Postcranial Osteoderms of Late Permian Pareiasaurs from Eastern Europe – I. Chronology of Localities

To clarify the chronological sequence of East European localities of late Permian pareiasaurian osteoderms, a stratigraphic analysis of the osteoderm-bearing strata was carried out. Thirty localities have been dated with maximum accuracy, which characterize eight successive stratigraphic levels – the Vanyushonkian, Syominian and Kichugian beds of the Putyatinian Regional Stage (Upper Severodvinian), Chizhian and Rovdinian beds of the Bykovian Regional Stage (Lower Vyatkian), Aristovian and Gorokhovetsian beds of the Nefyodovian Regional Stage (Upper Vyatkian), and Lagernian beds of the Zhukovian Regional Stage (Upper Vyatkian).