Early and Middle Triassic trends in diversity, evenness, and size of foraminifers on a carbonate platform in south China: Implications for tempo and mode of biotic recovery from the end-Permian mass extinction

Delayed biotic recovery from the end-Permian mass extinction has long been interpreted to result from environmental inhibition. Recently, evidence of more rapid recovery has begun to emerge, suggesting the role of environmental inhibition was previously overestimated. However, there have been few high-resolution taxonomic and ecological studies spanning the full Early and Middle Triassic recovery interval, leaving the precise pattern of recovery and underlying mechanisms poorly constrained. In this study, we document Early and Middle Triassic trends in taxonomic diversity, assemblage evenness, and size distribution of benthic foraminifers on an exceptionally-exposed carbonate platform in south China. We observe gradual increases in all metrics through Early Triassic and earliest Middle Triassic time, with stable values reached early in the Anisian. There is little support in our dataset for a substantial Early Triassic lag interval during the recovery of foraminifers or for a step...二叠纪末大灭绝（end-Permian mass extinction）后生物复苏延迟的现象，长期以来被归因于环境抑制作用。近年来，有关生物复苏速度快于此前预期的证据陆续浮现，这表明环境抑制的影响曾被过度高估。然而，目前鲜有覆盖完整早三叠世至中三叠世复苏时段的高分辨率分类学与生态学研究，使得学界对复苏的精确模式与潜在驱动机制的认知仍较为有限。本研究以中国南方一处出露条件极佳的碳酸盐台地（carbonate platform）为研究对象，记录了底栖有孔虫（benthic foraminifers）的分类多样性、群落均匀度以及体型分布在早-中三叠世的演化趋势。研究结果显示，早三叠世至中三叠世早期，上述所有指标均呈逐步上升趋势，并在安尼阶（Anisian）早期达到稳定水平。本数据集并不支持有孔虫复苏存在显著的早三叠世滞后阶段，亦不支持存在阶段性复苏模式