The first Jurassic palynofloral assemblage from Japan is reported from the Oxfordian Tochikubo Formation of the Soma-Nakamura Group, Fukushima Prefecture. Palynomorphs are quite diversified, with 32 genera and 41 species of lycopod and fern spores, gymnosperm pollen and freshwater algae. The composition of the assemblage is consistent with the Oxfordian age of this nonmarine formation and confirms a fluvio-lacustrine paleoenvironment, further detailing the paleovegetation reconstructed from macrofloral remains. Previous palynofloral reports of eastern Asia are reviewed and indicate that northeast Japan shares most similarities with coeval paleofloras of southeastern Russia. Consequences for paleofloristic provincialism and climates of the region during the Late Jurassic are discussed.

据报道，日本最早的侏罗纪古植物组合来自福岛县相马-中村集团的牛津筑波群。食苔藓植物种类繁多，有32属和41种番茄科和蕨类孢子，裸子植物花粉和淡水藻类。该组合的组成与该非海洋构造的牛津时代相符，并证实了氟湖相的古环境，进一步详细说明了由大花残骸重建的古植被。回顾了以前东亚地区的植物区系报告，并指出日本东北部与俄罗斯东南部的古代古植物具有最大的相似性。讨论了侏罗纪晚期古植物区系化和该地区气候的后果。