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1.
山西天镇晚白垩世——新恐龙动物君及其地层意义   总被引:1,自引:0,他引:1  
程政武  庞其清 《地球学报》1996,17(Z1):135-139
新发现的山西天镇恐龙动物群是以巨龙类(titanosaurids)和甲龙类(ankylosaurids)为代表,含有鸭嘴龙类及兽脚类化石,其中一具何存较完整的巨龙类骨架(已获骨骼近70%)包括3个甲龙头骨及其头后骨骼.该动物君化石相当丰富,经与蒙古、印度、老挝、加拿大、美国和阿根廷等国晚白垩世恐龙动物君的比较我,实属晚白垩世较为罕见的一新恐龙动物群。由于天镇恐龙动物群的发现不仅将原划归始新世的灰泉堡组的时代归属晚白垩世,而且对白垩系划分和探讨恐龙的分类、演化、迁徒、动物地理区及其绝灭等方面的研究均具有重要意义。  相似文献   

2.
对首次在吐哈盆地台北凹陷侏罗系发现的分布于不同剖面、不同层位中的动物遗迹化石进行了系统研究。主要分析了研究区内动物遗迹化石的特征 ,将之划分为六大类型 :( 1 )垂直居住迹 ;( 2 )垂直觅食迹 ;( 3 )“U”形管 ;( 4)潜穴系统 ;( 5)逃逸迹 ;( 6)停息迹。较详细地分析了各类型的形态特征和保存特点 ,简要分析了造迹生物的行为习性及环境意义。在此基础上 ,建立了本区动物遗迹化石的环境模式。同时指出 ,遗迹化石在陆相含油气盆地确实大量存在 ,并在储层研究中具广泛的实践意义。  相似文献   

3.
Abundant medusoid soft-bodied metazoan fossils have been found in the Sinian Xingmincun Formation(with an isotopic age of 650 Ma) at Qipanmo, Qidingshan and Yangtun of the Dalian-Jinzhou area, southern Liaoning Province; in addition, a number of macroscopic algal fossils have been discovered for the first time in the Getun Formation overlying the Xingmincun Formation. Medusoid fossils include 3 genera and 6 species(all of which are new). Judging from their biological characters, these medusoid fossils are considered to have an intimate affinity with the Ediacara fauna in the terminal Precambrian of Australia, as their characters are close to each other. The authors suggest that these medusoids and the Edicara fauna might be the products of the same period. The discovery of the medusoid fauna in the Xingmincun Formation marks an important event in the evolution of the terminal Precambrian organisms in China, and it is of major practical significance in the study of the Sinian System of China and the correlation of the Sinian strata of northern and southern China.  相似文献   

4.
Exceptionally preserved fossils,such as those from Cambrian Burgess Shale-type fossil-Lagerstatten are critical because of their unique contributions to knowledge of the phylogenetic radiation and palaeoecological expansion of metazoans during the Cambrian explosion.Critically,these deposits provide information that is usually unobtainable from shelly and skeletonized fossils alone.The Guanshan Biota(Cambrian Series 2,Stage 4)in the Yunnan Province of South China,has produced abundant and diverse,exquisitely preserved fossils that often retain soft tissues and organs.To date,most fossils from the Guanshan Biota have been collected from localities such as Gaoloufang and Gangtoucun,which have become inaccessible due to new urban expansions and constructions of residential buildings.Here we present the first report of soft bodied fossils from a new section at Kanfuqing,close to the Wulongqing village in Malong County,approximately 3 km east of the Wulongqing Formation stratotype section.Fossils retain soft morphology,and include brachiopods with delicate marginal setae,priapulids with well-preserved sclerites and vetulicolians with entire sections of body.In addition,this fauna includes rare occurrences of trilobites preserved with soft tissues replicated as pyrite pseudomorphs after weathering.This discovery represents an important palaeogeographical extension of soft-bodied fossils of the Guanshan fauna to the east of the Xiaojiang Fault(related to Tsinning tectonic movements ca.700 Ma).The fauna from the new Kanfuqing section is similar to that reported from the Wulongqing Formation west of the Xiaojiang Fault,and thus has significant implications for early Cambrian palaeogeography,faunal successions and palaeoenvironments of eastern Yunnan.  相似文献   

5.
自从20世纪60年代初在山东诸城发现第一具恐龙骨架“巨型山东龙”以来,一系列具有代表性的恐龙骨骼化石在诸城白垩纪地层中被发现,特别是埋藏于诸城晚白垩世地层中恐龙骨骼化石群,最为引人注目。目前研究发现了包括鸭嘴龙类、角龙类、暴龙类等在内的多种恐龙类型,为丰富我国东部白垩纪恐龙动物群的研究提供了新的宝贵材料。该文系统总结和归纳了近些年来在诸城晚白垩世地层中发现的恐龙骨骼化石及其所代表的恐龙动物群类型的研究成果,同时又提出了目前依然存在的一些亟待解决的关键问题和研究意义,有助于下一步更好的深入研究诸城晚白垩世恐龙动物群。  相似文献   

6.
清河镇动物群各类化石的地史分布   总被引:5,自引:1,他引:5  
张炯飞 《地质论评》1993,39(1):44-51
清河镇动物群分布于华北地台北缘。建立清河镇动物群时,认为清河镇动物群包括管状化石、壳瓣状化石、球状壳化石、针状化石和近骨状类化石五个类型,并认为清河镇动物群的时代与梅树村动物群的时代相当。本文通过对清河镇动物群各类化石的分布规律和对所产化石地层的地质年代学和地层学的研究,认为不宜把针状化石和壳瓣状化石归入清河镇动物群;近骨状化石分布局限,其地史分布难以确定;管状化石出现于中元古代,至震旦纪和寒武纪大量产出,延续到奥陶纪;球状壳化石出现于寒武纪早期,至奥陶纪仍有。  相似文献   

7.
贵州台江中寒武世凯里组中分枝状宏观藻类化石   总被引:6,自引:1,他引:6  
本文描述了贵州中寒武世凯里组中的分枝状宏观藻类化石5属7种,即:Marpolia spissa Walcott,Marpolia aequalis Walcott,Guizhouella ramulosa Yang(gen.et sp.nov.),Doushantuophyton lineare Chen,Thamnophton formosus Yang(gen.et sp.nov.),Eoulothrix fibrillata Ding,Eoulothrix flabellophyton Yang(sp.mov.)。根据大量的藻类与凯里生物群共生特征,从藻类的生态及生物群分布受到沉积韵律控制等特征分析,认为凯里生物群生活环境的水深应该在30-60m,而埋藏和保存环境的水深是150m左右。另外,将凯里生物群中的宏观藻类化石与震旦纪陡山沱期的藻类化石进行了比较,两者在以分枝状藻类占主要组成上是相似的,从这一方面来说,晚震旦世宏观藻类与寒武纪宏观藻类没有大的演变,但寒武纪宏观藻类以出现钙质珊瑚藻类、分枝更加复杂的类型和具有锯齿状叶状体、生殖托构造的藻类为特征。  相似文献   

8.
The Eifelian–Givetian (Middle Devonian) transition constituted an important paleoenvironmental event for the Malvinokaffric Realm in the Apucarana Sub-basin (Paraná Basin). This study highlights integration between taphonomy and sequence stratigraphy, and four depositional sequences are identified during the transition. In Sequence 1, the presence of a typical normal-sized Malvinokaffric fauna is recorded. In the transgressive systems tract (TST) of Sequence 2, no benthic fossils are present, and this is interpreted as a stratigraphic marker of an event of significant paleoenvironmental change (KA?ÁK Event). In Sequence 3, the TST has abundant bioclasts, which become rarer toward the top of the section, i.e., within the transgressive systems tract. The original habitat of this autochthonous to parautochthonous fauna was a low-energy environment between the fair weather wave base and the storm wave base of the Devonian epicontinental sea. In the highstand systems tract of this sequence, the presence of normal-sized Pennaia paulianna and lingulids demonstrates the return of more ambient conditions. Sequence 4 is of Carboniferous age. Its limit is a second-order sequence boundary recording a lowstand systems tract formed by a fluvial depositional system. The low diversity and the disappearance of taxa are not the result of a taphonomic bias, but reflect the post-KA?ÁK Event.  相似文献   

9.
The “upper pit” at the Lost Chicken placer gold mine in east central Alaska contains fossils that provide information on the flora and insect fauna of interior Alaska just before the onset of global cooling at 2.5 myr. Fossils come from sediments interbedded with the Lost Chicken tephra (dated at 2.9 ± 0.4 myr—early Late Pliocene) and portray the floodplain and valley of a small creek within a region dominated by a coniferous forest richer in genera and species than the present one. Climate was wetter and less continental, and there was probably little or no permafrost. At least one other Pliocene tephra (the Fortymile tephra) occurs at the site and is also associated with plant and insect fossils. Among these fossils are extinct plants and insects like those found at other Tertiary sites in northern Canada and Alaska. The Lost Chicken sequence is the same age as the Beaufort Formation on Meighen Island, more than 1000 km to the north. Like Lost Chicken, Meighen Island sediments contain fossils representing a diverse boreal environment. This shows that the latitudinal climate gradient during early Late Pliocene time was shallower than at present and the boreal forest had a far greater latitudinal span than now.  相似文献   

10.
在安徽巢湖177高地、无为白牡山等地中二叠统栖霞组顶部灰岩段和臭灰岩段发现大量遗迹化石Zoophycos cf.caudagalli。这些遗迹化石以系统觅食迹为主,指示水动力及波浪作用较弱、贫氧的深水沉积环境。在栖霞组的砾状灰岩中,发现部分Zoophycos穿插于灰岩砾石和基质之中,这揭示栖霞组石灰砾岩中的砾石并非成岩作用成因,而是碎屑流沉积形成,属于异地成因碳酸盐岩。综合巢湖地区栖霞组的地层和岩石地球化学特征以及Zoophycos的生活习性和分布特征,发现表明巢湖地区中二叠统栖霞组臭灰岩段和顶部灰岩段属于贫氧的碳酸盐台缘斜坡沉积。  相似文献   

11.
A first account of paleontological data from three Cenozoic on-shore basins in Northern Vietnam, i.e. the Na Duong, Cao Bang, and Hang Mon basins, reveals a rich fossil fauna and flora of supposed Oligocene age, offering a great potential for taxonomic, paleoenvironmental, and paleobiogeographic studies. Two excavation campaigns unearthed well-preserved fossil remains of mammals, crocodiles, at least six turtle species, some 20 fish taxa, some other 20 mollusc species, and different plant remains. The majority of these taxa are regarded as new to science. However, close affinities to modern faunas of northern Southeast Asia demonstrate the importance of these fossils for an evaluation of the biological history of this modern biodiversity hot spot. Moreover, the fossil assemblages may help to disentangle the intricate Cenozoic tectonic evolution of Southeast Asia by application of paleobiogeographic modelling. Finally, the discovery of complex paleo-food-webs and the presence of several taxa indicative of certain ecological conditions provide a solid base for autecologic, synecologic and paleoclimatic studies. The potential biostratigraphic value of the macrofauna has to be demonstrated yet, as evolutionary concepts for most of the respective groups have not been proposed to date.  相似文献   

12.
Mammoth fossils and other Pleistocene vertebrates from the Upper Missouri Basin, in the northern Plains and Rocky Mountains of the western interior of North America, have been dated to the late Pleistocene and are associated with Wisconsinan deposits. Mammoth remains have also been found in older stratigraphic contexts. For example, Mammuthus columbi and other fossils from the Doeden Locality are in pre-Wisconsinan terrace gravels along the Yellowstone River; the deposits are likely Illinoian or Sangamonian. Faunas that appear to be associated with the Wisconsinan interstadial, before the Last Glacial Maximum, are found in intermountain valleys and mountain settings (the Merrell Locality, Blacktail Cave, Natural Trap Cave) and on the Plains in both glaciated and unglaciated regions (Box Creek, Wibaux gravel pit). Localities containing faunas dated to the time interval from about the Last Glacial Maximum to the end of the Younger Dryas chronozone (late Wisconsinan) include the youngest fossil-bearing strata at Merrell, Blacktail Cave, Natural Trap Cave; deposits at Sheep Rock Spring, Indian Creek, MacHaffie, False Cougar Cave, Shield Trap Cave; and mammoths found at Sun River, Glendive, Colby, and the Deer Creek drainage.  相似文献   

13.
贵州台江早—中寒武世凯里组的宏观藻类化石   总被引:7,自引:0,他引:7  
杨瑞东  赵元龙 《地质论评》1999,45(3):282-290
本文描述了贵州寒武纪凯里组中的宏观藻类化石7属12种,其中有6个新属10个新种;Bosworthia simulans,B.gyges,Eolaminaria grandis gen。et sp.nov。,E.perelegans gen。et sp。nov.,F.vein gen.et sp.nov.,Kailiphyton simulans gen.et sp.nov.,Palaeospine  相似文献   

14.
贵州早寒武世早期黑色页岩中生物化石保存及生态学研究   总被引:4,自引:0,他引:4  
早寒武世早期黑色页岩中以前只发现少量的海绵骨针,但随着研究的深入,各类动物化石被发现。最近,贵州早寒武世早期黑色页岩中发现碳质和薄膜型化石,它们包括大量的简单线状遗迹、碳质膜状高肌虫、完整海绵动物、管虫、薄壳双壳动物、碳质膜状软舌螺以及一些圆形膜状化石等。通过对黑色页岩的粘土矿物定量和定性分析,结合地球化学特征,认为早寒武世早期小壳动物繁盛期之上有一个大型动物繁盛期,随后由于地壳拉张作用,大规模的海底热液和火山喷发作用的加强,海洋环境变成酸性环境,不利于生物生存,发生生物绝灭作用,随后海洋环境逐渐趋于碱性,大量的生物又开始繁盛。  相似文献   

15.
Sediments from the last interglacial (Eemian) in Jameson Land, East Greenland, and the Thule area, NW Greenland, have revealed a number of insect fragments of both arctic and more or less warmth‐demanding species. Altogether, the interglacial fauna of Coleoptera (beetles) indicates boreal conditions. Undoubtedly, a large fraction of the insect fauna succumbed when the mild Eemian climate cooled drastically during the last glacial stage. However, a group of hardy species now found far north into the High Arctic might be glacial survivors. It is, however, still puzzling why well‐adapted arctic beetle species such as Amara alpina and Isochnus arcticus did not survive the last glacial stage in Greenland. Two factors that have not been sufficiently considered when discussing survival contra extinction are the importance of microclimate and the number of sun‐hours during the Arctic summer. Even among the Coleoptera, which as a group fares quite badly in the Arctic, there might be survivors, at least among those found both during the interglacial and as fossils during the early Holocene. First of all, glacial survival applies to the seed bug Nysius groenlandicus, which was widespread during the Eemian, was found soon after the last deglaciation, and is now almost omnipresent in Greenland.  相似文献   

16.
James G. Gehling  Mary L. Droser   《Earth》2009,96(3):196-128
The Ediacaran Period takes its name from the fossils of the Ediacara biota, which represent the first appearance of large and diverse assemblages of organisms in the fossil record. Although the global record of these distinctive body fossils is now well known, a previously unrecognized megascopic organic record of textured organic surfaces (TOS) occurs in the Ediacara biota. However, TOS is also a feature over a wider range of paleoenvironmental settings, where body fossils are unknown, in Ediacaran siliciclastic successions that have been studied in Australia, Namibia and western North America.Paleoecological analysis of successive bedding planes of strata from the late Ediacaran Rawnsley Quartzite in the Flinders Ranges of South Australia, reveals that TOS represent the most common organic features in bedding-surface assemblages of the Ediacara biota. The TOS consist of preserved, patterned assemblages of textured organic mats, fibers and simple tubular body fossils. Complex Ediacara body fossils while striking for their distinctive body plans, and dominating some of the beds, are relatively minor components of combined overall surface area. Many elements of TOS have previously been miss-diagnosed as trace fossils, which are in practice limited to two or at most three morphotypes that indicate the presence of Bilateria. Although TOS represent a simpler grade of organismic construction than discrete and more complex Ediacara body fossils, they were preserved in a similar manner. Marked variability in all components of the biota between successive surfaces suggests that Ediacara ecologies fluctuated at short intervals despite an apparently consistent sedimentary regime.  相似文献   

17.
豫南南阳盆地西峡赵营村上白垩统高沟组含有较多的恐龙蛋化石,其中最为著名的是“路易贝贝”胚胎化石。对含化石地层中恐龙蛋的保存特征和古气候重建,可进一步认识白垩纪恐龙灭绝的古环境背景和原因。本文实测赵营村剖面厚约267.8 m,主要由下伏泥盆系南湾组(厚7.9 m)、上白垩统高沟组(厚259.9 m,未到顶)组成。通过地层沉积物结构构造观测和样品采集,在室内进行了元素、碳酸盐碳氧同位素组成、有机质饱和烃生标化合物等测试。结果表明,高沟组沉积物主要源于熊耳山岩浆岩的风化和短距离迁移,恐龙蛋化石主要保存于海拔200~800 m的山麓至平原过渡带的河漫滩环境,以原地埋藏为主。降雨量的变化造成河漫滩与河道频繁变化,从而导致恐龙在山麓与河漫滩之间来回迁栖。生物标志化合物分析表明,含恐龙蛋化石地层有机质主要来源于水生植物、菌藻类和陆生植物,但植被总体不发育。利用地层沉积岩Si/Al、CIA、Rb/Sr比值,以及δ13C、δ18O等环境指标对高沟组古气候重建,该时期发生了较为快速的旋回变化,经历了暖干—暖湿—干旱—暖湿—干旱的古气候演变过程,总体上呈逐渐干旱化的趋势。通过赵营村晚白垩世早期恐龙蛋化石的埋藏、以及地层的古环境重建,说明古气候、古环境状况可能是影响恐龙生存的主要因素,大量恐龙蛋不能完全孵化以及气候的干旱化导致植被恶化可能是恐龙逐渐消亡的原因。  相似文献   

18.
Ennadai Lake, in the forest-tundra ecotonal region of Keewatin, Northwest Territories, Canada, has been the subject of several paleoecological investigations (palynology, plant macrofossils, fossil soils). This study concerns Holocene insect fossils at Ennadai, a new approach in a region shown to be sensitive to climatic change. The Ennadai I site yielded 53 taxa, representing 13 families of Coleoptera and 7 families of other insects and arachnids, including abundant ants. These fossils range in age from about 6300 to 630 yr B.P. The Ennadai II site produced fossils of 58 taxa, including 13 beetle families and 15 families of other arthropods, ranging in age from 4700 to 870 yr B.P. The insect evidence suggests the presence of trees in the Ennadai region from 6000 to 2200 yr B.P. A conifer pollen decline from 4800 to 4500 yr B.P. at Ennadai has previously been interpreted as an opening up or retreat of forest in response to climatic cooling, but the insect fossils reveal the continued presence of trees during this interval. Both insect assemblages suggest trends of forest retreat and tundra expansion between about 2200 and 1500 yr B.P., presumably due to climatic cooling, with a return of woodland by about 1000 yr B.P.  相似文献   

19.
双河洞中大熊猫-剑齿象动物群化石的发现   总被引:1,自引:0,他引:1  
对贵州省境内的双河洞历次科考中发现的第四纪动物群化石进行初步研究和总结,认为目前对双河洞第四纪动物群研究尚处于起步阶段,化石的发现者都是洞穴科考专家,古生物知识相对欠缺且重视不够是洞穴化石研究进展缓慢的原因。为了加快双河洞第四纪动物群的研究进程,以今年中法联合科考过程中发现的大熊猫-剑齿象动物群化石为样本,采用ICP-MS铀系定年方法对这批大熊猫骨骼化石碳酸盐岩包裹物的年龄进行测试,结果表明该化石群化石距今6.75万年,初步判定此动物群可能生存于中更新世-晚更新世早期。这批哺乳动物化石及其地层信息将为贵州(尤其是黔北)第四纪的研究提供重要资料。   相似文献   

20.
In the Linxia Basin on the northeast margin of the Tibetan Plateau, the Cenozoic strata are very thick and well exposed. Abundant mammalian fossils are discovered in the deposits from the Late Oligocene to the Early Pleistocene. The Dzungariotherium fauna comes from the sandstones of the Jiaozigou Formation, including many representative Late Oligocene taxa. The Platybelodon fauna comes from the sandstones of the Dongxiang Formation and the conglomerates of the Laogou Formation, and its fossils are typical Middle Miocene forms, such as Hemicyon, Amphicyon, Platybelodon, Choerolophodon, Anchitherium, and Hispanotherium. The Hipparion fauna comes from the red clay of the Liushu and Hewangjia Formations, and its fossils can be distinctly divided into four levels, including three Late Miocene levels and one Early Pliocene level. In the Linxia Basin, the Hipparion fauna has the richest mammalian fossils. The Equus fauna comes from the Wucheng Loess, and it is slightly older than that of the classical Early Pl  相似文献   

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