Primary gypsum represents an excellent paleobiological archive due to its early and fast growth, favoring the preservation of delicate biomineralized structures. The Mediterranean region is renowned for evaporite deposits that formed during the Messinian salinity crisis (MSC), an event that supposedly annihilated most of the marine biota. However, the Messinian evaporites have been scarcely studied for their fossil content. Abundant nano-sized planktic diatoms and associated organic matter are observed for the first time in bottom-grown gypsum crystals that formed during the early stage of the MSC in different marginal basins of the western Mediterranean. This discovery increases our knowledge of the Messinian biota and reveals that nano-sized planktic diatoms played a prominent role in carbon and silicon export during gypsum deposition. The co-occurrence of these diatoms with larger diatoms, possibly associated with a deep chlorophyll maximum, suggests that Messinian gypsum formed in stratified and relatively deep basins (far below the photic zone), typified by marine conditions in the upper water column. The nano-sized planktic diatoms may have taken advantage of the hydrological reconfigurations experienced by the Mediterranean since the onset of the MSC. This study confirms that primary gypsum represents a promising archive of information for elucidating the marine biotic response to an ancient environmental crisis.

中文翻译：

---

微小、玻璃状且快速被困：墨西拿（晚中新世）石膏中的纳米级浮游硅藻

由于其早期和快速的生长，原生石膏代表了极好的古生物学档案，有利于保存精致的生物矿化结构。地中海地区以在墨西拿盐度危机 (MSC) 期间形成的蒸发岩沉积物而闻名，该事件据称消灭了大部分海洋生物群。然而，几乎没有研究墨西拿蒸发岩的化石含量。在地中海西部不同边缘盆地的MSC早期形成的底部生长的石膏晶体中首次观察到丰富的纳米级浮游硅藻和相关有机物。这一发现增加了我们对墨西拿生物群的了解，并揭示了纳米尺寸的浮游硅藻在石膏沉积过程中的碳和硅输出中发挥了重要作用。这些硅藻与较大的硅藻同时出现，可能与叶绿素最大程度有关，这表明墨西拿石膏形成于分层和相对较深的盆地（远低于光区），以上部水柱的海洋条件为代表。纳米尺寸的浮游硅藻可能利用了地中海自 MSC 出现以来经历的水文重构。这项研究证实，原生石膏代表了一个有希望的信息档案，用于阐明海洋生物对古代环境危机的反应。纳米尺寸的浮游硅藻可能利用了地中海自 MSC 出现以来经历的水文重构。这项研究证实，原生石膏代表了一个有希望的信息档案，用于阐明海洋生物对古代环境危机的反应。纳米尺寸的浮游硅藻可能利用了地中海自 MSC 出现以来经历的水文重构。这项研究证实，原生石膏代表了一个有希望的信息档案，用于阐明海洋生物对古代环境危机的反应。