Early-middle Ediacaran organic-walled microfossils from the Doushantuo Formation studied in several sections in the Yangtze Gorges area, South China, show ornamented cyst-like vesicles of very high diversity. These microfossils are diagenetically permineralized and observed in petrographic thin-sections of chert nodules. Exquisitely preserved specimens belonging to seven species of Appendisphaera, Mengeosphaera, Tanarium, Urasphaera and Tianzhushania contain either single or multiple spheroidal internal bodies inside the vesicles. These structures indicate reproductive stages, endocyst and dividing cells, respectively, and are preserved at early to late ontogenetic stages in the same taxa. This new evidence supports the algal affiliations for the studied taxa and refutes previous suggestions of Tianzhushania being animal embryo or holozoan. The first record of a late developmental stage of a completely preserved specimen of T. spinosa observed in thin-section demonstrates the interior of vesicles with clusters of identical cells but without any cavity that is diagnostic for recognizing algal cysts vs animal diapause cysts. Various lines of evidence to infer biological affinities of these microfossils – morphology, reproductive characters, spatial arrangement of cells, and biochemical properties of the vesicle wall – are collectively characteristic of algal clades. Recognizing the biological affinities of these microfossils is key to understanding whether animals capable of producing such morphologically complex diapause cysts had an early Ediacaran fossil record (633–610 Ma), or the microfossils were non-animal holozoans or algae as argued herein for Tianzhushania spinosa and other studied microfossils.

在华南长江三峡地区的几个剖面研究的陡山沱组早-中期埃迪卡拉纪有机壁微化石显示出具有高度多样性的装饰性囊状囊泡。这些微化石是成岩作用的，并在燧石结节的岩相薄切片中观察到。保存精美的标本，分属附球纲、门叶纲、塔那拉目、乌拉氏球纲和天竺山属七种。囊泡内含有单个或多个球形内部体。这些结构分别表示生殖阶段、内囊和分裂细胞，并在同一分类群的早期至晚期个体发育阶段保存。这一新证据支持了所研究类群的藻类从属关系，并驳斥了先前关于天竺葵是动物胚胎或全虫的说法。完整保存的棘刺枇杷标本的晚期发育阶段的第一个记录在薄切片中观察到的囊泡内部具有相同的细胞簇，但没有任何腔，可用于识别藻类囊肿与动物滞育囊肿。推断这些微化石的生物学亲和力的各种证据——形态、生殖特征、细胞的空间排列和囊泡壁的生化特性——是藻类进化枝的共同特征。认识到这些微化石的生物亲和力是了解能够产生这种形态复杂的滞育囊肿的动物是否具有早期埃迪卡拉纪化石记录（633-610 Ma）的关键，或者这些微化石是非动物全息动物或藻类，如本文所讨论的棘刺天竺葵和其他研究过的微化石。