Rudist bivalves (Requieniidae family) in Early Cretaceous sediments from SW Qayen, Eastern Iran, Paleobiogeographic aspects

In order to study Early Cretaceous rudists in east of Iran, a section in southwest of Qayen has been selected and measured. The thickness of section is about 81 meters. The sequence is including of: conglomerate, sandstone and massive limestones with rich fauna of rudists, gastropods and foraminifera (orbitolinid). Based on systematic investigations two genera and four species related to rudists consist of Pseudotoucasia catalaunica, Pseudotoucasia santanderensis, Pseudotoucasia sp. and Toucasia carinata have been identified. Late Aptian age is suggested for studied section with respect to the identified taxa of rudists, orbitolina species, and stratigraphic position. The recognized rudists show resemblances to those are reported from Tethian realm, especially from northern margin of Tethys. This similarity confirms fauna relationship among these areas.