Results 101 to 110 of about 169 (141)

Ordovician chitinozoan zones from Baltoscandia

Review of Palaeobotany and Palynology, 1993
On the basis of reports published over the last 60 years, and unpublished data, a chitinozoan zonation is proposed for the Ordovician sequence of Scandinavia, the East Baltic, northeast Poland and Podolia—commonly referred to a Baltoscandia. From the first chitinozoans in the latest Tremadoc to the latest Ashgill (a period comprising ca.
Jaak Nõlvak, Yngve Grahn
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Ordovician chitinozoan biozonation of the Brabant Massif, Belgium

Review of Palaeobotany and Palynology, 2000
Chitinozoans from seven Ordovician units (Abbaye de Villers, Tribotte, Rigenée, Ittre, Bornival, and Brutia formations and a new unnamed unit, here provisionally called the Asquempont unit) belonging to the mainly concealed Brabant Massif, Belgium are described herein. Fifty-six samples were taken from rocks cropping out at the south-eastern rim of the
J, Samuelsson, J, Verniers
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Ordovician chitinozoan diversification events in China

Science in China Series D: Earth Sciences, 2004
Correlative study of the Ordovician chitinozoan biostratigraphy in China with graptolite and conodont biozones, and comprehensive analysis of the sequence- and event-strati-graphic indicated that 17 chitinozoan zones and 5 main chitinozoan diversification events subsequently occurring could be recognized in the Ordovician System of China.
Xiaofeng Wang, Xiaohong Chen
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Emergence, biodiversification and extinction of the chitinozoan group

Geological Magazine, 2010
AbstractChitinozoans are considered as reproductive bodies of marine invertebrates, called chitinozoophorans. These chitinozoophorans were most likely to have been small, pelagic or necto-pelagic, soft-bodied, probably wormlike animals, and judging from the size of chitinozoans, they probably measured from a few millimetres to a few centimetres in ...
YNGVE GRAHN, FLORENTIN PARIS
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Ultrastructural studies of some chitinozoan vesicles

Lethaia, 1980
Four species of Ordovician Chitinozoa from Oland, Sweden, Cyathochitina stentor, Desmochitina minor, Lagenochitina esthonica, and Lagenochitina tumida, have been investigated by transmission electron microscopy. There is very great variation in the vesicle wall ultrastructure of the specimens studied.
Yngve Grahn, Björn A. Afzelius
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Reflected light microscopy of chitinozoan fragments

Marine and Petroleum Geology, 1985
Abstract Certain optical properties of some Silurian-Ordovician chitinozoans have been measured and their morphology described, using polished, block-mounted samples and polished thin sections. The chitinozoans were found to be optically isotropic and many fine details of their morphology were observed using reflected light microscopy.
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Arenigian chitinozoans from the Klabava formation, Bohemia

Review of Palaeobotany and Palynology, 1984
Abstract The lower Paleozoic succession in Bohemia progressively emerges as a first-order reference in the international stratigraphical scale. This is the reason why investigations have been carried out on chitinozoans from the Klabava Formation which represents the Arenig Series in the Prague Basin.
Florentin Paris, Michal Mergl
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Chitinozoan implications in the palaeogeography of the East Moesia, Romania

Palaeogeography, Palaeoclimatology, Palaeoecology, 2006
Abstract Palaeomagnetic data from Moesia are absent and previous palynological and macrofaunal studies could not show clearly the palaeogeographical position of Moesia between the larger palaeocontinents Gondwana, Baltica, or Avalonia. Cutting samples from three boreholes on East Moesia (SE Romania) have been investigated in this study using S.E.M ...
Marioara Vaida, Jacques Verniers
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The Ordovician chitinozoan biodiversification and its leading factors

Palaeogeography, Palaeoclimatology, Palaeoecology, 2007
Abstract Regional and global dataset now available for almost all of the Ordovician fossil groups have led to a search for the causes controlling the major biodiversification events that occurred during the Ordovician period. A review of the physico-chemical state of the Ordovician world is presented, with an emphasis on the regional or global ...
Achab, Aïcha, Paris, Florentin
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Earliest chitinozoans discovered in the Cambrian Duyun fauna of China

Geology, 2012
Chitinozoans are an enigmatic group of organic-walled marine microfossils with an abundant Lower Ordovician to Upper Devonian fossil record. They achieved maximum species diversity during the Middle Ordovician-Silurian, and their history during the group's acme is well documented.
C. Shen, R. J. Aldridge, M. Williams, T. R. A. Vandenbroucke, X.-g. Zhang   +4 more
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