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1.
The new benthic foraminifer Nodocantabricus duplexmurus n. gen., n. sp. is introduced from the lower-lower middle Cenomanian of the Bielba and Altamira formations (North Cantabrian Basin, Spain). This distinctive and atypical Polymorphinidae combines primitive and advanced test characteristics. On the one hand, it fully develops uniserially arranged chambers from an initial spiral coiling, a tendency usually observed in advanced polymorphinids. On the other hand, it possesses a composite, double-layered calcitic wall, made of inner dark microgranular and outer fibro-hyaline layers, a structure seldom documented in post-Paleozoic foraminifers.In the Cretaceous, various polymorphinid groups record significant diversification periods, which taxonomic, phylogenetic and stratigraphic significances have not been evaluated yet. We here discuss the long term evolution of the family Polymorphinidae and its phylogenetic relationship(s) with the family Nodosariidae. A tendency to reversal in the chamber arrangement, from spiral to uniserial, is initiated in the Cenomanian. This evolutive inclination may later have originated a false “nodosariid” lineage, casting doubt upon the assumed monophyly of the family Nodosariidae.  相似文献   

2.
A new larger benthic foraminifera is described as Banatia aninensis n. gen., n. sp. (Family Pfenderinidae Smout & Sugden) from upper Barremian Urgonian-type shallow-water carbonates of the Reşita – Moldova Nouă Zone, southwestern part of Romania. The low to medium trochospiral test of Banatia n. gen. is characterized by marginally undivided chambers and a wide axial part. The latter is made up of pillars continuous between successive chambers and a labyrinthic endoskeleton (plates and pillars) with a fine canal system between. Banatia n. gen. is compared with Pfenderina Henson, Pseudopfenderina Hottinger, and Accordiella Farinacci. The new taxon occurs in algal-foraminiferal wackestones interpreted as deposits of an internal lagoonal realm. So far unrecorded in the literature, the taxon might be paleogeographically restricted (endemic).  相似文献   

3.
The Soritoidea (Foraminifera) represent an important component of Cenomanian microfossil assemblages of the central and southern Tethyan carbonate platforms and are widely used as biostratigraphic markers. In this paper a new taxon, Fissumella motolae n. gen. n. sp., is described from the Cretaceous carbonate platform facies of central and southern Italy. It is characterized by its small size, planispiral-involute arrangement of chambers, fissure-shaped single aperture and few and short radial septula subdividing the marginal lumen of the chambers. Fissumella motolae n. gen. n. sp. represents the first soritoidean in the fossil record showing internal subdivisions of the chamber lumen. Carbon isotope stratigraphy supports an earliest Albian age for this significant step in the evolution of the superfamily Soritoidea. The new subfamily Fissumellinae is established for soritoidean foraminifera with planispiral-involute lens-shaped shells, single aperture and chamber lumen subdivided by few and short septula.  相似文献   

4.
A new large conical agglutinating benthic foraminifer is described as Cantabriconus reocinianus n. gen., n. sp. from the upper Aptian-lower Albian Urgonian limestones of the Basque-Cantabrian Basin. It is characterized by a prominent initial trochospire, an undivided marginal zone, an endoskeleton of massive, vertically aligned, and often fused pillars, as well as a thick, most likely pseudo-keriothecal wall structure. Due to the generic characteristics, the new taxon is assigned to the Coskinolinidae. Cantabriconus n. gen. is compared with the Cretaceous Pseudolituonella Marie, and the early Paleogene taxa Coskinolina Stache and Coskinon Hottinger & Drobne as well as the Middle Jurassic Conicopfenderina Septfontaine. Cantabriconus reocinianus n. gen., n. sp. has been observed in the upper Aptian Reocín Formation and in the lower part of the Albian Ramales and Meruelo Formations to the east of Santander. It might therefore be considered an index taxon for Urgonian-type limestones of the Basque-Cantabrian Basin in this time interval.  相似文献   

5.
The Upper Cretaceous shallow-water carbonates of the Pyrenean Basin (NE Spain) host rich and diverse larger foraminiferal associations which witness the recovery of this group of protozoans after the dramatic extinction of the Cenomanian–Turonian boundary interval. In this paper a new, large discoidal porcelaneous foraminifer, Broeckina gassoensis sp. nov., is described from the middle Coniacian shallow-water deposits of the Collada Gassó Formation, in the Bóixols Thrust Sheet. This is the first complex porcelaneous larger foraminifer of the Late Cretaceous global community maturation cycle recorded in the Pyrenean bioprovince. It differs from the late Santonian–early Campanian B. dufrenoyi for its smaller size in A and B generations and the less developed endoskeleton, which shows short septula. Broeckina gassoensis sp. nov. has been widely employed as a stratigraphic marker in the regional geological literature, under the name of “Broeckina”, but its age was so far controversial. Its middle Coniacian age (lowermost part of the Peroniceras tridorsatum ammonite zone), established in this paper by strontium isotope stratigraphy, indicates that it took about 5 My after the Cenomanian–Turonian boundary crisis to re-evolve the complex test architecture of larger foraminifera, which is functional to their relation with photosymbiotic algae and K-strategy.  相似文献   

6.
The new crustacean microcoprolite Sulcusina iberica n. ichnogen., n. ichnosp., is described from the Upper Cretaceous Alarcón Formation (?uppermost Cenomanian to ?lower Coniacian) of the Southern Iberian range. The new ichnogenus is characterized by rod-shaped bodies with parallel-running longitudinal canals (without interconnecting lines) of rounded transverse sections within the symmetry plane. Characteristic is the presence of a central longitudinal furrow (or canal) that extends to the middle of the microcoprolite, without any connection to the laterally grouped canals of usually lower diameter. The latter display a circular outline in transverse sections. Sulcusina n. ichnogen. can be compared to some extant with both Helicerina Brönnimann & Masse and Lercarina Senowbari-Daryan. The new microcoprolite occurs in monotypic grainstones together with some thin-walled miliolids and ostracods ascribed to a peritidal facies.  相似文献   

7.
In this paper, we present an integrated study of the macrofauna (Cephalopoda), microfauna (Ostracoda and Foraminifera), microflora (Pithonella, Dinoflagellata, Acritarcha and Prasinophyta) and geochemical signals (carbon δ13C and oxygen δ18O stable isotopes) of the upper Cenomanian and lower Turonian succession in Puentedey, Iberian Trough, Spain. This palaeontological and geochemical study has enabled us to identify numerous species of cephalopods (29), ostracods (19), benthic foraminifers (31), planktonic foraminifers (15), dinoflagellates (63), and acritarchs and prasinophytes (11), and to recognise two positive excursions of the δ13C signal related to the OAE2 (in the Metoicoceras geslinianum and the Spathites (Jeanrogericeras) subconciliatus zones, respectively). Variations of these macrofaunal, microfaunal, microfloral and geochemical signals have been interpreted to identify important events of the palaeoenvironmental evolution of the inner platform of the Iberian Trough during the studied interval of the Late Cretaceous. Benthic ecosystems were severely affected by the establishment of the Oceanic Anoxic Event 2 (OAE2) at the end of the late Cenomanian. This event is evidenced by the depletion of calcareous microfauna (benthic calcareous free intervals, BCFI) and the survival of opportunistic microfauna (platycopic ostracods and textulariid foraminifers). The response was different for microflora (dinoflagellates and acritarchs), which were less affected by the anoxic event.  相似文献   

8.
A chart of infrazonal biostratigraphic subdivision of Cenomanian-Coniacian deposits in the East European paleobiogeographic province is based on distribution of benthic foraminifers. The suggested chart characterizes successive trend of changes in ecologic assemblages of benthic foraminifers and morphologic evolution of certain agglutinated (Gaudryina, Bolivinopsis, Heterostomella, Arenobulimina, Ataxophragmium, Ataxoorbignyna, Marssonella) and secretory (Globorotalites, Valvulinera, Gyroidinoides, Stensioeina, Osangularia, Berthelina, Pseudovalvulineria, Gavelinella, Cibicides, Praebulimina, Reussella) foraminiferal genera. The chart includes 7 zones and 13 subzones, most of which are recognizable over the vast territory from the Mangyshalk to southern Baltic areas. It is correlated with the acknowledged ammonoid and inoceramid zonations. Five stadia of taxonomic changes in foraminiferal assemblages, which are substantiated in this work, show that principal biotic events took place in the mid-late Cenomanian, during the Cenomanian-Turonian and early-middle Turonian transitions, in the late Turonian, and at the early-middle Coniacian boundary time.  相似文献   

9.
Changes in morphological diversity and taxonomic composition of late Albian-early Turonian foraminiferal and radiolarian assemblages from the northern Peri-Tethys are considered. Several stages are defined in evolution of planktonic foraminifers: polytaxic (Albian-Cenomanian), oligotaxic (Cenomanian-Turonian boundary period), and polytaxic (Turonian). The Albian-Cenomanian stage was characterized by intense development of rotaliporids representing an intricate group of planktonic foraminifers, which became extinct in the terminal Cenomanian. An intense speciation of the radiolarian genus Crolanium and last occurrences of its most species, the index species C. cuneatum included, was characteristic of the terminal Albian. Spheroid and discoid radiolarians were dominant in the Cenomanian, while the Turonian was marked by intense development of all the radiolarian morphotypes.  相似文献   

10.
The new caprinoidean rudist bivalve Cobbanicaprina bighornensis gen. nov., sp. nov. is described from the upper middle Cenomanian of Big Horn County, Montana, USA. Cobbanicaprina gen. nov. is closely related to Mexicaprina and differs from that form in the absence of an external ligamental groove. The presence of Cobbanicaprina gen. nov. in the middle Cenomanian indicates that the Caprinuloideidae did not become extinct at the top of the Albian and persisted into the Cenomanian. The presence of this specimen so far north in the Western Interior Seaway is attributed to a dried-out individual specimen having been transported post-mortem by currents.  相似文献   

11.
A new genus and species of clupeomorph fish, Leufuichthys minimus, is described from the fluvial deposits of the Portezuelo Formation, Upper Cretaceous (Turonian-Coniacian) of the Neuquén Group, Patagonia, Argentina. It is a small-sized fish with an estimated body length up to 46 mm. Among other characters, the new species shows the following: abdominal scutes; abdomen moderately convex; anal fin elongate-based; three uroneurals; two epurals; caudal fin bearing very elongate rays; and cycloid scales. Leufuichthys minimus gen. et sp. nov. shows a greater similarity with Kwangoclupea dartevellei, a clupeomorph described from a marine Cenomanian deposit of the Democratic Republic of Congo (Africa), mainly due to the presence of an elongate-based anal fin, bearing more than 20 fin-rays, differing from it by the presence of a not hypertrophied abdomen. As far as known, L. minimus gen. et sp. nov. is the first clupeomorph described in the Upper Cretaceous of Patagonia and represents one fortuitous preservation of an articulated fish in fluvial deposits.  相似文献   

12.
We studied upper Albian to Turonian shallow-marine shelf deposits (Ajlun Group) of west central Jordan along a NNE-SSW running transect. The carbonate-dominated succession includes few siliciclastic intercalations, claystones and shales, and can be subdivided into five formations. The Naur, Fuheis and Hummar Formations of upper Albian to upper Cenomanian age represent shallow subtidal to supratidal platform environments. The uppermost Cenomanian to middle Turonian Shueib Formation includes deeper water deposits of the inner/mid-shelf and locally TOC-rich black shales. Shallow-marine platform environments once again dominate the Wadi As Sir Formation (middle-upper Turonian). A new multibiostratigraphic framework is based on ammonites (mainly of the middle Cenomanian rhotomagense Zone to the middle Turonian woollgari Zone) and calcareous nannofossils (biozones CC 9–CC 11), supplemented by benthic and planktonic foraminifers and ostracods. It forms the base of a sequence stratigraphic subdivision, containing eight sedimentary sequences (S1–S8), which are separated by four Cenomanian sequence boundaries (CeJo1–CeJo4) and three Turonian sequence boundaries (TuJo1–TuJo3). This scheme allows the correlation of the platform succession from distal to proximal shelf areas in contrast to previous correlations using lithologic units. Furthermore, comparisons between the platform successions and sequence patterns of west central Jordan and those from neighbouring areas allow to differentiate local, regional, and global controlling factors of platform development within the study area.  相似文献   

13.
A new genus and species of the ant-like stone beetle supertribe Mastigitae, Cretoleptochromus archaicus gen. et sp. nov., is described and figured based on an exceptionally well-preserved individual in the Upper Cretaceous (lowermost Cenomanian, ca. 99 Ma) amber from Myanmar. Cretoleptochromus is undoubtedly placed in Mastigitae based on its distinctly geniculate antennae with strongly elongate antennal scape, and pointed labial palpomere III. Cretoleptochromus is most likely the sister taxon to the extinct Palaeoleptochromus O'Keefe from the Late Cretaceous Canadian amber. Cretoleptochromus shares with Clidicini the distinct posterior collar of pronotum; with Leptomastacini the presence of mesocoxal lateroventral bristles. The new discovery may help to elucidate the relationships among the Recent three tribes, particularly for Leptomastacini and Clidicini.  相似文献   

14.
A remarkable new genus and species, Mesallotrochus longiantennatus n. gen. n. sp., is described and figured based on a well-preserved individual in the lowermost Upper Cretaceous (Cenomanian) amber from Myanmar. Mesallotrochus is placed in the extant tribe Thoracophorini based on its general habitus, including the protibia with inner edge straight, without ctenidium, exposed protrochantins, open procoxal cavities, and more or less flatted body. Mesallotrochus is separated from other allied genera by the long antennae, very long maxillary palpomere 4, contiguous procoxae, and well-developed anterolateral pronotal angles. The new discovery of the oldest Osoriinae from about 99 million years not only suggests the antiquity of the subfamily, but also bears significant biogeographic implications.  相似文献   

15.
Suraqalatia brasieri n.gen., n.sp. from the family Dicyclinidae Loeblich and Tappan 1964 occurs on the Maastrichtian carbonate platform of northern Iraq. The new genus is recognizable by its large very compressed conical test, up to 55–70 mm in diameter, to 0.3–1.6 mm in thickness, planspiral cooling having very small proloculus in the initial part and later circular chambers including numerous chamberlets with an agglutinated wall. Suraqalatia brasieri n.gen., n.sp. is associated with textulariids, miliolids and rotaliids as Loftusia elongata Cox, L. morgani Douvillé, Orbitoides medius d’Archiac, O. megaloformis Papp & Kupper, O. gruenbachensis Papp, O. apiculatus Schlumberger, Omphalocyclus macroporus (Lamarck), Siderolites calcitrapoides Lamarck, Sirtina orbitoidiformis Brönnimann & Wirz. The associated macrofauna comprises large and rich giant rudists (Preradiolites sp.), other bivalves (Gryphaea sp. and Glycymeris sp.), gastropods (Acteonella sp.), echinoderms and corals. The fauna indicates shallow marine carbonate platform conditions within the Maastrichtian green house. It is also worth mentioning that the new genus has only been recorded from the Maastrichtian age.  相似文献   

16.
The Cenomanian–Turonian boundary was characterized by distinctive positive carbon isotope excursions that were related to the formation of widespread oceanic anoxia. High-resolution geochemical proxies (TOC, CaCO3, δ13Corg, and δ13Ccarb) obtained from bulk rock, planktic foraminifers, and inoceramids from four marine marlstone-dominated stratigraphic sections in the Western Canada Sedimentary Basin (WCSB) were used to establish a regional carbon isotope stratigraphic framework and to investigate paleoenvironmental variability in four different depositional settings. Compared to background δ13Corg, (<−27‰) and δ13Ccarb (<2‰) values which were correlative to stable isotope excursions during Oceanic Anoxic Event (OAE) II worldwide, the δ13Corg (>24‰), and δ13Ccarb (>4‰) derived from inoceramid prisms in the studied sections within WCSB, were elevated during the Late Cenomanian–Early Turonian. During this interval, TOC and CaCO3 values which increased sporadically to >40% and 7%, respectively, were not consistent enough to be used for stratigraphic correlations. Based on the δ13Corg excursions, two bentonite beds were regionally correlated across this portion of the Western Interior Seaway (WIS). The eruption associated with the “Red” bentonite occurred approximately coeval with the maximum δ13Corg-excursion during OAE II in the Neocardioceras juddii Zone, whereas the “Blue” bentonite coincides with the termination of OAE II in the latest Watinoceras devonense zone. During the Late Cenomanian–Early Turonian in the WCSB, benthic foraminifers were sparse or totally absent, indicating the existence of fully anoxic bottom-water conditions. Planktic foraminifera were common in the well-oxygenated surface waters. A benthic oxic zone characterized by several agglutinated species occurs in the eastern part of the WSCB at the beginning of OAE II in the Sciponoceras gracile zone. The termination of the OAE II in the WCSB coincides with the first occurrence of small ammonites (Subprionocyclus sp.) in the western part of the basin.  相似文献   

17.
The first alveolinoidean appearing in the Cenomanian Natih Formation of Oman (Adam foothills and southern edge of Jabal Akhdar) are studied in detail. Morphological analysis results in the creation of one new family, Myriastylidae, two new genera, Myriastyla and Alveocella, and four new species, M. omanensis, M. grelaudae, A. wernliana, and Cisalveolina nakharensis. These four new taxa have a short stratigraphic extension restricted to the uppermost part of Natih E unit and are dated early middle Cenomanian by neighboring foraminifers and ammonite levels.  相似文献   

18.
A new genus and species of tetrablemmid spider, Electroblemma bifida n. gen. et sp., is described, from two adult males found in Upper Cretaceous (Cenomanian) amber of Myanmar. The genus is distinguished by its enormous dorsal carapace projection and highly modified chelicerae. The new genus is referred to the tribe Tetrablemmini within the subfamily Tetrablemminae. The presence of a relatively derived tetrablemmid on the south-east Eurasian continent during the Late Cretaceous suggests that the family was already well diversified in tropical rainforests at this time.  相似文献   

19.
Distribution of belemnites and benthic foraminifers in the Campanian-Maastrichtian boundary layers of the Aktulagai section, one of Upper Cretaceous reference sections in the east of the European paleobiogeographic region (EPR) is discussed. The base of Lanceolata Beds defined by A.D. Arkhangelsky in 1912 is well-substantiated biostratigraphic level corresponding to boundary between the Campanian and Maastrichtian stages. In spacious outcrops of Upper Cretaceous deposits in the Aktulagai Plateau (Aktyubinsk region, Kazakhstan Republic), “primitive Belemnella forms” (two rostra plates) appearing above that base distinctly replace the genus Belemnitella dominant in the Campanian. Seven successive zonal assemblages of benthic foraminifers (one plate) are established in the boundary interval. The Aktulagai reference section of Upper Cretaceous sediments can be used to trace the Campanian-Maastrichtian boundary from the eastern EPR to Boreal regions of Russia based on abundant micro-and nannofossils.  相似文献   

20.
In the northern Aurès Range near Batna, Algeria, the Cenomanian Smail Marls Formation consists of fossiliferous deposits rich in diverse benthic macrofauna, mostly dominated by bivalves, among them the carditid Maghrebella forgemoli (Coquand, 1862). Almost exclusively Cenomanian, the abundance zone of Maghrebella forgemoli is in the higher levels of Lower Cenomanian, extending from the Sharpeiceras schlueteri zone to the Mantelliceras dixoni zone and corresponds to a limited circalittoral interval with relatively low energy, soft substrata, and relatively cold temperatures. The distribution of Maghrebella forgemoli in Mountains of Batna evidences bathymetric variation controlled by the tectonic activity affecting the ante-Triassic and the Upper Cretaceous substrata and generating a system of tilted blocks, at the beginning of the uppermost Albian-Cenomanian and Turonian, in the eastern Atlasic domain that extends to central Tunisia.  相似文献   

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