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1.
The Lower and Upper Cretaceous deposits from the Brazilian marginal basins present a rich and diversified fauna of ostracodes in continental, marine and mixohaline paleoenvironments. While the Cretaceous ostracodes from the northeastern region have already been the subject of many taxonomic and biostratigraphical studies, data from the southeastern basins are still scarce and restricted to the record of a few species. The present study represents a comprehensive contribution to the systematic knowledge of the Aptian–Santonian ostracodes from the Brazilian southeastern marginal basins. A total of 1045 cutting samples were analyzed from 10 wells drilled offshore in Santos, Campos and Espírito Santo basins. Thirty-eight ostracode taxa were recorded from different depositional environments, including the following six new species: Amphicytherura fragilis sp. nov., Brachycythere multidifferentis sp. nov., Fossocytheridea ballentae sp. nov., Fossocytheridea elegans sp. nov., Nigeroloxoconcha itanhaensis sp. nov. and Paracypris eniotmetos sp. nov.  相似文献   

2.
Heterogenous megaspores recovered from the Upper Permian sediments of Kuraloi Area, Ib-River coalfield, have been systematically described. The megaspore assemblage includes seven genera with seventeen species viz. Bokarosporites rotundus, Banksisporites indicus, B. utkalensis, Biharisporites spinosus, Biharisporites sp.A, Biharisporites sp.B, Jhariatriletes baculosus, J. srivastavae, J. damudicus, Manumisporites distinctus, Singhisporites baculatus, S. radialis, S. surangei, Ramispinatispora indica, R. nautiyalii and Ramispinatispora sp. Additionally, a new species of Ramispinatispora viz. R.mahanadiensis has been identified. Associated spore pollen assemblages are suggestive of a Late Permian age corresponding to Raniganj/Kamthi Formation. Raniganj megaspores are known from Damodar and Godavari Basins. The newly recorded megaspore assemblage from the Ib-River coalfield is comparable to that of Raniganj/Kamthi Formation of Godavari Graben. The diversity in exosporium ornamentations indicates structural diversity. Moreover, their prolific presence ultimately points towards occurrence of heterosporous source vegetation in the area.  相似文献   

3.
Among the smaller foraminifers from the Lower Permian of Western Tethys (Pamir, Northern Afghanistan, Central and Eastern Iran, Armenia, and Turkey), foraminiferal assemblages characteristic of the Asselian, Sakmarian, Yakhtashian, Bolorian, and Kubergandian stages are distinguished. The first stratigraphic scheme based on smaller foraminifers is elaborated for the Lower Permian (Cisuralian Series) of Western Tethys. Eight biostratigraphic units distinguished in the Lower Permian and one in the Kubergandian Stage are ranked as beds with characteristic foraminiferal assemblages. At particular stratigraphic levels, the beds are recognizable in different paleogeographic provinces of the Tethyan Realm, which enables correlation between deposits concurrently accumulated under dissimilar climatic and facies conditions to be carried. Some of the distinguished beds are recognizable beyond the Tethyan Realm, for instance in the Donetsk basin, Cis-Urals, Pechora coal basin, and Spitsbergen. Among foraminifers that have been studied, 264 species and subspecies, including 16 new taxa, are identified. The following species and subspecies are identified and described for the first time: Hemigordius permicus beitepicus subsp. nov., H. pamiricus sp. nov., Neohemigordius afganicus sp. nov., N. carnicus sp. nov., N. bangi sp. nov., N. zulumarticus sp. nov., N. kubergandinicus sp. nov., Geinitzina grandella sp. nov., G. dentiformis sp. nov., G. bella sp. nov., Pachyphloia paraovata minima sp. nov., P. aucta sp. nov., Frondicularia porrecta sp. nov., Globivalvulina gigantea sp. nov., G. compacta sp. nov., and G. explicata sp. nov.  相似文献   

4.
The Albian Alexander Island macrofossil flora from the Antarctic Peninsula preserves a diverse community of liverworts (Marchantiophyta), ferns (Polypodiopsida), Lycopodiales, Equisetales, Cycadales, Ginkgoales, seed-ferns (Bennettitales and Pentoxylales), Coniferales, and the first representatives of angiospermous leaves in Antarctica. Despite the presence of angiosperms in this assemblage, ferns are the most diverse element of the flora and are also ecologically dominant, while angiosperms contribute a smaller component to floristic diversity and have low abundance. Here we describe 11 fern taxa from this assemblage. The fossils are assigned to Cladophlebis, Sphenopteris and two newly created genera. The new genera and species are described under Adiantitophyllum serratum gen. et. sp. nov. and Nunatakia alexanderensis gen. et. sp. nov., and the new species are recognized as Cladophlebis dissecta sp. nov., Cladophlebis drinnanii sp. nov., Cladophlebis macloughlinii sp. nov. and Sphenopteris sinuosa sp. nov. In total, there are 24 fern species known from Alexander Island. In comparison to older floras (Jurassic) there is a greater diversity of ferns, while latest Cretaceous floras preserve significantly fewer fern species and more angiosperms. Possible factors that might account for such high fern diversity are high rainfall or generally humid conditions, regular disturbances by flooding and occasionally fire, and the preservation of a diverse range of fern communities that represent several palaeoenvironments.  相似文献   

5.
《Gondwana Research》2014,25(1):420-437
A new assemblage of early Cambrian bivalved arthropods (Bradoriida) is described from the Arrowie Syncline in the northern Flinders Ranges, South Australia. The well preserved, largely endemic fauna comprises a total of six taxa (including five new species): Jiucunella phaseloa sp. nov., Jixinlingella daimonikoa sp. nov., Mongolitubulus anthelios sp. nov., Neokunmingella moroensis sp. nov., Phasoia cf. spicata (Öpik, 1968), and Sinskolutella cuspidata sp. nov. This assemblage is derived from a carbonate sedimentary package representing a high energy, shallow water archaeocyath-Renalcis biohermal facies of Terreneuvian, Stage 2 age which transitions up-section to a more restricted, low energy, intra-shelf lagoonal environment that correlates with a Cambrian Series 2, Stage 3 age. The new taxon J. phaseloa sp. nov., has a first appearance datum (FAD) in shallow water biohermal facies of the Hideaway Well Member of the Wilkawillina Limestone at a level 47 m below the FAD of Pelagiella subangulata which is taken to approximate the base of Series 2, Stage 3 in South Australia. Along with Liangshanella circumbolina, this makes J. phaseloa sp. nov. amongst the oldest bivalved arthropods in South Australia and potentially greater Gondwana. The presence of 25 bradoriid taxa from the early Cambrian of South Australia suggests East Gondwana represents a major centre of origin for the Bradoriida.  相似文献   

6.
A rich assemblage of palynomorphs including miospores and megaspores has been recorded from the bore core no. IBKAN-2 drilled at a depth of 17.80m in Kuraloi Block-A, south-west part of the Ib-River Coalfield, Jharsuguda district, Odisha. The miofloral assemblage recovered shows prominence of cingulate, zonate, taeniate, non-striate and non saccate palynotaxa which indicate an early Triassic age and is comparable with the palynoassemblages of the same age known from the Damodar basin, India. The megaspore assemblage includes eight genera and fifteen species namely, Banksisporites karanpuraensis, B. indicus, B. utkalensis, Banksisporites sp., Barakarella pantii, Barakarella sp., Biharisporites spinosus, Biharisporites sp., Erlansonisporites triassicus, Erlansonisporites cf. erlansonii, Erlansonisporites sp. Jhariatriletes sp., Singhisporites sp., Ramispinatispora sp. and Talchirella trivedii. Records of megaspores are sparse in the early Triassic of Gondwana basins of India. The present study records the first occurrence of miospores and megaspores from the early Triassic of Mahanadi basin besides substantiating the earlier data.  相似文献   

7.
Three new species within the stigmaphronid genus TagsmiphronEngel and Grimaldi, 2009, and one new species within the megaspilid genus ConostigmusDahlbom, 1858 are described from Upper Cretaceous (Campanian) amber originating at the Grassy Lake locality in Alberta, Canada. New taxa include Tagsmiphron spiculum sp. nov., Tagsmiphron leucki sp. nov., Tagsmiphron exitorum sp. nov., and Conostigmus cavannus sp. nov. The new Conostigmus species is a rare discovery. It is the third megaspilid species to be found in Cretaceous amber, with the two specimens described herein effectively doubling the number of known Mesozoic exemplars for the family. We provide the first comprehensive report of known Ceraphronoidea within Canadian amber, and contrast this against other Cretaceous amber assemblages, discussing the potential palaeobiogeographic and palaeoenvironmental implications of the Canadian amber assemblage.  相似文献   

8.
Based on the palynological data from Well Ta-19-36 and Well Ta-19-37 in the Ta'nan Sag, and Well Ta-22-1 and Well Ta-21-1 in the Bayin Gobi Sag, a spore-pollen assemblage from the Damoguaihe Formation is named as Cicatricosisporites minutaestriatus- Aequitriradites spinulosus-Protopinus sp. assemblage in the Tamutsag Basin, Mongolia. The assemblage is characterized by abundant gymnosperm pollen and diverse fern spores, counted 46.35%–65.57% and 34.43%–52.58% in percentage respectively. Among the gymnosperm pollen, Pinuspollenites sp.(2.66%–16.94%), Protopinus sp.(0–11.38%) and Protopicea sp.(0–10.81%) are dominant; and Alisporites sp., Cerebropollenites sp., Podocarpidites sp., and Abietineaepollenites sp. are common. Some important elements, such as Chasmatosporites sp., Callialasporites prominulus, Parvisaccites sp., Parcisporites sp., Jiaohepollis cf. annulatus, J. bellus, J. verus, Polycingulatisporites sp., Schizaeoisporites certus, Classopollis annulatus are seen. Within the fern spores, Osmundacidites wellamanii(0.85%–4.93%), Appendicisporites sp.(0–4.45%), Baculatisporites comaumensis(0.80%–2.87%), Cicatricosisporites sp.(0.51%–2.66%), C. minor(0–2.14%), Foraminisporis asymmetricus(0–2.40%), Aequitriradites sp.(0– 2.19%) and Cyathidites minor(0–2.13%) are dominant; and some specie of Densoisporites, Cooksonites, Impardecispora, Pilosisporites, Schizaeosprites, Fixisporites, Leptolepidites, Trilobosporites, Kuylisporites, Klukisporites, Hsuisporites, Couperisporites, Maculatisporites are seen. The angiosperm pollen are rare in the assemblage, characterized by Clavatipollenites sp.(0–0.80%) and Songipollis sp.(0–0.27%). The geological age of the Damoguaihe Formation is assigned to Hauterivian – Barremian of Early Cretaceous according to the palynological data, due to the fact that there existed a lot of diverse spores of the family Schizaeaceae and prosperous gymnosperm saccat pollen which the corpus and sacci are differentiated completely, and the presence of early angiosperm pollen of Clavatipollenites. However, the zircon U-Pb isotopic dating of the volcanic rocks in the Nantun Formation indicated that the overlying strata of the Nantun Formation, i.e. the Damoguaihe Formation must be younger than 127.0±2.0–137.9±1.5 Ma. This is consistent with the palynological data. Furthermore, the vegetation reconstructed on the palynological data of the Damoguaihe Formation is conifer forest with shrubs and grassland, belonging to the semi-humid or humid middle to south subtropical climate. Moreover, three new species, namely Biretisporites punctatus sp. nov., Chasmatosporites reticulates sp. nov. and Concentrisporites contractus sp. nov. are described here.  相似文献   

9.
丁秋红  傅晓平  李勇  张武 《世界地质》2010,29(4):527-542
本文报道了产自蒙古东南部晚侏罗世至早白垩世的木材化石7属8种。其中,包括3个新种(Protaxodioxylon mongolense sp.nov.,Circoporoxylon mongolense sp.nov.,Protocircoporoxylon mongolense sp.nov.)和5个已知种(Protocupressinoxylon coromandelinum,Protocupressinoxylon mishanense,Xenoxylon latiporosum,Protophyllocladoxylon franconicum,Protocedroxylon lindicianum)。作者对这些木化石解剖特征做了详细描述,并对其古气候环境进行了分析与探讨。  相似文献   

10.
11.
A diverse fauna of wasps of the extinct parasitoid family Stigmaphronidae (Ceraphronoidea) are recorded in Early Cretaceous (Lower Albian) amber from Spain. Seven new species in five genera are described and figured based on 51 specimens, representing more material than in all the world’s other amber deposits combined. New species include: Elasmophron mari sp. nov., Libanophron sugaar sp. nov., Hippocoon basajauni sp. nov., Burmaphron jentilak sp. nov., B. sorginak sp. nov., B. iratxoak sp. nov., and Tagsmiphron olentzero sp. nov. The significance of the fauna is discussed and compared with that of other Cretaceous amber deposits, in particular the tremendous richness of the Spanish fauna is contrasted with the complete absence of stigmaphronids in the slightly younger and nearby French amber. Whether this stark difference represents particularly favorable conditions for these parasitoids, or their hosts, in the Cretaceous Spanish archipelago, or whether it is owing to taphonomic factors is discussed.  相似文献   

12.
New Mesozoic Mesopsychidae(Mecoptera)from Northeastern China   总被引:2,自引:2,他引:0  
<正>The Mesozoic family Mesopsychidae Tillyard,1917 presently consists of seven described genera and 13 species from the mid-Triassic to the Early Cretaceous of Australia,South Africa and Eurasia.In the present paper one new genus and three new species of fossil mesopsychids are described that add significant distributional and stratigraphic extensions to the family.This finding documents the first formal record of fossil Mesopsychidae in China.Both Lichnomesopsyche gloriae gen.et sp.nov.and L.daohugouensis gen.et sp.nov. were found from the Middle Jurassic Jiulongshan Formation of Inner Mongolia,whereas Vitimopsyche kozlovi sp. nov.,of mid Early Cretaceous age,was collected from the Jehol Biota of northern Hebei Province.This new,well-preserved material from China reveals complete and previously unknown body features,including head, antennae,mouthparts,legs and abdomen.The delicate and long proboscides of these new taxa indicate that they were feeding on externally exposed,nutrient-rich fluids of gymnospermous ovulate fructifications,and incapable of piercing surface epidermis-attributable principally to the absence of stylets.These proboscides originated, perhaps multiply,among basal Mecoptera and are functionally and structurally convergent with equivalent mouthparts borne by fossil and extant Diptera,Lepidoptera,Neuroptera and Coleoptera.  相似文献   

13.
Early Cretaceous elasmobranchs still are very insufficiently known despite all progress that has been accomplished in recent years. Here, a small elasmobranch assemblage is presented from the Valanginian of Austria that contributes significantly to a better understanding of early Cretaceous elasmobranch diversity. The new assemblage comprises two new carcharhiniform sharks, Altusmirus triquetrus gen. et sp. nov. and Fornicatus austriacus gen. et sp. nov., a new orectolobiform shark, Similiteroscyllium iniquus gen. et sp. nov., and a galeomorph shark tooth of uncertain affinities. The recent identification of Similiteroscyllium gen. nov. has shown that it has strong similarities with Ornatoscyllium rugasimulatum from the Lower Cretaceous of France. Significant differences of the tooth morphology of O. rugasimulatum and the type specimen O. freemani justify full reconsideration of the systematic position of O. rugasimulatum and require it to be reassigned to Similiteroscyllium gen. nov. described in this paper. The new assemblage described here, and those from the Valanginian of France and Poland comprising 30 additional taxa, indicates that Early Cretaceous elasmobranch diversity was significantly higher than previously assumed. Consequently, the supposed diversity decline of elasmobranchs across the Jurassic-Cretaceous boundary represents a collecting bias rather than a real pattern.  相似文献   

14.
《Cretaceous Research》2012,33(6):794-805
Three new species within the stigmaphronid genus Tagsmiphron Engel and Grimaldi, 2009, and one new species within the megaspilid genus Conostigmus Dahlbom, 1858 are described from Upper Cretaceous (Campanian) amber originating at the Grassy Lake locality in Alberta, Canada. New taxa include Tagsmiphron spiculum sp. nov., Tagsmiphron leucki sp. nov., Tagsmiphron exitorum sp. nov., and Conostigmus cavannus sp. nov. The new Conostigmus species is a rare discovery. It is the third megaspilid species to be found in Cretaceous amber, with the two specimens described herein effectively doubling the number of known Mesozoic exemplars for the family. We provide the first comprehensive report of known Ceraphronoidea within Canadian amber, and contrast this against other Cretaceous amber assemblages, discussing the potential palaeobiogeographic and palaeoenvironmental implications of the Canadian amber assemblage.  相似文献   

15.
A new genus with two new species, Orentalphila gravia gen. et sp. nov. and O. caloa sp. nov., and three new species in two known genera, Sinosciophila angustia sp. nov., Sinosciophila seboa sp. nov. and Similsciophila undulata sp. nov., are described from the Lower Cretaceous of Yixian Formation at Huangbanjigou, Beipiao City, western Liaoning, China. These new taxa, representing the first records of mesosciophilids from this locality, provide morphological information and diversity for Mesosciophilidae in the Early Cretaceous. An updated key to known genera of Mesosciophilidae is provided. In addition, according the generic diagnosis revised by Zhang, 2007, Mesoplecia antiqua Hao and Ren, 2009 should be transferred to Mesosciophila Rohdendorf, 1946.  相似文献   

16.
The history of investigation of the common Jurassic and Cretaceous genus Pseudotorellia Florin (Ginkgoales) represented by needle-shaped, narrow linear or lanceolate leaves bearing several veins and characterized by a single type of epidermis, is considered. An extended diagnosis of the genus and its taxonomic composition with regard to the epidermal characters are reported; the stratigraphic and geographical range of its species and the genus evolution are refined. Three new species Pseudotorellia asiatica N. Nosova et Kiritchkova, sp. nov., P. ketoviana N. Nosova et Kiritchkova, sp. nov., and P. samylinae N. Nosova et Kiritchkova, sp. nov. described from the Lower Jurassic (Toarcian) sediments, are proposed as the correlative taxa within the Caspian oil and gas province. The stratotype and reference sections of the Lower Jurassic sediments in the Mangyshlak Mountains are reported for the first time.  相似文献   

17.
18.
The freshwater ferns (Salviniales) are well represented in the Maastrichtian deposits of Cerro de los Fragmentos in the headwaters of the Río Chico, Golfo San Jorge Basin. The fossil material of Salviniaceae includes complete megaspore apparatuses with attached microspore massulae and dispersed megaspores, float systems and microspore massulae of Azolla. The new species Azolla colhuehuapensis displays distinctive morphological characters including relative small megaspore apparatuses with easily detached floats and usually attached eglochidiate massulae. The Marsileaceae are represented by the megaspore Molaspora lobata, microspores of Crybelosporites and vegetative remains of Marsileaceaephyllum sp. The assemblage also includes zygospores of the green filamentous algae Zygnemataceae, spores of Marchantiophyta and Monilophyta (Schizaeales), megaspores of Isoetalean affinity and Palm-type angiosperm pollen grains. All these organic microfossils and the associated palynomorphs indicate the presence of a freshwater environment where abundant water ferns were developing and reproducing.  相似文献   

19.
This paper discusses a well-represented fossil record of cartilaginous fishes (Chondrichthyes) from southern South America. The recovered samples allow the recognition of three assemblages with chronostratigraphic and paleogeographic value: i) typical Maastrichtian sharks and rays with affinities to eastern Pacific fauna, including the taxa Ischyrhiza chilensis, Serratolamna serrata, Centrophoroides sp. associated to Carcharias sp., and Dasyatidae indet.; ii) a scarce reworked assemblage of Paleocene–Early Eocene age including the taxa Otodus obliquus and Megascyliorhinus cooperi; iii) a rich assemblage with reworked taxa of Early to Middle Eocene age, together with autochthonous deposited Middle to Late Eocene taxa with close affinities to paleoichthyofaunas recovered from the North Atlantic, represented by Carchariashopei’, Odontaspis winkleri, Carcharoides catticus, Macrorhizodus praecursor, Carcharocles auriculatus, Striatolamia sp., Striatolamia macrota, Hexanchus agassizi, Notorhynchus sp., Myliobatis sp., Abdounia sp., Pristiophorus sp., Squatina sp., cf. Rhizoprionodon sp., Ischyodus sp., and one new species, Jaekelotodus bagualensis sp. nov. The studied samples include for the first time taxa with well established chronostratigraphic resolutions as well as taphonomic information that help clarifying the age of the fossil-bearing units. In addition, they provide relevant information about the evolution of the Magallanes (=Austral) Basin from the Upper Cretaceous to the Paleogene, suggesting a probable connection with the Quiriquina Basin of south-central Chile during the latest Cretaceous. Finally, the studied assemblages indicate a latitudinal pattern of distribution that provides valuable data on the environmental evolution and temperature of southern South America during the Paleogene.  相似文献   

20.
A new genus with a new species, Brachypelecinus euthyntus gen. et sp. nov., and two new species, Abropelecinus tytthus sp. nov. and Zoropelecinus periosus sp. nov., are described and figured from three exquisitely preserved pelecinid wasps in the Upper Cretaceous Myanmar (Burma) amber. These taxa, owing to their well-preserved characters in amber, provide a better understanding of morphological changes and relationships among the constituent groups, while further highlighting the diversity of Pelecinidae in the Mesozoic.  相似文献   

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