Mid-Cretaceous echinoids from the Dhalqut Formation of Dhofar, southern Oman - Taxonomy and biostratigraphical implications

Several small echinoid faunules are recorded from the Umbaraaf and Khadrafi members of the Dhalqut Formation, the upper unit of the Albian-Turonian Qamar Group in the eastern part of the Jeza-Qamar Basin of Dhofar (southern Oman). In all, 11 species, in nine (sub)genera, are described: Arabicodiadema dhofarense (Roman), Arabicodiadema romani Smith and Jagt n. sp., Heterodiadema libycum (Desor, in Agassiz and Desor), Emiratia raskhaimahensis Ali, Orthopsis miliaris (d'Archiac), Pedinopsis (P.) sphaerica Smith, Simmons and Racey, Pedinopsis (Sinaiopsis) sinaica (Desor, in Agassiz and Desor), Goniopygus dhalqutensis Smith and Jagt n. sp., Coenholectypus excisus (Desor, in Agassiz and Desor), Coenholectypus larteti (Cotteau) and Pliotoxaster dieneri (de Loriol). These novel echinoid data suggest that the Umbaraaf Member extends into the Cenomanian, thus supplementing previous biostratigraphical dating based on foraminifera. The echinoid fauna also suggests correlation of the Umbaraaf and Khadrafi members with strata such as the Natih Formation in north-central Oman, the Mauddud Formation of the northeastern United Arab Emirates, the Galala Formation of the North-Eastern Desert of Egypt and the Wasia Formation of central Saudi Arabia.