共查询到19条相似文献，搜索用时 109 毫秒
1.
孔子鸟（Confuciusornis）是最早具有角质喙及尾综骨的原始鸟类化石，同时兼具明显原始和显著进步的特征，在研究鸟类的早期演化方面具有极为重要的意义。孔子鸟头骨为典型的原始双孔类型，其角质喙与其它鸟类的角质喙是在进化过程中分别独立获得的。孔子鸟具有肋骨钩状突，这很可能代表着一种原始性状。孔子鸟飞羽发达，但未发育小翼羽。孔子鸟与长城鸟（Changchengornis)构成一组姊妹群，反鸟类(Enantiornithes)与今鸟类（Ornithurae)变构成一组姊妹群，这两类群又互为姊妹群关系。在孔子鸟已命名的4个种中，川州种（C.chuanzhous)和孙氏种（C.sunae)是圣贤种（C.sanctus)的晚出同物异名，应予以废弃。孔子鸟主要适应陆地生活，具有较强的飞行能力，并能够从地面起飞。目前关于孔子鸟的地质时代仍存在着晚侏罗世与早白垩世之争，但大多数动物化石都证实了孔子鸟层为晚侏罗世的观点。 相似文献
2.
中国辽西早白垩世九佛堂组发现大量反鸟类。最近本文作者又在辽西朝阳大平房九佛堂组发现了一新始反鸟。根据一具有头骨的完整的始反鸟骨架,建立一新属种:棘鼻大平房鸟。新鸟与其它已知中生代鸟类不同,区别在于个体中小型,鼻骨上具有明显棘突,以及胸骨具有长和短两侧突。反鸟类是早期鸟类最繁盛的一个分支,分异性十分明显,新鸟的发现不但是鸟类史中惟一具鼻骨棘突的鸟类,而且又给早期鸟类的多样性提供了新材料。中国辽西九佛堂组一新的始反鸟@李莉$沈阳师范大学辽西中生代古生物研究所!110034
@段冶$沈阳师范大学辽西中生代古生物研究所!… 相似文献
3.
4.
中国早白垩世今鸟类甘肃鸟的蹼足化石 总被引：1，自引：0，他引：1
玉门甘肃鸟(Gansus yumenensis)是中国发现的第一只中生代鸟类化石.该化石产自甘肃西北部下沟组,时代与辽宁西部产热河生物群的早白垩世地层的时代大体相当.该鸟类趾节拉长,很短的爪具有较尖锐的屈肌结节,因而被认为是一种适应于水生生活的鸟类.玉门甘肃鸟的建立最初仅依据一件左足标本,直到最近又发现了少量可供进一步研究的新标本.本文描述了一件新的玉门甘肃鸟的完整后肢化石,标本在远端趾节之间显示出清晰的蹼的构造.这为玉门甘肃鸟具有发育足蹼的观点提供了最直接的证据.玉门甘肃鸟也成为世界上已知最古老的适应于水生生活环境的鸟类. 相似文献
5.
采自内蒙古上白垩统二连组的一件标本代表巨龙类的一个新属种。新属种的正型标本包括若干背椎、荐椎和尾椎,部分背肋和脉弧,以及腰带的大部。新属种的鉴定特征包括后部背椎椎弓外侧有一源自后关节突的脊,后部背椎有一板状结构连接椎体—椎体横突板和椎体—前关节突板,前部尾椎尾肋前伸,有两个凹坑,以及肠骨内侧有一源自耻骨柄的直立脊。新属种肠骨气腔化,这一特征在蜥脚类恐龙中非常罕见。新属种具有一套独特的原始和进步特征的组合。初步的特征分析显示巨龙形类具有非常复杂的特征分布。近期的巨龙形类化石发现,这一类群在其早期演化阶段在… 相似文献
6.
本文描述了产于中国辽宁凌源早白垩世九佛堂组地层的一件鸟类化石标本。该标本中等大小,具有许多原始今鸟型鸟类的共同衍征;同时该标本也具有一个区别与其他已知原始今鸟型鸟类的长吻:吻长超过整个头骨长的70%;前颌骨前端尖而下钩,向前超出下颌前端,下颌齿骨前端直,仅上颌骨和齿骨上具有牙齿,代表了原始今鸟型鸟类一个新的属种和一个新的生态类型,因此建立了一个今鸟型鸟类新属种——张氏觉华鸟(Juehuaornis zhangi gen.et sp.nov)。 相似文献
7.
鸟类栖息行为是鸟类重要的生活习性,与鸟类后肢骨骼的形态结构之间存在密切的适应演化关系,而中生代鸟类栖息行为的分析推断也是古鸟类学研究的热点。文中通过对大量现生鸟类的后肢骨骼系统进行形态学对比、统计学分析,分别以后肢3块骨骼的长度变化、跗跖骨远端跖骨滑车的特征差异、第Ⅲ趾趾节长度变化规律和第Ⅲ脚爪爪弧的弧度大小为研究对象,并与其对应的栖息行为分别进行分析判断,然后将判断特征和有效变量运用于中生代鸟类栖息行为的推理中。通过系统的分析研究,对中生代鸟类的栖息行为得出如下的推断:大量基干鸟类的栖息习性是以攀援为主,只有少数可以树栖生活,反鸟类的栖息习性十分接近树栖鸟类,今鸟类的栖息行为兼有树栖、地栖的习性。 相似文献
8.
中国发现世界上最原始的鸟类化石：华美金凤鸟（新属、新种） 总被引：3，自引：0，他引：3
始祖鸟的发现被认为是19世纪最重要的科学发现之一,迄今为止共发现了7枚保存骨骼、羽毛印痕的化石标本和1枚单根羽毛化石标本。由于始祖鸟既显示了明显的爬行动物的特征又保存了精美的羽毛,140多年来人们一直将其作为介于恐龙与鸟类之间的“中间环节”(“missing link”),但更倾向认为它是世界上最古老的鸟,或鸟类的始祖。由于始祖鸟化石稀少,加之地理分布十分局限,长期以来国际上一直围绕鸟类起源问题展开了激烈的争论,提出了各种各样的假说。直到20世纪90年代,在中国辽西晚中生代地层中发现了大量长羽毛的恐龙和原始鸟类化石,有力地支持了鸟类起源于小型兽脚类恐龙的学术观点,使赫 140多年前提出的“假说”成为当今国际科学界占主流地位的学说和理论,基本解决了长期困扰国际科学界的鸟类起源问题,遗憾的是,在过去的几年中,中国一直没有发现与德国始祖鸟十分接近或与德国始祖鸟处于同样进化水平的原始鸟类化石,这种缺憾使我们难以对鸟类定义问题进行深入的研究和探讨,2002年,笔者等在中国辽西早白垩世断层中发现了2种初鸟类化石,即中华神州鸟和东方吉祥鸟。通过比较解剖学研究和支序分析,这2种初鸟类要比始祖鸟略微进步一些,在研究鸟类的早期演化方面具有重要意义;但仍然难以对鸟类定义问题作进一步研究。本文首次报道了一件采自中国河北省丰宁县龙凤山桥头组的初鸟类化石——华美金凤鸟（新属、新种）(Jinfengopteryx elegans gen.et sp.nov),与其共生的化石有Lycoptera davidi,Peipiaosteus pani,yanosteus longidorsalis（鱼类）;Jibeinia luanhera,Protopteryx fengningensis(鸟类）;Ephemeropsis trisetalis(昆虫）及少量植物。支序分析表明,华美金凤鸟处于初鸟类谱系树的基部,比始祖鸟略微原始,与后者为姊妹群关系。奔龙等兽脚类恐龙是它们的外类群。金凤鸟、始祖鸟是中华神州鸟等原始鸟类的外类群。这说明华美金凤鸟处在恐龙向鸟类演化过程中一个非常关键的位置,是世界上迄今所发现的最原始的初鸟类。华美金凤鸟的发现在研究鸟类起源、恐龙-鸟类的系统关系等方面具有重要的科学意义。 相似文献
9.
本文首次报道了鄯善地区中侏罗统齐古组产出一新的、原地保存的巨型蜥脚类恐龙—鄯善新疆巨龙( Xinjiangtitan shanshanesis gen. et sp. nov. ) 。其特征为: 倒第2 节颈椎在腹侧后1 /4 处向后发育一条棱嵴,并在后关节面下形成一小的半圆形突; 最后两节颈椎很长( 其长度之和为股骨、胫骨长度之和的63%) ; 第1 荐肋不参与构成荐椎轭; 股骨非常粗壮( 远端最大宽度为股骨长度的33%) 。支序分析显示新疆巨龙( 新属) 与马龙溪龙互成姊妹群,无疑为马门溪龙科中的一个新的分类群。但新疆巨龙( 新属) 还具有一些更接近于梁龙类的特征,包括发育明显的栖肌突、较短的后肢和股骨第4 转子位于股骨后侧内缘等。新疆巨龙( 新属) 的体长推算为30 ～ 32 m。 相似文献
10.
根据安徽省宁国县胡乐地区的反称笔石属（Anisograptus）标本,参照国内外Anisograptus的25种及亚种的资料,发现反称笔石类的形态变化具有原始枝末端分支推迟和笔石枝密度缩减的特点,其中,部分种及亚种的胞管密度较大,与其他种类区别明显。因此,笔者等选择原始枝长度、分支密度、胞管密度为分类依据,将Anisograptus划分为如下5个种类：A．matanensis Ruedemann,A．ruedemanni Bulman,A．tetragraptoides Bulman,A．compactus Cooper和A．delicatulus Cooper。 相似文献
11.
A new Early Cretaceous enantiornithine bird from Liaoning Province of northeastern China, Shengjingornis yangi, gen. et sp. nov., is reported. This new bird possesses the following unique combination of features: a long rostrum, with some teeth in the front; short nasal; slender jugal; Y-shaped furcula, with expanded distal end of the hypocleidum; cake-like sternum, with a low and caudally distributed keel; strut-like and caudally concave coracoid. The derived features of the scapula and the wings suggest a powerful flapping flight capability. 相似文献
12.
新反鸟化石（Gracilornis jiufotangensis gen. et sp. nov.）产于辽宁省朝阳地区早白垩世九佛堂组。根据该反鸟的骨骼细弱、肢骨关节发达、胸骨与躯干相比较小（胸骨宽与躯干长比率约为0.11;胸骨长与躯干长比率约为0.13）等不同于其他已知反鸟的特征,建立一新属种,归于华夏鸟科（Cathayornithidae）。 相似文献
13.
WANG Xuri Jingmai K. O’Connor ZHAO Bo Luis M. Chiappe Gao Chunling Cheng Xiaodong 《《地质学报》英文版》2010,84(2):247-256
<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
14.
A New Enantiornitine Bird with Four Long Rectrices from the Early Cretaceous of Northern Hebei, China 总被引：3，自引：0，他引：3 
下载免费PDF全文
下载免费PDF全文 ZHENG Xiaoting ZHANG Zihui HOU Lianhai 《《地质学报》英文版》2007,81(5):703-708
Paraprotopteryx gracilis, a new enantiornithine bird from the Early Cretaceous Yixian Formation in Fengning, northern Hebei Province is erected, based on the following characters： Yshaped furcula with a long hypocleidum and a much narrow interclavicular angle, and the morphology of the sternum are different from other enantiornithines. Additionally, alular digit bearing the biggest manual claw extends distally to the distal end of the major metacarpal; the minor metacarpal is slender than the major metacarpal. Carpometacarpus only fused proximally; astragalus and calcaneum partially fused to one another but unfused to the tibia. This is the first record of Mesozoic birds in having four long rectrices, which may represent morphologically a secondary sexual character, an intermediate stage from elongated scale to branched feather, and possess functional advantage in supplementing the lifting surface to compensate the unskilled flight. 相似文献
15.
Enantiornithine Bird with Diapsidian Skull and Its Dental Development in the Early Cretaceous in Liaoning, China 总被引：7，自引：5，他引：2
GONG Enpu HOU Lianhai WANG Lixia Department of Geology Northeastern University Shenyang Liaoning Institute of Vertebrate Paleontology Paleoanthropology Chinese Academy of Sciences Beijing Liaoning Department of Land Resources Shenyang Liaoning 《《地质学报》英文版》2004,78(1):1-7
A Iarge number of enantiornithine birds are discovered from the Early Cretaceous Jiufutang Formation in western Liaoning, China. They are all small-sized birds with a few small teeth. The enantiornithine bird from the Jiufutang Formation in the Shangheshou area, Chaoyang, Liaoning Province reported in this paper is the largest individual known in all enantiornithine birds of the Early Cretaceous. However, its teeth possess a feature of pseudoheterodont. Some different development stages of the new teeth substitute the earlier stages and the stages of development are preserved in this specimen. This development pattern is similar to that of Archaeopteryx and alligator but not dinosaur. A well-developed postorbital was also preserved in the skull, which was a diapsidian skull like that of Confuciusornis. Additionally, the distinctive preservation of its prefrontal distinguishes it from other enantiornithine birds of the Early Cretaceous. 相似文献
16.
We report on a new enantiornithine bird, Dunhuangia cuii, gen. et sp. nov., from the Lower Cretaceous Xiagou Formation of the Changma Basin, northwestern China. Although the material is incomplete, Dunhuangia cuii preserves unique coracoidal and sternal morphologies that distinguish it from other known enantiornithines; this specimen represents only the second enantiornithine reported from the Changma Basin that is diagnostic at the species level. This study enriches our understanding of the enantiornithine component of this ornithuromorph-dominated, Early Cretaceous avifauna. 相似文献
17.
海龙类前肢化石标本(YIGM SPC V 0832-2)采自于云南省罗平县新寨一带中三叠统安尼阶(Pelsonian亚阶)关岭组二段顶部.其不仅为海龙类在罗平生物群中的首次发现, 而且为长颈型海龙的最早记录.该海龙类新材料虽然保存不全, 但是仍具有一些独特的特征: 桡骨远端两侧边缘平行; 尺骨远端扩展; 11个硬骨化腕骨; 第三掌骨近端内侧缘发育横突; 指式为2-3-4-4-4(?).虽然上述特征尚不足以建立一海龙类新属种, 但是仍然反映了部分海龙类单元在向海洋适应辐射的过程保留有原始爬行类的特征.这些原始特征暗示着部分海龙类可能以营陆生生活为主. 相似文献
18.
Burmese amber has recently provided some detailed glimpses of plumage, soft tissues, and osteology of juvenile enantiornithine birds, but these insights have been restricted to isolated wing apices. Here we describe nearly half of a hatchling individual, based on osteological and soft tissue data obtained from the skull, neck, feet, and wing, and identified as a member of the extinct avian clade Enantiornithes. Preserved soft tissue provides the unique opportunity to observe the external opening of the ear, the eyelid, and fine details of tarsal scutellation. The new amber specimen yields the most complete view of hatchling plumage and integument yet to be recovered from the Cretaceous, including details of pterylosis, feather microstructure, and pigmentation patterns. The hatchling was encapsulated during the earliest stages of its feather production, providing a point for comparisons to other forms of body fossils, as well as isolated feathers found in Cretaceous ambers. The plumage preserves an unusual combination of precocial and altricial features unlike any living hatchling bird, having functional remiges combined with sparse body feathers. Unusual feather morphotypes on the legs, feet, and tail suggest that first generation feathers in the Enantiornithes may have been much more like contour feathers than the natal down observed in many modern birds. However, these regions also preserve filamentous feathers that appear comparable to the protofeathers observed in more primitive theropods. Overall, the new specimen brings a new level of detail to our understanding of the anatomy of the juvenile stages of the most species-rich clade of pre-modern birds and contributes to mounting data that enantiornithine development drastically differed from that of Neornithes. 相似文献
19.
A New Species of Cathayornis from the Lower Cretaceous of Inner Mongolia, China and Its Stratigraphic Significance 总被引：2，自引：1，他引：1
LI Jianjun LI Zhiheng ZHANG Yuguang ZHOU Zhonghe BAI Zhiqiang ZHANG Lifu BA Tuya 《《地质学报》英文版》2008,82(6):1115-1123
An incomplete postcranial avian skeleton is described from the Lower Cretaceous Jingchuan Formation of Otog Banner of western Inner Mongolia and referred to a new species of Cathayornis, C. chabuensis sp. nov. This is the first report of a Cathayornis from outside Liaoning Province. The new discovery indicates that Cathayornis coexisted with Otogornis genghisi, and a more detailed comparison between these two enantiornithine genera shows that Otogornis represents a more primitive genus than Cathayornis. Our analyses further indicate that Cathayornis is an arboreal bird. The discovery of a Cathayornis from this region also confirms that the avian fossil-bearing Jingchuan Formation is comparable to the Jiufotang Formation of the upper Jehol Group in western Liaoning, and should be referred to the middle-late Early Cretaceous. 相似文献