TY JOUR TI Subdivision of the Lower and Middle Givetian deposits of the Vysotinsky regional stage by conodonts in the Pokrovskoye section (Middle Urals) KW conodonts KW Middle Devonian KW Givetian KW varcus Zone KW Vysotinsky regional stage KW Middle Urals JO Vestnik of geosciences AU Sharipova, A.R. PY 2026 IS 0 PB FSBI FIC "Komi Scientific Center of the Ural Branch of the Russian Academy of Sciences"