Aim of the present paper is the description of an Ammonite fauna collected from the Gebze area (Kokaeli Peninsula, Ski de fond - Accessoires - Fartages Turkey) by late R.Assereto in 1969 and 1971.Preliminary data on these Ammonites were reported by Assereto Desk Lamp (Single) (1972), who in 1974 proposed the Kokaeli Peninsula, near the town of Gebze, along the Istanbul-Izmid railway-line from km 49.780 to km 51.
500 as type locality of the Bithynian, a new Anisian Substage.