The Lochkovian–Pragian boundary in Podolia (Lower Devonian, Ukraine) based upon placoderm vertebrates

Identifying stratigraphic boundaries within the Old Red Sandstones facies of Podolia (Ukraine) is problematic. Commonly used stratigraphic markers such as conodonts are indeed sparse or absent from this facies. The placoderm vertebrate Kujdanowiaspis buczacziensis (Brotzen, 1934) is proposed here as an index for the beginning of the Pragian.