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Wyświetlanie 1-2 z 2
Tytuł:
The Frasnian-Famennian brachiopod extinction events: A preliminary review
Autorzy:
Racki, G
Powiązania:
https://bibliotekanauki.pl/articles/20065.pdf
Data publikacji:
1998
Wydawca:
Polska Akademia Nauk. Instytut Paleobiologii PAN
Tematy:
Pentamerida
fauna
China
America
Palmatolepis rhenana
Atrypida
morphology
mass extinction
Ural Mountains
taxonomy
Brachiopoda
Famennian
Frasnian
brachiopod
Devonian
Kellwasser Crisis
biogeography
biostratigraphy
distribution
paleontology
Opis:
Preliminary review of taxonomy of the brachiopod order Atrypida and its stratigraphic distribution in the late Frasnian Kellwasser Crisis of several regions of Laurussia, western Siberia and South China point to their moderate diversity and stepdown but irregular extinction pattern. The distinctive character of the late Frasnian atrypid fauna is emphasised by several relict genera, marked by recurrent and possibly aberrant characters (mainly in ornamentation types), tendency to size reduction and homeomorphy in some taxa. The transgressive/hypoxic Lower Kellwasser Event and preceding eustatic changes during the Palmatolepis rhenana Zone had only a regional destructive effect, and were linked rather to an enhanced dispersal of the last generic set of atrypids. The Variatrypinae, Spinatrypinae and Iowatrypa-group seem to belong to the latest surviving atrypids. The final demise of the remaining atrypids (and some other articulate brachiopods, e.g., gypidulids) coincided with the transgressive/hypoxic Upper Kellwasser Event, followed by catastrophic eustatic fall during the late Palmatolepis linguiformis Zone (F-F Event). This was probably exacerbated by accelerated submarine volcano-hydrothermal activity, and consequent progressive regional eutrophication, and climatic destabilization. The level-bottom rhynchonellid-inarticulate biofacies crosses the fatal F-F boundary horizon without major changes. No reliable data exist for the presence of atrypids in the Famennian survival and recovery biota, even for the smooth lissatrypid Peratos. Sustained competition from radiating and diversifying productid-cyrtospirifrid-athyrid faunas may have provide an additional biotic factor in the collapse of the Frasnian shelly benthos at the time of sfress, as well as in a post-extinction offshore repopulation from inner shelf habitats.
Źródło:
Acta Palaeontologica Polonica; 1998, 43, 2
0567-7920
Pojawia się w:
Acta Palaeontologica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Siliceous biota [radiolarians and sponges] and the Late Devonian biotic crisis: The Polish reference
Autorzy:
Vishnevskaya, V
Pisera, A.
Racki, G.
Powiązania:
https://bibliotekanauki.pl/articles/22703.pdf
Data publikacji:
2002
Wydawca:
Polska Akademia Nauk. Instytut Paleobiologii PAN
Tematy:
Astroentactinia stellata
Trilonche nigra
Polska
biotic crisis
Astroentactinia paronae
Trilonche echinata
mass extinction
taxonomy
Famennian
Frasnian
siliceous fauna
Late Devonian
Devonian
Radiolaria
carbonate shelf
Holy Cross Mountains
Trilonche grandis
paleoecology
distribution
paleontology
Opis:
The radiolarian species Astroentactinia paronae, A. stellata, Trilonche echinata, T. grandis, T. nigra, Haplentactinia inaudita, and H. rhinophyuosa are common in late Frasnian to early Famennian rhythmic, calcareous−marly sequence of the southern Holy Cross Mts., Poland. They are known also from coeval abundant siliceous biota assemblages from the carbonate shelf of East European Platform including more than 150 taxa of radiolarians. However, in ecological terms, the moderately diverse Polish microfaunas (34 species of 12 genera) are more similar to these from Kolyma and Alaska, also marked by abundance of sphaerical entactiniids and near−absence of bilateral−symmetric Ceratoikiscidae and Palaeoscenididae. A succession of two distinctive siliceous sponges associations is established in the incipiently submerged Holy Cross carbonate platform: from an ephemeral, diverse, mostly rigid−skeletal lithistid−hexactinosan foreslope assemblage (initial phase of the late Frasnian Kellwasser Crisis), to long−lasting, basinal loose−skeletal hexactinellid−demosponge faunas (appearing abundantly just prior the Frasnian–Famennian boundary in the late Palmatolepis linguiformis Zone). Such regional blooms of marine siliceous biotas, parallel to temporary retreat of calcareous biota, are demonstrated worldwide for the Kellwasser Crisis. These suggest probable causal links with cooling pulses and at least regional, volcanically induced eutrophication.
Źródło:
Acta Palaeontologica Polonica; 2002, 47, 2
0567-7920
Pojawia się w:
Acta Palaeontologica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
    Wyświetlanie 1-2 z 2

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