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Little Yellow Bat
The little yellow bat (''Rhogeessa parvula'') is a species of vesper bat found only in Mexico. Description One of the smallest vesper bats, adult little yellow bats measure only in total length, with a forearm about long, and weigh just . There may be some cline (biology), clinal variation in body size, with the smallest individuals being found in the Nayarit region, and size increasing both to the north and south of this area. As the common name suggests, the fur is generally yellowish, with individual hairs being a fawn or chestnut brown for most of their length, and greyish brown at the base. The fur is silky in texture, and fades to a greyer shade on the animal's underside. The wing membranes are black and hairless, except for a small patch of fur on the membrane between the legs. The tail extends to the end of the uropatagium. The head is unusually small and narrow, with whiskers, small pointed ears, and tiny eyes. There is a wart above each eye, and another below the chi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Harrison Allen
Harrison Allen (1841–1897) was an American physician and anatomist, born in Philadelphia. He graduated from the medical department of the University of Pennsylvania in 1861, and in 1862 became a surgeon in the United States Army and served until the conclusion of the Civil War in 1865. In 1865 he was made professor of comparative anatomy and medical zoölogy at the University of Pennsylvania. He was transferred in 1878 to the chair of physiology, which he occupied until 1895. In 1867, he was elected as a member to the American Philosophical Society. He is buried at West Laurel Hill Cemetery, Lansdowne Section, Lot 205, in Bala Cynwyd Bala Cynwyd ( ) is a community in Lower Merion Township, Pennsylvania. It is located on the Philadelphia Main Line in Southeastern Pennsylvania, bordering the western edge of Philadelphia at U.S. Route 1 (City Avenue). It was originally two separa ..., Pennsylvania. Publications In addition to many papers contributed to medical journals, h ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mesquite
Mesquite is a common name for several plants in the genus ''Prosopis'', which contains over 40 species of small leguminous trees. They are native to dry areas in the Americas. They have extremely long roots to seek water from very far under ground. As a legume, mesquites are one of the few sources of fixed nitrogen in the desert habitat. These trees bloom from spring to summer. They often produce fruits known as "pods". ''Prosopis'' spp. are able to grow up to tall, depending on site and climate. They are deciduous and depending on location and rainfall have either deep or shallow roots. ''Prosopis'' is considered long-lived because of the low mortality rate after the dicotyledonous stage and juveniles are also able to survive in conditions with low light and drought. The Cahuilla indigenous people of western North America were known to eat the seeds of mesquite. History ''Prosopis'' spp. have been in North America since the Pliocene era and their wood has been dated to 3300 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bats Of Mexico
Bats are mammals of the order Chiroptera.''cheir'', "hand" and πτερόν''pteron'', "wing". With their forelimbs adapted as wings, they are the only mammals capable of true and sustained flight. Bats are more agile in flight than most birds, flying with their very long spread-out digits covered with a thin membrane or patagium. The smallest bat, and arguably the smallest extant mammal, is Kitti's hog-nosed bat, which is in length, across the wings and in mass. The largest bats are the flying foxes, with the giant golden-crowned flying fox, ''Acerodon jubatus'', reaching a weight of and having a wingspan of . The second largest order of mammals after rodents, bats comprise about 20% of all classified mammal species worldwide, with over 1,400 species. These were traditionally divided into two suborders: the largely fruit-eating megabats, and the echolocating microbats. But more recent evidence has supported dividing the order into Yinpterochiroptera and Yangochiropter ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Taxa Named By Harrison Allen
In biology, a taxon (back-formation from ''taxonomy''; plural taxa) is a group of one or more populations of an organism or organisms seen by taxonomists to form a unit. Although neither is required, a taxon is usually known by a particular name and given a particular ranking, especially if and when it is accepted or becomes established. It is very common, however, for taxonomists to remain at odds over what belongs to a taxon and the criteria used for inclusion. If a taxon is given a formal scientific name, its use is then governed by one of the nomenclature codes specifying which scientific name is correct for a particular grouping. Initial attempts at classifying and ordering organisms (plants and animals) were set forth in Carl Linnaeus's system in ''Systema Naturae'', 10th edition (1758), as well as an unpublished work by Bernard and Antoine Laurent de Jussieu. The idea of a unit-based system of biological classification was first made widely available in 1805 in the intro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mammals Described In 1866
Mammals () are a group of vertebrate animals constituting the class Mammalia (), characterized by the presence of mammary glands which in females produce milk for feeding (nursing) their young, a neocortex (a region of the brain), fur or hair, and three middle ear bones. These characteristics distinguish them from reptiles (including birds) from which they diverged in the Carboniferous, over 300 million years ago. Around 6,400 extant species of mammals have been described divided into 29 orders. The largest orders, in terms of number of species, are the rodents, bats, and Eulipotyphla (hedgehogs, moles, shrews, and others). The next three are the Primates (including humans, apes, monkeys, and others), the Artiodactyla ( cetaceans and even-toed ungulates), and the Carnivora (cats, dogs, seals, and others). In terms of cladistics, which reflects evolutionary history, mammals are the only living members of the Synapsida (synapsids); this clade, together with Sauropsi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rhogeessa
''Rhogeessa'' is a genus of bats within the vesper bats family, Vespertilionidae. Species *Yucatan yellow bat (''R. aeneus'') *Allen's yellow bat (''R. alleni'') * Bickham's little yellow bat (''Rhogeessa bickhami'') * Genoways's yellow bat (''R. genowaysi'') *Slender yellow bat (''R. gracilis'') *Husson's yellow bat (''R. hussoni'') * Thomas's yellow bat (''R. io'') * Menchu's little yellow bat (''R. menchuae'') * Tiny yellow bat (''R. minutilla'') *Least yellow bat (''R. mira'') * Little yellow bat (''R. parvula'') *Black-winged little yellow bat (''R. tumida'') * Ecuadorian little yellow bat (''R. velilla'') Taxonomy debate This genus is systematically complex and sometimes controversial. One reason that the genus is complex is because of the species' variable karyotypes:Baird, A. B., Hillis, D. M., Patton, J. C., & Bickham, J. W. (2008)Evolutionary history of the genus Rhogeessa (Chiroptera: Vespertilionidae) as revealed by mitochondrial DNA sequences Journal of Mammalogy, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lactation
Lactation describes the secretion of milk from the mammary glands and the period of time that a mother lactates to feed her young. The process naturally occurs with all sexually mature female mammals, although it may predate mammals. The process of feeding milk in all animals (including humans) is called ''nursing'', and in humans it is also called ''breastfeeding''. Newborn infants often produce some milk from their own breast tissue, known colloquially as witch's milk. In most species, lactation is a sign that the female has been pregnant at some point in her life, although it can happen without pregnancy. Nearly every species of mammal has nipples; except for monotremes, egg-laying mammals, which instead release milk through ducts in the abdomen. In only one species of mammal, the Dayak fruit bat from Southeast Asia, is milk production a normal male function. ''Galactopoiesis'' is the maintenance of milk production. This stage requires prolactin. Oxytocin is critical for t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chromosome
A chromosome is a long DNA molecule with part or all of the genetic material of an organism. In most chromosomes the very long thin DNA fibers are coated with packaging proteins; in eukaryotic cells the most important of these proteins are the histones. These proteins, aided by chaperone proteins, bind to and condense the DNA molecule to maintain its integrity. These chromosomes display a complex three-dimensional structure, which plays a significant role in transcriptional regulation. Chromosomes are normally visible under a light microscope only during the metaphase of cell division (where all chromosomes are aligned in the center of the cell in their condensed form). Before this happens, each chromosome is duplicated ( S phase), and both copies are joined by a centromere, resulting either in an X-shaped structure (pictured above), if the centromere is located equatorially, or a two-arm structure, if the centromere is located distally. The joined copies are now called si ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Diploid
Ploidy () is the number of complete sets of chromosomes in a cell, and hence the number of possible alleles for autosomal and pseudoautosomal genes. Sets of chromosomes refer to the number of maternal and paternal chromosome copies, respectively, in each homologous chromosome pair, which chromosomes naturally exist as. Somatic cells, tissues, and individual organisms can be described according to the number of sets of chromosomes present (the "ploidy level"): monoploid (1 set), diploid (2 sets), triploid (3 sets), tetraploid (4 sets), pentaploid (5 sets), hexaploid (6 sets), heptaploid or septaploid (7 sets), etc. The generic term polyploid is often used to describe cells with three or more chromosome sets. Virtually all sexually reproducing organisms are made up of somatic cells that are diploid or greater, but ploidy level may vary widely between different organisms, between different tissues within the same organism, and at different stages in an organism's life cycle. Half ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cactus
A cactus (, or less commonly, cactus) is a member of the plant family Cactaceae, a family comprising about 127 genera with some 1750 known species of the order Caryophyllales. The word ''cactus'' derives, through Latin, from the Ancient Greek word (''káktos''), a name originally used by Theophrastus for a spiny plant whose identity is now not certain. Cacti occur in a wide range of shapes and sizes. Although some species live in quite humid environments, most cacti live in habitats subject to at least some drought. Many live in extremely dry environments, even being found in the Atacama Desert, one of the driest places on Earth. Because of this, cacti show many adaptations to conserve water. For example, almost all cacti are succulents, meaning they have thickened, fleshy parts adapted to store water. Unlike many other succulents, the stem is the only part of most cacti where this vital process takes place. Most species of cacti have lost true leaves, retaining only spines, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Subtropical Vegetation
Vegetation classification is the process of classifying and mapping the vegetation over an area of the earth's surface. Vegetation classification is often performed by state based agencies as part of land use, resource and environmental management. Many different methods of vegetation classification have been used. In general, there has been a shift from structural classification used by forestry for the mapping of timber resources, to floristic community mapping for biodiversity management. Whereas older forestry-based schemes considered factors such as height, species and density of the woody canopy, floristic community mapping shifts the emphasis onto ecological factors such as climate, soil type and floristic associations. Classification mapping is usually now done using geographic information systems (GIS) software. Classification schemes Following, some important classification schemes. Köppen (1884) Although this scheme is in fact of a climate classification, it has a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vesper Bat
Vespertilionidae is a family of microbats, of the order Chiroptera, flying, insect-eating mammals variously described as the common, vesper, or simple nosed bats. The vespertilionid family is the most diverse and widely distributed of bat families, specialised in many forms to occupy a range of habitats and ecological circumstances, and it is frequently observed or the subject of research. The facial features of the species are often simple, as they mainly rely on vocally emitted echolocation. The tails of the species are enclosed by the lower flight membranes between the legs. Over 300 species are distributed all over the world, on every continent except Antarctica. It owes its name to the genus ''Vespertilio'', which takes its name from a word for bat, ', derived from the Latin term ' meaning 'evening'; they are termed "evening bats" and were once referred to as "evening birds". (The term "evening bat" also often refers more specifically to one of the species, '' Nycticeius humer ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
