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Pliocene Extinctions
The Pliocene ( ; also Pleiocene) is the epoch in the geologic time scale that extends from 5.333 million to 2.58See the 2014 version of the ICS geologic time scale
million years ago. It is the second and most recent epoch of the Period in the . The Pliocene follows the Epoch and is followed by the



International Commission On Stratigraphy
The International Commission on Stratigraphy (ICS), sometimes referred to unofficially as the "International Stratigraphic Commission", is a daughter or major subcommittee grade scientific daughter organization that concerns itself with stratigraphy, stratigraphical, geology, geological, and chronology, geochronological matters on a global scale. It is the largest subordinate body of the International Union of Geological Sciences (IUGS). The ICS is essentially a permanent working committee, working subcommittee, which meets far more regularly than the quadrennial meetings scheduled by the IUGS, when it meets as a congress or committee, membership of the whole. Aims One of its main aims, a project begun in 1974, is to establish a multidisciplinary standard and global geologic time scale that will ease paleontology, paleontological and geobiology, geobiological comparisons region to region by benchmarks with stringent and rigorous strata criteria called Global Boundary Stratotype ...
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William Whewell
William Whewell ( ; 24 May 17946 March 1866) was an English polymath, scientist, Anglican priest, philosopher, theologian, and historian of science. He was Master of Trinity College, Cambridge. In his time as a student there, he achieved distinction in both poetry and mathematics. The breadth of Whewell's endeavours is his remarkable feature. In a time of increasing specialization, Whewell belonged in an earlier era when natural philosophers investigated widely. He published work in mechanics, physics, geology, astronomy, and economics, while also composing poetry, writing a Bridgewater Treatise, translating the works of Goethe, and writing sermons and theological tracts. In mathematics, Whewell introduced what is now called the Whewell equation, defining the shape of a curve without reference to an arbitrarily chosen coordinate system. He also organized thousands of volunteers internationally to study ocean tides, in what is now considered one of the first citizen scienc ...
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Uquian
The Uquian age is a period of geologic time (3.0–1.5 Ma) within the Pliocene and Pleistocene epochs of the Neogene used more specifically with South American Land Mammal Ages. It follows the Montehermosan and precedes the Ensenadan The Ensenadan age is a period of geologic time (1.2–0.8 Ma) within the Early Pleistocene epoch of the Quaternary The Quaternary ( ) is the current and most recent of the three periods of the Cenozoic Era in the geologic time scale of the ... age. References Pliocene life Piacenzian Neogene South America Quaternary animals of South America {{geochronology-stub ...
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Chapadmalalan
The Chapadmalalan age is a period of geologic time (4.0–3.0 Ma) within the Pliocene epoch of the Neogene used more specifically with South American Land Mammal Ages. It follows the Montehermosan and precedes the Uquian age. Fossil content Fossils of '' Josephoartigasia magna'', a rodent in the family Dinomyidae from this age have been found in southern Uruguay Uruguay (; ), officially the Oriental Republic of Uruguay ( es, República Oriental del Uruguay), is a country in South America. It shares borders with Argentina to its west and southwest and Brazil to its north and northeast; while bordering ....Francis, J. C. & Mones, A. (1966). ''Artigasia magna'' n. g., n. sp. (Eumegamyinae), un roedor gigantesco de la época Pliocena Superior de las Barrancas de San Gregorio, Departamento de San José, República Oriental del Uruguay. ''Kraglieviana'' 3, 89–100. References Neogene South America Pliocene life Piacenzian Zanclean {{geochronology-stub ...
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Montehermosan
The Montehermosan age is a period of geologic time (6.8–4.0 Ma) within the Miocene and Pliocene epochs of the Neogene used more specifically with South American Land Mammal Ages. It follows the Huayquerian and precedes the Chapadmalalan The Chapadmalalan age is a period of geologic time (4.0–3.0 Ma) within the Pliocene epoch of the Neogene used more specifically with South American Land Mammal Ages. It follows the Montehermosan and precedes the Uquian age. Fossil content F ... age. References Miocene life Miocene South America Zanclean Neogene animals of South America {{geochronology-stub ...
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South American Land Mammal Ages
The South American land mammal ages (SALMA) establish a geologic timescale for prehistoric South American fauna beginning 64.5 Ma during the Paleocene and continuing through to the Late Pleistocene (0.011 Ma). These periods are referred to as ages, stages, or intervals and were established using geographic place names where fossil materials where obtained.Flynn & Swisher, 1995 The basic unit of measure is the first/last boundary statement. This shows that the first appearance event of one taxon is known to predate the last appearance event of another. If two taxa are found in the same fossil quarry or at the same stratigraphic horizon, then their age-range zones overlap. Background South America was an island continent for much of the Cenozoic, or the "Age of Mammals". As a result, its mammals evolved in their own unique directions, as Australia and Madagascar still have today. Paleogeographic timeline A simplified paleogeographic timeline of South America: * 66 Ma – Sout ...
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Blancan
The Blancan North American Stage on the geologic timescale is the North American faunal stage according to the North American Land Mammal Ages chronology (NALMA), typically set from 4,750,000 to 1,806,000 years Before Present, BP, a period of . Blancan North American Stage
GeoWhen Database. Version 1.1.0. Retrieved 2017-June-26.
It is usually considered to start in the early-mid Pliocene Epoch and end by the early Pleistocene. The Blancan is preceded by the Hemphillian and followed by the Irvingtonian NALMA stages. As usually defined, it corresponds to the mid-Zanclean through Piacenzian and Gelasian stages in Europe and Asia. In California, the Blancan roughly corresponds to the mid-Delmontian through Repettian and Venturian to the very early Wheelerian. The Austr ...
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Hemphillian
The Hemphillian North American Stage on the geologic timescale is the North American faunal stage according to the North American Land Mammal Ages chronology (NALMA), typically set from 10,300,000 to 4,900,000 years BP. It is usually considered to overlap the Tortonian age of the Late Miocene and Zanclean age of the Early Pliocene. The Hemphillian is preceded by the Clarendonian and followed by the Blancan The Blancan North American Stage on the geologic timescale is the North American faunal stage according to the North American Land Mammal Ages chronology (NALMA), typically set from 4,750,000 to 1,806,000 years Before Present, BP, a period of .
NALMA stages. The Hemphillian can be further divided into the substages of: *Late/Upper Hemphillian: Lower boundary source of the base of the Hemphillian (approximate). *late Early Hemphillian: Lower boundary source of the base of the Hemphillian (approximate). Upper boundary source: base of Blancan (approximat ...
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North American Land Mammal Ages
The North American land mammal ages (NALMA) establishes a geologic timescale for North American fauna beginning during the Late Cretaceous and continuing through to the present. These periods are referred to as ages or intervals (or stages when referring to the rock strata of that age) and were established using geographic place names where fossil materials were obtained. System The North American land-mammal-age system was formalized in 1941 as a series of provincial land-mammal ages. The system was the standard for correlations in the terrestrial Cenozoic record of North America and was the source for similar time scales dealing with other continents. The system was revised into a formal chronostratigraphic system. This approach is nominally justified by international stratigraphic codes; it holds that first appearances of individual species in particular sections are the only valid basis for naming and defining the land-mammal ages. The basic unit of measure is the first/last bo ...
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Zanclean
The Zanclean is the lowest stage or earliest age on the geologic time scale of the Pliocene. It spans the time between 5.332 ± 0.005 Ma (million years ago) and 3.6 ± 0.005 Ma. It is preceded by the Messinian Age of the Miocene Epoch, and followed by the Piacenzian Age. The Zanclean can be correlated with regionally used stages, such as the Opoitian of New Zealand, and the Tabianian or Dacian of Central Europe. It also corresponds to the late Hemphillian to mid-Blancan North American Land Mammal Ages. In California, the Zanclean roughly corresponds to the middle part of the Delmontian stage. Definition The Zanclean Stage was introduced by Giuseppe Seguenza in 1868. It is named after ''Zancle'', the pre-Roman name for the Italian city of Messina on Sicily. The base of the Zanclean (and the Pliocene Series) lies with the top of magnetic chronozone Cr3 (about 100,000 years before the Thvera normal subchronozone C3n.4n). The base is also close to the extinction level of the calc ...
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Piacenzian
The Piacenzian is in the international geologic time scale the upper stage (stratigraphy), stage or latest age (geology), age of the Pliocene. It spans the time between 3.6 ± 0.005 year#SI prefix multipliers, Ma and 2.588 ± 0.005 Ma (million years ago). The Piacenzian is after the Zanclean and is followed by the Gelasian (part of the Pleistocene). The Piacenzian is roughly coeval with the European land mammal age MN 16, overlaps the late Chapadmalalan and early Uquian South American land mammal age and falls inside the more extensive Blancan North American land mammal age. It also correlates with the Astian, Redonian, Reuverian and Romanian regional stages of Europe. Some authorities describe the British Red Crag Formation and Waltonian Stage as late Piacenzian, while others regard them as early Pleistocene. Carbon dioxide levels during the Piacenzian were similar to those of today, making this age, with global mean temperature 2–3 °C higher and sea levels about twenty meters ...
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Stage (stratigraphy)
In chronostratigraphy, a stage is a succession of rock strata laid down in a single age on the geologic timescale, which usually represents millions of years of deposition. A given stage of rock and the corresponding age of time will by convention have the same name, and the same boundaries. Rock series are divided into stages, just as geological epochs are divided into ages. Stages can be divided into smaller stratigraphic units called chronozones. (See chart at right for full terminology hierarchy.) Stages may also be divided into substages or indeed grouped as superstages. The term faunal stage is sometimes used, referring to the fact that the same fauna (animals) are found throughout the layer (by definition). Definition Stages are primarily defined by a consistent set of fossils (biostratigraphy) or a consistent magnetic polarity (see paleomagnetism) in the rock. Usually one or more index fossils that are common, found worldwide, easily recognized, and limited to a sing ...
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