A new bryozoan species Dianulites altaicus sp. nov. (order Esthonioporata) is described from the Sandbian Stage of the Upper Ordovician of the environs of Lake Teletskoe in Gorny Altai. A collection of bryozoans of the genus Dianulites Eichwald, 1829 from the Lower and Middle Ordovician of the Novaya Zemlya archipelago and Vaygach Island in the Russian Arctic has been revised. Bryozoans from the Lower and Middle Ordovician of the Novaya Zemlya archipelago previously classified as D. janischevskyi Modzalevskaya, 1953 were shown to belong to D. altaicus sp. nov. Two groups of species of the genus Dianulites have been identified in the Ordovician of the Russian Arctic: the representatives of the first group had mesozooecia, whereas the representatives of the second group, which includes the new species, did not have mesozooecia, but some of them had minutopores.