During the Mississippian period, metazoan reefs and other marine faunas gradually recovered from the Late Devonian mass extinctions and reached a peak in the late Visean (~334–332 Ma). Faunal diversity started to decline from the latest Visean (~332–330 Ma) through Serpukhovian (~330–323 Ma), with significant genera/species losses and ecosystem reconstruction. This Middle-Late Mississippian biodiversity crisis (M-LMBC) was thought to have been caused by global cooling associated with the late Paleozoic Ice Age (LPIA), but existing sedimentological and temperature proxy data suggest that the global cooling event—that marks the onset of the main glaciation phase of LPIA—happened either ~4 Myr before or ~ 1–5 Myr after the initial biodiversity decline at ~332 Ma. Here, we report oxygen isotope data of diagenetically screened, well-preserved brachiopod calcite (δ¹⁸O_calcite) from late Visean-Serpukhovian (or Middle-Late Mississippian; ~334–323 Ma) strata in South China where biodiversity data are well documented. The δ¹⁸O_calcite data reveal a ~ 2.0‰ positive shift from −4.6 ± 0.2‰ to −2.7 ± 0.5‰ with an estimated ~4.7–5.5 °C drop in sea surface temperature (SST) during ~332.5–331.5 Ma in the late Visean. This cooling event coincides with fast decline of metazoan reef abundance, followed by decrease of benthic faunal diversity. The δ¹⁸O_calcite data, in combination with calibrated sedimentological and biodiversity data, demonstrate the coupling between late Visean (~332 Ma) onset of the main glaciation phase of the LPIA and initiation of the M-LMBC.

在密西西比时期，后生动物礁和其他海洋动物群逐渐从晚泥盆世大规模灭绝中恢复过来，并在晚 Visean (~334-332 Ma) 达到顶峰。从最近的 Visean（~332-330 Ma）到 Serpukhovian（~330-323 Ma），动物多样性开始下降，具有显着的属/物种损失和生态系统重建。这场中晚期密西西比纪生物多样性危机 (M-LMBC) 被认为是由与晚古生代冰河时代 (LPIA) 相关的全球变冷引起的，但现有的沉积学和温度代理数据表明，标志着全球变冷事件的开始LPIA 的主要冰川期——发生在约 332 Ma 的初始生物多样性下降之前约 4 Myr 或约 1-5 Myr 之后。在这里，我们报告了成岩筛选的氧同位素数据，¹⁸ O_方解石）来自华南 Visean-Serpukhovian 晚期（或密西西比中晚期；~334-323 Ma）地层，其中生物多样性数据有据可查。δ ¹⁸ O_方解石数据显示从 -4.6 ± 0.2‰ 到 -2.7 ± 0.5‰ 的约 2.0‰ 正偏移，估计海表温度 (SST) 在约 332.5-331.5 Ma 期间下降约 4.7-5.5 °C已故的维森。这一降温事件恰逢后生动物礁丰度迅速下降，随后底栖动物多样性下降。δ ¹⁸ O_方解石数据与校准的沉积学和生物多样性数据相结合，证明了 LPIA 主要冰川期的晚 Visean（~332 Ma）开始与 M-LMBC 开始之间的耦合。