二叠纪末生物礁生态系的绝灭是怎样发生的?一蹴而就,还是分几步发生的?对贵州紫云长兴期生物礁顶二个二叠纪-三叠纪界线地层(PTB)剖面的研究表明:礁生态系的绝灭是分二幕进行的.第一幕是钙质海绵、蜓等狭适性生物的完全绝灭,发生在Clarkina yini带内.此后的生物群是由小腹足类、一些介形虫以及某些小型钻孔生物组成的简单生物群,或仅由藻席组成.在Hindeodus parvus带开始的时候,生物礁顶部变成缺氧环境.原来以小腹足类或藻席为主的简单生物群发生绝灭(此为第二个绝灭幕),代之以小球状的疑源类微生物为主的特化生物群.以后在环境变成有氧时,这个特化生物群又被微小腹足类为主的简单生物群取代,代表海洋生态系的初步复苏.此后随着海洋环境的进一步改善,这个生物群被正常大小的菊石、双壳类、腹足类组成的较为多样性的生物群取代,代表海洋生态系的进一步恢复.谈陆寨剖面是目前所知的唯一的生物礁发育到二叠纪最晚期并遭受大绝灭事件影响的剖面.与煤山金钉子剖面和意大利Dolomites的Tesero剖面的对比表明,非礁生态系有一个和礁生态系相同的第一幕绝灭事件.发生缺氧事件的非礁生态系,有一个和礁生态系相似的第二幕绝灭事件. How did the extinction of the Permian end reef ecosystem take place in a single step, or did it occur in several steps? The Permian Triassic Boundary Stratigraphy (PTB) section of the Changxing Period reef cretaceous in Guizhou Province The study shows that the extinction of the reef ecosystem is divided into two episodes: the first is the complete extinction of the slender creatures such as calcareous sponge and dragonfly in the Clarkina yini zone, Class, some ostracods, and some small bore creatures, or simply algae mat composition. At the beginning of the Hindeodus parvus band, the top of the reefs turned into an anoxic environment. Originally the small belly or algae The extinction of a simple biotic assemblage (the second extinction curtain) replaced by a special globular biota of doubtful microorganisms, The biota was replaced by a simple biota based mainly on gastropods, representing the initial recovery of marine ecosystems. Since then, as the marine environment has further improved, this biota has been replaced by normal-sized ammonites, bivalves, A more diverse group of biota, replaced by representatives of marine ecology The further restoration of the Luzhai section is by far the only known section of the reef that developed to the latest of the Permian and suffered a major extinction event.The comparison with the Meishan gold nail section and the Tesero section of the Dolomites in Italy , The non-reef ecosystem has the same first extinction event as the reef ecosystem.The non-reef ecosystem where there is anoxia event has a second extinction event similar to reef ecosystem.