Editing Ediacaran (section)

==Ediacaran vs. Vendian==
{{See also|Riphean (stage)|Jotnian}}
The Ediacaran Period overlaps but is shorter than the '''Vendian''' Period (650 to 543 million years ago), a name that was earlier, in 1952, proposed by Russian geologist and [[paleontologist]] [[Boris Sergeyevich Sokolov|Boris Sokolov]]. The Vendian concept was formed stratigraphically top-down, and the lower boundary of the Cambrian became the upper boundary of the Vendian.<ref name= Sokolov1952>{{cite journal
 | author = B. M. Sokolov
 | year = 1952
 | title = On the age of the old sedimentary cover of the Russian Platform
 | journal = Izvestiya Akademii Nauk SSSR, Seriya Eologicheskaya
 | volume = 5
 | pages = 21–31
}}</ref><ref name="Sokolov1997">Sokolov, B.S. (1997). "Essays on the Advent of the Vendian System." 153 pp. [[KMK Scientific Press]], Moscow. (in Russian)</ref>

Paleontological substantiation of this boundary was worked out separately for the [[siliciclastic]] basin (base of the [[Baltic Sea|Baltic]] Stage of the [[East European craton|Eastern European Platform]]<ref name=Sokolov1965>Sokolov B. S. (1965) "Abstracts of All-Union Symposium on Paleontology of the Precambrian and Early Cambrian." Nauka, Novosibirsk.</ref>) and for the [[carbonate]] basin (base of the [[Tommotian]] stage of the [[Siberian Platform]]).<ref name=Rozanov1969>{{cite journal
 |author1=Rozanov, A.Y. |author2=Missarzhevskij, V.V. |author3=Volkova, N.A. |author4=Voronova, L.G. |author5=Krylov, I.N. |author6=Keller, B.M. |author7=Korolyuk, I.K. |author8=Lendzion, K. |author9=Michniak, R. |author10=Pykhova, N.G. |author11= Sidorov, A.D. |name-list-style=amp| year = 1969
 | title = The Tommotian Stage and the problem of the lower boundary of the Cambrian
 | journal = Trudy Geologičeskogo Instituta AN SSSR
 | volume = 206
 | pages = 1–380
}}</ref>
The lower boundary of the Vendian was suggested to be defined at the base of the [[Varanger Peninsula|Varanger]] (Laplandian [[Stage (stratigraphy)|stage]]) [[tillite]]s.<ref name= Sokolov1997/><ref name=Fedonkin2007>{{cite web |url=http://vendian.net76.net/Vendian_vs_Ediacaran.htm |title=Vendian versus Ediacaran: priorities, contents, prospectives |author1=M. A. Fedonkin |author2=B. S. Sokolov |author3=M. A. Semikhatov |author4=N. M. Chumakov |year=2007 |url-status=dead |archive-url=https://web.archive.org/web/20111004184527/http://vendian.net76.net/Vendian_vs_Ediacaran.htm |archive-date=October 4, 2011 }} In: {{cite web |url=http://www.geosci.monash.edu.au/precsite/docs/workshop/moscow07/transaction.pdf |title=The Rise and Fall of the Vendian (Ediacaran) Biota |date=August 20–31, 2007 |work=Origin of the Modern Biosphere. Transactions of the International Conference on the IGCP Project 493n Moscow: GEOS |archive-url=https://web.archive.org/web/20121122062305/http://www.geosci.monash.edu.au/precsite/docs/workshop/moscow07/transaction.pdf |archive-date=22 November 2012 |url-status=dead }} (82mb)</ref>

The Vendian in its type area consists of large subdivisions such as Laplandian, [[Redkino]], [[Kotlin Island|Kotlin]] and [[Rovno]] regional stages with the globally traceable subdivisions and their boundaries, including its lower one.

The Redkino, Kotlin and Rovno regional stages have been substantiated in the type area of the Vendian on the basis of the abundant organic-walled [[microfossil]]s, megascopic algae, [[metazoan]] body fossils and [[ichnofossil]]s.<ref name=Sokolov1997/><ref name=SokolovFedonkin1984>{{Cite journal| doi = 10.1134/S0869593808060014| title = The Yudomian of Siberia, Vendian and Ediacaran systems of the International stratigraphic scale| year = 2008| last1 = Khomentovsky | first1 = V. V.| journal = Stratigraphy and Geological Correlation| volume = 16| issue = 6| pages = 581–598 |bibcode = 2008SGC....16..581K | s2cid = 128966206}}</ref>

The lower boundary of the Vendian could have a [[biostratigraphic]] substantiation as well taking into consideration the worldwide occurrence of the Pertatataka assemblage of giant acanthomorph [[acritarch]]s.<ref name=Fedonkin2007/>