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Hsanda Gol Formation
The Hsanda Gol Formation is a geological formation located in the Tsagan Nor Basin of central Mongolia that dates to the Rupelian age of the Oligocene epoch. It formed in continental desert-like conditions and is notable for its fossil mammals, first excavated by Roy Chapman Andrews and the American Museum of Natural History in the 1920s. Hsanda Gol is included in the Hsandagolian Asian Land Mammal Age, to which it gives its name. Geology The 2600 feet thick Hsanda Gol formation is covered in various places by Miocene-age variegated clays, sands, and gravels. It rests on top of the Early Cretaceous Hühteeg Svita formation. The lower portions of the formation are composed of yellow conglomerate, with the higher areas being dominated by red clays, silts and sands, as well as lava and basalt flows. Hsanda Gol was traditionally assigned to the Middle Oligocene, but after the reassignation of the preceding Ergilian age to the Late Eocene it has now been rendered early Oligocene. I ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Indricotherium Transouralicum
''Paraceratherium'' is an extinct genus of hornless rhinoceros. It is one of the largest terrestrial mammals that has existed and lived from the early to late Oligocene epoch (34–23 million years ago). The first fossils were discovered in what is now Pakistan, and remains have been found across Eurasia between China and the Balkans. It is classified as a member of the family Paraceratheriidae. ''Paraceratherium'' means "near the hornless beast", in reference to ''Aceratherium'', the genus in which the type species ''P. bugtiense'' was originally placed. The exact size of ''Paraceratherium'' is unknown because of the incompleteness of the fossils. The shoulder height was about , and the length about . Its weight is estimated to have been about . The long neck supported a skull that was about long. It had large, tusk-like incisors and a nasal incision that suggests it had a prehensile upper lip or proboscis (trunk). The legs were long and pillar-like. The lifestyle of ' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hühteeg Svita
The Khuren Dukh Formation, also known as the Hühteeg Svita, ( mn, Хөхтээг формаци, ) is a geological formation in Mongolia whose strata date back to the middle to late Albian.Nichols et al., 2006 Dinosaur remains are among the fossils that have been recovered from the formation.Weishampel et al., 2004, pp.563-570 Vertebrate paleofauna Dinosaurs Choristoderes See also * List of dinosaur-bearing rock formations This list of dinosaur-bearing rock formations is a list of geologic formations in which dinosaur fossils have been documented. Containing body fossils * List of stratigraphic units with dinosaur body fossils ** List of stratigraphic units with ... References Bibliography * * * * {{DEFAULTSORT:Huhteeg Svita Geologic formations of Mongolia Lower Cretaceous Series of Asia Cretaceous Mongolia Albian Stage Sandstone formations Mudstone formations Lacustrine deposits Paleontology in Mongolia Formations ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chalicothere
Chalicotheres (from Greek '' chalix'', "gravel" and '' therion'', "beast") are an extinct clade of herbivorous, odd-toed ungulate (perissodactyl) mammals that lived in North America, Eurasia, and Africa from the Middle Eocene until the Early Pleistocene, existing from 48.6 to 1.806 mya. They are one of the five major radiations of perissodactyls, with three groups living (horses, plus the extinct paleotheres; rhinoceroses; tapirs), and two extinct (brontotheres and chalicotheres). Description Unlike modern perissodactyls, chalicotheres had clawed feet. They had longer forelimbs and shorter hind limbs, lower incisors that cropped food against a toothless pad in the upper jaw, low-crowned molar teeth, and were browsers on trees and shrubs throughout their history. They evolved in two different directions, which became separate subfamilies, the Schizotheriinae and the Chalicotheriinae. Schizotherine chalicotheres such as ''Moropus'' lived in a variety of forest, woodland, and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Entelodont
Entelodontidae, the entelodonts, are an extinct family of pig-like artiodactyls (even-toed ungulates) which inhabited the Northern Hemisphere (Asia, Europe, and North America) from the late Eocene to the Middle Miocene epochs, about 38-19 million years ago. Their large heads, low snouts, narrow gait, and proposed omnivorous diet inspires comparisons to suids (true pigs) and tayassuids (peccaries), and historically they have been considered closely related to these families purely on a morphological basis. However, studies which combine morphological and molecular (genetic) data on artiodactyls instead suggest that entelodonts are cetancodontamorphs, more closely related to hippos and cetaceans than to pigs or other ungulates. Description Entelodonts could get quite large, and in many cases are the largest mammals in their respective ecosystems. The largest entelodont known from a complete skeleton was ''Daeodon'', a North American entelodont which could reach an estimated we ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rhinocerotidae
A rhinoceros (; ; ), commonly abbreviated to rhino, is a member of any of the five extant species (or numerous extinct species) of odd-toed ungulates in the family Rhinocerotidae. (It can also refer to a member of any of the extinct species of the superfamily Rhinocerotoidea.) Two of the extant species are native to Africa, and three to South and Southeast Asia. Rhinoceroses are some of the largest remaining megafauna: all weigh at least one tonne in adulthood. They have a herbivorous diet, small brains (400–600 g) for mammals of their size, one or two horns, and a thick (1.5–5 cm), protective skin formed from layers of collagen positioned in a lattice structure. They generally eat leafy material, although their ability to ferment food in their hindgut allows them to subsist on more fibrous plant matter when necessary. Unlike other perissodactyls, the two African species of rhinoceros lack teeth at the front of their mouths; they rely instead on their lips t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Amynodont
Amynodontidae ("defensive tooth") is a family of extinct perissodactyls related to true rhinoceroses. They are commonly portrayed as semiaquatic hippo-like rhinos but this description only fits members of the Metamynodontini; other groups of amynodonts like the cadurcodontines had more typical ungulate proportions and convergently evolved a tapir-like proboscis. The Greek name of the family describes their tusks, derived from enlarged canine teeth. Odd-toed ungulates are herbivores, so these tusks would have been used either to deter or defend against predators (as suggested by the name) or perhaps in fights among males.http://www.rhinoresourcecenter.com/pdf_files/141/1415340780.pdf Their fossils have been found in North America, and Eurasia ranging in age from the Middle Eocene to the Early Oligocene, with a single genus (''Cadurcotherium'') surviving into the Late Oligocene in South Asia (Pakistan). The genus ''Metamynodon'' may have survived into the early Miocene. Taxono ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Brontothere
Brontotheriidae is a family of extinct mammals belonging to the order Perissodactyla, the order that includes horses, rhinoceroses, and tapirs. Superficially, they looked rather like rhinos, although they were actually more closely related to horses; Equidae and Brontotheriidae make up the suborder Hippomorpha. They lived around 56–34 million years ago, until the very close of the Eocene. Characteristics and evolution Brontotheres retain four toes on their front feet and three toes on their hind feet. Their teeth are adapted to shearing (cutting) relatively nonabrasive vegetation. Their molars have a characteristic W-shaped ectoloph (outer shearing blade). The evolutionary history of this group is well known due to an excellent fossil record in North America. The earliest brontotheres, such as ''Eotitanops'', were rather small, no more than a meter in height, and hornless. Brontotheres evolved massive bodies, although some small species such as ''Nanotitanops'' did pers ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Indricothere
Paraceratheriidae is an extinct family of long-limbed, hornless rhinocerotoids, commonly known as paraceratheres or indricotheres, that originated in the Eocene epoch and lived until the early Miocene. The first paraceratheres were only about the size of large dogs, growing progressively larger in the late Eocene and Oligocene. They were most common in the rainforest floodplain region which is now Kazakhstan, India, and southwest China, and lived further inland throughout northern and central Asia as well. The paraceratheres reached the peak of their evolution from the middle Oligocene to the early Miocene, where they became very large, herbivorous mammals. Most genera were about the size of modern draft horses and the extinct giant horse '' Equus giganteus'', with some growing significantly larger. The largest genus was ''Paraceratherium'', which was more than twice as heavy as a bull African elephant, and was one of the largest land mammals that ever lived. However, they rem ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hyaenodont
Hyaenodonta ("hyena teeth") is an extinct order of hypercarnivorous placental pan-carnivoran mammals from mirorder Ferae. Hyaenodonts were important mammalian predators that arose during the early Paleocene in Europe and persisted well into the late Miocene. Characteristics Hyaenodonts are characterized by long skulls, slender jaws, slim bodies and a plantigrade stance. They generally ranged in size from 30 to 140 cm at the shoulder. While '' Simbakubwa kutokaafrika'' may have been up to (surpassing the modern polar bear in size) and ''Hyaenodon gigas'' (the largest species from genus ''Hyaenodon'') was as much as 1.4 m high at the shoulder, 3.0 m long and weighed about 330 kg, most of hyaenodonts were in the 5–15 kg range, equivalent to a mid-sized dog. The anatomy of their skulls show that they had a particularly acute sense of smell, while their teeth were adapted for shearing, rather than crushing. Because of their size range, it is probable that diffe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ephemeral
Ephemerality (from the Greek word , meaning 'lasting only one day') is the concept of things being transitory, existing only briefly. Academically, the term ephemeral constitutionally describes a diverse assortment of things and experiences, from digital media to types of streams. "There is no single definition of ephemerality". With respect to unique performances, for example, it has been noted that " hemerality is a quality caused by the ebb and flow of the crowd's concentration on the performance and a reflection of the nostalgic character of specific performances". Because different people may value the passage of time differently, ephemerality may be a relative, perceptual concept: "In brief, what is short-lived may not be the object itself, but the attention we afford it".Ronald Beiner, ''Political Philosophy: What It Is and Why It Matters'' (2014), p. 10. Ephemerality and nature Geographical features An ephemeral stream is that which only exists following precipitation. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lava Flow
Lava is molten or partially molten rock (magma) that has been expelled from the interior of a terrestrial planet (such as Earth) or a moon onto its surface. Lava may be erupted at a volcano or through a fracture in the crust, on land or underwater, usually at temperatures from . The volcanic rock resulting from subsequent cooling is also often called ''lava''. A lava flow is an outpouring of lava during an effusive eruption. (An explosive eruption, by contrast, produces a mixture of volcanic ash and other fragments called tephra, not lava flows.) The viscosity of most lava is about that of ketchup, roughly 10,000 to 100,000 times that of water. Even so, lava can flow great distances before cooling causes it to solidify, because lava exposed to air quickly develops a solid crust that insulates the remaining liquid lava, helping to keep it hot and inviscid enough to continue flowing. The word ''lava'' comes from Italian and is probably derived from the Latin word ''labes'', ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Paleomagnetism
Paleomagnetism (or palaeomagnetismsee ), is the study of magnetic fields recorded in rocks, sediment, or archeological materials. Geophysicists who specialize in paleomagnetism are called ''paleomagnetists.'' Certain magnetic minerals in rocks can record the direction and intensity of Earth's magnetic field at the time they formed. This record provides information on the past behavior of the geomagnetic field and the past location of tectonic plates. The record of geomagnetic reversals preserved in volcanic and sedimentary rock sequences (magnetostratigraphy) provides a time-scale that is used as a geochronologic tool. Evidence from paleomagnetism led to the revival of the continental drift hypothesis and its transformation into the modern theory of plate tectonics. Apparent polar wander paths provided the first clear geophysical evidence for continental drift, while marine magnetic anomaly, magnetic anomalies did the same for seafloor spreading. Paleomagnetic data continues t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
