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Concavodontinae
Concavodontinae is an extinct subfamily of prehistoric bivalves in the family Praenuculidae. Concavodontinae species lived from the middle Ordovician, Caradoc epoch through the late Ordovician Ashgill epoch.The Paleobiology Database Concavodontinae entry accessed 19 January 2012The Paleobiology Database ''Concavodonta'' entry accessed 19 January 2012 Concavodontinae fossils are found in Europe and South America, and species are thought to have been stationary attached to substrate in sh ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Concavodonta
''Concavodonta'' is an extinct genus of early bivalve in the extinct family Praenuculidae. The genus is one of three genera in the subfamily Concavodontinae. ''Concavodonta'' is known solely from late Ordovician, Caradoc epoch, fossils found in Europe and South America. The genus currently contains three accepted species, ''Concavodonta imbricata'', ''Concavodonta ovalis'' and the type species ''Concavodonta ponderata''. Description ''Concavodonta'' is a small bivalve which was first described in 1972 by Claude Babin and Michel Melou. Generally the shells of ''Concavodonta'' are fairly rounded to ovoid in shape. As the type genus for the subfamily Concavodontinae, the hinge displays the typical chevroning of teeth where the concavity in the chevron faces away from the center of the hinge and the umbo. The adductor muscles for the shell are unequal in shape. The external surface of the shells show regular concentric ornamentation. The type species for the genus, ''Concav ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Emiliodonta
''Emiliodonta'' is an extinct genus of bivalve in the extinct family Praenuculidae. The genus is one of three genera in the subfamily Concavodontinae. ''Emiliodonta'' is known solely from late Ordovician, Caradocian epoch, fossils found in South America. The genus contains a single accepted species, ''Emiliodonta cuerdai''. Description ''Emiliodonta cuerdai'' is a bivalve first described in 1999 by Teresa M. Sánchez from fossils from sediments of the late Middle Ordovician, Caradocian-aged Don Braulio Formation. The formation outcrops on the flank of Sierra de Villicum in the Argentina precordillera.The Paleobiology database "Sierra de Villicum" entry accessed 17 January 2012 Generally the shells of ''Emiliodonta cuerdai'' are rounded and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hemiconcavodonta
''Hemiconcavodonta'' is an extinct genus of bivalve in the extinct family Praenuculidae. The genus is one of three genera in the subfamily Concavodontinae. ''Hemiconcavodonta'' is known solely from late Ordovician, Caradoc epoch, fossils found in South America. The genus currently contains a single accepted species, ''Hemiconcavodonta minuta''. Description ''Hemiconcavodonta minuta'' is a bivalve which was first described in 1999 by Teresa M. Sánchez from fossils from sediments of the late Middle Ordovician, Caradocian-aged Don Braulio Formation. The formation outcrops on the flank of Sierra de Villicum in the Argentina precordillera Precordillera is a Spanish geographical term for hills and mountains lying before a greater range, foothills. The term is derived from ''cordillera'' (mountain range)—literally "pre-mountain range"—and applied usually to the Andes. Some places .... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Praenuculidae
Praenuculidae is an extinct family (biology), family of prehistoric bivalves in the superfamily (taxonomy), superfamily Nuculoidea. Praenuculidae species lived from the early Ordovician, Arenig, Arenig stage through the Early Devonian Emsian, Emsian stage.The Paleobiology Database Praenuculidae entry accessed 11 January 2012 Praenuculidae fossils are found worldwide, present on every continent except Antarctica. Species in this family are thought to have been Sessility (zoology), sessile, attached to the substrate in shallow infaunal marine water environments, where they formed shells of an aragonite composition. The family Praenuculidae was named by A. Lee McAlester in 1969. Description Praenuculidae first eme ...[...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Praenuculinae
Praenuculinae is an extinct subfamily of prehistoric bivalves in the family Praenuculidae. Praenuculinae species lived from the middle Ordovician through the late Devonian.The Paleobiology Database Praenuculinae entry accessed 5 February 2012.The Paleobiology Database ''Praenucula'' entry accessed 5 February 2012. Praenuculinae fossils are found in Europe, Africa, North America and South America, [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Caradoc (age)
The Ordovician ( ) is a geologic period and system, the second of six periods of the Paleozoic Era. The Ordovician spans 41.6 million years from the end of the Cambrian Period million years ago (Mya) to the start of the Silurian Period Mya. The Ordovician, named after the Welsh tribe of the Ordovices, was defined by Charles Lapworth in 1879 to resolve a dispute between followers of Adam Sedgwick and Roderick Murchison, who were placing the same rock beds in North Wales in the Cambrian and Silurian systems, respectively. Lapworth recognized that the fossil fauna in the disputed strata were different from those of either the Cambrian or the Silurian systems, and placed them in a system of their own. The Ordovician received international approval in 1960 (forty years after Lapworth's death), when it was adopted as an official period of the Paleozoic Era by the International Geological Congress. Life continued to flourish during the Ordovician as it did in the earlier Cambrian Perio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Argentina
Argentina (), officially the Argentine Republic ( es, link=no, República Argentina), is a country in the southern half of South America. Argentina covers an area of , making it the second-largest country in South America after Brazil, the fourth-largest country in the Americas, and the eighth-largest country in the world. It shares the bulk of the Southern Cone with Chile to the west, and is also bordered by Bolivia and Paraguay to the north, Brazil to the northeast, Uruguay and the South Atlantic Ocean to the east, and the Drake Passage to the south. Argentina is a federal state subdivided into twenty-three provinces, and one autonomous city, which is the federal capital and largest city of the nation, Buenos Aires. The provinces and the capital have their own constitutions, but exist under a federal system. Argentina claims sovereignty over the Falkland Islands, South Georgia and the South Sandwich Islands, and a part of Antarctica. The earliest recorded ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Prehistoric Bivalves
Prehistory, also known as pre-literary history, is the period of human history between the use of the first stone tools by hominins 3.3 million years ago and the beginning of recorded history with the invention of writing systems. The use of symbols, marks, and images appears very early among humans, but the earliest known writing systems appeared 5000 years ago. It took thousands of years for writing systems to be widely adopted, with writing spreading to almost all cultures by the 19th century. The end of prehistory therefore came at very different times in different places, and the term is less often used in discussing societies where prehistory ended relatively recently. In the early Bronze Age, Sumer in Mesopotamia, the Indus Valley Civilisation, and ancient Egypt were the first civilizations to develop their own scripts and to keep historical records, with their neighbors following. Most other civilizations reached the end of prehistory during the following Iron Age. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Precordillera
Precordillera is a Spanish geographical term for hills and mountains lying before a greater range, foothills. The term is derived from ''cordillera'' (mountain range)—literally "pre-mountain range"—and applied usually to the Andes. Some places usually called precordillera are: *Andean mountains east of the main ranges of Andes in Argentina. It is separated from the much higher Frontal Cordillera to the west by Uspallata Valley in Argentina. Precordillera mountains reach around 3,000 m a.s.l. in Sierras de Villavicencio. *Used all over Chile from north to south as a morphological unit lying just between the Andes and the Intermediate Depression. See also * Geological history of the precordillera terrane The Precordillera terrane of western Argentina is a large mountain range located southeast of the main Andes mountain range. The evolution of the Precordillera is noted for its unique formation history compared to the region nearby. The Cambrian- ... * References {{Geo-term ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Late Ordovician
The Ordovician ( ) is a geologic period and system, the second of six periods of the Paleozoic Era. The Ordovician spans 41.6 million years from the end of the Cambrian Period million years ago (Mya) to the start of the Silurian Period Mya. The Ordovician, named after the Welsh tribe of the Ordovices, was defined by Charles Lapworth in 1879 to resolve a dispute between followers of Adam Sedgwick and Roderick Murchison, who were placing the same rock beds in North Wales in the Cambrian and Silurian systems, respectively. Lapworth recognized that the fossil fauna in the disputed strata were different from those of either the Cambrian or the Silurian systems, and placed them in a system of their own. The Ordovician received international approval in 1960 (forty years after Lapworth's death), when it was adopted as an official period of the Paleozoic Era by the International Geological Congress. Life continued to flourish during the Ordovician as it did in the earlier Cambrian ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
