Conodonts of Khoshyeilagh Formation, the most complete section of Devonian rocks in the Alborz Mountains, northern Iran, has been studied, and subspecies of the genera Icriodus, Bipennatus, Polygnathus, Pelekysgnathus, Ancyrodella, Palmatolepis, Bispathodus, Scaphignathus, Clydagnathus, Gnathodus, Scaliognathus and Dollymae have been obtained from the studied section. The faunas indicate an Eif...