that the animals were obliged to migrate to the south, where the climate was less severe. 44,000 years ago these animals became more common in the Iberian Peninsula but only for periods.
The increase in temperatures caused a biological crisis.
According to the team, the last findings of these cold species date back some 10,000 years, and coincide with the end of the glaciations. At that time, the climate became warmer in the whole northern hemisphere and the favourable habitat for these faunae was reduced to increasingly more northern latitudes and to smaller spaces.
"The increase in temperatures caused a genuine biological crisis for these animals from extremely cold climates. Some species such as the reindeer and the arctic fox found their new habitat in the arctic regions of the planet, where they still survive today. Others, such as the woolly mammoth and the woolly rhinoceros weren't so lucky".
These species lived alongside different human cultures
. There is evidence in some sites of the Basque country, Navarra and Catalonia that the Neanderthals coexisted with the mammoths and the reindeer at specific times. However, the majority of evidence of these faunae coincides with the periods of the Gravettian, Solutrean and Magdalenian cultures (during the Upper Paleolithic era in West Europe)

Tomado de/Taken from Plataforma SINC (Español)/AlphaGalileo (English)

Abstract of the paper
Chronological distribution of Pleistocene cold-adapted large mammal faunas in the Iberian Peninsula
Diego J. Álvarez-Lao and Nuria García
Quaternary International, Volume 212, Issue 2, 1 February 2010, Pages 120-128

Abstract
During the coldest episodes of the Late Pleistocene, the cold-adapted large mammal faunas moved southward, reaching southern regions such as the Iberian Peninsula. Thus, during the Late Pleistocene, remains of Mammuthus primigenius, Coelodonta antiquitatis and Rangifer tarandus were found in Iberia. In addition, four other cold-adapted species (Gulo gulo, Alopex lagopus, Ovibos moschatus and Saiga tatarica) were present, although in very low proportions. All published chronologies from these Iberian findings, as well as new radiocarbon dates, were compiled and subsequently correlated with the published paleoclimatic information for the Iberian Late Pleistocene.
These cold-adapted faunas were present in the Iberian Peninsula from at least the late Middle Pleistocene (MIS 6), and several findings, although chronologically imprecise, were dated to the first half of the Late Pleistocene. After about 44 ka BP, these faunas became relatively abundant on the Iberian Peninsula. However, there is a chronological gap between 31 and 26 ka, in which these faunas were practically absent in Iberia. Subsequently, during MIS 2, the presence of these species was again well documented. The last Iberian occurrences of most of these species have been registered during the LGM, except the reindeer, that survived until the end of the Younger Dryas. The chronology of the Iberian findings of cold-adapted large mammal faunas is consistent with the paleoclimatical evidence provided by other sources.