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Agaricocrinus Americanus (USA) 1
''Agaricocrinus americanus'', also known as the mushroom crinoid or American crinoid, is a species of extinct crinoid. Its fossils can be found in the U.S. states of Indiana, Tennessee and Kentucky. They date back to the Lower Mississippian, about 345 million years ago. Fossil beds One of the locations from which ''Agaricocrinus americanus'' is known is the Edwardsville Formation, in the vicinity of Crawfordsville, Montgomery County, Indiana, in the United States. In this fossil-rich bed have been found the fossils of sixty species of crinoid, distributed among more than forty genera. It is thought that the various species had different length stalks so that they could capture plankton drifting past at various heights above the substrate. The fossil beds were formed at a time when the seabed was much higher than it is today. It is believed that the crinoids were buried in sediment from nearby deltas during storms. The resulting siltstone deposits are soft enough for the fossil ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mississippian Age
The Mississippian ( , also known as Lower Carboniferous or Early Carboniferous) is a subperiod in the geologic timescale or a subsystem of the geologic record. It is the earlier of two subperiods of the Carboniferous period lasting from roughly 358.9 to 323.2 million years ago. As with most other geochronologic units, the rock beds that define the Mississippian are well identified, but the exact start and end dates are uncertain by a few million years. The Mississippian is so named because rocks with this age are exposed in the Mississippi Valley. The Mississippian was a period of marine transgression in the Northern Hemisphere: the sea level was so high that only the Fennoscandian Shield and the Laurentian Shield were dry land. The cratons were surrounded by extensive delta systems and lagoons, and carbonate sedimentation on the surrounding continental platforms, covered by shallow seas. In North America, where the interval consists primarily of marine limestones, it is treate ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Plankton
Plankton are the diverse collection of organisms found in Hydrosphere, water (or atmosphere, air) that are unable to propel themselves against a Ocean current, current (or wind). The individual organisms constituting plankton are called plankters. In the ocean, they provide a crucial source of food to many small and large aquatic organisms, such as bivalves, fish and whales. Marine plankton include bacteria, archaea, algae, protozoa and drifting or floating animals that inhabit the saltwater of oceans and the brackish waters of estuaries. Freshwater plankton are similar to marine plankton, but are found in the freshwaters of lakes and rivers. Plankton are usually thought of as inhabiting water, but there are also airborne versions, the aeroplankton, that live part of their lives drifting in the atmosphere. These include plant spores, pollen and wind-scattered seeds, as well as microorganisms swept into the air from terrestrial dust storms and oceanic plankton swept into the air ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Calyx (anatomy)
Calyx is a term used in animal anatomy for some cuplike areas or structures. Etymology Latin, from ''calyx'' (from Ancient Greek ''κάλυξ, ''case of a bud, husk"). Cnidarians The spicules containing the basal portion of the upper tentacular part of the polyp of some soft corals (also called ''calice''). Entoprocta A body part of the Entoprocta from which tentacles arise and the mouth and anus are located. Echinoderms The body disk that is covered with a leathery tegumen containing calcareous plates (in crinoids and ophiuroids the main part of the body where the viscera are located). Humans Either a minor calyx in the kidney, a conglomeration of two or three minor calyces to form a major calyx, or the Calyx of Held, a particularly large synapse in the mammalian auditory central nervous system, named by H. Held in his 1893 article ''Die centrale Gehörleitung'', due to its flower-petal-like shape. Satzler, K., L. F. Sohl, et al. (2002). "Three-dimensional reconstruction ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Holdfast (biology)
A holdfast is a root-like structure that anchors aquatic sessile organisms, such as seaweed, other sessile algae, stalked crinoids, benthic cnidarians, and sponges, to the substrate. Holdfasts vary in shape and form depending on both the species and the substrate type. The holdfasts of organisms that live in muddy substrates often have complex tangles of root-like growths. These projections are called haptera and similar structures of the same name are found on lichens. The holdfasts of organisms that live in sandy substrates are bulb-like and very flexible, such as those of sea pens, thus permitting the organism to pull the entire body into the substrate when the holdfast is contracted. The holdfasts of organisms that live on smooth surfaces (such as the surface of a boulder) have flattened bases which adhere to the surface. The organism derives no nutrition from this intimate contact with the substrate, as the process of liberating nutrients from the substrate requires ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Extant Taxon
Neontology is a part of biology that, in contrast to paleontology, deals with living (or, more generally, '' recent'') organisms. It is the study of extant taxa (singular: extant taxon): taxa (such as species, genera and families) with members still alive, as opposed to (all) being extinct. For example: * The moose (''Alces alces'') is an extant species, and the dodo (''Raphus cucullatus'') is an extinct species. * In the group of molluscs known as the cephalopods, there were approximately 600 extant species and 7,500 extinct species. A taxon can be classified as extinct if it is broadly agreed or certified that no members of the group are still alive. Conversely, an extinct taxon can be reclassified as extant if there are new discoveries of living species ("Lazarus species"), or if previously-known extant species are reclassified as members of the taxon. Most biologists, zoologists, and botanists are in practice neontologists, and the term neontologist is used large ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Agaricocrinus Crassus
''Agaricocrinus'' is a genus of extinct crinoids, belonging to the family Coelocrinidae. These stationary upper-level epifaunal suspension feeders lived in the Carboniferous period and in the Osagean age of United States, from 353.8 to 345.0 Ma. Selected species *''Agaricocrinus americanus'' Roemer *''Agaricocrinus splendens'' Miller and Gurley Description Like extant Extant is the opposite of the word extinct. It may refer to: * Extant hereditary titles * Extant literature, surviving literature, such as ''Beowulf'', the oldest extant manuscript written in English * Extant taxon, a taxon which is not extinct, ... crinoids, ''Agaricocrinus'' species was anchored to a hard surface by a holdfast out of which grew an articulated stalk. On top of this was a calyx with a number of feather-like arms. Each arm bore short branches known as pinnules and from these cirri were extended which sifted plankton from the water flowing past. References Prehistoric crinoid genera Ca ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Synonym (taxonomy)
The Botanical and Zoological Codes of nomenclature treat the concept of synonymy differently. * In botanical nomenclature, a synonym is a scientific name that applies to a taxon that (now) goes by a different scientific name. For example, Linnaeus was the first to give a scientific name (under the currently used system of scientific nomenclature) to the Norway spruce, which he called ''Pinus abies''. This name is no longer in use, so it is now a synonym of the current scientific name, ''Picea abies''. * In zoology, moving a species from one genus to another results in a different binomen, but the name is considered an alternative combination rather than a synonym. The concept of synonymy in zoology is reserved for two names at the same rank that refers to a taxon at that rank - for example, the name ''Papilio prorsa'' Linnaeus, 1758 is a junior synonym of ''Papilio levana'' Linnaeus, 1758, being names for different seasonal forms of the species now referred to as ''Araschnia le ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fort Payne Formation
The Fort Payne Formation, or Fort Payne Chert, is a geologic formation found in the southeastern United States, southeastern region of the United States. It is a Mississippian (geologic period), Mississippian Period cherty limestone, that overlies the Chattanooga Shale (or locally the Maury Formation), and underlies the St. Louis Limestone (lower Tuscumbia Limestone in Alabama). To the north, it grades into the siltstone Borden Formation. It preserves fossils dating back to the Carboniferous Period (geology), period. Eugene Allen Smith named the Fort Payne Formation for outcrops at Fort Payne, Alabama. See also * * * Mississippian (geologic period) * List of fossiliferous stratigraphic units in Kentucky References Geologic formations of Alabama Geologic formations of Tennessee Mississippian United States Carboniferous Alabama Carboniferous Kentucky Carboniferous geology of Tennessee Viséan Limestone formations of the United States Chert Carboniferous southern pal ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Davidson County, Tennessee
Davidson County is a county in the U.S. state of Tennessee. It is located in the heart of Middle Tennessee. As of the 2020 census, the population was 715,884, making it the second most populous county in Tennessee. Its county seat is Nashville, the state capital and largest city. Since 1963, the city of Nashville and Davidson County have had a consolidated government called the "Metropolitan Government of Nashville and Davidson County", commonly referred to as "Metro Nashville" or "Metro". Davidson County has the largest population in the 13-county Nashville-Davidson–Murfreesboro–Franklin Metropolitan Statistical Area, the state's most populous metropolitan area. Nashville has always been the region's center of commerce, industry, transportation, and culture, but it did not become the capital of Tennessee until 1827 and did not gain permanent capital status until 1843. History Davidson County is the oldest county in the 41-county region of Middle Tennessee. It dates to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Whites Creek, Tennessee
Whites Creek is an unincorporated community located near Nashville in the northern part of Davidson County, Tennessee. The community and nearby creek which travels north to south along US 431 were named after an early settler named White who was killed by hostile American Indians prior to the settlement of Fort Nashboro in 1778. The Whites Creek area has its own US Post Office, with the ZIP Code 37189. The historic Whites Creek District was established in 1780 and has some of the best preserved examples of the architectural and historical significance of this era in Middle Tennessee. It is now a part of Metro Nashville, Tennessee, Nashville. History The legendary James-Younger Gang, James Gang outlaws visited Whites Creek and rested there in the 1800s. Gang member Bill Ryan was arrested on March 25, 1881 in Whites Creek, prompting gang leaders Frank James, Frank and Jesse James to leave the area. Whites Creek Comprehensive High School is the community's only high school. The sc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Agaricocrinus Americanus (USA) 1
''Agaricocrinus americanus'', also known as the mushroom crinoid or American crinoid, is a species of extinct crinoid. Its fossils can be found in the U.S. states of Indiana, Tennessee and Kentucky. They date back to the Lower Mississippian, about 345 million years ago. Fossil beds One of the locations from which ''Agaricocrinus americanus'' is known is the Edwardsville Formation, in the vicinity of Crawfordsville, Montgomery County, Indiana, in the United States. In this fossil-rich bed have been found the fossils of sixty species of crinoid, distributed among more than forty genera. It is thought that the various species had different length stalks so that they could capture plankton drifting past at various heights above the substrate. The fossil beds were formed at a time when the seabed was much higher than it is today. It is believed that the crinoids were buried in sediment from nearby deltas during storms. The resulting siltstone deposits are soft enough for the fossil ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Siltstone
Siltstone, also known as aleurolite, is a clastic sedimentary rock that is composed mostly of silt. It is a form of mudrock with a low clay mineral content, which can be distinguished from shale by its lack of fissility.Blatt ''et al.'' 1980, pp.381-382 Although its permeability and porosity is relatively low, siltstone is sometimes a tight gas reservoir rock, an unconventional reservoir for natural gas that requires hydraulic fracturing for economic gas production. Siltstone was prized in ancient Egypt for manufacturing statuary and cosmetic palettes. The siltstone quarried at Wadi Hammamat was a hard, fine-grained siltstone that resisted flaking and was almost ideal for such uses. Description There is not complete agreement on the definition of siltstone. One definition is that siltstone is mudrock ( clastic sedimentary rock containing at least 50% clay and silt) in which at least 2/3 of the clay and silt fraction is composed of silt-sized particles. Silt is defined a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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