CRETACEOUS VERTEBRATES FROM THE GUSINOE-LAKE BASIN IN TRANSBAlKALIA AND THEIR CONTRIBUTION INTO AGE DETERMINATION AND RECONSTRUCION OF DEPOSITION ENVIRONMENT

New sites with the remains of the Late Barremian – Middle Aptian dinosaurs and other vertebrates were found in the northof the Gusinoe-Lake Basin. The sites with the same remains identitied earlier were also explored in detail. The assemblage includes sauropods cf. Chiayasaurussp., large theropods (“carnosaurs”), small ornithomimid theropod dinosaurs, armatosaurs (Ankylosauria ?), champsosaurs Khurendukhosaurus sp., turtles (Kirgizemys dmitrievi, etc.), small birds, relatively large teleosts, holosteans, acipenseriform Stichopterus. This assemblage existed earlier than that of Late Aptian age, including small teleosts Lycoptera. The latter one existed apparently during the ingressions of brackish liman waters into inland reservoirs. The age of assemblages was determined through correlating fauna remains with those from Middle Asia and Mongolia, using a climatic-stratigraphic scale, and the data on sequence of ingressions and regressions. Geologic section of the Gusinoe-Lake Basin plays a key role in determining the sequence as well as the age of deposits, and ages of a series of Early Cretaceous vertebrate assemblages from Transbaikalia, Mongolia, and China.