The driver of the Early–Middle Triassic biotic recovery on land following the end-Permian crisis is puzzling. Here, we show the biotic recovery was gradual and spanned up to 8 Myr after the end-Permian mass extinction, based on continuous, well-dated sections over large areas in the northeastern Ordos Basin, North China. Initial recovery began in the Olenekian, marked by the disappearance of microbially induced sedimentary structures and reappearance of bioturbation, and continued in the Anisian, with a bloom of plants and tetrapods and intense bioturbation. Sedimentary environments changed from Induan braided-eolian conditions to Olenekian–Anisian shallow lacustrine and meandering river systems, marking an overall deepening lacustrine system. Carbonate δ¹³C and geochemical proxies of weathering intensity, salinity and clayiness reveal an overall warm and semi-humid paleoclimate in the Olenekian–Anisian. This improved stable paleoenvironment of warm and semi-humid conditions likely contributed to the biotic recovery following the Permian-Triassic hyperthermal-related crisis.

在二叠纪末期危机之后，早中期三叠世陆地生物恢复的驱动力令人费解。在这里，我们根据华北鄂尔多斯盆地东北部大面积连续的、年代久远的剖面显示，在二叠纪末大规模灭绝后，生物恢复是渐进的，跨越了长达 8 Myr。最初的复苏始于奥列内克纪，其标志是微生物诱导的沉积结构消失和重新出现生物扰动，并在阿尼西亚继续，植物和四足动物大量繁殖，生物扰动强烈。沉积环境从印都辫状-风成条件转变为奥列内克阶-阿尼西阶浅湖和蜿蜒河流系统，标志着湖泊系统整体深化。碳酸盐 δ ¹³C 和风化强度、盐度和粘土性的地球化学指标揭示了 Olenekian-Anisian 的整体温暖和半湿润的古气候。这种改善的温暖和半湿润条件的稳定古环境可能有助于二叠纪-三叠纪与高温相关的危机之后的生物恢复。