检索结果-南通市图书馆

SKULL MORPHOLOGY OF THE TRITYLODONT GENUS BIENOTHEROIDES OF SICHUAN

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Science in China,Ser.B 1984年第9期27卷 970-984页

作者：孙艾玲 institute of vertebrate Paleontology and Paleoanthropology Academia Sinica beijing

Bienotheroides wanhsienensis, known as the latest, representative of the tritylodont groupis characterized by the very short snout, largely covered maxilla and wide and flat basi-parasphenoid region, as compared with the others. In this paper the evolutionary changesof the osteology and venous system of the ear region from cynodonts to tritylodonts aredescribed and the growth and replacement of the postcanine teeth and the occlusion of thisanimal are discussed.

关键词： SKULL MORPHOLOGY OF THE TRITYLODONT GENUS BIENOTHEROIDES OF SICHUAN view

RELATIONSHIP BETWEEN EARTH'S ORBIT AND CLIMATIC CHANGES

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

chinese Science Bulletin 1980年第2期25卷 164-167页

作者：徐钦琦 institute of vertebrate {2. and palaeoanthropology Academia Sinica

The Milankovitch theory is one of the most important theories pertaining to the causes of ice ages. He thought that changes in the earth’s orbital geometry are the fundamental cause of the succession of Quaternary ic... 详细信息

关键词： Quaternary succession orbital dating hasbeen winter hemisphere horizon latitude separately

维普期刊数据库

Habitat selection by territorial male Ring-necked Pheasants: a synthetic analysis

在线全文

学校读者我要写书评

暂无评论

Habitat selection by territorial male Ring-necked Pheasants:...

2.rd International Ornithological Congress

作者： Ni Xijun Zheng Guangmei and Zhang Zhengwanginstitute of vertebrate Paleontology and Paleoanthropology,{2., beijing, 100044 Ministry Key Laboratory for Biodiversity Science and Ecological Engineering, College of Life sciences, beijing Normal University,beijing 100875, China

＜正＞ Recent research reveals that breeding male Ring-necked Pheasants （Phasianus colchicus） tend to select habitats that are mixed, establishing their territories where patches of several types of habitat meet. Traditional analyses dealt with such preferences by addressing selectivity for each habitat type separately. Our research emphasizes the need for a more interactive approach. Areas where several habitat patches mesh may be termed habitat complexes;pheasant selectivity for such complexes is the outcome of historic adaptation to modern

关键词： habitat complex. Ring-necked Pheasant habitat selectivity territory.

Phosphatized embryo fossils from the Cambrian explosion

在线全文

cnki会议

学校读者我要写书评

暂无评论

chinese Science Bulletin 1999年第9期44卷 842-845页

作者： YUE Zhao and Stefan Bengtsoninstitute of Geology , chinese {2. of Geological sciences , beijing 100037 , China Department of Palaeozoology , Swedish Museum of Natural History , Box 50007 , S-104 05 , Stockholm , Sweden institute of Geology Chinese Academy of Geulogical Sciences Beijing China Department of Palaeozoology Swedish Museun of Natuol History Stockholm Sweden

The earliest Cambrian (Meishucunian) phosphatized metazoan Olivooides from the Yangtze platform is represented by different developmental stages: from blastula through possible gastrula to tissue differentiation and finally to the hatched animals. The fossilization of embryos opens a new field in palaeontology-palaeoembryology. Embryological studies will be of importance for the understanding of ontogeny and phylogeny of metazoans from the Cambrian explosion.

关键词： embryo Early Cambrian Olivooides phosphatization.

维普期刊数据库

Late Oligocene-Miocene mid-latitude aridification and wind patterns in the Asian interior

在线全文

学校读者我要写书评

暂无评论

Late Oligocene-Miocene mid-latitude aridification and wind p...

中国科学院地质与地球物理研究所第十届(2.10年度)学术年会

作者： Jimin Sun~(1*),Jie Ye~2.Wenyu Wu~2.Xijun Ni~2.Shundong Bi~3,Zhenqing Zhang~1,Weiming Liu1,and Jin Meng~(4,2. 1 Key Laboratory of Cenozoic Geology and Environment,institute of Geology and Geophysics,chinese {2. of sciences, P.O.Box 982.,beijing 10002.,China 2.institute of vertebrate Paleontology and Paleoanthropology,chinese {2. of sciences,beijing 100044,China 3 Department of Biology,Indiana University of Pennsylvania,Indiana,Pennsylvania 15705,USA 4 American Museum of Natural History,New York,New York 1002.,USA

The Asian interior has the largest mid-latitude arid zone in the Northern Hemisphere,and so has become increasingly attractive for studying the initiation and the past extent of aridiflcation in this *** the enormousness of the Asian interior,it remains unclear how old and extensive the eolian deposits might have been,and what wind regimes have been responsible for the formation of the mid-latitude arid *** we report new eolian records of widespread Tertiary eolian deposits in a region far from the chinese Loess Plateau,the giant Junggar inland basin of northwestern *** results demonstrate that the earliest eolian deposition initiated ca.2. *** interpret that the Tertiary eolian dust in the Junggar Basin was transported by westerly winds,possibly from areas in Kazakhstan;the dust differs from the airborne dust transported by winter monsoon winds from the deserts of Mongolia and northern China that accumulated on the Loess *** results further reveal that the climate pattern,similar to that of the present,has prevailed at least since the latest Oligocene in Central Asia.

关键词：

GINKGOALEAN OVULATE ORGANS AND SEEDS ASSOCIATED WITH BAIERA FURCATA-TYPE LEAVES FROM THE MIDDLE JURASSIC OF QINGHAI PROVINCE,CHINA

在线全文

cnki会议

学校读者我要写书评

暂无评论

GINKGOALEAN OVULATE ORGANS AND SEEDS ASSOCIATED WITH BAIERA ...

侏罗系界限及地质事件国际学术研讨会

作者： Xiangwu WU Xiaoju YANG Zhiyan ZHOU Nanjing institute of Geology and palaeontology {2. academy of sciences 39 East beijing Road Nanjing 2.0008 China

＜正＞Ginkgoalean ovulate organs Yimaia, detached seeds and the associated Baiera-type leaves are described from a paper coal at the uppermost part of the Middle Jurassic Shimengou Formation in the northern border of ...

关键词：

New 40Ar/39Ar dating results from the Shanwang Basin,eastern China:Constraints on the age of the Shanwang Formation and associated biota

在线全文

cnki会议

学校读者我要写书评

暂无评论

New 40Ar/39Ar dating results from the Shanwang Basin,eastern...

中国科学院地质与地球物理研究所第11届（2.11年度）学术年会

作者： Huaiyu He~(a,*),Chenglong Deng~b,Yongxin Pan~a,Tao Deng~c,Zhaohua Luo~d,Jimin Sunb,Rixiang Zhu~b a Key Laboratory of the Earth’s Deep Interior,institute of Geology and Geophysics,chinese {2. of sciences,beijing 10002.,China b State Key Laboratory of Lithospheric Evolution,institute of Geology and Geophysics,chinese {2. of sciences,beijing 10002.,China c institute of vertebrate Paleontology and Paleoanthropology,chinese {2. of sciences,beijing 100044,China d China University of Geosciences,beijing 100083,China

The fluvio-lacustrine sequence of the Shanwang Basin,eastern China,preserves a rich and important terrestrial fossil fauna and flora;the exceptional preservation of these fossils reveals the dynamics of ancient mammalian ecosystems and plant ***,the timing of this sedimentary sequence has been the subject of debate for *** we contribute to this debate by presenting the detailed results of Ar/Ar analysis of the basalts above,below,and within the Shanwang *** dates place stringent constraints on the age of Shanwang Formation and associated ***/Ar ages obtained from basalts of the Niushan and Yaoshan Formations,which underlie and overlie the Shanwang Formation, are 2..0±2.5 Ma(2.,full external error) and 17.3±1.5 Ma(2.,full external error),respectively. The Ar/Ar age of the basalt in the Shanwang Formation is 17-18 *** the age constraints of the basalts of the Yaoshan and Shanwang Formations,the age of the Shanwang biota is estimated to be ca.17 Ma,late Burdigalian of the Early Miocene,indicating that the deposition of this fauna coincided with the onset of the mid-Miocene Climatic *** results provide new age constraints on the Shanwang mammal fauna,and independently support interpretations that this fauna can be assigned to chronozone MN4,and correlated with middle Orleanian of the European Land Mammal *** to late Hemingfordian of the North American Land Mammal *** diversity of the Shanwang Formation could reflect the global-scale mid-Miocene Climatic Optimum.

关键词： 40Ar/39Ar dating Geochronology Shanwang Formation Shanwang biota Miocene

BIOMECHANICAL PROPERTIES OF DINOSAUR EGGSHELLS (Ⅰ)─THE STRESS ANALYSIS OF THE DINOSAUR EGGSHELLS UNDER EXTERNAL PRESSURE

在线全文

cnki会议

学校读者我要写书评

暂无评论

古脊椎动物学报(中英文） 1994年第2期 104-106页

作者： Zhao Zikui(institute of vertebrate Paleontology and Paleoanthropology, Acadcmia Sinica)Ma Hezhong Yang Yongqi({2. University of Aeronautics and Astronautics)

Dinosaur are believed to be reproducing by eggs which hatch outside the body by the heat of the sun or by the environmental temperature. Therefore, the incubation period for eggs might be longer, like that of certain ... 详细信息

关键词： Dinosaur eggshell Thin shell External pressure Stress

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

神经元的迁移机制

生物化学与生物物理进展 1997年第6期24卷 499-504页

作者：于文斗张锦珠中国科学院生物物理研究所北京100101

在脊椎动物的脑发育过程中 ,未成熟的神经元在时间和空间上的精确迁移到达最后行使功能的目的地 ,是中枢神经系统发育的一个重要阶段 .最近的研究结果表明这一过程涉及到一系列分子事件 ,包括细胞表面分子的相互作用、离子通道的激活和... 详细信息

在脊椎动物的脑发育过程中 ,未成熟的神经元在时间和空间上的精确迁移到达最后行使功能的目的地 ,是中枢神经系统发育的一个重要阶段 .最近的研究结果表明这一过程涉及到一系列分子事件 ,包括细胞表面分子的相互作用、离子通道的激活和细胞骨架的作用等 .对这些事件的了解不但有助于了解神经元迁移的机制。

关键词：神经元神经胶质细胞迁移

维普期刊数据库