animal > Dias big Annihilation incident
Contents
No. 1
  The mass extinction is abrupt climate change, the desert expanded, volcanic eruptions and a series of reasons.
  Meteorite impact
  Tours Scientists believe the meteorite or asteroid colliding with Earth led to the end-Permian mass extinction. If this impact to a certain extent, it will have an devastating in the global shock waves, caused by climate change and biological death. Recently collected some evidence raises the importance of this view. However, most biological scientists believe that this extinction is caused by natural variations in the Earth's.
  Climate change
  Some scientists believe that climate change is the main reason for the formation of this disaster. Because the formation of Permian rocks show that the climate was cooling in some areas, the formation of the polar ice caps on Earth. These huge ice sheets of white sunlight back into space launch, will further reduce global warming, land and sea creatures so difficult to adapt. If we add the plane down and volcanic eruptions Shanghai, which will become a disaster.
  Changes in atmospheric composition
  Some biologists believe that an active lifestyle more active animals such as mammals like the single bow animals need more oxygen than other animals, they may be due to changes in atmospheric composition extinction. Because the temperature of the lower Permian sea level will lead to the decline. The vast sea-bed area will be left exposed coal, releasing carbon dioxide into the atmosphere, the oxygen content in the atmosphere will be reduced.
  Volcanic activity
  Volcanic eruptions and volcanic gases back to a lot of dust emitted into the atmosphere. Volcanic mountain group will not only suffocate animals may also be obscured the sun, global temperatures decreased. Therefore, the volcanic activity may also be the end-Permian extinction event is one of the reasons. Siberia, once discovered that the violent eruption of the volcano ejected material.
  The ravages of the desert
  Permian collision of continental blocks to form a large contiguous Pangaea. Rain and fog from the sea can no longer probe into the interior. So some areas of the Permian is getting dry and hot, leading to increasingly wide range of desert, arid environment of the animals can not adapt became extinct.
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概述
  距今约2.5亿年前的二叠纪末期,发生了有史以来最严重的大灭绝事件,估计地球上有96%的物种灭绝,其中90%的海洋生物和70%的陆地脊椎动物灭绝。三叶虫、海蝎以及重要珊瑚类群全部消失。陆栖的单弓类群动物和许多爬行类群也灭绝了。 这次大灭绝使得占领海洋近3亿年的主要生物从此衰败并消失,让位于新生物种类, 生态系统也获得了一次最彻底的更新,为恐龙类等爬行类动物的进化铺平了道路。 科学界普遍认为,这一大灭绝是地球历史从古生代向中生代转折的里程碑。其他各次大灭绝所引起的海洋生物种类的下降幅度都不及其1/6, 也没有使生物演化进程产生如此重大的转折。
  这次大灭绝是由气候突变、沙漠范围扩大、火山爆发等一系列原因造成。科学家认为,在二叠纪曾经发生海平面下降和大陆漂移,这造成了最严重的物种大灭绝。那时,所有的大陆聚集成了一个联合的古陆,富饶的海岸线急剧减少,大陆架也缩小了,生态系统受到了严重的破坏,很多物种的灭绝是因为失去了生存空间。更严重的是,当浅层的大陆架暴露出来后,原先埋藏在海底的有机质被氧化,这个过程消耗了氧气,释放也二氧化碳。大气中氧的含量有可能减少了这对生活在陆地上的动物非常不利。随着气温升高,海平面上升,又使许多陆地生物遭到灭顶之灾,海洋里也成了缺氧地带。地层中大量沉积的富含有机质的页岩是这场灾难的证明。
Analysis
  Meteorite impact
  Some scientists believe that meteorites or asteroids colliding with Earth led to the end-Permian mass extinction. If this impact to a certain extent, it will have an devastating in the global shock waves, caused by climate change and biological death. Recently collected some evidence raises the importance of this view. However, most biological scientists believe that this extinction is caused by natural variations in the Earth's.
  Climate change
  Some scientists believe that climate change is the main reason for causing this disaster. Because the formation of Permian rocks show that the climate was cooling in some areas, the formation of the polar ice caps on Earth. These huge white ice to reflect sunlight back into space, will further reduce the global temperature, so that land and sea creatures is difficult to adapt. If we add the plane down and volcanic eruptions Shanghai, this will become a disaster.
  Changes in atmospheric composition
  Some biologists believe that it is more active, aggressive animals such as mammals, similar to the single arch animals need more oxygen than other animals, they may be due to changes in atmospheric composition extinction. Because the temperature of the lower Permian sea level will lead to the decline. The vast sea-bed area will be left exposed coal, releasing carbon dioxide into the atmosphere, the oxygen content in the atmosphere will be reduced.
  Volcanic activity
  Volcanic eruptions emit large quantities of gases and volcanic dust into the atmosphere. Ash, dust will not only suffocate animals may also be obscured sunlight, reducing the global temperature. Therefore, the volcanic activity may also be the end-Permian extinction event is one of the reasons. Siberia, once discovered that the violent eruption of the volcano ejected material.
  The ravages of the desert
  Permian collision of continental blocks to form a large contiguous Pangaea. Rain and fog from the sea can no longer further inland. So some areas of the Permian is getting dry, hot, resulting in increasingly wide range of desert, arid environment of plants and animals can not adapt became extinct.
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Extinct species
  Trilobite arthropods only a few representatives of gastropods and bivalves have a new development. Permian, rugose corals, horizontal plate corals, bamboo pole class, all trilobite extinction; brachiopods greatly reduced, the few remaining categories.
  Flourished in the early Paleozoic trilobites, rugose corals, horizontal plate corals, dragonflies, and all classes extinction foraminifera and crinoids, brachiopods, ammonoids, echinoderms, bryozoans, also suffered a serious blow.
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New interpretation of mass extinction
  In early 2008, the Chinese Academy of Sciences, Nanjing Paleontology Cao young group and other researchers on the south wing of Xinjiang and the peach garden of Longkou the organic carbon isotope profile of the end of the Permian there found two negative anomalies, which will terrestrial ecosystems collapse divided into two acts, and proposed terrestrial ecosystems to reflect the mass extinctions may be earlier than the new view of marine ecosystems, in order to investigate the end-Permian extinction event mechanism provides a new interpretation. EPSL internationally renowned publication has been published in the online edition of the results.
  The study combined land and sea phase formation biomarkers, chain fungi / algae and other debris and evidence of magnetic susceptibility contrast, the establishment of continental strata in Xinjiang region in China marine strata in Meishan Permian - Triassic the evolution of the carbon isotope contrast between the precise, that before the end-Permian extinction event occurred the same sea organic carbon isotope reduce incident was due to lower sea levels caused by stagnation of hydrogen sulfide-rich, oxygen-deficient the existence of the marine environment and its atmosphere and terrestrial ecosystems of the deep. The sea, continental ecosystems abnormal sensitivity to environmental differences, making the end-Permian terrestrial ecosystems, reflecting earlier in the marine ecosystem, which supported the 2005 core drilling through the samples of Meishan section, Zhejiang Institute concluded , that is rich in marine photosynthetic water environment of hydrogen sulfide as the end-Permian extinction the dominant factor. This conclusion is representative for the South African Karoo Basin Triassic vertebrate Lystrosaurus the early appearance of the Permian - Triassic, the emergence of abnormal pollen morphology and fossil pollen and Mixed transition and fossil ostracods the face of a sharp early change provides a reasonable explanation. The study also proved the southern wing of the profile Dalongkou continental strata, represented a more complete development of the Permian - Triassic sedimentary transition period, more than Australia and Antarctica's continental stratigraphic section.
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