Kasimovian (Upper Pennsylvanian) Conodonts of the Shcherbatovka Section (Oka-Tsna Swell)

Kasimovian (Upper Pennsylvanian) conodonts are studied from the Shcherbatovka section (Oka-Tsna Swell, Ryazan Region). The Khamovnikian and Dorogomilovian substages are exposed in this section. The presence of the conodonts Idiognathodus turbatus and I. heckeli was established in the deeper-water facies, compared to the type area of the Khamovnikian Substage. These species are considered as the potential markers for the lower boundary of the global Kasimovian Stage of the Carboniferous. A similar assemblage is established in the sections of US Midcontinent and South China.