Benton M J, Tverdokhlebov V P, Surkov M V
Department of Earth Sciences, University of Bristol, Bristol BS8 1RJ, UK.
Nature. 2004 Nov 4;432(7013):97-100. doi: 10.1038/nature02950.
The mass extinction at the Permian-Triassic boundary, 251 million years (Myr) ago, is accepted as the most profound loss of life on record. Global data compilations indicate a loss of 50% of families or more, both in the sea and on land, and these figures scale to a loss of 80-96% of species, based on rarefaction analyses. This level of loss is confirmed by local and regional-scale studies of marine sections, but the terrestrial record has been harder to analyse in such close detail. Here we document the nature of the event in Russia in a comprehensive survey of 675 specimens of amphibians and reptiles from 289 localities spanning 13 successive geological time zones in the South Urals basin. These changes in diversity and turnover cannot be explained simply by sampling effects. There was a profound loss of genera and families, and simplification of ecosystems, with the loss of small fish-eaters and insect-eaters, medium and large herbivores and large carnivores. Faunal dynamics also changed, from high rates of turnover through the Late Permian period to greater stability at low diversity through the Early Triassic period. Even after 15 Myr of ecosystem rebuilding, some guilds were apparently still absent-small fish-eaters, small insect-eaters, large herbivores and top carnivores.
2.51亿年前二叠纪-三叠纪边界的大灭绝被公认为有记录以来最严重的生命损失。全球数据汇编表明，海洋和陆地的科损失了50%或更多，根据稀疏分析，这些数字相当于物种损失了80%-96%。海洋剖面的局部和区域尺度研究证实了这种损失程度，但陆地记录更难进行如此详细的分析。在这里，我们通过对南乌拉尔盆地13个连续地质时区的289个地点的675个两栖动物和爬行动物标本进行全面调查，记录了俄罗斯该事件的性质。多样性和更替率的这些变化不能简单地用采样效应来解释。属和科大量减少，生态系统简化，小型食鱼动物和食虫动物、中型和大型食草动物以及大型食肉动物消失。动物群动态也发生了变化，从二叠纪晚期的高更替率到三叠纪早期低多样性时更高的稳定性。即使在生态系统重建1500万年之后，一些生态群落显然仍然缺失——小型食鱼动物、小型食虫动物、大型食草动物和顶级食肉动物。
