Serrakielina chahtorshiana n. gen. et n. sp., and other (larger) benthic Foraminifera from Danian-Selandian carbonates of Mount Chah Torsh (Yazd Block, Central Iran)

Abstract

Mount Chah Torsh in the Yazd area of Central Iran exposes the Cretaceous-Paleogene boundary within a carbonatic siliciclastic shallow-water succession. From the territory of Iran the K/Pg boundary was so far only recorded from deeper-water successions of the Kopet Dagh Basin in the northeast and the Zagros Zone (Gurpi Formation) in the southwest. From the Paleocene (Danian–Selandian, Shallow Benthic Zones 1–2) carbonates of Mount Chah Torsh the new porcelaneous Larger Benthic Foraminifera Serrakielina chahtorshiana n. gen. et n. sp. is described. In the uniserial adult part the chambers are subdivided by radial partitions. Together with the single, stellate foramina Serrakielina n. gen. compares closely to the soritacean Praerhapydionina Henson. It differs in its juvenile stage (trochospiral in the former vs. planispiral in the latter). From the same section, Haymanella ex. gr. paleocenica Sirel, Kolchidina paleocenica (Cushman), Sistanites iranicus Rahaghi, Orduella sphaerica Sirel, and other taxa (rotaliids, miliolids) are reported. Anew larger agglutinated taxon is described as Socotraella? yazdiana n. sp. Socotraella ashawqi the type-species of the genus was described from the Lower Oligocene of Yemen (Socotra Island) and Oman. The samples from the Mount Chah Torsh section also display a comparably rich association of Dasycladales and other algae. The locality can be considered a standard section for Danian–Selandian shallow-water carbonates in Iran. Exposing also the K/Pg boundary in a conformable transition, this locality offers several topics for future research.