Temat: Cretaceous - Prolib Integro

Skocz do pozycji: 1.

Tytuł:: A relict stem salamander: evidence from the Early Cretaceous of Siberia
Autorzy:: Skutschas, P.P.
Tematy:: relict
salamander
evidence
evolution
Early Cretaceous
Cretaceous
Siberia; Pokaż więcej
Wydawca:: Polska Akademia Nauk. Instytut Paleobiologii PAN
Powiązania:: https://bibliotekanauki.pl/articles/20727.pdf Link otwiera się w nowym oknie
Opis:: The early evolution of salamanders, which are one of the three living groups of lissamphibians, is not well known. Both stem- and crown-group salamanders first appeared in the Middle Jurassic (Bathonian), but subsequently had different evolutionary histories: stem salamanders were thought to have gone extinct in the Late Jurassic, while crown salamanders persist to the present day. Here, I report the discovery of an indeterminate stem salamander in the Lower Cretaceous (Aptian–Albian) Ilek Formation of Western Siberia. This is new evidence that the most basal salamanders survived beyond the Jurassic–Cretaceous boundary and co-existed with crown-group salamanders during approximately the first 40 million years of the known history of salamanders. The recognition of stem salamanders in the Early Cretaceous of Western Siberia adds to the inventory of taxa that suggest this area was a refugium for various groups of vertebrates with Jurassic affinities.
Dostawca treści:: Biblioteka Nauki

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Tytuł:: West to East in the Cretaceous – Greenhouse climate events and sea-level change
Autorzy:: Wagreich, Michael
Tematy:: Cretaceous
climate; Pokaż więcej
Wydawca:: Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie. Wydawnictwo AGH
Powiązania:: https://bibliotekanauki.pl/articles/24202102.pdf Link otwiera się w nowym oknie
Opis:: The Cretaceous greenhouse climate interval was characterized by intervals of extreme hothouse climate that lead to environmental Earth System events like the Oceanic Anoxic Events. In addition, the potentially ice-free hothouse, besides high magmatic activity due to final Pangaea breakup, fostered maximum sea-level with prolonged highstands more than 250 m above today’s sea level. The mid-Cretaceous interval, between OAE 1a (early Aptian) and OAE 2 (late Cenomanian), constitutes the time of most pronounced hothouse intervals leading to (nearly) global OAEs due to eutrophication of oceans, plankton blooms, expansion of oxygen minimum zones up to the photic zone, and down to the deep-sea bottom. This resulted regionally in black shale deposition and a minor extinction event of e.g. about 25% of planktic foraminifera. Taking OAE 2 as a case study, which constitutes the Cretaceous Thermal Maximum interval of at least more than 30–35°C equatorial ocean surface temperatures, high-precision stratigraphy based on cyclostratigraphy, astrochronology and numerical dating, a 300 to 700 ka OAE carbon isotope excursion interval can be reconstructed, ending in a recovery phase up to 1 Ma. Cyclostratigraphy results in 100 ka and 405 ka eccentricty signals, most significant in Tethyan areas and other lower latitude realms. Obliquity signals may be present in higher latitudes and may relate to higher precipitation, humid-arid and megamonsoon cycles. However, also during OAE 2, a significant cooling event, the Plenus Cold Event, is present, and may have resulted in intermittent ice shields on Antarctica. This cold snap is still represented in southern Tethys sections such as Tunisia based on stable isotopes and faunal migrations. Climate and temperature-have driven eustatic sea-level fluctuations, modulating the high sea level of the Cretaceous resulting from magmatic processes. During ice-free hothouse times, aquifer eustasy was the main process driving global sea level, at least on an amplitude of 30–50 m. Intermittent ice shields may conteract aquifer eustasy with higher magnitude glacial eustasy during cooler greenhouse phases like the Plenus Cold Event, but this is still under exploration. Major hothouse sea-level cycles have a cyclicity of about 1–1.2 Ma, showing precession- and eccentricity-modulated long-obliquity cycles in pelagic and shallow-water successions. This builds the basic sequence stratigraphy cycles during prominent greenhouse intervals of the Earth system, at least during the Mesozoic. Linking such greenhouse times models to our Anthropocene warming planet indicates a stronger hydrological cycle during warming and rising sea-levels.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 3.

Tytuł:: Origin and significance of Late Cretaceous bioevents: Examples from the Cenomanian
Autorzy:: Wilmsen, M.
Tematy:: Late Cretaceous
Cretaceous
bioevent
Cenomanian
paleontology
correlation
stratigraphy
Europe; Pokaż więcej
Wydawca:: Polska Akademia Nauk. Instytut Paleobiologii PAN
Powiązania:: https://bibliotekanauki.pl/articles/22376.pdf Link otwiera się w nowym oknie
Opis:: Palaeontological events, documented by widespread beds or thin intervals of strata with either unusual (“exotic”) or acmes of common faunal elements are a characteristic feature of Upper Cretaceous epicontinental shelf sediments in NW Europe. Their importance in stratigraphic calibration has early been recognized and these “bioevents” are widely used as correlation tools. Furthermore, it appears that there is a genetic link between sequence and event stratigraphy as most of the “classic” bioevents developed during specific intervals of a 3rd−order depositional sequence. Early transgressive bioevents (ETBs) are subdivided into two subtypes, i.e., the lag and migration subtype. The lag subtype corresponds to the transgressive surface and develops in response to winnowing and relative enrichment of robust biogenic hardparts. Taphonomic alteration and time−averaging are important features. The migration subtype is related to the disappearance of physical or ecological barriers that triggered faunal migrations. Despite their onlapping character, most ETBs are quasi−isochronous, and their preservation potential is usually high. Thus, they are very useful stratigraphic markers. Maximum flooding bioevents (MFBs) represent autochthonous biogenic concentrations with relatively low shell densities. They are related to habitat stability and ecospace expansion, and develop by population blooms of taxa well adapted to the special maximum flooding conditions of the wide epicontinental shelf of NW Europe (e.g., low food availability). Cenomanian MFBs of NW Europe are not time−averaged and may comprise stratigraphically more expanded intervals with gradational lower and upper boundaries. Their often wide palaeogeographic extent associated with very high chances of preservation results in an excellent inter−basinal correlation potential. Late highstand bioevents (LHBs) are local to regional shell concentrations deposited as a result of increasing winnowing of fines and reworking by storms, currents and waves during late highstands. LHBs usually consist of paucior even monospecific skeletal concentrations with a high degree of fragmentation. Simple shell beds related to a single (storm) event, and composite (multiple−event) shell beds are recognized. LHBs share some features of ETBs, but lack of time−averaging, are laterally restricted and have low preservation potential. Thus, their importance in interbasinal correlation is poor. The time scales of Cenomanian bioevents range through several orders of magnitude (hours–days in LHB storm event concentrations to ~100 kyr in MFBs). In terms of position within sequences, the three bioevent types correspond to shell concentrations recognized in Mesozoic–Cenozoic formations around the world. Shell beds with similar positions within cycles as well as comparable sedimentologic and taphonomic characteristics have also been described from high−frequency sequences and parasequences, suggesting that the formational processes of shell beds operate in base−level controlled sedimentary cycles of different hierarchies (i.e., 3rd−up to 7th−order).
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 4.

Tytuł:: Late Cretaceous gastropod egg capsules from the Netherlands preserved by bioimmuration
Autorzy:: Zaton, M.
Taylor, P.D.
Jagt, J.W.M.
Tematy:: Late Cretaceous
gastropod
egg capsule
Netherlands,The
bioimmuration
Cretaceous
paleontology; Pokaż więcej
Wydawca:: Polska Akademia Nauk. Instytut Paleobiologii PAN
Powiązania:: https://bibliotekanauki.pl/articles/21441.pdf Link otwiera się w nowym oknie
Opis:: Clusters of gastropod egg capsules, inferred to be of neritoids and attached to the inner shell wall of the ultimate whorl of a large volutid gastropod, are here recorded from the upper Nekum Member (Maastricht Formation; late Maastrichtian) of the ENCI−Heidelberg Cement Group quarry, St Pietersberg (Maastricht, southeast Netherlands). Because the aragonitic shell of the volutid has dissolved, the outlines of the egg capsules are now revealed on the steinkern of indurated biocalcarenite, having been subsequently overgrown by cheilostome bryozoan colonies and preserved as mould bioimmurations. This represents the first example of gastropod eggs preserved through bioimmuration, as well as the first record of gastropod eggs from the Cretaceous.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 5.

Tytuł:: A silicified wood from the Early Cretaceous sediments in the Kaligandaki Valley, west central Nepal
Autorzy:: Paudayal, Khum N.
Paudel, Lalu P.
Uhl, Dieter
Tematy:: Tethys
Cretaceous
Nepal; Pokaż więcej
Wydawca:: Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie. Wydawnictwo AGH
Powiązania:: https://bibliotekanauki.pl/articles/24202093.pdf Link otwiera się w nowym oknie
Opis:: A silicified wood has been discovered from the Tethyan Cretaceous (Berriasian) deposits belonging to the Kagbeni Formation of north Central Nepal. The wood exhibits anatomical features which are well in accordance with Araucarioxylon nepalense described by Barale et al. (1976) from another locality in the Kagbeni Formation near Kagbeni in the Thakkhola Valley in Central Nepal. It is a pycnoxylic wood with mostly uniseriate and rarely biseriate bordered pits on radial tracheid walls. According to recent taxonomic opinions this type of wood should not be treated as Araucarioxylon, but as Agathoxylon Hartig. Thus we propose the name Agathoxylon nepalense comb. nov. for this type of wood. The sandstones of the Kagbeni Formation have been interpreted as delta-deposits, with a major flow direction from the south. This suggests that the wood originated from the northern margin of Indian sub-continent.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 6.

Tytuł:: The earliest Cretaceous carbonate platform destroyed by volcanism from the Ukrainian/Romanian Carpathians – reconstruction based on microfacies
Autorzy:: Iwańczuk, Joanna
Krobicki, Michał
Feldman-Olszewska, Anna
Hnyłko, Oleh
Tematy:: Carpathians
Cretaceous
carbonate; Pokaż więcej
Wydawca:: Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie. Wydawnictwo AGH
Powiązania:: https://bibliotekanauki.pl/articles/24202094.pdf Link otwiera się w nowym oknie
Opis:: There is a unique tectonostratigraphic unit called Kaminnyi Potik occur in the Ukrainian-Romanian Carpathian transborder zone. In the Ukrainian part numerous outcrops of this unit can be observed in many streams near Rachiv city, but its most spectacular occurrence is in the Chyvchyn Mountains. The whole complex consists of volcanogenic-sedimentary rocks and is divided into two Berriasian formations: Chyvchyn and Kaminnyi Potik. In the section of the Chyvchyn Formation, at the base, there are pillow lavas (basalts and andesites/trachyandesites) and volcano-sedimentary breccia with clasts of lava, coral limestones and radiolarites (submarine debris flows), and peperites as well. The Kaminnyi Potik Formation is made up of fine-grained hyaloclastic and carbonate debris flows of a flysch character (including organodetrital limestones with fragments of: corals, bryozoans, echinoderms bivalves and foraminifera), which overlying breccias and coral limestones of the Chyvchyn Formation. The profile ends by thin-bedded cherty limestones. The thin sections analysis revealed the following microfacies: oolithic-echinoderm packstone/grainstone; coral lithoclastic quartz packstone/grainstone; oolithic-lithoclastic wackestone/packstone; lithoclastic-echinoderm packestone; lithoclastic packestone; radiolarian echinoderm packestone; radiolarian wackestone; radiolarian-calpionellid wackestone and mudstone. Pyroclastic material is often present in the matrix. The ooids observed in the thin sections and the remains of fauna such as corals, echinoderms and bivalves suggest that the original material came from a carbonate platform that was sheltered by a coral reef. As a result of volcanic eruptions and possibly accompanying earthquakes, the platform has been destroyed and its traces are visible in clasts. Sedimentological character of submarine debris flows, (e.g. fractional graiding, mixture of shallow-water fauna and lithoclasts with deep-marine microfauna (radiolarians and calpionellids) and hyaloclastic material present in the matrix document short-term episodes of a catastrophic nature, leading to the redeposition of shallow-water sediments to the deeper parts of the basin.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 7.

Tytuł:: Jurassic and Cretaceous evolution of Tethys: Palaeoceanographic events
Autorzy:: Yilmaz, İsmail Ömer
Tematy:: Tethys
Cretaceous
Jurassic; Pokaż więcej
Wydawca:: Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie. Wydawnictwo AGH
Powiązania:: https://bibliotekanauki.pl/articles/24202104.pdf Link otwiera się w nowym oknie
Opis:: Jurassic and Cretaceous evolution of Tethys Ocean is characterized by extension of oceans basins, rifting, development of carbonate platforms and sea level fluctuations. Ocean basins and platform margins were sides of records of collaboration of oceanic, sea level and climate changes in different scales. Deposition of organic sediment increased on the margins of the ocean basins at certain time intervals due to changes in oceanic circulation and chemistry, productivity, climate and sea level. Oceanic Anoxic Events (OAE) stated to took place at aperiodic time intervals and generally associated with organic matter deposits and anoxic water columns. Records of oceanic anoxic event can also be associated by potential source rocks in Jurassic and Cretaceous along Tethys Ocean basins and can be tracked by stable isotope shifts, turnover of fossil groups, presence of black shales/organic rich mudstones, change in redox sensitive elements. Volcanic contribution in oceans is also considered as one of the collaborators of OAE generations. OAE records in Jurassic is seen in Toarcian interval and stated as Toarcian OAE. In Cretaceous, OAE records can be stated as Weissert, Faraoni, Selli (OAE1a), Noir, Fallot, Jacop, Kilian, Paquier (OAE1b), Leenhardt, Amadeus (OAE1c), Breistroffer (OAE1d), Bonarelli (OAE2), and OAE3. Generally, Cretaceous OAE are globally correlated or at least hemispherical. Some of them can be weakly correlated due to different duration and magnitude. Stratigraphic positions of OAE can also be used better marker levels in sequence stratigraphic interpretations. Therefore, positions of OAE are very important in terms of higher resolution for platform to basin correlations and even basin to basin. Cretaceous Oceanic Anoxic Events in eastern Tethys Ocean in Pontides and Taurides can be seen in Cretaceous successions (Mid-Barremian, Aptian, Albian, Cenomanian-Turonian) of Central Pontides (NW Turkey) and Central Taurides (S Turkey) (Yilmaz et al., 2004, 2010, 2012) as presence of black shales. The Mid-Barremian black shales (MBE) have been recorded within turbidite succession in deep marine setting in central Sakarya zone of Pontides following the drowning of the platform (Yilmaz et al., 2012). 2‰ shifts in carbon isotope curve is recorded in parallel with European basins, but with low TOC value. The Aptian black shales (OAE1a) are recorded in pelagic carbonate slope environments in central and north of Sakarya zone of Pontides and represented by a negative carbon isotope shift with 2‰, and TOC around 2% (Yilmaz et al., 2004; Hu et al., 2012). In Sakarya zone of Pontides, OAE2 is recorded in pelagic slope carbonates with carbon isotope curve more than 1‰ positive shift and >2% TOC. Another OAE2 was recorded in Antalya Nappes of Taurides without carbon isotope curve but TOC > 20% (Yurtsever et al., 2003, Bozcu et al., 2011). OAE1a equivalent in Tauride Carbonate platform can be interpreted as presence of dark colored thick stromatolite bearing platform carbonates transgressivley overlying the karstic sequence boundary. The OAE1a and OAE2 levels recorded in Turkey can easily be correlated with European examples and mainly controlled by sea level and tectonics in largescale and climate and oceanographic changes in small-scale. The most extensive distribution of the OAE records in Turkey belong to OAE1a and OAE2, and display potential for source rocks for hydrocarbon exploration.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 8.

Tytuł:: The oldest Brazilian snakes from the Cenomanian (early Late Cretaceous)
Autorzy:: Hsiou, A.S.
Albino, A.M.
Medeiros, M.A.
Santos, R.A.B.
Tematy:: paleontology
Reptilia
Squamata
Ophidia
snake
Cenomanian
Late Cretaceous
Cretaceous
Brazil; Pokaż więcej
Wydawca:: Polska Akademia Nauk. Instytut Paleobiologii PAN
Powiązania:: https://bibliotekanauki.pl/articles/945877.pdf Link otwiera się w nowym oknie
Opis:: South American Mesozoic snake diversity is mostly represented by genera from the Cenomanian (Najash), Santonian–Campanian (Dinilysia), and Campanian–Maastrichtian (Alamitophis, Patagoniophis, Rionegrophis, and Australophis) of Patagonia, Argentina. In this paper, we describe a new snake genus and species, Seismophis septentrionalis, from the Cenomanian (early Late Cretaceous) of the Alcântara Formation, Maranhão, northeastern Brazil. The new snake comprises a posteriormost trunk vertebra and possibly a poorly preserved midtrunk vertebra. Both vertebrae share small size, zygosphene moderately thick with a rectilinear roof, absence of paracotylar foramina, presence of parazygantral foramina, and strongly marked parasagittal ridges of the neural arch. The new snake is here considered of uncertain systematic affinities, but probably close to the limbed snake Najash rionegrina. Although the material is very fragmentary and the systematic assignment is still unresolved, this snake represents the oldest, as well as probably the most primitive snake from Brazil.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 9.

Tytuł:: New data on anatomy of the Late Cretaceous multituberculate mammal Catopsbaatar
Autorzy:: Kielan-Jaworowska, Z
Hurum, J.H.
Currie, P.J.
Barsbold, R.
Tematy:: mammal
Cretaceous
Late Cretaceous
anatomy
Catopsbaatar catopsaloides
Catopsbaatar
multituberculate mammal; Pokaż więcej
Wydawca:: Polska Akademia Nauk. Instytut Paleobiologii PAN
Powiązania:: https://bibliotekanauki.pl/articles/19969.pdf Link otwiera się w nowym oknie
Opis:: The Gobi Desert is famous for providing one of the worlds best preserved Cretaceous terrestrial faunas, including dinosaurs and mammals. Beginning with the Central Asiatic Expeditions in the 1920s, through the Polish−Mongolian Expeditions in the 1960s–1970s, Soviet−Mongolian Expeditions in 1970s, and finally the Mongolian Academy−American Museum Expeditions in the 1990s–2000s, the number of complete skulls (see Kielan−Jaworowska et al. 2000 for review) of Cretaceous mammals often associated with postcranial skeletons, found in Mongolia increased to several hundred. In addition to these professional expeditions, there have been other types of trips to Mongolia, also aimed at collecting fossils. The Nomadic Expeditions Company in USA organizes one of these, and has made trips to Mongolia since 1996. During the 1999 Nomadic Expedition, a skull associated with parts of the postcranial skeleton of the multituberculate mammal Catopsbaatar catopsaloides was found. The specimen is more complete than others previously known of this species and brings new data on multituberculate anatomy and ontogenetic variation. In this note we discuss the new data on the structure of C. catopsaloides; the details of its anatomy will be described in subsequent papers by the two first authors.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 10.

Tytuł:: The Upper Cretaceous Ostreidae from the Middle Vistula Region (Poland)
Ostrygi górnokredowe z przełomu środkowej Wisły (Polska)
Ustricy verkhnego mela iz rajjona Central’nojj Visly (Pol’sha)
Autorzy:: Pugaczewska, H.
Tematy:: paleontology
Cretaceous
Upper Cretaceous
Ostreidae
ostreid
shell
Vistula River
Polska; Pokaż więcej
Wydawca:: Polska Akademia Nauk. Instytut Paleobiologii PAN
Powiązania:: https://bibliotekanauki.pl/articles/22524.pdf Link otwiera się w nowym oknie
Dostawca treści:: Biblioteka Nauki

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