Results 171 to 180 of about 1,517 (200)

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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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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Raman spectroscopy of chitinozoans as a maturation indicator

Organic Geochemistry, 1995
Abstract Micro-Raman spectra were acquired from a series of individual chitinozoans of low ( R ch 0.6%) to high thermal maturity ( R ch 5.1%). This provides information on their molecular and structural characteristics. All spectra show two broad bands on a fluorescent background at ∼ 1600 and 1355 cm −1 .
S. Roberts, P.M. Tricker, J.E.A. Marshall   +2 more
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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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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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Chitinozoan reflectance: a Lower Palaeozoic thermal maturity indicator

Marine and Petroleum Geology, 1992
Abstract Chitinozoan reflectance ( R ch ) is an innovative technique of thermal maturation determination suitable for Lower Palaeozoic sediments where the established reflectance scale, vitrinite reflectance ( R v ), is not applicable due to the lack of vitrinite.
Paul M. Tricker, John E.A. Marshall, Tim D. Badman   +2 more
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Ordovician Chitinozoans from Florida Well Samples: ABSTRACT

AAPG Bulletin, 1969
Ordovician chitinozoans recovered from a grayish-black shale are described for the first time for subsurface north-central Florida. The lowest sample of the Sun Oil Company, Earl Odom No. 1 well, Suwannee County, Florida, is dated between late Arenigian and early Caradocian. The Ordovician is overlain directly by Silurian rocks.
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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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Silurian Chitinozoans from Florida Well Samples: ABSTRACT

AAPG Bulletin, 1969
End_Page 2036------------------------------Chitinozoans of Silurian age were recovered from four wells in Florida: Cone No. 1, Tillis No. 1, Hilliard No. 1, and Kie Vining No. 1. An attempt was made to establish a correlation between the four wells using the chitinozoan evidence, and the results are presented.
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Early Ordovician scolecodonts and chitinozoans from Tallinn, North Estonia

Review of Palaeobotany and Palynology, 2006
Abstract In the Lower Ordovician siliciclastic succession of Kadriorg, Tallinn, North Estonia, scolecodonts were recorded at different stratigraphical levels starting from the lower Tremadocian, and a rich assemblage of chitinozoans was found from the Paroistodus proteus Conodont Zone.
Olle Hints, Jaak Nõlvak
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