A series of questionable elements in certain specimens ofMorone cf.aequalis (Koken 1891) from Lower Miocene deposits near the village of Berkersheim, N of Frankfurt a. M. (Hessen, Germany) is described, which has not been known from any other percoid before. These elements are fully ossified and cover the cheek and the preopercular region. Even within well-preserved material, they are only present in some specimens. Therefore, they may be specialized structures that are indicative for sexual dimorphism. Nevertheless, they clearly differ from all other respective structures that have been described from teleosts: Multicellular epidermal horny tubercles (“breeding tubercles”) mainly consist of keratine and not of calciumphosphate. By contrast, contact organs consist of bone and are located mainly at the surface of the fin rays and scales, respectively. At present, “breeding tubercles” are the favorite interpretation and the original substance may have been replaced via post-mortem phosphatization.