1.
Taxonomy (biology)
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Taxonomy is the science of defining groups of biological organisms on the basis of shared characteristics and giving names to those groups. The exact definition of taxonomy varies from source to source, but the core of the remains, the conception, naming. There is some disagreement as to whether biological nomenclature is considered a part of taxonomy, the broadest meaning of taxonomy is used here. The word taxonomy was introduced in 1813 by Candolle, in his Théorie élémentaire de la botanique, the term alpha taxonomy is primarily used today to refer to the discipline of finding, describing, and naming taxa, particularly species. In earlier literature, the term had a different meaning, referring to morphological taxonomy, ideals can, it may be said, never be completely realized. They have, however, a value of acting as permanent stimulants. Some of us please ourselves by thinking we are now groping in a beta taxonomy, turrill thus explicitly excludes from alpha taxonomy various areas of study that he includes within taxonomy as a whole, such as ecology, physiology, genetics, and cytology. He further excludes phylogenetic reconstruction from alpha taxonomy, thus, Ernst Mayr in 1968 defined beta taxonomy as the classification of ranks higher than species. This activity is what the term denotes, it is also referred to as beta taxonomy. How species should be defined in a group of organisms gives rise to practical and theoretical problems that are referred to as the species problem. The scientific work of deciding how to define species has been called microtaxonomy, by extension, macrotaxonomy is the study of groups at higher taxonomic ranks, from subgenus and above only, than species. While some descriptions of taxonomic history attempt to date taxonomy to ancient civilizations, earlier works were primarily descriptive, and focused on plants that were useful in agriculture or medicine. There are a number of stages in scientific thinking. Early taxonomy was based on criteria, the so-called artificial systems. Later came systems based on a complete consideration of the characteristics of taxa, referred to as natural systems, such as those of de Jussieu, de Candolle and Bentham. The publication of Charles Darwins Origin of Species led to new ways of thinking about classification based on evolutionary relationships and this was the concept of phyletic systems, from 1883 onwards. This approach was typified by those of Eichler and Engler, the advent of molecular genetics and statistical methodology allowed the creation of the modern era of phylogenetic systems based on cladistics, rather than morphology alone. Taxonomy has been called the worlds oldest profession, and naming and classifying our surroundings has likely been taking place as long as mankind has been able to communicate
2.
Animal
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Animals are multicellular, eukaryotic organisms of the kingdom Animalia. The animal kingdom emerged as a clade within Apoikozoa as the group to the choanoflagellates. Animals are motile, meaning they can move spontaneously and independently at some point in their lives and their body plan eventually becomes fixed as they develop, although some undergo a process of metamorphosis later in their lives. All animals are heterotrophs, they must ingest other organisms or their products for sustenance, most known animal phyla appeared in the fossil record as marine species during the Cambrian explosion, about 542 million years ago. Animals can be divided broadly into vertebrates and invertebrates, vertebrates have a backbone or spine, and amount to less than five percent of all described animal species. They include fish, amphibians, reptiles, birds and mammals, the remaining animals are the invertebrates, which lack a backbone. These include molluscs, arthropods, annelids, nematodes, flatworms, cnidarians, ctenophores, the study of animals is called zoology. The word animal comes from the Latin animalis, meaning having breath, the biological definition of the word refers to all members of the kingdom Animalia, encompassing creatures as diverse as sponges, jellyfish, insects, and humans. Aristotle divided the world between animals and plants, and this was followed by Carl Linnaeus, in the first hierarchical classification. In Linnaeuss original scheme, the animals were one of three kingdoms, divided into the classes of Vermes, Insecta, Pisces, Amphibia, Aves, and Mammalia. Since then the last four have all been subsumed into a single phylum, in 1874, Ernst Haeckel divided the animal kingdom into two subkingdoms, Metazoa and Protozoa. The protozoa were later moved to the kingdom Protista, leaving only the metazoa, thus Metazoa is now considered a synonym of Animalia. Animals have several characteristics that set apart from other living things. Animals are eukaryotic and multicellular, which separates them from bacteria and they are heterotrophic, generally digesting food in an internal chamber, which separates them from plants and algae. They are also distinguished from plants, algae, and fungi by lacking cell walls. All animals are motile, if only at life stages. In most animals, embryos pass through a stage, which is a characteristic exclusive to animals. With a few exceptions, most notably the sponges and Placozoa and these include muscles, which are able to contract and control locomotion, and nerve tissues, which send and process signals
3.
Chordate
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Chordates are deuterostomes, as during the embryo development stage the anus forms before the mouth. They are also bilaterally symmetric coelomates, in the case of vertebrate chordates, the notochord is usually replaced by a vertebral column during development, and they may have body plans organized via segmentation. There are also additional extinct taxa, the Vertebrata are sometimes considered as a subgroup of the clade Craniata, consisting of chordates with a skull, the Craniata and Tunicata compose the clade Olfactores. Of the more than 65,000 living species of chordates, the worlds largest and fastest animals, the blue whale and peregrine falcon respectively, are chordates, as are humans. Fossil chordates are known from at least as early as the Cambrian explosion, Hemichordata, which includes the acorn worms, has been presented as a fourth chordate subphylum, but it now is usually treated as a separate phylum. The Hemichordata, along with the Echinodermata, form the Ambulacraria, the Chordata and Ambulacraria form the superphylum Deuterostomia, composed of the deuterostomes. Attempts to work out the relationships of the chordates have produced several hypotheses. All of the earliest chordate fossils have found in the Early Cambrian Chengjiang fauna. Because the fossil record of early chordates is poor, only molecular phylogenetics offers a prospect of dating their emergence. However, the use of molecular phylogenetics for dating evolutionary transitions is controversial and it has also proved difficult to produce a detailed classification within the living chordates. Attempts to produce family trees shows that many of the traditional classes are paraphyletic. While this has been known since the 19th century, an insistence on only monophyletic taxa has resulted in vertebrate classification being in a state of flux. Although the name Chordata is attributed to William Bateson, it was already in prevalent use by 1880, ernst Haeckel described a taxon comprising tunicates, cephalochordates, and vertebrates in 1866. Though he used the German vernacular form, it is allowed under the ICZN code because of its subsequent latinization, among the vertebrate sub-group of chordates the notochord develops into the spine, and in wholly aquatic species this helps the animal to swim by flexing its tail. In fish and other vertebrates, this develops into the spinal cord, the pharynx is the part of the throat immediately behind the mouth. In fish, the slits are modified to form gills, a muscular tail that extends backwards behind the anus. This is a groove in the wall of the pharynx. In filter-feeding species it produces mucus to gather food particles, which helps in transporting food to the esophagus and it also stores iodine, and may be a precursor of the vertebrate thyroid gland
4.
Mammal
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Mammals are any vertebrates within the class Mammalia, a clade of endothermic amniotes distinguished from reptiles by the possession of a neocortex, hair, three middle ear bones and mammary glands. All female mammals nurse their young with milk, secreted from the mammary glands, Mammals include the largest animals on the planet, the great whales. The basic body type is a quadruped, but some mammals are adapted for life at sea, in the air, in trees. The largest group of mammals, the placentals, have a placenta, Mammals range in size from the 30–40 mm bumblebee bat to the 30-meter blue whale. With the exception of the five species of monotreme, all modern mammals give birth to live young, most mammals, including the six most species-rich orders, belong to the placental group. The largest orders are the rodents, bats and Soricomorpha, the next three biggest orders, depending on the biological classification scheme used, are the Primates, the Cetartiodactyla, and the Carnivora. Living mammals are divided into the Yinotheria and Theriiformes There are around 5450 species of mammal, in some classifications, extant mammals are divided into two subclasses, the Prototheria, that is, the order Monotremata, and the Theria, or the infraclasses Metatheria and Eutheria. The marsupials constitute the group of the Metatheria, and include all living metatherians as well as many extinct ones. Much of the changes reflect the advances of cladistic analysis and molecular genetics, findings from molecular genetics, for example, have prompted adopting new groups, such as the Afrotheria, and abandoning traditional groups, such as the Insectivora. The mammals represent the only living Synapsida, which together with the Sauropsida form the Amniota clade, the early synapsid mammalian ancestors were sphenacodont pelycosaurs, a group that produced the non-mammalian Dimetrodon. At the end of the Carboniferous period, this group diverged from the line that led to todays reptiles. Some mammals are intelligent, with some possessing large brains, self-awareness, Mammals can communicate and vocalize in several different ways, including the production of ultrasound, scent-marking, alarm signals, singing, and echolocation. Mammals can organize themselves into fission-fusion societies, harems, and hierarchies, most mammals are polygynous, but some can be monogamous or polyandrous. They provided, and continue to provide, power for transport and agriculture, as well as commodities such as meat, dairy products, wool. Mammals are hunted or raced for sport, and are used as model organisms in science, Mammals have been depicted in art since Palaeolithic times, and appear in literature, film, mythology, and religion. Defaunation of mammals is primarily driven by anthropogenic factors, such as poaching and habitat destruction, Mammal classification has been through several iterations since Carl Linnaeus initially defined the class. No classification system is accepted, McKenna & Bell and Wilson & Reader provide useful recent compendiums. Though field work gradually made Simpsons classification outdated, it remains the closest thing to a classification of mammals
5.
Carnivora
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Carnivora is a diverse scrotiferan order that includes over 280 species of placental mammals. Its members are referred to as carnivorans, whereas the word carnivore can refer to any meat-eating organism.9 m in length. Some carnivorans, such as cats and pinnipeds, depend entirely on meat for their nutrition, carnivorans have teeth and claws adapted for catching and eating other animals. Many hunt in packs and are social animals, giving them an advantage over larger prey, carnivorans are split into two suborders, feliforms and caniforms. Carnivorans all share the same arrangement of teeth in which the last upper premolar, carnivorans have had this arrangement for over 60 million years with many adaptions, and these dental adaptions help identify carnivoran species and groupings of species. Carnivorans evolved in North America out of members of the family Miacidae about 42 million years ago and they soon split into cat-like and dog-like forms. Their molecular phylogeny shows the extant Carnivora are a monophyletic group, the last premolar of the upper jaw and first molar of the lower are termed the carnassials or sectorial teeth. These blade-like teeth occlude with an action for shearing and shredding meat. Carnassials are most highly developed in the Felidae and the least developed in the Ursidae, carnivorans have six incisors and two conical canines in each jaw. The only two exceptions to this are the sea otter, which has four incisors in the jaw, and the sloth bear. The number of molars and premolars is variable between species, but all teeth are deeply rooted and are diphyodont. Incisors are retained by carnivorans and the incisor is commonly large. Carnivorans have either four or five digits on each foot, with the first digit on the forepaws, also known as the dew claw, being vestigial in most species and absent in some. Most species are plain in coloration, lacking the flashy spotted or rosetted coats like many species of felids and viverrids have. This is because Canoidea tend to range in the temperate and subarctic biomes, most are terrestrial, although a few species, like procyonids, are arboreal. All families except the Canidae and a few species of Mustelidae are plantigrade, diet is varied and most tend to be omnivorous to some degree, and thus the carnassial teeth are less specialized. Canoidea have more premolars and molars in an elongated skull and this is because these species tend to range in tropical habitats, although a few species do inhabit temperate and subarctic habitats. Many are arboreal or semiarboreal, and the majority are digitigrade, diet tends to be more strictly carnivorous, especially in the family Felidae
6.
Hinrich Lichtenstein
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Martin Hinrich Carl Lichtenstein was a German physician, explorer, botanist and zoologist. Born in Hamburg, Lichtenstein was the son of Anton August Heinrich Lichtenstein and he studied medicine at Jena and Helmstedt. Between 1802 and 1806 he travelled in southern Africa, becoming the personal physician of the Governor of the Cape of Good Hope, in 1829, he was elected a foreign member of the Royal Swedish Academy of Sciences. He died after he had a stroke at sea travelling aboard a steamer from Korsør to Kiel, Lichtenstein was responsible for the creation of Berlins Zoological Gardens in 1841, when he persuaded King Frederick William IV of Prussia to donate the grounds of his pheasantry. He also published Johann Reinhold Forsters manuscripts for Descriptiones animalium in 1844, in the field of herpetology he described many new species of amphibians and reptiles. Among species named by Lichtenstein are included the Australian king parrot, crowned sandgrouse, in 1859 Italian herpetologist, Giorgio Jan, named the forest night adder in honor of Hinrich Lichtenstein, as did the Dutch zoologist Coenraad Jacob Temminck with the Lichtensteins sandgrouse. Mit einer Einführung von Wahrhold Drascher, ein Fragment aus dem Tagebuche des Hrn. Dr. Lichtenstein auf der Reise von Amsterdam nach dem Vorgebirge der guten Hofnung 1802, industrie-Comptoirs, Weimar 1806 Über die Beetjuanas. Als Nachtrag und Berichtigung zu Barrows Auszug aus Trüters Tagebuch einer Reise zu den Buschwanas, zur Geschichte der Sing-Akademie in Berlin. Nebst einer Nachricht über das Fest am funfzigsten Jahrestage Ihrer Stiftung und einem alphabetischen Verzeichniss aller Personen, ernst Rudorff, Briefe von Carl Maria von Weber an Hinrich Lichtenstein. Mit drei Porträts, drei Abbildungen und sechs Faksimiles, VIII Seiten,252 Seiten, mit Abb. Wilhelm Bölsche, Neue Welten. Die Eroberung der Erde in Darstellungen großer Naturforscher, thurston, H. T. Colby, F. M. eds
7.
Central America
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Central America is the southernmost, isthmian portion of the North American continent, which connects with South America on the southeast. Central America is bordered by Mexico to the north, Colombia to the southeast, the Caribbean Sea to the east, Central America consists of seven countries, Belize, Guatemala, El Salvador, Honduras, Nicaragua, Costa Rica and Panama. The combined population of Central America is between 41,739,000 and 42,688,190, Central America is a part of the Mesoamerican biodiversity hotspot, which extends from northern Guatemala through to central Panama. Due to the presence of several active faults and the Central America Volcanic Arc. Volcanic eruptions and earthquakes occur frequently, these disasters have resulted in the loss of many lives. In the Pre-Columbian era, Central America was inhabited by the peoples of Mesoamerica to the north and west. Soon after Christopher Columbuss voyages to the Americas, the Spanish began to colonize the Americas, the seven states finally became independent autonomous states, beginning with Nicaragua, Honduras, Costa Rica, and Guatemala, followed by El Salvador, then Panama, and finally Belize. Middle America is usually thought to comprise Mexico to the north of the 7 states of Central America as well as Colombia, usually the whole of the Caribbean to the north-east and sometimes the Guyanas are also included. According to one source, the term Central America was used as a synonym for Middle America as recently as 1962, in Brazil, Central America comprises all countries between Mexico and Colombia, including those in the Caribbean. Mexico, in whole or in part, is included by British people. For the people living in the 5 countries formerly part of the Federal Republic of Central America there is a distinction between the Spanish language terms América Central and Centroamérica, in the Pre-Columbian era, the northern areas of Central America were inhabited by the indigenous peoples of Mesoamerica. Most notable among these were the Mayans, who had built numerous cities throughout the region, and the Aztecs, following Christopher Columbuss voyages to the Americas, the Spanish sent many expeditions to the region, and they began their conquest of Maya territory in 1523. Soon after the conquest of the Aztec Empire, Spanish conquistador Pedro de Alvarado commenced the conquest of northern Central America for the Spanish Empire. Beginning with his arrival in Soconusco in 1523, Alvarados forces systematically conquered and subjugated most of the major Maya kingdoms, including the Kiche, Tzutujil, Pipil, and the Kaqchikel. By 1528, the conquest of Guatemala was nearly complete, with only the Petén Basin remaining outside the Spanish sphere of influence, the last independent Maya kingdoms – the Kowoj and the Itza people – were finally defeated in 1697, as part of the Spanish conquest of Petén. In 1538, Spain established the Real Audiencia of Panama, which had jurisdiction over all land from the Strait of Magellan to the Gulf of Fonseca. This entity was dissolved in 1543, and most of the territory within Central America then fell under the jurisdiction of the Audiencia Real de Guatemala. This area included the current territories of Costa Rica, El Salvador, Guatemala, Honduras, Nicaragua, and the Mexican state of Chiapas, the president of the Audiencia, which had its seat in Antigua Guatemala, was the governor of the entire area
8.
North America
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North America is a continent entirely within the Northern Hemisphere and almost all within the Western Hemisphere. It can also be considered a subcontinent of the Americas. It is bordered to the north by the Arctic Ocean, to the east by the Atlantic Ocean, to the west and south by the Pacific Ocean, and to the southeast by South America and the Caribbean Sea. North America covers an area of about 24,709,000 square kilometers, about 16. 5% of the land area. North America is the third largest continent by area, following Asia and Africa, and the fourth by population after Asia, Africa, and Europe. In 2013, its population was estimated at nearly 565 million people in 23 independent states, or about 7. 5% of the worlds population, North America was reached by its first human populations during the last glacial period, via crossing the Bering land bridge. The so-called Paleo-Indian period is taken to have lasted until about 10,000 years ago, the Classic stage spans roughly the 6th to 13th centuries. The Pre-Columbian era ended with the migrations and the arrival of European settlers during the Age of Discovery. Present-day cultural and ethnic patterns reflect different kind of interactions between European colonists, indigenous peoples, African slaves and their descendants, European influences are strongest in the northern parts of the continent while indigenous and African influences are relatively stronger in the south. Because of the history of colonialism, most North Americans speak English, Spanish or French, the Americas are usually accepted as having been named after the Italian explorer Amerigo Vespucci by the German cartographers Martin Waldseemüller and Matthias Ringmann. Vespucci, who explored South America between 1497 and 1502, was the first European to suggest that the Americas were not the East Indies, but a different landmass previously unknown by Europeans. In 1507, Waldseemüller produced a map, in which he placed the word America on the continent of South America. He explained the rationale for the name in the accompanying book Cosmographiae Introductio, for Waldseemüller, no one should object to the naming of the land after its discoverer. He used the Latinized version of Vespuccis name, but in its feminine form America, following the examples of Europa, Asia and Africa. Later, other mapmakers extended the name America to the continent, In 1538. Some argue that the convention is to use the surname for naming discoveries except in the case of royalty, a minutely explored belief that has been advanced is that America was named for a Spanish sailor bearing the ancient Visigothic name of Amairick. Another is that the name is rooted in a Native American language, the term North America maintains various definitions in accordance with location and context. In Canadian English, North America may be used to refer to the United States, alternatively, usage sometimes includes Greenland and Mexico, as well as offshore islands
9.
Skunk
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Skunks are mammals known for their ability to spray a liquid with a strong odor. Different species of skunk vary in appearance from black-and-white to brown or cream colored, 1630s, squunck, from a southern New England Algonquian language seganku, from Proto-Algonquian */šeka, kwa/, from */šek-/ to urinate + */-a, kw/ fox. Skunk has historic use as an insult, attested from 1841, skunk cabbage is attested from 1751, earlier skunkweed. In 1634, a skunk was described in the Jesuit Relations, The other is a low animal, I mention it here, not on account of its excellence, but to make of it a symbol of sin. I have seen three or four of them and it has black fur, quite beautiful and shining, and has upon its back two perfectly white stripes, which join near the neck and tail, making an oval which adds greatly to their grace. The tail is bushy and well furnished with hair, like the tail of a Fox and it is more white than black, and, at the first glance, you would say, especially when it walks, that it ought to be called Jupiters little dog. But it is so stinking, and casts so foul an odor, no sewer ever smelled so bad. I would not have believed it if I had not smelled it myself, I believe the sin smelled by Saint Catherine de Sienne must have had the same vile odor. Skunk species vary in size from about 15.6 to 37 in long and they have moderately elongated bodies with relatively short, well-muscled legs and long front claws for digging. Although the most common fur color is black and white, some skunks are brown or grey, all skunks are striped, even from birth. They may have a thick stripe across back and tail. Some also have stripes on their legs, skunks are omnivorous, eating both plant and animal material and changing their diets as the seasons change. They eat insects and larvae, earthworms, grubs, rodents, lizards, salamanders, frogs, snakes, birds, moles and they also commonly eat berries, roots, leaves, grasses, fungi and nuts. In settled areas, skunks also seek garbage left by humans, less often, skunks may be found acting as scavengers, eating bird and rodent carcasses left by cats or other animals. Pet owners, particularly those of cats, may experience a skunk finding its way into a garage or basement where pet food is kept, skunks commonly dig holes in lawns in search of grubs and worms. Skunks are one of the predators of the honeybee, relying on their thick fur to protect them from stings. The skunk scratches at the front of the beehive and eats the guard bees that come out to investigate, mother skunks are known to teach this behavior to their young. Skunks are crepuscular and solitary animals when not breeding, though in the parts of their range
10.
Museum of Osteology
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The Museum of Osteology is a private museum devoted to the study of bones and skeletons. This museum is located in Oklahoma City and displays over 350 skeletons from animal species from all over the world. With another 5000 skeletons as part of the collection, but not on display, the museum was established by Jay Villemarette, founder of the company Skulls Unlimited International, Inc. which is located next to the museum. Construction on the began in 2004 and opened to the public on October 1,2010. The museum focuses on the form and function of the system with numerous educational. The collections housed by the Museum of Osteology are the result of over 30 years of collecting by Jay Villemarette, currently the collections consist of approximately 5,000 specimens representing over 2,500 species of mammals, birds, reptiles, amphibians and fish. In 2015, the Museum of Osteology opened a location, Skeletons, Animals Unveiled, at the I-Drive 360 entertainment complex in Orlando. This location is slated as the largest skeleton museum in America with over 450 skeletons on display, official website Museum of Osteology on AdventureRoad. com Destination Information & Travel Planning
11.
Oklahoma
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Oklahoma is a state located in the South Central United States. Oklahoma is the 20th-most extensive and the 28th-most populous of the 50 United States, the states name is derived from the Choctaw words okla and humma, meaning red people. The name was settled upon statehood, Oklahoma Territory and Indian Territory were merged, on November 16,1907, Oklahoma became the 46th state to enter the union. Its residents are known as Oklahomans, or informally Okies, and its capital, a major producer of natural gas, oil, and agricultural products, Oklahoma relies on an economic base of aviation, energy, telecommunications, and biotechnology. In 2007, it had one of the economies in the United States, ranking among the top states in per capita income growth. Oklahoma City and Tulsa serve as Oklahomas primary economic anchors, with nearly two-thirds of Oklahomans living within their metropolitan statistical areas. With small mountain ranges, prairie, mesas, and eastern forests, most of Oklahoma lies in the Great Plains, Cross Timbers, interior Highlands—a region especially prone to severe weather. The name Oklahoma comes from the Choctaw phrase okla humma, literally meaning red people, equivalent to the English word Indian, okla humma was a phrase in the Choctaw language used to describe Native American people as a whole. Oklahoma later became the de facto name for Oklahoma Territory, and it was approved in 1890. Oklahoma is the 20th-largest state in the United States, covering an area of 69,898 square miles and it is one of six states on the Frontier Strip and lies partly in the Great Plains near the geographical center of the 48 contiguous states. It is bounded on the east by Arkansas and Missouri, on the north by Kansas, on the northwest by Colorado, on the far west by New Mexico, much of its border with Texas lies along the Southern Oklahoma Aulacogen, a failed continental rift. The geologic figure defines the placement of the Red River, the Oklahoma panhandles Western edge is out of alignment with its Texas border. The Oklahoma/New Mexico border is actually 2.1 to 2.2 miles east of the Texas line, the border between Texas and New Mexico was set first as a result of a survey by Spain in 1819. It was then set along the 103rd Meridian, in the 1890s, when Oklahoma was formally surveyed using more accurate surveying equipment and techniques, it was discovered the Texas line was not set along the 103rd Meridian. Surveying techniques were not as accurate in 1819, and the actual 103rd Meridian was approximately 2.2 miles to the east and it was much easier to leave the mistake than for Texas to cede land to New Mexico to correct the surveying error. The placement of the Oklahoma/New Mexico border represents the true 103rd Meridian, cimarron County in Oklahomas panhandle is the only county in the United States that touches four other states, New Mexico, Texas, Colorado and Kansas. Its highest and lowest points follow this trend, with its highest peak, Black Mesa, at 4,973 feet above sea level, situated near its far northwest corner in the Oklahoma Panhandle. The states lowest point is on the Little River near its far southeastern boundary near the town of Idabel, Oklahoma, which dips to 289 feet above sea level
12.
Canyon
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A canyon or gorge is a deep cleft between escarpments or cliffs resulting from the erosive activity of a river over geologic timescales. A canyon may also refer to a rift between two peaks, such as those in ranges including the Rocky Mountains, the Alps. Usually a river or stream and erosion carve out such splits between mountains, examples of mountain-type canyons are Provo Canyon in Utah or Yosemite National Park in Californias Sierra Nevada. Canyons within mountains, or gorges that have an opening on one side are called box canyons. Slot canyons are very narrow canyons, often with smooth walls, steep-sided valleys in the seabed of the continental slope underwater are referred to as submarine canyons. Unlike canyons on land, submarine canyons are thought to be formed by turbidity currents, the word canyon is Spanish in origin, with the same meaning. The word canyon is used in North America while the words gorge and ravine are used in Europe and Oceania, though gorge. In the United States, place names generally use canyon in the southwest and gorge in the northeast, in Canada, a gorge is usually narrow while a ravine is more open and often wooded. The military-derived word defile is occasionally used in the United Kingdom, most canyons were formed by a process of long-time erosion from a plateau or table-land level. The cliffs form because harder rock strata that are resistant to erosion, Canyons are much more common in arid than in wet areas because physical weathering has a more localized effect in arid zones. The wind and water from the combine to erode and cut away less resistant materials such as shales. The freezing and expansion of water also serves to help form canyons, water seeps into cracks between the rocks and freezes, pushing the rocks apart and eventually causing large chunks to break off the canyon walls, in a process known as frost wedging. Canyon walls are formed of resistant sandstones or granite. Sometimes large rivers run through canyons as the result of geological uplift. These are called entrenched rivers, because they are unable to alter their course. In the United States, the Colorado River in the Southwest, Canyons often form in areas of limestone rock. As limestone is soluble to an extent, cave systems form in the rock. When these collapse, a canyon is left, as in the Mendip Hills in Somerset and Yorkshire Dales in Yorkshire, England
Media related to Conepatus leuconotus at Wikimedia Commons
Data related to Conepatus leuconotus at Wikispecies
