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1.
Dongbeititan dongi, the first sauropod dinosaur from the Lower Cretaceous Jehol Group of western Liaoning Province, China 
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下载免费PDF全文 WANG Xuri YOU Hailu MENG Qingjin GAO Chunling CHENG Xiaodong LIU Jinyuan 《《地质学报》英文版》2007,81(6):911-916
We herein describe a partial postcranial skeleton of a sauropod dinosaur recovered from the Lower Cretaceous Jehol Group in the Beipiao area of western Liaoning Province, northeastern China. A suite of features it possesses, including the camellate internal structure of its presacral elements, the existence of pneumatocoels on the proximal ends of the dorsal ribs, and especially the medially deflected proximal portion of the femur, definitively establish the titanosauriform affinities of the specimen. It differs from other titanosauriforms in having a craniocaudally elongate coracoid with a squared cranioventral extreme and a long, smooth, and slightly convex acetabular edge of the pubis. It represents a new taxon, Dongbeititan dongi gen. et sp. nov. Comparative studies suggest that Dongbeititan is a basal titanosauriform, more derived than Euhelopus, Fusuisaurus, and Huanghetitan, but less derived than Gobititan and Jiutaisaurus. Dongbeititan represents the first sauropod dinosaur reported from the Lower Cretaceous Jehol Group of western Liaoning Province. 相似文献
2.
A new titanosauriform sauropod Dongyangosaurus sinensis gen. et sp. nov. from the early Late Cretaceous of Dongyang County, Zhejiang Province, is erected based on a partial postcranial skeleton. It is characterized by complex laminae on the lateral surface of the neural spines and postzygapophyses of dorsal vertebrae, a distinct fossa on the ventral surfaces of the prezygapophyses of dorsal vertebrae, distinct fossae are also present on the lateral surface of the postzygapophysis of anterior caudal vertebrae; pubis is shorter than ischium, the small obturator foramen of pubis elongated, and nearly closed. The lamina complexity of dorsal vertebrae in Dongyangosaurus indicates that a higher diversity of titanosauriformes occurred during the early Late Cretaceous in China. 相似文献
3.
大型复杂采空区由于具有分布范围广、多层、厚度及埋深不等和周围岩性复杂等特点,导致其注浆质量检测难度较大,目前尚无可靠的系统检测方法。结合某采空区注浆工程实践,对浆液结石体的电阻率进行了现场试验,得到了浆液结石体的视电阻率范围为93～130m,与采空区及围岩均有较大差异。运用电测深法和电磁波CT对采空区注浆前后进行检测,发现注浆后浅部0～30m范围内,视电阻率普遍得到降低且变得相对均匀稳定; 深部低阻异常在注浆后电阻率也得以减弱,且均匀范围明显扩大; 电磁波吸收系数在40～70m范围内得到提高约25%。钻探取心发现,多数孔内可见注浆结石体; 检测孔的后期注浆中, 10个孔的注浆量均不大于周围相邻4个孔的注浆量平均值的15%。对以上检测结果分析可知:采空区在物性特征上表现为较低的电磁波吸收系数,注浆以后升高; 地下水位之上的采空区表现为较高的电阻率,注浆之后降低,地下水位以下的采空区则反之。注浆前后采空区物探差异明显,本段落采空层的浆液充填效果较好,几种检测方法的结果具有良好的对应关系。同时表明,采用全域检测的电测深和局部详查的电磁波CT相结合的物探方法,与钻探取心结果及检测孔后期注浆数据进行分析对比,可以对大型复杂采空区注浆效果进行有效检测和评价,可为类似采空区提供借鉴。 相似文献
4.
The Early Cretaceous Zhidan Group in the northern Ordos Basin, Inner Mongolia, yielded a large number of tetrapods, including turtles, choristoderes, crocodyliforms, psittacosaurs, stegosaurs, theropods and birds. Well-preserved sauropod teeth have been found in the Luohandong Formation, a middle-upper unit of the Zhidan Group. The large V-shaped wear facet, low slenderness index value, labial grooves, lingual ridge and concavity on the tooth crown suggest that these teeth are from titanosauriforms. Moreover, the presence of the prominent bosses on the lingual side of the tooth crown indicates these teeth should be identified as Euhelopus teeth further. The existence of Euhelopus in Ordos Basin (Inner Mongolia), Shandong Province and western Liaoning Province shows some connections about vertebrate faunas during Early Cretaceous in these areas. Other tetrapod groups such as turtles (Sinemys, Ordosemys), choristoderes (Ikechosaurus), psittacosaurs (Psittacosaurus) and birds (Cathayornis) provide more evidences for this viewpoint. 相似文献
5.
本文描述了产自中国辽宁省北票市早白垩世义县组一新的伤齿龙类化石——柯氏辽宁猎龙(Liaoningvenator curriei gen. et sp. nov.)。它具有伤齿龙类以下特征: 数量众多且密集的上颌齿与下颌齿; 牙齿的齿冠与齿根之间显著收缩; 齿骨侧表面具有一沟, 营养孔位于该沟内; 远端尾椎背部的神经棘减弱为一个沟。它不同于其它伤齿龙类的特征主要为坐骨靴大, 侧面观近乎三角形, 坐骨闭孔突细长; 尾椎形态转变点位于第7尾椎。系统发育分析表明柯氏辽宁猎龙与短羽始中国羽龙(Eosinopteryx brevipenna)构成姊妹群, 位于同一分支内。它们具有如下共同特征: (1)上颌骨和下颌骨前面部分的牙齿前隆无锯齿; (2)颈肋较其相关节的椎体长; (3)肠骨前缘直。辽宁猎龙代表了辽西同等层位发现的第5个伤齿龙类。骨组织研究显示辽宁猎龙的骨骼已接近成熟, 死亡时至少4岁。它为该地区的基干伤齿龙类恐龙提供了新的解剖学信息, 并丰富了目前中国已知早白垩世伤齿龙类的多样性。 相似文献
6.
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
7.
Based on the systematic study of two fossil skeleton specimens collected from the top of the third member of the marine Lower Triassic Jialingjiang Formation of Yuanan, Hubei Province, South China, a new Early Triassic primitive ichthyosaur Chaohusaurus zhangjiawanensis sp. nov. is reported and described. The beds yielding the type material are correlated with the Neospathodus homeri-N. triangularis Conodont zone. The new taxon is most similar to Chaohusaurus geishanensis Young and Dong, 1972 in the shape and configuration of the scapula, forefin, pelvic girdle and hindfin, presacral vertebral count and well-developed caudal peak, but distinguished from the latter by its larger size, the position of the pineal foramen in the centre of the parietal, the occurrence of a larger calcaneum in hindfin and the first sacral rib with distal expansion. The new species exhibits common features of primitive ichthyosaurs such as: (1) the prefrontal has an antero-dorsal shelf projecting towards the orbit; (2) the upper temporal fenestra is small; (3) the postorbital and the squamosal meet laterally to the upper temporal fenestra; and (4) cylindrical centra. However, more derived ichthyosaur characters are seen with the frontal separated from the orbital dorsal margin by the contact of the prefrontal and postfrontal, which offer new clues to the early radiation of ichthyosaurs. 相似文献
8.
The upper Campanian-lower Maastrichtian site of Lo Hueco (Cuenca, Spain) has provided a set of well-preserved partial skeletons in anatomical connection or with a low dispersion of their skeletal elements. One partial skeleton is herein described and a new titanosaurian sauropod is established, Lohuecotitan pandafilandi. This titanosaur is diagnosed by eight autapomorphic features: dorsally and ventrally widened or bifurcated posterior centrodiapophyseal lamina in anterior and middle dorsal vertebrae; short postspinal lamina with a transversely expanded distal end represented by smooth scars in the dorsal vertebrae; anteriormost caudals with the medial spinoprezygapophyseal and medial spinopostzygapophyseal laminae ventrally connected with the prespinal and postspinal laminae, respectively; anterior caudal neural spines with a dorsal projection of the prespinal and postspinal laminae; anterior caudal neural spines bears a “greek-cross”-like cross-section; middle caudal centra having two round and rough structures in the dorsal edge of the posterior articulation, which extends to the dorsal surface of the centrum; the articular ends of the rami of the haemal arches are divided in two articular surfaces; and tuberosity between the anterior and the lateral trochanter of the fibula. The herein performed phylogenetic analysis considered L. pandafilandi as a member of Lithostrotia more derived than Malawisaurus. The known palaeodiversity of the Late Cretaceous Ibero-Armorican titanosaurs is increasing, and further analyses focused on this group will be necessary to better understand the evolutionary history of European titanosaurs and to clarify their relationships within Titanosauria. 相似文献
9.
Ping Xu 《Geotechnical and Geological Engineering》2014,32(2):403-410
The conformal mapping method of complex functions and expansion method of wave functions are adopted, the stresses and displacements at the boundary between the cavities and inner fluids are considered as continuous, and then the theoretical solutions are obtained about the scattering problems of incident P waves by several fluid-filled cavities. Two circular cavities are taken as examples, the influences of frequencies of incident P waves, whether there are inner fluids or not and the spacing distances between the two cavities on the scattering amplitudes are studied, and the results reveal that: the scattering amplitudes of two cavities decrease when the distance between the two cavities increase and they reach constants when the spacing distance exceeds 7.5 times of cavities radius, and the inner fluids would absorb part of energy of the scattered waves and the scattering amplitude of the cavities filled with fluids would slightly smaller than those without fluids. 相似文献
10.
The Late Cretaceous (Santonian) continental vertebrate locality of Iharkút, western Hungary has provided numerous azhdarchid pterosaur remains including the recently described, Bakonydraco galaczi. Since the first report of these fossils, additional remains have been discovered that improve considerably our knowledge of some aspects of the anatomy of azhdarchid pterosaurs. New cranial material described here indicates an edentulous, non-crested premaxillary rostrum in Bakonydraco similar to that of Quetzalcoatlus and reveals that this rostrum was considerably thinner and more lightly built than the relatively massive, pointed mandibular symphysis. In addition, the contact surface of the upper and lower jaws of Bakonydraco at least in the symphyseal region was more similar to Tapejara wellnhoferi than to other azdarchids: the contact is irregular and the premaxilla does not fit closely the rostral part of the mandible. Among the postcranial material the atlas-axis complex possessing lateral pneumatic foramina is of great importance because it further supports the notion of interspecific variability of vertebral pneumaticity among pterosaurs. 相似文献
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12.
This paper proposes an interpolation method based on a modified Kohonen artificial neural network, and is used to interpolate
marine gravity data on a regular grid. This method combines accuracy comparable to that of kriging with a much shorter computing
time than kriging. It is particularly efficient when both the size of the grid and the quantity of available data are large.
Under some hypotheses similar to those of kriging with a trend, the unbiasedness and optimality of the method can be demonstrated.
Comparison with kriging with a trend using marine gravity data shows similar results. Although neural interpolation is slightly
less efficient, it is more robust outside of the marine data area. 相似文献
13.
Lirainosaurus astibiae was originally described by Sanz and collaborators in 1999 on the basis of a skull fragment, isolated teeth, several vertebrae (e.g. the holotypic anterior caudal vertebra) and appendicular bones from the Late Cretaceous of Laño (northern Spain). A review of all the vertebral remains, including new material (cervical, dorsal and caudal vertebrae, dorsal ribs, haemal arch), provides additional information about the axial skeleton of Lirainosaurus. A study of the laminae and fossae shows interesting variations in these structures in the axial series, especially concerning the prezygapophyses and diapophyses: e.g. the X-shaped morphology of the centroprezygapophyseal lamina only in the posterior dorsal vertebrae, and the division of the postzygodiapophyseal fossa into two fossae in the posterior dorsal vertebrae and the proximal caudal vertebrae. Two vertebral characters are here considered to be autapomorphic for L. astibiae: the presence of a lamina in the interzygapophyseal fossa in the most proximal caudal vertebrae (a postzygodiapophyseal lamina that separates the ventral postzygapophyseal centrodiapophyseal fossa and the dorsal postzygapophyseal spinodiapophyseal fossa), and the spinopostzygapophyseal structure not posteriorly projected in the posterior caudal vertebrae. The combination of characters present in the axial remains of Lirainosaurus astibiae supports the idea that it is a derived lithostrotian close to Saltasaurinae. 相似文献
14.
塔河油田下奥陶统碳酸盐岩储层测井分类识别研究 总被引：1，自引：0，他引：1
塔河油田下奥陶统碳酸盐岩为一套缝洞发育的复杂储层,通过大量已知井的测井曲线与岩心分析数据对照观察、分析,归纳出了五种储层的电性分类识别标准。在此基础上,又利用自然伽玛(GR)、深浅侧向电阻率(Rd,Rs)、声波时差(AC)、密度(DEN)、中子孔隙度(CNL)的响应特征,建立了神经网络识别模型。通过在该区三十多口井的实际应用,取得了较好的效果。 相似文献
15.
Christoph Spötl Yuri Dublyansky Michael Meyer Augusto Mangini 《International Journal of Earth Sciences》2009,98(3):665-676
The area south of the prominent east–west trending Salzach Valley at the northern rim of the Central Alps of Austria has long
been known to host anomalously warm springs emerging from a highly deformed calcite marble (Klammkalk). This unit also hosts
cavities whose shapes suggest a hydrothermal karst origin and which are lined by calcite spar. We report here petrographic
and isotopic evidence suggesting that dissolution by ascending low-temperature thermal waters also played an important role
in the origin of a large cave in this region, Entrische Kirche. A paleo cave wall, preserved behind a thick flowstone in the
interior of this cave, revealed a brownish bleaching zone which contrasts to the medium grey colour of the unaltered marble
beneath. Across this zone the C and O isotope values gradually decrease by 3 and 11‰, respectively. These compositions are
very different from those of the speleothem above but are similar to phreatic calcite spar from hydrothermal karst cavities
in other outcrops in the area, where the absence of two-phase fluid inclusions suggests a low-temperature (less than ca. 50°C)
hydrothermal origin. U/Th dating of the flowstone capping the alteration zone yielded a minimum age of the thermal water invasion
in Entrische Kirche of ca. 240 kyr. There is no evidence in Entrische Kirche that these palaeowaters reached the point of
calcite precipitation, but it is physically conceivable that higher and as yet unexplored parts of this deep (ca. 900 m) cave
contain cavities lined by phreatic cave spar. 相似文献
16.
Current views on the internal structure of many glacial landforms need further definition. For example, drumlinized Halton till plain near the Scarborough Bluffs, Ontario would traditionally be. viewed as a lodgement till sheet, but it was found to consist of complex sedimentary assemblages including sediment flows, melt-out, deformation and lodgement tills. These facies vary spatially depending on whether deposition occurred beneath grounded ice or within subglacial cavities. Proglacial sediments bury portions of the till plain. Surface Rutings and drumlins clearly indicate the action of subglacial processes on the surface of Halton drift. Sedimentary structures at the contact between stratified sediments and diamictons within the Late Wisconsinan Halton drift are similar to those in older beds exposed at Scarborough Bluffs. The demonstration of the role of grounded ice in Halton drift and the similarity of sedimentary structures to those of the underlying Thorncliffe and Sunnybrook sediments suggests that the action of grounded ice cannot be ruled out in the case of the lower beds, as has been done by Eyles & Eyles ( Geology 11 , 146–152, 1983). Thus, surface Halton drift may be a model for recognition of similar environments of deposition in older beds beneath Halton. This analysis indicates flaws in a recent re-evaluation of Scarborough Bluffs sediment interpreted as solely lacustrine and not directly affected by glaciers. 相似文献
17.
The adsorption of three copper species, the hydrated cupric ion, bisglycine Cu(II) and a Cu(II)-humic acid complex, on montmorillonite and imogolite at pH 7 was investigated by electron paramagnetic resonance (EPR) spectroscopy. The spectra of the supernatant solutions indicated that adsorption of the glycine complexes was very much less than that of the uncomplexed ion for both minerals and that montmorillonite adsorbed significantly more Cu from the humic acid solution than did imogolite. In every case the adsorbed Cu was characterized by more than one type of chemical environment and the spectral parameters show differences between the adsorbed species depending on their freedom of movement and their mode and site of adsorption. Qualitatively similar spectra were obtained when the uncomplexed ion was adsorbed on either of the mineral species and it is suggested that simple Cu(II) ions were involved and that their coordination environments comprised water molecules and hydroxyl groups. With the bisglycine Cu(II) complexes, the spectra were characterized by two components which may be accounted for by adsorption at two different types of site in the structures. In each case one component had parameters that are similar to those of the bisglycine Cu(II) in the solid state, but the second component in the spectra of the montmorillonite sample was quite different to that obtained with imogolite. The Cu(II)-humic acid complex with montmorillonite gave spectra that were similar to that from copper humate, but with imogolite the spectra from the Cu(II)-humic acid system were similar to those obtained with the uncomplexed Cu(II) ion, indicating that imogolite is able to extract copper from humic acid. 相似文献
18.
XING Li WANG Yikun Eric SNIVELY ZHANG Jianping DONG Zhiming Michael E. BURNS Philip J. CURRIE 《《地质学报》英文版》2015,89(1):1-11
The paired cranial crests of Sinosaurus(Theropoda) have been hypothesized as too weak to resist mechanical loads during combat. Finite element analysis(FEA) is used to test this hypothesis, first with geometry obtained through direct laser scanning of a well-preserved fossil of the crest, and then with two conceptual FE models of both crests analyzing the structure-deformation effects of fenestration. In the original fossil model, under direct loading on the dorsal faces of the crest, we found that the areas surrounding cavities on the crest experience shear stress that implies a high chance of material failure – the fracture of bone. In the conceptual model, a series of computational studies were conducted with varying loading directions. One simulation found that the shear stress and strain in the material around the cavity presented more deformation compared with the conceptual model without the cavities, and under this morphologically realistic scenario the loading conditions would result in local bone fractures. These model-based computational results indicate that the crest could not resist high loads, because it could not effectively decentralize the loading stress. Future investigations need to focus on more comprehensive computational experiments with more conditions, e.g. dynamical loading conditions, and direct palaeontological evidence. 相似文献
19.
A new mamenchisaurid dinosaur, Eomamenchisaurus yuanmouensis gen et sp. nov. is erected based on an incomplete skeleton from the Zhanghe Formation, the Middle Jurassic of Yuanmou, Yunnan Province. The new taxon is characterized by absence of pleurocoels in dorsal vertebrae and the dorsal verterbrae with slightly convex anterior articular surfaces, moderately concave posterior articular surfaces; the fourth trochanter is developed posteromedially on the femur; length ratio of the tibia to the femur is approximately 0.64; and the shaft of the ischium is rod-like. Two fused centra of the posterior dorsal vertebrae （the presumed 9th and the 10th dorsal vertebrae） are similar to those in other mamenchisaurid dinosaurs, including Mamenchisaurus hochuanesis, M. youngi and Chuanjiesaurus anaensis. Therefore, fusion of centra of the ninth and the tenth dorsal vertebrae can be recognized as a synapomorphic character of the Mamenchisauridae. 相似文献
20.
Isolated left prefrontal, left squamosal and atlas of titanosaur dinosaurs are described and compared. They come from the Late Cretaceous Serra da Galga Member of the Marília Formation at the Serra do Veadinho region, Peirópolis (Uberaba County, Minas Gerais State, Brazil). Due to the sparse cranial elements of titanosaurs already known from Brazil, these specimens are noticeable to be presented. In addition, the atlas vertebra is described for the first time for Brazilian titanosaurs. The morphology of the cranial bones closely resembles lithostratian titanosaurs, such as Rapetosaurus, rather than basal titanosaurs. The atlas is similar to that of other titanosaurs, suggesting that the anatomy of this element seems to be more conservative than other vertebral elements, in which vertebral laminae play an important rule in titanosaur taxonomy. 相似文献