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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 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 Epoch and end by the early . The Blancan is preceded by the Hemphill ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 The Clarendonian 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 13,600,000 to 10,300,000 years BP, a period of . It is ... and followed by the Blancan 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 (approximate). *early Early ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pliocene
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 Cenozoic Era. The Pliocene follows the Miocene Epoch and is followed by the Pleistocene Epoch. Prior to the 2009 revision of the geologic time scale, which placed the fou ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Irvingtonian
The Irvingtonian North American Land Mammal Age on the geologic timescale is the North American faunal stage according to the North American Land Mammal Ages chronology (NALMA), spanning from 1.9 million – 250,000 years BP.The _Blancan, Irvingtonian and Rancholabrean Mammal Ages by Christopher J. Bell and Ernest L. Lundelius Jr., Anthony D. Barnosky, Russell W. Graham, Everett H. Lindsay, Dennis R. Ruez Jr., Holmes A. Semken Jr., S. David Webb, and Richard J. Zakrzewski. January 2004 in the book: Late Cretaceous and Cenozoic Mammals of North America: Biostratigraphy and Geochronology. Chapter: 7. Publisher: Columbia University Press; Editors: Michael O. Woodburne. pp274-276 Named after an assemblage of fossils from the [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pleistocene
The Pleistocene ( , often referred to as the '' Ice age'') is the geological epoch that lasted from about 2,580,000 to 11,700 years ago, spanning the Earth's most recent period of repeated glaciations. Before a change was finally confirmed in 2009 by the International Union of Geological Sciences, the cutoff of the Pleistocene and the preceding Pliocene was regarded as being 1.806 million years Before Present (BP). Publications from earlier years may use either definition of the period. The end of the Pleistocene corresponds with the end of the last glacial period and also with the end of the Paleolithic age used in archaeology. The name is a combination of Ancient Greek grc, label=none, πλεῖστος, pleīstos, most and grc, label=none, καινός, kainós (latinized as ), 'new'. At the end of the preceding Pliocene, the previously isolated North and South American continents were joined by the Isthmus of Panama, causing a faunal interchange between the t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Piacenzian
The Piacenzian is in the international geologic time scale the upper stage or latest age of the Pliocene. It spans the time between 3.6 ± 0.005 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 higher than today, an important analogue for predictions of the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Suchian (faunal Age)
The Suchian was a faunal age of Japan, lasting from 3 to 1.9 million years ago, at the boundary of the Pliocene and Pleistocene epochs. It corresponds in age to the latter part of the Blancan of North America, and to most of the Piacenzian and Gelasian The Gelasian is an age in the international geologic timescale or a stage in chronostratigraphy, being the earliest or lowest subdivision of the Quaternary Period/System and Pleistocene Epoch/Series. It spans the time between 2.58 Ma (million ye ... of Europe. References {{geochronology-stub Geochronology ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Paenemarmota
''Paenemarmota'' is an extinct genus of ground squirrel from North America. Fossils are known from the Blancan and Hemphillian age from localities in Nebraska, Kansas, Texas, Arizona, and Mexico. At around the size of a beaver, ''Paenemarmota'' is the largest known member of the squirrel family. Description ''Paenemarmota'' is the largest known ground squirrel and is nearly twice as large as the largest living marmots. Weight estimates for ''P. barbouri'' are around on the basis of femur dimensions, or up to kg on the basis of lengths of premolars. On the basis of lengths of premolars, ''P. mexicana'' may have weighed up to , while ''P. sawrockensis'' was smaller, at up to . Although some of its features are primitive, in general morphology it resembles the ground squirrels of the genus ''Spermophilus ''Spermophilus'' is a genus of ground squirrels in the squirrel family. As traditionally defined the genus was very species-rich, ranging through Europe, Asia and North ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nukumaruan
While also using the international geologic time scale, many nations–especially those with isolated and therefore non-standard prehistories–use their own systems of dividing geologic time into epochs and faunal stages. In New Zealand, these epochs and stages use local place names (mainly Māori in origin) back to the Permian. Prior to this time, names mostly align to those in the Australian geologic time scale, and are not divided into epochs. In practice, these earlier terms are rarely used, as most New Zealand geology is of a more recent origin. In all cases, New Zealand uses the same periods as those used internationally; the renaming only applies to subdivisions of these periods. Very few epochs and stages cross international period boundaries, and the exceptions are almost all within the Cenozoic Era. New Zealand updates will always be behind any significant international updates in the International Geological Time Scale. Although the New Zealand geologic time scale h ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
