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This paper presents a description of the Olenekian–Anisian sections in South Primorye, Far East Russia, containing reptile remains. The paper describes important ammonoid Flexoptychites cf. rifunus (Yabe et Shimizu), as well as Flexoptychites cf. compressus (Yabe et Shimizu), which are stratigraphically significant. New Anisian reptile remains were discovered from four stratigraphic levels in South Primorye: (1) the upper part of the middle Anisian Acrochordiceraskiparisovae Zone (Ichthyopterigia indet. A), (2) the middle part of the upper Anisian Flexoptychites cf. rifunus Beds (Reptilia indet. cf. Ichthyopterygia A), (3) the upper part of the upper Anisian Flexoptychites cf. rifunus Beds (Ichthyoterygia indet. B), and (4) the uppermost part of the upper Anisian Flexoptychites cf. rifunus Beds (Reptilia indet. cf. Ichthyopterygia B). The Anisian stage is marked by an abundance of medium- to large-sized ichthyopterygians and a comparatively limited number of gigantic forms, particularly in the eastern Panthalassic and western Tethyan provinces. Our recent discovery has unveiled the presence of medium- to large-sized reptiles, seemingly ichthyopterygians, in the western Panthalassic province during the late Anisian (Flexoptychites cf. rifunus Chrone). [ABSTRACT FROM AUTHOR]

Brachiopods from the upper part of the Khalpirkian Regional Stage of the Tiryakh–Kobyume section of the Kobyume structural–facies zone in Southern Verkhoyanie have been studied. The collection is dominated by Strophalosia? vollossovitschi (Fredericks) and Cancrinella? sp. Single spiriferids are assigned to Crassispirifer monumentalis Abramov et Grigorjeva and Cr. aff. monumentalis Abramov et Grigorjeva, and, thus, host deposits are referred to the Crassispirifer monumentalis Beds. We found these beds earlier only in the lower part of the Khalpirkian Regional Stage. Reliable findings of the terminal brachiopod assemblage confined to the Khalpirkian of the Upper Permian have been reviewed. The assemblage is dominated by strophalosiids represented by Wyndhamia gijigensis (Zavodowsky), Marginalosia? magna Abramov et Grigorjeva, Subtaeniothaerus lungersgauzeni Solomina, and Strophalosia? aff. vollossovitschi (Fredericks). "Magadania" sp. and Cancrinella? sp. have been identified from linoproductids. Crassispirifer monumentalis spiriferids are an important element of the terminal assemblage. Athyridids of the Khalpirkian Regional Stage, known only in its lower part, are represented by Cleiothyridina nikolaevi Grunt, Cleiothyridina sp., and Bajtugania sp. The studied regional stage also contains findings of terebratulids attributed to Marinurnula? aff. mantuanensis (Campbell) and M.? aff. chivatschense (Zavodowsky). No brachiopods are known at the top of the Khalpirkian Regional Stage, while rhynchonellids Piarorhynchia sp. appear at the base of the Nekuchan Regional Stage. At the beginning of the Khalpirkian, the brachiopod community had an extended natural habitat in the shelf zone of the Verkhoyan Sea along the Angaraland coastline. Subsequently, this area was reduced and initially divided into two independent subareas confined to the East Kharaulakh and South Verkhoyan sectors. In the Late Khalpirkian, the brachiopod community was concentrated only in the Kobyume zone, where it ended up under the end-Permian mass extinction. Some taxa of the identified brachiopod assemblage have been traced in the Okhotsk region, the Ayan—Yuryakh anticlinorium, and the Omolon massif. [ABSTRACT FROM AUTHOR]

A vertical sequence of brachiopods was revealed at the base of the Verkhoyanian terrigenous complex of the Tit-Ary section in the northern part of the Tuora-Sis uplift of the lower reaches of the Lena River. As a result of the study of these brachiopods, it was established that in the indicated section, the Upper Cambrian dolomites are overlain by Gzhelian and Asselian deposits, characterized by brachiopods of the Jakutoproductus protoverkhoyanicus and Jakutoproductus verkhoyanicus biostratigraphic zones. This is the first proven fact of the presence of Upper Carboniferous deposits in the area. It is concluded that within the Tuora-Sis uplift from south to north, the upper age limit of the unconformity between the Cambrian and the Upper Paleozoic is growing older, while the base of the Verkhoyanian terrigenous complex is built up by the Permian basal beds and the Gzhelian deposits of the Upper Pennsylvanian. The Tit-Ary section is the first of those established in the lower reaches of the Lena River, with exposed boundary Carboniferous–Permian beds. [ABSTRACT FROM AUTHOR]

The latest Sandbian brachiopods and chitinozoans were studied in the Kõrgessaare and Haapsalu drill cores of Estonia. The brachiopod fauna shows a gradual renewal through the Keila Regional Stage (RS), differently from the rather persistent association of chitinozoans. An exception is the uppermost part of the stage, which differs in two sections in the taxonomic composition of chitinozoans and the occurrence of two species-level taxa of the Dalmanella kegelensis brachiopod group. D. kegelensis sensu lato has been considered an index taxon of the biozone in the Keila RS. It links the brachiopod faunas of North Estonia to those in NW Russia. In the latter region, the dolomitic and siliciclastic lagoonal and peritidal deposits overlying the strata with brachiopods of the D. kegelensis group are considered the youngest part of the Keila RS. [ABSTRACT FROM AUTHOR]

The earliest known Cyrtina in the Prague Basin has been discovered in the Kotýs Limestone of the Lochkov Formation (Lochkovian) among a rich brachiopod-coral fauna at Branžovy ridge near Bubovice (Beroun District, Czechia). Rare and imperfectly preserved silicified shells are assigned to Cyrtina praecedens Kozłovski, 1929, a species originally described from Podolia, Ukraine. The species is known also in north-eastern Russia (Tajmyr and Sette-Daban Mts) and likely also in New South Wales, Australia. Its distribution provides evidence of the rapid spread of Cyrtina across the shallow shelves of Laurussia, Siberia and Gondwana in the Early Devonian. The Devonian and Carboniferous distribution of Cyrtina is restricted to the agitated, shallow-water carbonate environment in tropical and temperate climatic belts. [ABSTRACT FROM AUTHOR]

Rare Oichnus simplex drill holes occur in mature obolid shells from the Cambrian/Ordovician boundary beds of northern Estonia (Iru and Ülgase) and the uppermost Cambrian of NW Russia (Lava River). The drill holes are significantly more common in the central rather than the marginal regions of the obolid valves. Drilling predators attacked Ungula ingrica in the Kallavere Formation and Ungula convexa in the Ladoga Formation. Failed predatory attacks on obolids were relatively common in the latest Cambrian-earliest Tremadocian of Estonia. Presumably drilling predators at Lava River and Iru differed from those at the Ülgase as indicated by significant differences in drill hole sizes at these locations. Most likely some types of worms preyed on obolids in the latest Cambrian-earliest Tremadocian of Estonia and latest Cambrian of NW Russia. The predation rate (6% to 9%) of studied obolids indicates that they likely had an epibenthic life mode. In addition to Oichnus drill holes in the obolids, there are also common pseudoborings caused by mineral dissolution. [ABSTRACT FROM AUTHOR]

Information on latest early Olenekian (latest Smithian) ammonoids is available apparently from only seven regions of the world, including South Primorye. Latest Smithian evidences on this topic are recorded from the West SMID (abbreviation from the Russian name of the quarry: "Building Materials and Details"), East SMID and Golyj Cape areas in South Primorye. This provides additional information on systematic composition of latest Smithian ammonoid, as well as conodont and brachiopod assemblages from the recently identified Shimanskyites shimanskyi Zone, located between lower Olenekian Anasibirites nevolini Zone and upper Olenekian Tirolites subcassianus Zone. There are many common ammonoid species in the Shimanskyites shimanskyi Zone and the underlying Anasibirites nevolini Zone, e.g., Prosphingitoides sp., Arctoceras septentrionale (Diener), Churkites syskoi Zakharov et Shigeta, Submeekoceras? subhhydaspis (Kiparisova), Prionites markevichi Zakharov et Smyshlyaeva, 'Anasibirites' simanenkoi Zakharov et Smyshlyaeva, Xenoceltites? subvariocostatus Zakharov et Smyshlyaeva, and Mianwaliites zimini Zakharov et Smyshlyaeva. The base of the Shimanskyites shimanskyi Zone, marked by a negative δ13Corg excursion in the Kamenushka-2 Section by our previous study, coincides with the FO (first occurrence) of ammonoids Shimanskyites shimanskyi Zakharov et Smyshlyaeva and Glyptophiceras cf. sinuatum (Waagen) and conodont Hindeodella budurovi Buryi. This zone is characterized additionally by some fossils common for the overlying upper Olenekian Tirolites subcassianus Zone: ammonoids of the genus Kamenushkaites, brachiopods Bittnerihyris margaritovi (Bittner) and Lepismatina sp. and conodont 'Neogondolella' (=?Borinella) jubata Sweet. The latest Smithian ammonoids recorded from the Shimanskyites shimanskyi Zone totally consist of 30 taxa belonging to 11 families (Sageceratidae, Ussuiriidae, Aspenitidae, Paranannitidae, Arctoceratidae, Proptychitidae, ?Galfetitidae, Prionitidae, ?Kashmiritidae, Xenoceltitidae and Palaeophyllitidae). The problems of global correlation of uppermost Smithian strata are also discussed. [ABSTRACT FROM AUTHOR]

As a result of study of new collections of brachiopods, a zonal scheme of the Asselian–Sakmarian deposits in the Verkhoyansk region based on the phylogenetic development of Jakutoproductus is elaborated. The J. verkhoyanicus Zone is distinguished in the Khorokytian Horizon; in some sections, it may be divided into the beds with J. talchanensis and beds with J. lenensis. The succession of the J. insignis, J. terechovi, and J. rugosus zones is established in the Echian Horizon and provides direct correlation with the Kolyma–Omolon region. The index species of all brachiopod zones of the Asselian–Sakmarian interval in the Verkhoyansk region are described: Jakutoproductus verkhoyanicus (Fredericks), J. insignis Abramov et Grigorjeva, J. terechovi Zavodowsky, and J. rugosus Ganelin. [ABSTRACT FROM AUTHOR]

The article presents the results of a study of Wenlock-Ludlow boundary sediments in the river Padimeytyvis basin at Chernov uplift using paleontological, lithological and chemostratic methods. The results of paleontological studies allowed attributing to the Wenlock the carbonate stratum of the upper part of the section along the stream Bezymjannyi and establishing Wenlock-Ludlow boundary only in the section of the river Padimeytyvis. The results of studying the isotope δ13Ccarb. in Wenlock-Ludlow boundary sediments are also presented. In the upper part of the section along the stream Bezymyanny a positive C-isotopic shift of the curve which possibly marks the late Wenlock global biotic event of Mulde was observed. Keywords: Ludlow, Wenlock, conodonts, brachiopods, Arctic region, Timan-Northern Ural region, isotope δ13Ccarb. [ABSTRACT FROM AUTHOR]

The paper presents the results of studying the geological structure of the Ludlowian boundary sediments and data on lithology, bio- and chemostratigraphy, and large-scale biotic reconstruction at the boundary Ludlow-Pridoli. The results obtained make it possible to draw a conclusion about the stratigraphic incompleteness of the Ludlow section in the Subpolar Urals and the interruption in sedimentation at the end of the Ludlow. [ABSTRACT FROM AUTHOR]

A study of patterns of episkeletobiont encrustation on the shells of two early Famennian brachiopods,CyrtospiriferzadonicusandRipidiorhynchus huotinusfrom Russia, revealed assemblages comprising seven skeletonised encruster taxa. The assemblages are dominated by spirorbiform microconchids, followed by cornulitids. Features such as shell malformations, frequent encruster growth towards the commissure of the shells, and encruster distribution in the areas adjacent to zones of possible water intake by the brachiopods indicate that these may have been colonisedsyn vivo. The lack of differences in encruster abundance between the two valves inC. zadonicusindicates that this species may have lived with both valves inclined at a high angle to the substrate. The significantly higher abundance of episkeletobionts on the brachial valves ofR.huotinusmay indicate that shells of this species were oriented with the brachial valve at a lower angle to the substrate, providing sheltered sites for coelobiotic larvae. Compared with pre-Famennian brachiopod-hosted encruster communities, this early Famennian community is impoverished in species richness and is dominated by microconchids. It is proposed that the epibionts witnessed a regression-related Frasnian–Famennian extinction event. During the recovery interval, opportunistic microconchids may have been among the first encrusters to colonise the pioneering brachiopods. [ABSTRACT FROM AUTHOR]

Abstract: A palaeontological record of the Northern Caucasus provides new data to evaluate the influence of the Permian/Triassic mass extinction on brachiopod communities. The study region is currently located in the southwest of Russia; it laid on the northern margin of the Palaeo-Tethys Ocean during the late Paleozoic-early Mesozoic. A total of 168 genera and 36 superfamilies are known from the Changhsingian-Bajocian deposits of this region. The total diversity of brachiopods was very high in the Changhsingian (57 genera and 19 superfamilies), but these organisms disappeared entirely at the Permian/Triassic boundary. Three genera and three superfamilies existed in the Induan, but brachiopods perished again in the Olenekian. A recovery began in the Anisian, but the Changhsingian diversity was never reached again. No genera crossed the Permian/Triassic boundary, whereas 4 superfamilies became able to do this. Ambocoelioidea was a “dead clade walking” and went extinct in the Induan, whereas three other superfamilies (Dialasmatoidea, Rhynchonelloidea, and Wellerelloidea) were more successful. Survivors included no less than 20% of genera during the entire Induan-Bajocian time interval. The Changhsingian-Anisian interval is dominated by just one type of facies in the studied region, which may explain differences in the post-extinction diversity patterns between the Northern Caucasus, South China, and other parts of the World. Use of the alternative Triassic time scale does not change the absolute duration of the post-extinction stress (5.1myr), whereas it highlights higher rates for the Anisian recovery (appearance of 0.9 superfamilies and 2.8 genera per myr). [Copyright &y& Elsevier]

A complete Hirnantian sequence comprising the Normalograptus extraordinarius and N. persculptus biozones is well developed at the Mirny Creek section in the Omulev Mountains. The underlying beds are assigned to the Appendispinograptus supernus Biozone, and in the overlying strata the lower boundary of the Silurian is precisely defined at the base of the Akidograptus ascensus Biozone. Due to the completeness of the sedimentary and palaeontological record, the Mirny Creek section can be considered as a reference section for the Hirnantian Stage. The succession, about 100 m thick, is composed of calcareous siltstones and marls with pebble-shaped limestones, deposited at a high sedimentation rate in shallow shelf settings. The regional stratotype section and point (RSSP) for the lower boundary of the Hirnantian is established at the base of member 68, where Normalograptus extraordinarius first appears. This level can be precisely correlated with that at the GSSP section in Yichang and with the sections in Kazakhstan and North America. The position of the Ordovician.Silurian boundary is redefined and placed at the FAD of A. ascensus at the base of member 74. [ABSTRACT FROM AUTHOR]

Athyrisinine brachiopods from the Upper Silurian of Russia and the Lower–Middle Devonian of China and north Vietnam include over 70 species belonging to Athyrisina and Parathyrisina; generic and subfamilial diagnoses are emended. Five genera are considered synonyms of Athyrisina and three of Parathyrisina. A neotype is selected and illustrated for Athyrisina squamosa, the type species of Athyrisina. Four nomina nova, Athyrisina xui, Parathyrisina wani, P. minima, and P. cheni, are suggested as new substitute names for Athyrisina tumida Wang, in Xu et al. 1978 (primary homonymy), Athyrisinoides ganxiensis Wan, in Xu et al. 1978, Parathyrisina minor Zhang, in Zhang and Fu 1983, and Athyrisinoides tudilingensis Chen, 1979 (secondary homonyms) respectively. A new genus, Bruntosina, is described from the Emsian to Eifelian of the Qinling region. A new subfamily, Homeathyridinae, is erected within the Athyrididae with Homeathyris, Pseudohomeospira, and Squamathyris included, revised and their diagnoses emended. Homeathyris incisus sp. nov. is described from the Ludfordian of Novaya Zemlya. Ikella is revised and excluded from the athyrisinins. The origin and dispersal of the homeathyridins and the athyrisinins are discussed. [ABSTRACT FROM AUTHOR]