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ZHANG HuaQiao & DONG XiPing School of Earth Space Sciences Peking University Beijing China State Key Laboratory of Palaeobiology Stratigraphy Nanjing Institute of Geology Palaeontology Chinese Academy of Sciences Nanjing 《中国科学D辑(英文版)》2009,(6)
Although fossils of Orsten-type preservation represented by Skaracarida and Phosphatocopina were first reported from the Middle and Upper Cambrian in western Hunan, South China in 2005, diversified phosphatocopine species have never been appropriately described and elucidated in terms of their evolutionary relationships. Here, we described two new species of Phosphatocopina, Vestrogothia anterispinata sp. nov. and V. bispinata sp. nov. The evolutionary relationship among all the valid species of Phosphatoco... 相似文献
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乌苏里地区构造新探索 总被引:15,自引:0,他引:15
通过乌苏里地区中苏合作对比研究,对该区的构造有了以下一些新的认识:若干地体的拼贴奠定了东北亚大陆边缘的构造格局,地体的拼贴在时空上是有规律可寻的,这一规律解释了地槽学说对该区构造解释中的疑难问题。通过那丹哈达-比金地体外来岩块的地层对比,建立了一套完整的层序,在利恢复地体漂泊的历史。通过对比还发现苏联远东溪海地区和中国延吉地区可能同是不凯地体二叠纪的活动大陆边缘,三叠纪也经历了共同的演化历史。 相似文献
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四川广元志留系Ludlow统的再研究兼论车家坝组的含义 总被引:3,自引:1,他引:2
四川广元地区志留纪晚期地层曾被划分为金台观组、车家坝组和中间梁组,后被厘定合并为一个组,即车家坝组。通过对岩性组合特征和生物化石群面貌的分析,广元地区晚志留世地层在岩性、生物化石生物群面貌方面具有一致性,赞成将三组归入同一个岩石地层单元——车家坝组,代表近岸、正常浅海(平均浪基面以上)沉积(BA2—BA3)。对比分析表明,该组的牙形刺Ozarkodina crispa应鉴定为Ozarkodina snajdri。这是O.snajdri牙形刺带在中国的首次报道。依据牙形刺化石,车家坝组的时代被修订为中Ludlow世晚期—晚Ludlow世早期。该组上部发现几丁石Sphaerochitina sp.组合,可与O.snajdri牙形刺带和bohemicus tenus-kozlowskii笔石带进行对比。 相似文献
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Middle Jurassic Coptoclavidae (Insecta:Coleoptera:Dytiscoidea) from China:a Good Example of Mosaic Evolution 总被引:2,自引:2,他引:0
<正>Adults of the aquatic coptoclavid beetles(Coleoptera:Adephaga:Dytiscoidea),described from four Middle Jurassic fossil localities in Inner Mongolia and Liaoning in northeastern China,are attributed to Daohugounectes primitives Wang,Ponomarenko and Zhang,2009,which was previously proposed after study of larvae.The generic name Timarchopsis Brauer,Redtenbacher and Ganglbauer,1889 is proposed as a substitute for the preoccupied and junior homonym Necronectes Ponomarenko,1977,non Milne-Edwards,1881. Furthermore,the subfamily name Necronectinae Ponomarenko,1977 is substituted by the available name Timarchopsinae.Daohugounectes is placed into Timarchopsinae because its adults have long,slightly apically widened tibiae and small femoral plates.The adults of this genus differ from those of other Timarchopsinae in the following features:antennae short and widened in the middle part;basal segments of protarsi not cut apically; metaventrite with a triangular plate.The larvae look like somewhat primitive forms in the subfamily Timarchopsinae.In contrast to these primitive larvae,the adults with some advanced characters can be regarded as among the most advanced forms in the subfamily Timarchopsinae,and probably represent a transition between the Timarchopsinae and Charanoscaphinae.Such mosaic evolution within Daohugounectes indicates that the evolutionary process of aquatic beetles is far more complex than previously thought. 相似文献
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微体化石研究中应注意的问题 总被引:1,自引:1,他引:1
多数微体化石仅是生物体的一部分,我国微体古生物学家对生物整体或器官的研究不够,相当多的作者仍在命名大量的形态属种,落后于世界古生物学的发展现状。微体化石是重要的,但微体古生物学家不能过份强调微体化石的重要而忽视与大化石和岩相研究的结合。在化石处理和鉴定过程中,由于微体古生物研究者对混杂问题注意和警惕不够,以至混入现代生物,误作化石。我国小壳化石的新属中,至少有5个属都是现代植物的种子或颖果,有的属 相似文献
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西藏雅鲁藏布江缝合带含有从砾石级到几十平方千米大小的二叠纪灰岩体,它们没有完整的地层层序,与围岩形成混杂或滑杂堆积,长期以来对其来源的解释存在争论。本文通过对灰岩体的动物群类型、古生物地理区系及其岩石学特征等方面进行研究和比较,认为雅鲁藏布江缝合线一带的二叠纪灰岩体总体上都呈现出冈瓦纳冷水型与华夏暖水型动物群混生特点,应形成于相同或类似的沉积环境。根据珊瑚、筵、腕足类等动物群大致分为与南方冈瓦纳大陆北缘内陆棚相动物群比较接近和与更靠近古赤道区的拉萨地块动物群较为接近两种类型,其时代从早二叠世晚期至长兴期不等。灰岩体主要由肉红色或灰色纯生物碎屑灰岩组成,不含或含有很少的陆源碎屑,均孤立地分散于中生代地层中,与围岩往往呈断层接触,断层带或灰岩夹层中经常有玄武岩或其他火山岩。因此,灰岩体可能为位于冈瓦纳大陆北缘外陆棚上小型碳酸盐台地或新特提斯洋最初裂解带上的海山型碳酸盐岩沉积,受后期印度-欧亚大陆板块碰撞作用而成为外来体夹于缝合带的其他海相沉积中。 相似文献
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YANG Qun WANG Yujing YIN Leiming SHU Liangshu LOU Fasheng WANG Bo Nanjing Institute of Geology Palaeontology Chinese Academy of Sciences Nanjing Jiangsu Department of Earth Sciences Nanjing University Nanjing Jiangsu Geological Survey of Jiangxi Province Nanchang Jiangxi 《《地质学报》英文版》2005,79(3):308-312
The age assignment of cherts from ophiolitic/metamorphic complexes in northeastern Jiangxi is widely regarded as one of the crucial issues in the tectonic interpretation of South China. The ophiolitic and metamorphic complexes in northeastern Jiangxi have been traditionally regarded as part of the Proterozoic “Banxi (=Penhsi) Group” of the Jiangnan Uplift. However, recent reports of Late Paleozoic radiolarians from the rock complexes have caused some researchers to question the traditional interpretation of the tectonic and paleogeographic framework in the region; but other workers are suspicious about these findings. In order to test the validity of the putative radiolarians, we, an interdisciplinary study group including micropaleontologists, tectonic specialists and regional geologists, conducted field investigations and multiple re-samplings of the localities where the reported fossils were collected. Our comprehensive study shows that the chert of the ophiolitic complex and the associated low-grade metamorphic slate yield Mesoproterozoic and Neoproterozoic acritarchs, confirming the traditional view of their age assignment (Proterozoic); on the other hand, no recognizable radiolarian fossils have been discovered therein, thus raising questions about the recently published result of Paleozoic radiolarian findings. Probable causes for the putative radiolarian findings are thus discussed herein. Geochemical characteristics indicate that the chert sedimentation most probably occurred under a continental margin setting. 相似文献
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中国西藏南部喜马拉雅相的乐平统 总被引:3,自引:0,他引:3
西藏南部二叠系色龙群,曲布日嘎组等“喜马拉雅相”地层产有冈瓦纳区系的以Siriferella rajah,Taeniothaerus densipustulatus,Neospirifer(Neospirifer)kubeiensis和Retimarginifera xizangensis为典型代表的腕足动物群。其组成和演进层序与属于冈瓦纳大陆北缘的巴基斯坦盐岭的Wargal组上部和Chhidru组,克什米尔的Zewan组,印度斯匹提Kuling页岩上部的Gngrei组,尼泊尔西北部的Senja组和澳大利亚西部Hardman组的很接近;时代曾被归入瓜达鲁普世或乐平世早期等,分歧较大。近年来在盐岭等地发现这一冈瓦纳区系动物群明显高于乐平世一部牙形类Clarkina dukouensis带,并与菊石Cyclolbus和有孔虫Claniella动物群共生。由此推定整个色龙群或曲布组和曲布日嘎组都应属于乐平统,它与上覆三叠系以牙形类化石Hindeodus parvus和菊石Otoceras出现为界,代表冈瓦纳大陆北缘乐平世沉积的一个三级地层层序。层序以海进初期沉积的低水位体系域的曲布组石英砂岩为标志,其顶界则为比二叠系-三叠系界线略低的一个快速海进面。 相似文献