Late Cretaceous Flora of the Zyrianka Coal Basin, North-Eastern Russia: Composition, Age and Plant Communities
Plant fossils collected by O.V. Grinenko in 1989 in the Zyrianka Coal Basin (North-Eastern Russia) on the right bank of Vstrechnaya River were studied. Vstrechnaya flora comprises 25 species of fossil plants belonging to ferns, cycadaleans, ginkgoaleans, leptostrobaleans, conifers, gymnosperms of an uncertain systematic affinity and angiosperms. Vstrechnaya taphoflora is dated to the Late Cretaceous, most probably Turonian and Coniacian, due to the presence of advanced taxa of conifers and angiosperms in it. A significant difference of the Vstrechnaya floristic assemblage, as well as of the entire flora of the same name, from the flora of the Buor-Kemus formation allows us to suggest that the plant-bearing deposits constitute an independent local stratigraphic unit named Vstrechnaya formation. Vstrechnaya taphoflora comprises plants that probably formed individual Mesophytic and Cenophytic plant communities. The composition of the former was inherited from more ancient Early Cretaceous regional floras whereas the latter revealing advanced taxa of conifers and angiosperms reflects a gradual invasion of an evolutionary new Late Cretaceous vegetation to the continental interior of North-Eastern Asia.