Paleontological Institute of the Russian Academy of Sciences, Profsoyuznaya ul., 123, Moscow 117647 Russia

Abstract

The major types of Precambrian colonial microfossils are characterized. Relation between the kind of cell division and the cell interactions in colony and shape of colony is considered. The ancient Archean benthonic colonies were formed as a result of monotomic division in two fission planes. The ancient known ball-like (possibly planktonic) colonies were formed as result of palintomic division in three of several fission planes. Bottom-dwelling palmella-like colonies had appeared at the beginning of the Early Proterozoic and planktonic ones were known since the Riphean only. Riphean and Vendian planktonic ball-like and spherical colonies are described.