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Articles 101 à 120 sur 679
Par R. Dale Guthrie. 1990
Frozen mammals of the Ice Age, preserved for millennia in the tundra, have been a source of fascination and mystery…
since their first discovery over two centuries ago. These mummies, their ecology, and their preservation are the subject of this compelling book by paleontologist Dale Guthrie. The 1979 find of a frozen, extinct steppe bison in an Alaskan gold mine allowed him to undertake the first scientific excavation of an Ice Age mummy in North America and to test theories about these enigmatic frozen fauna. The 36,000-year-old bison mummy, coated with blue mineral crystals, was dubbed "Blue Babe. " Guthrie conveys the excitement of its excavation and shows how he made use of evidence from living animals, other Pleistocene mummies, Paleolithic art, and geological data. With photographs and scores of detailed drawings, he takes the reader through the excavation and subsequent detective work, analyzing the animal's carcass and its surroundings, the circumstances of its death, its appearance in life, the landscape it inhabited, and the processes of preservation by freezing. His examination shows that Blue Babe died in early winter, falling prey to lions that inhabited the Arctic during the Pleistocene era. Guthrie uses information gleaned from his study of Blue Babe to provide a broad picture of bison evolutionary history and ecology, including speculations on the interactions of bison and Ice Age peoples. His description of the Mammoth Steppe as a cold, dry, grassy plain is based on an entirely new way of reading the fossil record.Par Kaarina Weckstr m, Krystyna Saunders, Peter Gell, C Skilbeck. 2017
The aim of this edited volume is to introduce the scientific community to paleoenvironmental studies of estuaries, to highlight the…
types of information that can be obtained from such studies, and to promote the use of paleoenvironmental studies in estuarine management. Readers will learn about the the application of different paleoecological approaches used in estuaries that develop our understanding of their response to natural and human influences. Particular attention is given to the essential steps required for undertaking a paleoecological study, in particular with regard to site selection, core extraction and chronological techniques, followed by the range of indicators that can be used. A series of case studies are discussed in the book to demonstrate how paleoecological studies can be used to address key questions, and to sustainably manage these important coastal environments in the future. This book will appeal to professional scientists interested in estuarine studies and/or paleoenvironmental research, as well as estuarine managers who are interested in the incorporation of paleoenvironmental research into their management programs.Par Michael Woodburne, Francisco Goin, Ana Zimicz, Gabriel Martin, Laura Chornogubsky. 2016
This book summarizes major aspects of the evolution of South American metatherians, including their epistemologic, phylogenetic, biogeographic, faunal, tectonic, paleoclimatic,…
and metabolic contexts. A brief overview of the evolution of each major South American lineage ("Ameridelphia", Sparassodonta, Didelphimorphia, Paucituberculata, Microbiotheria, and Polydolopimorphia) is provided. It is argued that due to physiological constraints, metatherian evolution closely followed the conditions imposed by global temperatures. In general terms, during the Paleocene and the early Eocene multiple radiations of metatherian lineages occurred, with many adaptive types exploiting insectivorous, frugivorous, and omnivorous adaptive zones. In turn, a mixture of generalized and specialized types, the latter mainly exploiting carnivorous and granivorous-folivorous adaptive zones, characterized the second half of the Cenozoic. In both periods, climate was the critical driver of their radiation and turnovers.Par Michael O. Woodburne, Francisco J. Goin, Ana Natalia Zimicz, Gabriel M. Martin, Laura Chornogubsky. 2016
This book summarizes major aspects of the evolution of South American metatherians, including their epistemologic, phylogenetic, biogeographic, faunal, tectonic, paleoclimatic,…
and metabolic contexts. A brief overview of the evolution of each major South American lineage ("Ameridelphia", Sparassodonta, Didelphimorphia, Paucituberculata, Microbiotheria, and Polydolopimorphia) is provided. It is argued that due to physiological constraints, metatherian evolution closely followed the conditions imposed by global temperatures. In general terms, during the Paleocene and the early Eocene multiple radiations of metatherian lineages occurred, with many adaptive types exploiting insectivorous, frugivorous, and omnivorous adaptive zones. In turn, a mixture of generalized and specialized types, the latter mainly exploiting carnivorous and granivorous-folivorous adaptive zones, characterized the second half of the Cenozoic. In both periods, climate was the critical driver of their radiation and turnovers.Par Michael Woodburne, Francisco Goin, Ana Zimicz, Gabriel Martin, Laura Chornogubsky. 2016
This book summarizes major aspects of the evolution of South American metatherians, including their epistemologic, phylogenetic, biogeographic, faunal, tectonic, paleoclimatic,…
and metabolic contexts. A brief overview of the evolution of each major South American lineage ("Ameridelphia", Sparassodonta, Didelphimorphia, Paucituberculata, Microbiotheria, and Polydolopimorphia) is provided. It is argued that due to physiological constraints, metatherian evolution closely followed the conditions imposed by global temperatures. In general terms, during the Paleocene and the early Eocene multiple radiations of metatherian lineages occurred, with many adaptive types exploiting insectivorous, frugivorous, and omnivorous adaptive zones. In turn, a mixture of generalized and specialized types, the latter mainly exploiting carnivorous and granivorous-folivorous adaptive zones, characterized the second half of the Cenozoic. In both periods, climate was the critical driver of their radiation and turnovers.Par Michael Woodburne, Francisco Goin, Ana Zimicz, Gabriel Martin, Laura Chornogubsky. 2016
This book summarizes major aspects of the evolution of South American metatherians, including their epistemologic, phylogenetic, biogeographic, faunal, tectonic, paleoclimatic,…
and metabolic contexts. A brief overview of the evolution of each major South American lineage ("Ameridelphia", Sparassodonta, Didelphimorphia, Paucituberculata, Microbiotheria, and Polydolopimorphia) is provided. It is argued that due to physiological constraints, metatherian evolution closely followed the conditions imposed by global temperatures. In general terms, during the Paleocene and the early Eocene multiple radiations of metatherian lineages occurred, with many adaptive types exploiting insectivorous, frugivorous, and omnivorous adaptive zones. In turn, a mixture of generalized and specialized types, the latter mainly exploiting carnivorous and granivorous-folivorous adaptive zones, characterized the second half of the Cenozoic. In both periods, climate was the critical driver of their radiation and turnovers.Par Neal S. Gupta. 2014
This book provides an overview, research compendium and an introduction to the science of molecular paleontology, including literature overview for…
non-geochemists. Analytical methods employed are included as a part of each chapter that underpin this branch of paleontology and indeed geochemistry. The primary usefulness of this volume is for organic geochemists, molecular palaeontologists, and molecular archeologists. Researchers, graduate students and academics interested in astrobiology from a paleontological perspective may also find this to be valuable.Par Peter Andrews, Yolanda Fernández-Jalvo. 2016
The aim of the atlas is to provide images of taphonomic modifications, making it as comprehensive as possible with evidence…
presently available. This volume is intended both as a field guide for identifying taphonomic modifications in the field, and for use in the laboratory when collections of fossils are being analyzed. Images in the book are a combination of scanning electron micrographs, regular photographs, cross-sections of bones and line drawings and graphs. By providing good quality illustrations of taphonomic modifications, with links between similar types of modification, the atlas provides a reference source for identifying the agents responsible for the modifications, the processes by which they were formed, and the potential bias introduced by the processes. The authors also aim to emphasize on the directions they consider taphonomic studies should be headed. Firstly, we should seek to quantify the degree of bias introduced into a fossil fauna and to take account of this bias before interpreting the palaeoecology of the fossil site. Secondly, we should recognize that taphonomic modifications increase the information encoded in fossils by identifying perimortem and postmortem context s. This provides a more dynamic and realistic view of the past.Par Peter Andrews, Yolanda Fern ndez. 2016
The aim of the atlas is to provide images of taphonomic modifications, making it as comprehensive as possible with evidence…
presently available. This volume is intended both as a field guide for identifying taphonomic modifications in the field, and for use in the laboratory when collections of fossils are being analyzed. Images in the book are a combination of scanning electron micrographs, regular photographs, cross-sections of bones and line drawings and graphs. By providing good quality illustrations of taphonomic modifications, with links between similar types of modification, the atlas provides a reference source for identifying the agents responsible for the modifications, the processes by which they were formed, and the potential bias introduced by the processes. The authors also aim to emphasize on the directions they consider taphonomic studies should be headed. Firstly, we should seek to quantify the degree of bias introduced into a fossil fauna and to take account of this bias before interpreting the palaeoecology of the fossil site. Secondly, we should recognize that taphonomic modifications increase the information encoded in fossils by identifying perimortem and postmortem context s. This provides a more dynamic and realistic view of the past.Par Sergio Mart nez, Claudia J del R o, Alejandra Rojas. 2012
The Quaternary comprises a brief time in the Earth's history, and apart from a few exceptions, molluscan assemblages recovered from…
exposures along the coast of Southwestern South America (Southern Brazil, Uruguay, Argentina) are essentially the same than those that inhabit the region today, leading to the assumption that no important change in the distribution of the faunas since Pleistocene times has occurred. However, the good taxonomic and temporal resolution reached in the last years, allowed us to detect some biogeographic changes, although traditional biogeographic units remain the same (i.e. Magellanic and Argentinean Provinces). These modifications involve mainly variations in the taxonomic composition of the assemblages and in the southern boundaries of some species distributions (extralimital species), today retracted northwards. These changes are related to southward shifts of the warm waters of the Brazilian Current, correlated with global warm peaks. This phenomenon was more intense in the Late Pleistocene (MIS 5e) and in the Holocene between ca. 6500-3500 14C yr.Par Juan Ponce, Maril n Fern ndez. 2014
This book is the result of ten years' of scientific research carried out by the authors on Isla de los…
Estados. The research includes their doctoral thesis and many published scientific papers related to the island. The book is divided into two principal parts. The first part covers different social and natural aspects of this remote island and includes chapters on the scientific and historical background, physiography with topographical and hydrographical descriptions, climate and oceanographic circulation, vegetation and geology (including stratigraphy, structural geology and geological history). The second part comprises a reconstruction of the paleoenvironmental, paleoclimatic and paleogeographic history of the island from the Last Glacial Maximum to the present, correlating with other paleoecological records from the southern part of Isla Grande de Tierra del Fuego and Patagonia. This second part also includes a geomorphological chapter with a characterization of the principal erosive glacial landforms on Isla de los Estados constructed by means of morphometric analysis, inventories, maps, paleogeographic and glacial models, and a paleoecological chapter evaluating the palaeoenvironment and palaeoclimatic conditions that prevailed during the Late Pleistocene-Holocene times based on pollen and diatom analysis from three 14C-dated peat bogs and lakes. Finally, the book concludes with a review of the island's archaeology and the relationship between the palaeoenvironmental history and human occupation of this island.Par Juan Federico Ponce, Marilén Fernández. 2014
This book is the result of ten years' of scientific research carried out by the authors on Isla de los…
Estados. The research includes their doctoral thesis and many published scientific papers related to the island. The book is divided into two principal parts. The first part covers different social and natural aspects of this remote island and includes chapters on the scientific and historical background, physiography with topographical and hydrographical descriptions, climate and oceanographic circulation, vegetation and geology (including stratigraphy, structural geology and geological history). The second part comprises a reconstruction of the paleoenvironmental, paleoclimatic and paleogeographic history of the island from the Last Glacial Maximum to the present, correlating with other paleoecological records from the southern part of Isla Grande de Tierra del Fuego and Patagonia. This second part also includes a geomorphological chapter with a characterization of the principal erosive glacial landforms on Isla de los Estados constructed by means of morphometric analysis, inventories, maps, paleogeographic and glacial models, and a paleoecological chapter evaluating the palaeoenvironment and palaeoclimatic conditions that prevailed during the Late Pleistocene-Holocene times based on pollen and diatom analysis from three 14C-dated peat bogs and lakes. Finally, the book concludes with a review of the island's archaeology and the relationship between the palaeoenvironmental history and human occupation of this island.Although consensus exists among researchers that birds evolved from coelurosaurian theropods, paleontologists still debate the identification of the group of…
coelurosaurians that most closely approaches the common ancestor of birds. The last 20 years witnessed the discovery of a wide array of avian-like theropods that has considerably amplified the anatomical disparity among deinonychosaurians, some of which resemble Archaeopteryx more than Deinonychus. Among these newly discovered theropods that show remarkable bird-like characteristics are the four-winged theropods Microraptor and Anchiornis, and the unenlagiids Unenlagia, Buitreraptor, and Rahonavis. A bizarre group of minute-sized coelurosaurs, the Scansoriopterygidae, also exhibits some avian similarities that lead some authors to interpret them as more closely related to birds than other dinosaurs. With the aim to explore the phylogenetic relationships of these coelurosaurians and birds, we merged recently published integrative databases, resulting in significant changes in the topological distribution of taxa within Paraves. We present evidence that Dromaeosauridae, Microraptoria, Unenlagiidae, and Anchiornis + Xiaotingia form successive sister taxa of Aves, and that the Scansoriopterygidae are basal coelurosaurians not closely related to birds. The implications in the evolutionary sequence of anatomical characters leading to birds, including the origin of flight, are also considered in light of this new phylogenetic hypothesis.Par Joseph Seckbach, Joan M. Bernhard, Alexander Altenbach. 2011
ANOXIA defines the lack of free molecular oxygen in an environment. In the presence of organic matter, anaerobic prokaryotes produce…
compounds such as free radicals, hydrogen sulfide, or methane that are typically toxic to aerobes. The concomitance of suppressed respiration and presence of toxic substances suggests these habitats are inhospitable to Eukaryota. Ecologists sometimes term such environments 'Death Zones'. This book presents, however, a collection of remarkable adaptations to anoxia, observed in Eukaryotes such as protists, animals, plants and fungi. Case studies provide evidence for controlled beneficial use of anoxia by, for example, modification of free radicals, use of alternative electron donors for anaerobic metabolic pathways, and employment of anaerobic symbionts. The complex, interwoven existence of oxic and anoxic conditions in space and time is also highlighted as is the idea that eukaryotic inhabitation of anoxic habitats was established early in Earth history.Par Gerd-Christian Weniger, Silvana Condemi. 2010
Since the Western world first became aware of the existence of Neanderthals, this Pleistocene human has been a regular focus…
of interest among specialists and also among the general public. In fact, we know far more about Neanderthals than we do about any other extinct human population. Furthermore, over the past 150 years no other palaeospecies has been such a constant source of discussion and fierce debate among palaeoanthropologists and archaeologists. This book presents the status of our knowledge as well as the methods and techniques used to study this extinct population and it suggests perspectives for future research.Par Bernhard M. Riegl, Gregor P. Eberli, Hildegard Westphal. 2009
Carbonate sediments are of increasing relevance for archives of past environmental conditions and for economical reasons in areas of geothermal…
energy and hydrocarbon reservoirs. Complex interaction of physical and chemical parameters with biological parameters determines the architecture and composition of carbonate sedimentary bodies. This book closes some of the still existing gaps in our understanding of the influence and interplay of physical, chemical, and biological parameters with carbonate sedimentation. An understanding of this interaction is not only required for reliable prediction of reservoir quality but also for a robust interpretation of environmental conditions in the past and the present. It is written by geologists for geologists in order to provide an easily accessible overview of the large amount of relevant information provided by the neighbouring sciences. The approach of the book is to document the modern depositional environments of three classical areas of carbonate deposition, each characteristic for a specific sedimentological setting (isolated platform, attached shelf, ramp) in order to assess both the range of physical, biological and chemical parameters and their sedimentary response. This book presents a comprehensive compilation based on data from published work and unpublished theses, and the integration of these data in order to extract previously undiscovered relationships between the discussed parameters and carbonate deposition.Par Bernhard Riegl, Gregor Eberli, Hildegard Westphal. 2009
Carbonate sediments are of increasing relevance for archives of past environmental conditions and for economical reasons in areas of geothermal…
energy and hydrocarbon reservoirs. Complex interaction of physical and chemical parameters with biological parameters determines the architecture and composition of carbonate sedimentary bodies. This book closes some of the still existing gaps in our understanding of the influence and interplay of physical, chemical, and biological parameters with carbonate sedimentation. An understanding of this interaction is not only required for reliable prediction of reservoir quality but also for a robust interpretation of environmental conditions in the past and the present. It is written by geologists for geologists in order to provide an easily accessible overview of the large amount of relevant information provided by the neighbouring sciences. The approach of the book is to document the modern depositional environments of three classical areas of carbonate deposition, each characteristic for a specific sedimentological setting (isolated platform, attached shelf, ramp) in order to assess both the range of physical, biological and chemical parameters and their sedimentary response. This book presents a comprehensive compilation based on data from published work and unpublished theses, and the integration of these data in order to extract previously undiscovered relationships between the discussed parameters and carbonate deposition.Par Luca Basilone. 2018
This book offers as comprehensive an overview as possible of the lithostratigraphy of the Italian region of Sicily, taking into…
account the multiplicity of formational and terminological variability developed over more than a century of studies and publications. It presents stratigraphic terminology, the geological lexicon and the main stratigraphic subdivisions that are not familiar to Sicilian geologists. The new stratigraphic methods and the use of formations as mapping units have prompted the acquisition of new lithostratigraphic data, and a review of the previous units and their comparison with the new collected data, enabling the definition of a number of new lithostratigraphic units. The book summarizes the results in 77 worksheets containing the most important information regarding the lithological, sedimentological and microfacies characteristics, the measured thicknesses, areal extent and the regional aspects, the paleoenvironmental, paleogeographic and paleo-tectonics setting, compiled according to standard procedures and nomenclature rules provided by the International Commission on Stratigraphy (ICS).Par John J. McKay. 2018
The fascinating saga of solving the mystery of this ancient animal who once roamed the north country—and has captivated our…
collective imagination ever since. Today, we know that a mammoth is an extinct type of elephant that was covered with long fur and lived in the north country during the ice ages. But how do you figure out what a mammoth is if you have no concept of extinction, ice ages, or fossils? Long after the last mammoth died and was no longer part of the human diet, it still played a role in human life. Cultures around the world interpreted the remains of mammoths through the lens of their own worldview and mythology. When the ancient Greeks saw deposits of giant fossils, they knew they had discovered the battle fields where the gods had vanquished the Titans. When the Chinese discovered buried ivory, they knew they had found dragons’ teeth. But as the Age of Reason dawned, monsters and giants gave way to the scientific method. Yet the mystery of these mighty bones remained. How did Enlightenment thinkers overcome centuries of myth and misunderstanding to reconstruct an unknown animal? The journey to unravel that puzzle begins in the 1690s with the arrival of new type of ivory on the European market bearing the exotic name "mammoth." It ends during the Napoleonic Wars with the first recovery of a frozen mammoth. The path to figuring out the mammoth was traveled by merchants, diplomats, missionaries, cranky doctors, collectors of natural wonders, Swedish POWs, Peter the Great, Ben Franklin, the inventor of hot chocolate, and even one pirate. McKay brings together dozens of original documents and illustrations, some ignored for centuries, to show how this odd assortment of characters solved the mystery of the mammoth and, in doing so, created the science of paleontology.Par Krish Seetah. 2019
In this book, Krish Seetah uses butchery as a point of departure for exploring the changing historical relationships between animal…
utility, symbolism, and meat consumption. Seetah brings together several bodies of literature - on meat, cut marks, craftspeople, and the role of craft in production - that have heretofore been considered in isolation from one another. Focusing on the activity inherent in butcher, he describes the history of knowledge that typifies the craft. He also provides anthropological and archaeological case studies which showcase examples of butchery practices in varied contexts that are seldom identified with zooarchaeological research. Situating the relationship between practice, practitioner, material and commodity, this imaginative study offers new insights into food production, consumption, and the craft of cuisine.