An overview on graptolite zones in the Prague Basin is done. As the rests of graptolites are preserved nearly exclusively in the clayey shale facies of the Klabava, Š árka and Dobrotivá Formations, a reasonable graptolite zonation is establish only in thee.
Revised biostratigraphical scheme is proposed for this part of the Bohemian Ordovician. Only two zones are distinguished inside the Šárka Formation.