东江鱼类区系研究     

叶富良  杨萍  宋蓓玲 《广东海洋大学学报》1991,(2)

根据1981—1983年的调查结果,记述东江125种鱼类,分隶干11目25科,其中纯淡水鱼类为111种,鲤科鱼类有63种,占鱼类总数的50.4％,构成东江鱼类的基础;并讨论了东江鱼类的地理分布、来源、区系组成和地理区划。  相似文献   

A statistical test on diversity changes of Early and Middle Permian fusulinacean fauna in South China     

SHI Yukun & YANG Xiangning Department of Earth Sciences  Nanjing University  Nanjing  China 《中国科学D辑(英文版)》2005,48(7)

Regional stratigraphic data of major fossil groups in the critical geologic periods could provide reliable materials not only for the studies of diversity changes in different biogeographic provinces,but also for the comparison of regional patterns in the major biotic events accumulated in a long history of investigation,the paleontologic and stratigraphic data of South China have made indispensable contributions to re-vealing the pattern of end-Permian extinction[1―3],analyzing the differenc…  相似文献   

贵州关岭动物群产出地层的地球化学特征及其对物源和沉积环境的指示意义   总被引：1，自引：0，他引：1       下载免费PDF全文

唐宾  郝维城  孙作玉 《古地理学报》2005,7(2):261-274

对贵州关岭晚三叠统法郎组瓦窑段底部的毛凹剖面系统地采集了105个岩石样品，测定了样品中的36种化学元素含量。作者对它们进行元素富集因子（EF）分析、R型聚类分析、R型因子分析、元素和氧化物的含量与Al2O3的含量比值以及δCe在剖面中垂向变化的分析，讨论了元素含量变化的制约因素、沉积物的来源、古海洋氧化还原条件的变化、关岭动物群的埋藏环境。结果表明：研究的5.2 ~17.7 m段剖面地层以陆源碎屑和生物碎屑混合沉积为主，沉积物来源于陆壳，而不是火山和热液的来源，其沉积的氧化还原条件多次反复变化；元素的含量变化主要受陆源物质、氧化还原条件、生物碎屑以及成岩作用控制；从元素地层学角度将所研究的剖面段从下到上可划分为4层，第1层至第4层元素对比值曲线呈现出平缓波动-频繁波动-平缓波动的周期性变化特征；该段偏还原的环境对海百合及海生爬行动物化石的保存和埋藏起了良好的作用。  相似文献   

Mammal fauna first found in alluvial-speleogenic formations of the late Neopleistocene and Holocene, northern Urals, locality Cheremukhovo-1     

T. V. Strukova  O. P. Bachura  A. V. Borodin  V. V. Stefanovskii 《Stratigraphy and Geological Correlation》2006,14(1):91-101

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The Mesozoic ostracod genus Arculicythere Grékoff: further evidence for the southern Gondwana seaway     

Sara Ballent  Robin Whatley   《Cretaceous Research》2006,27(6):728-734

This paper demonstrates that Arculicythere Grékoff is a widespread taxon in the uppermost Upper Jurassic and Lower Cretaceous of Gondwana. It occurs in Madagascar, India, Israel, South Africa, the Falklands Plateau, Argentina and Australia. The earliest record is from the Upper Tithonian of Madagascar but the most profuse occurrences are in the Albian, when the genus was very widespread around Gondwana. Its distribution seems to be associated with a major southern Gondwana seaway, and the genus provides additional proof of the existence of this corridor. Unlike another endemic gondwanine genus, Majungaella Grékoff, which ranged from earlier in the Jurassic but extended into the Neogene in the Antarctic, or Rostrocytheridea Dingle that survived into the Campanian of the Antarctic, Arculicythere seems to have become extinct in the Albian.  相似文献   

The nature of Mawsonites (Ediacara fauna)     

A.J. van Loon   《Gondwana Research》2008,14(1-2):175

Some representatives of the Ediacara fauna have been later re-interpreted as pseudofossils. This was recently also done for Mawsonites, which was re-interpreted as a sedimentary structure formed due to interaction of a sand volcano (or water-escape structure) and a biomat. This sedimentary genesis appears not to be tenable, as several physical processes should have been involved, none of which is known from modern times or the geological past. It is concluded that Mawsonites must be considered as a fossil, either an imprint or a true fossil. This interpretation may be tested on one or more fragments of the structure.  相似文献   

河北省白洋淀地区中全新世丽蚌动物群及其生态环境意义   总被引：2，自引：0，他引：2       下载免费PDF全文

郭书元  詹伟  王强 《古地理学报》2014,16(3):335-346

丽蚌动物群的分布受气候和地理环境控制,研究地层中的丽蚌动物群可以恢复当时的古环境。在河北省白洋淀地区全新统共发现13种珠蚌科(Unionidae)的化石,属 Lamprotula-Cuneopsis-Unio 组合,称为白洋淀丽蚌动物群。该动物群与长江中下游流域太湖、鄱阳湖、洞庭湖及其周围水域的现代丽蚌动物群和山东王因、河南西水坡中全新世丽蚌动物群相比,虽然分异度低,但其组合特征相似,同属东洋界中印亚界动物地理区,生活于亚热带湿热气候下的河湖环境中。推测白洋淀丽蚌动物群的生活时代应为中全新世早期,当时北亚热带和东洋界的北界应在白洋淀以北的京津-河套一带。  相似文献   

内蒙古锡林浩特二叠系哲斯组腕足动物群特征及其意义   总被引：1，自引：0，他引：1  

杨兵  张雄华  杨欣杰  夏浩东 《地质通报》2017,36(10):1683-1690

内蒙古锡林浩特克什克腾旗哈尔呼舒剖面哲斯组灰岩中发现了大量腕足化石,经鉴定计有22属42种,以长身贝亚目和石燕贝亚目为主,化石组合面貌具有典型的哲斯动物群特征。根据其与邻区的腕足生物地层对比,确定该腕足生物群时代为中二叠世Wordian期。哲斯动物群中凉水型分子共计10属26种,约占种级总量的61.9%,暖水型分子仅1种,约占种级总量的2.4%,体现了典型的凉水型动物群特征。古生物地理区划属于北方生物地理大区。此外,哲斯组碳酸盐岩中颗粒组合属于苔藓虫-棘皮动物-腕足动物组合,代表凉水沉积环境,也印证了哲斯动物群的凉水型特征。  相似文献   

Flying high: on the airborne dispersal of aquatic organisms as illustrated by the distribution histories of the gastropod genera Tryonia and Planorbarius     

Wesselingh  F.P.  Cadée  G.C.  Renema  W. 《Geologie en Mijnbouw》1999,78(2):165-174

The actual and fossil distribution patterns of the aquatic gastropod genera Tryonia and Planorbarius indicate that avian dispersal was an important dispersal mechanism in the geological past. Combining the distribution histories of these genera with ecological data on modern relatives provides insights into the process of dispersal of aquatic taxa in general. Avian dispersal of aquatic taxa is facilitated by a variety of factors, including mass occurrence in resting/foraging places of migrating birds, ways to attach to the birds and to overcome desiccation during flight, as well as easy reproduction from a single specimen when introduced into a new habitat. The uncertain taxonomical status of aquatic organisms, as well as biased preservation and sampling, provide serious drawbacks for understanding the importance of aerial dispersal.  相似文献   

青海湖地区环境变化对动物区系演变影响的探讨   总被引：6，自引：0，他引：6  

陈涛  任杰  王恒山  马世震  李幸福 《湖泊科学》1992,4(4):41-47

青海湖地区近百年来由于气候干暖化趋势增强,湖周植被、土地退化,人类经济活动加剧,湖区青藏高原动物成分的种类和数量减少,但蒙新及华北动物区系成分则有增加趋势,致使该区动物区系成分发生显著变化。从青海湖地区动物区系形成来看,决定动物区系演变的原因主要是气候、生物等生态因子的综合作用,人为因子影响仅在近30年来才日益突出。  相似文献