The Experts below are selected from a list of 240 Experts worldwide ranked by ideXlab platform
Margarita A. Erbajeva - One of the best experts on this subject based on the ideXlab platform.
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Changes in the fossil mammal faunas of Western Transbaikalia during the Pliocene–Pleistocene boundary and the Early–Middle Pleistocene transition
Quaternary International, 2005Co-Authors: Nadezhda Alexeeva, Margarita A. ErbajevaAbstract:Abstract The faunal variations, sedimentary evolution and successive changes in vegetation during the Late Pliocene through the Middle Pleistocene of the Western Transbaikal area were analyzed to ascertain the main events on the Pliocene–Pleistocene boundary and to trace the Early–Middle Pleistocene transition. The evolutionary development of the main characteristic small mammals and their phyletic lineages involved replacement of the Itantsinian fauna by the Dodogolian assemblage. In the West Transbaikalia, the Pliocene–Pleistocene boundary is recognized between the Late Pliocene Itantsinian and the Early Pleistocene Dodogolian faunas. Biostratigraphic studies on small mammals have revealed that the Early–Middle Pleistocene transition can be placed at the Brunhes–Matuyama paleomagnetic boundary (0.78 Ma) which is determined in the middle sequence of the Tologoi key section, between the latest Early Pleistocene fauna of the Tologoi 2.1 and 2.2 and Middle Pleistocene fauna of Tologoi Complex (Tologoi 2.4 and 2.5).
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Pleistocene permafrost in Western Transbaikalia
Quaternary International, 2000Co-Authors: Nadezhda Alexeeva, Margarita A. ErbajevaAbstract:Abstract Progressive cooling of the Pleistocene climate led to the formation of permafrost in the southern part of Eastern Siberia, in particular, in low mountains and valley floors of the Transbaikal area. It was thought that in Western Transbaikalia the permafrost first appeared in the Middle Pleistocene and was related to the maximum — Riss (Samarovo) — glaciation (Ravsky et al., 1964. Anthropogene Deposits of the Southern East Siberia. Nauka Press, Moscow, p. 105 (in Russian); Bazarov, D.B., 1968. The Quaternary Deposits and the Main Stages of the Selenginskoye Midland Development. Ulan-Ude, p. 166 (in Russian); and others). Earlier investigators found evidence of two cold stages in the Tologoi key section (Alexandrova, L.P., Vangengeim, E.A., Gerbova, V.G., Golubeva, L.V., Ravsky, E.I., 1963. New data on the Anthropogene deposits of the Tologoi section (Western Transbaikalia). Quaternary Commission of the USSR, Bulletin 28, 84–101 (in Russian); Bazarov, 1968). New research in this area, in particular, at the Tologoi key section, resulted in the discovery of cryogenic deformation levels which were older than those previously described. They are found below the Brunhes/Matuyama boundary, although above the Jaramillo event of normal magnetization between 0.78 and 0.99 Ma BP. Eight levels of cryogenic deformations have been established in the Tologoi key sections, with three dated to the Early Pleistocene and five to the Middle Pleistocene. In total, in the Transbaikal area, not less than 10 levels of Pleistocene cryogenic deformations are recognized at the present time.
Dale R Guthrie - One of the best experts on this subject based on the ideXlab platform.
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new carbon dates link climatic change with human colonization and Pleistocene extinctions
Nature, 2006Co-Authors: Dale R GuthrieAbstract:The transition from Pleistocene to Holocene between 13,000 and 10,000 years ago was marked by the rapid extinction of many large mammals. The degree to which humans were involved in this has always been a matter of heated debate. Dale Guthrie addresses the issue with an unprecedentedly detailed look at the fauna of Alaska and the Yukon of the period, involving more than 600 radiocarbon dates on the bones of various animal species. Although mammoths and horses became extinct, animals such as the wapiti, bison and moose survived and thrived, suggesting that the faunal change was a function of ecological and vegetational change rather than human-induced ‘overkill’. Radiocarbon data from bones suggests that the faunal change from the transition between Pleistocene and Holocene was a function of ecological and vegetational change rather than human-induced ‘overkill’. Drastic ecological restructuring, species redistribution and extinctions mark the Pleistocene–Holocene transition, but an insufficiency of numbers of well-dated large mammal fossils from this transition have impeded progress in understanding the various causative links1. Here I add many new radiocarbon dates to those already published on late Pleistocene fossils from Alaska and the Yukon Territory (AK–YT) and show previously unrecognized patterns. Species that survived the Pleistocene, for example, bison (Bison priscus, which evolved into Bison bison), wapiti (Cervus canadensis) and, to a smaller degree, moose (Alces alces), began to increase in numbers and continued to do so before and during human colonization and before the regional extinction of horse (Equus ferus) and mammoth (Mammuthus primigenius). These patterns allow us to reject, at least in AK–YT, some hypotheses of late Pleistocene extinction: ‘Blitzkrieg’ version of simultaneous human overkill2, ‘keystone’ removal3, and ‘palaeo-disease’4. Hypotheses of a subtler human impact and/or ecological replacement or displacement are more consistent with the data. The new patterns of dates indicate a radical ecological sorting during a uniquely forage-rich transitional period, affecting all large mammals, including humans.
Jessica L Blois - One of the best experts on this subject based on the ideXlab platform.
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small mammal diversity loss in response to late Pleistocene climatic change
Nature, 2010Co-Authors: Jessica L Blois, Jenny L Mcguire, Elizabeth A HadlyAbstract:The worldwide extinctions of large mammals (megafauna) at the end of the Pleistocene around 10,000 years ago are the stuff of headlines. Did they fall victim to human slaughter or climate change? But what of smaller mammals — rodents, insectivores and the like — which often provide much more comprehensive fossil records than megafauna, and which are much less likely to be the targets of hunting? A study of a rich small-mammal fauna from northern California shows that small mammals were much less likely to respond to the Pleistocene–Holocene transition by becoming extinct. Instead, diversity and evenness suffered, so that less abundant species became rarer, with more generalist 'weed-like' species becoming more common. Many large mammals became extinct worldwide at the end of the Pleistocene epoch, around 12,000 years ago. Here, it is shown that smaller mammals, which often provide much more comprehensive fossil records than large mammals, were much less likely to respond to the Pleistocene–Holocene transition by becoming extinct. Instead, diversity and evenness suffered, so that less abundant species became rarer, with more generalist 'weedy' species becoming more common. Communities have been shaped in numerous ways by past climatic change; this process continues today1. At the end of the Pleistocene epoch about 11,700 years ago, North American communities were substantially altered by the interplay of two events. The climate shifted from the cold, arid Last Glacial Maximum to the warm, mesic Holocene interglacial, causing many mammal species to shift their geographic distributions substantially2,3. Populations were further stressed as humans arrived on the continent4. The resulting megafaunal extinction event, in which 70 of the roughly 220 largest mammals in North America (32%) became extinct5, has received much attention. However, responses of small mammals to events at the end of the Pleistocene have been much less studied, despite the sensitivity of these animals to current and future environmental change. Here we examine community changes in small mammals in northern California during the last ‘natural’ global warming event at the Pleistocene–Holocene transition and show that even though no small mammals in the local community became extinct, species losses and gains, combined with changes in abundance, caused declines in both the evenness and richness of communities. Modern mammalian communities are thus depauperate not only as a result of megafaunal extinctions at the end of the Pleistocene but also because of diversity loss among small mammals. Our results suggest that across future landscapes there will be some unanticipated effects of global change on diversity: restructuring of small mammal communities, significant loss of richness, and perhaps the rising dominance of native ‘weedy’ species.
Nadezhda Alexeeva - One of the best experts on this subject based on the ideXlab platform.
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Changes in the fossil mammal faunas of Western Transbaikalia during the Pliocene–Pleistocene boundary and the Early–Middle Pleistocene transition
Quaternary International, 2005Co-Authors: Nadezhda Alexeeva, Margarita A. ErbajevaAbstract:Abstract The faunal variations, sedimentary evolution and successive changes in vegetation during the Late Pliocene through the Middle Pleistocene of the Western Transbaikal area were analyzed to ascertain the main events on the Pliocene–Pleistocene boundary and to trace the Early–Middle Pleistocene transition. The evolutionary development of the main characteristic small mammals and their phyletic lineages involved replacement of the Itantsinian fauna by the Dodogolian assemblage. In the West Transbaikalia, the Pliocene–Pleistocene boundary is recognized between the Late Pliocene Itantsinian and the Early Pleistocene Dodogolian faunas. Biostratigraphic studies on small mammals have revealed that the Early–Middle Pleistocene transition can be placed at the Brunhes–Matuyama paleomagnetic boundary (0.78 Ma) which is determined in the middle sequence of the Tologoi key section, between the latest Early Pleistocene fauna of the Tologoi 2.1 and 2.2 and Middle Pleistocene fauna of Tologoi Complex (Tologoi 2.4 and 2.5).
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Pleistocene permafrost in Western Transbaikalia
Quaternary International, 2000Co-Authors: Nadezhda Alexeeva, Margarita A. ErbajevaAbstract:Abstract Progressive cooling of the Pleistocene climate led to the formation of permafrost in the southern part of Eastern Siberia, in particular, in low mountains and valley floors of the Transbaikal area. It was thought that in Western Transbaikalia the permafrost first appeared in the Middle Pleistocene and was related to the maximum — Riss (Samarovo) — glaciation (Ravsky et al., 1964. Anthropogene Deposits of the Southern East Siberia. Nauka Press, Moscow, p. 105 (in Russian); Bazarov, D.B., 1968. The Quaternary Deposits and the Main Stages of the Selenginskoye Midland Development. Ulan-Ude, p. 166 (in Russian); and others). Earlier investigators found evidence of two cold stages in the Tologoi key section (Alexandrova, L.P., Vangengeim, E.A., Gerbova, V.G., Golubeva, L.V., Ravsky, E.I., 1963. New data on the Anthropogene deposits of the Tologoi section (Western Transbaikalia). Quaternary Commission of the USSR, Bulletin 28, 84–101 (in Russian); Bazarov, 1968). New research in this area, in particular, at the Tologoi key section, resulted in the discovery of cryogenic deformation levels which were older than those previously described. They are found below the Brunhes/Matuyama boundary, although above the Jaramillo event of normal magnetization between 0.78 and 0.99 Ma BP. Eight levels of cryogenic deformations have been established in the Tologoi key sections, with three dated to the Early Pleistocene and five to the Middle Pleistocene. In total, in the Transbaikal area, not less than 10 levels of Pleistocene cryogenic deformations are recognized at the present time.
Eudald Carbonell - One of the best experts on this subject based on the ideXlab platform.
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The lithic industry of Sima del Elefante (Atapuerca, Burgos, Spain) in the context of Early and Middle Pleistocene technology in Europe
Journal of Human Evolution, 2015Co-Authors: Arturo De Lombera-hermida, Marcos Terradillos-bernal, Josep Vallverdú, Maria Dolores García-antón, Robert Sala, Rosa Huguet, A Ollé, Amèlia Bargalló, Marina Mosquera, Eudald CarbonellAbstract:This paper presents the lithic assemblages documented at Sima del Elefante (TE) and their importance in the context of the Early and Middle Pleistocene human occupation of Europe. We also study changes in human behaviour within the context of the palaeoenvironmental evolution of the Sierra de Atapuerca. This site has characteristics that are of great value for the study of human evolution. The lower levels of TE (Units TE7-TE14) are an essential reference for understanding the early stages of the colonization of Europe. The TE9c level has provided stone tools (Mode 1), faunal remains, and human fossils dated to 1.22Ma (millions of years ago). Moreover, this is one of the few European sites with a stratigraphic sequence that includes remains of human occupations predating the Jaramillo subchron (Early Pleistocene) and from the Late Middle Pleistocene (Units TE18-TE19). Despite this, the presence of archaeologically sterile units (TE15-17) prevents us from establishing a continuous relationship between the Early and Middle Pleistocene human settlements and, consequently, between their technological and behavioural differences. We can, however compare the technological and palaeoeconomic strategies adopted by different species of hominins during two key phases of the occupation of Europe.
