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Alagteeg Formation
The Alagteeg Formation is a geological formation in Mongolia whose strata date back to the Late Cretaceous. Dinosaur remains are among the fossils that have been recovered from the formation.Weishampel et al., 2004, pp.593-600 It predominantly consists of alternating reddish brown mudstone and horizontally laminated sandstone, with ripple cross laminations and rhizoliths. It was first formally defined as a unit by Hasegawa et al in 2008 as a distinct unit from the overlying Djadochta Formation. The environment of deposition is suggested to be fluvial, originating in sandy braided river, floodplain and ephemeral lake depositional environments, as opposed to the desert depositional environment of the Djadochta Formation.Hasegawa et al., 2009 Vertebrate Paleofauna * '' Abdarainurus''Averianov & Lopatin, 2020 * ''Pinacosaurus'' * ''Plesiohadros'' * ''Protoceratops'' * Trionychidae indet. See also * List of dinosaur-bearing rock formations This list of dinosaur-bearing rock format ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Geological Formation
A geological formation, or simply formation, is a body of rock having a consistent set of physical characteristics ( lithology) that distinguishes it from adjacent bodies of rock, and which occupies a particular position in the layers of rock exposed in a geographical region (the stratigraphic column). It is the fundamental unit of lithostratigraphy, the study of strata or rock layers. A formation must be large enough that it can be mapped at the surface or traced in the subsurface. Formations are otherwise not defined by the thickness of their rock strata, which can vary widely. They are usually, but not universally, tabular in form. They may consist of a single lithology (rock type), or of alternating beds of two or more lithologies, or even a heterogeneous mixture of lithologies, so long as this distinguishes them from adjacent bodies of rock. The concept of a geologic formation goes back to the beginnings of modern scientific geology. The term was used by Abraham Gottlob Wer ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Trionychidae
The Trionychidae are a taxonomic family of a number of turtle genera, commonly known as softshell turtles. The family was erected by Leopold Fitzinger in 1826. Softshells include some of the world's largest freshwater turtles, though many can adapt to living in highly brackish areas. Members of this family occur in Africa, Asia, and North America, with extinct species known from Australia. Most species have traditionally been included in the genus ''Trionyx'', but the vast majority have since been moved to other genera. Among these are the North American ''Apalone'' softshells that were placed in ''Trionyx'' until 1987. Characteristics They are called "softshell" because their carapaces lack horny scutes (scales), though the spiny softshell, ''Apalone spinifera'', does have some scale-like projections, hence its name. The carapace is leathery and pliable, particularly at the sides. The central part of the carapace has a layer of solid bone beneath it, as in other turtles, but t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sandstone Formations
Sandstone is a Clastic rock#Sedimentary clastic rocks, clastic sedimentary rock composed mainly of grain size, sand-sized (0.0625 to 2 mm) silicate mineral, silicate grains. Sandstones comprise about 20–25% of all sedimentary rocks. Most sandstone is composed of quartz or feldspar (both silicates) because they are the most resistant minerals to weathering processes at the Earth's surface. Like uncemented sand, sandstone may be any color due to impurities within the minerals, but the most common colors are tan, brown, yellow, red, grey, pink, white, and black. Since sandstone beds often form highly visible cliffs and other topography, topographic features, certain colors of sandstone have been strongly identified with certain regions. Rock formations that are primarily composed of sandstone usually allow the percolation of water and other fluids and are porosity, porous enough to store large quantities, making them valuable aquifers and petroleum reservoirs. Quartz-b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Santonian Stage
The Santonian is an age in the geologic timescale or a chronostratigraphic stage. It is a subdivision of the Late Cretaceous Epoch or Upper Cretaceous Series. It spans the time between 86.3 ± 0.7 mya (million years ago) and 83.6 ± 0.7 mya. The Santonian is preceded by the Coniacian and is followed by the Campanian.Gradstein ''et al.'' (2004) Stratigraphic definition The Santonian Stage was established by French geologist Henri Coquand in 1857. It is named after the city of Saintes in the region of Saintonge, where the original type locality is located. The base of the Santonian Stage is defined by the appearance of the inoceramid bivalve ''Cladoceramus undulatoplicatus''. The GSSP (official reference profile) for the base of the Santonian Stage is located near Olazagutia, Spain; it was ratified by the Subcommission on Cretaceous Stratigraphy in 2012. The Santonian's top (the base of the Campanian Stage) is informally marked by the extinction of the crinoid '' Marsupites test ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Campanian Stage
The Campanian is the fifth of six age (geology), ages of the Late Cretaceous epoch (geology), Epoch on the geologic timescale of the International Commission on Stratigraphy (ICS). In chronostratigraphy, it is the fifth of six stage (stratigraphy), stages in the Upper Cretaceous series (stratigraphy), Series. Campanian spans the time from 83.6 (± 0.2) to 72.1 (± 0.2) million years ago. It is preceded by the Santonian and it is followed by the Maastrichtian. The Campanian was an age when a worldwide marine transgression, sea level rise covered many coastal areas. The geomorphology, morphology of some of these areas has been preserved: it is an unconformity beneath a cover of marine sedimentary rocks. Etymology The Campanian was introduced in scientific literature by Henri Coquand in 1857. It is named after the French village of Champagne, Charente-Maritime, Champagne in the department of Charente-Maritime. The original type locality (geology), type locality was a series of out ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cretaceous Mongolia
Cretaceous Mongolia is one of the strangest and best preserved of all Mesozoic ecosystems. The shifting sand of what was, even then, the Gobi Desert have ensured that fossils of the animals that lived there can be found in exactly the position in which they were buried, with most of the bones together. The most notable fossil is the very well preserved remains of a ''Velociraptor'', locked in combat with a ''Protoceratops'', a small ceratopsian. Dinosaurs in Mt. Altai Mt. Altai is unusual because the comparative lack of food means that most of the dinosaurs there remained quite small, most not much bigger than a present-day person. There were a few large dinosaurs, though. ''Tarbosaurus'' was the Mongol equivalent of ''Tyrannosaurus rex'' and was almost as large. The large herbivores grew into many strange shapes. ''Therizinosaurus'' was a bipedal herbivore about as tall as ''Tarbosaurus'' with a long neck, small head and characteristic long claws on the hands which it used for def ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Upper Cretaceous Series Of Asia
Upper may refer to: * Shoe upper or ''vamp'', the part of a shoe on the top of the foot * Stimulant, drugs which induce temporary improvements in either mental or physical function or both * ''Upper'', the original film title for the 2013 found footage film ''The Upper Footage ''The Upper Footage'' (also known as ''Upper'') is a 2013 found footage film written and directed by Justin Cole. First released on January 31, 2013 to a limited run of midnight theatrical screenings at Landmark’s Sunshine Cinema in New York Cit ...'' See also {{Disambiguation ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Geologic Formations Of Mongolia
Geology () is a branch of natural science concerned with Earth and other astronomical objects, the features or rocks of which it is composed, and the processes by which they change over time. Modern geology significantly overlaps all other Earth sciences, including hydrology, and so is treated as one major aspect of integrated Earth system science and planetary science. Geology describes the structure of the Earth on and beneath its surface, and the processes that have shaped that structure. It also provides tools to determine the relative and absolute ages of rocks found in a given location, and also to describe the histories of those rocks. By combining these tools, geologists are able to chronicle the geological history of the Earth as a whole, and also to demonstrate the age of the Earth. Geology provides the primary evidence for plate tectonics, the evolutionary history of life, and the Earth's past climates. Geologists broadly study the properties and processes of Ear ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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