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1.
Organic dinoflagellate cysts are studied from the sedimentary sequence of hole 1-SPS-14A, drilled during oil exploration in the Santos Basin, Brazilian continental margin. The Ariri and Florianópolis Formations (Transitional sequence) do not contain any dinocysts. The oldest found dinocysts occur at the base of the Drift sequence in sediments, within platform carbonates of the Guarujá Formation. Continuous sea-level rise throughout the late Albian and Cenomanian submerged the carbonate platform with the terrigenous input of the Itanhaém Formation. The transgressive phase reached its peak during the Cenomanian/Turonian transition. Pelites were deposited during oceanic anoxic event (OAE-2), consisting the lower part of the Itajaí-Açu Formation. Normal oceanic conditions re-established in the late Turonian. The Brazilian dinocyst assemblage has tethyan affinities. Some species (i.e., Dinopterygium cladoides, Litosphaeridium arundum, Odontochitina rhakodes and Systematophora cretacea) suggest a middle Albian age for the carbonate platform of the Guarujá Formation. The lower part of the Guarujá Formation was not dated by other microfossils. An uppermost Albian or lower Cenomanian age is suggested for the base of the Itanhaém Formation on the basis of species Palaeohystrichophora infusorioides and Ovoidinium verrucosum. The Cenomanian-Turonian boundary cannot be characterized by dinocysts. Species Atopodinium iuvene, which is known from Turonian sediments in Europe, was found at the top of the Itajaí-Açu Formation. The observed dinocyst bioevents (i.e., last occurrence) are correlated with known foraminiferal, nannofossil and other palynological bioevents. The diversity of the assemblages remains constant throughout the various palaeoenvironments as these are reflected by the Guarujá and Itajaí-Açu Formations, but relative abundances of taxa are variable. Genera Coronifera, Florentinia, Ovoidinium, Spiniferites and Trichodinium are abundant in the carbonate platform assemblages (Guarujá Formation). Genera Cribroperidinium and Cyclonephelium are abundant in detrital sediments (Itajaí-Açu Formation). Only one species (Subtilisphaera guarujaensis n. sp.) is restricted to the carbonate platform environment.  相似文献   

2.
Theropod teeth from the Bajo Barreal Formation (Upper Cretaceous: Cenomanian-Turonian) at the “estancia Ocho Hermanos”, Chubut Province are described. Most of them show features of Abelisauroidea, a clade already represented in the Bajo Barreal Formation by Xenotarsosaurus bonapartei and other isolated remains including a left maxilla. Dromaeosauridae and Carcharodontosauridae represent the first record of these taxa for the Bajo Barreal Formation. Besides this, at least three theropod clades (Abelisauroidea, Carcharodontosauridae, and Dromaeosauridae) coexisted in central Patagonia during the Cenomanian-Turonian along with other theropods as Aniksosaurus darwini and Megaraptor sp.  相似文献   

3.
《Annales de Paléontologie》2017,103(3):185-196
In the southwestern part of Algeria, the Cenomanian-Turonian marine deposits build up a prominent ledge in a perched syncline (Ksour Mountains, western Saharan Atlas) or at high radius of curvature (Guir Basin). The petrographical analysis of the Cenomanian-Turonian deposits of the Ksour Mountains and of the Guir Basin reveals unexpected assemblages of roveacrinoidal ossicles comparable with those formerly reported from the Tinrhert area. For the first time, isolated ossicles of genuine and undisputable Roveacrinidae are illustrated. Three sections, Djebel Rhoundjaia (western Saharan Atlas), Berridel and Kénadsa (Guir Basin), were scrutinized to recognize the microcrinoidal sections within the carbonate microfacies and to compile the successive occurrence of respective roveacrinid taxa (besides the classical search for standard index microfossils) in an attempt to pinpoint more precisely the position of the Cenomanian-Turonian boundary (C/T B). These assemblages are particularly morphologically and taxonomically diverse with three species of genus Roveacrinus and one of genus Orthogonocrinus. The presence of Saccocomidae (Applinocrinus) is especially unusual in such stratigraphic levels. The relative abundance and diversity of Roveacrinidae evidence a peak when approaching the C/T B. Such an event is recurring in the latest Cenomanian in various Tethyan and Atlantic areas. These fluctuations are consistent with a high surface-water productivity just before the C/T B.  相似文献   

4.
The rugose coral genusAmplexocarinia Soshkina, 1928 is recorded for the first time from the Freilingen Formation (Upper Eifelian) of the Sotenich syncline (North Eifel, Rheinisches Schiefergebirge). A new species,Amplexocarinia freilingensis, is described, figured and compared toAmplexocarinia sp. from Eifelian/Givetian boundary beds of Moravia (Czechoslovakia) and to similar forms from different Devonian strata. Some remarks concerning the stratigraphy of the Freilingen Formation of the Sotenich syncline are given.  相似文献   

5.
A biostratigraphic study of dinoflagellate cysts of the Upper Jurassic series from the eastern External Rif Chain, has been achieved for the first time on four outcrop sections : the DM section (Douar Marticha), the TB section (the Tarhchenna “Sof”), the KSD section (the Kef Mallou “Sof”) and the Y section (Douar Lamriene) among which three sections (TB, KSD and Y) are well-dated by ammonites and calpionellids fauna. The DM and TB sections are complementary in terms of stratigraphy and correspond respectively to the upper part of the “Ferrysch” Formation, a thick shaly–silty and sandy sequence assigned to the Callovian-Oxfordian stages and to the El Gouzat limestones Formation (Kimmeridgian - Lower Tithonian age) and to the Tarhchenna marly limestones Formation (Upper Tithonian age) from the EL Gouzat area (Mesorif). The KSD and Y sections are also complementary and correspond to the Kimmeridgian-Lower Tithonian Msila limestones Formation and to the overlying marly limestones Massif Formation of Upper Tithonian age, outcropping in the Msila region (Internal Prerif). These four sections have shown many dinocysts rich levels, which had allowed characterizing the Middle? and Upper Oxfordian substages in the DM section. In the other sections, the dinoflagellate cyst assemblages are nearly similar to those of the Kimmeridgian–Tithonian of many sections from the Boreal, Sub-boreal and North tethyan realms, particularily from England, Russia and South-East France basin. The results of the present work confirm once again, the important value of dinoflagellate cysts, for age dating of ammonites-lacking Mesozoic sedimentary sequences and for biostratigraphic correlations.  相似文献   

6.
The lithostratigraphy and biostratigraphy of the Paleocene and Eocene formations have been reconsidered on the basis of 18 dated boreholes that intersect the Basque Country, Peyrehorade, Sainte-Suzanne and Sauvelade allochthonous tectonic units, as well as the autochthonous units of the Pey-Saint-Lon anticline, the Arzacq Basin and the North Pyrenean Trough. Correlation of the formations identified in the boreholes and at outcrop has made it possible to outline the sedimentary evolution of this region during the Early Paleogene and to date the various stages of Pyrenean compression on the basis of sedimentary gaps and syntectonic detrital input. The Lasseube Formation is present over the entire study area. Sedimentation becomes differentiated during the Late Selandian-Early Ypresian period. In the North Pyrenean Trough and in the Peyrehorade, Sainte-Suzanne and Sauvelade units, the detrital-clayey Pont-Labau Formation is well developed and all its members are represented (Guillempau, Latapy, Néez, Libaros and Artigueloutan; zones upper P 3b-P 6b; upper NP 5-NP 11). A sedimentary gap showing erosion, and involving zones upper P 3b-upper P 4a and upper NP 5-NP 7, characterises the Basque units, the Pey-Saint-Lon anticline and the western part of the Arzacq Basin. Sedimentation recommences in zone P 8 with middle-bathyal deposits of the Cassoua Member and then continues with the Artigueloutan Member (transition facies towards the Louts Formation) or limestone resembling that of the Meilhan Formation. The Gan Formation shows an east-west polarity. In the east, between the Sainte-Suzanne Unit and the North Pyrenean Trough, the formation is argillaceous with a dominant neritic character, apart from a circalittoral to epibathyal passage in its lower part (zone P 7) containing numerous planktonic foraminifera. The formation is of a detrital and carbonate nature in the west (Sainte-Marie-de-Gosse 1). The bathyal Donzacq Formation appears to transgress a previously deformed surface. Two domains existed during the Lutetian: a continental to neritic domain in the south and a bathyal domain in the north (the Saint-Geours-d'Auribat and Miretrain formations) separated by a variably thick transition zone that is affected by thrust fronts. Two new formations - the Orthez and Sorde-l'Abbaye formations - are proposed, and the Marly limestone formation of Saint-Barthélémy (Douvillé, 1905) is redefined. The Orthez Formation (Sauvelade Unit) is composed of marl and continental conglomerate with neritic carbonate interbedding and belongs to the sub-zones NP 15a and b. The Sorde-l'Abbaye Formation (Peyrehorade Unit and the Basque units p. p.) is composed of neritic carbonate sediments (Lutetian-Priabonian). The Saint-Barthélémy Formation is made up of syntectonic conglomerate, turbiditic limestone and pelagic marl in the central part of the Basque units (NP 15a-NP 16). The Bartonian and Priabonian stages are characterised by carbonate sediments in the Arzacq Basin (Siest Formation). Its base is diachronous: Upper Lutetian (zone SB 16) in the east and Late Bartonian grading to Priabonian in the west (zones SB 17/18 and SB 19). The sediments are argillaceous (Côte des Basques Formation) along the Atlantic coast, in the central part of the Basque units and in the Bayonne-Cauneille syncline. Major thickness variations reflect tectonic phases at the top of the Lasseube Formation in the north (erosion pre NP 8), the Néez Member (NP 7/NP 8 boundary), the Artigueloutan Member (NP 11/NP 12 boundary), and the Gan Formation (P 8/P 9 boundary). The syntectonic conglomerate and breccia indicate the development of thrust fronts in the Libaros Member (NP 8), at the base of the Pillardou and Artigueloutan members (NP 9b, c-NP 10), in the Saint-Geours-d'Auribat Formation (NP 14b) and in the Orthez and Saint-Barthélémy formations (between zones NP 15a and NP 16).  相似文献   

7.
The stratigraphic review and the dating, by means of planktonic foraminifera (Globotruncanidae, Heterohelicidae, “Globigerinidae”), of the main marine Maastrichtian and Paleocene series deposited, in Bulgaria (Fore-Balkan and Luda Kamcija zone), within three paleogeographic domains (foreland turbiditic trough: Emine Formation; hemipelagic basin: Bjala Formation; external/distal-dominated carbonate platform: Mezdra Formation) allow to propose new correlations between the series of the different domains along the North-Tethyan margin. Several features characterize these series: absence of significant lithologic break between Maastrichtian and Danian deposits when they are represented; very local deposition of the Iridium-bearing dark clays underlining the K/T boundary; ponctual evidence of a gap, variable in duration, below and above this boundary (this gap is probably generated by extensional/compressional “laramian” tectonics); diachronism of the glauconitic condensation levels, more or less linked to hard-grounds, which are all included within Paleocene carbonate deposits, various in age, and are never situated at the K/T boundary.  相似文献   

8.
The Late Jurassic - Early Cretaceous series encountered in South-East Tunisia, formely considered globally as Purbecko-Wealdian in age, has the most complete palaeobotanical record of all North-Gondwana. Thanks to the stratigraphical results of the last years and to new field researches, it was possible, for the first time, to evidence an Oxfordian flora at the base of this series (Bir Miteur Formation). This flora, constituted of impressions and axes of Pteridophytes and Gymnosperms, is encountered within different types of plant-bearing levels. The study of deposit facies and sequential analysis of this Oxfordian formation allowed the identification of corresponding sedimentary environments and to infer their palaeoecological meaning. The discovery of exceptional specimens provided new informations about the general morpho-anatomy of Alstaettia, a very peculiar tree fern of a now extinct type. This Oxfordian flora is an interesting key-point in the evolution of North-Gondwanian flora at the Jurassic/Cretaceous transition.  相似文献   

9.
Well-preserved dinosaur eggs from the Cretaceous Huizhou Formation in the Xiuning Basin, Anhui Province, China, are analysed in this paper. We describe a new oospecies, Similifaveoloolithus qiyunshanensis, based on several distinct characters of external morphology, size, eggshell thickness, and internal microstructure. Radial sections of this new oospecies show branched eggshell units with a fused layer near the outer surface, while numerous irregular pores and cones constitute a honeycomb pattern in tangential sections. The discovery of S. qiyunshanensis expands the distribution of Similifaveoloolithidae dinosaur eggs in China and provides new fossils for researching dinosaur eggshell formation mechanisms which are different from those of the currently known oofamilies. The dinosaur-egg-bearing strata in the Huizhou Formation have been dated to the early Late Cretaceous (Cenomanian-Turonian) on the basis of a similar dinosaur egg assemblage in the Tiantai Basin in Zhejiang Province. The eggs described in this paper are thought to have been laid in a buried nest while enrichment of trace elements in eggshells may have been caused by their ingestion into the body of the dinosaur producer. We suggest that the paleoclimate of this habitat was semi-arid to arid and that this environment was favourable for the preservation of eggs.http://zoobank.org/LSIDurn:lsid:zoobank.org:pub:9D63A51F-5A4B-4249-901D-42A33E9FA933  相似文献   

10.
In Tunisia, in the platform domain, the Aptian-Albian transition is associated with a major stratigraphic gap not precisely dated, which is related to the subaerial exposure of the Aptian Orbata platform. Locally, in central Tunisia (Jebel Kebar), this gap is substituted by the sedimentary records of the Kebar Formation. This formation provided a rich association of fossil charophytes, formed by Atopochara trivolvis trivolvis, Clavator harrisii zavialensis and Sphaerochara verticillata which allows attributing it to the late Aptian–early Albian interval (most probably early Albian). In addition, a new variety, Sphaerochara verticillata var. kebariensis, is described. The charophyte assemblage shows significant biogeographic affinities with a coeval flora found in the Iberian Peninsula. The Kebar Formation was previously regarded as exclusively nonmarine, but the presence of the assemblage of charophytes and associated ostracods described rather indicates a fluctuation between margino-littoral (lagoonal) and continental environments.  相似文献   

11.
H Blom  & D Goujet 《Palaeontology》2002,45(4):795-820
Scales of nine thelodont taxa are described from the Red Bay Group of Spitsbergen, also characterized by its assemblage of other typical Early Devonian vertebrates. The four thelodont–bearing horizons of the lower Fraenkelryggen Formation yield typical Lochkovian thelodont assemblages, containing Boreania minima , Canonia grossi , Nikolivia depressa sp. nov., Nikolivia elongata , Nikolivia gutta and Turinia pagei . One horizon from the younger Ben Nevis Formation has a similar thelodont assemblage, except for two new taxa; Apalolepis angelica sp. nov. and Turinia barentsia sp. nov. The appearance of Turinia polita and the disappearance of Boreania minima is also characteristic for this assemblage. Comparison with similar faunas from the Northern Hemisphere supports this faunal change and allows further elaboration of Early Devonian thelodont biostratigraphy.  相似文献   

12.
An association of limnic ostracodes has been discovered in the upper part of the Irbzer Formation, of Maastrichtian age, in the Moroccan Middle-Atlas. A new species is described, Gomphocythere achloujensis nov. sp. Paracandona occitanica, which is very common in terminal Cretaceous non-marine deposits of southern Europe (France, Spain), is found for the first time on the south Tethyan margin.  相似文献   

13.
A microfauna composed of 11 species of ostracodes belonging to 11 genera have been recovered from the Bhanness Formation of Kimmeridgian age, in Central Lebanon. Four species are new and are described herein: Ektyphocythere dahressawanensis nov. sp., Dicrorygma (Orthorygma) libanensis nov. sp., Citrella? elongata nov. sp. and Procytherura inflata nov. sp. From a palaeobiogeographical standpoint, this fauna characterizes the North Gondwana province which differs from the South Gondwana province, particularly by the presence of the genus Schuleridea and the absence of the genus Majungaella.  相似文献   

14.
Gyrogonites of charophytes from two localities of the Oudiksou syncline (Middle Atlas, Morocco) are studied. The Irbzer formation in the Achlouj-2 site yielded charophytes (Feistiella oblonga, F. globosa, Strobilochara apiculata, S. diademata) that suggest a Campanian-Maastrichtian age; this result is consistent with all previously published biochronological studies. The overlying Bekrit-Timahdit formation, supposed to be Thanetian to Lutetian in age, without paleontological evidence, yielded charophytes in the Saf locality (Peckichara cf. llobregatensis, Feistiella sp. 1, Maedleriella sp.). This association indicates a Paleocene age for the middle member of this formation.  相似文献   

15.
The Nabeul-Hammamet series analysis allows to recognize the six biozona known in the Mediterranean realm, as specified by Cita (1975a). These are: the Sphaeroidinellopsis subdehiscens BANNER & BLOW acme biozone equivalent to MPL1; the Globorotalia margaritae margaritae BOLLI & BERMUDEZ interval zone (= MPL2); the Globorotalia margaritae BOLLI & BERMUDEZ, Globorotalia puncticulata (DESHAYES), concurrent range zone (= MPL3); the Sphaeroidinellopsis subdehiscens BANNER & BLOW interval zone (= MPL4); the Globigerinoides elongatus (D’ORBIGNY) interval zone (= MPL5); the Globorotalia inflata (D’ORBIGNY) interval zone (= MPL6). There is no similarity between these biozones and those established by Berggren and al. (1995) for the atlantic and the indo-pacific realms. The MPL1, MPL2, MPL3 and MPL4 zones are especially englobed in argillaceous and yellow sandy lithological units specified in north-eastern Tunisia, such as ‘Argiles des Potiers’, ‘Sables Jaunes de Nabeul’ and ‘Argiles de Sidi Barka’. These units are together equivalent to the Raf-Raf Formation developed towards the North, in the Bizerte area. Besides, the MPL5 and the MPL6 zones are included in sands and sandstones composing the Hammamet unit, equivalent to the Porto-Farina Formation.  相似文献   

16.
Broad bean wilt virus 1 (BBWV‐1) is transmitted by several aphid species in a non‐persistent manner. Transmission efficiency by vectors is a key factor for understanding virus epidemiology and applying disease control measures based on limiting virus spread. We evaluated the transmission rates of two genetically divergent BBWV‐1 isolates (PV‐132 from USA and Ben from Spain) infecting broad bean (Vicia faba L.) by isofemale lines of nine aphid species from eight different genera collected in Spain. Our analyses showed that: (a) the virus concentration in the source plant was a key factor in BBWV‐1 transmissibility; (b) The Spanish isolate Ben was transmitted more efficiently than the American isolate PV‐132 by most aphid species, but this was only due to the higher accumulation of Ben in plants, as both isolates had similar transmissibility after adjusting virus concentration and (c) The transmission rate varied greatly between the different aphid species.  相似文献   

17.
X Ma  W Li  H Yu  Y Yang  M Li  L Xue  T Xu 《Cell death and differentiation》2014,21(3):407-415
The TNF–JNK pathway is a highly conserved signaling pathway that regulates a wide spectrum of biological processes including cell death and migration. To further delineate this pathway, we carried out a genetic screen for dominant modifiers of the cell death phenotype triggered by ectopic expression of Eiger (Egr), the Drosophila TNF ortholog. Here we show that Bendless (Ben), an E2 ubiquitin-conjugating enzyme, modulates Egr-induced JNK activation and cell death through dTRAF2. Furthermore, Ben physically interacts with dTRAF2 and regulates Egr-induced dTRAF2 polyubiquitination. Finally, Ben is required for JNK-dependent tumor progression, cell migration, oxidative stress resistance and longevity. Our results indicate that Ben constitutes an essential component of the evolutionarily conserved TNF–JNK pathway that modulates cell death and invasion, tumor progression, stress response and lifespan in metazoans.  相似文献   

18.
In several synclines of the central High Atlas, the “Redbeds” following the closure of the marine Tethyan Atlasic trough during the Middle Jurassic are constituted by three successive formations or units of continental deposits dated recently with biostratigraphical elements. Some micropaleontological markers, mainly charophytes and ostracods, allow to precise the stratigraphy in agreement with a Bathonian-?Callovian assignment for the lower unit (Guettioua Formation), and in dating the middle and upper units. The Upper Jurassic, mainly the Kimmeridgian, is developed in the lower part of the middle unit (Iouaridene Formation). The Barremian has been recognized in this middle unit and in the upper unit (Jbel Sidal Formation). The Jurassic/Cretaceous boundary is thus delimited for the first time with micropaleontological data. These new data are very significant for the Atlasic history during the Mesozoic. The basaltic flows inserted in the continental Jurassic-Cretaceous deposits of the central High Atlas result from two separate events in the Middle Jurassic and in the Barremian. The tectogenesis in the basins is characterized by a polyphase process including notably a synsedimentary tectonic activity conspicuous in the Barremian. The evidence of marine to brackish intercalations allows moreover to date the first Cretaceous transgressive event on the NW boundary of the High Atlas during the Lower Barremian and to consider an Atlantic paleogeographical interaction. SW margin of the Tethyan trough in the Lower and Middle Jurassic, the central High Atlas is merged with the margin of the central Atlantic Ocean during the Lower Cretaceous.  相似文献   

19.
《Comptes Rendus Palevol》2016,15(5):461-471
Mesozoic strata of North Africa yield the first occurrence of the ichnogenus Selenichnites. The trace fossils occur on the top surface of a sandy carbonate deposit in the axis of a Middle Atlas syncline (Skoura Syncline, NE Morocco). The ichnofossil-bearing horizon belongs to the Late Bajocian–Early Bathonian Ich Timellaline/Bou Akrabene Formation. The trace fossils are crescent-shaped and the best preserved exhibits a posterior central axial impression (possible telson tail impression). They are interpreted as feeding burrows (fodinichnia) or hiding depressions of Xiphosurids or Limulids (horseshoe crabs) on a sandy carbonate substrate beneath a veneer of muddy deposits. The sedimentological character suggests a relatively protected shallow water subtidal palaeoenvironment preceding the Bathonian regression of the Atlas domain. This discovery provides the first evidence of xiphosurans or xiphosuran-like organisms inhabiting the southern shores of the Tethys in the Middle Jurassic.  相似文献   

20.
The amber of Le Mas d’Azil (Ariège, France), fashioned by the Magdalenian people of Le Mas d’Azil cave, was collected in clay levels rich in Cupressinoxylon Göppert, of the Campanian Labarre Sandstone Formation, which is a large deltaic set, infilling the sub-Pyreneean trough. The amber pieces are small and resemble modern resin exudates on coniferous trunks. We describe following micro-inclusions. Actinomycetes: Cardonia stellata, nov. gen., nov. sp., located close to the surface of amber pieces, is abundant and displays chains of conidia and isolated aleuriospore. Nocardiopsis ? sp. D is rare. Actinomycete “de type Salignac” is abundant. Its filaments often display a tendril shape, which seems to prelude to a mycelium fragmentation. Other bacteria: Leptotrichites resinatus Schmidt ( Schmidt and Schäfer, 2005), poorly represented, is more variable than the already known material; cf. Sphaerotilus sp., very abundant, also displays differences with the Cenomanian “Sphaerotilus sp.”. Eukaryotes: one fungal filament, and a group of spores, pollens or cysts. Inorganic inclusions: gas bubbles, pseudo-protists of B and C? types, and tiny, transparent, cubic crystals. It seems that most of the quoted prokaryotes were resinicolous organisms, able to settle on the surface of the exudate, and grow in the resin, after inoculation either by a contact with the substrate, or by an anemophilic dispersion of spores. This “taphonomic way” seems here to be more general than trapping.  相似文献   

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