ORBITOLINA DAVIESI HOFKER, 1966: A FORGOTTEN ORBITOLINIDAE FROM THE THANETIAN OF PAKISTAN AND ITS TAXONOMIC STATUS

Orbitolina daviesi Hofker, 1966 (family Orbitolinidae) was validly described and thoroughly illustrated from Thanetian limestones of Pakistan. Although its attribution to the genus Orbitolina d’Orbigny and any phylogenetic relationships with the Cretaceous taxa have been refuted shortly afterwards, the species has not been taxonomically revised since then. Karsella hottingeri Sirel, 1999 was established as new genus and new species from the Thanetian of Turkey, without taking into account J. Hofker’s publication. The original description and genus diagnosis of Karsella has meanwhile been emended to include the occurrence of a radial zone with septula that follow a zig-zag pattern and associated linear arrangement of the foramina, as well as a complex embryo. Orbitolina daviesi clearly displays these features and is here considered a species of the genus Karsella Sirel. Karsella hottingeri is regarded as a subjective junior synonym of O. daviesi Hofker and therefore, the only species of the genus is given as a new combination: Karsella daviesi (Hofker). From a suprageneric viewpoint, the two Paleogene genera Karsella Sirel and Cushmania Silvestri display a complex embryo and might belong to a new subfamily of the Orbitolinidae, phylogenetically different and unrelated to the lower-mid Cretaceous Orbitolininae.