The New Genus Amurodendron (Cupressaceae s.l.) from the Paleocene Boguchan Flora of the Amur Region (Russian Far East)

The new genus Amurodendron with the type species Amurodendronpilosum sp. nov. is described from the Paleocene of the Amur Region (Russian Far East) based on compressions of vegetative shoots and leafy shoots with pollen cones and in situ pollen grains. Leaves are polymorphic. Linear-lanceolate leaves are helically arranged, sometimes distichous, with petiolate long-decurrent bases. The most characteristic feature of the new taxon is the presence of numerous hair-like marginal teeth observed on the linear leaves from leaf base to apex and also on the axis of shoots. Rhomboid scale-like leaves borne at the bases of vegetative shoots and on the axes bearing pollen cones. All leaves are amphistomatic. Stomata of leaves and lower microsporophylls are monocyclic or incompletely amphicyclic and predominantly longitudinally oriented. Pollen cones are ellipsoidal, terminally and laterally arranged; lateral cones arrange alternately or subopposite. Pollen grains are small to medium in size, rounded, with distal papilla, granular ectexine and lamellate endexine. The combination of features of Amurodendronpilosum is indicative of Cupressaceae but distinguishes it from any known extant and fossil conifers of the family.