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1.
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   
2.
Increases in biodiversity losses are a growing concern globally. In farm animals, related concerns about losses in genetic diversity have potentially increased with the emergence of breeding technologies that allow for faster genetic change in herds. Farmer and public acceptance of specific breeding practices can be influenced by a number of factors, including concerns about biodiversity and knowledge of biodiversity. The link between these factors and acceptance of new genetic technologies, if it exists, may help explain concerns about genetic technologies. This article examines the effect of attitudes and knowledge about biodiversity on the acceptance of genomic selection in livestock production using farmer and public survey data from Canada. Our results suggest that the link between biodiversity concerns and the acceptance of genomic selection is more robust for the public than for farmers. We also find that biodiversity knowledge and attitudes have opposite effects on acceptance of genomic selection.  相似文献   
3.
随着位置服务应用的兴起和移动智能终端的普及,高精度导航定位需求正在从孤立的区域延伸到无缝的全域,从专业群体走向大众用户。然而,实时、连续、完备的行人导航仍然面临着诸多挑战,如室外区域全球导航卫星系统(global navigation satellite system,GNSS)信号易受遮挡影响、室内环境Wi-Fi/低功耗蓝牙(bluetooth low energy,BLE)/地磁指纹库更新频繁、室外内过渡区域平滑切换困难等。此外,大众移动智能终端的定位传感器受成本与功耗限制,观测数据一般噪声较大且稳定性差。因此,提出设计了云-端协同的大众行人用户室内外无缝精密定位方案,突破了信标指纹库的众包采集与快速更新、智能手机多传感器信息融合的精密定位、室内外无缝切换等关键难题,研制了大众行人协同精密定位软件,通过综合利用位置服务平台提供的协同精密定位增强信息,以及智能手机终端获取的多源观测数据(GNSS、微型惯性测量单元(miniature inertial measurement unit,MIMU)、Wi-Fi、BLE、磁力计及气压计等),实现了大众用户室外精度优于1.5 m,室内精度1~3 m,并具备室内外平滑切换能力的导航定位服务,支撑了大众用户室内外无缝精密定位的需求。  相似文献   
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5.
We describe a new titanosaurian sauropod dinosaur, Borealosaurus wimani gen. et sp. nov., based on a distinctive mid-distal caudal vertebra from the early Late Cretaceous Sunjiawan Formation exposed in the Shuangmiao village of Beipiao in Liaoning, China. We provisionally refer an isolated tooth crown, a middle caudal vertebra, and a right humerus from the same locality and horizon to this taxon. Borealosaurus is distinguished from other sauropods in its possession of opisthocoelous mid-distal caudal vertebrae. The occurrence of opisthocoelous caudals in Borealosaurus and the Mongolian sauropod Opisthocoelicaudia raises the possibility that these taxa pertain to an as-yet unrecognized titanosaurian subclade endemic to the Cretaceous Asia.  相似文献   
6.
A new specimen of ankylosaurine dinosaur Crichtonpelta benxiensis is described. The new specimen is based on a nearly completely preserved skull from the same quarry as the holotype of the mid-Cretaceous Sunjiawan Formation in Shuangmiao, Beipiao City, Liaoning Province, China. Cladistic analysis incorporating new information from the new specimen resolves Crichtonpelta benxiensis is more advanced than basal members of Ankylosauridae (Kunbarrasaurus, Liaoningosaurus, Chuanqilong, Cedarpelta, Gobisaurus and Shamosaurus) and represents the first diverging branch of Ankylosaurinae. Comparisons to other mid-Cretaceous ankylosaurid-bearing dinosaur assemblages in northern China indicate a late Early Cretaceous to early Late Cretaceous age for the Shuangmiao dinosaur assemblage.  相似文献   
7.
中国甘肃省酒泉地区公婆泉盆地早白垩世恐龙化石   总被引:2,自引:0,他引:2  
尤海鲁  罗哲西 《地质学报》2008,82(1):139-144
中国甘肃省酒泉地区公婆泉盆地下白垩统新民堡群的恐龙化石主要由1992年中日丝绸之路恐龙考察计划和1997~2000年中美马鬃山恐龙考察计划发掘和研究。先后发现的恐龙包括兽脚类、蜥脚类、禽龙类和新角龙类等。这一新的公婆泉恐龙组合的主要特征是同时包含了在晚白垩世占主导地位的几类恐龙的基干分子,如戈壁巨龙(Gobititan)是巨龙型类的基干分子,马鬃龙(Equijubus)是鸭嘴龙型类的基干分子,而古角龙(Archaeoceratops)和黎明角龙(Auroraceratops)是新角龙类的基干分子。公婆泉恐龙组合的另一特征是其某些成员的体型较大,如似鸟龙类和镰刀龙类恐龙是同期同类中最大的。比较研究发现,公婆泉盆地新民堡群的恐龙和辽西热河群的恐龙关系密切,但前者的整体来说要比后者进步。考虑到公婆泉盆地新民堡群的时代(Albian)较辽西热河群(Hauterivian晚期-Aptian早期)晚,公婆泉恐龙组合似应代表中国北方早白垩纪鹦鹉嘴龙恐龙动物群进化过程中较进步的一个阶段。  相似文献   
8.
巨齿兰州龙(新属、新种)是发现于中国甘肃省兰州盆地早白垩世地层中的一新鸟脚类恐龙,其牙齿是世界上已知植食性恐龙中最大的。兰州龙下颌长1m,每侧有14个齿槽,而单个牙齿宽约4cm,这是已知恐龙中的首次报道。分支系统学分析发现巨齿兰州龙与非洲早白垩世Lurdusaurus arenatus关系密切。它们代表了鸟脚类恐龙进化中四足行走的笨重的一新支。兰州龙的发现也表明欧亚大陆与非洲在早白垩世具有较密切的联系。  相似文献   
9.
An almost complete juvenile dinosaur skull with lower jaw was discovered from the Early Cretaceous Yixian Formation in Beipiao, Liaoning Province, China. Here, the specimen is described and a cladistic analysis is performed in order to find its phylogenetic relationships. The result shows that this specimen represents a new genus of Psittacosauridae, Hongshanosaurus houi, gen. et sp. nov., and confirms the monophyletic status for Ceratopsia and Marginocephalia. However, Heterodontosaurus is found to be the sister taxon to Marginocephalia, rather than a basal Omithopoda.  相似文献   
10.
Abstract: The structure and orientation of the posterior extremity (tail club) of the caudal vertebrae of Mamenchisaurus hochuanensis Young and Chao, 1972 from the Upper Jurassic Shangshaximiao Formation has been analyzed to determine the tail club function using Finite Element Analysis. Of the four caudal vertebrae composing the tail club, the second largest (C"1") was probably the most proximal, and is fixed with the preceding sequence of the caudal vertebrae, whereas the smallest (C"4") is free and forms the termination of the tail club. Our analysis also suggests that the tail club is more efficient in lateral swinging rather than up-and-down motion, and that the best region for the tail club to impact is at the spine of the largest of the four caudals (C"2"), with a maximum load for impact at about 450 N. The tail club of Mamenchisaurus hochuanensis probably also had limitations as a defense weapon and was more possibly a sensory organ to improve nerve conduction velocity to enhance the capacity for sensory perception of its surroundings.  相似文献   
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