The nuclear ITS1-5.8S-ITS2 DNA region is studied for 29 specimens of Coscinodon from Eurasia, mostly from Russia, and 4 specimens from North America. The sequences were found to be much less variable than in two other genera of the Grimmiaceae, Grimmia and Schistidium. Coscinodon yukonensis Hastings was found to be rather widespread in Asia, despite never having been reported before in this continent, being erroneously treated as C. humilis Milde. European C. humilis is quite distinct molecularly from Asian C. yukonensis and forms a sister clade to C. cribrosus (Hedw.) Spruce. Some Asian populations of "C. cribrosus" were unresolved, being found outside the main clade formed by C. cribrosus and C. humilis. Coscinodon hartzii C.E.O. Jensen forms a basal grade to the rest of the species in the genus. Coscinodon pseudohartzii is described as a species new to science from Siberia.