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1
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Early-Middle Frasnian cyrtospiriferid brachiopods from the East European Platform

100%
Sokiran E. V.
Acta Palaeontologica Polonica
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2006
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tom 51
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nr 4
759-772
The cyrtospiriferids are among the most important fossils in the Frasnian strata of the East European Platform (EEP). During the Early Frasnian (Palmatolepis falsiovalis Zone) the numerous and morphologically distinct Uchtospiriferinae, accompanied by very scarce Cyrtospiriferinae, are known from South Timan. The mass appearance of cyrtospiriferins on the platform at the beginning of the Middle Frasnian is linked with significant sea−level rise of Devonian Transgression−Regression (T−R) cycle IIc. At that interval these brachiopods attain their highest diversity of the entire Frasnian. The Early Frasnian type species of the genus Uchtospirifer is here revised, and subfamily Uchtospiriferinae re−established. Cyrtospirifer schelonicus, C. rudkinensis, C. mylaensis sp. nov., and C. tenticulum are described from the Middle Frasnian of NW and central regions of EEP and Middle Timan.
2
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Faunal and facies changes at the Early-Middle Frasnian boundary in the north-western East European platform

100%
Zhuravlev A. V., Sokiran E. V., Evdokimova I. O., Dorofeeva L. A., Rusetskaya G. A., Malkowski K.
Acta Palaeontologica Polonica
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2006
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tom 51
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nr 4
747-758
Multidisciplinary study of the Early–Middle Frasnian boundary in the north−western East European Platform (Main Devonian Field) allows evaluation of changes in facies, brachiopod, ostracod, and conodont associations, as well as carbon isotope composition. Brachiopod and ostracod faunas, characterized by predominance of rhynchonellids, spiriferids, podocopids, and platycopids in the Early Frasnian, and by predominance of spiriferids, palaeocopids, and kloedenellocopids in the Middle Frasinan, demonstrate significant changes in dominance and diversity likely caused by regressiontransgression couplets in the extremely shallow−water environment. Changes in diversity of the conodont associations, represented mainly by shallow−water polygnathids and spathognathids, are controlled by sea−level fluctuations as well; however significant evolutionary turnover is absent. Deepening pulses lead to an increasing in diversity of both the benthic and nectic groups, whilst regressions cause diversity fall due to progressive habitat reduction. Most prominent decreasing in the fauna diversity is observed in the late Early Frasnian (Dubnik time) coinciding with the regressive phase of the Late Givetian to Early Frasnian eustatic cycle. Positive−negative δ¹³C excursion, detected in brachiopod calcite from the early interval of the Middle Frasnian, can be correlated with global isotopic perturbations near the Frasnian substage boundary: the positive 2.6‰ δ¹³C excursion is probably linked with enhanced primary production in high−nutrient regimes in the epeiric sea.
3
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Benthic ostracods from the Early-Middle Frasnian transition in the north-western East European Platform, Russia

100%
Evdokimova I. O.
Acta Palaeontologica Polonica
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2006
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tom 51
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nr 4
773-778
Pronounced changes in benthic ostracod associations in the north−west part of the East European Platform, across the Early–Middle Frasnian (Devonian) transition, track a marine transgression event. More than 80 ostracod species belonging to the Eifelian Mega−Assemblage were recorded. Cavellinidae and Acratiidae generally dominate the Early Frasnian Sargaevo Horizon. Middle Frasnian ostracod associations of the Semiluki Horizon are more diverse and are characterised by different dominant both geographically and stratigraphically, resulting from significant palaeo−basin bottom relief and benthic biotope differentiation. The ostracod associations are indicative of very shallow, well oxygenated semi−restricted epeiric environment, with occasional marine influence, alternating with short periods of open shelf conditions. The relative abundance of ostracod species in the different associations, and faunal diversity indices, show considerable variations throughout the Early–Middle Frasnian, and suggest a less restricted position within an intra−platform setting in the Middle Frasnian, relative to a more restricted ostracod habitat in the Early Frasnian. The succession of Early–Middle Frasnian micro−benthic associations within the Main Devonian Field seems to be of a regional scale, and resulted from a marine regression−transgression couplet, corresponding to eustatic cycles IIb–IIc. This was paired with synsedimentary tectonic subsidence in adjacent areas of the north−east East European Platform, progressively improving marine water circulation in the extremely shallow−water shelf seas.
4
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Heckerella, a new genus of the Early Frasnian [Late Devonian] atrypid brachiopod

100%
Rzonsnitskaya M. A., Sokiran E. V.
Acta Palaeontologica Polonica
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2000
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tom 45
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nr 4
A new atrypid genus Heckerella from early Frasnian (Palmatolepis transitans Zone) of northwestern East European Platform is proposed. It includes only Heckerella heckeri, originally referred to Anatrypa. The new genus is characterised by weakly paraplicate anterior commissure, well-developed carina on the ventral valve, sulcus on the dorsal valve and coarser radial ornament. Heckerella has restricted geographic distribution in northwestern Russia, Latvia, northeastern Lithuania where it forms high-density associations with Pseudoatrypa velikaya.
5
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Kirkigraptus, a new retiolitid graptolite from Poland

80%
Kozlowska A., Bates D. E. B.
Acta Palaeontologica Polonica
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2008
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tom 53
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nr 1
The new retiolitid graptolite Kirkigraptus inexpectans gen. et sp. nov., from the Neodiversograptus nilssoni Biozone of the Bartoszyce borehole, Poland is described. It is unique among the retiolitids not having a preserved virgella or ancora. Instead the most proximal structures are two round proxi−lateral lists, joining the two genicular lists of the first thecae, connecting the two sides of the rhabdosome. The lists are interpreted as a possible homologue of the distal edge of the ancora umbrella in typical retiolitids. The size of rhabdosome with large proximal lateral orifices, and the ventral panels of thecae with mid−ventral lists, are similar to those of Plectograptus, whereas the two ancora sleeve panels consisting of spaced horizontal lists only, resemble those of Valentinagraptus. It is possible that the new retiolitid may represent a new pattern of development of the proximal end of the rhabdosome, different from that in all other retiolitids.
6
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Frasnian-Famennian extinction and recovery of rhynchonellid brachiopods from the East European Platform

80%
Sokiran E. V.
Acta Palaeontologica Polonica
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2002
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tom 47
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nr 2
In contrast to dramatic losses of the Atrypida and Pentamerida at the Frasnian–Famennian boundary, the Rhynchonellida demonstrated relatively high rate of survival, and recolonized vacated benthic ecospace after the F–F extinction events. The Late Devonian evolution of rhynchonellid faunas from the East European Platform shows three distinctive periods of their mass appearance. High abundance of rhynchonellids is characteristic for early–middle Frasnian (Palmatolepis transitans–Pa. punctata zones) and early Famennian (Pa. crepida Zone). Invasion of taxonomically diverse and rich rhynchonellid faunas usually corresponds to the major transgressive episodes, whereas decline coincides with regressive conditions of the basin. Rhynchonellid assemblages were replaced in the late Frasnian (Late Pa. hassi–Pa. linguiformis zones) by theodossiid− and cyrtospiriferid−dominated assemblages, which occupied habitats in newly expanding marine environments. The extinction of theodossiids at the end of the Frasnian and the next transgressive episode possibly stimulated an expansion of rhynchonellids. The early Frasnian species Ripidiorhynchus livonicus (Buch, 1834), and the early Famennian R. huotinus (Verneuil, 1845) and R. griasicus (Nalivkin, 1934) are revised. Early Famennian species Paromoeopygma koscharica (Nalivkin, 1934) from the central region is redescribed. Ripidiorhynchus chencinensis sp. nov. from the latest Givetian of Poland, as well as Globulirhynchia minima sp. nov. from the late Frasnian of the central region of the Russia, are described.
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Phyletic evolution and iterative speciation in the persistent Pristiograptus dubius lineage

71%
Urbanek A., Radzevicius S., Kozlowska A., Teller L.
Acta Palaeontologica Polonica
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2012
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tom 57
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nr 3
The paper focuses on patterns of the evolution of the simplest and longest−ranging (approximately 18 Ma) Silurian graptolite Pristiograptus dubius. The Pristiograptus dubius species group consists of the P. dubius stem lineage represented by a sequence of a number of subspecies displaying only small morphological changes as well as derivative species produced from the stem lineage by means of iterative speciation. This long raging graptolite lineage is the only one, apart of one retiolitid, which survived the most severe environmental event for graptolites, the Cyrtograptus lundgreni Event. Based on three−dimensional, isolated material two P. dubius groups taxa are distinguished. One group has an obtuse angle between the thecal lip and the succeeding thecal wall, the second group has a right or acute angle. Other characters differentiating P. dubius forms are: the shape of the apertural lips, differences in rhabdosome shape and size, and a different number of sicular rings. Sixteen species and subspecies of Pristiograptus from the East European Platform, Poland and Lithuania are discussed. Five new subspecies P. dubius magnus, P. dubius paezerensis, P. dubius praelodenicensis, P. dubius postfrequens, and P. dubius postmagnus are proposed.
8
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Geologiczno-geomorfologiczna ewolucja polnocno-zachodniej czesci Polesia Wolynskiego

71%
Bogucki A., Zaleski I., Karpenko N., Kowalczuk I., Krawczuk J.
Acta Agrophysica
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2003
|
tom 01
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nr 2[87]
217-232
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