A new assemblage of Early Vendian (Middle Ediacaran) microfossils, including acanthomorphic acritarchs and various filamentous remains, as well as sphaeromorphic striated vesicles of Valeria, which are not characteristic of deposits of this age, is described from the Ura Formation of the Dal’nyaya Taiga Group of the Patom Basin. A new species of acanthomorphs Hocosphaeridium crispum sp. nov. is recognised. The Ediacaran eukaryotic phytoplankton taphocoenoses are shown to be selectively restricted to the open-sea proximal facies of the inner ramp.

The results of U–Th–Pb (LA-ICP-MS) geochronological studies of detrital zircon and Sm–Nd isotopic studies of metaterrigenous rocks of the Udokan Complex of the Nizhnekhani graben-syncline in the western part of the Aldan Shield are discussed. On the basis of the data obtained, it was found that the accumulation of terrigenous deposits of the Nizhnekhani graben-syncline occurred after 2.65 and up to 1.9 Ga, probably at the Paleoproterozoic stage of the development of the region. The igneous and metamorphic rocks formed at ca. 2.65, 2.71, 2.82–2.86, 2.99, 3.10–3.21, and probably 3.26–3.42 Ga within the Chara–Olekma Geoblock, its junction zone with the West Aldan Megablock, and the Kurulta Block of the Stanovoi suture zone were the sources of detrital material. Metaterrigenous rocks of the Nizhnekhani graben-syncline were formed from crustal sources with the Paleo- and Mesoarchean Nd model ages, while a significant contribution of the Paleoproterozoic juvenile material was established for the metasedimentary rocks of the Kodar–Udokan Trough. Significant differences in the age and Nd isotopic characteristics of sources of terrigenous deposit of the Nizhnekhani graben-syncline and the Kodar–Udokan Trough suggest that they accumulated in isolated basins.