Precambrian Research ( IF 4.427 ) Pub Date : 2020-10-17 , DOI: 10.1016/j.precamres.2020.105968 Shu Chai; Hong Hua; Jinjie Ren; Qiaokun Dai; Zaihang Cui
The origin and early evolution of protists are shroud in misty. The oldest evidence of heterotrophic protists may be the vase-shaped microfossils (found in Early Neoproterozoic sedimentary rocks around the world (c. 780–720 Ma). Here we explore the taxonomy, taphonomy and biological affinity of vase-shaped microfossils from the Dengying Formation of the Gaojiashan biota, Ningqiang, China. Species from Dengying Formation are Protolagena limbata, P. gaojiashanensis, P. papillata, Sicylagena formosa and S. latistoma. Founded in siltstone beds horizons and clastic dolomite, sedimentological data suggest these vase-shaped microfossils inhabited a series of preservational pathways including calcification, silicification, phosphatization and pyritization. The fossiliferous strata have recently been dated with U-Pb age of 548 ± 8 Ma, which indicates they are not coeval with diverse vase-shaped microfossils assemblages described in other regions worldwide, but also provides supportive evidence for the early diversification of possible protozoa foraminifera clades follow on the Gaskiers age Snowball Earth event (c. 590–580 Ma).