My first post on Russia I bumped into Barry Sutton on the net and found him and his sites to be a wealth of knowledge and down right interesting. Here is his website on Russia and its fossils-
This website is presented to showcase Carboniferous fossils of the
Moscow region of Russia; an area that is world famous for beautifully
preserved fossils. This website provides an opportunity to see fossils
of those deposits that are poorly known outside Russia or have not
been illustrated with high quality photos. Some of the Late Carboniferous
(Pennsylvanian) fossils occur in both the Moscow region and in the
The fossils shown here are grouped by geologic stage, illustrated on
the chart below. This shows the international stages of the Carboniferous
and the regional stages for Russia, west Europe and North America.
Gigantoproductus crassus Sarytcheva – brachiopod – Mississippian – Visean Stage
Check out his site as its a very interesting read!