Evolution of the morphology of ancient cyanobacteria and its significance for biostratigraphical compositions in the late Precambrian

摘要

The biostratigraphical significance of individual taxa of Precambrian microorganisms has been considered. The results of an analysis of the morphological variability of ancient colonial forms are comparable to present-day coccoidal cyanobacteria of the Gloeocapsa Kutz. genus. Conclusions have been made on the origin, nature, and direction of changes in the Gloeocapsa-shaped colony composition as well as on an opportunity to use them for biostratigraphical purposes.