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1.
A new species of Gobiconodon from the Early Cretaceous in the Lujiatun locality of western Liaoning is erected based on an almost complete skull and lower jaw. It has a flatten skull roof, the lambdoidal crest is strongly curved forward, and the sagittal crest is short and low. There is a protuberance near the anterior base of the zygoma. The preservation of the upper teeth is very rare in all known Gobiconodon, and this provides important information for the study on the formula of Gobiconodon. The new species is the fifth primitive mammal unearthed from the Lujiatun locality, and is of great value for the study of the geological age of the stratigraphy at Lujiatun by primitive mammal material.  相似文献   

2.
Doklady Earth Sciences - Tooth marks preserved on a dentary fragment of eutriconodontan Gobiconodon borissiaki Trofimov, 1978 from the Early Cretaceous Zuun-Höövör locality in...  相似文献   

3.
New Tapejarid Pterosaur from Western Liaoning, China   总被引:6,自引:1,他引:5  
A new tapejarid pterosaur Huaxiapterus jii gen. et sp. nov. is erected based on a nearly complete skeleton with a skull. The skull morphology of Huaxiapterus jii gen. et sp. nov. appears transitional between the skulls of Sinopterus and Tapejara. The skull morphology (low crest) of Huaxiapterusjii indicates that Huaxiapterus is more closely related to Sinopterus than to Tapejara, which has a high crest. The relatively long and shallow skull of Sinopterus indicates that it is a primitive form. Huaxiapterus is more derived than Sinopterus but more primitive than Tapejara.  相似文献   

4.
A new specimen consisting of a complete skull and lower jaw was discovered from the Lujiatun bed of the Lower Cretaceous Yixian Formation in the Lujiatun site, Beipiao, western Liaoning Province. It represents an adult specimen of Hongshanosaurus houi. Comparative studies show that Hongshanosaurus is distinguishable from its sister taxon Psittacosaurus by having the preorbital portion about half of the basal skull length, and the elliptical external naris,orbit, and a lower temporal fenestra oriented caudodorsally.  相似文献   

5.
A new specimen of basal neoceratopsian dinosaur Liaoceratops yanzigouensis is described. The specimen comes from the Lujiatun Bed of the Lower Cretaceous Yixian Formation in Beipiao City of western Liaoning Province, and is represented by a very well preserved three-dimensional partial skull and mandible. It is also the smallest among the three specimens of L. yanzigouensis, and several features in the new specimen, such as the short preorbital length and the round rostroventral orbital rim, can be ontogenetically-related. The superb exposure of the palatal complex may be caused by the removing of its brain by a small predator in the contemporary Jehol Biota.  相似文献   

6.
报道了一件产自辽西北票地区早白垩世义县组陆家屯层中的燕子沟辽角龙(Liaoceratops yanzigouensis)化石标本。该标本保存了燕子沟辽角龙的一些典型特征:前颌齿3颗;较大的三角形的眶前窝,外颧骨不发育;前齿骨上翘呈钩状;下颌后腹缘的边棱脊发育,并在其后部发育瘤状结节。根据对化石的CT扫描和三维图像重建,笔者对燕子沟辽角龙吻骨的形态特征进行了补充,包括吻骨前缘呈龙骨脊状,后侧发育一棱柱状纵脊等。此外,首次对燕子沟辽角龙的头后骨骼进行了描述,其中,股骨第四转子的特征可能对基干新角龙类的分类有一定意义。  相似文献   

7.
<正>Recent discoveries of basal birds have greatly improved our understanding of early bird evolution,yet the evolution of several important features such as cranial kinesis and arboreality remain debated.A new sapeornithid bird,Shenshiornis primita gen.et sp.nov.,based on an articulated skeleton from the Early Cretaceous Jehol Group of western Liaoning,China,sheds new light on these issues.Shenshiornis possesses a skull as primitive as or even more primitive than that of Archaeopteryx and hind limbs modified for an improved arboreal capability.A cladistic analysis shows that:1) presence of a diapsid skull is a plesiomorphy of the Aves and a kinetic skull evolved incrementally later in avian evolution;and 2) cursorial capability significantly weakens at the base of the Pygostylia due to a change in locomotor system.  相似文献   

8.
A new species of Huaxiapterus: H. benxiensis sp. nov. is erected based on the new specimen. The diagnostic characters of Huaxiapterus benxiensis are well-developed premaxillary crest and parietal spine, the crest and spine parallel and extending posterodorsally, and a shallow groove present on the dorsal surface of the anterior portion of the mandibular symphysis. The different skull morphologies of Chinese tapejarid pterosaurs indicate that they are much more diverse than the previous thought.  相似文献   

9.
系统描述了采自贵州省兴义中三叠统竹杆坡组一件较完整的巨胫龙(Macrocnemus)属化石标本,补充和完善了M.fuyuanensis部分头骨及腕骨和跗骨特征。基于当前标本与欧洲的M.bassaniis和中国的M.fuyuanensis的比较,认为当前标本与M.fuyuanensis四肢骨骼大小及比例较为接近,但两者的胫骨与桡骨、尤其第4跖骨和第4掌骨之间的比例不同。鉴于当前标本较少,头骨保存不完整,且当前标本与M.fuyuanensis正模标本的产地相距不远,本文暂将其确定为后者的相似种。  相似文献   

10.
A new marine vertebrate assemblage from the Late Jurassic (late Kimmeridgian) at Krzy?anowice near I??a in the NE margin of the Holy Cross Mountains in Poland is described. This new locality is rich in fossils of coastal and pelagic reptiles. The most frequent fossils are plesiochelyid turtle shell fragments and pliosaurid skull bones and teeth. The Krzy?anowice vertebrate assemblage is similar to the Late Jurassic Boreal/Sub-Boreal localities of the Kimmeridge Clay in Great Britain and Svalbard Archipelago in the Arctic, in the presence of pliosaurids and long-necked plesiosaurids. However, plesiochelyid turtles and crocodylomorphs are similar to those from the Mediterranean/Sub-Mediterranean sites of the northern border of the Tethys Ocean, as, for example, in the Swiss Jura Mountains and Southern Germany. This unique composition of the Krzy?anowice vertebrate fauna demonstrates that, during the Late Jurassic this new locality was located in the transitional palaeobiogeographic line referred to in this paper as the “Matyja-Wierzbowski Line”. The new palaeobiogeographical reconstructions of Late Jurassic of Europe are based on the composition of the Krzy?anowice locality and other sites with similar turtle-pliosaurid faunas which formed a long-term, stable ecological sympatry in marine ecosystems of the European Archipelago.  相似文献   

11.
陈萌  罗哲西 《地质学报》2008,82(2):155-164
尖吻兽(Akidolestes)是新近在中国辽宁省下白垩统义县组地层发现的对齿兽动物,保存了非常完整的头后骨骼。其齿列特征表明它属于鼹兽超科(Spalacotheroidea)中的鼹兽科动物(Spalacotheriidae),该科是以臼齿齿尖呈对称三角形排列、上下臼齿反转咬合为特征的单系类群,是现生兽类(有袋类和有胎盘类)的近亲,拥有许多兽类骨骼的原始特征。尖吻兽区别于张和兽科的特征是具有更宽大的下颌冠状突和臼齿齿尖呈更小的锐角排列。对尖吻兽的骨骼解剖学和比较形态特征的研究,表明尖吻兽演化模式是一种  相似文献   

12.
A previously unknown and morphologically distinct pentadactyl mammal track was recovered from the Upper Cretaceous (Maastrichtian) Laramie Formation at the Fossil Trace site, a National Natural Landmark which is the type locality for Schadipes crypticus, the only named mammal track known from North America. The track is different, and larger than S. crypticus, and thus is evidence of a diversity of mammal trackmakers at this site. Although Cretaceous mammal tracks are very rare, preliminary indications are that those currently known are all morphologically distinct and therefore indicative of a global diversity of different trackmakers, as the body fossil record suggests. Lack of well-preserved mammal trackways with morphologically distinct manus and pes footprints hampers efforts to name diagnostic ichnotaxa.  相似文献   

13.
A new pterosaur Moganopterus zhuiana gen. et sp. nov. is erected based on a complete skull with lower jaws and anterior cervical vertebrae. It is characterized by much elongated upper and lower jaws with at least 62 total, long, curved teeth with sharp tips, a well developed parietal crest extending posterodorsally, forming an angle of 15 degrees with the ventral margin of the skull, the ratio of length to width of cervical vertebrae greater than 5:1. The skull length is 750 mm, and it is the largest toothed pterosaur found so far in the world. Based on this new pterosaur, the Boreopteridae can be divided into two subgroups: Boreopterinae sub-fam. nov. and Moganopterinae sub-fam. nov., which is also confirmed by the phylogenetic analysis.  相似文献   

14.
The basal dinocephalian clade Stenocybusidae was known from two incomplete specimens representing one generus,Stenocybus,from Dashankou fanua in Yumen,Gansu Province of China.The holotype of Stenocybus acidentatus is laterally compressed,making some characters unclear.Here we describe two new specimens of Stenocybus acidentatus from the same locality,an anterior portion of skull with articulated jaws,and a right dentary with nearly complete dentition.They show some detailed features on the morphology of the premaxilla,maxilla,nasal,external nares and dentary.The phylogenetic relationship between Stenocybus acidentatus and the relatively large Sinophoneus yumenensis is still difficult to determine,and needs more new complete material and further evidences.  相似文献   

15.
16.
A fossil-bearing locality near Padhri village, Dhok Pathan, 55 km away from the tehsil Dina, Jhelum District, in the Potwar Plateau, Middle Siwaliks, Punjab, northern Pakistan, is significantly rich in mammalian fossils. This site has provided an abundant mammalian fossil fauna of Late Miocene age from the Dhok Pathan Formation (Fm.). The recovered material belongs to four families: Equidae (horses), Rhinocerotidae (rhinos), Bovidae (cows), and Suidae (pigs). We discovered a new skull of hipparionine Hipparion theobaldi from this locality along with 22 specimens from the associated assemblage of fossil mammals. The recovered material includes seven other species: the aceratheriine Chilotherium intermedium, boselaphines Tragoportax punjabicus, Selenoportax vexillarius, Pachyportax latidens, the antelope Gazella lydekkeri and suinine Propotamochoerus hysudricus. The specimens are isolated teeth, fragments of maxilla, mandibles and horn cores. The Dhok Pathan Fm. is generally composed of claystone, siltstone and sandstone beds and, based on the mammalian fauna, the Padhri fossil locality is dated as Late Miocene. Thi99s formation was deposited in a subtropical paleoenvironment and the predominance of fossil bovids indicates extremely moist conditions with small but frequent standing water bodies.  相似文献   

17.
Abstract

Edenopteron, with a lower jaw some 48?cm long, and total length perhaps exceeding 3 m, is the largest Devonian lobe-fin known from semi-articulated remains. New material described from the type locality (Boyds Tower, south of Eden) includes three slightly smaller articulated skulls and jaws, and additional bones of the shoulder girdle. Another articulated skull roof, shoulder girdle and palate is described from a second locality (Hegarty Bay), about 10?km south of Boyds Tower. Both localities represent the upper part of the Worange Point Formation, of late Famennian age (uppermost Upper Devonian). The new morphological evidence supports a close relationship to the tristichopterids Mandageria and Cabonnichthys, from the slightly older (Frasnian, Upper Devonian) fossil fish assemblage at Canowindra, New South Wales. Features of the shoulder girdle (supracleithrum, anocleithrum) suggest that Edenopteron is more closely related to Mandageria than Cabonnichthys. Eight characters are used to define a tristichopterid subfamily Mandageriinae, to which Notorhizodon from the Middle Devonian of Antarctica is also referred. The Mandageriinae is endemic to East Gondwana (Australia–Antarctica). In combination with possibly the most primitive tristichopterid, Marsdenichthys from the Frasnian of Victoria, these distributions implicate East Gondwana as a likely place of origin for the entire group. This relates to the major but unresolved question of a possible Gondwana origin for all the land vertebrates (tetrapods).
  • An endemic Gondwanan sub-group (Mandageriinae) of the Devonian fishes closest to land animals (tetrapodomorph tristichopterids) is confirmed.

  • Retention of primitive features (e.g. accessory vomers) points to an earlier origin of the Mandageriinae in East Gondwana, consistent with the Victorian occurrence of another primitive tristichopterid (Marsdenichthys).

  • Edenopteron is confirmed from a second south coast fossil site, and new characters indicate its closest relative is Mandageria from Canowindra, NSW.

  • Congruent evidence of older Gondwanan occurrences in other groups (basal tetrapodomorphs, rhizodontids, canowindrids), and previously dismissed trace fossil evidence (Grampians trackways), implicate South China and East Gondwana as the likely place of origin for all land vertebrates.

  相似文献   

18.
A new species of tapejarid pterosaur, Huaxiapterus coroUatus sp. nov. is erected on the basis of a nearly complete skull and postcranial skeleton from the Lower Cretaceous Jiufotang Formation of Liaoning Province, China. Huaxiapterus coroUatus sp. nov. is characterized by a hatchet-shaped rectangular process on the premaxilla, whose short axis is perpendicular to the anterior margin of the premaxillae. Except for this process, other characters of the skull such as the breadth of the snout between the anterior margin of the nasoantorbital fenestra and the anterior margin of the premaxilla are similar to that of Huaxiapterus jii. Huaxiapterus and a second Chinese tapejarid, Sinopterus, share several unique cranial characters in common with Tapejara and these three genera appear to be more closely related to each other than to other azhdarchoids. The Chinese tapejarids (Sinopterus and Huaxiapterus) have relatively elongate skulls and weakly developed cranial crests and seem to be less derived than Tapejara, with its shorter, deeper skull and large cranial crest. Tupuxuarids (Tupuxuara and Thalassodromeus) have often been associated with tapejarids in the family Tapejaridae, but this relationship is controversial because some phylogenetic analyses have supported the pairing of tupuxuarids with Azhdarchidae. We propose that Tapejaridae be restricted to Tapejara, Sinopterus and Huaxiapterus.  相似文献   

19.
An incomplete skull (SMNS 12352) from the Norian (Late Triassic), found at the same locality (Pfaffenhofen, Germany) as Procompsognathus triassicus, has previously been attributed to either a theropod or a crocodylomorph. The specimen is partially embedded in matrix and, therefore, was CT scanned so that the concealed portion could be visualized and a 3D model could be printed by means of rapid prototyping. Mainly based on the separation between the nasal and the antorbital fossa, the skull likely pertains to an indeterminate basal crocodylomorph (non-Crocodyliformes), which is, however, distinct from Saltoposuchus connectens.  相似文献   

20.
We present a large, fragmentary skull and the humerus of a mosasaur (Squamata, Mosasauroidea) recovered from upper Maastrichtian beds of the López de Bertodano Formation in Marambio (=Seymour) Island, Antarctica. The material belongs to a large, adult individual with marked heterodonty as well as unusual humeral features. Different phylogenetic analyses returned the studied specimen within the Tylosaurinae, while the distinctive features of the skull and humerus allow distinguish it from the unique Antarctic known tylosaurine species, Taniwhasaurus antarcticus (Novas et al., 2002), as well as from other known Late Cretaceous mosasaurids from the Southern Hemisphere, thus, justifying the erection of a new taxon, Kaikaifilu hervei gen. et. sp. nov. The different dental types documented in the specimen studied have been previously recorded through isolated teeth from the same locality and were subsequently referred to several genera. This new find is relevant for assessing the previously known fragmentary records of Antarctic mosasaurids, suggesting that its local diversity could be more reduced than previously interpreted. The new material represents the youngest occurrence of tylosaurines in Antarctica.  相似文献   

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