|
Railroad Valley Toad
The Railroad Valley toad (''Anaxyrus nevadensis'') is a species of toad in the family Bufonidae. It is endemic to Nye County in the state of Nevada in the United States. Taxonomy It was formerly considered an isolated population of the common western toad (''A. boreas'') until morphological and phylogenetic analyses found it to be a separate species, and described it as such (alongside the Hot Creek toad, ''A. monfontanus'') in 2020. The Dixie Valley toad (''A. williamsi'') was described a few years earlier for the same reasons. Phylogenetic evidence indicates that ''A. nevadensis'' and ''A. monfontanus'' are more closely related to ''A. boreas'' from modern-day Colorado and Utah than they are to any other members of the complex; hydrological analysis indicates that this may be because the White River and Colorado River likely had a historical connection, allowing western toads from those regions to colonize the southern Great Basin The Great Basin is the largest ... [...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] |
Colorado River
The Colorado River ( es, Río Colorado) is one of the principal rivers (along with the Rio Grande) in the Southwestern United States and northern Mexico. The river drains an expansive, arid drainage basin, watershed that encompasses parts of seven U.S. states and two Mexican states. The name Colorado derives from the Spanish language for "colored reddish" due to its heavy silt load. Starting in the central Rocky Mountains of Colorado, it flows generally southwest across the Colorado Plateau and through the Grand Canyon before reaching Lake Mead on the Arizona–Nevada border, where it turns south toward the Mexico–United States border, international border. After entering Mexico, the Colorado approaches the mostly dry Colorado River Delta at the tip of the Gulf of California between Baja California and Sonora. Known for its dramatic canyons, whitewater rapids, and eleven National parks of the United States, U.S. National Parks, the Colorado River and its tributaries are a v ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Endemic Fauna Of Nevada
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 s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Anaxyrus
''Anaxyrus'' is a genus of true toads in the family Bufonidae. The genus is endemic to North and Central America. Some authors consider ''Anaxyrus'' to be a subgenus within ''Bufo ''Bufo'' is a genus of true toads in the amphibian family Bufonidae. As traditionally defined, it was a wastebasket genus containing a large number of toads from much of the world, but following taxonomic reviews most of these have been moved to ...''. Species References External links * * * Further reading * Tschudi JJ (1845). "''Reptilium conspectus quae in Republica Peruana reperiuntur et pleraque observata vel collecta sunt in itinere''". ''Archiv für Naturgeschichte'' 11 (1): 150–170. (''Anaxyrus'', new genus, p. 170). (in Latin) {{Taxonbar, from=Q2279985 Taxa named by Johann Jakob von Tschudi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Petroleum Reservoir
A petroleum reservoir or oil and gas reservoir is a subsurface accumulation of hydrocarbons contained in porous or fractured rock formations. Such reservoirs form when kerogen (ancient plant matter) is created in surrounding rock by the presence of high heat and pressure in the Earth's crust. Petroleum reservoirs are broadly classified as ''conventional'' and '' unconventional'' reservoirs. In conventional reservoirs, the naturally occurring hydrocarbons, such as crude oil or natural gas, are trapped by overlying rock formations with lower permeability, while in unconventional reservoirs, the rocks have high porosity and low permeability, which keeps the hydrocarbons trapped in place, therefore not requiring a cap rock. Reservoirs are found using hydrocarbon exploration methods. Oil field An oil field is an area of accumulation of liquid oil underground in multiple (potentially linked) reservoirs, trapped as it rises by impermeable rock formations. In industrial terms, an o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Parotoid Gland
The parotoid gland (alternatively, paratoid gland) is an external skin gland on the back, neck, and shoulder of toads and some frogs and salamanders. It can secrete a number of milky alkaloid substances (depending on the species) known collectively as bufotoxins, which act as neurotoxins to deter predation. These cutaneous glands are called parotoid as they are somewhat similarly positioned to mammalian parotid gland, although the latter have a different function, excreting saliva within the mouth rather than externally excreted defensive chemicals. A study of the parotoid glands of the Colorado River toad in 1976 found that the parotoid glands were "composed of numerous lobules", each of which is a separate unit with a lumen surrounded by a double cell layer. The cell layers have interlocking microvilli. The study found that the outer cell layer resembled smooth muscle cells, with some organelles hypothesised to "function in some aspects of venom synthesis, active cellular trans ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Species Complex
In biology, a species complex is a group of closely related organisms that are so similar in appearance and other features that the boundaries between them are often unclear. The taxa in the complex may be able to hybridize readily with each other, further blurring any distinctions. Terms that are sometimes used synonymously but have more precise meanings are cryptic species for two or more species hidden under one species name, sibling species for two (or more) species that are each other's closest relative, and species flock for a group of closely related species that live in the same habitat. As informal taxonomic ranks, species group, species aggregate, macrospecies, and superspecies are also in use. Two or more taxa that were once considered conspecific (of the same species) may later be subdivided into infraspecific taxa (taxa within a species, such as bacterial strains or plant varieties), that is complex but it is not a species complex. A species complex is in most cas ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sagebrush Steppe
Sagebrush steppe is a type of shrub-steppe, a plant community characterized by the presence of shrubs, and usually dominated by sagebrush, any of several species in the genus ''Artemisia''.Sagebrush steppe. National Park Service. This ecosystem is found in the in the United States.Sagebrush Steppe Conservation Project /ID National Lab. Wildlife Conservation Society. The most common sagebrush species in the sagebrush steppe in mo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Railroad Valley (Nevada)
Railroad Valley is one of the Central Nevada Desert Basins in the Tonopah Basin and is about long north-south and up to wide, with some southern areas running southwest to northeast. Description The southern end of the valley begins near Gray Top Mountain (elevation ) and stretches north all the way to Mount Hamilton (elevation ). To the east are the Quinn Canyon, Grant, and White Pine Ranges, while to the west are the Pancake and Reveille Ranges. Most of the valley lies in Nye County, but it crosses into White Pine County at its northern end.Nevada Atlas & Gazetteer, 2001, pgs. 47, 55, and 61 The valley includes numerous springs including Kate Springs and Blue Eagle Springranches such as the Blue Eagle Ranch, and 2 Tonopah Basin, Tonopah Playas. The valley has 4 separate Wildlife Management Areas ("Railroad Valley WMA"), and valley communities include Currant, Crows Nest, Green Springs, Lockes, and Nyala. Most of Nevada's oil production (totalling about 553,000 barrel ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Great Basin
The Great Basin is the largest area of contiguous endorheic basin, endorheic watersheds, those with no outlets, in North America. It spans nearly all of Nevada, much of Utah, and portions of California, Idaho, Oregon, Wyoming, and Baja California. It is noted for both its arid climate and the basin and range topography that varies from the North American low point at Badwater Basin in Death Valley to the highest point of the contiguous United States, less than away at the summit of Mount Whitney. The region spans several physical geography, physiographic divisions, biomes, ecoregions, and deserts. Definition The term "Great Basin" is applied to hydrography, hydrographic, ecology, biological, floristic province, floristic, physiographic, topography, topographic, and Ethnography, ethnographic geographic areas. The name was originally coined by John C. Frémont, who, based on information gleaned from Joseph R. Walker as well as his own travels, recognized the hydrographic nature o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
White River (Nevada)
The White River is a small and discontinuous river located in southeastern Nevada notable for several endemic species of fish. The river was named for F. A. White, a 19th-century explorer. Course The White River begins at the Great Basin Divide in the White Pine Range near Ely, where it is fed by snowmelt and springs from Currant Mountain. It passes by the towns of Preston and Lund, flowing south through the White River Valley more or less continuously for about . Along the way it receives water from various springs on the slopes of the Grant Range to the west and the Egan Range to the east. It provides the water for a string of reservoirs along its course in the Sunnyside area, the largest being Adams-McGill Reservoir. State Route 318 runs mostly parallel to the river. The river channel is dry for some distance, then the water flows again in the Pahranagat Valley for about , from the vicinity of Hiko and Crystal Springs, passing close by Alamo, feeding Upper Pahrana ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
.jpg "Click for more on -> Endemic Fauna Of Nevada")
