IntroductionLarger agglutinated conical benthic foraminifera are a typical constituent of Paleogene inner platform carbonates (e.g., Hottinger and Drobne, 1980;Vecchio and Hottinger, 2007;Powell, 2010). As in the Lower and Upper Cretaceous (e.g., Cherchi et al., 1981), the representatives of the Dictyoconinae displayed a biogeographic distribution pattern during the Paleogene with different assemblages on both sides of the Atlantic Ocean (e.g., Carribean Bioprovince, Hottinger and Drobne, 1980; Goldbeck and Langer, 2009, Figure 27) for this group of agglutinated conical foraminifera. Paleocene taxa (e.g., Coskinon, Dictyoconus, Fallotella, and Karsella) have been reported from the Taurides of Turkey (provinces of Elazığ and Kars) (e.g., Sirel, 2015). Assemblages of Middle Eocene (Bartonian) larger benthic foraminifera (LBF), including Orbitolinidae, have been studied from the Hoya Formation in SE Turkey (north eastern Diyarbakır), belonging to the northernmost part of the Arabian Plate (Özgen-Erdem and Sinanoğlu, 2016;Sallam et al., 2018). Large-sized dictyoconids, previously referred to as Dictyoconus aegyptiensis (Chapman), usually occur above limestones with Somalina stefaninii Silvestri. They have been recognized as Rogerella aydimi Gallardo-Garcia and Serra-Kiel, as described recently in Serra-Kiel et al. (2016), from the Middle-Upper Eocene of Oman. The present findings from Turkey represent the first discovery of its type-locality. The aim of the present study was to 1) comment and revise its taxonomic status and 2) constrain its paleobiogeographic distribution, also including further specimens from the Jahrum Formation in Iran.
Geological setting 2.1. Geological overviewThe south eastern Anatolian region forms the northern part of the Arabian Platform (Figure 1A) and consists of the Bitlis-Pütürge Crystalline Melange, Precambrian Basement, and Early Paleozoic-Cenozoic sedimentary deposits (Rigo de Righi and Cortesini, 1964;Sungurlu, 1974;Şengör and Yılmaz, 1981). The geological framework of this region was shaped by the Late Mesozoic and Cenozoic closure of the multibranched Neotethyan Ocean (Şengör and Yılmaz, 1981). Important folding structures developed during the Neotectonic period as a result of the N-trending compressional tectonic regime. The Cambrian, Aptian-Cenomanian, Campanian-Maastrichtian, and Middle Eocene periods are represented by marine sequences, which indicate widespread transgression Abstract: Rogerella aydimi Gallardo-Garcia and Serra-Kiel was described from the Priabonian Haluf Member of the Aydim Formation, Oman. Based on new finds from the Bartonian Hoya Formation of SE Turkey and the Jahrum Formation of Iran, its taxonomic status is discussed herein. It is concluded that it represents a species of Dictyoconus with a simple subepidermal network (1 rafter, 1 intercalary beam) below a thin epiderm. The stratigraphic range of D. aydimi known thus far is Bartonian-Priabonian or Shallow Benthic Zone 17-20. The distribution of D. aydimi gives further evidence for a Middle-Late Eocene ...