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Rhomboteuthis Lehmani
'' Rhomboteuthis lehmani'' is an extinct species of squid, currently the only described member of its genus. ''R. lehmani'' is known from the Lower Callovian (165–164 Ma) of Voulte-sur-Rhône, Ardèche, France. Radiography was used to locate the position of the ink sac and gladius ''Gladius'' () is a Latin word meaning "sword" (of any type), but in its narrow sense it refers to the sword of ancient Roman foot soldiers. Early ancient Roman swords were similar to those of the Greeks, called '' xiphe'' (plural; singular ''xi ... (pen) of the pictured specimen. References * Fischer, J.-C. & B. Riou 1982. Les teuthoïdes (Cephalopoda, Dibranchiata) du Callovien inférieur de la Voulte-sur-Rhône (Ardèche, France). ''Annales de Paléontologie'' 68(4): 295–325. * Fischer, J.-C. 2003. Invertébrés remarquables du Callovien inférieur de la Voulte-sur-Rhône (Ardèche, France). ''Annales de Paléontologie'' 89: 223–252. Jurassic cephalopods Squid Fossils of France ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Callovian
In the geologic timescale, the Callovian is an age and stage in the Middle Jurassic, lasting between 166.1 ± 4.0 Ma (million years ago) and 163.5 ± 4.0 Ma. It is the last stage of the Middle Jurassic, following the Bathonian and preceding the Oxfordian. Stratigraphic definitions The Callovian Stage was first described by French palaeontologist Alcide d'Orbigny in 1852. Its name derives from the latinized name for Kellaways Bridge, a small hamlet 3 km north-east of Chippenham, Wiltshire, England. The base of the Callovian is defined as the place in the stratigraphic column where the ammonite genus ''Kepplerites'' first appears, which is the base of the biozone of '' Macrocephalites herveyi''. A global reference profile (a GSSP) for the base had in 2009 not yet been assigned. The top of the Callovian (the base of the Oxfordian) is at the first appearance of ammonite species '' Brightia thuouxensis''. Subdivision The Callovian is often subdivided into three substages ( ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ardèche
Ardèche (; oc, Ardecha; frp, Ardecha) is a department in the Auvergne-Rhône-Alpes region of Southeastern France. It is named after the river Ardèche and had a population of 328,278 as of 2019.Populations légales 2019: 07 Ardèche INSEE Its is in Privas, but its largest city is Annonay. History Prehistory and ancient history [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Jurassic Cephalopods
The Jurassic ( ) is a geologic period and stratigraphic system that spanned from the end of the Triassic Period million years ago (Mya) to the beginning of the Cretaceous Period, approximately Mya. The Jurassic constitutes the middle period of the Mesozoic Era and is named after the Jura Mountains, where limestone strata from the period were first identified. The start of the Jurassic was marked by the major Triassic–Jurassic extinction event, associated with the eruption of the Central Atlantic Magmatic Province. The beginning of the Toarcian Stage started around 183 million years ago and is marked by an extinction event associated with widespread oceanic anoxia, ocean acidification, and elevated temperatures likely caused by the eruption of the Karoo-Ferrar large igneous provinces. The end of the Jurassic, however, has no clear boundary with the Cretaceous and is the only boundary between geological periods to remain formally undefined. By the beginning of the Jurassic, t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rhomboteuthis Lehmani
'' Rhomboteuthis lehmani'' is an extinct species of squid, currently the only described member of its genus. ''R. lehmani'' is known from the Lower Callovian (165–164 Ma) of Voulte-sur-Rhône, Ardèche, France. Radiography was used to locate the position of the ink sac and gladius ''Gladius'' () is a Latin word meaning "sword" (of any type), but in its narrow sense it refers to the sword of ancient Roman foot soldiers. Early ancient Roman swords were similar to those of the Greeks, called '' xiphe'' (plural; singular ''xi ... (pen) of the pictured specimen. References * Fischer, J.-C. & B. Riou 1982. Les teuthoïdes (Cephalopoda, Dibranchiata) du Callovien inférieur de la Voulte-sur-Rhône (Ardèche, France). ''Annales de Paléontologie'' 68(4): 295–325. * Fischer, J.-C. 2003. Invertébrés remarquables du Callovien inférieur de la Voulte-sur-Rhône (Ardèche, France). ''Annales de Paléontologie'' 89: 223–252. Jurassic cephalopods Squid Fossils of France ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gladius (cephalopod)
The gladius (plural: ''gladii''), or pen, is a hard internal bodypart found in many cephalopods of the superorder Decapodiformes (particularly squids) and in a single extant member of the Octopodiformes, the vampire squid (''Vampyroteuthis infernalis''). It is so named for its superficial resemblance to the Roman short sword of the same name, and is a vestige of the ancestral mollusc shell, which was external. The gladius is located dorsally within the mantle and usually extends for its entire length. Composed primarily of chitin, it lies within the shell sac, which is responsible for its secretion. Gladii are known from a number of extinct cephalopod groups, including teudopseids (''e.g.'' '' Actinosepia'', '' Glyphiteuthis'', '' Muensterella'', '' Palaeololigo'', '' Teudopsinia'', ''Teudopsis'', and ''Trachyteuthis''), loligosepiids (''e.g.'' '' Geopeltis'', '' Jeletzkyteuthis'', and '' Loligosepia''), and prototeuthids (''e.g.'' ''Dorateuthis'', '' Paraplesioteuthis'', ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ink Sac
An ink sac is an anatomical feature that is found in many cephalopod mollusks used to produce the defensive cephalopod ink. With the exception of nocturnal and very deep water cephalopods, all Coleoidea (squid, octopus and cuttlefish) which dwell in light conditions have an ink sac, which can be used to expel a cloud of dark ink in order to confuse predators. The ink sac is a muscular bag which originated as an extension of the hind gut; it is a modified hypobranchial gland.Nair, J.R., D. Pillai, S.M. Joseph, P. Gomathi, P.V. Senan & P.M. Sherief (2011). ''Indian Journal of Geo-Marine Sciences'' 40(1): 13–27. It lies beneath the gut and opens into the anus, into which its contents – almost pure melanin – can be squirted; its proximity to the base of the funnel means that the ink can be distributed by ejected water as the cephalopod uses its jet propulsion. The ejected cloud of melanin is bound by mucus Mucus ( ) is a slippery aqueous secretion produced by, and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Radiography
Radiography is an imaging technique using X-rays, gamma rays, or similar ionizing radiation and non-ionizing radiation to view the internal form of an object. Applications of radiography include medical radiography ("diagnostic" and "therapeutic") and industrial radiography. Similar techniques are used in airport security (where "body scanners" generally use backscatter X-ray). To create an image in conventional radiography, a beam of X-rays is produced by an X-ray generator and is projected toward the object. A certain amount of the X-rays or other radiation is absorbed by the object, dependent on the object's density and structural composition. The X-rays that pass through the object are captured behind the object by a detector (either photographic film or a digital detector). The generation of flat two dimensional images by this technique is called projectional radiography. In computed tomography (CT scanning) an X-ray source and its associated detectors rotate around the su ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
France
France (), officially the French Republic ( ), is a country primarily located in Western Europe. It also comprises of Overseas France, overseas regions and territories in the Americas and the Atlantic Ocean, Atlantic, Pacific Ocean, Pacific and Indian Oceans. Its Metropolitan France, metropolitan area extends from the Rhine to the Atlantic Ocean and from the Mediterranean Sea to the English Channel and the North Sea; overseas territories include French Guiana in South America, Saint Pierre and Miquelon in the North Atlantic, the French West Indies, and many islands in Oceania and the Indian Ocean. Due to its several coastal territories, France has the largest exclusive economic zone in the world. France borders Belgium, Luxembourg, Germany, Switzerland, Monaco, Italy, Andorra, and Spain in continental Europe, as well as the Kingdom of the Netherlands, Netherlands, Suriname, and Brazil in the Americas via its overseas territories in French Guiana and Saint Martin (island), ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Jean-Claude Fischer
Jean-Claude is a French masculine given name. Notable people with the name include: * Jean-Claude Ades, an Italian electronic music producer * Jean-Claude Alibert (died 2020), a French racing driver * Jean-Claude Amiot (born 1939), a French composer, music professor and conductor * Jean-Claude Andruet (born 1942), a retired French professional rally driver * Jean-Claude Bajeux (1931–2011), a professor and director of the Ecumenical Center for Human Rights in Port-au-Prince, Haiti * Jean-Claude Baker (1943–2015), a French-born American restaurateur * Jean-Claude Bastos de Morais (born 1967), a Swiss entrepreneur with strong connections to Angola * Jean-Claude Beaulieu (born 1944), a member of the National Assembly of France * Jean-Claude Bergeron (born 1968), a retired Canadian ice hockey goaltender * Jean-Claude Bertrand (born 1954), a retired French badminton player * Jean-Claude Biver (born 1949), the CEO, board member and minority shareholder of Hublot * Jean-Claude Blanc (bo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Annum
A year or annus is the orbital period of a planetary body, for example, the Earth, moving in its orbit around the Sun. Due to the Earth's axial tilt, the course of a year sees the passing of the seasons, marked by change in weather, the hours of daylight, and, consequently, vegetation and soil fertility. In temperate and subpolar regions around the planet, four seasons are generally recognized: spring, summer, autumn and winter. In tropical and subtropical regions, several geographical sectors do not present defined seasons; but in the seasonal tropics, the annual wet and dry seasons are recognized and tracked. A calendar year is an approximation of the number of days of the Earth's orbital period, as counted in a given calendar. The Gregorian calendar, or modern calendar, presents its calendar year to be either a common year of 365 days or a leap year of 366 days, as do the Julian calendars. For the Gregorian calendar, the average length of the calendar year (the mea ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Genus
Genus ( plural genera ) is a taxonomic rank used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In the hierarchy of biological classification, genus comes above species and below family (taxonomy), family. In binomial nomenclature, the genus name forms the first part of the binomial species name for each species within the genus. :E.g. ''Panthera leo'' (lion) and ''Panthera onca'' (jaguar) are two species within the genus ''Panthera''. ''Panthera'' is a genus within the family Felidae. The composition of a genus is determined by taxonomy (biology), taxonomists. The standards for genus classification are not strictly codified, so different authorities often produce different classifications for genera. There are some general practices used, however, including the idea that a newly defined genus should fulfill these three criteria to be descriptively useful: # monophyly – all descendants ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
