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Corneous
Corneous is a biological and medical term meaning horny, in other words made out of a substance similar to that of horns and hooves in some mammals. The word is generally used to describe natural or pathological anatomical structures made out of a hard layer of protein. In mammals this protein would usually be keratin. The word corneous is also often used to describe the operculum of a snail, a gastropod mollusc. Not all gastropods have opercula, but in the great majority of those that do have one, the operculum is corneous. (However in several genera within a few families including the marine Naticidae and the terrestrial Pomatiidae, the operculum is primarily calcareous, in other words mostly made of calcium carbonate Calcium carbonate is a chemical compound with the chemical formula . It is a common substance found in Rock (geology), rocks as the minerals calcite and aragonite, most notably in chalk and limestone, eggshells, gastropod shells, shellfish skel ....) Co ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Keratin
Keratin () is one of a family of structural fibrous proteins also known as ''scleroproteins''. It is the key structural material making up Scale (anatomy), scales, hair, Nail (anatomy), nails, feathers, horn (anatomy), horns, claws, Hoof, hooves, and the outer layer of skin in vertebrates. Keratin also protects epithelial cells from damage or stress. Keratin is extremely insoluble in water and organic solvents. Keratin monomers assemble into bundles to form intermediate filaments, which are tough and form strong mineralization (biology), unmineralized epidermal appendages found in reptiles, birds, amphibians, and mammals. Excessive keratinization participate in fortification of certain tissues such as in horns of cattle and rhinos, and armadillos' osteoderm. The only other biology, biological matter known to approximate the toughness of keratinized tissue is chitin. Keratin comes in two types: the primitive, softer forms found in all vertebrates and the harder, derived forms fou ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Conchiolin
Conchiolins (sometimes referred to as conchins) are complex proteins which are secreted by a mollusc's outer epithelium (the mantle). These proteins are part of a matrix of organic macromolecules, mainly proteins and polysaccharides, that assembled together form the microenvironment where crystals nucleate and grow. This organic matrix also holds and binds to the crystals of aragonite which give such shells their stiffness. The ions necessary to form calcium carbonate are also secreted by the mantle, but it is the tailored environment created by the organic matrix which causes aragonite (rather than calcite) crystals to nucleate, in much the same way that collagen nucleates hydroxyapatite crystals. Conchiolin serves as a relatively flexible, crack-deflecting matrix for the mineral aggregate particles; its strength and the strong bonding of perlucin can in some cases (such as in the formation of nacre) give the finished material an impressive level of toughness. As well ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Horn
Horn may refer to: Common uses * Horn (acoustic), a tapered sound guide ** Horn antenna ** Horn loudspeaker ** Vehicle horn ** Train horn *Horn (anatomy), a pointed, bony projection on the head of various animals * Horn (instrument), a family of musical instruments ** French horn, often simply called a horn Arts and entertainment * ''Horn'' (album), by Apink, 2022 * ''Horn'', a 2011 album by Pharaoh Overlord * "The Horn", a song by Super Furry Animals from the 2005 album '' Love Kraft'' * "The Horn", a comedy track from the 1978 album '' Derek and Clive Ad Nauseam'' * ''Horn'' (video game), 2012 * The Horn (film), a 2020 Sri Lankan Sinhala sci-fi horror film Places * Horn of Africa * Horn District, Austria ** Horn, Austria * Horn (am Bodensee), Baden-Württemberg, Germany * Horn, Hamburg, Germany * Horn Island (Mississippi), United States * Horn, Nebraska, United States * Horn, Netherlands * Horn Island, Queensland, Australia * Horn, a ferry docking point on Rand ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mollusc
Mollusca is a phylum of protostome, protostomic invertebrate animals, whose members are known as molluscs or mollusks (). Around 76,000 extant taxon, extant species of molluscs are recognized, making it the second-largest animal phylum after Arthropoda. The number of additional fossil species is estimated between 60,000 and 100,000, and the proportion of undescribed species is very high. Many taxa remain poorly studied. Molluscs are the largest marine biology, marine phylum, comprising about 23% of all the named marine organisms. They are highly diverse, not just in size and anatomical structure, but also in behaviour and habitat, as numerous groups are freshwater mollusc, freshwater and even terrestrial molluscs, terrestrial species. The phylum is typically divided into 7 or 8 taxonomy (biology), taxonomic class (biology), classes, of which two are entirely extinct. Cephalopod molluscs, such as squid, cuttlefish, and octopuses, are among the most neurobiology, neurologi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Animal Anatomy
Anatomy () is the branch of Morphology (biology), morphology concerned with the study of the internal structure of organisms and their parts. Anatomy is a branch of natural science that deals with the structural organization of living things. It is an old science, having its beginnings in prehistoric times. Anatomy is inherently tied to developmental biology, embryology, comparative anatomy, evolutionary biology, and phylogeny, as these are the processes by which anatomy is generated, both over immediate and long-term timescales. Anatomy and physiology, which study the structure and function (biology), function of organisms and their parts respectively, make a natural pair of related disciplines, and are often studied together. Human anatomy is one of the essential basic sciences that are applied in medicine, and is often studied alongside physiology. Anatomy is a complex and dynamic field that is constantly evolving as discoveries are made. In recent years, there has been a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dictionary
A dictionary is a listing of lexemes from the lexicon of one or more specific languages, often arranged Alphabetical order, alphabetically (or by Semitic root, consonantal root for Semitic languages or radical-and-stroke sorting, radical and stroke for Logogram, logographic languages), which may include information on definitions, usage, etymologies, pronunciations, Bilingual dictionary, translation, etc.Webster's New World College Dictionary, Fourth Edition, 2002 It is a Lexicography, lexicographical reference that shows inter-relationships among the data. A broad distinction is made between general and specialized dictionaries. Specialized dictionaries include words in specialist fields, rather than a comprehensive range of words in the language. Lexical items that describe concepts in specific fields are usually called terms instead of words, although there is no consensus whether lexicology and terminology are two different fields of study. In theory, general dictionarie ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Calcium Carbonate
Calcium carbonate is a chemical compound with the chemical formula . It is a common substance found in Rock (geology), rocks as the minerals calcite and aragonite, most notably in chalk and limestone, eggshells, gastropod shells, shellfish skeletons and pearls. Materials containing much calcium carbonate or resembling it are described as calcareous. Calcium carbonate is the active ingredient in agricultural lime and is produced when calcium ions in hard water react with carbonate ions to form limescale. It has medical use as a calcium supplement or as an antacid, but excessive consumption can be hazardous and cause hypercalcemia and digestive issues. Chemistry Calcium carbonate shares the typical properties of other carbonates. Notably, it: *reacts with acids, releasing carbonic acid which quickly disintegrates into carbon dioxide and water: : *releases carbon dioxide upon heating, called a thermal decomposition reaction, or calcination (to above 840 °C in the case of ), t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Calcareous
Calcareous () is an adjective meaning "mostly or partly composed of calcium carbonate", in other words, containing lime (mineral), lime or being chalky. The term is used in a wide variety of Science, scientific disciplines. In zoology ''Calcareous'' is used as an adjectival term applied to anatomical structures which are made primarily of calcium carbonate, in animals such as gastropods, i.e., snails, specifically in relation to such structures as the operculum (gastropod), operculum, the clausilium, and the love dart. The term also applies to the calcium carbonate Test (biology), tests of, often, more-or-less microscopic Foraminifera. Not all tests are calcareous; diatoms and radiolaria have siliceous tests. The molluscs are calcareous organisms, as are the Calcarea, calcareous sponges (Calcarea), that have spicules which are made of calcium carbonate. Additionally, reef-building corals, or Scleractinia, are calcareous organisms that form their rigid skeletal structure th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pomatiidae
The family Pomatiidae is a taxonomic family of small operculate land snails, terrestrial gastropod mollusks that can be found over the warmer parts of the Old World. In the older literature, this family is designated as Pomatiasidae. This family is a lineage closely related to the Littorinidae (periwinkles) common in coastal habitat. They have adapted to terrestrial life and are thus sometimes called "land winkles". They are defined by a chalky operculum at the rear end of the body, the shape of their thick shell and their mouth and a characteristic spiral sculpture. The sexes are separate and can sometimes be recognised because the female shell is slightly larger than the male shell. Taxonomy According to the Taxonomy of the Gastropoda (Bouchet & Rocroi, 2005), the family Pomatiidae consisted of two subfamilies: *subfamily Pomatiinae Newton, 1891 (1828) - synonyms: Cyclostomatidae Menke, 1828; Cyclotopsinae Kobelt & Möllendorff, 1898; Ericiidae Wenz, 1915 *subfamily Ann ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Naticidae
Naticidae, common name moon snails or necklace shells, is a family (biology), family of medium to large-sized predatory sea snails, marine (ocean), marine gastropod molluscs in the clade Littorinimorpha. The shells of the species in this family are mostly globular in shape. Naticidae is the only family in the superfamily Naticoidea. It has been estimated that worldwide there are about 260–270 Holocene, recent species of naticid snails. This group is assumed to have originated in the late Triassic or in the early Jurassic. Members of this family can be recognized by the shape of their shells, distinct appearance, or by their predatory behaviour. Distribution Naticids are widely distributed and occur worldwide and are considered to be a delicate part of the web of nature amongst many others. The greatest Biodiversity, diversity of both species and genera is found in tropical regions. Even so, naticid snails are also plentiful in temperate, Arctic and Antarctic waters. Habitat M ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gastropod
Gastropods (), commonly known as slugs and snails, belong to a large Taxonomy (biology), taxonomic class of invertebrates within the phylum Mollusca called Gastropoda (). This class comprises snails and slugs from saltwater, freshwater, and from the land. There are many thousands of species of sea snails and sea slug, slugs, as well as freshwater snails, freshwater limpets, land snails and slugs. The class Gastropoda is a diverse and highly successful class of mollusks within the phylum Mollusca. It contains a vast total of named species, second only to the insects in overall number. The fossil history of this class goes back to the Furongian, Late Cambrian. , 721 family (taxonomy), families of gastropods are known, of which 245 are extinct and appear only in the fossil record, while 476 are currently neontology, extant living fossil, with or without a fossil record. Gastropoda (previously known as univalves and sometimes spelled "Gasteropoda") are a major part of the phylum Mo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Viviparus Contectus Met Operculum2
''Viviparus'', commonly known as the river snails, is a genus of large, freshwater snails with an operculum, aquatic gastropod molluscs.Bouchet, P. (2014). Viviparus Montfort, 1810. Accessed through: World Register of Marine Species at http://www.marinespecies.org/aphia.php?p=taxdetails&id=154004 on 2014-11-13 They are primitive members of the clade Caenogastropoda. The old name of the genus was ''Paludina''. Distribution This genus is palaearctic in distribution, and is known from the Jurassic to the Recent. Species ''Viviparus'' belongs to the subfamily Viviparinae. Its taxonomy is currently under development and many of its species are often included in other related genera. It includes the following species: * † '' Viviparus achatinoides'' (Deshayes, 1838) * ''Viviparus acerosus'' (Bourguignat, 1862) * † '' Viviparus aitaiensis'' Jekelius, 1932 * † '' Viviparus alexandrieni'' Cobălcescu, 1883 * † '' Viviparus altecarinatus'' Brusina, 1874 * † ''Viviparus alt ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
