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1.
辽宁晚株罗世—早白垩世一长颈双弓类爬行动物   总被引:5,自引:1,他引:4  
初步记述了采自辽西凌源地区晚侏罗世-早白垩世义县组一新的双弓类水生爬行动物化石材料,并确立其为一新属瓣种-凌源潜龙。化石产于凌源大王杖子乡范杖子村义县组含火山灰的灰白色涌相页岩中,与狼鳍鱼共生。  相似文献   

2.
高峻 《化石》2002,(3):6
今年第二期的《化石》杂志刊登了河北经贸大学李小栋、张爱芹撰写的题为《罕见的新生代双弓类长颈水生爬行动物化石———山旺中国龙》一文以及上海复旦大学物理系教授孙震老先生撰写的《贵州发现长颈“背帆龙”》一文。笔者在仔细阅读两文及观察对应图版照片后对这几位作者在文中提出的错误观点予以纠正。笔者对这几位化石爱好者在地质学、古脊椎动物学等学科基础知识的匾乏和对古生物化石研究缺乏实践经验而产生的错误表示理解。在“山旺中国龙”一文中两位作者着重介绍了胡氏贵州龙 (Keichousaurushui)和凌源潜龙(Hy…  相似文献   

3.
1999年高克勤、唐治路、汪筱林 (古脊椎动物学报 ,第 3 9卷 ,第 1期 )根据产自辽宁省凌源市宋杖子乡义县组的一件标本建立了凌源潜龙 (Hyphalosauruslingyuanensis)。同年 ,李建军等 (北京自然博物馆研究报告 ,第 56期增刊 )根据同一块标本的另一半 (负模 )建立凌源中国水生蜥 (Sinohydrosauruslingyuanensis)。最近JoshuaB .Smith等在北美的“JournalofVertebratePaleontology” (第 2 1卷 ,第 2期 ,2 0 0 1 )上发表文章讨论了两个名称…  相似文献   

4.
早白垩世热河生物群一新的有尾两栖类   总被引:39,自引:5,他引:34  
描述了内蒙古宁城下白垩统义县组下部一新的有尾两栖类:奇异热河螈(新属、新种)Jeholotriton paradoxus gen. et sp. nov.。标本保存了完好的相关节的骨架印痕,头骨中的翼 骨具有一个不与上颌骨相连,而与头骨中部相连的前内侧突,这使它区别于其他早期有尾类。  相似文献   

5.
辽西义县组长节锯蜂科(昆虫纲,膜翅目)昆虫化石   总被引:4,自引:0,他引:4  
描述产自辽宁西部北票上园地区和凌源大王杖子义县组长节锯蜂科(Xyelidae)巨长节锯蜂亚科(Macroxyelinae)昆虫化石12种,归于4族8属,其中6新属12新种,包括Angaridyela robusta sp.nov.,Angaridyela exculpta sp.nov.,Angaridyela suspecta sp.nov.,Angaridyela endemica sp.no  相似文献   

6.
记述了贵州兴义法郎组竹杆坡段(中三叠世拉丁期)长颈龙属未定种(Tanystropheus sp.)一幼年个体的不完整骨架。这是该属在欧洲和中东以外的首次发现。新材料仅保存部分颈椎、躯干和前肢。根据特殊的颈椎形态将该标本归入长颈龙属,而区别于另一种长颈的海生原龙类——东方恐头龙(Dinocephalosaurus orientalis)。新标本的腕骨形态简单,骨化程度弱,表明长颈龙是终生水生的动物。“长颈、长颈肋”见于多种不同海生爬行动物(如原龙类、初龙类),它们很可能都以“吞吸”的方式捕食。长颈龙化石在我国的发现进一步验证了中国南方三叠纪海生爬行动物群与欧洲西特提斯动物群(western Tethyan fauna)之间的密切关系。  相似文献   

7.
记述了贵州关岭晚三叠世早期法郎组瓦窑段新的海龙标本:一个基本完整的侧向挤压头骨及下颌(中国科学院古脊椎动物与古人类研究所标本编号V 11860)。根据图版,它与尹恭正等(2000)建立并归入鱼龙目Cymbospondylidae科的孙氏“新铺鱼龙”(Xinpusaurus suni)极为相似。但是由于从文章中得不到头部关键性状的描述,并且本文第一作者到贵阳也不被允许观察标本,目前只有依据与正模图版的对比将V11860标本暂定为孙氏新铺龙相似种(Xinpusaurus cf. X suni)。由于系统分类位置的改变,建议将该属的中文名称由“新铺鱼龙”改为新铺龙。 迄今为止,在所有海龙类头骨中此标本提供了最多可以观察到的性状,包括脑颅侧面的特征。这是一类小型的海龙,吻部中等长度,微微向腹面倾斜;上颌骨前端背向弯曲,此处牙齿扩大且向前平伏;头骨前部的牙齿(前颌骨、上颌骨前部、齿骨)圆锥形,较突出,而靠后部的牙齿可能较圆钝(保存不完整);前颌骨与上颌骨牙齿间无明显间隙;犁骨和翼骨具齿;下颌细长,齿骨联合部窄。长的齿骨大约占下颌长度的2/3。 基于18个性状进行了初步的支序分析,结果表明新铺龙与北美的Nectosaurus?  相似文献   

8.
辽宁凌源及相邻内蒙古南部宁城地区义县组发现多个重要脊椎动物化石地点,通过岩 石地层、脊椎动物生物地层和同位素年代地层对比,建立了该地区义县组地层层序。凌源一宁 城地区义县组有 2个脊椎动物化石层位:下部道虎沟层含 Lycopteraer Ichthyofauna, Psittacosaurus Fauna和Confuciusornis Avifauna等3个动物群,可以与北票尖山沟层的四合 屯脊椎动物化石群对比,层位相当于义县组一、三段;上部大王杖子(大新房子)层含 Lycoptera Ichthyofauna和Liaoxiornis Avifauna等2个动物群,为义县组中部沉积,在四合屯地 区缺失。冀北丰宁四岔口-森吉图地区义县组脊椎动物化石层对应于凌源大王杖子层;滦平 大北沟组为义县组最下部沉积,其上覆的大店子组相当于宁城道虎沟层和北票四合屯义县组 一、三段。热河群义县组和九佛堂组发现3个连续的鸟类群;义县组下部Confuciusornis Avifauna、义县组中部Liaoxiornis Avifauna和九佛堂组Cathayornis-Chaoyangia Avifauna。义 县组和九佛堂组Lycoptera I  相似文献   

9.
变色树蜥骨骼系统的解剖   总被引:1,自引:0,他引:1  
用透明骨骼标本染色法制作变色树蜥的骨骼标本,并对其骨骼系统进行了全面的描述.其骨骼可分为中轴骨骼(包括头骨、脊柱、胸骨、肋骨)和附肢骨骼(包括肩带、腰带、前肢骨、后肢骨).其头骨呈梨形,眼眶完整.颈椎8枚,胸椎4枚,腰椎11枚,荐椎2枚,尾椎多于34枚.有颈肋4对,胸肋4对,腰肋11对.表现出了一系列进化特征,如前颌骨愈合成1块,额骨也愈合成1块,颧骨消失,鳞骨变小,犁骨薄弱,下颌夹板骨与齿骨、冠状骨及隅骨之间的骨缝不明显,愈合程度较高.  相似文献   

10.
记新疆准噶尔盆地中侏罗世一新甲龙   总被引:1,自引:0,他引:1  
一小的甲龙,作为甲龙科中一新属新种,明星天池龙被记述。化石是1974年,新疆大学地质地理系的师生在新疆阜康县三工河地区作野外实习时采得,其产地的地层层位经新疆石油管理局东疆石油指挥部希龄核对为中侏罗世头河组。化石包括破的头骨碎片,五个颈椎,六个背椎,一个完整荐部(由七个维体组成),三个尾椎,和许多膜质的甲胄,甲板,以及一些四肢骨。标本编号:V.10614.新属新种的特征是:一个小的,原始的,体长约  相似文献   

11.
A longirostrine choristoderan reptile is described from the Early Cretaceous Tetori Group on the basis of an associated specimen from the Kuwajima Formation, Ishikawa Prefecture. This is the first report of Neochoristodera from Japan. However, the brevirostrine Monjurosuchus has already been reported from the same deposit, and the long-necked Shokawa was recovered from the Okurodani Formation, which is a lateral equivalent of the Kuwajima Formation. This new material demonstrates that the three known choristoderan morphotypes (short-necked longirostrine, short-necked brevirostrine and long-necked brevirostrine) were all present in the Early Cretaceous deposits of the Tetori Group. Until now, the Jiufotang Formation of China was the only deposit where all three were known to have co-occurred.  相似文献   

12.
The initial stages of evolution of Diapsida (the large clade that includes not only snakes, lizards, crocodiles and birds, but also dinosaurs and numerous other extinct taxa) is clouded by an exceedingly poor Palaeozoic fossil record. Previous studies had indicated a 38 Myr gap between the first appearance of the oldest diapsid clade (Araeoscelidia), ca 304 million years ago (Ma), and that of its sister group in the Middle Permian (ca 266 Ma). Two new reptile skulls from the Richards Spur locality, Lower Permian of Oklahoma, represent a new diapsid reptile: Orovenator mayorum n. gen. et sp. A phylogenetic analysis identifies O. mayorum as the oldest and most basal member of the araeoscelidian sister group. As Richards Spur has recently been dated to 289 Ma, the new diapsid neatly spans the above gap by appearing 15 Myr after the origin of Diapsida. The presence of O. mayorum at Richards Spur, which records a diverse upland fauna, suggests that initial stages in the evolution of non-araeoscelidian diapsids may have been tied to upland environments. This hypothesis is consonant with the overall scant record for non-araeoscelidian diapsids during the Permian Period, when the well-known terrestrial vertebrate communities are preserved almost exclusively in lowland deltaic, flood plain and lacustrine sedimentary rocks.  相似文献   

13.
Abstract:  The marine reptile Endennasaurus from the Upper Triassic Zorzino Limestone of northern Italy is redescribed and reassessed. New details of the skull and postcranial skeleton are revealed, confirming the attribution of this genus to the diapsid reptile clade Thalattosauriformes. Phylogenetic analysis suggests that Endennasaurus was related to the European genus Askeptosaurus and the Chinese Anshunsaurus . Despite a rather conservative postcranial morphology, Endennasaurus clearly occupied a highly specialized dietary niche as it combined a slender tapering premaxillary rostrum with a complete absence of either marginal or palatal teeth.  相似文献   

14.
15.
The vertebrate skull evolved to protect the brain and sense organs, but with the appearance of jaws and associated forces there was a remarkable structural diversification. This suggests that the evolution of skull form may be linked to these forces, but an important area of debate is whether bone in the skull is minimised with respect to these forces, or whether skulls are mechanically "over-designed" and constrained by phylogeny and development. Mechanical analysis of diapsid reptile skulls could shed light on this longstanding debate. Compared to those of mammals, the skulls of many extant and extinct diapsids comprise an open framework of fenestrae (window-like openings) separated by bony struts (e.g., lizards, tuatara, dinosaurs and crocodiles), a cranial form thought to be strongly linked to feeding forces. We investigated this link by utilising the powerful engineering approach of multibody dynamics analysis to predict the physiological forces acting on the skull of the diapsid reptile Sphenodon. We then ran a series of structural finite element analyses to assess the correlation between bone strain and skull form. With comprehensive loading we found that the distribution of peak von Mises strains was particularly uniform throughout the skull, although specific regions were dominated by tensile strains while others were dominated by compressive strains. Our analyses suggest that the frame-like skulls of diapsid reptiles are probably optimally formed (mechanically ideal: sufficient strength with the minimal amount of bone) with respect to functional forces; they are efficient in terms of having minimal bone volume, minimal weight, and also minimal energy demands in maintenance.  相似文献   

16.
The gliding reptiles of the Upper Permian   总被引:1,自引:0,他引:1  
The skeleton of a long-ribbed reptile from the Upper Permian Marl Slate of north-east England is described. The animal is assigned to the genus Weigeltisaurus , previously recorded from the Kupferschiefer of West Germany. Long-ribbed reptiles from the Upper Permian of Madagascar are also considered. Daedalosaurus Carroll, 1978 is a junior synonym of Coelurosauravus Piveteau, 1926. The European and Madagascan genera can be accommodated within a single family Coelurosauravidae, Infraclass Eosuchia. The skull is diapsid with an incomplete lower temporal arcade. Comparison with the modern Draco and the Upper Triassic kuehneosaurids supports the conclusion that the coelurosauravids were effective gliders.  相似文献   

17.
The pectoral girdle and forelimb of the Late Triassic drepanosauromorph reptile Megalancosaurus are redescribed and their function reinterpreted. The whole skeleton of this diapsid is highly specialised for arboreal life, and also the peculiarities of the shoulder girdle and forelimb were interpreted as adaptations for a limb-based locomotion using gap-bridging to move from one support to another, as in chameleons. Re-examination of the pectoral girdle and forelimb revealed the presence of clavicles fused into a furcula-like structure, a saddle-shaped glenoid and a tight connection between the radius and ulna that strengthened the forearm but hindered pronation and supination movements at that joint. The new information plus a reconstruction of the pectoral and forelimb musculature suggests that the forelimb was also specialised for grasping and raking in addition to climbing and thus prey capture may have been an important function for the forelimb. The new functional interpretation fits well with the overall body architecture of Megalancosaurus’ skeleton, suggesting that this reptile was an ambush predator that may have assumed a stable tripodal position, secured by the hooked tail and hind limbs, freeing its forelimbs to catch prey by sudden extension of the arm and firm grasping with the pincer-like digits.  相似文献   

18.
Cosesaurus aviceps, a small, probable diapsid reptile from the Ladinian (Middle Triassic) of Montral-Alcover (prov. Tarragona, Spain), has been reported as an ancestor of the Neornites. The only known specimen of this taxon is likely an inmature individual. The allometric growth models have been introduced in the character analysis, to infer the features of the adult Cosesaurus. For the present analysis, only the features that can be ascertained without doubt have been retained. The characters have been classified as primitive and derived. Cosesaurus shares all the ten derived characters we have found with Prolacertiformes, especially with Macrocnemus. The sister-group Macrocnemus + Cosesaurus is characterized by the relatively elongated neck in respect both to the skull and trunk length, 7–8 cervical vertebrae with the centra relatively elongated, and a relatively narrow distal femur region.  相似文献   

19.
The holotype and only known specimen of the enigmatic small reptile Elachistosuchus huenei Janensch, 1949 from the Upper Triassic (Norian) Arnstadt Formation of Saxony-Anhalt (Germany) is redescribed using μCT scans of the material. This re-examination revealed new information on the morphology of this taxon, including previously unknown parts of the skeleton such as the palate, braincase, and shoulder girdle. Elachistosuchus is diagnosed especially by the presence of the posterolateral process of the frontal, the extension of the maxillary tooth row to the posterior margin of the orbit, the free posterior process of the jugal, and the notched anterior margin of the interclavicle. Phylogenetic analyses using two recently published character-taxon matrices recovered conflicting results for the phylogenetic position of Elachistosuchus–either as an archosauromorph, as a lepidosauromorph or as a more basal, non-saurian diapsid. These different placements highlight the need of a thorough revision of critical taxa and new character sets used for inferring neodiapsid relationships.  相似文献   

20.
The Middle Jurassic (Late Bathonian) Mammal Bed at Kirtlington, Oxfordshire, has yielded a rich assemblage of small vertebrates including mammals, frogs, salamanders and small reptiles. This paper describes the skull of a new diapsid reptile, Marmorelta oxoniensis, which was common within the fauna. The skull is gracile with large orbits and relatively long external nares. The frontals and parietals are single in the adult and almost separated on the roof of the skull by the postfrontals. The temporal region shows a mosaic of primitive and derived character states. The quadrate was firmly held to the skull by a large squamosal and a small, free, quadratojugal was retained. However, reduction of the anterior process of the quadratojugal and of the posterior process of the jugal left the lower temporal fenestra broadly open. Comparison with other diapsids leads to the conclusion that Marmoretta was a lepidosauromorph, most probably the sister taxon of Lepidosauria.  相似文献   

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