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1.
After a slow recovery from the end-Permian extinction during the Early Triassic and rapid radiation in the Middle Triassic, evolution of organisms reached a new peak phase in the Late Triassic. The Guanling Biota from the Wayao Member (conodont Paragondolella polygnathiformis Zone), Falang Formation, Xinpu, Guanling County, Guizhou Province, southwestern China corresponds to this peak that marks the full recovery from the end-Permian extinction of marine ecosystems. The biota is of high diversity, containing well preserved and completely articulated skeletons of vertebrates comprising marine reptiles, fishes, and invertebrates including crinoids, ammonites, bivalves, and other fossils, and is one of the best examples of marine ecosystem records in life history. The fossil marine reptiles and crinoids are most significant in this biota, especially the marine reptiles, which provide an important link between the Triassic Pacific and Tethys, and between Triassic basal forms and the Jurassic-Cretaceous marine top predators. The most remarkable fossils are the large completely articulated ichthyosaur skeletons up to and more than 10 m, and the first recorded thalattosaurs and placodonts in China. Following our review, of the 17 named reptilian taxa the eight listed here are considered to be valid: three ichthyosaurs (Qianichthyosaurus zhoui Li, 1999; Guizhouichthyosaurus tangae Cao and Luo in Yin et al., 2000, Guanlingsaurus liangae Yin in Yin et al., 2000), three thalattosaurs (Anshunsaurus huangguoshuensis Liu, 1999, Xinpusaurus suni Yin in Yin et al., 2000, Xinpusaurus kohi Jiang et al., 2004), and two placodonts (Sinocyamodus xinpuensis Li, 2000, Psephochelys polyosteoderma Li and Rieppel, 2002). Mixosaurus guanlingensis Cao in Yin et al., 2000 might be a junior synonym of Qianichthyosaurus zhoui Li, 1999, and Cymbospondylus asiaticus Li and You, 2002 and Panjiangsaurus epicharis Chen and Cheng, 2003 might be junior synonyms of Guizhouichthyosaurus tangae Cao and Luo in Yin et al., 2000. It needs to re-describe the holotypes after a complete preparation for clarifying the taxonomic status of Typicusichthyosaurus tsaihuae Yu in Yin et al., 2000, Xinpusaurus bamaolinensis Cheng, 2003, Neosinosaurus hoangi (Zhou in Yin et al., 2000), Wayaosaurus geei Zhou in Yin et al., 2000, Wayaosaurus bellus Zhou in Yin et al., 2000 and Placochelys ? minutus Yin and Luo in Yin et al., 2000.  相似文献   

2.
The Triassic?Jurassic (Tr?J) boundary marks a major extinction event, which (~200 Ma) resulted in global extinctions of fauna and flora both in the marine and terrestrial realms. There prevail great challenges in determining the exact location of the terrestrial Tr?J boundary, because of endemism of taxa and the scarcity of fossils in terrestrial settings leading to difficulties in linking marine and terrestrial sedimentary successions. Investigation based on palynology and bivalves has been carried out over a 1113 m thick section, which is subdivided into 132 beds, along the Haojiagou valley on the southern margin of the Junggar Basin of the northern Xinjiang, northwestern China. The terrestrial Lower Jurassic is conformably resting on the Upper Triassic strata. The Upper Triassic covers the Huangshanjie Formation overlaid by the Haojiagou Formation, while the Lower Jurassic comprises the Badaowan Formation followed by the Sangonghe Formation. Fifty six pollen and spore taxa and one algal taxon were identified from the sediments. Based on the key-species and abundance of spores and pollen, three zones were erected: the Late Triassic (Rhaetian) Aratrisporites?Alisporites Assemblage, the Early Jurassic (Hettangian) Perinopollenites?Pinuspollenites Assemblage, and the Sinemurian Perinopollenites?Cycadopites Assemblage. The Tr?J boundary is placed between bed 44 and 45 coincident with the boundary between the Haojiagou and Badaowan formations. Beds with Ferganoconcha (?), Unio?Ferganoconcha and Waagenoperna?Yananoconcha bivalve assemblages are recognized. The Ferganoconcha (?) bed is limited to the upper Haojiagou Formation, Unio?Ferganoconcha and Waagenoperna?Yananoconcha assemblages are present in the middle and upper members of the Badaowan Formation. The sedimentary succession is interpreted as terrestrial with two mainly lake deposit intervals within Haojiagou and Badaowan formations, yielding fresh water algae and bivalves. However, the presence of brackish water algae Tasmanites and the marine?littoral facies bivalve Waagenoperna from the Badaowan Formation indicate that the Junggar Basin was influenced by sea water caused by transgressions from the northern Tethys, during the Sinemurian.  相似文献   

3.
正Objective The Yanyuan and Sichuan Basins,located at the southwestern margin of the Yangtze Block,are separated by the Kangdian Oldland.The provenance of the Upper Triassic sediments deposited in the Sichuan Basin has been extensively studied much based on detrital zircon UPb geochronology (Zhang et al,2016;Zhu et al.,2017;Yan et al.2019).However,the provenance of the Upper  相似文献   

4.
In the Yanliao area, the occurrence of the Nestoria-Keratestheria fauna and the Eoparacypris- Luanpingella-Darwinula assemblage in the Dabeigou Formation s.s., a Rb-Sr isochron age of 145.2 Ma for the Baiqi Formation and a complete stratigraphic sequence-all this proves that the Lycoptera-bearing bed overlies the Upper Jurassic. The Jehol fauna comprises the primitive Trigonioidids fauna, Eosestheria fauna, Lycoptera fauna et al., and their own laws of evolution expound that they belong to Cretaceous faunas. The associations of Eosestheria with Yanjiestheria, Lycoptera with Eosestheria, and Kuntulunia with Yanjiestheria as well as the occurrence of early angiosperms and sporo - pollen in the Fuxin Formation and its equivalents also demonstrate that the Lycoptera-bearing, bed should be assigned to the Cretaceous. The confirmation of the existence of Aucellina in the Jixi Group and the correlation of Trigonioidids and Cypridids with those in the equivalent strata of Japan and Western Europe have also been  相似文献   

5.
Three taxa of Late Cretaceous aquatic angiosperms,Queruexia angulata(Lesq.)Krysht., Cobbania corrugata(Lesq.)Stockey et al.and Nelumbites cf.extenuinervis Upchurch et al.from Jiayin of Heilongjiang,NE China,are described in detail.Among them,Cobbania and Nelumbites from the Upper Cretaceous in China are reported for the first time.The aquatic angiosperm assemblage of Queruexia-Cobbania-Nelumbites appears to imply a seasonal,warm and moist environment in the Jiayin area during the Santonian-Campanian time.  相似文献   

6.
Three taxa of Late Cretaceous aquatic angiosperms, Queruexia angulata (Lesq.) Krysht., Cobbania corrugata (Lesq.) Stockey et al. and Nelumbites cf. extenuinervis Upchurch et al. from Jiayin of Heilongjiang, NE China, are described in detail. Among them, Cobbania and Nelumbites from the Upper Cretaceous in China are reported for the first time. The aquatic angiosperm assemblage of Queruexia-Cobbania-Nelumbites appears to imply a seasonal, warm and moist environment in the Jiayin area during the Santonian-Campanian time.  相似文献   

7.
During the Middle Triassic a great turn took place in thedevelopment of sedim entary basin of South China.Followingthe final suture of Cathaysia block with Yangtze block (in-cluding the L ower Yangtze region) ,Yangtze block matchedcompletely the North China block (Yin et al.,1999) ,whilethe extensive Indosinian m ovementwreaked havoc in the east-ern Tethys.Then the sediments in the main part of SouthChina transformed gradually from marine to terrestrial.As aresult the most remarkable cha…  相似文献   

8.
The Kurosegawa belt forms a relatively narrow terrane that can be traced continuously throughout southwest and central Japan. The major constituent continental fragments of the Kurosegawa belt include Early Paleozoic granitic rocks, high-grade metamor-phic rocks, Carboniferous metamorphic rocks (epi-dote-amphibolite facies), Triassic-Early Jurassic metamorphic rocks (pumpellyite-actinolite facies), serpentinites of unknown age, Silurian–Devonian volcanoclastic rocks intercalated with limestones, and Permian–Jurassic shallow marine sediments (e.g., Ichikawa et al., 1956; Maruyama et al., 1984; Faure, 1985; Yoshikura et al., 1990; Aitchison et al., 1991, 1996; Hada et al., 1992, 2001; Isozaki et al., 1992). These diverse rock suites are highly disrupted, form-ing lenticular bodies within the Late Permian accre-tionary complex (AC) which collectively are covered by younger (Cretaceous) marine to brackish water sediments (e.g., Aitchison et al., 1991; Isozaki et al., 1992). We characterize the tectono-stratigraphic ar-chitecture and low-grade metamorphism of the accre-tionary complex preserved in the Kurosegawa belt of the Kitagawa district in eastern Shikoku, Southwest Japan, in order to understand its internal structure, tectono-metamorphic evolution, and assessments of displacement of continental fragments within the complex.  相似文献   

9.
The study of the physicochemical behaviour of colloids and particles in nature has emerged as a scientific problem of critical importance because of the widespread acknowledgement of their significance in controlling the speciation and fate of essential nutrients and contaminants in the aquatic and soil environments (Ledin et al., 1995; Lead et al., 1999, Doucet et al., 200 l; McCarthy et al., 1989; Koterba et al., 1993; Kretzschmar et al., 1999). Se'quaris and Lewandowski (2003) developed a method based on sedimentation and centrifugation steps to fractionate agricultural top soils after suspension in water. However, progress in the field has been limited by the lack of appropriate techniques for the isolation and characterization of colloids and particles in their native form (Lead et al., 1997). The primary difficulties in separation and analysis are colloidal instability and their small size and low concentration. As a result, reliable, unbiased and minimally perturbing methods for sampling and fractionation are primary requirements for the study of colloids and particles if valuable information is to be obtained. In recent years, cross-flow ultra-filtration (CFUF) has become one of the most commonly used techniques for collecting and separating freshwater and marine colloids and particles (Petrus evski et al., 1995; Gustafsson et al., 1999; Benoit et al., 1999; Sigg et al., 2000; Gue'guen et al., 2002; Benedetti et al., 2003). CFUF has hitherto been used for studies of the biogeochemical cycling of a variety of elements, such as carbon (Benner et al., 1992; Santschi et al., 1998), radionuclides (Moran et al., 1992), trace metals (Reitmeyer et al., 1996) and nutrients (Bauer et al., 1996). The purpose of this study was to develop a protocol to fractionate particles in soil, to measure particle size distributions and to quantify chemical characteristics within different particle size fractions.  相似文献   

10.
<正>1 Introduction The sandstone of Shanxi formation in Upper Paleozoic in the north of Ordos basin is very tight,thin,quick lateral changes and strong heterogeneity.It is a lithologic trap and subtle gas reservoir.It is very difficult to analyze gas enrichment factors and predict high yield zone(Hao et al.,2011;Zhao et al.,2012).The tight sandstone of Shanxi formation in Upper Paleozoic Permian in Linxing area in  相似文献   

11.
本文报道了浙江东阳发现的中国第2个翼龙足迹化石点, 也是亚洲发现的第8个翼龙足迹化石点。化石足迹产于晚白垩世早期方岩组的紫红色泥质粉砂岩中。发现有3个手的印迹和1个右足印。手的印迹的长宽分别为6.5 cm 和4cm. 非对称具有3个指的印迹。足迹9 cm长和1.5 cm宽。该足迹不同于以前发现的, 可能代表一新的类型。除了翼龙足迹外, 还发现鸟类、小型兽脚类、鸟脚类及蜥脚类脚印, 形成一个丰富的动物群, 它的发现为研究该地区的古生态环境及古地理具有重要意义。同时为以后在该地区发现这些造迹动物的骨骼化石提供了重要依据。  相似文献   

12.
关岭海生爬行动物群研究评述   总被引:1,自引:1,他引:1       下载免费PDF全文
赵丽君  吴慧珍 《地质论评》2007,53(3):318-322
贵州省关岭县上三叠统海生爬行动物化石自1999年被发现以来,先后有12属17种被报道,其中包括我国首次发现的檑齿龙类和海龙类。由于化石的保存状况以及标本的修理难度等多种原因,已经发表的材料中包括了大量的同物异名现象以及无效的属种。通过对已发表文献的全面回顾和总结,确认了该动物群中命名有效的5属6种——即周氏黔鱼龙、黄果树安顺龙、新铺中国豆齿龙、多板砾甲龟龙、孙氏新铺龙和巴毛林新铺龙,指出两种尚未命名的大型海龙类和鱼龙类的存在,这一组合基本反映了关岭三叠纪海生爬行动物群的真实面貌。同时提出了关岭海生爬行动物化石研究过程中,标本的真实性、化石修理及学术沟通等方面存在的问题。  相似文献   

13.
The Middle Triassic fossil reptile localities near Bayreuth (Bavaria, southern Germany) consist of shallow marine autochthonous glauconitic marls and terebratulid-rich tempestite carbonates of the newly defined Bindlach and Hegnabrunn formations. Single bones and incomplete skeletons of marine reptiles have been recorded in bone beds within in the Illyrian and Fassanian stages. These include the remains of the sauropterygians Neusticosaurus sp., Lariosaurus cf. buzzii [1], Nothosaurus mirabilis [2], Paranothosaurus giganteus [2], Placodus gigas [3], Cyamodus rostratus [4], Cyamodus münsteri [5], Pistosaurus longaevus [6], and ichthyosaursOmphalosaurus sp., and Shastasaurus sp. or proterosaur Tanystrophaeus conspicuus [7]. New skeletal reconstructions are based on the osteological analysis of three dimensionally preserved bones and skeletal remains. The large number of marine endemic placodont macroalgae feeders (P. gigas) in the Bayreuth sites coincides with the presence of invertebrate palaeocommunities that are characteristic of macroalgae meadow paleoenvironments. Most of the reptile species and genera from the Bayreuth localities also occur in beds of similar ages from the Monte San Giorgio (Switzerland/Italy) or Perledo (Italy) lagoonal areas. Ichthyosaurs and pistosaurs were adapted for open marine conditions, and may have migrated from the Panthalassa Oceans into the shallow marine Germanic Basin to reproduce, whereas placodonts and many other sauropterygians seem to have lived permanently in those shallow marine habitats, with large squamates and thecodont or smaller archosaurs in coastal areas.  相似文献   

14.
贵州安顺龙宫戴帽山是新发现的一处海生爬行动物化石产地,通过在该地区开展化石发掘与修理工作,共获取3块保存精美的海生爬行动物化石。上述3块海生爬行动物化石均归属于鳍龙超目(Sauropterygia),基于古生物地层学与沉积学的研究,判断其时代为中三叠世安尼期。化石产地的古地理位置位于扬子台地西南缘,是滇黔桂台地边缘相区内首个产出完整海生爬行动物化石的产地。笔者等的研究成果对三叠纪海生爬行动物系统演化、重塑当时古环境、中三叠世安尼期辐射强度等方面具有十分重要的意义,并为海生爬行动物的古地理分布提供了新材料。  相似文献   

15.
冉维宇  史振华  胡歆睿  秦燕娇  蒋良兵  邓小杰  贺箫  喻美艺  罗永明 《地质论评》2023,69(3):2023030021-2023030021
贵州安顺龙宫戴帽山是新发现的一处海生爬行动物化石产地,通过在该地区开展化石发掘与修理工作,共获取3块保存精美的海生爬行动物化石。上述3块海生爬行动物化石均归属于鳍龙超目(Sauropterygia),基于古生物地层学与沉积学的研究,判断其时代为中三叠世安尼期。化石产地的古地理位置位于扬子台地西南缘,是滇黔桂台地边缘相区内首个产出完整海生爬行动物化石的产地。本文的研究成果对三叠纪海生爬行动物系统演化、重塑当时古环境、中三叠世安尼期辐射强度等方面具有十分重要的意义,并为海生爬行动物的古地理分布提供了新材料。  相似文献   

16.
李亚  纪占胜  武桂春  姚建新  王玉净 《地球科学》2018,43(11):3932-3946
前人研究表明西藏南羌塘盆地存在中三叠世地层,然而一直以来缺乏确凿的古生物化石证据.在西藏改则县古姆乡座倾错地区原被划为晚三叠世日干配错组的地层中测制了两条剖面,在硅质岩样品中分析和鉴定出18属33种(含未定种)放射虫化石,主要分子包括Cryptostephanidium longispinosum(Sashida)、Eptingium manfredi Dumitrica、Falcispongus falciformis Dumitrica、Hindeosphaera spinulosa(Nakaseko et Nishimura)、Muelleritortis firmum(Gorican)、Oertlispongus inaequispinosus Dumitrica,Kozur et Mostler、Paroertlispongus chinensis(Feng)、Paroertlispongus hermi(Lahm)、Paroertlispongus weddigei Lahm、Paurinella aequispinosa Kozur et Mostler、Pseudostylosphaera coccostyla(Rüst)、Pseudostylosphaera compacta(Nakaseko et Nishimura)、Pseudostylosphaera gracilis Kozur et Mostler、Pseudostylosphaera japonica(Nakaseko et Nishimura)、Pseudostylosphaera nazarovi(Kozur et Mostler)、Pseudostylosphaera tenue(Nakaseko et Nishimura)、Triassocampe imitata Bragin、Triassospongosphaera triassica(Kozur et Mostler).座倾错放射虫化石组合指示这段地层时代为中三叠世安尼期晚期-拉丁期早期.结合之前的工作积累,将南羌塘盆地三叠系划分为表示稳定型浅海相碳酸盐岩沉积的下三叠统孜狮桑组、表示半深海-深海相碎屑岩-硅质岩沉积的中三叠统座倾错组、上三叠统日干配错组以及上三叠统-下侏罗统萨门熊组.该发现为了解中三叠世南羌塘地区的真实面貌提供了地层学和古生物学证据,也进一步证明中三叠世南羌塘盆地不是陆地剥蚀区或隆起区,而是一种半深海-深海相沉积区.   相似文献   

17.
本文描述的双壳类化石共5属13种,分别采自喀喇昆仑山地区9个地点,分别采目下三叠统下河尾滩群、中三叠统上河尾滩群、上三叠统克勒青河组.所描述的该区化石绝大多数为首次报道.早三叠世双壳类动物群无疑地属于南特提斯区,中晚三叠世的双壳类及沉积具有浊流沉积特征,并根据构造研究结果,处于南特提斯区.  相似文献   

18.
This paper briefly reviews the Triassic marine reptile fossils in Guizhou Province, especially the fossils that have been recently found in the Guanling area. Based on three sections at Guanling and Xingyi, Guizhou Province and Luoping, Yunnan Province, four horizons with vertebrate fossils are recognized in the Middle and Upper Triassic of this area; They are from bottom to top: Member I and Member II of the Guanling Formation, and the Zhuganpo Member and the Wayao Member of the Falang Formation.  相似文献   

19.
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