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1.
辽宁锦州义县早白垩世义县组发现了一种新型燕鸟(Yanornis)化石.该新型化石具有燕鸟的典型特征,如齿骨直且约占头骨全长的2/3、每侧约含20枚牙齿,颈椎细长,异凹型.愈合荐椎包括9枚脊椎,前肢约为后肢长的1.1倍.近端脚趾较其它趾节长和粗壮.然而,该新型化石部分特征又不同于燕鸟的模式种——马氏燕鸟(Yanornis martini),如其肱骨三角肌脊强烈发育,约为肱骨长度的一半.尺骨、桡骨及手部近等长,均长于肱骨.耻骨联合部较短,与尾综骨等长,不到耻骨长度的1/6.腓骨较长,约为股骨长度的4/5,约为胫跗骨长度的2/3.跗跖骨较短并完全愈合,不及胫跗骨长度一半.根据该新型化石的独特性及其与义县鸟、松岭鸟和马氏燕鸟的特征对比,笔者建立了燕鸟一新种——国章燕鸟(Yanornis guozhangisp.nov.).此外,国章燕鸟(新种)颈部还保存有3条鱼化石,这一特殊现象为研究燕鸟的生活习性和发育模式提供了重要信息.  相似文献   

2.
Yabeinosaurus was the first lizard genus described from the Early Cretaceous Jehol Biota of China. The holotype of the type species, Y. tenuis, is an immature skeleton but it has been lost for decades. A second species, Y. youngi, was erected based on another immature skeleton and is distinguished by its longer, more gracile limbs. In 2001, a juvenile skeleton from the Jingangshan locality of Liaoning was designated as the neotype for Y. tenuis. Subsequently, several further specimens from other localities, juvenile and adult, have been attributed to this species. Here we describe a second lizard specimen from the neotype locality. In anterior tooth shape, finger-like mandibular angular process, cranial sculpture, maxilla shape, and short, robust humerus, the new specimen resembles adult and subadult material currently attributed to Y. tenuis, but it differs in having bicuspid posterior teeth and a straight rather than a hooked angular process of the mandible. We propose a new species (Y. bicuspidens sp. nov.) for this specimen which represents the first occurrence of bicuspid teeth in an Early Cretaceous lizard from China. However, the recognition of a second species at the neotype locality raises a taxonomic problem. Due to the immaturity of the designated holotype and neotype of Y. tenuis, they cannot be coded for the jaw and dental characters that distinguish the two robust-limbed species. This renders Yabeinosaurus tenuis a nomen dubium. Here we propose that Yabeinosaurus tenuis should be treated as a historic taxon, permitting retention of the generic name under ICZN rules, and erect a second new species (Y. robustus sp. nov.) for the principal robust-limbed morphotype in the Jehol Biota with monocuspid posterior teeth and a hooked angular process.  相似文献   

3.
This paper describes an avialian bird from the Early Cretaceous Jiufotang Formation in Yixian county, western Liaoning, China, which is named as Shenzhouraptor sinensis by Ji et al. on July 15, 2002. Shenzhouraptor sinensis is characterized by no teeth in its mouth, the forelimbs longer than the hindlimbs, a long tail with more than 23 caudal vertebrae, U-shaped wishbone, and remiges longer than the total length of ulna and manus. It is certain that the new avialian bird is really capable of powerful flight, representing a missing link between theropod dinosaurs and birds.  相似文献   

4.
The Early Cretaceous lizard Yabeinosaurus was one of the first taxa described from the now famous Jehol Biota of northeast China. Misinterpreted for more than 60 years and misclassified as a gekkotan based on juvenile specimens, it is now recognised to be a large, well-ossified lizard with an extended period of skeletal maturation. Here we describe two additional complete specimens of Yabeinosaurus that provide new information on skeletal morphology, most notably of the skull, pectoral girdle, and tail. Both specimens also preserve gut contents, showing that large individuals took vertebrate prey, including fish. A more complete understanding of Yabeinosaurus permits a review of the type specimen of Yabeinosaurus youngi. Skull traits used to distinguish Y. youngi from Yabeinosaurus tenuis are invalid but, as noted by Hoffstetter, the two species differ markedly in limb proportions. Attribution of Young’s specimen to Yabeinosaurus is equivocal, but could potentially extend the temporal range of the lineage into the Jurassic. A new phylogenetic analysis based on a morphological data set places Yabeinosaurus on the stem of Scleroglossa, as the sister taxon of the contemporaneous Japanese lizard Sakurasaurus.  相似文献   

5.
记辽宁一新翼龙化石(喙嘴龙亚目)   总被引:21,自引:0,他引:21  
姬书安  季强 《江苏地质》1998,22(4):199-206
记述了辽宁北票四合屯炒米甸子组中一新翼龙化石,该翼龙个体极小,两翼展开仅约40cm。化石具有同形齿、长尾、极短的翼掌骨和非常发育的后肢第Ⅴ趾等特征,因而无疑可归入喙嘴龙亚目喙嘴龙科(Rhamphorhynchidae),并代表一新属种弯齿树翼龙(Dendrorhynchuscurviden-tatusgen.etsp.nov.)。该化石是我国及东亚晚侏罗世喙嘴龙类翼龙的首次记录,它的发现有力地表明包括中华龙鸟和孔子鸟在内的辽西四合屯化石层的地质时代应为晚侏罗世。  相似文献   

6.
<正>We report on a new species of enantiornithine bird from the Lower Cretaceous Qiaotou Formation of northern Hebei,China.The new taxon,Shenqiornis mengi gen.et sp.nov.,possesses several enantiornithine synapomorphies but is unique from other known species.The specimen has a well-preserved skull that reveals new information about enantiornithine cranial morphology.The new taxon possesses a large postorbital with a long tapering jugal process indicating that some enantiornithines may have had a fully diapsid skull,as in Confuciusornis.The tooth morphology of the specimen is unique and likely represents a previously unknown trophic specialization within Enantiornithes.  相似文献   

7.
A specimen collected from the Lower Cretaceous Yixian Formation of western Liaoning, China, represents a new genus and species of troodontid theropod. The new taxon is named and described on the basis of the holotype and the only known specimen, which comprises an articulated skeleton with the presacral vertebral, shoulder girdle and forelimbs missing as preserved. Diagnostic features of the new species include nasals that are sinusoid in lateral view, absence of a passage connecting the antorbital and maxillary fenestrae, relatively large teeth, plate-like chevrons forming a band along most of the length of the tail, and a long neck between the femoral head and shaft. The temporal constraints of the three paravian groups (Troodontidae, Dromaeosauridae and Aves) combined with the character distributions among the earliest known troodontids indicate a rapid evolution at the base of the Troodontidae.  相似文献   

8.
A new baby pterodactyloid pterosaur with soft tissue preserved, Ningchengopterus liuae gen. et sp. nov., is erected based on a nearly complete skeleton with a skull. It was characterized by the skull, slightly longer than the combined length of the dorsal and sacral vertebrae; 50 teeth (including upper and lower jaws); short mid-cervical vertebrae; the humerus and the scapula, equal to that of the wing metacarpal in length; the ulna and the femur, equal to that of the first and third wing phalanx in length, respectively. The similar ratio of the wing phalanx 2 to wing phalanx 1 of Ningchengopterus and Eosipterus implies that Ningchengopterus may be close to the ctenochasmatid pterosaur. However, it may also imply that the isometrically growing of the first two wing phalanges exists among some pterosaurs.  相似文献   

9.
记述了辽宁义县早白垩世九佛堂组的一件初鸟类(Avialae)化石,其嘴里无牙,前肢明显长于后肢,尾巴由20多节尾椎组成,叉骨呈U字形,飞行羽毛超过了身体的长度。各种特征表明,新发现的初鸟类真正具有了飞行能力,代表了恐龙向鸟类演化过程中的又一中间环节。正式将其命名为中华神州鸟(Shenzhouraptorsinensisgen.etsp.nov.)。  相似文献   

10.
The terrestrial lizard fossil record of Gondwana is very scarce. Few lizards, from mostly fragmentary fossils, have been identified in Madagascar, Tanzania, Morocco, South Africa, India and South America. Among the South American specimens there are basal Squamata forms (Olindalacerta and Tijubina) and a possible iguanid (Pristiguana) form Brazil. In Argentina gondwanian terrestrial lizards are represented by a putative iguanid and a small, poorly preserved dentary. This last specimen, recovered from the Anacleto Formation (Neuquén Group, Río Colorado Subgroup) in vicinity of the locality of Cinco Saltos (Río Negro Province), is here described formally. Comparisons with extant lizards indicate more affinity of the fossil with the Scincomorpha (non Scincophidia) than with any other group of lizards. This finding suggests that lizards were probably better represented and more diverse in the Mesozoic of South America than previously thought, although the fossil record is, at the moment, much poorer than in Laurasia.  相似文献   

11.
Jinfengopteryx is a newly uncovered Archaeopteryx-like avialan bird outside Germany, which was found from the Jehol Biota of northern Hebei in northeastern China. It shares many characters only with Archaeopteryx by the possession of three fenestrae in the antorbital cavity, 23 caudal vertebrae and long tail feathers attached to all the caudal vertebrae. But the former differs from the latter in the relatively short and high preorbital region of skull, more and closely packed teeth, much shorter forelimb compared to hindlimb. Such differences indicate Jinfengopteryx is even slightly more primitive than Archaeopteryx, although both birds can be placed at the root position of the avialan tree based on cladistic analysis. Shenzhouraptor is suggested to be slightly more advanced than Jinfengopteryx + Archaeopteryx, supported by some derived features in teeth, shoulder girdles and forelimbs such as the reduction of tooth number, dorsolaterally directed glenoid facet, very long forelimb and comparatively short manus. Meanwhile, the tail of Shenzhouraptor shows more primitive characters than those of Jinfengopteryx and Archaeopteryx, e.g., the strikingly longer tail composed of more caudal vertebrae and the long tail feathers attached only to distal caudal segments. The mixed primitive and advanced characters reveal the evident mosaic evolution among long-tailed avialan birds.  相似文献   

12.
A new species of cladid crinoid, Hylodecrinus cymrus, is described from the Pembroke Limestone Group (Mississippian, Tournaisian, Courceyan) of West Angle Bay in south Pembrokeshire, Wales. It has a medium bowl‐shaped aboral cup, with strong ridges extending across the basals and radials forming pits at the plate corners. It is most similar to the late Tournaisian H. carinatus (Hall, 1861) of North America but differs in having less strongly cuneate brachials that are longer than wide with more subtle carinae on the aboral side. This specimen represents the first report of this genus from Europe, which most probably migrated from North America. Copyright © 2013 John Wiley & Sons, Ltd.  相似文献   

13.
巨大华夏龙   总被引:1,自引:1,他引:0  
赵喜进  王克柏  李敦景 《地质通报》2011,30(11):1671-1688
巨大华夏龙(Huaxiaosaurus aigahtens Zhao, gen. & sp., nov.)是一种性情温和的素食性恐龙,产于山东 诸城,生活在距今100Ma前的中生代晚期。巨大华夏龙是从许多同种个体中选择后组装成的一具骨架,其体高11.3m, 体长18.7m,是目前世界上最高大的鸟脚类个体。巨大华夏龙前肢短,后肢粗长,是继巨型山东龙和巨大诸城龙之后 又一新的发现。  相似文献   

14.
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   

15.
<正>A new dinosaur Chuxiongosaurus lufengensis gen.et sp.nov.is erected based on a nearly complete skull.The taxon is characterized by the lacrimal perpendicular to the ventral margin of the upper jaw,which is similar to that of Thecodontosaurus;a depression present on the dorsal profile of the snout behind the naris;the rostral profile of the maxilla slopes continuously towards the rostral tip;and the presence of 25 dentary teeth.It also displays prosauropod characters such as a relatively long skull,the slope of the maxillary rostral profile,and teeth that do not have basically constricted crowns.The new specimen is more basal than Anchisaurus and represents the first basal sauropod dinosaur from the Early Jurassic of China.  相似文献   

16.
动载荷作用下岩石破坏过程的数值试验研究   总被引:3,自引:0,他引:3  
采用基于细观损伤力学基础上开发的动态版RFPA2D数值模拟软件,对动载荷作用下应力波延续时间、应力波峰值和围压对岩石试样破坏的影响进行了数值研究,结果表明,应力波延续时间较短,则尾随应力波波前的高应力区范围较窄,应力波衰减较快;相反,应力波延续时间较长,则紧跟应力波波前的高应力区范围较大,岩石处于破坏状态的时间延长,岩石的破碎程度加大。此外,存在一个合适的应力波延续时间,过分地加大应力波延续时间,反而不利于岩石裂隙的发育。动载荷的峰值越大,试样的破坏程度越大,当峰值达到一定值时,试样顶部呈现粉碎状,试样从上到下破坏程度逐渐减弱。在冲击载荷作用下的岩石随着围压的增加更难破碎,但当围压增大到一定程度时,岩石会突然失稳破坏。  相似文献   

17.
The partially articulated, distal portion of a left wing finger of a pterosaur from the Crato Formation of northeast Brazil has a T-shaped cross-section to the second and third phalanges. This cross-sectional shape is one of several characters diagnostic of the pterodactyloid pterosaur family Azhdarchidae (Unwin & Lu 1997). Until now, this family of pterosaurs was known exclusively from the Late Cretaceous. The specimen described here may be the first recorded azhdarchid from the southern hemisphere and the earliest recorded member of the family.  相似文献   

18.
巨大华夏龙     
巨大华夏龙(Huaxiaosaurus aigahtens Zhao,gen.&sp.,nov.)是一种性情温和的素食性恐龙,产于山东诸城,生活在距今100Ma前的中生代晚期。巨大华夏龙是从许多同种个体中选择后组装成的一具骨架,其体高11.3m,体长18.7m,是目前世界上最高大的鸟脚类个体。巨大华夏龙前肢短,后肢粗长,是继巨型山东龙和巨大诸城龙之后又一新的发现。  相似文献   

19.
山东的巨大诸城龙   总被引:12,自引:0,他引:12  
巨大诸城龙(Zhuchengosaurus maximus Zhao,gen.et sp.nov.)是一种性情温和的草食性恐龙,产于山东诸城,生活在距今100 Ma前的中生代晚期.巨大诸城龙是从几个同种个体中选择后组装成的一具骨架,其身高9.1 m,身长16.6 m,它是目前世界最高大的鸟脚类个体.巨大诸城龙前肢细小,后肢粗长,荐椎由9个椎体组成,是继巨型山东龙之后的又一新的发现.  相似文献   

20.
谭锴  卢立伍  陈晓云  靳悦高 《地质通报》2018,37(10):1783-1788
描述了发现于中国东北地区中生代地层中的蛙类化石一新属、新种,即莫旗蒙蟾(新属、新种)Mengbatrachus moqi gen. et sp. nov.。化石产于内蒙古自治区最东部与黑龙江省相邻的莫旗。该类化石的的主要特征如下:头宽大于头长,上颌骨和前颌骨具有密集排列的牙齿;两鼻骨在中线相接;副蝶骨长条状;翼骨较大,鳞骨、上肩胛骨发育,乌喙骨近端膨大显著;荐前椎8个,脊椎横突发育;第Ⅱ—Ⅳ荐前椎具有短粗肋骨;肋骨单头,近端膨大;荐椎横突呈近似棒状,远端仅稍加宽;尾杆骨上有一对椎后横突;胫跗骨和腓跗骨仅在近端和远端愈合。这是除辽蟾外,在中国发现的另一新的中生代无尾两栖类化石。  相似文献   

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