Distinctive microfossil supports early Paleoproterozoic rise in complex cellular organisation
Distinctive microfossil supports early Paleoproterozoic rise in complex cellular organisation
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DOI：
10.1111/gbi.12576
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发表时间：
2023-10-06
期刊：
影响因子：
3.7
通讯作者：
Van Kranendonk，Martin J.
中科院分区：
文献类型：
--
作者：
Barlow，Erica V.;House，Christopher H.;Van Kranendonk，Martin J.
大约24亿年前的大氧化事件（GOE）使地球表面环境的化学成分发生了根本性的变化。然而，这些变化对生物圈的影响是未知的，因为世界范围内缺乏这一时期保存完好的化石。在这里，我们研究了在澳大利亚西部约2.4 Ga的Turee Creek群中，在燧石中被过矿化的保存异常完好的大球形聚集体（SA）微化石。野外和岩石学观察、拉曼光谱测绘和原位碳同位素分析揭示了这种不寻常形式的形态、栖息地、繁殖和代谢，其独特的SA形态在化石记录中没有已知的对应物。与GOE之前的微化石比较分析表明，大型SA微化石代表了细胞组织的一个步骤。与现存微生物的形态比较表明，sa与合生藻类比球藻更相似，强调了这种微化石形式的复杂性。这里引人注目的保存为了解生物圈提供了一个独特的窗口，揭示了与GOE相吻合的生命复杂性的增加。
The great oxidation event (GOE), ~2.4 billion years ago, caused fundamental changes to the chemistry of Earth's surface environments. However, the effect of these changes on the biosphere is unknown, due to a worldwide lack of well‐preserved fossils from this time. Here, we investigate exceptionally preserved, large spherical aggregate (SA) microfossils permineralised in chert from the c. 2.4 Ga Turee Creek Group in Western Australia. Field and petrographic observations, Raman spectroscopic mapping, and in situ carbon isotopic analyses uncover insights into the morphology, habitat, reproduction and metabolism of this unusual form, whose distinctive, SA morphology has no known counterpart in the fossil record. Comparative analysis with microfossils from before the GOE reveals the large SA microfossils represent a step‐up in cellular organisation. Morphological comparison to extant micro‐organisms indicates the SAs have more in common with coenobial algae than coccoidal bacteria, emphasising the complexity of this microfossil form. The remarkable preservation here provides a unique window into the biosphere, revealing an increase in the complexity of life coinciding with the GOE.