The phylogenetic history of the Eocene foraminiferal genus LinderinaSchlumberger, with a widespread global distribution from the Central America region to SE Asia and Australia, is little known despite numerous but yet fragmentary and non-continuous records. We herein show that Linderinaoccurs in the Ypresian Ayhan Formation in the Kozaklı Basin, Central Turkey, which challenges the current notion that the genus is diagnostic to middle and upper Eocene in the Neo-Tethys. Linderinahas a limited stratigraphic distribution in the Ayhan Formation but occurs abundantly in one level in the lower part of the studied succession. The associated larger foraminifera and assemblages below and above the stratigraphic level of Linderinaare represented by nummulitids, orthophragminids, alveolinids and rotaliids characterizing the shallow benthic zone (SBZ) 10 that corresponds to the lower part of the upper Ypresian. Linderinain the studied material is represented by two morphotypes (Morphotypes 1 and 2), differentiated by the early chamber arrangement. There is a notable difference in the size of the trilocular embryonic apparatus of these types as documented biometrically. Comparing these morphotypes with most of the previously established species in the Tethys is not straightforward because of inadequate information of their internal test features. Linderinafrom some well-dated younger stratigraphic levels of Bartonian age in NW Turkey suggests the persistence of similar morphotypes during the phylogenetically younger stages of the genus.