Organic-walled microfossils offer important information on the biospheric evolution in pre-Cryogenian and provide biostratigraphic implications for many Proterozoic fossiliferous sequences that are poorly age constrained for the lack of reliable radiometric date. Recently, macroscopic carbonaceous compression fossils have been reported for the first time from the Tonian Shiwangzhuang Formation of the Tumen Group in western Shandong, North China. However, organic-walled microfossils have never been discovered from this formation up till now. To improve our knowledge about Proterozoic biodiversity in North China, we conducted a micropaleontological survey on the argillaceous limestone samples of the Shiwangzhuang Formation, which also contain macroscopic carbonaceous compression fossils, from the Baishicun section in Anqiu, western Shandong, North China. Our investigation shows that the Shiwangzhuang microfossil assemblage is dominated by smooth-walled sphaeromorphic acritarchs and cyanobacterium-like filaments and relatively low abundance of other acritarchs, including 16 taxa, such as Polysphaeroides filliformis, Ostiana microcystis, Simia annulare, ?Jacutianema sp., Arctacellularia tetragonala, Pellicularia tenera, Polythrichoides lineatus, and Navifusa actinomorpha. The Shiwangzhuang organic-walled microfossil assemblage, although consisting of long-ranging and not age diagnostic taxa, is consistent with a Tonian age suggested by macroscopic carbonaceous compression fossils, including the Chuaria-Tawuia and Sinosabellidites-Protoarenicola-Pararenicola assemblages, revealed from the same fossiliferous horizon of the Shiwangzhuang Formation and by organic-walled microfossil assemblage, including the late Mesoproterozoic to Tonian index fossil Trachyhystrichosphaera aimika, from the underlying Tongjiazhuang Formation. However, it is also worth noting that a Cryogenian or Ediacaran age cannot be completely excluded based just on the Shiwangzhuang microfossils because of their limited biostratigraphic utility.

有机壁微化石提供了关于前低温纪生物圈演化的重要信息，并为许多元古代化石序列提供了生物地层学意义，这些序列由于缺乏可靠的放射性数据而受到年龄限制。近来，首次报道了华北鲁西图们群托年石王庄组宏观碳质压缩化石。然而，迄今为止，从未在该地层中发现有机壁微化石。为了提高我们对华北元古代生物多样性的认识，我们对鲁西安丘白石村剖面的石王庄组泥质灰岩样品进行了微观古生物调查，该组还含有宏观碳质压缩化石，华北。我们的调查表明，石王庄微化石组合以光滑壁球状acritarchs和蓝藻样细丝为主，其他acritarchs丰度相对较低，包括16个分类群，如Polysphaeroides filliformis, Ostiana microcystis, Simia ringe , ? Jacutianema sp.、Arctacellularia tetragonala、Pellicularia tenera、Polythrichoides lineatus和Navifusa actinomorpha。石王庄有机壁微化石组合，虽然由分布广泛且没有年龄诊断的分类群组成，但与宏观碳质压缩化石所暗示的托尼安时代一致，包括Chuaria - Tawuia和Sinosabellidites - Protoarenicola - Pararenicola组合，来自石王庄组的同一化石层和有机壁微化石组合，包括中元古代晚期至托尼阶指数化石Trachyhystrichosphaera aimika，来自下伏的通家庄组。然而，同样值得注意的是，由于其生物地层学实用性有限，不能仅根据石王庄微化石就完全排除低温纪或埃迪卡拉纪时代。