The study of a core of borehole 8 drilled in the town of Maloyaroslavets to a depth of 94 m has made it possible to obtain the biostratigraphic characteristics of the Tarusian and Protvian regional substages of the Serpukhovian Stage and lower part of the Vereian Regional Substage of the Moscovian Stage based on foraminifers and conodonts. The Tarusian Regional Substage is attributed to the Neoarchaediscus postrugosus Zone. The Eostaffellina paraprotvae Zone has been established in the Protvian Regional Substage, and a deep-water conodont assemblage of the Gnathodus bollandensis Zone has been found in its upper part (6.8–12.0 m above the base). The generalization of all data on conodonts of the Protvian Regional Substage of the Moscow Syneclise has shown that it contains at least four transgressive–regressive cyclites. The type locality of the species Eostaffellina protvaeensis has been specified in the Tetyuevo section in the Rzhev Volga region. A rich assemblage of conodonts from the Vereian Alyutovo Formation of the Moscovian Stage belongs to the Declinognathodus donetzianus Zone.

The morphology of the type genus Planoendothyra Reitlinger, in: Rauser-Chernousova et Fursenko, 1959, family Endothyridae, Brady, 1854, and of some species previously described among the five groups of species of the genus Endothyra identified by Reitlinger (1950, p. 30), based on the shell morphology, from the Middle Carboniferous deposits in the central part of the Russian Platform. The validity of the originally morphological genus Planoendothyra and its first appearance in the Upper Visean–Serpukhovian interval of the Lower Carboniferous are confirmed. The species Planoendothyra aljutovica (Reitlinger), P. minuta (Reitlinger), P. mosquensis (Reitlinger), P. rzhevica (Reitlinger), P. siviniensis (Reitlinger), P. irinae (Reitlinger), P. spirilliniformis (Brazhnikova, Potievskaya) described again and translated (hic) into the composition of the genus Planoendothyra . The species composition of the genus for the Upper Visean–Serpukhov interval of the Lower Carboniferous has been emended. Three groups of species are recognized based on the type of supplementary deposits in the shell. The phylogeny of the genus Planoendothyra Reitlinger, 1959 is discussed.

This paper reviews the foraminiferal biostratigraphy of the Devonian–Carboniferous (D–C) boundary beds in Russia and Western Kazakhstan. The regional records of the zonal successions of Russia are summarised from sections and boreholes of the Volga-Urals Subregion of the East European Platform (Syzran no. 401 Borehole, Melekesskaya no.1 Borehole); Timan-Pechora Province of the East European Platform (Kamenka Section); South Urals (Sikaza, Zigan, Ryauzyak and Dzerzhinka sections); Middle Urals (Pershino Section); and West Siberia, Vagai-Ishim Basin (Borehole no. 1 Kurgan-Uspenskaya), and the zonal successions of Western Kazakhstan are summarised from the Mugodzhary Mountains. Three foraminiferal biozones can be defined in the interval comprising the latest Devonian and earliest Carboniferous: Quasiendothyra kobeitusana Zone, the Tournayellina pseudobeata – remnant Quasiendothyra Zone, and the Earlandia minima Zone. The D–C boundary interval is situated within the Tournayellina pseudobeata –remnant Quasiendothyra Zone. A correlation with the ammonoid and conodont zonations is proposed, which is useful for correlating deep-water and shallow-water successions.

The foraminiferal genus Janischewskina of the family Janischewskinidae Reitlinger, 1996, which is widespread in Eurasia and plays an important role in stratigraphy of the Upper Viséan-Serpukhovian interval of the Lower Carboniferous (=Mississippian), is revised. The morphological characteristics of the genus and species were clarified and supplemented, details of the structure of the interseptal space and sutural apertures are clarified, and the stratigraphic and geographical distribution of the species is documented. A new foraminiferal species J. adtarusia Gibshman, Zaytseva and Stepanova, sp. nov. is described.

This paper aims to evaluate potential biostratigraphic markers for the Viséan–Serpukhovian boundary in sections of Europe and Asia, to help identify the base of the global Serpukhovian Stage, which is a high priority task for Carboniferous biostratigraphy. Sections in the Serpukhovian stratotype area in the Moscow Basin contain a gap at the base of the Tarusian Regional Substage (basal in the classical Serpukhovian), so the traditional boundary defined in these sections cannot be precisely correlated with other successions worldwide. The IUGS Task Group to establish a GSSP close to the traditional Viséan–Serpukhovian boundary focused on the search for a new boundary marker, primarily on the first appearance datum (FAD) of the conodont Lochriea ziegleri in the lineage Lochriea nodosa to Lochriea ziegleri, considering it to be a suitable biostratigraphic event. The FOD (first occurrence datum) of L. ziegleri has been recognized in many successions worldwide, although only in a few sections the supposed evolutionary lineage of L. ziegleri was inferred. There are serious impediments to the FAD of L. ziegleri being universally accepted as the boundary marker. This paper presents a review of the FOD levels of L. ziegleri documented so far from multiple sections along with other correlatable markers (foraminifers and ammonoids) that can serve as additional points of reference in sections where a conodont record is poor or absent. The reviewed sections are Naqing Section (South China), Verkhnyaya Kardailovka and Kugarchi sections (South Urals, Russia), Mariinsky Log and Ladeinaya Mountain Sections (western slope of the Middle Urals, Russia), Novogurovsky Section (Moscow Basin, Russia), Vegas de Sotres Section (Cantabrian Mountains, Spain), Lugasnaghta Section (County Leitrim, Ireland), Wenne River Bank Section (Germany), and Milivojevića Kamenjar Section (Družetić, NW Serbia). We also included a compilation of data from sections of North England and southern Scotland. In this paper, we will mainly focus on newly described sections, while the discussion of most previously described sections was summarized by Nikolaeva et al. (2001, 2002, 2005, 2009b) and other publications, so they are only briefly mentioned in this review. It should be added that there is no such a thing as a perfect GSSP section, as each section has certain disadvantages, either lithological, paleontological, or both, so it is important to hear and discuss all the different opinions to develop the optimum strategy for future research. In addition, we analyze published records from several sites in North England and southern Scotland. We discuss the first appearances of the ammonoid genera Cravenoceras, Edmooroceras, Lyrogoniatites, Dombarites, and Platygoniatites, the foraminifers Neoarchaediscus postrugosus, Hemidiscopsis muradymica, H. hemisphaerica, species of Janischewskina and Monotaxinoides, Eostaffella pseudostruvei group, Eostaffellina decurta, and Endothyranopsis plana. We publish here for the first time the useful accounts of foraminifers and conodonts from the Mariinsky Log Section and Ladeinaya Mountain Section (Middle Urals, Russia), and re-figure several important type specimens from Europe and the Urals.

Biostratigraphy, taxonomy, morphology and evolution of foraminifers Loeblichia paraammonoides, L. ukrainica, L. minima and Cepekia cepeki, potential markers for the base of the Serpukhovian and the boundaries of the Serpukhovian regional substages of the East European Platform, are discussed.

A review of the proposed markers for the base of the Serpukhovian has shown that their entries are not consistent in different sections, especially when they are not controlled by other fossil groups. The diagnosis and interspecific relations in the genus Lochriea of the conodont species L. ziegleri, the primary candidate marker, needs to be reassessed and it needs to be decided which morphotype is the best marker. The first occurrence levels of the marker foraminiferal species, especially J. delicata and N. postrugosus, need to be agreed, and the taxa from the critical levels need to be illustrated before a decision can be made on the boundary choice.

New data on the taxonomic composition of the algal flora of the Late Viséan of the Moscow Basin are discussed based on newly collected material. The algal assemblage comprises 24 taxa, 14 taxa identified to species, nine identified to genus, and one taxon not positively identified. Representatives of the genera Anthracoporella , Anthracoporellopsis , Asphaltina , Asphaltinella , Asteroaoujgalia , and Zidella are recorded for the first time from the Upper Viséan of the Moscow Basin. The large geographic ranges of these benthic calcareous algae suggest a relatively free exchange of the floral elements of the Late Viséan Moscow Basin with the remote basins of North America and the Paleotethys in the Aleksinian and Mikhailovian time. The new data fill an important gap in the current state of knowledge of Late Viséan marine algae.

The upper Viséan–Serpukhovian strata in the type region for the Serpukhovian Stage is an epeiric‐sea succession ca. 90 m in thickness. The predominantly Viséan Oka Group (comprising the Aleksin, Mikhailov, and Venev formations) is dominated by photozoan packstones with fluvial siliciclastic wedges developed from the west. The Lower Serpukhovian Zaborie Group is composed of the Tarusa and Gurovo formations. The latter is a new name for the shale‐dominated unit of Steshevian Substage age in the studied area. The Zaborie Group is composed of limestones and marls in its lower (Tarusa and basal Gurovo) part and black smectitic to grey palygorskitic shales in the main part of the Gurovo Formation. The Gurovo Formation is capped by a thin limestone with oncoids and a palygorskitic–calcretic palaeosol. The Upper Serpukhovian is composed of a thin (3–12 m) Protva Limestone heavily karstified during a mid‐Carboniferous lowstand. The succession shows a number of unusual sedimentary features, such as a lack of high‐energy facies, shallow‐subtidal marine sediments penetrated by Stigmaria, the inferred atidal to microtidal regime, and palustrine beds composed of saponitic marls. The succession contains many subaerial disconformities characterized by profiles ranging from undercoal solution horizons to palaeokarsts. Incised fluvial channels are reported at two stratigraphic levels to the west of the study area. The deepest incisions developed from the Kholm Disconformity (top of the Mikhailov Formation). This disconformity also exhibits the deepest palaeokarst profile and represents the major hiatus in the Oka–Zaborie succession. The new sea‐level curve presented herein shows two major cycles separated by the Kholm Unconformity at the Mikhailov/Venev boundary. The Lower Serpukhovian transgression moved the base‐level away from falling below the seafloor so that the section becomes conformable above the Forino Disconformity (lower Tarusa). The maximum deepening is interpreted to occur in the lower dark‐shale part of the Gurovo Formation. The base of the Serpukhovian Stage is defined by FADs of the conodont Lochriea ziegleri and the foraminifer Janischewskina delicata in the middle of the sequence VN2. The Aleksinian–Mikhailovian interval is provisionally correlated with the Asbian (Lower–Middle Warnantian) in Western Europe. Based on FODs of Janischewskina typica and first representatives of Climacammina, the Venevian is correlated with the Brigantian in Western Europe. The Tarusian–Protvian interval contains diverse fusulinid and conodont assemblages, but few forms suitable for international correlation. FADs of the zonal conodont species Adetognathus unicornis and Gnathodus bollandensis at several metres above the Protvian base suggest correlation of the entire Zaborie Group and may be the basal Protvian to the Pendleian. Copyright © 2014 John Wiley & Sons, Ltd.