EOTHERAPSIDS FROM THE EAST EUROPEAN PLACKET (LATE PERMIAN)

Abstract

The collections of primitive therapsids from the Upper Permian of Eastern Europe are revised. Morphological examination has shown that the main principles for the establishment of the subclass Theromorphu should be revised. The revision of the definition and systemalies of this group is based on reconstructed trends in the formation of its general syndrome. The Theromorpha is considered to comprise two infraorders, Eotherapsida and Therapsida (= Eutherapsida). The infraorder Eotherapsida includes the Sphenacodontia, Dinocephalia, Gorgonopia, and Anomodontia. A complete catalogue of the Eotherapsida from the Late Permian of Eastern Europe is given. The study of the Upper Permian oryctoassemblages containing the Eotherapsida provided the reconstruction of faunal assemblages and letrapod communities replacing each other in time. The unique natural geosystem existing in Eastern Europe in the Late Permian is named the East European Placket. This study is destined for the general paleontological public and experts in primitive tetrapods and continental deposits of the Late Paleozoic.