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In a well-preserved sequence in east Greenland, the decline of animals is concentrated in a period 10,000 to 60,000 years long, with plants taking an additional several hundred thousand years to show the full impact of the event.
is that there were two major extinction pulses 9.4 million years apart, separated by a period of extinctions well above the background level, and that the final extinction killed off only about 80% of marine species alive at that time while the other losses occurred during the first pulse or the interval between pulses.
In this preliminary extinction, which greatly reduced disparity, or the range of different ecological guilds, environmental factors were apparently responsible.
Eight or nine insect orders became extinct and ten more were greatly reduced in diversity.These cyclical flora shifts occurred a few times over the course of the extinction period and afterwards.These fluctuations of the dominant flora between woody and herbaceous taxa indicate chronic environmental stress resulting in a loss of most large woodland plant species.U–Pb zircon dates from five volcanic ash beds from the Global Stratotype Section and Point for the Permian–Triassic boundary at Meishan, China, establish a high-resolution age model for the extinction – allowing exploration of the links between global environmental perturbation, carbon cycle disruption, mass extinction, and recovery at millennial timescales.The extinction occurred between 251.941 ± 0.037 and 251.880 ± 0.031 Ma ago, a duration of 60 ± 48 ka.