Introduction of Three species of Omphalucyclus from Tarbur Formation in Semirom section (southwest of Isfahan) by comparison of Morphometric data of this genus in the Tethys area

In the Upper Maastrichtian (Tarbur Formation) Omphalocyclus is very abundant in carbonate sequence of the Tethys realm. Omphalocyclus is a orbitoidal benthic foraminifers which existed in the outer platform environment commonly found with rudist, echinoderms and other foraminifers. In this study, based on the morphometric data, Omphalocyclus antoliensis, Omphalocyclus cideensis and Omphalocyclus macroporus are recognized at the study area which suggest Late Maastrichtian age for the Tarbur Formation. Among these species, Omphalocyclus anatoliensis and Omphalocyclus cideensis species are reported for the first time from Iran. Additionally, Omphalocyclus macroporus will be revised systematically and scientifically.