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1.
Abstract: The Middle Triassic Panxian fauna is a physical marker and representative record of the rapid recovery of the Triassic marine ecosystem following the Early Triassic stagnant stage after the end-Permian mass extinction. Ten marine reptile taxa have been found from the 1.82–2.10 m-thick fossiliferous level in the Upper Member of the Guanling Formation, which can be subdivided into three marine reptile beds through the analysis on the stratigraphic distributions of fossil reptiles. The Lower Reptile Bed yields the sauropterygians Placodus inexpectatus Jiang et al., 2008 and Lariosaurus hongguoensis Jiang et al., 2006, the ichthyopterygians Xinminosaurus catactes Jiang et al., 2008 and Phalarodon cf. Phalarodon fraasi Merriam, 1910, associated with Mixosaurus panxianensis Jiang et al., 2006, representing a stage of predominance of durophagous taxa. In this bed, the large complete skeletons may reach up to 2.3 m in length, and lithofacies and chemostratigraphic analyses indicate a relatively deep carbonate platform with an oxic water environment near the bottom, as well as a rising sea level. The Middle Reptile Bed yields the sauropterygian Nothosaurus yangjuanensis Jiang et al., 2006 and the archosaur Qianosuchus mixtus Li et al., 2006, associated with Mixosaurus panxianensis Jiang et al., 2006. The fossils in this bed are characterized by its pincering dentition and large overall body size, with the largest possibly exceeding 3 m in length. This bed might represent a time of deepest basin with relatively anoxic condition near the bottom. The Upper Reptile Bed yields the sauropterygians Wumengosaurus delicatomandibularis Jiang et al., 2008, Keichousaurus sp., the protorosaur Dinocephalosaurus orientalis Li, 2003, and the ichthyopterygian Mixosaurus panxianensis Jiang et al., 2006. In this bed, reptilian taxa characterized by suction feeding appeared, and most are less than 1 m long. This bed corresponds to a period of decreasing water depth.  相似文献   

2.
This paper gives a brief report on the new occurrence of the Early CambrianQiongzhusi' an Chengjiang fauna in the Haikou area, Kunming and its assemblage feature andthe stratigraphic section of the horizon yielding these fossils. Eight genera and 8 species ofTrilobitoidea are described here, embracing Leanchoilia asiatica Luo et Hu (sp. nov.), Yohoiasinensis Luo et Hu (sp. nov.), Zhongxinia speciosa Luo et Hu (gen. et sp. nov.), Xandarellaspectuculum Hou et al., Dianchia mirabilis Luo et Hu (gen. et sp. nov.), Kuamaia lata Hou,Retifacies longispinus Luo et Hu (sp. nov.) and Sinoburius lunaris Hou et al.  相似文献   

3.
INTRODUCTIONThe anchorage of geomaterial , including shaftanchors and prestressed tendons ,is usually used ingeotechnical engineering. Owing to various advanta-ges ,these two anchorage types are widely used instructures in China ( Cao et al ., 2003 ; Fu et al .,1999 ;Lu et al .,1998 ; Li et al .,1995) . Shaft an-chors can be classifiedinto three kinds by the forceinthe shaft and cement grout :tensile ,press ,and sheartype (Lu et al .,1998) . The tensile type is the mostpopular in China…  相似文献   

4.
1 IntroductionIt is widely accepted that the collision of India withEurasia proceeded from "soft" to "hard" phases between c.65-70 Ma and c. 45 Ma (Yin and Harrison, 2000; Flower etal., 2001; Dong, 2002; Mo et al., 2003; Zhou et al., 2004,and references therein). Obviously, it is important tounderstand what kind of process took place at the depth ofthe Tibetan Plateau and its timing and geodynamicenvironment responding to the India-Eurasia continentalcollision. The giant Gangdise granito…  相似文献   

5.
<正>A series of Ni-Cu sulfide deposits hosted in Early Permian mafic-ultramafic complexes occur along the~500km long linear Huangshan-Jingerquan belt in the East Tianshan at the southern margin of the Central Asian Orogenic Belt(Fig.1)(Zhou et al.,2004;Song and Li,2009;Song et al.,2011;Qin et al.,2011;Deng et al.,2014).Questions for genetic link between these deposits and the  相似文献   

6.
1 Introduction The Jiufotang Formation is one of the most fossil- productive Early Cretaceous deposits of China. It overlies the famous Yixian Formation from which many important taxa were found (Ji et al., 2004; Chang et al., 2003; Zhou et al., 2003). In addition to other vertebrates, pterosaurs, the first flying reptiles in Earth history, are also abundant in the Jiufotang Formation. At present, nine species belonging to five genera have been reported from the Jiufotang Formation. The…  相似文献   

7.
The latest Cretaceous strata of the Jiaolai Basin were studied in two scientific cores,including LK-1 drilled by the Institute of Geology,Chinese Academy of Geological Sciences(Li et al.,2018;Li et al.,2020),and JK-1 drilled by the Shandong Institute of the Geological Survey and Institute of Geology,Chinese Academy of Geological Sciences(Xu et al.,2017).However,outcrop sections were poorly studied,and the latest Cretaceous charophyte flora in particular had not previously been adequately documented from outcrops in the Jiaolai area.  相似文献   

8.
1 Introduction Voluminous literature has resulted from study of the geology and tectonic evironments of post-orogenic granitoids in eastern Tianshan (He et al., 1995; Han et al., 1997; Gu et al., 1999, 2001; Li et al., 2003; Chen et al., 2004). Previous contributions (Hu et al., 1997; Li et al., 2003) indicate that major events of continental collision in northern Xinjiang occurred around 300 Ma. Then, the tectonics converted from compression to extension, resulting in the uplifting of th…  相似文献   

9.
正1 Introduction As one of the major zooplanktonic organisms in the Ordovician and Silurian marine ecosystems,graptolites played a unique role in the GOBE (Great Ordovician Biodiversification Event) and underwent a considerable variation of diversities both in lifestyle and in speciation through the Ordovician (Sadler et al.,2011;Cooper et al.,2014).Graptolites are among the early  相似文献   

10.
Abundant phosphatized acritarchs are preserved in the late Precambrian （Ediacaran） Doushantuo Formation at Weng＇an, Guizhou Province, southwest China. Most of them are large with various spinous ornaments and multilayered outer walls. The general characters of these fossils are quite similar to those found from the homochronous deposits of the Yangtze Gorges, southern China. Therefore the Doushantuo Formation in the Weng＇an area can be correlated directly with the Doushantuo Formation of the Yangtze Gorges. Four species in four genera, including two new genera, two new species and one uncertain species are systematically described for the first time from the studied locality. The taxa are Bacatisphaera baokangensis Zhou, Brasier et Xue, 2001, Taeniosphaera doushantuoensis gen. et sp. nov., Rugospinasphaera speciosa gen. et sp. nov. and Meghystichosphaeridium sp. The new data enriches the famous Weng＇an biota, especially the marine microplankton flora in the Ediacaran Doushantuo Formation.  相似文献   

11.
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   

12.
关于创口海百合(Traumatocrinus)的分类、分布及古生态   总被引：1，自引：0，他引：1  
在中国贵州关岭地区晚三叠世(卡尼期)小凹组(=瓦窑组)海生爬行动物和海百合化石库中产有大量完好保存的创口海百合(Traumatocrinus)(棘皮动物门,海百合纲)化石。根据对此类海百合分类、分布和形态构造及古生态的研究,特别是大量完好保存、且附着在漂浮木头上的群体化石标本的发现,进一步证明这种外形似海百合花的创口海百合营假浮游的生活方式。这类特化的海百合分枝起源于另一类底栖中三叠世石莲海百合科,很快占领了卡尼期初期的生态境,至卡尼期末创口海百合衰退以后,它的生态境在诺利期时为形态发生的趋同变异的链海百合(Seirocrinus)和五角海百合(Pentacrinites)所占领。  相似文献   

13.
何竞  虎艺薇  张娣  沈越峰 《地质论评》2023,69(3):2023030018-2023030018
新铺龙是产于我国西南地区的海龙目的一个属,最早发现于贵州省关岭晚三叠世卡尼期小凹组地层。虽然新铺龙材料众多,但其未成年个体骨骼学特征及个体发育模式并未被详细地记述。本文报道了一个保存完好的孙氏新铺龙未成年标本,是目前发现最小的完整的孙氏新铺龙个体,标本产自贵州省关岭县新铺乡。依据其体长小于正型标本的一半,头骨长度和躯干比值大,头骨骨缝清晰等特征,判断该标本为孙氏新铺龙的幼年个体。新标本补充了孙氏新铺龙幼年个体的形态学信息,如上颞骨内侧突短于外侧突,翼骨无牙齿发育,神经弓与椎体未融合,尺骨两端微凸,五边形坐骨等。此外,结合已发表的新铺龙标本数据进行统计分析发现,该物种吻部相对头部呈负异速生长,证明了吻部占头骨比例的大小属于新铺龙种内个体发育差异,而并非之前所认为的新铺龙种间差异。  相似文献   

14.
贵州关岭生物群中植物化石的发现及其意义   总被引：4，自引：1，他引：4  
关岭生物群是近年来在我国贵州关岭地区瓦窑组中发现的一个十分重要的生物群 ,其中的植物化石经研究计有 Equisetites cf.arenaceus(Jaeger) Bronn.、Ctenozamitessarrani Zeiller。依据植物化石 C.sarrani常见于晚三叠世和 E.cf.arenaceus系似木贼属中较古老的类型 ,指出含植物化石的地层时代为晚三叠世卡尼期。瓦窑组系海相沉积 ,其中的植物化石无疑为异地埋藏 ,但从化石通常保存尚好来看 ,估计搬运的距离不会很远 ,它们可能是从距海岸不远的陆地被河流带到较平静的海湾或海槽而沉积下来的。此外 ,从该组植物茎干化石具清楚的年轮分析 ,推测卡尼期时 ,贵州关岭一带为非热带雨林地区 ,一年中气候不是四季如一 ,而是有明显的季节变化  相似文献   

15.
贵州关岭生物群中发现完美的植物化石   总被引：5，自引：1，他引：5  
关岭生物群是指贵州关岭一带以大量海生爬行动物和海百合为特色的多门类化石群［１］，现已成为中国重要的化石宝库之一，但以往一直没有植物化石的报道。近些年来，笔者等在该地产海生爬行动物的同一层位中首次发现较多的植物化石，经鉴定为CtenozamitessarraniZeiller和Equisetitesare－naceus（Jaeger）Bronn．。这些植物化石的发现不仅增添了关岭生物群的组成内容，而且为海生爬行动物时代的确定提供了新的证据。植物化石产于关岭县新铺乡小凹组（原称“瓦窑组”）近底部。小凹组主要系一套海相不纯碳酸盐岩沉积，由灰、深灰、灰黑色…  相似文献   

16.
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   

17.
Huaqing area is an important area for oil and gas exploration and development in the Ordos Basin, within which, the Chang 9 oil group of Triassic Yanchang Formation is one of the main intervals for exploration and development (Zhang et al., 2011). Fluid inclusions record abundant oil and gas accumulation information and important oil and gas migration and accumulation history information(Parnell et al., 1998; Parnell, 2010; Jiang et al., 2018). The occurrence, distribution and intersection of the fluid inclusions in diagenetic minerals were observed under microscope. The accurate formation periods of inclusions are key to determine hydrocarbon accumulation periods (Burrus et al., 1985; Zhou et al., 2000; Zhao, 2002). In addition, the fluorescence color and brightness of organic inclusions observed by fluorescence microscopy could be used to roughly identify the oil and gas evolution stages (Zhang et al., 2010). Therefore, the occurrence, distribution and fluorescence characteristics of oil and gas inclusions were important evidence for judging the hydrocarbon accumulation periods. The fluid inclusions in sandstone reservoirs of Chang 9 oil group in Huaqing Area were observed in detail, and the observation results revealed that fluid inclusions were widespread in Chang 9 sandstone and exhibited various types. Through comprehensive analyses, it was considered that the fluid inclusions in Chang 9 sandstone reservoirs indicated three hydrocarbon accumulation periods.  相似文献   

18.
云南罗平中三叠世安尼期生物群的发现及其意义   总被引：15，自引：0，他引：15  
本文介绍了云南罗平地区新发现的罗平生物群的产出层位、生物面貌、保存特征、古地理位置及其研究意义。该生物群产于关岭组二段薄层泥晶灰岩中,地层对比和化石鉴定表明其时代为中三叠世安尼期,以鱼类为主,伴生有爬行类、两栖类（？）、棘皮动物、节肢动物（甲壳类、昆虫等）、双壳类、腹足类以及植物化石;化石保存完好,分布广泛,埋藏方式独特。罗平生物群无论在丰度、分异度及化石保存上都极为罕见和独特,对研究埋藏学、古生态学、古地理以及三叠纪海洋生物尤其是海生爬行类都具有极为重要的意义。  相似文献   

19.
<正>There are many skarn deposits that occur in volcanic rocks as stratiform and lentoid bodies,for example the Lower Yangtze River Valley,Western Tianshan Mountains and Lhasa Terrane in China,the Nuuk in West Greeland and the Austroalpine Alps(e.g.Xv et al.,1984;Appel,1994;Raith and Stein,2000;Wang et al.,2001;Gu et al.,2007;Hou et al.,2011;Zhou et al.,2011;Jiang et al.,2012;Xu et al.,2010;Wang et al.,2012;Yu et al.,2011).Despite  相似文献   

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