Coloniality of Precambrian planktonic unicellate microorganisms

The major types of Precambrian colonial microfossils are characterized, Rel ation 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 an cient 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 Proterozo ic and planktonic ones were known since the Riphean only. Riphean and Vendi an planktonic ball-like and spherical colonies are described.