The First Data on Middle Jurassic Dinoflagellate Cysts and Foraminifera of the Russian Far East

The first records of dinocysts and foraminifers in the Middle Jurassic deposits of the Russian Far East and their taxonomic affiliation are reported. The use of foraminiferal and ostracod assemblages as a tool for biostratigraphic subdivision and correlation of the Middle Jurassic sections of this region is very difficult due to the poor preservation and limited occurrence of these microfossils. Findings of the dinocysts Endoscrinium galeritum, Tubotuberella cf. apatela, Wanaea fimbriata, and Meiourogonyaulax cf. caytonensis raise the question of correcting the stratigraphic range of the lithological formations recognized in the Middle Jurassic.