Abundant, well‐preserved specimens of spheroidal organic‐walled microfossil Yurtusia uniformis are reported from the basal Cambrian Yanjiahe Formation in the Changyang area of Hubei Province, South China. Thin and hollow processes extend between the double walls of the vesicle. The single to multiple internal bodies within the vesicle cavity are observed in the genus for the first time, representing reproductive structures (dividing daughter cells). A small circular perforation may occur on the vesicle wall to release the internal bodies. Morphological analyses of specimens preserved at various life stages reveal that processes gradually became longer as the vesicle grew in size. The internal bodies (daughter cells) underwent several successive divisions within the vesicle, which was accompanied by the simultaneous growth of both vesicle and processes. The regular growth of cells, formation and release of daughter cells, and the remarkable morphological similarity between extant algae and the studied microfossils suggest that Yurtusia uniformis is probably a green microalga that may be closely related to the Trebouxiophyceae or even Chlorellales (Chlorophyta). The growth and reproductive mode of individuals indicates that Y. uniformis is an actively growing vegetative cell of microalgae, rather than a metabolically inert cyst or resting spore. A life cycle involving vegetative growth and asexual reproduction is proposed for Y. uniformis on the basis of the life histories of modern chlorophytes. The multiple internal cells may represent autospores produced by a mature autosporangium during asexual reproduction, which subsequently developed into separate young vegetative cells after their release from the opened autosporangium.

中文翻译：

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华南地区寒武纪初生鱼腥草的藻类亲和力和可能的生命周期

球形有机壁微化石尤里特氏菌的丰富，保存完好的标本从华南湖北省长阳地区的基底寒武纪燕家河组报道。薄而空心的过程在囊泡的双壁之间延伸。囊泡腔内的单个到多个内部实体是首次在属中观察到，代表生殖结构（分裂子细胞）。在囊泡壁上可能会出现一个小的圆形穿孔，以释放内部物体。对在不同生命阶段保存的标本进行形态分析表明，随着囊泡大小的增加，过程逐渐变长。内部小体（子代细胞）在小囊内经历了连续的分裂，伴随着小囊和过程的同时生长。细胞的正常生长，子细胞的形成和释放，尤里特氏菌可能是一种绿色的微藻，可能与蝶形藻科甚至小球藻（Chlorophyta）密切相关。个体的生长和繁殖方式表明统一的耶氏酵母是微藻的活跃生长的营养细胞，而不是代谢惰性的囊肿或静止的孢子。根据现代绿藻类植物的生活史，提出了一种针对猪油单胞菌的营养生长和无性繁殖的生命周期。多个内部细胞可能代表了成熟的自孢子囊在无性繁殖过程中产生的自孢子，在从开放的自孢子囊中释放出来后，这些孢子随后发育成独立的年轻营养细胞。