pdf: http://rogov.zwz.ru/meledina%20et%20al,2010_exoticus_zone_en.pdf

The stratigraphic position of the Praechetaites exoticus Zone in the Volgian Stage is discussed in the context of published suggestions to place this unit in the middle Volgian Substage. Recently Rogov and Zakharov on the base of new data from the Russian Platform and Nordvik section (N. Siberia) suggested Middle Volgian age of this zone (see Zakharov, Rogov, 2008; Rogov, Zakharov, 2009; Rogov, 2010). Our Siberian colleagues are disagreed with this proposal, in their opinion position of the Exoticus Zone still unclear. They also suggesting that this zone cannot be recognized in Nordvik section and that such zone as it has been firstly recognized in its type area characterized by Praechetaites only, while other ammonites (such as Laugeites) should be absent here. In our opinion all three points emphasized by our Siberian colleagues are erroneous. Our reply to their criticism will be published at the 1st volume of the same journal in the year 2011.