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Eliurus Carletoni
The Ankarana Special Reserve tufted-tailed rat (''Eliurus carletoni'') (synonymous with ''Eliurus'' sp. SAJ-2009a) is a species of rodent in the family Nesomyidae. It was first described in 2009. It is endemic to Madagascar, in the Ankarana Special Reserve. Distribution and morphology ''E. carletoni'' is a relatively new species restricted to Northern Madagascar. The species was named in honor of Dr. Michael Carleton of the National Museum of Natural History for his substantial influence in the study of rodent systematics and of rodents native to the island of Madagascar. Currently, ''E. carletoni'' is endemic to the Réserve Spéciale (RS) d’Ankarana. Madagascar is widely known for its unique biomes and biota. The genus ''Eliurus'' is part of the order Rodentia and the family Nesomyidae. ''E. carletoni'' can be characterized by the following: Overall, the texture of body hair is soft and fine. Cover hairs of the dorsum are bi-colored (proximal two-thirds is dark brown, and th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rodent
Rodents (from Latin , 'to gnaw') are mammals of the order Rodentia (), which are characterized by a single pair of continuously growing incisors in each of the upper and lower jaws. About 40% of all mammal species are rodents. They are native to all major land masses except for New Zealand, Antarctica, and several oceanic islands, though they have subsequently been introduced to most of these land masses by human activity. Rodents are extremely diverse in their ecology and lifestyles and can be found in almost every terrestrial habitat, including human-made environments. Species can be arboreal, fossorial (burrowing), saltatorial/richochetal (leaping on their hind legs), or semiaquatic. However, all rodents share several morphological features, including having only a single upper and lower pair of ever-growing incisors. Well-known rodents include mice, rats, squirrels, prairie dogs, porcupines, beavers, guinea pigs, and hamsters. Rabbits, hares, and pikas, whose i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nesomyidae
The Nesomyidae are a family of African rodents in the large and complex superfamily Muroidea. It includes several subfamilies, all of which are native to either continental Africa or to Madagascar. Included in this family are Malagasy rodents, climbing mice, African rock mice, swamp mice, pouched rats, and the white-tailed rat. Characteristics Nesomyids are small- to medium-sized rodents, with the largest being the size of a rat. Physically, they may resemble mice, rats, voles, or hamsters, depending on the species and subfamily. Their diets vary from fairly strict herbivory to nearly pure insectivory. Their habits are similarly variable, with some species climbing trees, and others burrowing in the ground. They give birth to up to four young after a gestation period around six weeks. Classification Many of these animals were once thought to be related to other groups of muroid rodents, but this African-based clade has been proposed and confirmed on the basis of genetic ... [...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] |
Madagascar
Madagascar (; mg, Madagasikara, ), officially the Republic of Madagascar ( mg, Repoblikan'i Madagasikara, links=no, ; french: République de Madagascar), is an island country in the Indian Ocean, approximately off the coast of East Africa across the Mozambique Channel. At Madagascar is the world's List of island countries, second-largest island country, after Indonesia. The nation is home to around 30 million inhabitants and consists of the island of Geography of Madagascar, Madagascar (the List of islands by area, fourth-largest island in the world), along with numerous smaller peripheral islands. Following the prehistoric breakup of the supercontinent Gondwana, Madagascar split from the Indian subcontinent around 90 million years ago, allowing native plants and animals to evolve in relative isolation. Consequently, Madagascar is a biodiversity hotspot; over 90% of wildlife of Madagascar, its wildlife is endemic. Human settlement of Madagascar occurred during or befo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ankarana Reserve
Ankarana Special Reserve in northern Madagascar was created in 1956. It is a small, partially vegetated plateau composed of 150-million-year-old middle Jurassic limestone. With an average annual rainfall of about , the underlying rocks have been eroded to produce caves and feed subterranean rivers—a karst topography. The rugged relief and the dense vegetation have helped protect the region from human intrusion. The southern entrance of the park is in Mahamasina on the Route nationale 6 (Madagascar), Route nationale 6 some 108 km south-west of Antsiranana and north-east of Ambilobe. Geology The plateau slopes gently to the east, but on the west it ends abruptly in the "Wall of Ankarana", a sheer cliff that extends north to south, and rises up to . To the south, the limestone mass breaks up into separate spires known as ''tower karst''. In the center of the plateau, seismic activity and eons of rainfall have eroded the limestone, forming deep gorges and ribbons of flowsto ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
National Museum Of Natural History
The National Museum of Natural History is a natural history museum administered by the Smithsonian Institution, located on the National Mall in Washington, D.C., United States. It has free admission and is open 364 days a year. In 2021, with 7.1 million visitors, it was the eighteenth most visited museum in the world and the second most visited natural history museum in the world after the Natural History Museum in London."The World's most popular museums", CNN.com, 22 June 2017. Opened in 1910, the museum on the National Mall was one of the first Smithsonian buildings constructed exclusively to hold the national collections and research facilities. The main building has an overall area of with of exhibition and public space and houses over 1,000 employees. The museum's collections contain over 145 million specimens of plants, animals, fossils, minerals, rocks, meteorites, human remains, and human cultural artifacts, the largest natural history collection in the world. It i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Loky-Manambato
Loky-Manambato is a protected area in northern Madagascar. The protected area covers 2484.09 km2,UNEP-WCMC (2022)Protected Area Profile for Loky Manambatofrom the World Database on Protected Areas. Accessed 18 September 2022. and includes a block of dry deciduous forests, mangroves, and a large lake. It is located in northern Sava Region, bounded on the north by the Loky River, on the south by the Manambato River, and on the east by the Indian Ocean. Flora and fauna Loky-Manambato is in the dry deciduous forests of northern Madagascar, near the transition to the moist evergreen forests of eastern Madagascar and the montane forests of Madagascar's central highlands. Plant communities in the protected area include montane moist evergreen forest, moist semideciduous rainforest, dry deciduous forest, riparian forest, rupicolous vegetation, littoral forest, swamp forest, humid grassland, marsh, lake, mangrove, secondary grassland, secondary thicket, and secondary forest. 8 species ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Limestone
Limestone ( calcium carbonate ) is a type of carbonate sedimentary rock which is the main source of the material lime. It is composed mostly of the minerals calcite and aragonite, which are different crystal forms of . Limestone forms when these minerals precipitate out of water containing dissolved calcium. This can take place through both biological and nonbiological processes, though biological processes, such as the accumulation of corals and shells in the sea, have likely been more important for the last 540 million years. Limestone often contains fossils which provide scientists with information on ancient environments and on the evolution of life. About 20% to 25% of sedimentary rock is carbonate rock, and most of this is limestone. The remaining carbonate rock is mostly dolomite, a closely related rock, which contains a high percentage of the mineral dolomite, . ''Magnesian limestone'' is an obsolete and poorly-defined term used variously for dolomite, for limes ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Topography
Topography is the study of the forms and features of land surfaces. The topography of an area may refer to the land forms and features themselves, or a description or depiction in maps. Topography is a field of geoscience and planetary science and is concerned with local detail in general, including not only relief, but also natural, artificial, and cultural features such as roads, land boundaries, and buildings. In the United States, topography often means specifically ''relief'', even though the USGS topographic maps record not just elevation contours, but also roads, populated places, structures, land boundaries, and so on. Topography in a narrow sense involves the recording of relief or terrain, the three-dimensional quality of the surface, and the identification of specific landforms; this is also known as geomorphometry. In modern usage, this involves generation of elevation data in digital form (DEM). It is often considered to include the graphic representation of t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Epididymis
The epididymis (; plural: epididymides or ) is a tube that connects a testicle to a vas deferens in the male reproductive system. It is a single, narrow, tightly-coiled tube in adult humans, in length. It serves as an interconnection between the multiple efferent ducts at the rear of a testicle (proximally), and the vas deferens (distally). Anatomy The epididymis is situated posterior and somewhat lateral to the testis. The epididymis is invested completely by the tunica vaginalis (which is continuous with the tunica vaginalis covering the testis). The epididymis can be divided into three main regions: * The head ( la, caput). The head of the epididymis receives spermatozoa via the efferent ducts of the mediastinium of the testis at the superior pole of the testis. The head is characterized histologically by a thick epithelium with long stereocilia (described below) and a little smooth muscle. It is involved in absorbing fluid to make the sperm more concentrated. The concentrat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mammary Gland
A mammary gland is an exocrine gland in humans and other mammals that produces milk to feed young offspring. Mammals get their name from the Latin word ''mamma'', "breast". The mammary glands are arranged in organs such as the breasts in primates (for example, humans and chimpanzees), the udder in ruminants (for example, cows, goats, sheep, and deer), and the dugs of other animals (for example, dogs and cats). Lactorrhea, the occasional production of milk by the glands, can occur in any mammal, but in most mammals, lactation, the production of enough milk for nursing, occurs only in phenotypic females who have gestated in recent months or years. It is directed by hormonal guidance from sex steroids. In a few mammalian species, male lactation can occur. With humans, male lactation can occur only under specific circumstances. Mammals are divided into 3 groups: prototherians, metatherians, and eutherians. In the case of prototherians, both males and females have functional mamm ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Population Bottleneck
A population bottleneck or genetic bottleneck is a sharp reduction in the size of a population due to environmental events such as famines, earthquakes, floods, fires, disease, and droughts; or human activities such as specicide, widespread violence or intentional culling, and human population planning. Such events can reduce the variation in the gene pool of a population; thereafter, a smaller population, with a smaller genetic diversity, remains to pass on genes to future generations of offspring through sexual reproduction. Genetic diversity remains lower, increasing only when gene flow from another population occurs or very slowly increasing with time as random mutations occur. This results in a reduction in the robustness of the population and in its ability to adapt to and survive natural selection, selecting environmental changes, such as Climate change (general concept), climate change or a shift in available resources. Alternatively, if survivors of the bottleneck are the i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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