Mature Bicellum brasieri . In image A, the boundary between the outer cell layer and the internal cell cluster can be clearly seen. In image E, the arrangement of the sausage-shaped elongated cells is clearly visible. (Image source: Strother, P. K. et al. (2021). ，採用  CC BY 4.0  授權） Age Proterozoic (Neoproterozoic) 1000 Ma Taxonomy Domain：Eukaryota Genus： Bicellum Species： Bicellum brasieri Morphological description The outermost layer of Bicellum brasieri consists of thicke