首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 140 毫秒
1.
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   

2.
Sapeornithidae is a basal pygostylian family of Early Cretaceous primitive birds, in which only one genus and species, Sapeornis chaoyangensis, was reported before. This paper deals with a new genus and species of this family, Didactylornis jii gen. et sp. nov., which was unearthed from the Early Cretaceous Jiufotang Formation in western Liaoning. According to our phylogenetic analyses, both Didactylornis gen. nov. and Sapeornis form a sister group, which is basal to the clade formed by Confuciusornis and all the more derived birds, and more closely related to the short-tailed pygostylian birds than to the long-tailed avialian birds. The early history of pygostylian birds is poorly documented except for the studies of Confuciusornis and Sapeornis. The discovery ofDidactylornisjii gen. et sp. nov. adds the new material for the study on the early evolution of birds.  相似文献   

3.
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   

4.
鲁西地区寒武纪原始真牙形石分类方案的探讨   总被引:2,自引:2,他引:2       下载免费PDF全文
武桂春姚建新  纪占胜 《地质学报》2004,78(3):289-295,i001
鲁西地区晚寒武世地层发育,产有数量丰富、分异度大的原始真牙形石分子,经笔者研究,建立了2新属、2新种及2未定种Camconodontus rotundatus geo et sp.nov.,Camconodontus sp.,Laiwunodus lateronodus gen et sp.nov.,Laiwunodus sp.;对Das ytodus属进行了补充修订,建立了1新种Dasytodus posteronodus sp.nov.。这些属种的建立丰富了对已有原始真牙形石概念的认识。基于内部构造的观察,对原始真牙形石及部分易混淆的副牙形石进行正确的分类。以此为基础,分析、总结了这些分子外部形态上的差异,选用的分类原则和标准是从一般到特殊、特征明显程度逐渐降低,划分出了三类原始真牙形石和一类副牙形石,这在很大程度上简化了早期真牙形石分类研究的复杂性,为早期真牙形石的深入研究奠定了基础。  相似文献   

5.
<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   

6.
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   

7.
Early Cretaceous elasmobranchs still are very insufficiently known despite all progress that has been accomplished in recent years. Here, a small elasmobranch assemblage is presented from the Valanginian of Austria that contributes significantly to a better understanding of early Cretaceous elasmobranch diversity. The new assemblage comprises two new carcharhiniform sharks, Altusmirus triquetrus gen. et sp. nov. and Fornicatus austriacus gen. et sp. nov., a new orectolobiform shark, Similiteroscyllium iniquus gen. et sp. nov., and a galeomorph shark tooth of uncertain affinities. The recent identification of Similiteroscyllium gen. nov. has shown that it has strong similarities with Ornatoscyllium rugasimulatum from the Lower Cretaceous of France. Significant differences of the tooth morphology of O. rugasimulatum and the type specimen O. freemani justify full reconsideration of the systematic position of O. rugasimulatum and require it to be reassigned to Similiteroscyllium gen. nov. described in this paper. The new assemblage described here, and those from the Valanginian of France and Poland comprising 30 additional taxa, indicates that Early Cretaceous elasmobranch diversity was significantly higher than previously assumed. Consequently, the supposed diversity decline of elasmobranchs across the Jurassic-Cretaceous boundary represents a collecting bias rather than a real pattern.  相似文献   

8.
Two new genera and species of Cretaceous webspinners (Embiodea) are described and figured, both preserved in amber from northern Myanmar. Atmetoclothoda orthotenes Engel and Huang, gen. et sp. nov., is the first fossil representative of the putatively primitive family Clothodidae, and is segregated into its own subfamily, Atmetoclothodinae Engel and Huang, subfam. nov., owing to its primitive retention of a distinct mentum, a quadrate submentum with straight borders, a postocciptal suture that meets the hypostomal sulcus at the posterior tentorial pit, and subgenae that do not meet medially (thus a ventral bridge or gula is lacking), completely symmetrical terminalia, and unsegmented cerci that apically bear a small inner lamellar projection. Litoclostes delicatus Engel and Huang, gen. et sp. nov., is the first definitive fossil of Oligotomidae (not including a subfossil species in Pleistocene copal and which is likely synonymous with an extant taxon), and differs from modern genera in a combination of head, tarsal, and terminalic morphology. The new fossil species double the known Cretaceous fossils and add a further two families to the Mesozoic record for the order.  相似文献   

9.
<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   

10.
The following new fossil trichopteran insects are described or revised from the Purbeck Limestone Group and Wealden Supergroup of southern England: Pteromixanum inviolatum gen. et sp. nov., P. ruderatum gen. et sp. nov., P. purbeckianum (Handlirsch) gen. et comb. nov. and P. poxwellense gen. et sp. nov. (Necrotauliidae);Purbimodus minor gen. et sp. nov., P. medius gen. et sp. nov., P. rasnitsyni gen. et sp. nov. and P. saxosus gen. et sp. nov. (Vitimotauliidae);Palaeoludus popovi gen. et sp. nov. (Dysoneuridae);Palaeotarsus desertus gen. et sp. nov. (Plectrotarsidae);Eucrunoecia ridicula gen. et sp. nov. (Lepidostomatidae);Palaeocentropus placidus gen. et sp. nov. (Calamoceratidae) and Helicophidae gen. et sp. incertae sedis. The general composition of the fauna is compared with Early Cretaceous faunas of Asia. The early appearance of several living families is noted.  相似文献   

11.
1 Introduction The Jiufotang Formation is one of the most fossil- productive Early Cretaceous deposits of China. It overlies the famous Yixian Formation from which many important taxa were found (Ji et al., 2004; Chang et al., 2003; Zhou et al., 2003). In addition to other vertebrates, pterosaurs, the first flying reptiles in Earth history, are also abundant in the Jiufotang Formation. At present, nine species belonging to five genera have been reported from the Jiufotang Formation. The…  相似文献   

12.
An almost complete skull, which was collected from the Upper Cretaceous of the Bayan Mandahu area in Inner Mongolia, China by the Sino-Canadian Dinosaur Project, is described and assigned to a new genus of protoceratopsid dinosaur, Magnirostris dodsoni gen. et sp. nov. This new taxon is distinguished from other protoceratopsids by the robust rostral bone and the existence of incipient orbital horn cores. The existence of an additional antorbital fenestra indicates a close relationship between Magnirostris and Bagaceratops.  相似文献   

13.
和凯里生物群一样,贵州寒武系杷榔动物群也含有丰富的棘皮动物始海百合化石,包括两个属种即俞氏贵州始海百合 GuizhoueocrinusyuiZhao,ParsleyetPeng,2007及殷氏原始球状始海百合(新属新种)Protogloboeocrinusyini(gen.etsp. nov.).其中新属种是近期在杷榔组分布区南部贵州麻江下司淑里村杷榔组上部发现的,是凯里组中球形球状始海百合(GloboeocrinusglobolusZhao, ParsleyetPeng,2008)的原始属种,两者均具有发育的吸盘、长的茎、近于球形或椭球形的萼及较长 的腕.但新属种茎呈倒长锥柱形,缝孔长卵形,腕枝数少,两者区别明显.Protogloboeocrinusyini(gen.etsp.nov.)的发现及研 究,不仅追溯到凯里组球形球状始海百合的原始属种,了解两者演化规律是茎变短,萼变球形,缝孔变为圆形,腕枝数量增加, 捕食能力增强.而且还增添了杷榔组始海百合的多样性及其分区性:杷榔组分布区北部仅见Guizhouocrinusyui,南部仅见 Protogloboeocrinusyini(gen.etsp.nov.)   相似文献   

14.
贵州台江早—中寒武世凯里组的宏观藻类化石   总被引:7,自引:0,他引:7  
杨瑞东  赵元龙 《地质论评》1999,45(3):282-290
本文描述了贵州寒武纪凯里组中的宏观藻类化石7属12种,其中有6个新属10个新种;Bosworthia simulans,B.gyges,Eolaminaria grandis gen。et sp.nov。,E.perelegans gen。et sp。nov.,F.vein gen.et sp.nov.,Kailiphyton simulans gen.et sp.nov.,Palaeospine  相似文献   

15.
Eight new genera and thirteen new species of lacewings (Neuroptera) are described from the Lower Cretaceous Wealden Supergroup, Weald Sub-basin: Principiala rudgwickensis sp. nov. (Ithonidae), Stenomylina medialis gen. et sp. nov., Protosmylina bifasciata gen. et sp. nov. (Osmylidae), Cretapsychops corami gen. et sp. nov., Micropsychops parallelus gen. et sp. nov., Valdipsychops logunovi gen. et sp. nov., V. brigidae gen. et sp. nov., V. maculosus gen. et sp. nov., V. proudlovei gen. et sp. nov., V. minimus gen. et sp. nov., Psychopsites rolandi gen. et sp. nov. (Psychopsidae), Actinophlebioides valdensis gen. et sp. nov. and Protohemerobius perexiguus gen. et sp. nov. (Neuroptera familia incertae sedis). Psychopsidae are shown to dominate the neuropteran fauna, while the presence of Brongniartiellidae has not been confirmed in the Wealden, due to previously thought representatives of this family being in fact psychopsids. This is the first fossil record of Ithonidae and Osmylidae in Britain. The range of Kalligrammatidae has been extended in the Cretaceous of Britain from the mid-Valanginian to early Barremian.  相似文献   

16.
内蒙古赤峰早白垩世昆虫化石的新发现   总被引:7,自引:0,他引:7  
任东  朱会忠  陆有泉 《地球学报》1995,16(4):432-439
本文首次描述了内蒙古自治区赤峰市早白垩世九佛堂组的鞘翅目和异翅目昆虫化石4属5种,其中3新属5新种。这些昆虫化石通过与国内、外相关类群的对比,为该区的地层划分、对比和地质时代的确定,提供了最新的依据。由古生态方面分析,该区为湖沼环境,水体充沛,为古黑龙江流域的一部分。文中里阿龙虱科、沼梭科和中生五节蝽科的材料在国内是首次报道。  相似文献   

17.
A new ctenochasmatoid pterosaur, Gladocephaloideus jingangshanensis gen. et sp. nov. from the Yixian Formation of western Laioning Province is erected based on a complete skull and partial postcranial skeleton. It is characterized by following features: about 50 total teeth with sharp tips; small nasoantorbital opening, occupying approximately 13% of the skull length; ratio of prenarial length to skull length approximately 0.63. The diagnoses of the Ctenochasmatoidea and Gallodactylidae are amended based on the new taxon. Gladocephaloideus jingangshanensis is the first gallodactylid pterosaur found in Asia. Its discovery not only provides much more osteological information about the Gallodactylidae but also indicates that the ctenochasmatoid pterosaurs were highly diverse in the Early Cretaceous. The filamentous structures preserved near the dorsal and posterior margins of the posterior portion of the skull and around the neck indicate that it had an epidermal covering and may have been a warm-blooded animal.  相似文献   

18.
The genus and species Yuyuanozoon magnificissimi gen. et sp. nov., a new fossil vetulicolian, is reported from the Early Cambrian Chengjiang Fauna in Yunnan of China. It has a bipartite body plan and five pairs of chain-formed gill sacs, showing the general characteristics of Ventulicolia. However, the exclusive "atrial cavity" and external gill observed indicate that the new form is different from those previously described as vetulicolians, probably representing a lineage developed within deuterostomes and more primitive than urochordates.  相似文献   

19.
A new genus with one new species and five new species of genus Amblomma of fossil ommatids are described and illustrated: Euryomma tylodes gen. et sp. nov., Amblomma cyclodonta sp. nov., Amblomma miniscula sp. nov., Amblomma porrecta sp. nov., Amblomma eumeura sp. nov., and Amblomma protensa sp. nov. All of them were collected from the Upper Jurassic or Lower Cretaceous Yixian Formation of western Liaoning, China. A key to the species of Amblomma is given. The wide epipleural space shows that Euryomma may be a primitive genus in Ommatidae. Many different species of Amblomma occurred within the same sedimentary horizon in this area could be environmental changes caused by frequent volcanic activities during the deposition of the Yixian Formation.  相似文献   

20.
2009年8月,在内蒙古大兴安岭地区扎鲁特旗陶海营子重新测制了上二叠统陶海营子组剖面。自下而上共发现3层叶肢介(包括2层李氏叶肢介类Leaid化石),经鉴定为单脊型与双脊型的新种类。在中国,二叠纪的李氏叶肢介类(Leaid)化石前人仅在甘肃肃南县上二叠统肃南组发现过,计2属3种[1],其后一直未见报道。这类化石在大兴安岭地区的发现,填补了该时期中国东部李氏叶肢介类(Leaid)分布的空白,为该时期地层的区域对比和时代确定提供了重要的化石证据,具有重要的地层意义。同时,为进一步探讨它们的分布、迁徙、古生态、生物地理区系等增加了实际材料,具有古地理和古构造学上的理论意义。  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号