Microfossils and Rb-Sr age of glauconite in the key section of the Upper Proterozoic of the northeastern part of the Russian plate (Keltmen-1 borehole)

Palaeobiology of latest Ediacaran phosphorites from the upper Khesen Formation, Khuvsgul Group, northern Mongolia

“…A latest Ediacaran age for the Khesen fossils provides support for the extension of the stratigraphic range of Appendisphaera tenuis into the last few million years of the Ediacaran Period (e.g., Golubkova et al 2015), and for the extension of Cavaspina basiconica beyond Given that the Khesen assemblage is latest Ediacaran in age, we might expect similarities between it and the assemblage from the East European Platform described by Golubkova et al (2015). The absence of Cavaspina, Megasphaera and Variomargosphaeridium from the East European Platform could be accounted for by different styles of fossilization.…”

“…The Doushantuo Formation, particularly where it is exposed at Weng'an, yields the highest diversity of eukaryotic fossils known from the first ~4 billion years of Earth history (Liu et al 2014;Xiao et al 2014b;. Dominant are large (commonly >100 µm) acanthomorphic acritarchs (Doushantuo-Pertatataka-type) which offer a potential biostratigraphic framework for Ediacaran successions (Xiao et al 2016): similar fossils are known from shales and early diagenetic cherts in Australia (Grey 2005;Willman et al 2006;Willman 2007;Willman & Moczydłowska 2008, eastern Europe (Vorob'eva et al 2009a;Golubkova et al 2015), India (Shukla & Tiwari 2014;Joshi & Tiwari 2016), Siberia (Moczydłowska et al 1993;Sergeev et al 2011;Moczydłowska & Nagovitsin 2012), and Svalbard (Knoll 1992). Some of the fossils show early examples of multicellularity and they may represent animal embryos or resting cysts (Xiao et al 1998;Xiao & Knoll 2000;Hagadorn et al 2006;Yin et al 2007;Chen et al 2009b;Cohen et al 2009;Yin et al 2013;Chen et al 2014;Xiao et al 2014a), in which case the Doushantuo fossils are the oldest body fossils of animals known from the geological record.…”

Acanthomorphic acritarchs of the Doushantuo Formation from an upper slope section in northwestern Hunan Province, South China, with implications for early–middle Ediacaran biostratigraphy

“…These divergent correlations make it difficult to resolve the stratigraphic relationship between DPAs and Ediacara-type macrofossils, thus complicating our efforts to sequence Ediacaran evolutionary, climatic, and geochemical events . However, there are increasing evidence suggesting that elements of the Ediacara biota may range downward to the lower Ediacaran System (Macdonald et al, 2013;Xiao et al, 2013) and some DPA taxa may range upward above the level of Shuram excursion (Golubkova et al, 2015; this study). DPAs and Ediacara-type macrofossils may have overlapping stratigraphic ranges, regardless how the carbon isotope excursions are correlated with Gaskiers glaciation.…”

“…Currently available data from South China suggest that at least in the Yangtze Gorges area, DPAs appeared shortly after the termination of the Marinoan global glaciation , and disappeared at the horizon yielding a prominent carbon isotopic anomaly (EN3, likely equivalent to the Shuram excursion) in the middle Ediacaran Period (Liu et al, 2014a;Narbonne et al, 2012;Xiao et al, 2016), which represents one of the most pronounced negative carbon isotopic excursions in Earth history (Grotzinger et al, 2011) and has been considered as a potential chemostratigraphic tool for Ediacaran subdivision and global correlation . However, biostratigraphic data from Russian Plate hint that DPAs may extend above the Shuram-equivalent horizon (Golubkova et al, 2015). Therefore, it is important to document the full stratigraphic range of DPAs in the Yangtze Block of South China in order to test whether DPAs extend above the Shuram excursion.…”

Russia–UK Collaboration in Paleontology: Past, Present, and Future

“…Nonetheless there is a substantial record of microscopic organic fossils in the Precambrian of Russia which is too extensive to summarize here: Archean and Proterozoic examples are treated in reviews of global occurrences by Knoll and Sergeev (1995) and Sergeev et al (2007Sergeev et al ( , 2010 and important new discoveries continue to be made (e.g. Golubkova et al 2015). The first large organisms, which are likewise non-biomineralized, became widespread during the Ediacaran Period.…”