Lectotype designation for Orbitolinopsis flandrini Moullade, 1960 (Foraminifera): The missing piece of a taxonomic puzzle

Abstract

Orbitolinopsis flandrini Moullade, 1960, was described from Lower Cretaceous Urgonian limestones of southeastern France without the designation of a holotype. It represents a valid taxon since the selection of a holotype is only obligatory for taxa established after 1999 (ICZN, 4th edition, article 72.3). Today the original description is considered to be a mixture of several taxa belonging to Orbitolinopsis Henson, 1948/Cribellopsis Arnaud-Vanneau, 1980 (transverse sections with cupules/septules in the central zone) and Drevennia Arnaud-Vanneau, 1980 (axial sections with an axial columella-like column). The short and in any case insufficient original description of O. flandrini, however, stressed the presence of a columellar-like central test as the main characteristic feature. In fact, the majority of the (sub)axial sections showing an axial column (lacking in Orbitolinopsis) are considered to belong to Drevennia (Family Pfenderinidae). Therefore, the new combination Drevennia flandrini (Moullade, 1960) is proposed and a lectotype herein designated from the original illustrations. Drevennia ecougensis, the type-species of the genus, is found to be a subjective junior synonym of the latter. New finds from Serbia and Spain extend the stratigraphic range of D. flandrini, from the upper Berriasian to the lowermost upper Aptian. The first occurrences of Drevennia, Dobrogelina Neagu, 1979, Pfenderina Henson, 1948, and Moulladella Bucur & Schlagintweit, 2018, in the upper Berriasian give evidence for an adaptive radiation of the Pfenderinidae during the time reported and from other, mostly complex larger benthic foraminifera (e.g., Orbitolinidae).