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1.
Xu X  Wang K  Zhang K  Ma Q  Xing L  Sullivan C  Hu D  Cheng S  Wang S 《Nature》2012,484(7392):92-95
Numerous feathered dinosaur specimens have recently been recovered from the Middle-Upper Jurassic and Lower Cretaceous deposits of northeastern China, but most of them represent small animals. Here we report the discovery of a gigantic new basal tyrannosauroid, Yutyrannus huali gen. et sp. nov., based on three nearly complete skeletons representing two distinct ontogenetic stages from the Lower Cretaceous Yixian Formation of Liaoning Province, China. Y. huali shares some features, particularly of the cranium, with derived tyrannosauroids, but is similar to other basal tyrannosauroids in possessing a three-fingered manus and a typical theropod pes. Morphometric analysis suggests that Y. huali differed from tyrannosaurids in its growth strategy. Most significantly, Y. huali bears long filamentous feathers, thus providing direct evidence for the presence of extensively feathered gigantic dinosaurs and offering new insights into early feather evolution.  相似文献   

2.
Xu X  Clark JM  Forster CA  Norell MA  Erickson GM  Eberth DA  Jia C  Zhao Q 《Nature》2006,439(7077):715-718
The tyrannosauroid fossil record is mainly restricted to Cretaceous sediments of Laurasia, although some very fragmentary Jurassic specimens have been referred to this group. Here we report a new basal tyrannosauroid, Guanlong wucaii gen. et sp. nov., from the lower Upper Jurassic of the Junggar Basin, northwestern China. G. wucaii is the oldest known tyrannosauroid and shows several unexpectedly primitive pelvic features. Nevertheless, the limbs of G. wucaii share several features with derived coelurosaurs, and it possesses features shared by other coelurosaurian clades. This unusual combination of character states provides an insight into the poorly known early radiation of the Coelurosauria. Notably, the presumed predatory Guanlong has a large, fragile and highly pneumatic cranial crest that is among the most elaborate known in any non-avian dinosaur and could be comparable to some classical exaggerated ornamental traits among vertebrates.  相似文献   

3.
A new iguanodontid,Jinzhousaurus yangi gen. et sp. nov., is erected based on the cranial and dental morphology of a specimen from the Yixian Formation of western Liaoning. Although a few primitive characteristics remain,Jinzhousaurus yangi display a number of characteristics similar to those seen in derived iguanodontids. Other interesting characteristics include the absence of antorbital fenestra and the frontal excluded from the participation in orbit, which are closer to the condition in hadrosaurids. The unusual combination of the characteristics provides important data for assessing morphological evolution toward hadrosaurs. The new discovery also represents the first reported large-sized dinosaur from Jehol fauna in western Liaoning, and increases the diversity of this famous fauna. Furthermore, the discovery of a derived iguanodontid from the Yixian Formation provides further evidence supporting a Cretaceous age of the Jehol fauna, which is consistent with an isotopic age.  相似文献   

4.
Göhlich UB  Chiappe LM 《Nature》2006,440(7082):329-332
Small Late Jurassic theropod dinosaurs are rare worldwide. In Europe these carnivorous dinosaurs are represented primarily by only two skeletons of Compsognathus, neither of which is well preserved. Here we describe a small new theropod dinosaur from the Late Jurassic period of Schamhaupten in southern Germany. Being exquisitely preserved and complete from the snout to the distal third of the tail, the new fossil is the best-preserved predatory, non-avian dinosaur in Europe. It possesses a suite of characters that support its identification as a basal coelurosaur. A cladistic analysis indicates that the new taxon is closer to maniraptorans than to tyrannosauroids, grouping it with taxa often considered to be compsognathids. Large portions of integument are preserved along its tail. The absence of feathers or feather-like structures in a fossil phylogenetically nested within feathered theropods indicates that the evolution of these integumentary structures might be more complex than previously thought.  相似文献   

5.
A fairly well-preserved specimen of a new primitive mammal, Repenomamus robustus gen. et sp. nov., has been described from the Yixian Formation (Lower Cretaceous), western Liaoning, China. This animal has several derived characteristics, such as well-developed den-tary/squamosal articulation, reduced number of tooth, differentiation of premolars and molars in postcanine teeth, presence of a dorsal process of the premaxilla that is not in contact with the nasal, closed medial wall of the orbit, and presence of fingerlike promontorium on the petrosal. It also retains some primitive reptile-like features. It is the most primitive taxon among the three mammals known from the Jehol Biota, and also represents the largest mammal of Mesozoic age over the world.  相似文献   

6.
A new species of Gobiconodon is found from the Yixian Formation of western Liaonlng, China. The new taxa,G zofiae sp. nov., has a confluent opening for branches Ⅱand Ⅲ of the trigeminal nerve on the anterior lamina of the petrosal. G zofiae sp. nov. is similar to Repenomamus in having an ossified Meckel‘s cartilage connecting the lower jaws and ear region. The new species, with enlarged I^1/I1, posteriorly located infraorbital foramen and four mental foramina,distinctly differs from the other species of Gobiconodon. The new material indicates that Gobiconodon has four, not five,upper molariforms. The presence of Gobiconodon in Jchol Biota makes it possible to correlate Jehol Biota with faunas in eastern Asia and North America, and suggests the age of the Yixian Formation to be Early Cretaceous.  相似文献   

7.
某膨润土钠化改性性能试验研究   总被引:5,自引:0,他引:5  
针对辽西膨润土大部分为钙基膨润土,使用效果差,经济附加值低等问题,采用理论分析和试验的方法,研究表明,该膨润土为钙基蒙脱石及二八面体属型,且具切脱(cheto)型特点;通过试验研究表明,钠化改形工艺不同,改性效果不同,干燥原矿钠化效果优于原矿直接钠化,指标接近于九台天然钠基土,其原因为干燥有利于膨润土充分水化,提高了碱水溶液的扩散速度及浸润改性嘭润土的效果.  相似文献   

8.
A long-tailed,seed-eating bird from the Early Cretaceous of China   总被引:23,自引:0,他引:23  
Zhou Z  Zhang F 《Nature》2002,418(6896):405-409
The lacustrine deposits of the Yixian and Jiufotang Formations in the Early Cretaceous Jehol Group in the western Liaoning area of northeast China are well known for preserving feathered dinosaurs, primitive birds and mammals. Here we report a large basal bird, Jeholornis prima gen. et sp. nov., from the Jiufotang Formation. This bird is distinctively different from other known birds of the Early Cretaceous period in retaining a long skeletal tail with unexpected elongated prezygopophyses and chevrons, resembling that of dromaeosaurids, providing a further link between birds and non-avian theropods. Despite its basal position in early avian evolution, the advanced features of the pectoral girdle and the carpal trochlea of the carpometacarpus of Jeholornis indicate the capability of powerful flight. The dozens of beautifully preserved ovules of unknown plant taxa in the stomach represents direct evidence for seed-eating adaptation in birds of the Mesozoic era.  相似文献   

9.
通过对火山岩、花岗闪长岩及金矿石的稀土元素组成的研究,探讨了稀土元素作为一种示踪剂在分析成矿物质来源中的应用.矿石的稀土元素组成与火山岩一致,与花岗闪长岩有明显的区别,表明二道沟矿床的成矿物质来源于火山岩系.  相似文献   

10.
本文从社会、经济、生态协调发展的角度构建了辽西地区水资源安全指标体系;运用模糊模式识别技术对其具有代表性的四个城市的水资源安全状况进行了研究.研究结果表明:朝阳、阜新市水资源处于较危机状态,锦州水资源处于中等安全状态,只有葫芦岛市水资源较安全,辽西地区水资源安全整体上来说级别较差.今后水资源开发的宏观对策是:以生态建设为前提,以加强管理促进全面节流为核心,以适当开源为补充.  相似文献   

11.
通过对辽西沿海经济区新型工业化进程的分析,提出通过实施城市群发展战略,加速辽西一体化建设;培育产业集群,以信息化带动工业化;采用高新技术和先进适用技术改造提升传统产业;加快资源型城市转型等对策,来提高辽西沿海经济区域市化水平。  相似文献   

12.
An exceptionally well-preserved fossil Kalligrammatid from the Jehol Biota   总被引:1,自引:0,他引:1  
A new species of Neuroptera, Sophogramma lii sp. nov. is described and illustrated in this paper. This new species is assigned to Sophogramma Ren of Kalligrammatidae, mainly based on its humeral recurrent veins, the basal cell present between posterior branch of media at base of wing, etc. The new species is distinguished from all other Sophogramma species on the difference of wing venation. This exceptionally well-preserved specimen is recovered from the Yixian Formation, Huangbanjigou, located near Beipiao City, in western Liaoning Province. The genus diagnosis has been emended based on new characters shown in this new species. Based on a summary of localities, distribution and geological ages of all genera and species of the Kalligrammatidae, we suggest that Kalligrammatids might have originated in Eastern Asia, especially in China. Function of the wing pigmentation is discussed briefly. Supported by National Natural Science Foundation of China (Grant Nos. 30430100 and 40872022), Beijing Natural Science Foundation Program (Grant No. 5082002), Scientific Research Key Program (Grant No. KZ200910028005) and PHR Project of of Beijing Municipal Commission of Education, Science-Technology Basic Condition Platform from the Ministry of Science and Technology of the People’s Republic of China (Grant No. 2005DKA21402)  相似文献   

13.
A Chinese triconodont mammal and mosaic evolution of the mammalian skeleton   总被引:16,自引:0,他引:16  
Ji Q  Luo ZX  Ji SA  Luo Z 《Nature》1999,398(6725):326-330
Here we describe a new triconodont mammal from the Late Jurassic/Early Cretaceous period of Liaoning, China. This new mammal is represented by the best-preserved skeleton known so far for triconodonts which form one of the earliest Mesozoic mammalian groups with high diversity. The postcranial skeleton of this new triconodont shows a mosaic of characters, including a primitive pelvic girdle and hindlimb but a very derived pectoral girdle that is closely comparable to those of derived therians. Given the basal position of this taxon in mammalian phylogeny, its derived pectoral girdle indicates that homoplasies (similarities resulting from independent evolution among unrelated lineages) are as common in the postcranial skeleton as they are in the skull and dentition in the evolution of Mesozoic mammals. Limb structures of the new triconodont indicate that it was probably a ground-dwelling animal.  相似文献   

14.
应用气相色谱法测定了秦岭南坡西段华山松籽油中脂肪酸组成,并与辽宁建平沙棘油脂肪酸组成进行了对比分析,二者所含主要脂肪酸成分的含量十分近似.结果表明,秦岭南坡西段华山松籽油具有与沙林油类似的营养保健价值及防癌抗癌作用.  相似文献   

15.
A well-preserved pterosaur with nearly complete skull is described from the Lower Cretaceous Yixian Formation at Sihetun in western Liaoning. It is characterized by a low and long crestless skull, slender and pointed teeth, long metacarpal, nearly equal length of metatarsals I–III and short pedal digit V. It is referred to a new genus and species of the family Pterodactylidae:Haopterus gracilis gen. et sp. nov. This is the first pterosaur with a nearly complete skull from the Jehol Biota; it also represents the first non-controversial fossil record of Pterodactylidae in Asia.Haopterus is more derived thanPterodactylus from the Late Jurassic Solnhofen in Germany. This discovery extends the distribution of the family Pterodactylidae from Europe and Africa to Asia and its latest occurrence from the Late Jurassic to the Early Cretaceous. The discovery ofHaopterus gracilis provides further evidence for the study of the origin and radiation of the Jehol Biota; it also sheds new light on the evolution and distribution of pterosaurs in the late Mesozoic.  相似文献   

16.
17.
We describe two new ornithurine birds from the Early Cretaceous Jiufotang Formation of western Liaoning, northeast China: Yanornis martini gen. et sp. nov. and Yixianornis grabaui gen. et sp. nov. They represent the best fossil record of ornithurine birds known from the Early Cretaceous. They are more advanced than the most primitive ornithurine Liaoningornis, and are more similar to the other two Chinese Early Cretaceous ornithurines Chaoyangia and Songlingornis. Compared with Confuciusornis, Liaoxiornis and Eoenantiornis from the same age, the two new birds show remarkable advanced characteristics and suggest the presence of powerful flight capability like modern birds. Compared with Yixianornis and Chaoyangia, Yanornis is larger, with a more elongated skull and relatively long wings. The new discoveries indicate that by the Early Cretaceous both enantiornithine and ornithurine birds had already radiated significantly. The flight structures of Yanornis and Yixianornis are hardly distinguishable from those of modern birds; however, both retain a few primitive traits such as teeth on the jaws, wing claws and pubic symphysis, which exclude them from being the most recent ancestor of all extant birds.  相似文献   

18.
A new species of the elaterid genus Cryptocoelus Dolin and Nel, 2002 from the Late Jurassic to Early Cretaceous Yixian Formation in the western Liaoning, China is described. Diagnosis of the genus is revised, and the systematic position of the genus is briefly discussed. Because the elaterids originated in the Early to Mid-Jurassic, this new material from the Late Jurassic-Early Cretaceous will enhance our understanding of the transition between ancient elaterids and extant ones, bridge the gap of cryptic relationships between the Mesozoic cupedids and elaterids, and expand our knowledge of their evolutionary history.  相似文献   

19.
在实地调研的基础上总结了辽宁省乡村旅游“一圈两带”式空间分异现状,深入分析了产生此状况的经济、资源、市场及政策原因,并对此空间特点下的乡村旅游空间发展模式提出建议:辽西地区的“核心-边缘”式空间结构;辽中地区的“圈层集聚”式空间结构以及辽东南地区“全域集群”式空间结构。  相似文献   

20.
A new species of the elaterid genus Cryptocoelus Dolin and Nel, 2002 from the Late Jurassic to Early Cretaceous Yixian Formation in the western Liaoning, China is described. Diagnosis of the genus is revised, and the systematic position of the genus is briefly discussed. Because the elaterids originated in the Early to Mid-Jurassic, this new material from the Late Jurassic-Early Cretaceous will enhance our understanding of the transition between ancient elaterids and extant ones, bridge the gap of cryptic relationships between the Mesozoic cupedids and elaterids, and expand our knowledge of their evolutionary history.  相似文献   

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