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1.
辽宁北票地区义县组地层划分与对比   总被引:2,自引:0,他引:2  
辽宁北票地区义县组是一套中生代陆相火山-沉积岩系,主要由中-基性火山熔岩、火山碎屑岩及陆相沉积岩构成.依据火山活动的规律性,将本区义县组划分为4个岩性段,自下而上分别为:一段:底砾岩、基性-中基性火山岩段;二段:湖相沉积(或称珍稀化石层)岩段;三段:基性火山岩段;四段:砾岩段.其中,义县组一段产丰富的以鹦鹉嘴龙为主的古脊椎动物化石.二段产大量热河生物群化石,包括著名的中华龙鸟、孔子鸟和辽宁古果等珍稀化石,是义县组最重要的化石产出层位.从西向东,义县期火山活动具明显的由早到晚、由基性-中性-酸性(偏碱性)的演化特征.  相似文献   

2.
报导辽宁北票下白垩统义县组尖山沟层松柏类金钱松属一新种Pseudolarix gaoi sp. nov. 和一个新联合种Pseudolarix chilitica (Sun et Zheng) Zheng, comb. nov.,前者是一个保存较好的带叶小枝,具长枝和短枝,长枝又可分为主枝和侧枝, 侧枝长短不一,其上着生有许多呈螺旋状排列的桶状短枝;叶在短枝上簇生,线形或披针状线形,扁平,上表面中脉不隆起,下表面沿隆起的中脉有两条气孔带;气孔为单唇式,极副卫细胞为伸长的长方形.后者是以分散保存的Schizolepis式的雌球果和果鳞、Pityospermum 式的翅籽、着生于短枝末端上的雄球果以及 Pityocladus 式的带叶小枝为代表.上述两种松柏类化石可能代表仅幸存于中国南方现生金钱松属单型种Pseudolarix amabilis (Nelson) Rehd. 的先驱分子.有一部分Schizolepis式的雌球果可能与金钱松属的起源与演化有关.  相似文献   

3.
邵济安  杨蔚 《地质学报》2011,85(3):379-382
本文针对"辽宁北票兴隆沟火山岩的野外产状、岩石成因及地质意义"一文对笔者的质疑,阐述了对北票下侏罗统兴隆沟组开展地质调查的经过.结合质疑的问题,从野外地质观察和同位素年代学两个方面展开讨论,并且根据新获得的火山岩202Ma的Ar-Ar年龄,重申辽西北票兴隆沟组的时代属于早侏罗世的结论.  相似文献   

4.
Three new genera and species Archaeoperla rarissimus gen. et sp. nov. (Perlidae), Liaotaenionema tenuitibia gen. et sp. nov. (Taeniopterygidae) and Parvinemoura parvus gen. et sp. nov. (?Nemouridae) are described and illustrated. All of them were collected from Yixian Formation of the western Liaoning, China. Hitherto, A. rarissimus is the oldest species possessing typical characters of Perlidae; the finding of L. tenuitibia indicates taeniopterygids once lived in the northeastern China in the late Mesozoic, but frequent volcanic activities, climate changes, or other environmental changes might have resulted in the disappearance of Taeniopterygidae in northern China after Mesozoic. Ancestral groups of Nemouridae have been abundant from Middle Jurassic, and male genitalia of P. parvus gen. et sp. nov. has been developed and similar to extant Nemouridae in the late Mesozoic. The stonefly fossils found from Yixian Formation are not divers at the species level, but rich at the family level. The diversity of stonefly implies different microclimate existed in the northeastern China at that time. A large old lacustrine basin existed in the western Liaoning, surrounded by hygrophilous plants on swampland and lake shore, warm and humid; tall arbor and boscage on the hillside nearby, mild and dry; mountains in the distance, rivulets running among the mountains, cool and wet. Many insects, prefer cool climate (e.g. stonefly, raphidiopterans, et ai.), lived in the mountains with rivulets.  相似文献   

5.
根据新材料,对始无齿翼龙的特征进行了修订:中部颈椎体没有神经棘;肱骨三角嵴的长度与肱骨长度之比率约为0.2.5:翼掌骨的长度与第二翼指骨的长度几乎相等;第二翼指骨与第一翼指骨的长度之比率约为0.76。始无齿翼龙的新标本与正型稍微不同,可能由个体发育所引起。  相似文献   

6.
辽西北票地区义县组古气候环境标志及其意义   总被引:10,自引:2,他引:10  
野外地质调查及综合研究表明,包含中华龙鸟、被子植物等珍稀化石的热河生物群的主要赋存层位为义县组二段湖相沉积岩层。对产于不同地点沉积层中的植物、孢粉化石以及木化石进行了总结研究,分析了它们所反映的古气候环境,认为义县组沉积时期存在大量的喜温湿植物,总体指示温暖湿润的生存环境。同时,一些旱生的买麻藤类植物的普遍存在、本内苏铁类的膜质叶以及松柏类的鳞状叶等的特征反映了存在季节性干旱、半干旱气候的可能性。这种气候状况的出现可能与火山活动有关。  相似文献   

7.
初步研究了辽西地区热河生物群的一具近完整的蜥脚类恐龙骨架,其代表了一新的巨龙型类恐龙——中国辽宁巨龙(Liaoningotitan sinensis gen.et sp.nov)。其主要特征为:上颌骨腹缘下凸,上颌齿列短且位于前部;颧骨前端近平齐于眶前窗的前缘;翼骨的方骨支基部收缩;上颌齿呈叠瓦状排列;上颌齿冠窄勺形,切面呈D字形,缺失唇侧沟和小锯齿;下颌齿9枚,明显小于上颌齿,排列稀松;下颌齿冠不对称,切面呈椭圆形,舌侧的沟和嵴发育,齿冠基部向舌侧膨大;肱骨近端扩展,约为长度的54.9%;肠骨前髋臼突前端较尖。初步的支序分析显示,辽宁巨龙属于巨龙型类恐龙,是比盘足龙和梁龙更为进步的类群。  相似文献   

8.
关于辽西北票地区兴隆沟组火山岩时代的再认识   总被引:1,自引:0,他引:1  
邵济安  杨蔚 《地质通报》2008,27(6):912-916
针对近年来关于兴隆沟组火山岩同位素年龄及地层归属方面存在的分歧,通过详细的地质填图已查清,近年报道的2组U-Pb同位素年龄均为贯穿兴隆沟组火山-沉积地层的霏细斑岩脉年龄,兴隆沟组地层仍应归属为下侏罗统.  相似文献   

9.
辽西义县组奔龙类化石一新种   总被引:5,自引:1,他引:4  
在辽宁西部义县头台的义县组中新发现的1件奔龙类化石标本,显示出许多中国鸟龙属(Sinornithosaurus)所具有的特征,如上颌骨眶前窝侧面具有装饰性凹坑、前颌骨齿无边缘小锯齿、齿骨后缘二分叉、指节Ⅲ-1略长于指节Ⅲ-2的2倍、?骨Ⅲ部分窄?型形态等。但其头骨的部分骨骼与千禧中国鸟龙(S.millenii)有明显的区别前颌骨主体部分相对较高,其长仅稍大于其高,前颌骨角大,前颌骨上颌突与鼻突均很长,上颌骨不参与外鼻孔的构成,上颌骨窗相对较小且为圆形,方颧骨上升突明显长于颧骨突,齿骨长高之比小等。此外,新标本肠骨的耻骨柄前后方向的宽度小于髋臼宽度。这些不同之处表明,义县头台的标本应为中国鸟龙属另一新种,将其命名为郝氏中国鸟龙(新种)(S.haoianasp.nov.)。  相似文献   

10.
辽西早白垩世九佛堂组一新的初鸟类   总被引:3,自引:0,他引:3  
高春玲  刘金远 《世界地质》2005,24(4):313-318
描述了产于辽宁朝阳盆地联合乡回家子南山早白垩世九佛堂组一新的初鸟类化石。因其头骨下颌近前部具有一嵴状突;前肢短于后肢,前后肢长度比率为0,82;掌骨未愈合;后足纤细,第一趾反转,与其他三趾对握;尾椎少于23节等特征,区别于其他任何已知的初鸟类,故命名为一新属、新种一粗颌大连乌(Dalianraptor cuhe gen.et sp.nov)。  相似文献   

11.
A New Ornithocheirid from the Early Cretaceous of Liaoning Province, China   总被引:5,自引:0,他引:5  
Based on a nearly complete skeleton with skull from the Early Cretaceous of Liaoning Province, a new ornithocheirid pterosaur: Boreopterus cuiae gen. et sp. nov. is erected. Boreopterus cuiae is different from other pterosaurs preserved with skulls known from the western Liaoning Province and its neighboring areas. Tiffs new oterosaur has more and larger teeth than those in other ornithocheirids. Its anterior nine pairs of teeth are larger than other teeth. The fourth pair of upper and lower teeth are slightly larger than the third pair. Overall, Boreopterus cuiae shows much small range of tooth size variation than Anhanguerapiscator and Coloborhynchus robustus. The new taxon shares with other ornithocherids in having a relatively large size of the third and fourth pairs of teeth.  相似文献   

12.
Discovery of a New Pterosaur in Western Liaoning,China   总被引:2,自引:0,他引:2  
The pterosaur from the Yixian Formation in Beipiao, Liaoning Province, ischaracterized by the medium-sized individual, short tail, presence of the gastralia, strongforelimbs, radius and ulna longer than wing-metacarpal, extremely narrow and elongatemetatarsals, degenerated and small phalanx V of hindlimb and so on. It must be a new genusand species, Eosipterus yangi gen. et sp. nov., in the early groups of the SuborderPterodactyloidea. This is the first record of pterosaurs found in Liaoning Province. The fossilprovides new evidence for further determining the nature and geological time of the JeholFauna and for studying the palaeogeography and palaeoenvironment.  相似文献   

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