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1.
The Late Triassic Tiki Formation has yielded five isolated nearly complete claws or ungual phalanges from a fossil locality, which are described in detail and compared with other Late Triassic tetrapods. Of these, four ungual phalanges are slender, asymmetric, ventrally recurved, transversely compressed, and contain deep collateral grooves on either side, a low median keel on the proximal articular surface and a prominent proximoventral flexor tubercle showing their high similarity to the theropod dinosaurs. The remaining claw is unlike that of any theropods in terms of high robusticity and near symmetry. However, as in dinosaurs it is ventrally recurved and contains deep lateral grooves, a small flexor tubercle, lateromedially extended proximal articular surface with a distinct median keel and is considered as belonging to an indeterminate dinosaur. Although it is not possible to ascertain whether the unguals belong to a single taxon or multiple taxa, this new find points towards the presence of small dinosaurs in the Late Triassic Tiki fauna.  相似文献   

2.
安徽省黄山地区恐龙(足迹)脚印化石的初步研究   总被引:8,自引:0,他引:8  
简要报道了安徽省黄山地区所发现的恐龙足迹化石。从脚印的形态和足迹上看,至少有三种不同的恐龙(蜥脚类、兽脚类、鸟脚类)共同生存过,其中多数恐龙为两足行走性的。记述了两个典型的小型兽脚类和小型鸟脚类恐龙所留下的脚印化石。黄山地区恐龙足迹、骨骼化石及其蛋化石的发现,对于研究晚白垩世恐龙生活习性以及古气候环境均有着一定的意义。  相似文献   

3.
湖北安陆新的恐龙蛋类型的发现及其意义   总被引:4,自引:1,他引:3  
本文记述的恐龙蛋化石标本,采自湖北省江汉盆地公安寨组下部.蛋化石保存完好.在普通光学显微镜和扫描电镜下观察,蛋壳的显微结构完整,清晰可见.根据钙质蛋壳基本结构单位的形态及排列特征,笔者建立了—新属,新种——Dendroolithus wangdianensis gen. et sp. nov.,代表恐龙蛋类一个新科——Dendroolithidae fam. nov.此外,残存的卵壳膜纤维化石的发现,将为进一步研究恐龙蛋卵壳膜的结构和氨基酸组成提供宝贵材料.  相似文献   

4.
内蒙古上白垩统二连组一长颈的镰刀龙类(英文)   总被引:1,自引:0,他引:1  
镰刀龙类 (又称“懒龙”)是一类奇特的植食性兽脚类恐龙 ,化石记录主要局限于亚洲白垩纪地层中。由于镰刀龙类极其特化的形态和化石材料的局限性 ,这类恐龙的系统位置存在较多的争议。最近的发现 (RussellandDong ,1 994;Xuetal.,1 999)表明这类恐龙属于虚骨龙类 ,但其更为具体的系统位置依然存在争议 (Sues ,1 997;MakovickyandSues,1 998;Xuetal.,1 999;Sereno,1 999)。新发现于内蒙古苏尼特左旗赛罕高毕上白垩统二连组的镰刀龙类化石材料代表这类恐龙的一个新属种。杨氏内蒙古龙 (Neimongosaurusyangigen .etsp .nov .)的正型标本为一较为完整的骨架 ,是已知镰刀龙类当中第一件在同一个体中保存了大多数脊椎和几乎所有肢骨的标本。依据以下特征将内蒙古龙归入镰刀龙超科 :U形的下颌联合部、齿骨前端向下弯曲、齿骨前部没有牙齿、牙齿有一个收缩的基部、近圆形的齿根和叶形的齿冠、前部颈椎的神经脊低矮而轴向较长、后部颈椎背视呈X形、肱骨近端角状、肱骨有后转子、肱骨的尺骨髁和挠骨髁位于前部并为一狭窄槽分开、肠骨的耻骨柄细长而坐骨柄短以及跖部短。内蒙古龙的以下特征区别于其他镰刀龙类 :前部尾椎的横突下部有一圆形的窝 ,桡骨二头肌结节非常发育 ,后足趾节近端跟部非常发育 ,胫骨的腓骨嵴长  相似文献   

5.
辽西下白垩统九佛堂组尾羽龙类—新属(英文)   总被引:2,自引:0,他引:2  
记述了一件采自辽西热河群九佛堂组一新的窃蛋龙类:义县似尾羽龙(Similicaudipteryx yixianensis gen.et sp.nov.),并依据其和尾羽龙属的相似特征,及其匕首状的尾综骨,肠骨、踱骨和脚趾的形态等将其归入窃蛋龙类的尾羽龙科,但其所具有的一些特征也不同于该科已建立的尾羽龙属,如尾综骨的形态和较大的个体等。该化石具有许多典型的窃蛋龙类的特征,如短尾、较短的前肢等,有别于其他窃蛋龙类的特征还包括耻骨和肠骨的长度比为1.46,背椎上发育2个大而深的椎体下突、背椎侧部具孔等。义县似尾羽龙是又一类具有真正尾综骨的恐龙,表明尾综骨这一曾经被认为是鸟类特有的结构可能是在恐龙中独自演化的。它具有一些进步的特征如具尾综骨等,但同时也具有一些原始的特征如5个愈合的荐椎,耻骨联合长,表明在窃蛋龙类中存在着特征的镶嵌进化现象。似尾羽龙与驰龙类、其他窃蛋龙类等恐龙一样,脚趾并没有对握,已有的证据说明完全的对握目前还只是出现于鸟类中。根据其短尾、中部收缩的趾骨和灵巧的身体等都表明它是一类适于快速奔跑的动物。目前为止,已知的尾羽龙类化石均发现于北票四合屯地区的义县组下部尖山沟层(段),距今约125Ma。新标本发现于义县西二虎桥地点,属于九佛堂组,距今约120Ma,这也是迄今为止在九佛堂组发现的惟一一件尾羽龙类化石,对研究早白垩世窃蛋龙类的演化和热河生物群恐龙组合的特征具有重要的意义。  相似文献   

6.
7.
山东莱阳晚白垩世恐龙蛋化石一新类型   总被引:4,自引:0,他引:4  
山东莱阳是中国最早发现的含有丰富的晚白垩世恐龙及恐龙蛋化石产地。上个世纪50~60年代,周明镇(1951,1954)及杨钟健(1954,1959,1965)对莱阳首次发现的恐龙蛋化石进行了研究。1974年,赵资奎、蒋元凯在前人工作基础上,采用显微镜技术方法重新研究了莱阳恐龙蛋壳的显微结构,结果发现它们的显微结构有很大差异。根据赵资奎(1975)提出的恐龙蛋分类方法(Parataxonomy),将莱阳地区已发现的恐龙蛋分别归入圆形蛋科(spheroolithidae)、椭圆形蛋科(Ovaloolithidae)和长形蛋科(Elongatoolithidae)等3个科,共5个属12个种(赵资奎,1979,1993)。最近,大连自然博物馆在整理馆存的化石标本时,发现有4枚形状为扁圆形的恐龙蛋化石是1973年10月从山东莱阳将军顶采集到的。根据目前有关莱阳地区晚中生代地层划分修订的标准(胡承志等,2001),这些标本的出土层位应为上白垩统王氏群将军顶组。我们的初步观察表明,蛋化石的形状、大小及其蛋壳显微结构特征与上述已报道的莱阳恐龙蛋3个类群的明显不同,在此简单记述,以期对莱阳地区晚白垩世恐龙蛋群的综合研究提供些许资料。  相似文献   

8.
Abstract:  A new genus and species of diplodocid sauropod (Sauropoda, Diplodocoidea), Australodocus bohetii , is described. The type material from the Upper Jurassic (Tithonian) Tendaguru Beds of Tanzania, East Africa, consists of two successive mid-cervical vertebrae. These vertebrae do not show the extreme elongation of the cervical vertebrae that is diagnostic for Tornieria , and, apart from proportional differences, exhibit four autapomorphic characters not seen in other diplodocids: (1) pleurocoel weakly developed; (2) ridge posterolateral to the anterior condyle strongly posteroventrally orientated; (3) triangular pneumatic cavity ventral to the prezygapophysis, enclosed by the lateral ramus of the centroprezygapophyseal lamina and an anteriorly extended prezygodiapophyseal lamina; and (4) prominent prezygapophyseal process pointed, laterally keeled and surpassing the prezygapophysis anteriorly. Australodocus bohetii is the second diplodocid known from Tendaguru, and thereby the second diplodocid known from Gondwana. This impedes the customary reference of isolated East African diplodocid material to Tornieria , which can now only be assigned to Diplodocidae indet. The find supports previously proposed vicariance models of diplodocid palaeobiogeography.  相似文献   

9.
Abstract:  Xenoposeidon proneneukos gen. et sp. nov. is a neosauropod represented by BMNH R2095, a well-preserved partial mid-to-posterior dorsal vertebra from the Berriasian–Valanginian Hastings Beds Group of Ecclesbourne Glen, East Sussex, England. It was briefly described by Lydekker in 1893, but it has subsequently been overlooked. This specimen's concave cotyle, large lateral pneumatic fossae, complex system of bony laminae and camerate internal structure show that it represents a neosauropod dinosaur. However, it differs from all other sauropods in the form of its neural arch, which is taller than the centrum, covers the entire dorsal surface of the centrum, has its posterior margin continuous with that of the cotyle, and slopes forward at 35 degrees relative to the vertical. Also unique is a broad, flat area of featureless bone on the lateral face of the arch; the accessory infraparapophyseal and postzygapophyseal laminae which meet in a V; and the asymmetric neural canal, small and round posteriorly but large and teardrop-shaped anteriorly, bounded by arched supporting laminae. The specimen cannot be referred to any known sauropod genus, and clearly represents a new genus and possibly a new 'family'. Other sauropod remains from the Hastings Beds Group represent basal Titanosauriformes, Titanosauria and Diplodocidae; X. proneneukos may bring to four the number of sauropod 'families' represented in this unit. Sauropods may in general have been much less morphologically conservative than is usually assumed. Since neurocentral fusion is complete in R2095, it is probably from a mature or nearly mature animal. Nevertheless, size comparisons of R2095 with corresponding vertebrae in the Brachiosaurus brancai holotype HMN SII and Diplodocus carnegii holotype CM 84 suggest a rather small sauropod: perhaps 15 m long and 7600 kg in mass if built like a brachiosaurid, or 20 m and 2800 kg if built like a diplodocid.  相似文献   

10.
Abstract: A new oviraptorid is described on the basis of a partial forelimb collected from the Upper Cretaceous redbeds of Bayan Mandahu, Inner Mongolia. Machairasaurus leptonychus, gen. et sp. nov. is diagnosed by slender, weakly curved manual unguals, reduced flexor tubercles, penultimate phalanges that are subequal in length to the preceding phalanges, and short, robust manual digits. Machairasaurus is found to be a member of the Ingeniinae, along with Ingenia yanshini, Heyuannia huangi, Conchoraptor gracilis, and Nemegtomaia barsboldi. Machairasaurus exhibits unusual proportions of the manus, suggesting that the manus was not primarily used to grasp prey. Instead, Machairasaurus and other oviraptorids are likely to have fed largely on plant material. The recognition of a previously unknown oviraptorid at Bayan Mandahu provides further evidence that the Bayan Mandahu dinosaur assemblage is distinct from that found at the Djadokhta Formation exposures at Bayn Dzak, Tugriken Shireh, and Ukhaa Tolgod. Given that these localities are separated by just a few hundred kilometres and represent similar palaeoenvironments, marked differences in the fauna suggest that the Bayan Mandahu Formation of Inner Mongolia is not coeval with the known Djadokhta localities in Mongolia.  相似文献   

11.
A new hadrosaurid dinosaur, Arenysaurus ardevoli gen. et sp. nov., from the Late Maastrichtian of Aren (Huesca, South-central Pyrenees) is described on the basis of a partial, articulated skull, mandibular remains and postcranial elements, including vertebrae, girdle and limb bones. Arenysaurus is characterized by having a very prominent frontal dome; nearly vertical prequadratic (squamosal) and jugal (postorbital) processes, and deltopectoral crest of the humerus oriented anteriorly. Moreover, it possesses a unique combination of characters: short frontal (length/width approximately 0.5); midline ridge of parietal at level of the postorbital-squamosal bar; parietal excluded from the occiput; squamosal low above the cotyloid cavity. A phylogenetical analysis indicates that Arenysaurus is a rather basal member of Lambeosaurinae and the sister-taxon to Amurosaurus and the Corythosaurini-Parasaurolophini clade. The phylogenetic and biogeographical relationships of Arenysaurus and other lambeosaurines suggest a palaeogeographical connection between Asia and Europe during the Late Cretaceous.  相似文献   

12.

Background

The Yellow Cat Member of the Cedar Mountain Formation (Early Cretaceous, Barremian?) of Utah has yielded a rich dinosaur fauna, including the basal therizinosauroid theropod Falcarius utahensis at its base. Recent excavation uncovered a new possible therizinosauroid taxon from a higher stratigraphic level in the Cedar Mountain Formation than F. utahensis.

Methodology/Principal Findings

Here we describe a fragmentary skeleton of the new theropod and perform a phylogenetic analysis to determine its phylogenetic position. The skeleton includes fragments of vertebrae, a scapula, forelimb and hindlimb bones, and an ischium. It also includes several well-preserved manual unguals. Manual and pedal morphology show that the specimen is distinct from other theropods from the Cedar Mountain Formation and from previously described therizinosauroids. It is here named as the holotype of a new genus and species, Martharaptor greenriverensis. Phylogenetic analysis places M. greenriverensis within Therizinosauroidea as the sister taxon to Alxasaurus + Therizinosauridae, although support for this placement is weak.

Conclusions/Significance

The new specimen adds to the known dinosaurian fauna of the Yellow Cat Member of the Cedar Mountain Formation. If the phylogenetic placement is correct, it also adds to the known diversity of Therizinosauroidea.  相似文献   

13.
Reexamination of the holotype of Riabininohadros weberae from the Upper Cretaceous (upper Maastrichtian) of the Crimean Peninsula (Besh-Kosh) allowed determination of previously unknown elements of the femur, astragalus, and calcaneus. This taxon shows a set of primitive characters observed in iguanodontids and basal ornithischians and is referred to as Styracosterna indet. The second dinosaur specimen from Crimea (Aleshino) is a fragmentary skeleton, including cervical and dorsal vertebrae. It possibly belongs to advanced iguanodontids or primitive hadrosauroids. Thus, in the Maastrichtian of the Crimean Peninsula, at least two dinosaur species coexisted.  相似文献   

14.
15.
描述湖北郧县淅川盆地晚白垩世地层中产出的蜥脚类恐龙化石。标本不关联保存于马家村组中段灰绿色含钙泥质粉砂岩中,材料包括牙齿、脊椎和肢骨化石等。从愈合特征(如分离的椎体和椎弓)分析,这些化石至少由2个未成年个体组成。这些化石体现出的特征组合,如股骨近端外侧突出,近端外缘向内侧倾斜,荐前椎气腔构造发育,以及牙齿呈细长的棒状,表明湖北郧县马家村组地层发现的蜥脚类可归入巨龙形类中的多孔椎龙类或者更进步的类群。新材料的发现对于进一步了解中国乃至东亚地区白垩纪晚期的蜥脚类恐龙分布和演化具有一定的意义。  相似文献   

16.
Abstract:  Vertebrae of Suuwassea demonstrate an interesting combination of plesiomorphies and autapomorphies among known members of the Flagellicaudata. The cranial cervical vertebrae have proportions close to Diplodocus but resemble those of Apatosaurus except by having greatly reduced cranial and caudal spinozygapophyseal laminae. As a result, they have craniocaudally compressed, caudally positioned spinous processes excavated on all sides by fossae. The cranial thoracic vertebrae are again similarly proportioned as those of Diplodocus but are morphologically similar to those of Apatosaurus . The most distinguishing feature of Suuwassea caudal vertebrae are the short, amphiplatyan, distalmost 'whiplash' caudal vertebrae. These may be either a retention of or a reversal to the plesiomorphic sauropod condition because classic flagellicaudatan, biconvex distalmost caudals occur in the Middle Jurassic of England.  相似文献   

17.
浙江天台盆地晚白垩世恐龙蛋新类型(英文)   总被引:1,自引:0,他引:1  
浙江天台盆地上白垩统赖家组和赤城山组是我国最重要的恐龙蛋化石产出地层之一。近年来,我们对天台盆地陆相红层中的恐龙蛋化石层位进行了详细厘定,对恐龙蛋类型进行了系统描述,并对前人报道的一些属种进行了分类订正。研究显示,天台恐龙蛋化石群基本上可分为7蛋科、12蛋属和15蛋种,代表了我国晚白垩世早期的恐龙蛋化石组合。本文简要报道了主要产自天台盆地赤城山组的双塘似蜂窝蛋(新蛋属、新修订种)、木鱼山半蜂窝蛋(新蛋属、新蛋种)、国清寺副蜂窝蛋(新修订种)、天台棱柱形蛋(新修订种)和张头槽马赛克蛋(新蛋属、新修订种)等3新蛋属、5新蛋种和修订种的主要鉴定特征,并建立一新蛋科——似蜂窝蛋科。  相似文献   

18.
The Early Cretaceous fauna of Victoria, Australia, provides unique data on the composition of high latitude southern hemisphere dinosaurs. We describe and review theropod dinosaur postcranial remains from the Aptian-Albian Otway and Strzelecki groups, based on at least 37 isolated bones, and more than 90 teeth from the Flat Rocks locality. Several specimens of medium- and large-bodied individuals (estimated up to ~8.5 metres long) represent allosauroids. Tyrannosauroids are represented by elements indicating medium body sizes (~3 metres long), likely including the holotype femur of Timimus hermani, and a single cervical vertebra represents a juvenile spinosaurid. Single specimens representing medium- and small-bodied theropods may be referrable to Ceratosauria, Ornithomimosauria, a basal coelurosaur, and at least three taxa within Maniraptora. Thus, nine theropod taxa may have been present. Alternatively, four distinct dorsal vertebrae indicate a minimum of four taxa. However, because most taxa are known from single bones, it is likely that small-bodied theropod diversity remains underestimated. The high abundance of allosauroids and basal coelurosaurs (including tyrannosauroids and possibly ornithomimosaurs), and the relative rarity of ceratosaurs, is strikingly dissimilar to penecontemporaneous dinosaur faunas of Africa and South America, which represent an arid, lower-latitude biome. Similarities between dinosaur faunas of Victoria and the northern continents concern the proportional representatation of higher clades, and may result from the prevailing temperate-polar climate of Australia, especially at high latitudes in Victoria, which is similar to the predominant warm-temperate climate of Laurasia, but distinct from the arid climate zone that covered extensive areas of Gondwana. Most dinosaur groups probably attained a near-cosmopolitan distribution in the Jurassic, prior to fragmentation of the Pangaean supercontinent, and some aspects of the hallmark 'Gondwanan' fauna of South America and Africa may therefore reflect climate-driven provinciality, not vicariant evolution driven by continental fragmentation. However, vicariance may still be detected at lower phylogenetic levels.  相似文献   

19.
内蒙古查布地区下白垩统巨齿龙足印化石   总被引:9,自引:0,他引:9  
内蒙古鄂尔多斯市鄂托克旗查布地区下白垩统中产有大量的蜥脚类和兽脚类恐龙足迹及鸟类足迹化石,作者对这个地区的足迹化石进行全面普查,发现许多新暴露出来的恐龙足迹化石,包括兽脚类恐龙足迹一新属新种Chapuslockleyiichnogen.etichnosp.nov.属于巨齿龙类(megalosaurid)所留。与兽脚类足迹保存在一起的蜥脚类足迹Brontopodusbirdi分布凌乱,反映了造迹恐龙搏斗的场面。通过测量连续的兽脚类足迹计算,Chapuslockleyi的造迹恐龙的行走速度为4.33km/h。通过足迹化石还识别出造迹恐龙的病态特征。  相似文献   

20.
Abstract: Material from a new titanosaur from the Bauru Basin (Bauru Group), Brazil is described and compared with well‐known titanosaurs. Adamantisaurus mezzalirai gen. et sp. nov. is based on six articulated anterior caudal vertebrae and two haemapophyses collected from the Adamantina Formation, which is considered to be Campanian–Maastrichtian? in age. Adamantisaurus mezzalirai is characterized by the following combination of characteristics: anterior caudal vertebrae with straight or slightly backwardly‐projecting neural spines with strongly expanded distal ends, stout prespinal lamina, very wide pre‐ and postzygapophyseal articular facets, and concave postzygapophyseal articular facets on anterior caudal vertebrae. Although our cladistic analysis has produced equivocal results, Adamantisaurus mezzalirai shares with DGM ‘Series B’ (Peirópolis titanosaur) and Aeolosaurus the presence of postzygapophyses with concave articular facets, and shares with DGM ‘Series B’ the presence of laterally expanded neural spines and stout prespinal lamina. Additionally, A. mezzalirai shares with DGM ‘Series’ C (other titanosaur from Peirópolis) the presence of short neural spines.  相似文献   

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