DICTYOCONELLA HENSON, 1948, UPPER CRETACEOUS LARGER BENTHIC FORAMINIFERA: A TAXONOMIC REVISION WITH THE ESTABLISHMENT OF GUSICELLA GEN. NOV. (TYPE-SPECIES DICTYOCONELLA MINIMA HENSON)

Abstract

In his monograph on Mesozoic-Cenozoic Larger Benthic Foraminifera from the area of Middle East and south-western Asia, Henson (1948) erected the genus Dictyconella for more or less "compressed-conical" dictyoconids including D. complanata (type-species) and D. minima. Both are however, structurally completely different, e.g. aligned (in the latter) versus alternating structural elements (in the former), and cannot either belong to the same genus or the same subfamily (Dictyoconinae versus Dictyorbitolininae). Therefore, the new genus Gusicella is erected with the type-species Dictyoconella minima, resulting in the new combination Gusicella minima. Gusicella represents the only taxon of the Dictyorbitolininae in the Upper Cretaceous Global Community Maturation Cycle of Larger Benthic Foraminifera (here: conical agglutinated). Due to the revision, Dictyoconella is described as a monospecific genus and an assumed Maastrichtian newcomer which, like Gusicella, became extinct shortly afterwards, namely at the K-Pg boundary mass-extinction event. Both taxa appear to be restricted to the former Arabian Plate of the southern Neotethyan margin. The new data provided are based on material from the Maastrichtian Tarbur Formation of southwestern Iran (Zagros Zone).