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Ediacaran microfossils from the Ura Formation, Baikal-Patom Uplift, Siberia: taxonomy and biostratigraphic significance

Published online by Cambridge University Press:  14 July 2015

Vladimir N. Sergeev ,
Andrew H. Knoll  and
Natalya G. Vorob'Eva
Vladimir N. Sergeev
Affiliation:
1Geological Institute, Russian Academy of Sciences, Pyzhevskii per., 7, Moscow, 119017, Russia, ;
Andrew H. Knoll
Affiliation:
2Department of Organismic and Evolutionary Biology, Harvard University, 26 Oxford Street, Cambridge, MA 02138, USA,
Natalya G. Vorob'Eva
Affiliation:
1Geological Institute, Russian Academy of Sciences, Pyzhevskii per., 7, Moscow, 119017, Russia, ;
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Abstract

Abundant and diverse microfossils from shales of the uppermost Ura Formation, central Siberia, document early to middle Ediacaran life along the southeastern margin of the Siberian Platform. The Ura Formation is well exposed in a series of sections in the Lena River basin but the best microfossil assemblages come from a locality along the Ura River. Here, the uppermost twenty meters of the formation contain diverse microfossils exceptionally well preserved as organic compressions. Fossils include nearly two dozen morphospecies of large acanthomorphic microfossils attributable to the Ediacaran Complex Acanthomorph Palynoflora (ECAP), a distinctive assemblage known elsewhere only from lower, but not lowermost, to middle Ediacaran rocks. Discovery of ECAP in strata previously considered Mesoproterozoic through Cryogenian confirms inferences from chemostratigraphy, dramatically changing stratigraphic interpretation of sedimentary successions and Proterozoic tectonics on the Siberian Platform. Systematic paleontology is reported for 36 taxa (five described informally) assigned to 23 genera of both eukaryotic and prokaryotic microfossils. One new genus and two new species are proposed: Ancorosphaeridium magnum n. gen. n. sp. and A. minor n. gen. n. sp.

Type
Research Article
Information
Journal of Paleontology , Volume 85 , Issue 5 , September 2011 , pp. 987 - 1011
Copyright
Copyright © The Paleontological Society 

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