Writers : Kebria-ee Zadeh,M. R.
Refference : Geosciences Scientific Quarterly Journal,No.:56,P.:168
Publishing Year : 1384

Abstract :

Frasnian deposits are very widespread in Iran (Central Iran and Alborz Range) and brachiopoda (specially Rhynchonellida) are considered as their index fossils. The genera: Cyphoterorhynchus,Ripidiorhynchus,Paropamisorhynchus,Coeloterorhynchus,Lateralatirostrum and Ladogilina are Frasnian Rhynchonellid of Iran, that their geographic and stratigraphic distribution were studied, and their biozonations were based on the Brice (1977) in Afghanistan. Two genera: Ripidiorhynchus and Cyphoterorhynchus have more species as well as wide distribution. Hence they have more biostratigraphici importance than other genera. Also the Coeloterorhynchus genus has shorter age extent (Late Frasnian) than other genera.
Consequently, the Rhynchonellida have very biostratigraphical applications in Iran and even in the Word, because of their extensive geographic distribution and short age extent.

Subject List : Rhynchonellida