中国地质大学（武汉）冯庆来团队最新的研究，报道了华南埃迪卡拉纪-寒武纪（ca.551-523Ma）海绵的时空演化及其对海洋氧合的模拟贡献。2025年1月9日，《中国科学：地球科学》发表了这一成果。

海绵的起源和进化引起了人们的兴趣，不仅因为它们是最基础的后生动物之一，还因为它们在海洋中扮演着重要的生态工程师的角色。前人研究表明，在寒武纪第二世，海绵类群迅速多样化，但是Terreneuvian海绵化石明显稀少且证据不足。在世界范围内，特别是华南地区，越来越多的来自埃迪卡拉纪-寒武纪过渡型碳酸盐/燧石中的海绵骨针被报道，因此需要更新研究。人们普遍认为，海洋氧化作用在生物进化中起着关键作用，但它与海绵的关系尚不清楚，使得人们陷入了“先有鸡还是先有蛋”的困境。

本文对华南地区5个E-C剖面的海绵骨针分布进行了总结述，以探讨硅质海绵的早期演化模式。根据目前的地层对比证据，单轴骨针最早出现于晚埃迪卡拉世的陆架内盆地-斜坡区，有可能扩展到寒武纪晚期的陆架和深水盆地中。在这些剖面中，单轴骨针的丰度、大小和多样性向上增加，其次出现二轴骨针、三轴骨针和多轴骨针。尽管海绵化石的亲缘关系尚不确定，但考虑到最早的骨针组合完全由单轴骨针组成，它们通常形成与现代寻常海绵动物相当的束状结构，硅质六射海绵的进化可能晚于硅质寻常海绵动物。

贵州四方井剖面和湖南燕子桥剖面的地球化学新资料表明，海绵的外观通常对应于缺氧环境。此外，研究人员应用最近提出的生物泵/氧/磷（BPOP）模型，来追踪海洋氧浓度随海绵辐射的演变。结果表明，海绵对深海氧化的贡献是有限的。

附：英文原文

Title: Spatiotemporal evolution of Ediacaran-Cambrian (ca. 551–523Ma)sponges in South China and their simulated contributions to marine oxygenation

Author: Yan YE, Lei ZHANG, Can CHEN, Shan CHANG, Yuhao YI, Qinglai FENG

Issue&Volume: 2025/01/09

Abstract: The origin and evolution of sponges have attracted interest, not only because they are among the most basal metazoans, but also because they act as important ecological engineers in the ocean. Previous research suggested that sponge groups diversified quickly during the Cambrian Series 2, while Terreneuvian sponge fossils are conspicuously rare and poorly substantiated. Yet, an increasing number of sponge spicules have been reported from the Ediacaran-Cambrian (E-C, ca. 551–523Ma) transitional carbonates/cherts worldwide, particularly in South China, which calls for updated discussions. Ocean oxygenation has been widely proposed to play a critical role in organismal evolution, but its relationship with sponges is unclear and falls into a “chicken-egg” dilemma. In this study, we summarize reported sponge spicule distributions from five E-C sections in South China to investigate the early evolutionary pattern of siliceous sponges. According to current stratigraphic correlation, monaxons first appear in the late Ediacaran in the intrashelf basin-slope area, and then potentially expand to the continental shelf and deep basin in the lower Cambrian. In these sections, the abundance, size, and diversity of monaxons increase upwards, followed by the appearance of diaxons, triaxons and then polyactines. Despite the uncertain affinity of the sponge fossils, it is possible that siliceous hexactinellids evolved later than siliceous demosponges, given that the earliest spicule assemblages are exclusively composed of monaxons, which commonly form bundles comparable to modern demosponges. New geochemical data from the Sifangjing section, Guizhou Province and the Yanziqiao section, Hunan Province, South China show that the appearance of sponges usually corresponds to anoxic environment. In addition, we applied the recently proposed Biological Pump, Oxygen and Phosphorus (BPOP) model to trace the evolution of oceanic oxygen concentrations with the radiation of sponges. The results indicate that the possible contribution of sponges to oxygenation of the deep ocean was limited.

DOI: 10.1007/s11430-024-1468-9

Source: https://www.sciengine.com/SCES/doi/10.1007/s11430-024-1468-9