共查询到20条相似文献,搜索用时 15 毫秒
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Hao Lu Da-Yong Jiang Ryosuke Motani Pei-Gang Ni Zuo-Yu Sun Andrea Tintori Shi-Zhen Xiao Min Zhou Cheng Ji Wan-Lu Fu 《Palaeoworld》2018,27(1):107-116
The late Ladinian (Middle Triassic) Xingyi Fauna from the Zhuganpo Member of the Falang Formation yields abundant and well-preserved marine reptiles. Bed-by-bed excavation at Wusha in Xingyi of Guizhou Province reveals two marine vertebrate assemblages in a fossiliferous horizons that span 5.1 m in total thickness. The lower assemblage is marked by the near-shore sauropterygians, including the pachypleurosaur Keichousaurus, the nothosaurians Nothosaurus and Lariosaurus, with a strong paleobiogeographic affinity to western Tethys. The upper assemblage consists of oceanic ichthyosaurs and pistosaurs, including the large shastasaurid ichthyosaur Guizhouichthyosaurus, the euichthyosaur Qianichthyosaurus, pistosaurs Yunguisaurus and Wangosaurus, and the thalattosaur Xinpusaurus, with a closer paleobiogeographic affinity to North America. The coastal pachypleurosaur and nothosaurid sauropterygians disappeared in the upper assemblage, suggesting that they were replaced by an oceanic marine reptile community that emerged. The reptilian composition of the upper assemblage is similar to that of the Guanling Biota, which is of the Early Carnian (Late Triassic) in age and thus somewhat younger than the Xingyi Fauna. The ecological turnover of marine reptiles from near-shore to the open ocean community corresponds to the paleoenvironmental changes indicated by lithofacies analysis, δ13C and the global sea level changes. 相似文献
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OLIVIER RIEPPEL FMLS 《Zoological Journal of the Linnean Society》2002,135(1):33-63
The jaw adductor musculature in Triassic stem-group sauropterygians is reconstructed on the basis of a paradigmatic model of muscle architecture (functional equivalence of sarcomeres) and using invariant traits of the anatomy of the trigeminal jaw adductor muscles in extant reptiles. The reconstructed jaw adductor musculature predicts trophic specializations in stem-group sauropterygians. Suction feeding is a component in prey capture for some benthic feeding, as well as for some pelagic feeding taxa. The differentiation of 'pincer' jaws is correlated with the potential for rapid, snapping bites. There is some evidence for habitat partitioning among Triassic stem-group sauropterygians with respect to trophic specialization. © 2002 The Linnean Society of London. Zoological Journal of the Linnean Society , 2002, 135 , 33–63. 相似文献
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Preparation of the holotype specimen of Bobosaurus forojuliensis, a large sauropterygian from the lower Carnian of northeastern Italy, revealed new morphological data relevant in establishing its phylogenetic affinities among pistosauroid taxa and its relationships with plesiosaurians. Inclusion of B. forojuliensis in two phylogenetic analyses focusing, respectively, on sauropterygians and pistosauroids agreed in placing the Italian taxon as closer to plesiosaurians than to other pistosauroids. The phylogenetic interpretation of Bobosaurus was not biased by assumptions on character weighting, is consistent with its relatively younger age compared to most pistosauroids, extends the fossil record of the plesiosaurian basal lineage back to the Carnian and supports the earliest diversification of the clade during the Late Triassic in agreement with the record of several distinct lineages of rhomaleosaurids, plesiosauroids and pliosauroids in the lowermost Jurassic. Bobosaurus shows that the evolution of the plesiosaurian body plan from the ancestral pistosauroid grade was a step-wise process, and that some of the vertebral and appendicular specialisations of Jurassic and Cretaceous plesiosaurians had already developed in the earliest Late Triassic. 相似文献
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描述贵州兴义地区贵州龙层中新发现的鱼类4新属、4新种和一件新材料,它们是小鳞贵州鳕(新属、新种)Guizhouniscus microlepidus Liu gen.et sp.nov.,小短体鱼(新属、新种)Brachysomus minor Liu gen.et sp.nov.,秀丽兴义鱼(新属、新种)Xingyia gracilis Liu gen.et sp.nov.,臀鳞贵州真颌鱼(新属、新种)Guizhouella analilepidn Liu gen.et sp.nov,和优美贵州弓鳍鱼Guizhouamia bellula Liu et a1.,2002的一件新材料。新的发现和研究表明这是一个颇具特色的晚三叠世早期鱼群。文章还简要讨论各新属新种的系统分类位置和该鱼群在整个鱼类进化中的地位,着重论述贵州弓鳍鱼Guizhouamia的进化意义及弓鳍鱼科的系统发育问题。根据鱼群的特征贵州龙层的地质时代为晚三叠世。 相似文献
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贵州兴义中三叠世 Nothosaurus一新种 总被引:8,自引:4,他引:8
记述了贵州兴义法郎组竹竿坡段幻龙一新种———Nothosaurusyoungisp .nov .。新种以眶后弓窄 ,上颌骨和眶后骨在轭骨之后相连 ,外翼骨形成明显的腹向凸缘 ,下颌具清晰的冠状突 ,和夹板骨前端进入下颌缝合部等特征区别于幻龙的其他种。支序分析的结果表明N .youngi的原始性仅次于N .juvenilis。新种N .youngi具有Nothosaurus中的一些原始特征 ,短的下颌缝合部 ,短的上颌齿列和窄的眶后弓 ,新种在法郎组竹杆坡段的发现支持含化石地层为中三叠世拉丁期的结论。 相似文献
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粪化石是重要的遗迹化石,其内含物信息可为讨论生物行为、生理、相互关系、古环境等提供重要证据,进而对恢复和重建地质历史时期的生态系统等有重要意义。本文首次报道了贵州省兴义市泥麦古剖面中三叠世拉丁期兴义动物群化石层第35自然层的7种不同形态的粪化石。通过观察粪化石的内含物情况,发现其主要由贵州龙骨骼和鱼鳞组成,极少含有无脊椎动物碎片,表明粪化石来源于非壳食性的肉食性动物。依据粪化石的尺寸、缺少螺旋结构及相对较小的内含物碎片等信息,排除动物源是无脊椎动物、大型肉食性鱼类及大型鱼龙类的可能。结合兴义动物群下部化石组合海生爬行类实体化石的信息,进一步推断所研究粪化石的动物源应为非鱼龙的海生爬行动物,很可能是幻龙类、鸥龙类或海龙类。本文报道的7种形态的粪化石显示该下部化石层中的海生爬行动物之间至少存在1级营养等级的差异,这为恢复和重建中三叠世拉丁期海洋生态系统提供了重要依据。另外微生物的参与及泥质含量较高的厌氧环境使得该层的粪化石保存完好。 相似文献
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贵州中三叠世安顺龙(爬行纲:海龙目)一新种 总被引:6,自引:3,他引:6
中国的海龙类以前仅发现于法郎组瓦窑段,包括安顺龙和新铺龙两属。最近在法郎组竹杆坡段也发现了海龙化石(完整的骨架,中国科学院古脊椎动物与古人类研究所标本编号V 13782),被归入安顺龙属。标本产自贵州兴义乌沙,时代是中三叠世拉丁期。此标本小于黄果树安顺龙两个已知标本,但是根据以下特征判断应该是个成年个体:头骨相对较小,许多骨缝愈合,髓椎线(neurocentral suture)封闭,肱骨上各种结构已经显著分化,掌骨和跗骨骨化程度高。根据以下特征建立一新种,乌沙安顺龙(Anshunsaurus wushaensis sp.nov.):头骨相对较小(相对肩臼至髋臼长度);轭骨后突短,向后延伸不超过下颞孔之半;后背区的神经棘高度小于宽度,其背缘有垂向沟、脊;间锁骨十字形,前突基部宽;肱骨外髁沟明显,内髁很发育,在内腹侧有脊但无孔;第五掌骨比第四掌骨稍长;第四指失去一个指节;髂骨板向后背向展开;7个跗骨骨化。 相似文献
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脂蛋白脂酶(LPL)是动物脂质沉积和新陈代谢的关键酶,对生长和肉质发挥着重要作用。试验采用PCR-SSCP法和DNA直接测序技术相结合对兴义鸭L PL基因外显子8进行多态性检测,并分析其多态与生长和肉质性状的关联性。结果表明,在兴义鸭L PL基因外显子8首次检测到1个T1251C同义突变,产生三种基因型TT、TC和CC,2个等位基因T和C,基因型TT和等位基因T的频率分别为0.8077和0.8750,多态信息含量为0.1948,表现为低度多态,卡方(字2)检验表明T1251C位点的基因型分布在兴义鸭中未偏离Hardy-Weinberg平衡。最小二乘分析显示,TT基因型个体的宰前体重显著低于CC基因型(p<0.05),胸宽显著低于TC基因型(p<0.05),推测等位基因C可能是兴义鸭生长性状的有利等位基因,可作为生长性状的一个标记性辅助选择位点。 相似文献
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西北干旱荒漠区植物区系的特有现象分析 总被引:17,自引:1,他引:17
西北干旱荒漠区内中国特有属贫乏, 仅有6 属, 只占中国特有属的2.33%, 均属于新特有成分;中国特有种109 种, 隶属于49 属、18 科, 既有新特有种, 也有一些古老孑遗种;地理分布区类型, 以古地中海属和温带属占绝对优势, 均有18 属, 占总属数的36.73%;西北干旱荒漠区各地的中国特有种分别为:塔里木盆地38 种, 准噶尔盆地32 种, 河西走廊44 种, 阿拉善高原42 种, 柴达木盆地17 种。 相似文献
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Ramses Amer 《Ocean Development & International Law》2013,44(1):17-40
This article examines recent developments in the South China Sea; in particular, the China-Vietnam relationship. The developments are presented in the broader context of the Sino-Vietnamese approach to managing border disputes since full normalization of relations in late 1991. The challenges for China and Vietnam in managing their disputes and related tension in the South China Sea are also discussed. 相似文献
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Masahiro Miyoshi 《Ocean Development & International Law》2013,44(1):1-17
China's recent claims to a large “U-shaped” area in the South China Sea, involving the disputed Spratly and Paracel Islands, has given rise to a number of serious criticisms not only from neighboring states, but also some states beyond the region. The claim also raises a number of theoretical questions, including whether historic title claims without hard evidence have validity under international law. This article explores this and other issues raised by China's U-shaped claim. 相似文献
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Important events relating to the sovereignty dispute over the Spratly Islands have arisen by fits and starts since 2009, marking the start of a new phase in the legal battle over territorial and maritime claims in the South China Sea. While the exchange of legal arguments between the parties has gradually laid bare their maritime claims, much still remains shrouded in uncertainty. Among the obscure claims wanting clarification is China's infamous nine-dotted-line map, which in 2011 elicited a response and counterresponse between the Philippines and China. This article examines the maritime and territorial claims of the Philippines and China as revealed in the recent discord over the nine-dotted-line map. 相似文献
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我国东南沿海的VA菌根真菌——Ⅱ.球囊霉属四个种 总被引:3,自引:0,他引:3
从我国东南沿海广东、广西、福建、浙江、山东等省的栽培及野生植物根际分离出VA真菌球囊霉属的四个种:聚丛球囊霉Glomus aggregatum Schenck & Smith emend.Koske,微丛球囊霉G.microaggregatum Koske,Gemma & Olexia,小果球囊霉G.micrcarpum Tul.& Tul.,台湾球囊霉G.formosanum Wu & Chen。其中微丛球囊霉为我国新记录种,台湾球囊霉为我国大陆新记录种。本文除种的形态描述外,还列表介绍了其生态分布及土壤环境条件。 相似文献
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W. Huang 《Human Evolution》1989,4(1):87-92
More and more archaeological discoveries show that bifaces are not absent from China, South and East Asia. Bifaces played
a very important role in early Paleolithic industries here. The tool assemblage of this industry is similar to those of biface
cultures in Africa and Europe. These discoveries will increasingly fill and level up the ≪gap≫ between the cultures of the
East and West. 相似文献
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口蹄疫病毒China/99基因组RNA序列测定及比较分析 总被引:7,自引:0,他引:7
测定了1999年我国口蹄疫流行毒株(China/99, Tibet)基因组全序列, China/99基因组RNA全长8173个核苷酸(nt), 开放阅读框含盖6999 nt, 编码2332个氨基酸的聚合蛋白. 5′和3′非翻译区(UTR)分别长1081和93 nt. China/99与12株参考株基因组序列比较发现: China/99与英国2001年流行毒、海南和西藏1999年流行毒1d基因的序列同源性高达97%以上, 均属泛亚毒株; 在牛和猪FMDV的功能未知区、p2和p3区存在较为显著的核苷酸序列差异, 3a基因最为显著; l, 1a, 1b, 2a, 2c, 3b和3d基因没有核苷酸缺失或插入现象, 属于病毒必需基因; 口蹄疫病毒S片段、功能未知区和内部核糖体进入位点(IRES)二级结构均可分为3种类型. S片段和3′UTR折叠成一个三叶草类似结构. 相似文献
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为配合《中国藻类志》的编写,1982—1987年,作者先后到过安徽的36个县(市)和地区,共采集藻类标本约1000号,已鉴定出属于绿球藻目的植物150余种。本文报告的11种及1变种,均为我国首次记录,它们分别隶属于纤维藻属(Ankistrodesmus),小椿藻属(Characium),胶网藻属(Dictyosphaerium),霍氏藻属(Hofmania), 相似文献