No abstract

The taxonomic diversity of the rugose corals following the mid-Carboniferous ‘lesser mass extinction event’ (Alekseev 1989) may be subdivided into two intervals. The survival interval includes long-ranging survivors, short-ranging survivors ( Dibunophyllum, Palaeosmilia, Diphyphyllum ), survivors with post-crisis ontogenetic changes ( Caninia, Bothrophyllum ), newly-appeared taxa with hypothetical ancestors ( Profischerina, Protodurhamina ) and those of cryptogenic origin ( Lytvophyllum ). The lower limit of the survival interval coincides with the Eumorphoceras/Homoceras Zone and can be identified in the Donetz Basin, Gornaya Bashkiria, Novaya Zemlja, North Timan, Cantabrian Mountains (Rodriguez et al. 1986) and the Western Interior of the USA (Sando 1989). The recovery interval is established by the appearance of the immigrant genus Petalaxis and by increasing specific diversity in pre-existing lineages. Its lower limit corresponds to the Pseudostaffella praegorsky—Profusulinella staffelliformis boundary, the lower boundary of the Westphalian A in the Cantabrian Mountains and the lower boundary of the Atokan Series in the Western Interior of the USA. The radiation interval was marked by the appearance of astreoid colonies in the Petalaxis—Ivanovia lineage at the Fusulinella calaniae—F. vozhgalensis—F. kamensis lower boundary.

Several existing schemes for Carboniferous stratigraphy officially adopted in regions of the Russian Federation are summarized and discussed. These regions with different geological histories and distinct depositional settings include the Moscow Basin, the Urals, North Timan, Siberia, the Kuznetsk Basin, the Mongol-Okhotsk Region, and the Verkhoyansk-Okhotsk Region, and Kolyma-Omolon Region. Region. Broad correlations based on macro- and microfossils are possible between the regions, while all regional schemes are correlated to the official Russian General Stratigraphic Scheme for the Carboniferous, using zonations based on orthostratigraphic fossils. The Russian General Stratigraphic Scheme is correlated to the International Stratigraphic Scale using ammonoids, conodonts, foraminifers and palynomorphs.

No abstract