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1.
《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   

2.
贵州金沙下寒武统牛蹄塘组中的高肌虫   总被引:1,自引:0,他引:1  
描述了贵州金沙岩孔镇长岩沟下寒武统(纽芬兰统一寒武系2统)牛蹄塘组底部黑色页岩中呈碳质薄膜保存的高肌虫化石,共2属1种1相似种和1未定种:朵氏昆明虫Kunmingella douvillei,昆明虫(未定种)Kunmingella sp.和新月形遵义虫相似种Tsunyiella of luna.这些高肌虫化石与最古老的三叶虫Tsunyidiscus(Mianxiiandiscus)共生,其层位可与云南的Abadiella带对比,表明Kunmingella和Tsunyiella的下限层位已下延至筇竹寺阶的底部.本应属于早寒武世高肌虫分布中区的金沙一带却发现了两区的典型分子Kunmingella和中区的Tsunyiella,说明两区与中区间的混生区的范嗣应从长宁-镇雄小区扩大至贵州的金沙和织金一带.贵州寒武系底部大量高肌虫的发现丰富了牛蹄塘生物群的组成,对研究寒武纪早期生物的演化具有一定的意义.  相似文献   

3.
A new chelid species (Prochelidella cerrobarcinae nov. sp.) are described from the Aptian-Albian? Puesto La Paloma Member, Cerro Barcino Formation, northern of Chubut Province, Argentina. The basal section of this member, which bears the turtle remains, is composed of tuffaceous mudstones with plane parallel lamination, asymmetrical ripples and a chert intercalation suggesting sub-aqueous deposition in a relatively shallow lacustrine environment. Pr. cerrobarcinae nov. sp. is represented by post-cranial remains of several specimens that not only represents the oldest pleurodiran chelid record in the world but, together with the chelid remains of Albian Lightning Ridge, New South Wales, Australia, indicates that chelid diversification began well before the final fragmentation of southern Gondwana.  相似文献   

4.
Outcropped of the Kuhbanan Formation at Dahu, near Zarand, about 63 km north of Kerman, Iran contains peri-Gondwana trilobites. In this study, 185 trilobite samples including six species and genera were identified and described from Dahu section. This trilobite’s assemblage including Redlichia noetlingi, Redlichia sp., Kermanella kuhbananensis, Kermanella lata lata, Kermanella lata minuta, Iranoleesia pisiformis, and Iranaspis sp. based on occurrence of the trilobite fauna a late Early to Middle Cambrian (Series 2–3) is suggested for this strata. These trilobite fauna help confirm conclusions from recent geological studies that place the Kerman Basin of Iran during the Cambrian.  相似文献   

5.
In present study the newly recorded latest Middle Cambrian trilobite fauna from the Cambrian succession of the Zanskar region of Zanskar-Spiti-Kinnaur Basin (Tethyan Himalaya) is analyzed critically to assess relationships with other Cambrian faunal elements of equatorial peri-Gondwanaland. The identification of genus Neoanomocarella, Parablackwelderia, Kunmingaspis, Fuchouia, Damesella and Dorypyge from the Cambrian of the Zanskar region and their comparison with those of South China and Australia is significant. It constitutes the basis for assessing the paleobiogeographic affinities during the Cambrian. The latest Middle Cambrian trilobite fauna from Zanskar shows proximity of Indian margin with that of southwest China “outboard” micro-continent. The recovery of analogous Middle Cambrian species i.e., Dorypyge perconvexlis, Fuchouia bulba, Fuchouia cf. oratolimba, Parablackwelderia sp. and Damesella sp. from the Zanskar region (Tethyan Himalaya) suggests a contiguous close proximity with south China and Australia during the latest Middle Cambrian, which supports the model of Meert and Van der Voo (1997) for assembly of Gondwanaland. The presence of Kunmingaspis in Zanskar and similar reports from northwestern Yunnan-Tibetan region, northern Henan, central and southeastern Hubei, north China, western Xinjiang and Yangtze platform reveal a close affinity between the Indian margin and the Yangtze platform during the Middle Cambrian. The trilobite fauna indicates the deeper shelf-shallow slope environment of deposition under fluctuating conditions of relative sea-level. The faunal elements of the Lejopyge acantha and Proagnostus bulbus zones indicate that the sea inundated the northern margin of Zanskar region during the latest Middle Cambrian time (Teta transgression) which is synchronous with globally recognized eustatic events during Lejopyge laevigata Zone.  相似文献   

6.
The angiosperm pollen record from the Anfiteatro de Ticó and Punta del Barco formations (Baqueró Group) is reported. The relevance of these floras is that they are accurately dated as late Aptian, and one of the oldest floras southern South America with fossil angiosperms. Twelve samples were studied, showing Clavatipollenites and Retimonocolpites as dominant types. A new species, Jushingipollis ticoensis sp. nov., is proposed. A doubtful angiosperm pollen grain, Lethomasites sp., is also identified and described. A multivariate analysis of similarities between different Early Cretaceous angiosperm pollen assemblages suggests that the Baqueró Group assemblages have great similarities with other coeval units from Argentina, Australia and United States, which were located in a similar paleolatitude.  相似文献   

7.
Early Cambrian univalve molluscs are predominantly represented by microscopic forms (body length of 1–3 mm), preserved mainly as phosphatised internal moulds with limited definable features. Macromolluscs (≥ 5 mm) are generally rare, occur in low abundance and are poorly preserved, often lacking apical features and ornament which hinders taxonomic assessment. New and previously undescribed material from lower Cambrian Hawker Group carbonates of the Flinders Ranges in South Australia includes four new taxa, Minastirithella silivreni gen. et sp. nov., Galeacalvus coronarius gen. et sp. nov., Helcionella histosia sp. nov., and Ilsanella enallaxa sp. nov. Three-dimensional silicified shell material preserved with intact apices offers new insight into protoconch morphology, growth habit (isometric vs. allometric) and developmental mode. This material supports previous suggestions that some micromollusc taxa may in fact be early ontogenetic stages (juveniles) of larger macroscopic taxa; such that the millimetric size range of helcionelloids conforms to the dimensions of earliest apical portion in some macromolluscs documented herein. However, taphonomic limitations associated with phosphatisation show that the morphology (especially height vs. width) of the apex can greatly influence the probability of steinkern formation and preservation potential for both micro- and macro-scale helcionelloids. Artificial inflation in the appearance of millimetric helcionelloids with an optimal morphology for phosphatisation is thus directly linked to taphonomic biases in the fossil record.  相似文献   

8.
Definition of early Cambrian chronostratigraphic boundaries is problematic with many subdivisions still awaiting ratification. Integrated multi-proxy data from well-resolved regional-scale schemes are ultimately the key to resolving broader issues of global correlation within the Cambrian. In Australia, early Cambrian biostratigraphy has been based predominantly on trilobites. Phosphatic shelly fauna have great potential as biostratigraphic tools, especially in pre-trilobitic strata because they are widespread and readily preserved, but they have remained underutilised. Here we demonstrate their value in a new biostratigraphic scheme for the early Cambrian of South Australia using a diverse shelly fauna including tommotiids, brachiopods, molluscs and bradoriids.Biostratigraphic data are derived from ten measured stratigraphic sections across the Arrowie Basin, targeting Hawker Group carbonates including the Wilkawillina, Wirrapowie and Ajax limestones and the Mernmerna Formation. The stratigraphic ranges of shelly fossils are predictable and repeatable across the Arrowie Basin, allowing three discrete shelly biozones to be identified, spanning Terreneuvian, Stage 2 to Series 2, Stages 3–4. The Kulparina rostrata Zone (new) and part of the overlying Micrina etheridgei Zone (new) are pre-trilobitic (predominantly Terreneuvian). The Cambrian Series 2, Stage 3 Dailyatia odyssei Zone (new) features a very diverse shelly fauna and will be described in detail in a separate publication. These zones provide robust means to correlate Terreneuvian–Series 2 successions in neighbouring coeval basins in Australia, particularly the Stansbury Basin. Wider correlation is possible throughout East Gondwana, and especially with South China.  相似文献   

9.
Diverse thoracican cirripedes from the Hauterivian of the Hannover district of northern Germany are described, including seven species, belonging to five genera. Of these, a new genus belonging to the Scalpellidae, Jaegerscalpellum, includes one Hauterivian species, J. elegans sp. nov., an Aptian species, J. comptum (Withers, 1910) and an Albian species, J. politum (Darwin, 1851) are also referred to it. A new Cretiscalpellum, C. mutterlosei sp. nov. is described from the Hauterivian, and C. matrioni sp. nov. is described from the Middle Albian of France. The oldest record of the Unilatera Gale, 2018, Pedupycnolepas pulcher sp. nov. is described from the Hauterivian; this displays typical shell structure of the group, retained by living Verrucidae. Finally, four species of Zeugmatolepadidae, subfamily Martillepadinae, are recorded from the Hauterivian, including Martillepas hausmanni (Koch and Dunker, 1836), M. decoratus sp. nov., M. auriculum sp. nov. and Etcheslaepas borealis (Collins, 1990). The Hauterivian fauna from Hannover shows affinities both with Late Jurassic and later Cretaceous (Aptian-Cenomanian) forms, and includes the earliest scalpellids, unilateran (Pedupycnolepas) and Cretiscalpellum species known. It constrains the age of the Cretaceous cirripede evolutionary radiation to the earliest Cretaceous.  相似文献   

10.
《Gondwana Research》2016,29(4):1543-1565
Early Cambrian small skeletal fossils (SSFs) are studied and revised from the Zhenba–Fangxian Block of the transitional zone between the Yangtze Block and the South Qinling Terrane. The study reveals a diverse fauna with 47 species of various biological affinities, including the new species Gapparodus gapparites sp. nov. The SSFs are assigned to the newly defined Cambroclavus fangxianensisRhombocorniculum cancellatum Assemblage Zone. Based on the investigated SSF fauna from Zhenba County, Southeast Shaanxi of China and published data, a palaeobiogeographic study is carried out for the Cambrian Stage 3 (equivalent to the Atdabanian–Botoman of Siberia). A hierarchical Pearson similarity cluster analysis of 295 species from 32 regions of the world indicates a distinct palaeobiogeographic pattern with seven faunal provinces. The result is mostly consistent with existing palaeogeographic reconstructions for the early Cambrian. However, it is also shown that the SSF assemblages of the Zhenba–Fangxian Block have low similarity with those of the Yangtze Block. Instead, they share high similarity with those from Armorica, Tarim and the Karatau–Naryn terranes (South Kazakhstan/North Kyrgyzstan). The Yangtze Block has a unique SSF assemblage dissimilar to most of other regions. The Terreneuvian–Cambrian Stage 3 sedimentary sequence of the Zhenba–Fangxian Block is more consistent with that of the South Qinling Terrane. Besides, sedimentary Ediacaran manganese ore deposits and Cambrian barite/witherite deposits have unique distribution pattern on the Zhenba–Fangxian Block. Derived from the profound dissimilarities in faunal composition, sedimentary sequence and distribution of sedimentary ore deposits, we hypothesize that during the Neoproterozoic–Cambrian transition, the Zhenba–Fangxian Block might have been an independent terrane and more distant from the Yangtze Block. The palaeobiogeographic analysis of SSFs also indicates a closer alliance between Avalonia and Siberia. It corroborates the palaeogeographic reconstruction of North China at the margin of Gondwana, in the vicinity of Australia, Antarctica, and Armorica.  相似文献   

11.
12.
Ostracod from the upper Lower to Middle Devonian rocks of the Argentine Precordillera Basin (Talacasto and Punta Negra formations) are studied. One new genus Pircawayra nov. gen., and five species (including three new: Pircawayra gigantea nov. gen. and sp., Lapazites trinodis nov. sp. and Keslingiella? teresae nov. sp.) are defined. The recorded ostracod fauna closely resembles that coeval from Bolivia and South Africa, exhibiting a remarkable endemism, not only at the genus level, but also at the species level. In addition to its low-diversity, the Malvinokaffric ostracod association is also characterized by having large, thick, coarsely ornamented and swollen valves. The similar ostracod composition from the Andean and South African basins suggests faunal exchange between these two areas. Based on the ostracod faunas, the Malvinokaffric Realm is clearly recognizable at least up to the Middle Devonian.  相似文献   

13.
The significance of trilobites described from six cores from the Kalladeina 1 drillhole from the Warburton Basin, northeastern South Australia is discussed. The oldest are from a dark grey shale of Core 16 from a depth of 3453.7–3455.8 m; they are of possible early Drumian (Cambrian Series 3, middle Cambrian) age. The youngest come from a dark grey shale of Core 4 at a depth of 2017.2–2022.04 m. This fauna contains the trilobites Asaphellus? sp., Yosimuraspis sp., Conophrys sp. and Protopliomerops? sp. thus indicating a Tremadoc (earliest Ordovician) age. These are the youngest known trilobites from the Warburton Basin and the youngest known in South Australia.  相似文献   

14.
关于双壳类的地质时代延限,前人认为是从奥陶纪或中寒武世至现代。Barrande 和Walcott 将纽约州早寒武世的Fordilla troyensisModioloides prisca等属种作为双壳类描述,但Ulrich和Bassler认为该属种是节肢动物门的甲壳类,而非软体动物门的瓣鳃类(双壳类)。  相似文献   

15.
中国南方泥盆系发现颗石藻   总被引:1,自引:0,他引:1       下载免费PDF全文
颗石藻作为一种超微远洋浮游生物,出现于侏罗纪里阿斯世(Lias),繁盛于晚白垩世至第三纪。最近又有所进展。哈克(Hag,1981)面告,最老的颗石藻出现于石炭纪和二叠纪。本文所报道之颗石藻发现于晚泥盆世,是截至目前为止最老的颗石藻化石。 颗石藻演化迅速,分布广泛,形态特征明显,而且数量众多,对划分对比海相地层有一定的意义。本文只对研究区所采标本的颗石藻进行鉴定、描述和分类。  相似文献   

16.
Historical published works on the fossil fauna of the Llanberis Slates Formation in Gwynedd, North Wales, concentrated on the endemic trilobite Pseudatops viola (Woodward, 1888), and placed the formation towards the top of Stage 3 (Series 2) of the Cambrian chronostratigraphy.The impression given was that the fauna is not particularly diverse and fossils are rare. However, recent collecting has produced a comprehensive fauna of sponges, hyolithids and diverse arthropods including over 250 trilobite specimens from two localities of the uppermost Green Slate horizon. Among them are examples of the endemic trilobite Pseudatops viola, sufficiently well preserved to enable a reappraisal of its status. The most abundant trilobite is a form of Strenuella (cf. strenua), but the collection includes previously unrecorded eodiscoid trilobites and specimens representing unrecorded and potentially new taxa. These additions result in the most comprehensive lower Cambrian trilobite assemblage yet described from Wales, and place it in the lower part of Stage 4, Series 2 in standard global terms.  相似文献   

17.
Three new caddisflies species are described and illustrated from the mid-Cretaceous Burmese amber: Wormaldia cretacea sp. nov., W. resina sp. nov. (Philopotamidae) and Neureclipsis burmanica sp. nov. (Polycentropodidae). Palerasnitsynus ohlhoffi (Psychomyiidae) is re-described based on new fossils. Wormaldia are common in Burmese amber, and its diversity shows that this genus had very ancient origin and diversified at least during the mid-Cretaceous. N. burmanica sp. nov. is the oldest record of Neureclipsis, revealing this genus originated at least in the mid-Cretaceous. So far, six extinct species representing the small Order Trichoptera have been found in Burmese amber.  相似文献   

18.
云南省晋宁梅树村地区下寒武统发现颗石藻化石   总被引:2,自引:0,他引:2       下载免费PDF全文
 在我国云南省晋宁县梅树村地区下寒武统发现了颗石藻化石,计有两个新属四个新种:微细管碟星藻属(新属)(Microtubediscoaster gen.nov.)包括昆阳微细管碟星藻(新属新种)(Microubediscoaster kunyangensis gen.et sp.nov.)和蜂巢微细管碟星藻(新属新种)(Microtubediscoaster honeycomb gen.et sp.nov.);始四枝碟星藻属(新属)(Eotetralithus gen.nov.)包括银杏叶始四枝碟星藻(新属新种)(Eotetralithus ginkgolabulatus gen.et sp.nov)和管柱始四枝碟星藻(新属新种)(Eotetrailthustube Pillar gen.et sp nov.).下寒武统的颗石藻化石是迄今为止世界各国已报道的最老的颗石藻化石。  相似文献   

19.
Paper describes six species of neocheilostomine bryozoans occurring in the Middle Eocene-Early Miocene rocks of Western Kachchh, Gujarat, India. Taxa belong to the families Quadricellariidae Gordon, 1984, Vinculariidae Busk, 1852 and Poricellariidae, Harmer, 1926. Of these three species are new. These are Vincularia feddeni nov sp. Poricellaria waioriensis nov sp. and Poricellaria sakurkari nov sp. Two species, Nellia tenella (Lamarck, 1816) and Vincularia kutchensis (Tewari & Srivastava, 1967) already known from this region, are further reported here. Poricellaria complicata (Reuss, 1869)? is reported for the first time and indicates oldest record from India so far. Phylogenetic analysis using PAST programme indicates that Poricellariids and Vinculariids have not evolved from the same ancestor Nellia tenella (Lamarck, 1816)  相似文献   

20.
The Middle Cambrian succession of the Parahio Valley in general and Debsakhad section in particular is dominated by trilobites. Genus Opsidiscus, along with other trilobite forms dominates the lower Middle Cambrian succession. In the present study two new species of Opsidiscus, Opsidiscus wadiai and Opsidiscus srikantiai are reported from the lower Middle Cambrian succession of Debsakhad section. The species were differentiated on their morphological features and their multivariate analysis. The multivariate analysis applied here is used as a supplement method to qualitative analysis in order to differentiate between the cranidial characters of Opsidiscus. The qualitative study of each species studied individually shows more or less close affiliation as is observed by different quantitative methods. The presence of Opsidiscus has a great stratigraphic significance in this region, as they first appear from informal Stage 5 of Series 3 and goes up to the Drumian Stage of Series 3 of the Cambrian System in the Debsakhad section, which helps to correlate this section with other well known sections of the Middle Cambrian.  相似文献   

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