Well exposed Tournaisian, mainly carbonate, rocks of the Mobarak Formation in the area of Shahmirzad village, Central Alborz, Iran, yielded almost 200 chondrichthyan teeth and scales, associated with numerous actinopterygian microremains. Ten different taxa were recognised among the chondrichthyan teeth, of which the most abundant are those representing Euselachii (Protacrodus and Lissodus), Symmoriiformes (Denaea), and Phoebodontiformes (Thrinacodus). The high relative abundance of protacrodont crushing teeth, but lack of holocephalian dental elements suggest that the sediments forming the Shahmirzad section were deposited in a shallow shelf environment, but probably not on a carbonate platform.
