Biostratigraphic significance of the tetrapod assem¬blages of the Timan- North Urals region and adjacent areas

Abstract

New and specified data on the composition of the Triassic tetrapod assemblages of the Timan-North Urals region, the Mezen syneclise and the eastern part of the Moscow syneclise have been given. The succession of the Triassic tetrapod communities known in this area includes eight assemblages, seven of which correspond to the contemporary communities of the terrestial vertebrates known from other regions of the East European platform and the Cisurals. The first assemblage, known from the basal Triassic of the Mezen and Moscow syneclises, is Early Induan in age. The second, third and fourth assemblages are dated by Early Olenekian age and typical for the middle part of the Early Tri-assic section of the Timan-North Urals region, the Mezen and Moscow syneclises. The Late Olenekian fifth and sixth assemblages characterize the upper part of the Lower Triassic of the Northern Cisurals, the Moscow and Mezen syneclises. The seventh assemblage characterizes the base of the Middle Triassic (Lower Anisian) of the Northern Cisurals and has no analogues in other regions of the platform and of the Cisurals. The eighth assemblage is known from the upper part of the Middle Triassic of the Northern Cisurals and is Late Ladinian in age.