Development of palynoflora throughout the Late Cretaceous and Paleocene in the Amur River region

Valentina MARKEVICH & Eugenia BUGDAEVA
Institute of Biology & Soil Science FEB RAS, Vladivostok, Russia

The Santonian palynoflora of the Zeya-Bureya Basin was dominated by cyatheaceous and dicksoniaceous ferns, and taxodialeans. Gymnosperms are mainly represented by Ginkgocycadophytus and the Pinaceae and Taxodiaceae; angiosperms - by Juglandaceae. In the Campanian palynoflora Cyatheaceae and Polypodiaceae prevail; among gymnosperms - conifers; angiosperms are represented by the Platanaceae, Fagaceae, and Juglandaceae. Triprojectate pollen is rare. The angiosperms are numerous in the early Maastrichtian palynoflora. The diversity of triprojectate pollen increases. Among gymnosperms, the Pinaceae and Taxodiaceae dominate. The middle Maastrichtian palynoflora is dominated by gymnosperms (Pinaceae, Taxodiaceae, and Ginkgocycadophytus); among angiosperms the Betulaceae, Juglandaceae, Fagaceae, Ulmaceae, and Myricaceae prevail. The late Maastrichtian palynoflora is dominated by the Taxodiaceae and Ulmaceae; among ferns the polypodiaceous spores are abundant; the angiosperms are rather diversified and are represented by pollen having affinity with the Betulaceae, Salicaceae, Juglandaceae, Myricaceae and Myrtaceae. The diversity of triprojectate pollen also increases. Floral changes were gradual across the boundary between the Mesozoic and Cenozoic eras. Only some Cretaceous palynotaxa disappear; the structure of dominance changes, but composition of the palynoflora mostly remains invariable. The early Danian palynoflora is dominated by ferns (Polypodiaceae) and gymnosperms (Taxodiaceae, Cupressaceae, and Pinaceae); and among angiosperms, the Juglandaceae and Fagaceae dominate. The triprojectate pollen is rare, and its taxonomical diversity decreases. This research was supported by the Russian Academy of Sciences (grant 12-I-28-01), Russian Foundation for Basic Research (grant 12-04-01335), Far East Branch of RAS (grant 12-III--06-075, 12-III--06-070).

2012 Organizing Committee