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Duck Clam
Mactridae, common name the trough shells or duck clams, is a family of saltwater clams, marine bivalve mollusks in the order Venerida. Description These clams have two short siphons, each with a horny sheath. The shell is shaped like a rounded-cornered equilateral triangle and there is a slight gape at the posterior. Each valve bears two cardinal teeth with four lateral teeth on the right valve and two on the left. The foot is white and wedge-shaped. They mostly inhabit the neritic zone. Ecology Trough shells burrow in sand or fine gravel and never in muddy substrates. Genera According to the World Register of Marine Species (2012), this family contains 37 genera: * ''Anatina'' Schumacher, 1817 * '' Austromactra'' Iredale, 1930 * '' Barymactra'' Cossmann in Cossmann & Peyrot, 1909 * '' Coelomactra'' Dall, 1895 * ''Crassula'' Marwick, 1948 * '' Cyclomactra'' Dall, 1895 * ''Darina'' Gray, 1853 * '' Diaphoromactra'' Iredale, 1930 * '' Eastonia'' Gray, 1853 * '' Harvella'' Gray, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cretaceous
The Cretaceous ( ) is a geological period that lasted from about 145 to 66 million years ago (Mya). It is the third and final period of the Mesozoic Era, as well as the longest. At around 79 million years, it is the longest geological period of the entire Phanerozoic. The name is derived from the Latin ''creta'', "chalk", which is abundant in the latter half of the period. It is usually abbreviated K, for its German translation ''Kreide''. The Cretaceous was a period with a relatively warm climate, resulting in high eustatic sea levels that created numerous shallow inland seas. These oceans and seas were populated with now- extinct marine reptiles, ammonites, and rudists, while dinosaurs continued to dominate on land. The world was ice free, and forests extended to the poles. During this time, new groups of mammals and birds appeared. During the Early Cretaceous, flowering plants appeared and began to rapidly diversify, becoming the dominant group of plants across the Earth b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Carl Linnaeus
Carl Linnaeus (; 23 May 1707 – 10 January 1778), also known after his ennoblement in 1761 as Carl von Linné Blunt (2004), p. 171. (), was a Swedish botanist, zoologist, taxonomist, and physician who formalised binomial nomenclature, the modern system of naming organisms. He is known as the "father of modern taxonomy". Many of his writings were in Latin; his name is rendered in Latin as and, after his 1761 ennoblement, as . Linnaeus was born in Råshult, the countryside of Småland, in southern Sweden. He received most of his higher education at Uppsala University and began giving lectures in botany there in 1730. He lived abroad between 1735 and 1738, where he studied and also published the first edition of his ' in the Netherlands. He then returned to Sweden where he became professor of medicine and botany at Uppsala. In the 1740s, he was sent on several journeys through Sweden to find and classify plants and animals. In the 1750s and 1760s, he continued to collect an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mactra
''Mactra'' is a large genus of medium-sized marine bivalve mollusks or clams, commonly known as trough shells or duck clams. ''Mactra'' is the type genus within the family Mactridae.MolluscaBase eds. (2021). MolluscaBase. Mactra Linnaeus, 1767. Accessed through: World Register of Marine Species at: http://www.marinespecies.org/aphia.php?p=taxdetails&id=138158 on 2021-06-03 The word "trough" in the common name refers to the fact that all ''Mactra'' shells have a large ligamental pit at the hinge line, which in life contains a large internal ligament. Most bivalves in other families have an external ligament instead. Species * ''Mactra chinensis'' Philippi, 1846 * ''Mactra glabrata'' Linnaeus, 1767 * '' Mactra glauca'' Born, 1778 * '' Mactra grandis'' (Gmelin, 1791) * '' Mactra guidoi'' Signorelli & F. Scarabino, 2010 * '' Mactra isabelleana'' d'Orbiginny, 1846 * '' Mactra lilacea'' Lamarck, 1818 * ''Mactra quadrangularis'' Reeve, 1854 * '' Mactra sauliana'' Gray, 1838 * ''Mac ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lutraria
''Lutraria'' is a genus of medium-sized marine bivalve mollusks or clams, commonly known as otter shells. Characteristics Members of this genus have large, elongated oval shells with two equal sized valves. The anterior end is somewhat sharply curved but the posterior end is more rounded. The valves gape slightly at both ends, more so at the posterior end. The shell is fairly thick and is sculptured with fine concentric lines corresponding to periods of growth. The basic colour is white and the periostracum is brown, but the latter is usually abraded. The interior surface of the valves is glossy white. The beaks are blunt and situated slightly closer to the anterior end. The ligament is small and largely internal. The foot is small and the siphons are long and are housed in a common horny sheath for most of their length. Biology These mollusks live buried in sand to a depth of about , usually below low water mark, with their siphons extended to the sea bed. As they grow they bu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
