Ordovician (ordovician period, ordovician), the geological age of the name (primitive vertebrates appear) Paleozoic second century, began dating back 500 million years, continuing a 6500 years. Ordovician (ordovician, symbol o) is the geological age of a century, beginning in the isotopic age 488.3 ± 1.7 million years (ma), ending at 443.7 ± 1.5ma. Ordovician (ordovician) is on the geology, Paleozoic billion five million to four hundred thirty-eight million years ago, this time can be divided into three periods - Early Ordovician (550 million to four hundred seventy-eight million years ago), the mid-Ordovician (four hundred seventy-eight million to four hundred fifty-three million years ago) and the Late Ordovician (four hundred fifty-three million to four hundred million thirty-eight million years ago). Ordovician also points early, middle and late three World. Ordovician history of Shanghai is to invade one of the most extensive period. In the interior floor plate area, sea widespread, the performance of the coastal shallow marine carbonate rocks are widely developed in the plate boundary activity trough area for deep water environment, forming a large thickness of shallow, deep clastic sedimentary sedimentary and volcanic eruptions. There had been a late Ordovician glacial larger scale, the distribution range includes Africa, especially North Africa, South America, Argentina, Bolivia and southern Europe, Spain and France.
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Name of source
"Ordovician" term in 1879 by the British geologist proposed Rapp Worth (c.lapworth), on behalf of the UK exposed arenig (arenig) Mountains eastward through the formation of North Wales, located in the Cambrian between the Silurian strata. Because this region is an ancient tribal Ordovician (ordovices) residence, hence the name.
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Historical Evolution
At that time a mild climate, shallow widespread in many parts of the world (including our most places) are masked shallow water. Unprecedented development of marine organisms. Trilobite fossils, graptolites (graptolites), brachiopods, echinoderms sea Ringo class (cystoides), molluscs Nautilus class (nautilites) the most common coral, bryozoans, crinoids, ostracods and also a lot of tooth-shaped stone. Eurypterid arthropods in the class (eutypterids) and jawless vertebrates [such as armor fish (os-tracoderms)] etc. have appeared. Lower marine plants continue to develop. Cambrian Ordovician more prosperous than the biosphere, the unprecedented development of marine invertebrates, which graptolites, trilobites, brachiopods Nautilus classes and most importantly, coelenterates coral, stromatoporoid , Ringo sea echinoderms, crinoids, arthropods in ostracods, bryozoans, also began large numbers. Mid-Ordovician, appeared in the original class of vertebrates different turtle in North America, the Rocky Mountain region - Star turtle and fish significantly pleats in the southern hemisphere in Australia, there have been different snapper category. Plants still dominated marine algae. Ordovician (5.1-4.38 million years ago) - marine invertebrates animal matter heyday. In the Ordovician vast ocean, marine invertebrates unprecedented prosperity, living with a lot of various categories of invertebrates. In addition to the Cambrian began to flourish taxa, some other groups have been further developed, including graptolites, corals, brachiopods, crinoids, bryozoans, and molluscs.
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Typical biological
Ordovician marine organisms is the earliest ancestor of the modern era of animals. Coral and starfish ancient animals called stellate grow on the ocean floor. Submarine shelled animals including oysters associated with modern mollusks, looks like brachiopods and mollusks shell curl gastropods. Cephalopods - squid extant cousins - quick swim across the seabed in search of game. But the biggest emerging animal is like jawless fish Saca Bamba. Jawless, such as hair concept in South America Saca Bamba fish, is one of the earliest vertebrates on Earth. The pair is still no animal species of life on land. · Fish The first is a jawless fish. They do not have the jaw, mouth very wide, long edge with a strange head bone plate. Perhaps these bony plates are generating organs, or to feel an electric shock from predators. Feeding method jawless are tiny animals containing water and sediment suction mouth. They may be the tail up in the sea to swim. · Trilobites Ordovician sea life with more than 500 kinds of trilobites. Although this kind Cambrian period of no more, but the number is still enormous. This is one of today trilobite fossils so common cause. Trilobite fossils are easy to find, not only because of their large number, but also because they are regularly stripped shell. With the growth of the animal, shell falling into the ancient seabed, often buried, turned into fossils. From Russia to Morocco to the United States, in marine rocks around the world have discovered thousands of different trilobites. Some with long spines to protect against predators, and some will be long in the skillet eyes, so that when they are buried in the sediment where it can still see outside. Trilobite can swim or crawl on the seabed. But the way they might like predator defense today armadillo as the shell body curled up into a ball. We know trilobites predation by other marine life, as we often found bite marks on the trilobite fossils. The rise may have prompted many jaw fish extinct trilobites. But some trilobites survived until 251 million years ago when the greatest extinction disaster. · Graptolites Ordovician graptolites is the most exotic marine fauna, since they are already thriving breeding started early Ordovician widely distributed. Stone is a kind of pen tiny worm-like creatures, they like today, like coral colony life. Graptolites whole population is just 5 cm long, they are drifting in the sea, eat plankton, and today a lot of whales eat tiny marine organisms is the same. Graptolites for scientists are particularly important because they are in a longer period of gradual change. Scientists can determine the age of fossils of other marine life found in the pen according to the kind of common stone. · Conodonts What conodonts are? Scientists in nearly 140 years time have been asking this question. Conodont small research only under a microscope. Most of them shaped like an elongated cone, something that looks like a pointed rake or comb, small stick or some other like jagged edges uneven, and even like leaves. They are tiny animals, shells or slightly larger animal's teeth? Scientists also suggested that they might be, worms, or part of the long tentacles of the animal fish. In 1995, the mystery was finally solved. Produced in Scotland and South Africa fossils show no conodonts from the upper jaw bone and fish-shaped animals. This animal can grow up to 5 cm, looks like a long with protruding eyes and a tail fin of a small eel. At the bottom of each individual head has many conodonts for digging or biting. · Brachiopods Brachiopods Austrian rapid evolution in this period, most of the groups have appeared, no hinge type, chitin shells of brachiopods gradually decline, calcareous shell has hinged class is very popular. Brachiopods first glance looks like bivalves, but it did not and the size of their shells and curves are not the same matter much. Brachiopods hinge beak to handle meat fixation. Brachiopods are relatively rare, but in the 500 million to 450 million years ago, they are far more common bivalves. · Nautilus Nautilus into prosperous times, they are a huge body, was ferocious carnivorous marine animals; due to the large carnivorous Nautilus class appeared to defend, trilobites in the chest, tail grows many acupuncture to avoid predators attacks or swallowed. · Coral Coral appeared in large numbers since the beginning of the Middle Ordovician, coral complex body though still relatively primitive, but it has been able to form a small reef. Due to the great development of marine invertebrates, when the former Cambrian stromatolites very prosperous sharp decline in the Ordovician. · Bryozoans Bryozoans appeared in the early Ordovician, fast evolution, species and more. There dendritic Nicole Johnson bryozoans (nicholsonella), climbing bryozoans (batostoma): Wai massive ancient god bryozoans (dianulites), thin-bedded becomes hidden bryozoans (trepocryptopora). · Other In the late Ordovician period, about 480 million years ago, for the first time a reliable terrestrial vertebrates - freshwater jawless fish; freshwater plants presumably also has appeared in the Ordovician.
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Typical biological
Ordovician marine organisms is the earliest ancestor of the modern era of animals. Coral and starfish ancient animals called stellate grow on the ocean floor. Submarine shelled animals including oysters associated with modern mollusks, looks like brachiopods and mollusks shell curl gastropods. Cephalopods - squid extant cousins - quick swim across the seabed in search of game. But the biggest emerging animal is like jawless fish Saca Bamba. Jawless, such as hair concept in South America Saca Bamba fish, is one of the earliest vertebrates on Earth. The pair is still no animal species of life on land. · Fish The first is a jawless fish. They do not have the jaw, mouth very wide, long edge with a strange head bone plate. Perhaps these bony plates are generating organs, or to feel an electric shock from predators. Feeding method jawless are tiny animals containing water and sediment suction mouth. They may be the tail up in the sea to swim. · Trilobites Ordovician sea life with more than 500 kinds of trilobites. Although this kind Cambrian period of no more, but the number is still enormous. This is one of today's fossil trilobite trilobites so common cause. Trilobite fossils are easy to find, not only because of their large number, but also because they are regularly stripped shell. With the growth of the animal, shell falling into the ancient seabed, often buried, turned into fossils. From Russia to Morocco to the United States, in marine rocks around the world have discovered thousands of different trilobites. Some with long spines to protect against predators, and some will be long in the skillet eyes, so that when they are buried in the sediment where it can still see outside. Trilobite can swim or crawl on the seabed. But the way they might like predator defense today armadillo as the shell body curled up into a ball. We know trilobites predation by other marine life, as we often found bite marks on the trilobite fossils. The rise may have prompted many jaw fish extinct trilobites. But some trilobites survived until 251 million years ago when the greatest extinction disaster. · Graptolites Ordovician graptolites is the most exotic marine fauna, since they are already thriving breeding started early Ordovician widely distributed. Stone is a kind of pen tiny worm-like creatures, they like today, like coral colony life. Graptolites whole population is just 5 cm long, they are drifting in the sea, eat plankton, and today a lot of whales eat tiny marine organisms is the same. Graptolites for scientists are particularly important because they are in a longer period of gradual change. Scientists can determine the age of fossils of other marine life found in the pen according to the kind of common stone. · Conodonts What conodonts are? Scientists in nearly 140 years time have been asking this question. Conodont small research only under a microscope. Most of them shaped like an elongated cone, something that looks like a pointed rake or comb, small stick or some other like jagged edges uneven, and even like leaves. They are tiny animals, shells or slightly larger animal's teeth? Scientists also suggested that they might be, worms, or part of the long tentacles of the animal fish. In 1995, the mystery was finally solved. Produced in Scotland and South Africa fossils show no conodonts from the upper jaw bone and fish-shaped animals. This animal can grow up to 5 cm, looks like a long with protruding eyes and a tail fin of a small eel. At the bottom of each individual head has many conodonts for digging or biting. · Brachiopods Brachiopods Austrian rapid evolution in this period, most of the groups have appeared, no hinge type, chitin shells of brachiopods gradually decline, calcareous shell has hinged class is very popular. Brachiopods first glance looks like bivalves, but it did not and the size of their shells and curves are not the same matter much. Brachiopods hinge beak to handle meat fixation. Brachiopods are relatively rare, but in the 500 million to 450 million years ago, they are far more common bivalves. · Nautilus Nautilus into prosperous times, they are a huge body, was ferocious carnivorous marine animals; due to the large carnivorous Nautilus class appeared to defend, trilobites in the chest, tail grows many acupuncture to avoid predators attacks or swallowed. · Coral Coral appeared in large numbers since the beginning of the Middle Ordovician, coral complex body though still relatively primitive, but it has been able to form a small reef. Due to the great development of marine invertebrates, when the former Cambrian stromatolites very prosperous sharp decline in the Ordovician. · Bryozoans Bryozoans appeared in the early Ordovician, fast evolution, species and more. There dendritic Nicole Johnson bryozoans (NICHOLSONELLA), climbing bryozoans (BATOSTOMA): Wai massive ancient god bryozoans (DIANULITES), thin-bedded becomes hidden bryozoans (TREPOCRYPTOPORA). Bivalves Bivalves Like extant shelled animals like clams, the body is divided into two identical halves. No amount of class The first is a jawless fish. They do not have the jaw, mouth very wide, long edge with a strange head bone plate. Perhaps these bony plates are generating organs, or to feel an electric shock from predators. Feeding method jawless are tiny animals containing water and sediment suction mouth. They may be the tail up in the sea to swim. · Other In the late Ordovician period, about 480 million years ago, for the first time a reliable terrestrial vertebrates - freshwater jawless fish; freshwater plants presumably also has appeared in the Ordovician.
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Encyclopedia
Aotaoji Ordovician Ordovician Period Paleozoic second century, began about 500 million years ago, ending at 440 million years ago. Strata formed during this period, said the Ordovician, located above the Cambrian, Silurian under the Department. Ordovician British geologist C. Rapp Worth in 1879 with Ordovices named, Ordovices is the name of an ancient nation of Wales. "Ordovician" word lines Ordovices Japanese Chinese transliteration. Including the original part of the Ordovician A. Sedgwick named the Cambrian and RI Johnson named Mo enterprises repeat part two Silurian strata. Ordovician held in Copenhagen in 1960, the 21th International Geological Congress formally adopted. Ordovician strata are generally divided into three World: Early Ordovician, Middle Ordovician and Late Ordovician, corresponding to Lower Ordovician strata, Middle Ordovician and Upper Ordovician. British Ordovician divided into six systems, from the bottom were: ① Tremadocian system (Tremadoc Series), ② Allen Rummenigge system (ArenigSeries), ③ Lanwei En system (Llanvirn Series), ④ Portland on behalf of the Los Commission (Llandeilo Series), ⑤ Kara Road grams Commission (Caradoc Series), and ⑥ Ashe extremely Seoul Commission (Ashgill Series). Currently most of the Ordovician world countries have access to one-third, but not very consistent boundaries. Such as Sweden, Norway, the former Soviet Union, China, the United States and Australia, on the Ordovician top and bottom boundaries each with its own planning method (Table 1 China and other countries (or regions) of the Ordovician comparative summary table) . On the issue of reunification, there are different opinions in China. By two-thirds, rather Tremadocian systems, systems and Lanwei En Nigel Allen conventional strata under the EC; quite Llandeilo Road grams systems and karaoke system in the lower strata of the system; Carla Road grams traditional upper and Ashe system formation is extremely Seoul on system. By two points, namely, Llandeilo strata above the bottom boundary of the system is the system, following the formation of the next Commission, subject to the Yangtze platform division, established a small shell phase dominated phases. British Ordovician imprecise boundaries of the system, long used as a contrast to the international standards is a big weakness. British Ordovician stratified using a standard pen with a stone, and most parts of the world shelly development phase, so comparison is difficult to make the boundaries between the various systems to move up or down frequently. Recent British geologist D. Whittington et al (1984), after careful research, trying to define the bottom boundary of each system to complement its deficiencies. If the lower boundary Tremadocian to the bottom boundary of the system of social sector grid graptolites (Dictyonema flabelliforme sociale) subzone prevail. Nigel Allen bottom boundary of the bottom boundary of the system for the following song graptolites (Did-ymo □ raptus deflexus) subzone prevail.兰维恩 to the bottom boundary of the system of two points for pen Stone (Didymo □ raplus bifidus), whichever is the lower boundary zone. As Britain's D. 'bifidus' and D.bifidus North America is different, it was suggested that a straight narrow pen Stone (D.artus) bring alternative. Llandeilo to the bottom boundary of the system's sleek pen carved stone (Glypto □ raptus teretiusculus) with the lower boundary of the subject. Kara Road grams conventional thin wire to the bottom boundary of the past graptolites (Nema □ raptus □ racilis), whichever is the lower boundary zone, it seems not accurate enough, the need to continue to study. Ashe extremely Seoul conventional bottom boundary lies between Pleuro □ raptus linearis or conodonts Amorpho □ nathus superbus rock band with a pen. Recent British scholar in the three systems is divided into a number of bands: Czech and Slovak paleontologists think that the British system is actually the order. China long the British system as Ordovician order to use. Ordovician top and bottom boundaries are inconsistent. In the UK the original to the bottom boundary Glyp-to □ raptus persculptus band of Ordovician boundary, 1985 International Union has agreed to the bottom boundary Parakido □ raptus acuminatus with top industry for its geology, China and some other countries scientists there are different opinions. On the bottom boundary of the Ordovician, the world's most countries in the bottom boundary of the system Tremadocian prevail, only the UK tend to Allen Rummenigge bottom boundary of the system at the end of the Ordovician boundary (Table 1 China and other countries (or regions ) Ordovician comparative summary table). Chinese Ordovician sedimentary widely distributed, including the north, northeast, south and west. Deposition basically can be divided into two types: ① activity type deposition, such as the Tianshan, Larix trough area, Qilian slot area and southeast trough zones; ② stable type deposition, such as China and North Korea to Taiwan, the Yangtze platform and the Tarim places such as Taiwan. In addition, there is a transition between the two types of areas, such as the southern area. Rocks in the slot area has flysch clastic rocks, chert, volcanic rock, shale, and a small amount of carbonate rocks, a large general thickness, some areas may be