|
Pleistocene Megafauna
Pleistocene megafauna is the set of large animals that lived on Earth during the Pleistocene epoch. Pleistocene megafauna became extinct during the Quaternary extinction event resulting in substantial changes to ecosystems globally. The role of humans in causing Pleistocene megafaunal extinctions is controversial. Megafauna are any animals with an adult body weight of over . Pleistocene megafauna include the straight-tusked elephant, cave bear (''Ursus spelaeus''), interglacial rhinoceros (''Stephanorhinus''), heavy-bodied Asian antelope ('' Spirocerus''), Eurasian hippopotamuses, woolly rhinoceros, mammoths, giant deer, sabre-toothed cat (''Homotherium''), cave lion, and the leopard in Europe. Paleoecology The last glacial period, commonly referred to as the 'Ice Age', spanned 125,000 to 14,500 years ago and was the most recent glacial period within the current ice age which occurred during the final years of the Pleistocene epoch. The Ice Age reached its peak during the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ice Age Fauna Of Northern Spain - Mauricio Antón
Ice is water frozen into a solid state, typically forming at or below temperatures of 0 degrees Celsius or Depending on the presence of impurities such as particles of soil or bubbles of air, it can appear transparent or a more or less opaque bluish-white color. In the Solar System The Solar SystemCapitalization of the name varies. The International Astronomical Union, the authoritative body regarding astronomical nomenclature, specifies capitalizing the names of all individual astronomical objects but uses mixed "Solar S ..., ice is abundant and occurs naturally from as close to the Sun as Mercury (planet), Mercury to as far away as the Oort cloud objects. Beyond the Solar System, it occurs as interstellar ice. It is abundant on Earth's surfaceparticularly Polar ice cap, in the polar regions and above the snow lineand, as a common form of precipitation and Deposition (phase transition), deposition, plays a key role in Earth's water cycle and climate. It falls as snowfl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Siberia
Siberia ( ; rus, Сибирь, r=Sibir', p=sʲɪˈbʲirʲ, a=Ru-Сибирь.ogg) is an extensive geographical region, constituting all of North Asia, from the Ural Mountains in the west to the Pacific Ocean in the east. It has been a part of Russia since the latter half of the 16th century, after the Russians conquered lands east of the Ural Mountains. Siberia is vast and sparsely populated, covering an area of over , but home to merely one-fifth of Russia's population. Novosibirsk, Krasnoyarsk and Omsk are the largest cities in the region. Because Siberia is a geographic and historic region and not a political entity, there is no single precise definition of its territorial borders. Traditionally, Siberia extends eastwards from the Ural Mountains to the Pacific Ocean, and includes most of the drainage basin of the Arctic Ocean. The river Yenisey divides Siberia into two parts, Western and Eastern. Siberia stretches southwards from the Arctic Ocean to the hills of north-ce ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Yana Rhinoceros Horn Site
The Yana Rhinoceros Horn Site (Yana RHS) is an Upper Palaeolithic archaeological site located near the lower Yana river in northeastern Siberia, Russia, north of the Arctic Circle in the far west of Beringia. It was discovered in 2001, after thawing and erosion exposed animal bones and artifacts. The site features a well-preserved cultural layer due to the cold conditions, and includes hundreds of animal bones and ivory pieces and numerous artifacts, which are indicative of sustained settlement and a relatively high level of technological development. With an estimated age of around 32,000 calibrated years before present, the site provides the earliest archaeological evidence for human settlement in this region, or anywhere north of the Arctic Circle, where people survived extreme conditions and hunted a wide range of fauna before the onset of the Last Glacial Maximum. The Yana site is perhaps the earliest unambiguous evidence of mammoth hunting by humans. A 2019 study found that ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Early Human Migrations
Early human migrations are the earliest migrations and expansions of archaic and modern humans across continents. They are believed to have begun approximately 2 million years ago with the early expansions out of Africa by '' Homo erectus''. This initial migration was followed by other archaic humans including '' H. heidelbergensis'', which lived around 500,000 years ago and was the likely ancestor of Denisovans and Neanderthals as well as modern humans. Early hominids had likely crossed land bridges that have now sunk. Within Africa, '' Homo sapiens'' dispersed around the time of its speciation, roughly 300,000 years ago. The recent African origin paradigm suggests that the anatomically modern humans outside of Africa descend from a population of ''Homo sapiens'' migrating from East Africa roughly 70–50,000 years ago and spreading along the southern coast of Asia and to Oceania by about 50,000 years ago. Modern humans spread across Europe about 40,000 years ago. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Genus
Genus ( plural genera ) is a taxonomic rank used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In the hierarchy of biological classification, genus comes above species and below family (taxonomy), family. In binomial nomenclature, the genus name forms the first part of the binomial species name for each species within the genus. :E.g. ''Panthera leo'' (lion) and ''Panthera onca'' (jaguar) are two species within the genus ''Panthera''. ''Panthera'' is a genus within the family Felidae. The composition of a genus is determined by taxonomy (biology), taxonomists. The standards for genus classification are not strictly codified, so different authorities often produce different classifications for genera. There are some general practices used, however, including the idea that a newly defined genus should fulfill these three criteria to be descriptively useful: # monophyly – all descendants ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Wrangel Island
Wrangel Island ( rus, О́стров Вра́нгеля, r=Ostrov Vrangelya, p=ˈostrəf ˈvrangʲɪlʲə; ckt, Умӄиԓир, translit=Umqiḷir) is an island of the Chukotka Autonomous Okrug, Russia. It is the 91st largest island in the world and roughly the size of Crete. Located in the Arctic Ocean between the Chukchi Sea and East Siberian Sea, the island lies astride the 180th meridian. The International Date Line is therefore displaced eastwards at this latitude to avoid the island as well as the Chukchi Peninsula on the Russian mainland, to keep the island on the same day as the rest of Russia. The closest land to Wrangel Island is the tiny and rocky Herald Island located to the east.Kosko, M.K., M.P. Cecile, J.C. Harrison, V.G. Ganelin, N.V., Khandoshko, and B.G. Lopatin, 1993Geology of Wrangel Island, Between Chukchi and East Siberian Seas, Northeastern Russia.Bulletin 461, Geological Survey of Canada, Ottawa Ontario, 101 pp. Wrangel Island is the last known pla ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Wisconsin Glaciation
The Wisconsin Glacial Episode, also called the Wisconsin glaciation, was the most recent glacial period of the North American ice sheet complex. This advance included the Cordilleran Ice Sheet, which nucleated in the northern North American Cordillera; the Innuitian ice sheet, which extended across the Canadian Arctic Archipelago; the Greenland ice sheet; and the massive Laurentide Ice Sheet, which covered the high latitudes of central and eastern North America. This advance was synchronous with global glaciation during the last glacial period, including the North American alpine glacier advance, known as the Pinedale glaciation. The Wisconsin glaciation extended from approximately 75,000 to 11,000 years ago, between the Sangamonian Stage and the current interglacial, the Holocene. The maximum ice extent occurred approximately 25,000–21,000 years ago during the last glacial maximum, also known as the ''Late Wisconsin'' in North America. This glaciation radically altered the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bering Land Bridge
Beringia is defined today as the land and maritime area bounded on the west by the Lena River in Russia; on the east by the Mackenzie River in Canada; on the north by 72 degrees north latitude in the Chukchi Sea; and on the south by the tip of the Kamchatka Peninsula. It includes the Chukchi Sea, the Bering Sea, the Bering Strait, the Chukchi Peninsula, Chukchi and Kamchatka Peninsulas in Russia as well as Alaska in the United States and the Yukon in Canada. The area includes land lying on the North American Plate and Siberian land east of the Chersky Range. At certain times in prehistory, it formed a land bridge that was up to wide at its greatest extent and which covered an area as large as British Columbia and Alberta together, totaling approximately . Today, the only land that is visible from the central part of the Bering land bridge are the Diomede Islands, the Pribilof Islands of St. Paul and St. George, St. Lawrence Island, St. Matthew Island, and King Island (Alaska), ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mammoth Steppe
During the Last Glacial Maximum, the mammoth steppe, also known as steppe-tundra, was the Earth's most extensive biome. It spanned from Spain eastward across Eurasia to Canada and from the List of islands in the Arctic Ocean, arctic islands southward to China. The mammoth steppe was cold and dry. The vegetation was dominated by palatable high-productivity grasses, herbs and willow shrubs. The animal biomass was dominated by reindeer, bison, Equus (genus), horses, and woolly mammoth. This ecosystem covered wide areas of the northern part of the globe, thrived for approximately 100,000 years without major changes, but then diminished to small regions around 12,000 years ago. Naming At the end of the 19th century, Alfred Nehring (1890) and Jan Czerski (Iwan Dementjewitsch Chersky, 1891) proposed that during the last glacial period a major part of northern Europe had been populated by large herbivores and that a steppe climate had prevailed there. In 1982, the scientist R. Dale Gut ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Before Present
Before Present (BP) years, or "years before present", is a time scale used mainly in archaeology, geology and other scientific disciplines to specify when events occurred relative to the origin of practical radiocarbon dating in the 1950s. Because the "present" time changes, standard practice is to use 1 January 1950 as the commencement date (epoch) of the age scale. The abbreviation "BP" has been interpreted retrospectively as "Before Physics", which refers to the time before nuclear weapons testing artificially altered the proportion of the carbon isotopes in the atmosphere, which scientists must now account for. In a convention that is not always observed, many sources restrict the use of BP dates to those produced with radiocarbon dating; the alternative notation RCYBP stands for the explicit "radio carbon years before present". Usage The BP scale is sometimes used for dates established by means other than radiocarbon dating, such as stratigraphy. This usage differs from t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ice Sheet
In glaciology, an ice sheet, also known as a continental glacier, is a mass of glacial ice that covers surrounding terrain and is greater than . The only current ice sheets are in Antarctica and Greenland; during the Last Glacial Period at Last Glacial Maximum, the Laurentide Ice Sheet covered much of North America, the Weichselian ice sheet covered Northern Europe and the Patagonian Ice Sheet covered southern South America. Ice sheets are bigger than ice shelves or alpine glaciers. Masses of ice covering less than 50,000 km2 are termed an ice cap. An ice cap will typically feed a series of glaciers around its periphery. Although the surface is cold, the base of an ice sheet is generally warmer due to geothermal heat. In places, melting occurs and the melt-water lubricates the ice sheet so that it flows more rapidly. This process produces fast-flowing channels in the ice sheet — these are ice streams. The present-day polar ice sheets are relatively young in geol ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
