Results 131 to 140 of about 455 (173)

Frasnian conodonts from the eastern Russian Platform

Paleontological Journal, 2008
The Frasnian conodonts of the eastern Russian Platform from the Timan in the north to the Orenburg Region in the south are characterized in detail both paleontologically and stratigraphically. This paper is a continuation of a previously published monograph (Ovnatanova and Kononova, 2001) on the Frasnian conodonts of the shallow-water strata of the ...
N. S. Ovnatanova, L. I. Kononova
exaly   +2 more sources

The global Frasnian-Famennian »Kellwasser Event«

Geologische Rundschau, 1991
During the UppermostP. gigas conodont zone (P. linguiformis zone) the stepwise Frasnian extinction culminates in the global transgressive-regressive Frasnian-Famennian »Kellwasser event«. Most pelagic organisms of the tropical marine environment are more or less affected by this mass extinction.
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Influence of the Frasnian-Famennian event on radiolarian faunas

Eclogae Geologicae Helvetiae, 2006
The impact of the Frasnian-Famennian biotic mass extinction event (F-F event) on radiolarian faunas is examined in 13 sections, which belong to two types of cherty basin in South China. No appreciable decrease in radiolarian biodiversity is observed across the F-F boundary. Indeed, radiolarian faunas flourished during the Famennian.
Wang, Yu-Jing, Luo, Hui, Aitchison, Jonathan C.   +2 more
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Carbon isotope geochemistry of the Frasnian–Famennian transition

Palaeogeography, Palaeoclimatology, Palaeoecology, 2002
Abstract Carbon isotope records for inorganic and total organic carbon (TOC) as well as for individual organic biomarkers show two positive excursions in the Late Frasnian with comparable shape and amplitude in δ13C. The positive shifts in δ13C can be correlated with the deposition of the Kellwasser horizons.
Joachimski, MM, Pancost, RD, Freeman, KH, Ostertag-Henning, C, Buggisch, W   +4 more
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Atrypid Brachiopods from the Upper Devonian Wangchengpo Formation (Frasnian) of Southern Guizhou, China-Extinction Patterns in the Frasnian of South China

Acta Geologica Sinica - English Edition, 2005
The Wangchengpo Frasnian section of Dushan County contains two atrypid brachiopod assemblages. The lower is characterized by the Atryparia (Costatrypa) dushanensis fauna that appears at the base of the Hejiazhai Member approximately in the falsiovalis to transitans conodont zones; the upper is characterized by the Radiatrypa yangi fauna, which appears ...
MA Xueping, Paul COPPER, SUN Yuanlin, LIAO Weihua   +3 more
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Biostratigraphy of the Frasnian stage by radiolarian evidence

2001
Revising Frasnian radiolarians, we established three new radiolarian zones within this stage. These are the Helenifore gogoense-Retisphaera concinna Zone of the lower Frasnian, Moskovistella allbororum-Ceratoikiscum ukhtensis Zone of the middle Frasnian, and Bientactinosphaera egindyensis - Polyentactinia circumretia Zone of the upper Frasnian.
Afanas'eva, MS, Aitchison, JC
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Effect of the Frasnian-Famennian extinction event on the stromatoporoids

Geology, 1987
Although Paleozoic stromatoporoids were drastically reduced in abundance and diversity by the Frasnian-Famennian (F/F) mass extinction event, at least 20 genera (mostly labechiids and clathrodictyids) are known from latest Devonian rocks. Some typical Frasnian genera survived the F/F crisis to die out in early Famennian time, and others took part in ...
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Evolution of the last Tropidocoryphinae (Trilobita) during the Frasnian

2005
Early Upper Devonian Tropidocoryphinae (Proetida, Trilobita) show unequivocal evidence of eye-reduction leading to blindness and extinction slightly before or during the Kellwasser Event. The obviously gradualistic evolution can be related to environmental change.
Raimund Feist, Euan N. K. Clarkson
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Quantification of outlines in Frasnian (Upper Devonian) platform conodonts

Canadian Journal of Earth Sciences, 1986
The outline of the platform in Pa elements of conodont genera such as Palmatolepis is commonly one of the most heavily weighted taxonomic characters. But a taxonomy based only on visual discrimination of Pa elements of Frasnian species of Palmatolepis has resulted in widespread misidentification.
Gilbert Klapper, C. T. Foster Jr.
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The semichatovae Transgression (basal upper Frasnian) in Morocco

The semichatovae Transgression marks an episode of major eustatic sea level rise in the Upper Devonian. It is commonly described by the wide spread of the index conodont Palmatolepis semichatovae and has been proposed to define the boundary between the middle and upper Frasnian substages within Frasnian conodont zone 11. The index species is known from
Großklaus, Maximilian*, Becker, Ralph Thomas   +1 more
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