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二叠纪末集群绝灭(terminal Permian mass extinction)是显生宙最大规模的生物绝灭事件,一般认为这次事件是渐进的(gradual),持续了数百万年,表现复杂,具有多重性质,在这次事件中,陆地生态系统濒临崩溃;植被显示严峻的退化演替(regressive succes-sion)趋势;树木凋零,菌毒麇集成灾,导致全球性“缺煤事件”,那些在石炭纪时期十分繁盛的植物,大部分绝灭了,唯有裸子植物例外,它们进入二叠纪以后,迅速辐射扩散并完成了古一中植代过渡,成为植物群的主要成分,不过在这次事件的打击下,也只有少数续存于中生代.据Cleal统计全球二叠纪20个裸子植物科级分类中,仅2～3科穿过了二叠三叠纪(以下简称P-Tr)界线,也正是这些幸存者的后裔成为中生代植物群的主体.
The Permian mass extinction, the largest extinction event in the Phanerozoic, is generally considered to be a gradual, multi-million-year event with a complex and multi-faceted nature In this case, the terrestrial ecosystems were on the verge of collapse; the vegetation showed a severe trend of regressive succes- sion; the decay of trees and the integration of poisonous bacteria and poisoning led to the global “coal-lacking event.” Those in the Carboniferous During the period most of the plants flourished, most of which were extinct. Except for the gymnosperms, after their arrival in the Permian, they quickly spread the radiation and completed the transition from Palaeo-Mesozoic to Mesozoic and became the main components of the flora. However, during this event Only a few survived in the Mesozoic.According to Cleal statistics, in the Permian 20 families of gymnosperms in the Permian, only 2 to 3 families crossed the Permian Triassic (hereinafter referred to as P-Tr) It is also the descendants of these survivors that have become the main body of Mesozoic flora.