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Tectus Royanus
''Tectus royanus'' is a species of sea snail, a marine gastropod mollusk in the family Tegulidae.Rosenberg, G. (2012). ''Tectus royanus''. Accessed through: World Register of Marine Species at http://www.marinespecies.org/aphia.php?p=taxdetails&id=592808 on 2012-09-01 Description The height of the shell attains 80 mm, its major diameter 97 mm. Dimensions of largest known shell 101 mm x 102 mm. The large, massive, imperforate shell has a pyramidal shape. In adult shells the upper surface is invariably covered with algae, coralline and other, while the base usually supports a colony of '' Serpula''. The sculpture of these adult shells is scarcely distinguishable. Young shells, however, show the sculpture. The suture is well marked. The (more than 12) whorls are subscalar. The 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 de ...
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Tom Iredale
Tom Iredale (24 March 1880 – 12 April 1972) was an English-born ornithologist and malacologist who had a long association with Australia, where he lived for most of his life. He was an autodidact who never went to university and lacked formal training. This was reflected in his later work; he never revised his manuscripts and never used a typewriter. Early life Iredale was born at Stainburn, Workington in Cumberland, England. He was apprenticed to a pharmacist from 1899 to 1901, and used to go bird watching and egg collecting in the Lake District with fellow chemist William Carruthers Lawrie. New Zealand Iredale emigrated to New Zealand following medical advice, as he had health issues. He may possibly have had tuberculosis. According to a letter to Will Lawrie dated 25 January 1902, he arrived in Wellington, New Zealand in December 1901, and travelled at once on to Lyttelton and Christchurch. On his second day in Christchurch, he discovered that in the Foreign Natural Hi ...
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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 ...
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Tectus
''Tectus'' is a genus of sea snails, marine gastropod mollusks in the family Tegulidae. Description The shell has a pyramidal shape. Its base is flat, without false-umbilicus. The rhomboidal aperture is very oblique, angular, and wider than long. The outer lip is lirate within. The columella is very short, vertical, with a strong spiral fold, ending anteriorly in a knob or point. Distribution This marine genus has a wide distribution. It occurs in the Persian Gulf, the Red Sea, in the Central and East Indian Ocean and off East Africa, Oceania, Indo-China, Indo-Malaysia, the Philippines, East India, Australia ( New South Wales, Northern Territory, Queensland, Western Australia), Kermadec Islands, New Caledonia, Anadaman Islands. Species Species within the genus ''Tectus'' include: * † ''Tectus altavillensis'' (Defrance, 1828) * ''Tectus architectonicus'' A. Adams, 1853 * † ''Tectus athenasi'' (Vasseur, 1882) * † ''Tectus aulacophorus'' (Cossmann & Pissarro ...
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Kermadec Islands
The Kermadec Islands ( mi, Rangitāhua) are a subtropical island arc in the South Pacific Ocean northeast of New Zealand's North Island, and a similar distance southwest of Tonga. The islands are part of New Zealand. They are in total area and uninhabited, except for the permanently manned Raoul Island Station, the northernmost outpost of New Zealand. The islands are listed with the New Zealand outlying islands. The islands are an immediate part of New Zealand, but not part of any region or district, but instead an ''Area Outside Territorial Authority''. Toponymy The islands were named after the Breton captain Jean-Michel Huon de Kermadec, who visited the islands as part of the d'Entrecasteaux expedition in the 1790s. The topographic particle "Kermadec" is of Breton origin and is a lieu-dit in Pencran in Finistère where '' ker'' means village, residence and madec a proper name derived from '' mad'' (which means 'good') with the suffix '' -ec'', used to form a ...
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Tectus Pyramis
''Tectus pyramis'', common name the pyram top shell, is a species of sea snail, a marine gastropod mollusk in the family Turbinidae, the turban snails. Description The size of the shell varies between 45 mm and 105 mm. The imperforate, solid, thick shell has a strictly conical shape. The spire is more or less attenuated above. The apex is acute. The color of the shell is yellowish or grayish, more or less mottled and marbled with green or brown, the base is white, green or brown. The shell contains 12–14 whorls. The upper ones are slightly extended outwards and plicate, tuberculate or undulating at the sutures. The folds or tubercles are obsolete on the lower whorls. The upper whorls are encircled with one or two spiral series of small tubercles or beads, which are increased to about five series on the middle whorls. The body whorl is beaded, but smoother than the preceding, or radiately finely wrinkled, or nearly smooth, angulate at the periphery. The base of ...
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Operculum (gastropod)
The operculum (; ) is a corneous or calcareous anatomical structure like a trapdoor that exists in many (but not all) groups of sea snails and freshwater snails, and also in a few groups of land snails; the structure is found in some marine and freshwater gastropods, and in a minority of terrestrial gastropods, including the families Helicinidae, Cyclophoridae, Aciculidae, Maizaniidae, Pomatiidae, etc. The operculum is attached to the upper surface of the foot and in its most complete state, it serves as a sort of "trapdoor" to close the aperture of the shell when the soft parts of the animal are retracted. The shape of the operculum varies greatly from one family of gastropods to another. It is fairly often circular, or more or less oval in shape. In species where the operculum fits snugly, its outline corresponds exactly to the shape of the aperture of the shell and it serves to seal the entrance of the shell. Many families have opercula that are reduced in size, and which a ...
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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 ...
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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 ...
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Lip (gastropod)
In the shell of gastropod mollusks (a snail shell), the lip is the free margin of the peristome (synonym: peritreme) or aperture (the opening) of the gastropod shell. In dextral (right-handed) shells (most snail shells are right-handed), the right side or outer side of the aperture is known as the outer lip (''labrum''). The left side of the aperture is known as the inner lip or columellar lip (''labium'') if there is a pronounced lip there. In those species where there is no pronounced lip, the part of the body whorl that adjoins the aperture is known as the parietal wall. The outer lip is usually thin and sharp in immature shells, and in some adults (e.g. the land snails '' Helicella'' and ''Bulimulus''). However, in some other land snails and in many marine species the outer lip is ''thickened'' (also called ''callused''), or ''reflected'' (turned outwards). In some other marine species it is curled inwards (''inflected''), as in the cowries such as '' Cypraea''. It can also ...
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Apex (mollusc)
In anatomy, an apex ( adjectival form: apical) is part of the shell of a mollusk. The apex is the pointed tip (the oldest part) of the shell of a gastropod, scaphopod, or cephalopod. The apex is used in end-blown conches. Gastropods The word "apex" is most often used to mean the tip of the spire of the shell of a gastropod. The apex is the first-formed, and therefore the oldest, part of the shell. To be more precise, the apex would usually be where the tip of the embryonic shell or protoconch is situated, if that is still present in the adult shell (often it is lost or eroded away). Coiled gastropod shells The phrase apical whorls, or protoconch, means the whorls that constitute the embryonic shell at the apex of the shell, especially when this is clearly distinguishable from the later whorls of the shell, otherwise known as the teleoconch. Comparison of the apical part and the whole shell of '' Otukaia kiheiziebisu'': File:Calliostoma kiheiziebisu apex.png File:Calli ...
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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 ...
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Suture (anatomy)
In anatomy, a suture is a fairly rigid joint between two or more hard elements of an organism, with or without significant overlap of the elements. Sutures are found in the skeletons or exoskeletons of a wide range of animals, in both invertebrates and vertebrates. Sutures are found in animals with hard parts from the Cambrian period to the present day. Sutures were and are formed by several different methods, and they exist between hard parts that are made from several different materials. Vertebrate skeletons The skeletons of vertebrate animals (fish, amphibians, reptiles, birds, and mammals) are made of bone, in which the main rigid ingredient is calcium phosphate. Cranial sutures The skulls of most vertebrates consist of sets of bony plates held together by cranial sutures. These sutures are held together mainly by Sharpey's fibers which grow from each bone into the adjoining one. Sutures in the ankles of land vertebrates In the type of crurotarsal ankle which is fou ...
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