Biogeography and evolution of bryozoans of the genus <Emphasis Type="Italic">Minussina</Emphasis> Morozova, 1961

The spatial variations of bryozoans of the Devonian genus Minussina throughout its existence are discussed. The areal distribution of Minussina is shown to be restricted mainly to the Altai-Sayan region. The variability of seven morphological characters of Minussina species is analyzed. The variations in the number of acanthozooecia and in the thickness of walls are attributed to evolutionary change; variations in the measurements of apertures and heterozooecia are explained by geographical variation. The narrow stratigraphic range of Minussina species makes it possible to use them for correlation of Devonian deposits.