Late Famennian rhynchonellides (Brachiopoda) of northeast Iran

The late Famennian Sarcheshmeh Member of the Khoshyeilagh Formation contains a sizeable rhynchonellide component comprised of eight genera and ten species, including Golestanirhynchus golestanicus sp. nov. Petasmaria sartenaeri sp. nov. Tilabadirhynchus azadshahrensis gen. et sp. nov. Tilabadirhynchus qeshlaqensis gen. et sp. nov. and Megalopterorhynchus chanakchiensis giganteus subsp. nov. The characters of brachiopod biostratigraphical distribution in the Sarcheshmeh Member and correlation with conodont biozonation suggest that Megalopterorhynchus chanakchiensis giganteus does not cross the lower boundary of the Bispathodus ultimus Zone, while Araratella anatolica is probably confined to it. The pugnacoidean genus Petasmaria is reported for the first time outside of North America. The broad paleobiogeographic affinities of the late Fammenian rhynchonellide assemblages from the Sarcheshmeh Member of the Alborz Region with the contemporaneous brachiopod faunas of Central Iran, Afghanistan and Transcaucasia corroborate the well-established pattern of increasing cosmopolitanism of the brachiopod faunas towards the end of the Devonian Period.