Rare and Endemic Elements in Triassic Tetrapod Assemblages of Obshchii Syrt Highland (Eastern Europe)

Abstract

© 2020, Pleiades Publishing, Ltd. Abstract: The historical sequence of Early Triassic tetrapod communities in the Obshchii Syrt area includes eight consecutive faunal assemblages: this degree of detail in the identification of evolutionary stages is unique on a global scale. Temnospondyl amphibians are the dominant elements in these tetrapod assemblages, with three capitosauromorph groups (capitosaurids, benthosuchids, and trematosaurids) characterized by the widest distribution. Reptile remains are much less frequent. The paper provides a brief overview of the findings of rare and endemic tetrapod groups known from the Lower Triassic of Obshchii Syrt. These include amphibians (qantasids, lonchorhynchids, selenocarine capitosaurids, rhytidosteids, plagiosaurs, some forms of benthosuchids and trematosaurids, and chroniosuchians, the relict anthracosaurs) and reptiles (eosauropterygians, theriodonts, individual procolophonid, protorosaurian, and thecodontian genera). The peculiarity of the systematic composition of the Early Triassic tetrapod communities of Obshchii Syrt and Southern Cis-Urals with respect to that of the coeval fauna of terrestrial vertebrates of the more northern regions of Eastern Europe is emphasized, as is the legitimacy of considering these two areas as a specific region characterized by the distinctive character of their zoogeographical connections.