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Ancistrobasis Monodon
''Ancistrobasis monodon'' is a species of extremely small deep water sea snail, a marine gastropod mollusk in the family Seguenziidae.WoRMS (2013). ''Ancistrobasis monodon'' (Schepman, 1908). Retrieved through: World Register of Marine Species at http://www.marinespecies.org/aphia.php?p=taxdetails&id=492314 on 2013-06-10 Description (Original description by Schepman) The height of the shell attains 4¾ mm. The yellowish-white, perforate, conical shell has slightly convex sides, The six whorls are slightly convex. The nucleus is smooth. The other whorls are sculptured by numerous concentric ribs and spiral lirae, about 9 in number on the penultimate whorl, producing a cancellated appearance. Where they cross, they form small tubercles. The body whorl is angular at the periphery. The flat base of the shell is sculptured by 12 spiral lirae and by radiating riblets, which make the inner 9 lirae beaded, the outer ones being crenulated. The small umbilicus is funnel-shaped, pervious ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mattheus Marinus Schepman
Mattheus Marinus Schepman (17 August 1847 – 19 November 1919) was a Dutch people, Dutch malacologist. He was one of the foremost collectors of mollusc shells in the Netherlands, and was also high on the overall list of European collectors. Dutch collectors developed an interest in natural history specimens that were collected on worldwide expeditions since the 16th century. An interest in conchology led to numerous shell publications. In 1934 the Nederlandse Malacologische Vereniging (Netherlands Malacological Society) was founded. In commemoration of its 75th anniversary, a book honoring in detail the work of Mattheus Schepman was published. His research Schepman was both a collector and a methodical scientist, which combination "made his collection of great value to the entire malacological community." He was given the opportunity to study a collection by Max Carl Wilhelm Weber, Director of the Zoological Museum Amsterdam, Zoölogisch Museum Amsterdam (ZMA). Many of the speci ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sculpture (mollusc)
Sculpture is a feature of many of the shells of mollusks. It is three-dimensional ornamentation on the outer surface of the shell, as distinct from either the basic shape of the shell itself or the pattern of colouration, if any. Sculpture is a feature found in the shells of gastropods, bivalves, and scaphopods. The word "sculpture" is also applied to surface features of the aptychus of ammonites, and to the outer surface of some calcareous opercula of marine gastropods such as some species in the family Trochidae. Sculpture can be concave or convex, incised into the surface or raised from it. Sometimes the sculpture has microscopic detailing. The term "sculpture" refers only to the calcareous outer layer of shell, and does not include the proteinaceous periostracum, which is in some cases textured even when the underlying shell surface is smooth. In many taxa, there is no sculpture on the shell surface at all, apart from the presence of fine growth lines. The sc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
New Caledonia
) , anthem = "" , image_map = New Caledonia on the globe (small islands magnified) (Polynesia centered).svg , map_alt = Location of New Caledonia , map_caption = Location of New Caledonia , mapsize = 290px , subdivision_type = Sovereign state , subdivision_name = , established_title = Annexed by France , established_date = 24 September 1853 , established_title2 = Overseas territory , established_date2 = 1946 , established_title3 = Nouméa Accord , established_date3 = 5 May 1998 , official_languages = French , regional_languages = , capital = Nouméa , coordinates = , largest_city = capital , demonym = New Caledonian , government_type = Devolved parliamentary dependency , leader_title1 = President of France , leader_name1 = Emmanuel Macron , leader_title2 = President of the Government , leader_name2 = Louis Mapou , leader_title3 = President of the Congress , leader_name3 = Roch Wamytan , leader_title4 = High Commissioner , leader_name4 = ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Columella (gastropod)
The columella (meaning "little column") or (in older texts) pillar is a central anatomical feature of a coiled snail shell, a gastropod shell. The columella is often only clearly visible as a structure when the shell is broken, sliced in half vertically, or viewed as an X-ray image. The columella runs from the apex of the shell to the midpoint of the undersurface of the shell, or the tip of the siphonal canal in those shells which have a siphonal canal. If a snail shell is visualized as a cone of shelly material which is wrapped around a central axis, then the columella more or less coincides spatially with the central axis of the shell. In the case of shells that have an umbilicus, the columella is a hollow structure. The columella of some groups of gastropod shells can have a number of plications or folds (the columellar fold, plaits or plicae), which are usually visible when looking to the inner lip into the aperture of the shell. These folds can be wide or narrow, promine ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aperture (mollusc)
The aperture is an opening in certain kinds of mollusc shells: it is the main opening of the shell, where the head-foot part of the body of the animal emerges for locomotion, feeding, etc. The term ''aperture'' is used for the main opening in gastropod shells, scaphopod shells, and also for '' Nautilus'' and ammonite shells. The word is not used to describe bivalve shells, where a natural opening between the two shell valves in the closed position is usually called a '' gape''. Scaphopod shells are tubular, and thus they have two openings: a main anterior aperture and a smaller posterior aperture. As well as the aperture, some gastropod shells have additional openings in their shells for respiration; this is the case in some Fissurellidae (keyhole limpets) where the central smaller opening at the apex of the shell is called an orifice, and in the Haliotidae (abalones) where the row of respiratory openings in the shell are also called orifices. In gastropods In some pros ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Umbilicus (mollusc)
The umbilicus of a shell is the axially aligned, hollow cone-shaped space within the whorls of a coiled mollusc shell. The term umbilicus is often used in descriptions of gastropod shells, i.e. it is a feature present on the ventral (or under) side of many (but not all) snail shells, including some species of sea snails, land snails, and freshwater snails. The word is also applied to the depressed central area on the planispiral coiled shells of ''Nautilus'' species and fossil ammonites. (These are not gastropods, but shelled cephalopods.) In gastropods The spirally coiled whorls of gastropod shells frequently connect to each other by their inner sides, during the natural course of its formation. This results in a more or less solid central axial pillar, known as the columella. The more intimate the contact between the concave side of the whorls is, the more solid the columella becomes. On the other hand, if this connection is less intense, a hollow space inside the whorls ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Body Whorl
The body whorl is part of the morphology of the shell in those gastropod mollusks that possess a coiled shell. The term is also sometimes used in a similar way to describe the shell of a cephalopod mollusk. In gastropods In gastropods, the body whorl, or last whorl, is the most recently formed and largest whorl (or revolution) of a spiral or helical shell, terminating in the aperture. It is called the "body whorl" because most of the body of the soft parts of the animal fits into this whorl. The proportional size of the body whorl in gastropod shells differs greatly according to the actual shell morphology. For shells in which the rate of whorl expansion of each revolution around the axis is very high, the aperture and the body whorl are large, and the shell tends to be low spired. The shell of the abalone is a good example of this kind of shell. The opposite tendency can sometimes create a high spire with very little whorl increase per revolution. In these instances ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Whorl (mollusc)
A whorl is a single, complete 360° revolution or turn in the spiral growth of a mollusc shell. A spiral configuration of the shell is found in numerous gastropods, but it is also found in shelled cephalopods including '' Nautilus'', '' Spirula'' and the large extinct subclass of cephalopods known as the ammonites. A spiral shell can be visualized as consisting of a long conical tube, the growth of which is coiled into an overall helical or planispiral shape, for reasons of both strength and compactness. The number of whorls which exist in an adult shell of a particular species depends on mathematical factors in the geometric growth, as described in D'Arcy Wentworth Thompson's classic 1917 book '' On Growth and Form'', and by David Raup. The main factor is how rapidly the conical tube expands (or flares-out) over time. When the rate of expansion is low, such that each subsequent whorl is not that much wider than the previous one, then the adult shell has numerous whorl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Species
In biology, a species is the basic unit of Taxonomy (biology), 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 reproduction, produce Fertility, fertile offspring, typically by sexual reproduction. Other ways of defining species include their karyotype, DNA sequence, morphology (biology), 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 binomial nomenclature, 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 specifi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
World Register Of Marine Species
The World Register of Marine Species (WoRMS) is a taxonomic database that aims to provide an authoritative and comprehensive list of names of marine organisms. Content The content of the registry is edited and maintained by scientific specialists on each group of organism. These taxonomists control the quality of the information, which is gathered from the primary scientific literature as well as from some external regional and taxon-specific databases. WoRMS maintains valid names of all marine organisms, but also provides information on synonyms and invalid names. It is an ongoing task to maintain the registry, since new species are constantly being discovered and described by scientists; in addition, the nomenclature and taxonomy of existing species is often corrected or changed as new research is constantly being published. Subsets of WoRMS content are made available, and can have separate badging and their own home/launch pages, as "subregisters", such as the ''World List ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Seguenziidae
Seguenziidae is a family of very small deepwater sea snails, marine gastropod mollusks in the superfamily Seguenzioidea (according to the taxonomy of the Gastropoda by Bouchet & Rocroi, 2005).Bouchet, P. (2012). Seguenziidae. Accessed through: World Register of Marine Species at http://www.marinespecies.org/aphia.php?p=taxdetails&id=23116 on 2013-03-26 Distribution Species from this family occur in the Atlantic Ocean, the Pacific Ocean, the Indian Ocean and the Antarctic Ocean, mostly at bathyal and abyssal depths. Only a few species have been found at depths less than 300 m and none at intertidal depths. Description The thin, translucent, white shell has a trochiform shape. They are small or very small. Their maximum height is 22 mm. They are usually nacreous. The inner lip has often a tooth-like fold. The outer lip has characteristically one to three concave notches (except in the genus ''Guttula''). The chitinous operculum is multispiral. The rhipidoglossan r ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
