Informacja

Drogi użytkowniku, aplikacja do prawidłowego działania wymaga obsługi JavaScript. Proszę włącz obsługę JavaScript w Twojej przeglądarce.

Wyszukujesz frazę "Maastrichtian" wg kryterium: Temat


Tytuł:
Magnetostratigraphy of the Campanian/Maastrichtian boundary succession from the Middle Vistula River section, Central Poland
Autorzy:
Plasota, T.
Nawrocki, J.
Walaszczyk, I.
Powiązania:
https://bibliotekanauki.pl/articles/2059995.pdf
Data publikacji:
2015
Wydawca:
Państwowy Instytut Geologiczny – Państwowy Instytut Badawczy
Tematy:
magnetostratigraphy
Campanian-Maastrichtian boundary
Polska
Opis:
The magnetic polarities of the upper Upper Campanian–Lower Maastrichtian interval of the Middle Vistula River composite section (central Poland), were studied. Sixty-six hand-oriented samples for palaeomagnetic studies were taken from the sections of Raj, Raj North, Podole, Kłudzie and Dziurków. The inter-correlation between them is based primarily on bio-events. The sampled rocks generally revealed a very weak magnetic signal, however quite reliable results were obtained. The whole interval studied, well constrained biostratigraphically, is referred to magnetostratigraphic chron C32n. The Campanian–Maastrichtian boundary, placed biostratigraphically in the upper part of the ‘Inoceramus’ redbirdensis inoceramid Zone, is located near the top of the C32n2n Subchron. Thin reversed polarity intervals in the rocks correlated with the C32n2n chron most probably result from their partial remagnetization (maghemitization).
Źródło:
Geological Quarterly; 2015, 59, 4; 831--842
1641-7291
Pojawia się w:
Geological Quarterly
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The Belemnitella stratigraphy of the Upper Campanian : basal Maastrichtian of the Middle Vistula section, central Poland
Autorzy:
Remin, Z.
Powiązania:
https://bibliotekanauki.pl/articles/2059997.pdf
Data publikacji:
2015
Wydawca:
Państwowy Instytut Geologiczny – Państwowy Instytut Badawczy
Tematy:
Campanian
Maastrichtian
Vistula section
belemnites
biostratigraphy
artificial Neural Networks
Campanian-Maastrichtian boundary
Opis:
This taxonomy and stratigraphy of the Upper Campanian and Lower Maastrichtian Belemnitella lineages, from the Middle Vistula sections, based on new collections, is presented. The correlation to the basal Maastrichtian standard GSSP at Tercis, France, is provided based on inoceramid bivalve stratigraphy. The Artificial Neural Networks (ANN), particularly the self-organizing Kohonen algorithm, was applied to taxonomic discrimination. Eight morphotypes within the genus Belemnitella, understood here as natural species populations, were recognised. Five of these are assigned to known taxa: Belemnitella mucronata, B. posterior, B. minor [= B. minor I and B. minor II], B. langei and B. najdini; and three, B. sp. a, B. sp. 1 and B. sp. 2, are left in open nomenclature. Four Belemnitella zones are proposed. Due to its palaeogeographic position, between Western and Eastern Europe, the Middle Vistula section is characterized by the co-occurrence of Belemnitella species from those two areas. Consequently, it enables better correlation of Belemnitella-based schemes; the East European B. najdini and B. posterior are placed next to West European B. minor chronospecies I and II. The Campanian/Maastrichtian boundary, as currently defined, is placed at the top of the najdini – posterior Zone, which is an equivalent of the Belemnella-based boundary, i.e. at the base of the Belemnella obtusa / Belemnella vistulensis zones. Within the top of the najdini – posterior Zone occurs a level (an interval of only a few metres), where nearly all of the Upper Campanian Belemnitella disappear. This level coincides with taxonomic changes observed within the co-occurring representatives of genus Belemnella.
Źródło:
Geological Quarterly; 2015, 59, 4; 783--813
1641-7291
Pojawia się w:
Geological Quarterly
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The Upper Cretaceous variegated shales in the Ropianka Formation of the Magura Nappe (Outer Carpathians) : age and lithostratigraphic position
Autorzy:
Waśkowska, Anna
Szczęch, Mateusz
Powiązania:
https://bibliotekanauki.pl/articles/31342966.pdf
Data publikacji:
2023
Wydawca:
Państwowy Instytut Geologiczny – Państwowy Instytut Badawczy
Tematy:
Campanian-Maastrichtian
red beds
lithostratigraphy
biostratigraphy
foraminifera
Opis:
The lithological characteristics and age analysis of the variegated Farony Shale are presented for the first time. The Farony Shale occurs in the Lubomierz and Rabka areas in the Bystrica Subunit. It is located within medium- and thin-bedded sandy dominated turbidites of the Campanian–Paleocene Ropianka Formation. It is comprised of red shales laminated or interlayered with strongly bioturbated green shales. Exposures of the Farony Shale are observed along a distance of ~25 km, in the form of a narrow belt. The age of the variegated deposits is estimated based on agglutinated foraminifera to late Campanian–earliest Maastrichtian. Their deposition was associated with low-energy conditions and a temporary limitation of the supply of sandy material to the inner part of the Magura Basin.
Źródło:
Geological Quarterly; 2023, 67, 2; art. no. 18
1641-7291
Pojawia się w:
Geological Quarterly
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Theropod teeth from the upper Maastrichtian Hell Creek Formation “Sue” Quarry: New morphotypes and faunal comparisons
Autorzy:
Gates, T.A.
Zanno, L.E.
Makovicky, P.J.
Powiązania:
https://bibliotekanauki.pl/articles/945614.pdf
Data publikacji:
2015
Wydawca:
Polska Akademia Nauk. Instytut Paleobiologii PAN
Tematy:
paleontology
theropod
tooth
Upper Maastrichtian
Maastrichtian
Hell Creek Formation
morphotype
Dinosauria
morphometry
paleoecology
Cretaceous
North America
Opis:
Isolated teeth from vertebrate microfossil localities often provide unique information on the biodiversity of ancient ecosystems that might otherwise remain unrecognized. Microfossil sampling is a particularly valuable tool for documenting taxa that are poorly represented in macrofossil surveys due to small body size, fragile skeletal structure, or relatively low ecosystem abundance. Because biodiversity patterns in the late Maastrichtian of North American are the primary data for a broad array of studies regarding non-avian dinosaur extinction in the terminal Cretaceous, intensive sampling on multiple scales is critical to understanding the nature of this event. We address theropod biodiversity in the Maastrichtian by examining teeth collected from the Hell Creek Formation locality that yielded FMNH PR 2081 (the Tyrannosaurus rex specimen “Sue”). Eight morphotypes (three previously undocumented) are identified in the sample, representing Tyrannosauridae, Dromaeosauridae, Troodontidae, and Avialae. Noticeably absent are teeth attributed to the morphotypes Richardoestesia and Paronychodon. Morphometric comparison to dromaeosaurid teeth from multiple Hell Creek and Lance formations microsites reveals two unique dromaeosaurid morphotypes bearing finer distal denticles than present on teeth of similar size, and also differences in crown shape in at least one of these. These findings suggest more dromaeosaurid taxa, and a higher Maastrichtian biodiversity, than previously appreciated.
Źródło:
Acta Palaeontologica Polonica; 2015, 60, 1; 131-139
0567-7920
Pojawia się w:
Acta Palaeontologica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Palynological Study of the Campano-Maastrichtian Nkporo Group of Anambra Basin, Southeastern, Nigeria
Autorzy:
Chiadikobi, K. C.
Chiaghanam, O. I.
Onyemesili, O. C.
Omoboriowo, A. O.
Powiązania:
https://bibliotekanauki.pl/articles/1109375.pdf
Data publikacji:
2018
Wydawca:
Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Tematy:
Campano-Maastrichtian
Nkporo Formation
Palynology
Palynomorphs and Anambra Basin
Opis:
Palynological assemblages were used in the determination of the age and paleoenvironment of the Nkporo and Enugu Formations of the Anambra Basin, Southeastern Nigeria. Palynological analysis carried out in over twenty-five samples (25) yielded spores, pollens and marine species. The main diagnostic species of spores and pollen recovered includes; Foveotriletes margaritae, Distaverrusporites simplex, Cingulatisporites ornatus, Echitriporites trianguliformis, Longapertites marginatus, Proteacidites segali, Monocolpites marginatus, Constructipollenites ineffectus, Buttinia andreevi, and Retidiporites which were dated to Late Campanian to Earliest Maastrichtian. Also, other sporomorphs includes; Longapertites marginatus (overwhelming abundance), Longapertites microfoveolatus, Longapertites vaneedenburgi, Spinizonocolpites baculatus, Foveotriletes margaritae, Distaverrusporites simplex, Cingulatisporites ornatus, Matonisporites equiexinus, Azolla marsulae, Mauritidiites crassibaculatus, Constructipollenites ineffectus, Echitriporites trianguliformis, Foveotriletes margaritae, and Leiotriletes minor were assigned to Early Maastrichtian. From the palynological analysis, the age-diagnostic index palynomorphs reveal that the Nkporo Group is within Late Campanian to Early Maastrichtian and the depositional environment is mostly marginal marine to marine.
Źródło:
World News of Natural Sciences; 2018, 20; 31-53
2543-5426
Pojawia się w:
World News of Natural Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Palaeoenvironmental interpretation of dinosaur- and mammal-bearing continental Maastrichtian deposits, Hateg basin, Romania
Autorzy:
Bojar, A. V.
Grigorescu, D.
Ottner, F.
Csiki, Z.
Powiązania:
https://bibliotekanauki.pl/articles/2058894.pdf
Data publikacji:
2005
Wydawca:
Państwowy Instytut Geologiczny – Państwowy Instytut Badawczy
Tematy:
Hateg Basin
Maastrichtian
dinosaurs
paleosols
stable isotopes
clay mineralogy
Opis:
The Hateg basin, South Carpathians, Romania, contains a thick sequence of Maastrichtian continental deposits from which a rich dinosaur and mammal fauna is known. Field data as well as mineralogical and stable isotope analyses from three representative profiles were integrated in order to reconstruct environmental conditions during Maastrichtian time. Tustea quarry is characterized by the presence of well drained calcisols, with smectite (montmorillonite) as the main clay component. Along the profile, the δ18 O and δ13 C isotopic compositions of calcretes show a small variation, of up to 0.9‰. The profile along the Barbat Valley shows preponderantly calcisols, the main clay mineral being smectite, with subordinate illite and chlorite. The oxygen isotopic compositions of calcretes are ~0.5‰ lighter than those from Tustea. The soils are interpreted as having formed under more humid conditions and they are similar to those situated at the bottom of the sequence developed along Sibisel Valley. The abundant smectite from the Tustea and Barbat Valley depos its, as well the presence of good developed soils, reflects palaeoenvironmental conditions predominantly controlled by climate. Preliminary magnetostratigraphic data along the Sibisel Valley section indicate that sedimentation started at the end of chron C32n. All other palaeomagnetic sites distributed up stream, as far as the upper limit of this formation, have only reversed polarity and the corresponding time interval is probably chron C31r. Along this valley, the sequence shows a general coarsening upward trend. The palaeosol type changes from calcisol- to vertisol-dominated sequences. The soils are moderate to weakly developed. The mineralogical composition of the clay fraction also changes, from smectite- to illite and chlorite-dominated. These features points to wards unstable tectonic conditions and higher uplift rates of the surrounding area within chron C31r. To wards the top of the sequence, the oxygen and carbon isotopic composition of calcretes be come 1 and ~2‰ lighter, respectively. These changes indicate a transition from generally semi-arid to wards more humid and possible cooler conditions and correlate with the world wide trend for chron 31r.
Źródło:
Geological Quarterly; 2005, 49, 2; 205--222
1641-7291
Pojawia się w:
Geological Quarterly
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Comment on “A new Arctic hadrosaurid from the Prince Creek Formation (lower Maastrichtian) of northern Alaska” by Hirotsugu Mori, Patrick S. Druckenmiller, and Gregory M. Erickson
Autorzy:
Fiorillo, A.R.
Powiązania:
https://bibliotekanauki.pl/articles/20315.pdf
Data publikacji:
2016
Wydawca:
Polska Akademia Nauk. Instytut Paleobiologii PAN
Tematy:
new taxon
Arctic
hadrosaurid
Prince Creek Formation
Maastrichtian
Alaska
Źródło:
Acta Palaeontologica Polonica; 2016, 61, 1
0567-7920
Pojawia się w:
Acta Palaeontologica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A unique dentary suggests a third genus of batrachosauroidid salamander existed during the latest Cretaceous in the western USA
Autorzy:
Gardner, James D.
Powiązania:
https://bibliotekanauki.pl/articles/2216212.pdf
Data publikacji:
2022
Wydawca:
Polska Akademia Nauk. Instytut Paleobiologii PAN
Tematy:
Lissamphibia
Caudata
Batrachosauroididae
Cretaceous
Maastrichtian
Lance Formation
North America
Opis:
An incomplete salamander dentary (AMNH FARB 22965) described herein from the upper Maastrichtian Lance Formation, Wyoming, USA, exhibits a puzzling suite of features. Four features—a prominent bony trough extending anteriorly and curving upwards along the lingual surface of the ramus, lack of an obvious Meckelian fossa or groove, an apparent gap in the tooth row, and a symphysial-like first tooth—are likely anomalies. However, the remaining features are interpreted as normal structures and suggest that AMNH FARB 22965 represents a new genus and species of batrachosauroidid, an extinct family of neotenic salamanders that were prominent components of Cretaceous to Neogene freshwater and floodplain paleocommunities in North America and Europe. The new taxon differs from other batrachosauroidids in a unique suite of dentary and dental features, most notably in having a lingual bony flange paralleling the posterior two-thirds of the dentary tooth row, a prominent and robust coronoid process bearing a grooved anterior face, and the anterior portion of the corpus dentalis behind the symphysis is broadly expanded ventrolingually. The presence of a third batrachosauroidid taxon in the Lance Formation was unexpected, considering that the formation has been well sampled and that its two previously recognized batrachosauroidids, namely Opisthotriton kayi and Prodesmodon copei, are known by abundant isolated bones, including dozens of dentaries, from numerous localities in the unit and elsewhere in the North American Western Interior. Known by a unique dentary from the Bushy Tailed Blowout locality, the taxon represented by AMNH FARB 22965 evidently was uncommon within the Lance Formation paleoenvironment.
Źródło:
Acta Palaeontologica Polonica; 2022, 67, 1; 35-50
0567-7920
Pojawia się w:
Acta Palaeontologica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The Late Cretaceous Fucoid Marl of the Ropianka Formation in the Kąkolówka Structure (Skole Nappe, Outer Carpathians, Poland) : lithology and foraminiferal biostratigraphy
Autorzy:
Waśkowska, Anna
Joniec, Andrzej
Kotlarczyk, Janusz
Siwek, Piotr
Powiązania:
https://bibliotekanauki.pl/articles/191304.pdf
Data publikacji:
2019
Wydawca:
Polskie Towarzystwo Geologiczne
Tematy:
Skole Basin
Kropivnik Fucoid Marl
Campanian-Maastrichtian
lithostratigraphy
biostratigraphy
foraminifera
Opis:
A 250-m-thick sedimentary succession dominated by siliciclastic deposits occurs in the Kąkolówka Structure of the Skole Nappe. The succession was deposited in the inner part of the Skole Basin during the Late Cretaceous. In position and age, it corresponds to the Kropivnik Fucoid Marl of the Wiar Member (a subdivision of the Ropianka Formation), which was comprehensively described in the external part of the Skole Nappe. In this study, the authors provide the first complete data set on the lithological development and biostratigraphy of the Kropivnik Fucoid Marl from the inner part of the Skole Nappe. The results are compared to previous data from the outer part of the Skole Nappe. In the Kropivnik Fucoid Marl of the Kąkolówka Structure, three main heterolithic facies associations are distinguished: shale-sandstone, marl-sandstone and sandstone-shale. The occurrences of hard, platy and soft marls within siliciclastic rocks are typical of the sections studied. The features observed indicate a turbiditic origin of the deposits studied, including the hard, platy marls. The allogenic material of the strata described includes the small, fragile tests of planktonic foraminifera, which were redeposited from the outer parts of the Skole Basin. Particularly large concentrations of planktonic foraminifera were observed in the hard, platy marls. They are less common in the soft marls and shales. In the Zimny Dział section, a diverse assemblage of benthic and planktonic foraminifera was found. The Kropivnik Fucoid Marl was dated as uppermost Campanian to lowermost Maastrichtian on the basis of planktonic foraminifera, which represent the Gansserina gansseri Zone. The agglutinated foraminiferal assemblages are representative for the lower part of the Rzehakina inclusa Zone and the co-occurrence of the Caudammina gigantea (Geroch) acme with Rzehakina inclusa (Grzybowski) was observed.
Źródło:
Annales Societatis Geologorum Poloniae; 2019, 89, 3; 259-284
0208-9068
Pojawia się w:
Annales Societatis Geologorum Poloniae
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The Upper Campanian - lower Maastrichtian cephalopod fauna of Botellos, Nuevo León: a key to understand faunal turnover across the Campanian-Maastrichtian boundary in NE Mexico
Autorzy:
Ifrim, C.
Lara de la Cerda, J. E.
Peña Ponce, V. H.
Stinnesbeck, W.
Powiązania:
https://bibliotekanauki.pl/articles/139296.pdf
Data publikacji:
2017
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
ammonoids
Campanian
Maastrichtian
Mexico
faunal turnover
amonity
kampan
mastrycht
Meksyk
Opis:
A new cephalopod collection from the Campanian-Maastrichtian boundary interval of NE Mexico, consisting of 1076 individuals assigned to 29 species and 22 genera is presented. This collection is a mix of ammonoids, one coleoid and one nautilid, which originate from at least three ammonoid biozones: The upper Campanian Exiteloceras jenneyi and Nostoceras (Nostoceras) hyatti zones, and the lower Maastrichtian Pachydiscus (Pachydiscus) neubergicus Zone. The age of the collection is thus middle late Campanian to late early Maastrichtian, and it closes a stratigraphic gap between faunas described formerly from this region. The specimens are nuclei collected from the desert pavement. The abundance of specimens allows for a comparison to other Campanian-Maastrichtian ammonoid records from Mexico, North America and Europe.
Źródło:
Acta Geologica Polonica; 2017, 67, 1; 145-162
0001-5709
Pojawia się w:
Acta Geologica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The Belemnella stratigraphy of the Campanian-Maastrichtian boundary; a new methodological and taxonomic approach
Autorzy:
Remin, Z.
Powiązania:
https://bibliotekanauki.pl/articles/138983.pdf
Data publikacji:
2012
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
belemnity
biostratygrafia
kampan
Kronsmoor
mastrycht
sztuczne sieci neuronowe
Wisła
Artificial Neural Networks
belemnites
biostratigraphy
Campanian
Campanian-Maastrichtian boundary
Kronsmoor section
Maastrichtian
Vistula section
Opis:
The taxonomy and stratigraphy of the Upper Campanian and Lower Maastrichtian belemnites from the Vistula (central Poland) and Kronsmoor (northern Germany) sections are revised on the basis of new collections from the Vistula section as well as a reinvestigation of the classic collection of Schulz from the Kronsmoor section. For the taxonomic description a new biometric procedure is proposed, which can be applied to both the genera Belemnella and Belemnitella. For the species-level taxa recognition the Artificial Neural Networks method, the self-organizing Kohonen algorithm, was implemented. This new taxonomic and methodological approach enabled the recognition of nine species of the genus Belemnella. Five of them can be assigned to the existing species B. lanceolata, B. longissima, B. inflata, B. obtusa and B. vistulensis. However, the species concept differs from that applied by Schulz (1979). As a consequence, the stratigraphic ranges of these species are modified. Four species are left in open nomenclature and represent possibly new species. Future studies may reveal that they might be assigned to East European forms from Ukraine or Russia. The species of Belemnella recognized are placed into the stratigraphic framework based on the standard ammonite and inoceramid bivalve zonations, especially those recognized in the Vistula section. The newly proposed belemnite zonation for the Vistula and Kronsmoor sections is correlated via inoceramids with the standard GSSP at Tercis, France, in order to identify the base of the Maastrichtian Stage. The Campanian/Maastrichtian boundary as defined in Tercis is placed here at the base of the newly defined B. obtusa and B. vistulensis Zones ["obtusa/vistulensis"] - thus it is markedly higher than the traditional boundary based on the FAD of representatives of the genus Belemnella - This new boundary coincides well with a distinct turnover of belemnite guard morphology and represents one of the most important points in the early evolutionary history of Belemnella. Three belemnite zones defined by their lower boundaries are recognized in the Campanian/Maastrichtian interval, in addition to three subzones recognized within the B. obtusa Superzone. The B. lanceolata and B. inflata zones as understood here are referred to the Upper Campanian [Tercis definition]. The B. obtusa Zone is subdivided into three subzones, viz.: Belemenlla vistulensis, Belemnella sp. G and Belemnella sp. F, which are referred to the Lower Maastrichtian [Tercis definition]. The fast evolving species of Belemnella enable the proposal of a biostratigraphic scheme with a resolution that is higher than those based on inoceramid bivalves and ammonites - the longevity of a belemnite zone could be as low as 200Ky.
Źródło:
Acta Geologica Polonica; 2012, 62, 4; 495-533
0001-5709
Pojawia się w:
Acta Geologica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
New lissamphibians and squamates from the Maastrichtian of Hateg Basin, Romania
Autorzy:
Folie, A
Codrea, V.
Powiązania:
https://bibliotekanauki.pl/articles/23380.pdf
Data publikacji:
2005
Wydawca:
Polska Akademia Nauk. Instytut Paleobiologii PAN
Tematy:
Lacertilia
Romania
Anura
Allocaudata
lissamphibian
squamate
Hateg Basin
Maastrichtian
paleobiogeography
Opis:
Numerous remains of amphibians and squamates were discovered in the continental sediments of the Maastrichtian Sânpetru Formation, south of Pui Village (Haţeg Basin, western Romania). The lissamphibians are represented by a salamander−like allocaudatan (Albanerpeton sp.) and at least two discoglossid frogs (cf. Eodiscoglossussp. and cf. Paradiscoglossussp.). The numerous lizards are represented by, e.g., the teiid Bicuspidon hatzegiensissp. nov., and for the first time in a Late Cretaceous site, by two species of the paramacellodid Becklesius (Becklesius nopcsai sp. nov. and Becklesius cf. B. hoffstetteri). Snakes are also present in this site by an indeterminante madtsoiid, which represents the first occurrence of this family in eastern Europe. The presence of Albanerpeton in this site confirms that this genus appeared in Europe by at least the Late Cretaceous instead of Miocene as previously thought. The presence of both Albanerpeton and Bicuspidon in Haţeg Basin suggests a North American influence on eastern European amphibian and lacertilian faunas by Maastrichtian times.
Źródło:
Acta Palaeontologica Polonica; 2005, 50, 1
0567-7920
Pojawia się w:
Acta Palaeontologica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
First known gigantic sea turtle from the Maastrichtian deposits in Egypt
Autorzy:
Abu El-Kheir, G.A.-M
Abdelgawad, M.K.
Kassab, W.G.
Powiązania:
https://bibliotekanauki.pl/articles/2082330.pdf
Data publikacji:
2021
Wydawca:
Polska Akademia Nauk. Instytut Paleobiologii PAN
Tematy:
Testudines
Panchelonioidea
Cheloniidae
humerus
Cretaceous
Maastrichtian
Dakhla
Abu Minqar
Egypt
Opis:
The Maastrichtian deposits in Egypt and generally in Africa contain very few records of chelonioids. This scarcity hinders understanding the evolution and extinction of African chelonioids during this age. The Dakhla Basin in Egypt presents excellent Maastrichtian outcrops that consist of highly fossiliferous, calcareous siltstone and sandstone layers rich in ammonites, bivalves (Exogyra overwagi, Pycnodonta vesicularis, pectinids), gastropods, echinoids, corals, fossilized fruits of mangrove plants (Nypa) and vertebrate remains. The well-preserved humerus of giant turtle and other vertebrate remains have been discovered in the early late Maastrichtian Ammonite Hill Member of the Dakhla Formation in the Abu Minqar area, Southern Western Desert, Egypt. The Ammonite Hill Member was deposited in very shallow coastal, inner neritic to littoral environments. The well-preserved giant humerus represents the first record of gigantic Mesozoic chelonioids in Africa and the second record of chelonioids in the Maastrichtian deposits in Egypt. The present specimen contributes to fill the missing gaps in the history of Egyptian turtles from the Cretaceous through the Cenozoic.
Źródło:
Acta Palaeontologica Polonica; 2021, 66, 2; 349-355
0567-7920
Pojawia się w:
Acta Palaeontologica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Late Cretaceous foraminiferids from sections in the Zabratówka area (Skole Nappe, Outer Carpathians)
Autorzy:
Kowalczewska, O.
Gasiński, A.
Powiązania:
https://bibliotekanauki.pl/articles/191830.pdf
Data publikacji:
2018
Wydawca:
Polskie Towarzystwo Geologiczne
Tematy:
Foraminiferids
palaeobathymetry
Late Cretaceous
Maastrichtian
Skole Nappe
Ropianka Formation
Outer Carpathians
Opis:
Well preserved Late Cretaceous–Palaeogene planktonic and benthic foraminiferal assemblages were studied in the Zabratówka section of the Ropianka Formation in the Skole Nappe. The Racemiguembelina fructicosa and Abathomphalus mayaroensis standard foraminiferal biozones were distinguished. The K-T boundary was recognized within the interval between samples ZB10B–ZB9A, mainly composed of marly mudstones, interlayered with thin-bedded sandstones, and is characterized by the disappearance of planktonic taxa and an abundance of agglutinated species. Foraminiferal assemblages, collected from the turbiditic flysch-type sediments, indicate a primary depositional environment on the outer shelf to the upper part of the continental slope, with shallowing during the Maastrichtian in the part of the Skole Basin studied. The foraminiferids correspond to the assemblages of a palaeobiogeographical “transition” zone, located between the Boreal and Tethyan domains.
Źródło:
Annales Societatis Geologorum Poloniae; 2018, 88, 1; 71-85
0208-9068
Pojawia się w:
Annales Societatis Geologorum Poloniae
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Maastrichtian climate changes : the calcareous nannofossil record from flysch deposits of the Outer Carpathians
Autorzy:
Wierzbicki, Adam
Kędzierski, Mariusz
Powiązania:
https://bibliotekanauki.pl/articles/1836252.pdf
Data publikacji:
2020
Wydawca:
Polskie Towarzystwo Geologiczne
Tematy:
Late Maastrichtian warming
Deccan traps
K-Pg boundary
biostratigraphy
Skole Nappe
Opis:
The Outer Carpathians are known for a few sections, where transitions from the Upper Cretaceous to the Palaeogene, including the K-Pg boundary interval, were described. One of them, the Bąkowiec section in the Skole Nappe, was examined with reference to the record of biostratigraphy and palaeoenvironmental changes, mainly based on the analysis of calcareous nannofossil assemblages. This study shows no evidence for the K-Pg boundary; however, the presence of the nannofossil species Micula prinsii, marking the topmost Maastrichtian UC20dTP Zone, was noted. The appearance of this low-latitude taxon and relevant changes in the composition of nannofossil assemblages indicate an influx of Tethyan warm water into the northern Carpathian basins during the latest Maastrichtian, shortly before the K-Pg boundary event. Therefore, the authors infer that the upper part of the Bąkowiec section recorded the latest Maastrichtian warming of climate, probably triggered by Deccan volcanic activity.
Źródło:
Annales Societatis Geologorum Poloniae; 2020, 90, 4; 447-462
0208-9068
Pojawia się w:
Annales Societatis Geologorum Poloniae
Dostawca treści:
Biblioteka Nauki
Artykuł

Ta witryna wykorzystuje pliki cookies do przechowywania informacji na Twoim komputerze. Pliki cookies stosujemy w celu świadczenia usług na najwyższym poziomie, w tym w sposób dostosowany do indywidualnych potrzeb. Korzystanie z witryny bez zmiany ustawień dotyczących cookies oznacza, że będą one zamieszczane w Twoim komputerze. W każdym momencie możesz dokonać zmiany ustawień dotyczących cookies