论文部分内容阅读
6500万年前,一次巨大的灭绝危机袭击了地球生物界;在地层层序上,这正好是发生于白垩系与第三系的交界处。在这次危机中,海洋爬行动物、会飞的爬行类、恐龙,以及菊石类、箭石等都绝迹了;灾难性的灭绝也发生于微型浮游动、植物之中;钙质浮游有孔虫和钙质微型浮游植物也几乎被一扫而空。Russell指出,在灭绝事件的整个过程中,大约50％的生物属或估计达75％的生物种从地球上消失了。 这样一次巨大的事件在地球演化历史上是极其引人注目的。许多科学家对导致该事件的原因进行了探讨,并且提出了大量的假说。由于人们不断的努力,
65 million years ago, a massive crisis of extinction hit the Earth’s biological kingdom; in the sequence of stratigraphy, this happened at the junction of the Cretaceous and Tertiary. In this crisis, reptiles of the sea, flying reptiles, dinosaurs, and ammonites, arrow stones, etc. are extinct; catastrophic extinction also occurs in micro-floating plains, plants; calcareous planktonic holes Insects and calcium micro-phytoplankton are almost swept away. Russell pointed out that about 50% of the genus or about 75% of the estimated species disappeared from the planet during the entire extinction event. Such a huge event has drawn the most attention in the history of the Earth’s evolution. Many scientists have explored the causes of the incident and have come up with a large number of hypotheses. As people continue to work hard,