Life Sciences Department, Natural History Museum, London, UK
School of Earth and Environment, University of Leeds, Leeds, UK.
Proc Biol Sci. 2018 Nov 14;285(1891):20182004. doi: 10.1098/rspb.2018.2004.
Microorganisms are the chief primary producers within present-day deep-sea hydrothermal vent ecosystems, and play a fundamental role in shaping the ecology of these environments. However, very little is known about the microbes that occurred within, and structured, ancient vent communities. The evolutionary history, diversity and the nature of interactions between ancient vent microorganisms and hydrothermal vent animals are largely undetermined. The oldest known hydrothermal vent community that includes metazoans is preserved within the Ordovician to early Silurian Yaman Kasy massive sulfide deposit, Ural Mountains, Russia. This deposit contains two types of tube fossil attributed to annelid worms. A re-examination of these fossils using a range of microscopy, chemical analysis and nano-tomography techniques reveals the preservation of filamentous microorganisms intimately associated with the tubes. The microfossils bear a strong resemblance to modern hydrothermal vent microbial filaments, including those preserved within the mineralized tubes of the extant vent polychaete genus The Yaman Kasy fossil filaments represent the oldest animal-microbial associations preserved within an ancient hydrothermal vent environment. They allude to a diverse microbial community, and also demonstrate that remarkable fine-scale microbial preservation can also be observed in ancient vent deposits, suggesting the possible existence of similar exceptionally preserved microfossils in even older vent environments.
微生物是现今深海热液喷口生态系统中的主要初级生产者，对这些环境的生态结构起着至关重要的作用。然而，对于存在于古代喷口群落并塑造其结构的微生物，我们知之甚少。古代喷口微生物与热液喷口动物之间的进化历史、多样性以及相互作用的性质在很大程度上尚未确定。已知最古老的包含后生动物的热液喷口群落保存在俄罗斯乌拉尔山脉的奥陶纪至早志留世的亚曼卡西块状硫化物矿床中。该矿床包含两种管化石，归因于环节动物蠕虫。使用一系列显微镜、化学分析和纳米断层扫描技术对这些化石进行重新检查，揭示了与管密切相关的丝状微生物的保存。这些微化石与现代热液喷口微生物丝状体非常相似，包括保存在现存喷口多毛类属的矿化管内的那些丝状体。亚曼卡西化石丝状体代表了在古代热液喷口环境中保存的最古老的动物-微生物共生体。它们暗示了一个多样化的微生物群落的存在，也表明在古代喷口沉积物中也可以观察到显著的精细尺度微生物保存，这表明在甚至更古老的喷口环境中可能存在类似的保存异常完好的微化石。
