New record of organic-walled, morphologically distinct microfossils from the late Paleoproterozoic Changcheng Group in the Yanshan Range, North China
New record of organic-walled, morphologically distinct microfossils from the late Paleoproterozoic Changcheng Group in the Yanshan Range, North China
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DOI：
10.1016/j.precamres.2018.11.019
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发表时间：
2019-02
影响因子：
3.8
通讯作者：
Lanyun Miao;M. Moczydłowska;Shixing Zhu;Maoyan Zhu
中科院分区：
文献类型：
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作者：
Lanyun Miao;M. Moczydłowska;Shixing Zhu;Maoyan Zhu
Eukaryotic life has likely existed since the late Paleoproterozoic, yet little is known about its early diversity and phylogenetic relationships. Organic-walled microfossils (OWMs) with conspicuous morphology provide a unique material to investigate the deep evolution of eukaryotic and prokaryotic microbial clades. Here we report a diverse assemblage of OWMs from the lower Changcheng Group (c. 1673–1638 Ma, Changzhougou and Chuanlinggou formations) in the Yanshan Range, North China, which consists of 15 species, including 2 that are newly described. The fossil assemblage is dominated by spheromorphs with less numerous process-bearing vesicles, as are colonial and filamentous forms. Among these, 6 morphologically complex taxa (Dictyosphaera, 2 species ofGerminosphaera,Pterospermopsimorpha,Simia, andValeria) are identified as unambiguous unicellular eukaryotes. Four species (Cucumiforma,Navifusa,Schizofusaand largeLeiosphaeridia) with relatively simple morphology but having large size, thick wall, and some showing median-split excystment structures, are of probable eukaryotic affinity. However, various colonial microfossils could be either eukaryotes or prokaryotes. The new record of morphologically disparate OWMs represents one of the earliest occurrences of eukaryotes in both China and the world, and indicates that the eukaryotic life was already well established in the late Paleoproterozoic and was of moderate diversity, similar to that of the Mesoproterozoic.
