The paper presents a new fossil find of Properca angusta (Ag.) (Pisces) found in sediments at Euxinograd Formation with Miocene (Sarmatian) Age. The paleogeographic picture across the Sarmatian is related to the existence of a semi-isolated Euxinian basin, with periodic changes in the hydrological regime –from saline to refreshed waters. The established bony fish marks a stage in the refreshment and splicing of the Euxinian basin and proves how changing the hydrodynamic conditions has led to adaptive changes in the qualitative and quantitative composition of the fauna. The paleontological description and paleoecological value of the specimen allows to interpret the palaeogeographic conditions of the Euxinian basin, which is a residual sleeper of the Crimean-Caucasian type of Sarmatian basin (Eastern Paratethys).
Key words: Pisces, Properca angusta , Miocene, Sarmatian, Varna region
Topic: GEOLOGY