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Black Shovel-nosed Salamander
The black shovel-nosed salamander (''Desmognathus melanius'') is a species of salamander in the family Plethodontidae. It is Endemism, endemic to the United States. It was described in 1956 but was later reclassified as synonymous with the shovelnose salamander (''D. marmoratus''). However, a 2009 Mitochondrial DNA, mtDNA study found sufficient genetic divergence to again classify as its own species. It is not recognized by other taxonomic authorities due to it being distinguished by mtDNA studies and problems with mtDNA introgression in the genus ''Desmognathus'', but it is still recognized by Darrel Frost pending publication of counter-evidence. It is found in the Nantahala River basin of western North Carolina and adjacent Tennessee. References Desmognathus Amphibians described in 1956 Endemic amphibians of the United States {{Plethodontidae-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Species
In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction. Other ways of defining species include their karyotype, DNA sequence, morphology, behaviour or ecological niche. In addition, paleontologists use the concept of the chronospecies since fossil reproduction cannot be examined. The most recent rigorous estimate for the total number of species of eukaryotes is between 8 and 8.7 million. However, only about 14% of these had been described by 2011. All species (except viruses) are given a two-part name, a "binomial". The first part of a binomial is the genus to which the species belongs. The second part is called the specific name or the specific epithet (in botanical nomenclature, also sometimes i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Salamander
Salamanders are a group of amphibians typically characterized by their lizard-like appearance, with slender bodies, blunt snouts, short limbs projecting at right angles to the body, and the presence of a tail in both larvae and adults. All ten extant salamander families are grouped together under the order Urodela. Salamander diversity is highest in eastern North America, especially in the Appalachian Mountains; most species are found in the Holarctic realm, with some species present in the Neotropical realm. Salamanders rarely have more than four toes on their front legs and five on their rear legs, but some species have fewer digits and others lack hind limbs. Their permeable skin usually makes them reliant on habitats in or near water or other cool, damp places. Some salamander species are fully aquatic throughout their lives, some take to the water intermittently, and others are entirely terrestrial as adults. This group of amphibians is capable of regenerating lost lim ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Plethodontidae
Plethodontidae, or lungless salamanders, are a family of salamanders. Most species are native to the Western Hemisphere, from British Columbia to Brazil, although a few species are found in Sardinia, Europe south of the Alps, and South Korea. In terms of number of species, they are by far the largest group of salamanders. Biology Adult lungless salamanders have four limbs, with four toes on the fore limbs, and usually with five on the hind limbs. Within many species, mating and reproduction occur solely on land. Accordingly, many species also lack an aquatic larval stage, a phenomenon known as direct development in which the offspring hatch as fully-formed, miniature adults. Direct development is correlated with changes in the developmental characteristics of plethodontids compared to other families of salamanders including increases in egg size and duration of embryonic development. Additionally, the evolutionary loss of the aquatic larval stage is related to a diminishing dep ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Endemism
Endemism is the state of a species being found in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also found elsewhere. For example, the Cape sugarbird is found exclusively in southwestern South Africa and is therefore said to be ''endemic'' to that particular part of the world. An endemic species can be also be referred to as an ''endemism'' or in scientific literature as an ''endemite''. For example '' Cytisus aeolicus'' is an endemite of the Italian flora. '' Adzharia renschi'' was once believed to be an endemite of the Caucasus, but it was later discovered to be a non-indigenous species from South America belonging to a different genus. The extreme opposite of an endemic species is one with a cosmopolitan distribution, having a global or widespread range. A rare alternative term for a species that is endemic is "precinctive", which applies to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
United States
The United States of America (U.S.A. or USA), commonly known as the United States (U.S. or US) or America, is a country primarily located in North America. It consists of 50 states, a federal district, five major unincorporated territories, nine Minor Outlying Islands, and 326 Indian reservations. The United States is also in free association with three Pacific Island sovereign states: the Federated States of Micronesia, the Marshall Islands, and the Republic of Palau. It is the world's third-largest country by both land and total area. It shares land borders with Canada to its north and with Mexico to its south and has maritime borders with the Bahamas, Cuba, Russia, and other nations. With a population of over 333 million, it is the most populous country in the Americas and the third most populous in the world. The national capital of the United States is Washington, D.C. and its most populous city and principal financial center is New York City. Paleo-Americ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Shovelnose Salamander
The shovelnose salamander (''Desmognathus marmoratus'') is a species of salamander in the family Plethodontidae. It is endemic to the United States. Taxonomy The golden shovel-nosed salamander (''D. aureatus'') and black shovel-nosed salamander (''D. melanius'') were both described in 1956, then synonymized with ''D. marmoratus'', but later revived as distinct species in 2009. However, their distinctiveness was quantified using mtDNA; due to heavy mtDNA introgression between ''Desmognathus'' species being a major problem with delineating their taxonomy, both species are not recognized by other taxonomic authorities. However, they are provisionally recognized by Darrel Frost unless proper counter-evidence is released. Description The shovelnose salamander is a robust species, broad with a relatively short tail. It receives its name from the shape of its snout which is more square ended than as seen in other salamanders in its genus. The colour is a dusky brown, grey or black w ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mitochondrial DNA
Mitochondrial DNA (mtDNA or mDNA) is the DNA located in mitochondria, cellular organelles within eukaryotic cells that convert chemical energy from food into a form that cells can use, such as adenosine triphosphate (ATP). Mitochondrial DNA is only a small portion of the DNA in a eukaryotic cell; most of the DNA can be found in the cell nucleus and, in plants and algae, also in plastids such as chloroplasts. Human mitochondrial DNA was the first significant part of the human genome to be sequenced. This sequencing revealed that the human mtDNA includes 16,569 base pairs and encodes 13 proteins. Since animal mtDNA evolves faster than nuclear genetic markers, it represents a mainstay of phylogenetics and evolutionary biology. It also permits an examination of the relatedness of populations, and so has become important in anthropology and biogeography. Origin Nuclear and mitochondrial DNA are thought to be of separate evolutionary origin, with the mtDNA being derived ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Desmognathus
''Desmognathus'' is a genus of lungless salamanders in the family Plethodontidae known as dusky salamanders. They range from Texas to the eastern United States and to south-eastern Canada. Characteristics Species of the genus ''Desmognathus'' have a unique jaw-opening mechanism where the lower jaw is stationary and the skull swings open. There are additional stalked condyles, an atlanto-mandibular ligament, along with other skeletal and musculature features that have evolved to accompany this type of jaw-opening mechanism. Additionally, they are known to exhibit maternal care by brooding over their eggs. Species This genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In the hierarchy of biological classification, genus com ... includes the following 30-31 species: References External links Tree of Life: Desmognathus* Further ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Darrel Frost
Darrel Richmond Frost (born 1951) is an American herpetologist and systematist. He was previously head curator of herpetology at the American Museum of Natural History, as well as president of both the Society for the Study of Amphibians and Reptiles (1998) and the American Society of Ichthyologists and Herpetologists (2006). Four taxa are named in his honor: the toad genus '' Frostius'' (which includes Frost's toad), the tree frog '' Dendropsophus frosti'', Darrel's chorus frog ''Microhyla darreli'', and Frost's arboreal alligator lizard '' Abronia frosti''. Life Frost became interested in animals after witnessing his father kill a rattlesnake at the age of four. He earned a B.S. in Biology from the University of Arizona in 1973, an M.S. in Zoology from Louisiana State University in 1978, and a Ph.D. in Ecology and Systematics from the University of Kansas in 1988. He became an adjunct professor at Columbia University in 2000. In 1990, Frost was appointed Assistant Curator of H ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nantahala River
The Nantahala River () , from the North Carolina Collection's website at the . Retrieved 2013-02-05. is a river in western in the , within the , and near the |
North Carolina
North Carolina () is a state in the Southeastern region of the United States. The state is the 28th largest and 9th-most populous of the United States. It is bordered by Virginia to the north, the Atlantic Ocean to the east, Georgia and South Carolina to the south, and Tennessee to the west. In the 2020 census, the state had a population of 10,439,388. Raleigh is the state's capital and Charlotte is its largest city. The Charlotte metropolitan area, with a population of 2,595,027 in 2020, is the most-populous metropolitan area in North Carolina, the 21st-most populous in the United States, and the largest banking center in the nation after New York City. The Raleigh-Durham-Cary combined statistical area is the second-largest metropolitan area in the state and 32nd-most populous in the United States, with a population of 2,043,867 in 2020, and is home to the largest research park in the United States, Research Triangle Park. The earliest evidence of human occupation i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tennessee
Tennessee ( , ), officially the State of Tennessee, is a landlocked state in the Southeastern region of the United States. Tennessee is the 36th-largest by area and the 15th-most populous of the 50 states. It is bordered by Kentucky to the north, Virginia to the northeast, North Carolina to the east, Georgia, Alabama, and Mississippi to the south, Arkansas to the southwest, and Missouri to the northwest. Tennessee is geographically, culturally, and legally divided into three Grand Divisions of East, Middle, and West Tennessee. Nashville is the state's capital and largest city, and anchors its largest metropolitan area. Other major cities include Memphis, Knoxville, Chattanooga, and Clarksville. Tennessee's population as of the 2020 United States census is approximately 6.9 million. Tennessee is rooted in the Watauga Association, a 1772 frontier pact generally regarded as the first constitutional government west of the Appalachian Mountains. Its name derives from "Tanas ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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