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Del Norte Salamander
The Del Norte salamander (''Plethodon elongatus'') is a species of salamander in the family Plethodontidae endemic to the United States in southwestern Oregon and northwestern California. Description ''Plethodon elongatus'' is a medium-sized, slender salamander. Adults are from snout to vent, and in total length. Limbs are relatively short; toes are short and slightly webbed. Dorsal coloration is dark brown or black. A reddish or reddish-brown straight-edged mid-dorsal stripe may extend from the head to the tip of the tail; the stripe may be less pronounced in older animals. Life history ''P. elongatus'' is a fully terrestrial salamander. Clutch size is three to 11 eggs (mean eight). No free-living larval stage exists, and juveniles hatch completely metamorphosed, measuring about in snout–vent length. Habitat and conservation The species occurs in areas of moist talus and rocky substrates in redwood or Douglas fir forests. It is typically encountered among moss-covered roc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
John Van Denburgh
John Van Denburgh (August 23, 1872 – October 24, 1924) was an American herpetologist from California (who also used the name Van Denburgh in publications, hence this name is used below). Biography Van Denburgh was born in San Francisco and enrolled at Stanford University in 1891. As of 1895, he organized the herpetology department of the California Academy of Sciences. In 1897, he received a Ph.D. from Stanford University and earned a M.D. from Johns Hopkins in 1902. Subsequently, he practiced medicine in San Francisco, while again serving as curator of the herpetological collections of the California Academy of Sciences. After the San Francisco earthquake of 1906 he was instrumental in rebuilding the lost herpetology collections through new expeditions and also acquisitions of other collections. In 1922, he published the two-volume ''The Reptiles of Western North America''. He died in 1924 while on vacation in Honolulu Honolulu (; ) is the capital and largest city of t ... [...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] |
Endemic
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] |
Oregon
Oregon () is a U.S. state, state in the Pacific Northwest region of the Western United States. The Columbia River delineates much of Oregon's northern boundary with Washington (state), Washington, while the Snake River delineates much of its eastern boundary with Idaho. The 42nd parallel north, 42° north parallel delineates the southern boundary with California and Nevada. Oregon has been home to many Indigenous peoples of the Americas, indigenous nations for thousands of years. The first European traders, explorers, and settlers began exploring what is now Oregon's Pacific coast in the early-mid 16th century. As early as 1564, the Spanish expeditions to the Pacific Northwest, Spanish began sending vessels northeast from the Philippines, riding the Kuroshio Current in a sweeping circular route across the northern part of the Pacific. In 1592, Juan de Fuca undertook detailed mapping and studies of ocean currents in the Pacific Northwest, including the Oregon coast as well as ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
California
California is a U.S. state, state in the Western United States, located along the West Coast of the United States, Pacific Coast. With nearly 39.2million residents across a total area of approximately , it is the List of states and territories of the United States by population, most populous U.S. state and the List of U.S. states and territories by area, 3rd largest by area. It is also the most populated Administrative division, subnational entity in North America and the 34th most populous in the world. The Greater Los Angeles area and the San Francisco Bay Area are the nation's second and fifth most populous Statistical area (United States), urban regions respectively, with the former having more than 18.7million residents and the latter having over 9.6million. Sacramento, California, Sacramento is the state's capital, while Los Angeles is the List of largest California cities by population, most populous city in the state and the List of United States cities by population, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Snout–vent Length
Snout–vent length (SVL) is a morphometric measurement taken in herpetology from the tip of the snout to the most posterior opening of the cloacal slit (vent)."direct line distance from tip of snout to posterior margin of vent" It is the most common measurement taken in herpetology, being used for all amphibians, lepidosaurs, and crocodilians (for turtles, carapace length (CL) and plastral length (PL) are used instead). The SVL differs depending on whether the animal is struggling or relaxed (if alive), or various other factors if it is a preserved specimen. For fossils, an osteological correlate Osteological correlates are marks on the bones of animals that are made from the causal interactions of the soft-tissue Soft tissue is all the tissue in the body that is not hardened by the processes of ossification or calcification such as bo ... such as precaudal length must be used. When combined with weight and body condition, SVL can help deduce age and sex. Advantages Bec ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sequoia Sempervirens
''Sequoia sempervirens'' ()''Sunset Western Garden Book,'' 1995:606–607 is the sole living species of the genus '' Sequoia'' in the cypress family Cupressaceae (formerly treated in Taxodiaceae). Common names include coast redwood, coastal redwood, and California redwood. It is an evergreen, long-lived, monoecious tree living 1,200–2,200 years or more. This species includes the tallest living trees on Earth, reaching up to in height (without the roots) and up to in diameter at breast height. These trees are also among the oldest living things on Earth. Before commercial logging and clearing began by the 1850s, this massive tree occurred naturally in an estimated along much of coastal California (excluding southern California where rainfall is not sufficient) and the southwestern corner of coastal Oregon within the United States. The name sequoia sometimes refers to the subfamily Sequoioideae, which includes ''S. sempervirens'' along with ''Sequoiadendron'' (gi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Douglas Fir
The Douglas fir (''Pseudotsuga menziesii'') is an evergreen conifer species in the pine family, Pinaceae. It is native to western North America and is also known as Douglas-fir, Douglas spruce, Oregon pine, and Columbian pine. There are three varieties: coast Douglas-fir (''P. menziesii'' var. ''menziesii''), Rocky Mountain Douglas-fir (''P. menziesii'' var. ''glauca'') and Mexican Douglas-fir (''P. menziesii'' var. ''lindleyana''). Despite its common names, it is not a true fir (genus ''Abies''), spruce (genus '' Picea''), or pine (genus ''Pinus''). It is also not a hemlock; the genus name ''Pseudotsuga'' means "false hemlock". Description Douglas-firs are medium-size to extremely large evergreen trees, tall (although only ''Pseudotsuga menziesii var. menziesii'', common name coast Douglas-firs, reach heights near 100 m) and commonly reach in diameter, although trees with diameters of almost exist. The largest coast Douglas-firs regularly live over 500 years, with the old ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Habitat Loss
Habitat destruction (also termed habitat loss and habitat reduction) is the process by which a natural habitat becomes incapable of supporting its native species. The organisms that previously inhabited the site are displaced or dead, thereby reducing biodiversity and species abundance. Habitat destruction is the leading cause of biodiversity loss. Fragmentation and loss of habitat have become one of the most important topics of research in ecology as they are major threats to the survival of endangered species. Activities such as harvesting natural resources, industrial production and urbanization are human contributions to habitat destruction. Pressure from agriculture is the principal human cause. Some others include mining, logging, trawling, and urban sprawl. Habitat destruction is currently considered the primary cause of species extinction worldwide. Environmental factors can contribute to habitat destruction more indirectly. Geological processes, climate change, introdu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Plethodon
''Plethodon'' is a genus of salamanders in the family Plethodontidae. They are also known as woodland salamanders or, more rarely, slimy salamanders. All members of the genus are endemic to North America (Canada and USA). They have no aquatic larval stage. In some species, such as ''Plethodon cinereus'', the red-backed salamander, eggs are laid underneath a stone or log. Young hatch in the adult form. Members of ''Plethodon'' primarily eat small invertebrates. The earliest known fossils of this genus are from the Hemphillian of Tennessee in the United States. Species There are 56 species in the genus ''Plethodon''. Listed in alphabetical order of specific name: ''Nota bene'': A binomial authority In taxonomy, binomial nomenclature ("two-term naming system"), also called nomenclature ("two-name naming system") or binary nomenclature, is a formal system of naming species of living things by giving each a name composed of two parts, bot ... in parentheses indicates that th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Amphibians Of The United States
Amphibians are four-limbed and ectothermic vertebrates of the class Amphibia. All living amphibians belong to the group Lissamphibia. They inhabit a wide variety of habitats, with most species living within terrestrial, fossorial, arboreal or freshwater aquatic ecosystems. Thus amphibians typically start out as larvae living in water, but some species have developed behavioural adaptations to bypass this. The young generally undergo metamorphosis from larva with gills to an adult air-breathing form with lungs. Amphibians use their skin as a secondary respiratory surface and some small terrestrial salamanders and frogs lack lungs and rely entirely on their skin. They are superficially similar to reptiles like lizards but, along with mammals and birds, reptiles are amniotes and do not require water bodies in which to breed. With their complex reproductive needs and permeable skins, amphibians are often ecological indicators; in recent decades there has been a dramatic decline ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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