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Pisidiid
''Pisidium'' is a genus of very small or minute freshwater clams known as pill clams or pea clams, aquatic bivalve molluscs in the family Sphaeriidae, the pea clams and fingernail clams. In some bivalve classification systems, the family Sphaeriidae is referred to as Pisidiidae, and occasionally ''Pisidium'' species are grouped in a subfamily known as Pisidiinae. ''Pisidium'' and taphonomy In large enough quantities, the minute shells of these bivalves can affect environmental conditions, and this change in conditions can positively affect the ability of organic remains in the immediate environment to fossilize (one aspect of taphonomy). For example, in the Dinosaur Park Formation, the fossil remains of hadrosaur eggshells are rare. This is because the breakdown of tannins from the local coniferous vegetation caused the ancient waters to be acidic, and therefore usually eggshell fragments dissolved in the water before they had a chance to be fossilized. Hadrosaur eggshell fra ...
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Hadrosaur
Hadrosaurids (), or duck-billed dinosaurs, are members of the ornithischian family Hadrosauridae. This group is known as the duck-billed dinosaurs for the flat duck-bill appearance of the bones in their snouts. The ornithopod family, which includes genera such as ''Edmontosaurus'' and ''Parasaurolophus'', was a common group of herbivores during the Late Cretaceous Period. Hadrosaurids are descendants of the Upper Jurassic/Lower Cretaceous iguanodontian dinosaurs and had a similar body layout. Hadrosaurs were among the most dominant herbivores during the Late Cretaceous in Asia and North America, and during the close of the Cretaceous several lineages dispersed into Europe, Africa, South America and Antarctica. Like other ornithischians, hadrosaurids had a predentary bone and a pubic bone which was positioned backwards in the pelvis. Unlike more primitive iguanodonts, the teeth of hadrosaurids are stacked into complex structures known as dental batteries, which acted as effective g ...
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Dinosaur Park Formation
The Dinosaur Park Formation is the uppermost member of the Belly River Group (also known as the Judith River Group), a major geologic unit in southern Alberta. It was deposited during the Campanian stage of the Late Cretaceous, between about 76.5 and 74.4 million years ago. It was deposited in alluvial and coastal plain environments, and it is bounded by the nonmarine Oldman Formation below it and the marine Bearpaw Formation above it.Eberth, D.A. 2005. The geology. In: Currie, P.J., and Koppelhus, E.B. (eds), Dinosaur Provincial Park: A Spectacular Ancient Ecosystem Revealed. Indiana University Press: Bloomington and Indianapolis, p.54-82. . The Dinosaur Park Formation contains dense concentrations of dinosaur skeletons, both articulated and disarticulated, which are often found with preserved remains of soft tissues. Remains of other animals such as fish, turtles, and crocodilians, as well as plant remains, are also abundant. The formation has been named after Dinosaur Pr ...
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Valve (mollusc)
A valve is each articulating part of the shell of a mollusc or another multi-shelled animal such as brachiopods and some crustaceans. Each part is known as a valve or in the case of chitons, a "plate". Members of two classes of molluscs, the Bivalvia (clams) and the Polyplacophora (chitons), have valves. Species within one family of very unusual small sea snails, marine opisthobranch gastropods in the family Juliidae, also have two articulating shells or valves, which resemble those of a bivalve. This exceptional family is commonly known as the bivalved gastropods. Gastropods in general are sometimes called "univalves", because in those that have a shell, the shell is usually in one part. Chitons The valves of chitons are eight dorsal, articulated shell plates, which are frequently coloured and sculpted. After death the girdle that holds the plates together disintegrates and the plates separate. Thus individual plates can be found washed up in beach drift, as shown in the ...
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Pisidium Moitessierianum
''Pisidium moitessierianum'' is a species of minute freshwater clam. It is an aquatic bivalve mollusc in the family Sphaeriidae. Description This species is the smallest of the pea clams or ''Pisidium'' species, and the smallest of any freshwater bivalve, at 1.5 - 2.5 mm. adult size. The shell is long-oval and oblique wedge-shaped with prominent umbos which are slightly behind the midpoint. The umbos are demarcated by a shallow furrow. The surface (periostracum) is silky, with regular concentric striae. Distribution The species is native to Europe but has been introduced to northeastern North America. * Czech Republic – in Bohemia, in Moravia, Horsák M., Juřičková L., Beran L., Čejka T. & Dvořák L. (2010). "Komentovaný seznam měkkýšů zjištěných ve volné přírodě České a Slovenské republiky. nnotated list of mollusc species recorded outdoors in the Czech and Slovak Republics. ''Malacologica Bohemoslovaca'', Suppl. 1: 1-37PDF - endangered (EN ...
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Pisidium Waldeni
''Euglesa waldeni'' is a species of mollusc belonging to the family Sphaeriidae. It is native to Northern Europe. Synonym: * ''Pisidium waldeni'' Kuiper, 1975 (= basionym In the scientific name of organisms, basionym or basyonym means the original name on which a new name is based; the author citation of the new name should include the authors of the basionym in parentheses. The term "basionym" is used in both botan ...) References {{Taxonbar, from=Q101438586 Sphaeriidae Molluscs described in 1975 ...
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Pisidium Supinum
''Pisidium supinum'' is a species of minute freshwater clam, a pea clam, an aquatic bivalve mollusc in the family Sphaeriidae (the fingernail clams and pea clams.) The shell of this species is 3 to 5 mm in size, and is roughly triangular in shape. Distribution Its native distribution is Palearctic. * Czech Republic – in Bohemia, in Moravia, Horsák M., Juřičková L., Beran L., Čejka T. & Dvořák L. (2010). "Komentovaný seznam měkkýšů zjištěných ve volné přírodě České a Slovenské republiky. nnotated list of mollusc species recorded outdoors in the Czech and Slovak Republics. ''Malacologica Bohemoslovaca'', Suppl. 1: 1-37PDF vulnerable (VU) * Germany – endangered (''gefährdet'') * Nordic countries: Denmark, Finland (endangered An endangered species is a species that is very likely to become extinct in the near future, either worldwide or in a particular political jurisdiction. Endangered species may be at risk due to factors such as hab ...
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Pisidium Lilljeborgii
''Pisidium lilljeborgii'' is a species of freshwater bivalve from the family Sphaeriidae. Description A moderately swollen (tumid), trapezoidal shell. The umbos are just behind the mid point and described as fairly narrow. The surface (periostracum) is slightly glossy and has coarse, irregular concentric striae. The colour is grey to brownish white. Pisidium lilljeborgii has a less equilateral shape than ''Pisidium hibernicum'' 3-4.5mm. Distribution and conservation status * Not listed in IUCN red list – not evaluated (NE) * Germany – high endangered (''Stark gefährdet'') * Nordic countries: Denmark, Faroes, Finland, Iceland, Norway and Sweden *Great Britain and IrelandRoy Anderson ,2005 An annotated list of the non-marine molluscs of Britain and Ireland Journal of Conchology, 38 (6): 607–637, (published 2005 References External links''Pisidium lilljeborgii''at Animalbase AnimalBase is a project brought to life in 2004 and is maintained by the University of Göttingen, ...
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Pisidium Henslowanum
''Pisidium henslowanum'' is a species of very small freshwater clam or pea clam, an aquatic bivalve mollusc in the family Sphaeriidae. It is commonly referred to as the Henslow peaclam. Etymology The specific name honours John Stevens Henslow. Description The shell is obliquely oval. It has prominent, narrow umbos well behind the middle and the umbos have oblique raised crests. The surface (periostracum) is silky with fine, even concentric striae. The colour is greyish, especially at the umbos. Widespread but local and uncommon. The size is 3.5-5mm. Distribution Its native distribution is Holarctic. * Czech Republic – in Bohemia, in Moravia, Horsák M., Juřičková L., Beran L., Čejka T. & Dvořák L. (2010). "Komentovaný seznam měkkýšů zjištěných ve volné přírodě České a Slovenské republiky. nnotated list of mollusc species recorded outdoors in the Czech and Slovak Republics. ''Malacologica Bohemoslovaca'', Suppl. 1: 1-37PDF least concern (LC) * Slovak ...
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Lamarck
Jean-Baptiste Pierre Antoine de Monet, chevalier de Lamarck (1 August 1744 – 18 December 1829), often known simply as Lamarck (; ), was a French naturalist, biologist, academic, and soldier. He was an early proponent of the idea that biological evolution occurred and proceeded in accordance with natural laws. Lamarck fought in the Seven Years' War against Prussia, and was awarded a commission for bravery on the battlefield. Posted to Monaco, Lamarck became interested in natural history and resolved to study medicine. Packard (1901), p. 15. He retired from the army after being injured in 1766, and returned to his medical studies. Lamarck developed a particular interest in botany, and later, after he published the three-volume work ''Flore françoise'' (1778), he gained membership of the French Academy of Sciences in 1779. Lamarck became involved in the Jardin des Plantes and was appointed to the Chair of Botany in 1788. When the French National Assembly founded the Muséum ...
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Pisidium Obtusale
''Pisidium obtusale'' is a species of freshwater bivalve from family Sphaeriidae. Description The 2.5–3.5mm. shell is very tumid (swollen). It is an angular-oval shape with broad, rounded umbos which are behind the midpoint. The surface (periostracum) is glossy with fine concentric striae. Numerous pores are visible inside the shell. The colour is whitish to yellowish often coated with a red-brown deposit. Distribution Its native distribution is Holarctic. * Czech Republic – in Bohemia, in Moravia, Horsák M., Juřičková L., Beran L., Čejka T. & Dvořák L. (2010). "Komentovaný seznam měkkýšů zjištěných ve volné přírodě České a Slovenské republiky. nnotated list of mollusc species recorded outdoors in the Czech and Slovak Republics. ''Malacologica Bohemoslovaca'', Suppl. 1: 1-37PDF near threatened (NT) * Germany – (''Arten der Vorwarnliste'') * Nordic countries: Denmark, Faroes, Finland, Iceland, Norway and Sweden *Great Britain and IrelandRoy Anderson ...
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Pisidium Hinzi
''Euglesa hinzi'' is a species of mollusc belonging to the family Sphaeriidae. It is native to Northern Europe. Synonym: * ''Pisidium hinzi'' Kuiper, 1975 (= basionym In the scientific name of organisms, basionym or basyonym means the original name on which a new name is based; the author citation of the new name should include the authors of the basionym in parentheses. The term "basionym" is used in both botan ...) References {{Taxonbar, from=Q101438551 Sphaeriidae Molluscs described in 1975 ...
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Pisidium Dilatatum
''Pisidium dilatatum'' is a species of freshwater bivalve belonging to the family Sphaeriidae Sphaeriidae is a family of small to minute freshwater bivalve molluscs in the order Sphaeriida. In the US, they are commonly known as pea clams or fingernail clams. Heard, William H. 1977. Reproduction of fingernail clams (Sphaeriidae: ''Sphae .... It is widespread in Europe and Asia, from southern Sweden in the west to Lake Baikal in the east. It occurs in oligotrophic lakes. References Sphaeriidae Molluscs of Asia Molluscs of Europe Freshwater animals of Asia Freshwater animals of Europe Molluscs described in 1897 {{bivalve-stub ...
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