This special issue is the third and last of the série published by Geodiversitas within the framework of the International Peri-Tethys Programme. It is devoted to the data obtained by the Russian scientists involved in the Programme. The collaborations established with the colleagues of the Indépendant States Community account for one of the original and main contributions of the Programme. Indeed, they allowed exchanges of informations and methods. Some results are published as stratigraphie correlations papers in the special volumes published by the Programme (Geodiversitas and Mémoires du Muséum national d'Histoire naturelle). Some others appear on the palaeogeographic maps (Peri-Tethys Atlas will be published in 2000) which synthétise and illustrate this fruitful cooperation. In order to present an homogeneous set which corresponds to the quality requests of the Museum publication team, all the figures were redrawn or picked again by the editors. We thank for her help for this work E. Cambreleng (laboratoire de Géologie MNHN). We are indebted to the Museum national d'Histoire naturelle for his contribution in the concrétisation of the collaboration with our Russian colleagues. Finally, we would like to express our friendly gratitude to Hervé Lelièvre, Editor in Chief, and Florence Kerdoncuff, assistant editor, for their competence and professionalism. This volume fits in the série of Peri-Tethys International Programme publications.