Demirina meridionalis Özcan, 1994, Cenomanian larger benthic foraminifera from the Natih Formation of Oman: First record outside the type area and emendation of the genus

Abstract

Demirina meridionalis Özcan, 1994 is the only known species of the larger benthic foraminifera genus Demirina Özcan, 1994. It was described as a nezzazatid (subfamily Coxitinae) from the Cenomanian of SE Turkey (Arabian Plate margin) based on limited and rather poorly preserved material. Several well-preserved specimens of D. meridionalis are found in the Cenomanian Natih Formation (members E to B) of Oman. A close architectural analysis of these fossil shells displays a short single rafter in the marginal chamber part, and beams generally aligned between subsequent chambers, which allows the transfer of Demirina to the order Loftusiida, and the family Spirocyclinidae. Reissella ramonensis Hamaoui, 1963, another little known loftusiid larger benthic foraminifera first described from the Cenomanian of Israel, as well as Spirocyclina atlasica Saint-Marc and Rahhali 1982 first reported from the Cenomanian of Morocco, are shown to differ from Demirina mainly by their test morphology and chamber shape. The Omani material represents the first record of D. meridionalis outside its type area in southeastern Turkey; a paleogeographic restriction to the former Arabian Plate is suggested, and a stratigraphic distribution ranging from the uppermost early to middle Cenomanian is proposed.