共查询到19条相似文献,搜索用时 55 毫秒
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本研究报道了1件产自辽西建昌要路沟义县组的齿槽鸟化石,明确了该属种的产地和地层信息。新标本展示了齿槽鸟独特的牙齿特征,即牙齿舌侧面发育沟槽,支持这一特征的稳定性。同时,新标本补充了一些齿列、胸骨和腰带等重要信息,比如:前颌齿4颗,上颌齿4颗,下颌齿7颗;胸骨前缘弧形,中部发育小的胸骨柄,侧后缘发育凹缺和突起,后外侧突的末端呈三角形;髂骨背缘较平直,中部发育一个瘤状突起,腹前缘发育前臼窝;耻骨脚末端变尖,略前弯;坐骨侧面发育一纵脊,远端背缘发育一沟槽。这一发现丰富了对齿槽鸟的时代分布和骨骼形态学认识。 相似文献
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矢部龙(Yabeinosaurus)是早白垩世热河生物群中发现的第一个蜥蜴类群.近年来发现了数量丰富的矢部龙化石,使得深入了解该属头骨形态的种内、种间分异成为可能.本研究借助CT扫描和三维重建技术,描述了一件近完整的大型成体矢部龙骨架化石.该标本展示了一些新的形态学信息,比如,三角形的下颌隅骨突、外上髁孔、尾自切和再生... 相似文献
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本研究描述了一件产自辽西建昌九佛堂组的甲龙类化石,代表这一地区的首次记录。化石为一幼年个体骨架,体长约300 mm,以前颌齿发育、下颌关节窝低于齿列、末端尾椎前关节突拉长、指/趾爪背视呈三角形等为特征。依据这些特征,将其归入辽宁龙。辽宁龙化石大量发现于义县和凌源等地区的义县组,之前仅有一例九佛堂组的化石报道。本次发现进一步表明辽宁龙在辽西地区可能具有更为广泛的古地理分布和时代延续。同时,辽宁龙成体化石的缺失和幼体化石的大量发现,暗示了以森林-湖泊为主的热河生态系统或许更适于幼年甲龙的生存。 相似文献
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辽西建平县义县组火山岩形成构造环境的地球化学鉴别 总被引:1,自引:0,他引:1
对辽西建平县平庄-马厂盆地的火山岩进行了岩石学、地球化学、同位素年代学研究.结果表明,火山岩属白垩纪.义县组火山作用可分为2个亚旋回.火山岩主要为流纹岩类、粗面岩类和粗安岩类.义县旋回火山岩属高钾钙碱性岩石系列.火山岩具有高SiO2,Al2O3,K2O,Na2O和低MgO,TiO2的特征.火山岩富集大离子亲石元素(LILE)K,Rb,Sr,Zr,Ba,Pb,Li等,高场强元素(HFSE)Nb,Ti,P及相容元素Co,Ni,Cr,V亏损.火山岩为轻稀土富集型,总体显示弱负铕异常、无铈异常.对火山岩形成的构造环境的地球化学判别,表明义县组火山岩成岩物质主要来源于下地壳的部分熔融,岩浆在上升过程中受到了一定程度的上地壳物质的混染.火山岩形成于板内岩石圈不均匀伸展作用环境,具有大陆板内造山带火山岩的基本特征. 相似文献
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东营凹陷沙三下亚段油页岩中古湖泊学信息 总被引:29,自引:0,他引:29
通过沉积学、矿物学、地球化学以及数学模拟计算表明,沙三下亚段油页岩纹泥状的律层段形成于具有明显分层的较深湖区,是湖盘内部水体的生物与化学环境对季节性气候变动的直接响应,其中夏季环境效应起着关键性的作用.总的来说,当时湖底是处于严重缺氧的环境,有利于油气的生成与保存,但显微生物扰动构造以及事件性细层的发现说明这种严重缺氧环境并不十分稳定,常遭周期性充氧事件的干扰.虽然湖水分层毋庸置疑,但是否达到盐度明显分层的程度,或是否属温度/盐度混合分层目前尚难定论. 相似文献
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苏皖地区下二叠统孤峰组4条剖面中含有极其丰富的放射虫化石,经鉴定计9属27种,它们主要由阿尔拜虫类albillellids,球形多囊虫类spherical polycystine和十字多囊虫类stauraxon polycystine组成,并且可以划分成3个组合带,即Pseudoalbaillella fusiformis-P.longtanensis,Follicucullus monacant 相似文献
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为了明确鄂尔多斯盆地中东部中侏罗统延安组沉积时期的古环境特征,利用泥岩样品进行微量元素和稀土元素等分析测试,对测试结果进行统计分析,结合古植物和孢粉组合等特征,对盆地中东部延安期的古环境进行恢复重建。结果表明:锶、硼、相当硼、镓、锂、镍、Sr/Ba、B/Ga、Rb/K2O和Th/U的数值说明延安期水体主体为淡水-半咸水环境;Fe2+/Fe3+、Ni/Co、V/Cr、V/(V+Ni)、U/Th、δU和Cu/Zn的数值反映延安期主要存在弱还原弱氧化-氧化的沉积条件;通过对比延安组和直罗组Sr/Cu、Mg/Ca、Rb/Sr、FeO/MnO、Al2O3/MgO和Sr/Ba的数值,结合古植物和孢粉组合特征,认为从早侏罗世富县期到中侏罗世延安期,再到中侏罗世直罗期,鄂尔多斯盆地中东部经历了炎热半干旱半湿润—温暖湿润—炎热半干旱半湿润的气候变化过程。研究成果对于恢复中侏罗世延安期盆地沉积格局、重建古地理及成藏研究具有重要意义。 相似文献
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白垩纪是典型的温室气候时期,对白垩纪陆相系统古环境和古气候的研究有助于对现今升温的地球上陆相气候系统未来气候变化做出更好的预测.松辽盆地是我国大型陆相白垩纪沉积盆地,保存了近乎完整的白垩纪陆相沉积记录.晚白垩世嫩江组二段的黑色页岩是松辽盆地重要的烃源岩,并记录了湖泊缺氧事件、海侵事件和白垩纪超静磁期结束等重大地质事件.... 相似文献
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A new iguanodontid,Jinzhousaurus yangi gen. et sp. nov., is erected based on the cranial and dental morphology of a specimen from the Yixian Formation of western
Liaoning. Although a few primitive characteristics remain,Jinzhousaurus yangi display a number of characteristics similar to those seen in derived iguanodontids. Other interesting characteristics include
the absence of antorbital fenestra and the frontal excluded from the participation in orbit, which are closer to the condition
in hadrosaurids. The unusual combination of the characteristics provides important data for assessing morphological evolution
toward hadrosaurs. The new discovery also represents the first reported large-sized dinosaur from Jehol fauna in western Liaoning,
and increases the diversity of this famous fauna. Furthermore, the discovery of a derived iguanodontid from the Yixian Formation
provides further evidence supporting a Cretaceous age of the Jehol fauna, which is consistent with an isotopic age. 相似文献
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This is the first reports of a few fossil monocotyledons, includingLiaoxia chenii gen. et sp. nov. (belonging to Cyperaceae),Eragrosites changii gen. et sp. nov. (Gramineae) and a monocotyledonous leaf-shoot, obtained from the Late Jurassic Yixian Formation of western
Liaoning Province, NE China. These fossils are the oldest known angiosperms in the world. It may be inferred that the earliest
angiosperms probably appeared even earlier than the Late Jurassic. 相似文献
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A multituberculate skeleton from the Lower Cretaceous Yixian Formation at Dawangzhangzi, Lingyuan City, Liaoning Province, Northeast China, provides new morphological information for early multituberculates. The specimen is the holotype of Sinobaatar lingyuanensis gen. et sp. nov. It has a narrow skull that lacks the superorbital crest or postorbital process. The dental formula is 3·?·5·2/1·0·3·2. The dental morphology, especially that of cheek teeth, of S. lingyuanensis is similar to that of Eobaatar, which places it in the family Eobaataridae. The postcranial skeleton of Sinobaatar is similar to that of other multituberculates. As in Holotheria, Metatarsal V of Sinobaatar articulates only with the cuboid and has no contact with the calcaneus, which probably represents the primitive condition of multituberculates. Nine carpals of Sinobaatar resemble those of Zhangheotherium, except the centrale being larger than the trapezoid. The dental features of Sinobaatar show again that eobaatarids are obviously intermediate between Late Jurassic multituberculates and the later forms. Because eobaatarids are only known from the Early Cretaceous, the finding of Sinobaatar, therefore, supports that the age of the Jehol Biota is most likely Early Cretaceous. 相似文献
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Discovery of a pterodactylid pterosaur from the Yixian Formation of western Liaoning, China 总被引:4,自引:0,他引:4
A well-preserved pterosaur with nearly complete skull is described from the Lower Cretaceous Yixian Formation at Sihetun in
western Liaoning. It is characterized by a low and long crestless skull, slender and pointed teeth, long metacarpal, nearly
equal length of metatarsals I–III and short pedal digit V. It is referred to a new genus and species of the family Pterodactylidae:Haopterus gracilis gen. et sp. nov. This is the first pterosaur with a nearly complete skull from the Jehol Biota; it also represents the first
non-controversial fossil record of Pterodactylidae in Asia.Haopterus is more derived thanPterodactylus from the Late Jurassic Solnhofen in Germany. This discovery extends the distribution of the family Pterodactylidae from Europe
and Africa to Asia and its latest occurrence from the Late Jurassic to the Early Cretaceous. The discovery ofHaopterus gracilis provides further evidence for the study of the origin and radiation of the Jehol Biota; it also sheds new light on the evolution
and distribution of pterosaurs in the late Mesozoic. 相似文献
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本文记述了辽宁北票义县组一件新的初鸟类(Avialae)化石,这是继中华神州鸟(Shenzhouraptor sinensis Ji et al.2002)之后初鸟类化石的又一发现。它以上颌无齿而具角质喙、胸骨发达且具龙骨突、前肢显著长于后肢等特征与始祖鸟(Archaeopteryx)不同,以后肢第Ⅰ趾爪已反转而与其它3趾对握等特征与神州鸟相区别,该化石被命名为东方吉祥鸟(新属、新种)(Jixiangornis orientalis gen.et sp.nov.)。中国辽西新近发现的中华神州鸟和东方吉祥鸟(新属、新种)目前是世界上最古老最原始真正具有角质喙和飞行能力的原始鸟类。 相似文献
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New fossil elaterid (Coleoptera: Polyphaga: Elateridae) from Yixian Formation of western Liaoning, China 总被引:4,自引:0,他引:4
A new species of the elaterid genus Cryptocoelus Dolin and Nel, 2002 from the Late Jurassic to Early Cretaceous Yixian Formation in the western Liaoning, China is described. Diagnosis of the genus is revised, and the systematic position of the genus is briefly discussed. Because the elaterids originated in the Early to Mid-Jurassic, this new material from the Late Jurassic-Early Cretaceous will enhance our understanding of the transition between ancient elaterids and extant ones, bridge the gap of cryptic relationships between the Mesozoic cupedids and elaterids, and expand our knowledge of their evolutionary history. 相似文献
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A new species of the elaterid genus Cryptocoelus Dolin and Nel, 2002 from the Late Jurassic to Early Cretaceous Yixian Formation in the western Liaoning, China is described. Diagnosis of the genus is revised, and the systematic position of the genus is briefly discussed. Because the elaterids originated in the Early to Mid-Jurassic, this new material from the Late Jurassic-Early Cretaceous will enhance our understanding of the transition between ancient elaterids and extant ones, bridge the gap of cryptic relationships between the Mesozoic cupedids and elaterids, and expand our knowledge of their evolutionary history. 相似文献
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Four new fossil species of the family Ommatidae from the Yixian Formation of western Liaoning,China are described. Two of them belong to tribe Brochocoleini:Brochocoleus sulcatus sp.nov.and Brochocoleus angustus sp.nov.The other two refer to tribe Ommatini:Cionocoleus planiusculus sp.nov.and Cionocoleus cervicalis sp.nov.The diagnosis of Brochocoleus and Cionocoleus, respectively,are revised.A preliminary analysis of geographical distribution suggests a possible migration pathway of the genus Bro- chocoleus.The relationship between the genus Cionocoleus and the extant family Crowsoniellidae is briefly discussed. 相似文献
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A multituberculate skeleton from the Lower Cretaceous Yixian Formation at Dawangzhangzi, Lingyuan City, Liaoning Province, Northeast China, provides new morphological information for early multituberculates. The specimen is the holotype of Sinobaatar lingyuanensis gen. et sp. nov. It has a narrow skull that lacks the superorbital crest or postorbital process. The dental formula is 3·?·5·2/1·0·3·2. The dental morphology, especially that of cheek teeth, of S. lingyuanensis is similar to that of Eobaatar, which places it in the family Eobaataridae. The postcranial skeleton of Sinobaataris similar to that of other multituberculates. As in Holotheria, Metatarsal V of Sinobaatar articulates only with the cuboid and has no contact with the calcaneus, which probably represents the primitive condition of multituberculates. Nine carpals of Sinobaatar resemble those of Zhangheotherium, except the centrale being larger than the trapezoid. The dental features of Sinobaatar show again that eobaatarids are obviously intermediate between Late Jurassic multituberculates and the later forms. Because eobaatarids are only known from the Early Cretaceous, the finding of Sinobaatar, therefore, supports that the age of the Jehol Biota is most likely Early Cretaceous. 相似文献