Results 1 to 10 of about 3,600 (212)

Acritarchs of the Mesozoic of Ukraine

open access: yesВісник Харківського національного університету імені В.Н. Каразіна. Серія Геологія. Географія. Екологія, 2021
Introduction. Acritarchs are one of the orthostratigraphic groups of microfossils that are widely used in Proterozoic and Paleozoic biostratigraphy.
Olena Shevchuk, Kateryna Ivanchenko
doaj   +2 more sources

Global palaeogeographical implication of acritarchs in the Upper Ordovician [PDF]

open access: yesEstonian Journal of Earth Sciences, 2023
The Early–Middle Ordovician peri-Gondwana and Baltica acritarch provinces are easily recognizable, illustrating a clear provincialism of global phytoplankton.
Yan Kui   +4 more
doaj   +1 more source

Paleontological Evidence for Dinoflagellates and Ciliates as Early Eukaryotes

open access: yesJournal of Marine Science and Engineering, 2023
Molecular trees and geochemical markers suggest the divergence of dinoflagellates as early eukaryotes (~650 million years ago), but the traditional fossil record of cysts (dinocysts) starts during the Triassic (~230 million years ago). A re-evaluation of
Barrie Dale
doaj   +1 more source

Doushantuo-Pertatataka—Like Acritarchs From the Late Ediacaran Bocaina Formation (Corumbá Group, Brazil)

open access: yesFrontiers in Earth Science, 2021
Acritarchs, a polyphyletic group of acid-resistant organic-walled microfossils, dominate the eukaryotic microfossil record in the Proterozoic (2500–541 Ma) yet exhibit significant reduction in diversity and size at the transition to the Phanerozoic (541 ...
L. Morais   +10 more
doaj   +1 more source

New data on acritarchs from the Upper Ordovician of the Tungus basin, Siberian Platform [PDF]

open access: yesEstonian Journal of Earth Sciences, 2014
Distinctive late Ordovician acritarch assemblages have been discovered for the first time from about a 100 m sedimentary succession exposed along the Bol¢shaya Nirunda River in Siberia.
Elena Raevskaya, Andrei Dronov
doaj   +1 more source

Hiddenocysta matsuokae gen. nov. et sp. nov. from the Holocene of Vancouver Island, British Columbia, Canada [PDF]

open access: yes, 2021
A new dinoflagellate cyst genus and species are described here as Hiddenocysta gen. nov. and Hiddenocysta matsuokae sp. nov. from Holocene sediments in a core from the west coast of Vancouver Island (British Columbia, Canada).
Bogus, Kara   +5 more
core   +2 more sources

Iso-Naakkima, a circular structure filled with Neoproterozoic sediments, Pieksämäki, southeastern Finland [PDF]

open access: yesBulletin of the Geological Society of Finland, 1993
A circular Bouguer gravity anomaly with a minimum of -4.0 mGal and half amplitude width of 2 km was recognized at Lake Iso-Naakkima (62°11'N, 27°09'E), southeastern Finland.
S. Elo   +4 more
doaj   +1 more source

Chronostratigrahy of Acritarchs and Chitinozoans from upper Ordovician Strata from the Robat-e Gharabil Area, NE Alborz Mountains, Northern Khorassan Province: Stratigraphic and Paleogeographic Implications [PDF]

open access: yesJournal of Sciences, Islamic Republic of Iran, 2018
The Palaeozoic rock units mainly, Ghelli, Niur, Padeha, Khoshyeilagh and Mobark formations are well-exposed in the north of Robat-e Gharabil village. 116 out of 157 surface samples were analyzed to determine aged relationships of Ghelli Formation.
M. Ghavidel-Syooki, S. Borji
doaj   +1 more source

Discovery of the messaoudensis–trifidum acritarch assemblage (upper Tremadocian–lower Floian, Lower Ordovician) in the subsurface of Morocco [PDF]

open access: yesEstonian Journal of Earth Sciences, 2015
The upper Tremadocian to lower Floian messaoudensis–trifidum acritarch assemblage was first described from the Skiddaw Group of England and subsequently from several localities on the Gondwanan margin that were positioned in high southern latitudes ...
Hendrik Nowak   +3 more
doaj   +1 more source

Biostratigraphy and palaeoecology of marine microphytoplankton cysts from Member 4 of the Mila Formation, Mila Kuh, eastern Alborz [PDF]

open access: yesJournal of Stratigraphy and Sedimentology Researches, 2019
Well preserved and diverse organic-walled marine microphytoplankton cysts (acritarchs sensu lato) occur in Member 4 (comprising mostly of fine-grained clastics with thin carbonate intercalations) of the Mila Formation at the type section, southwestern ...
Navid Navidi-Izad, Hossein Hashemi
doaj   +1 more source

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