近日，中国地质大学（武汉）纵瑞文团队报道，志留纪最底层黑色页岩中发现保存完好的新动物群，提供了对晚奥陶世大规模灭绝后深水生态系统恢复的见解。2025年1月2日出版的《地质学》发表了这项成果。

本研究在中国Rhuddanian阶（下志留统）黑色笔石页岩中发现了一种新的特异保存的动物群——黄石动物群。动物群主要由海绵动物组成，另外还有头足类、节肢动物和一些神秘的碳膜化石。尽管与其他浅水相的早古生代特别保存的生物区系相比，该动物区系的多样性较低，但它为第一次大灭绝后深水生态系统的生物组合提供了新的数据。

这种以海绵为主的动物群不仅加深了人们对奥陶纪海绵时空分布的认识，华南志留纪的过渡期也暗示了，广泛分布的志留纪下部黑色页岩的沉积环境并非完全缺氧，表明海底存在间歇性氧化时期。

据了解，在晚奥陶世的两次大灭绝之后，海平面的持续上升导致世界各地深水区形成了缺氧黑色页岩沉积物。这些沉积物通常只含有笔石化石组合。研究人员在华南奥陶纪-志留纪过渡期的笔石页岩中发现了海绵为主的生物组合，增加了这些地层内已知的生物多样性。

附：英文原文

Title: A new exceptionally preserved fauna from a lowest Silurian black shale: Insights into the recovery of deep-water ecosystems after the Late Ordovician mass extinction

Author: Ruiwen Zong, Yilong Liu, Qi Liu, Juan Ma, Shibo Liu

Issue&Volume: 2025-01-02

Abstract: After two pulses of mass extinction during the Late Ordovician, a continuous rise in sea level led to the formation of anoxic black shale deposits in deep-water areas in various regions of the world. These deposits usually contain only graptolite fossil assemblages. The discovery of sponge-dominated assemblages in graptolitic shale of the OrdovicianSilurian transition in South China has increased the known biodiversity within these strata. Here we document a new exceptionally preserved fauna, the Huangshi Fauna, in Rhuddanian (lower Silurian) black graptolitic shale of South China. The fauna is composed primarily of sponges, with additional representatives including cephalopods, arthropods, and some enigmatic carbon film fossils. Although this fauna exhibits less diversity compared to other early Paleozoic exceptionally preserved biotas in shallow-water facies, it provides new data on the biological assemblage of deep-water ecosystems after the first mass extinction. This sponge-dominated fauna not only enhances insight into the spatial and temporal distribution of sponges during the OrdovicianSilurian transition in South China but also implies that the depositional environment of the widespread lowest Silurian black shale was not entirely anoxic, indicating periods of intermittent oxygenation at the seafloor.

DOI: 10.1130/G53042.1

Source: https://pubs.geoscienceworld.org/gsa/geology/article-abstract/doi/10.1130/G53042.1/651252/A-new-exceptionally-preserved-fauna-from-a-lowestredirectedFrom=fulltext