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1.
贵州剑河革东镇八郎村南甲劳组中部钙质白云岩中新近发现的具有粗强放射状辐管的水母状化石和其下凯里组中具细辐管及同心环的拟轮盘水母(Pararotadiscus)有明显区别,属于伊尔东钵科(Eldoniidae)。其层位晚于中寒武世早期凯里生物群中拟轮盘水母(Pararotadiscus)层位1个化石带,属中寒武世中期,是该类化石在中国的最高层位,相当于北美布尔吉斯页岩生物群中Eldonia化石层位。  相似文献   

2.
湘掠兽是我国下始新统中新发现的一种对锥齿兽类,与北美早始新世怀俄明兽(Wyolestes)比较相近。依形态和共生动物群的分析,其时代可能是早始新世早期。从有关剖面观察和追溯,其层位大致相当于栗木坪组。根据我国地层规范的规定,原岭茶组一名应予放弃,建议仍使用栗木坪组一名,以示衡阳盆地含哺乳动物化石的层位。  相似文献   

3.
粤北丹霞盆地白垩系长坝组产介形类化石 15 属 50 种,笔者描述其中 15 属 47 种(包括 3 个新种)。长坝组介形类动物群可以划分两个化石组合:( 1 ) Mongolocypris-Cypridea-Darwinula 组合,分布长坝组二段,属种繁多, 组合特征明显,与松辽平原泉头组 - 姚家组、湖北贾店组、浙江兰溪组等的介形类面貌相似,可以大致对比,由于出现少量晚白垩世标志化石 Talicypridea 属和大个体的 Mongolocypris 属,反映它与晚白垩世介形类的关系更为密切,但又不同于晚白垩世中晚期的南雄群 Talicypridea 动物群,层位偏低,时代较早,属晚白垩世早期为宜,大致相当于赛诺曼期( Cenomanian );( 2 ) Cypridea-Altanicypris-Candona 组合,分布长坝组四段,其层位在长坝组二段之上,晚白垩世丹霞组之下,组合中富含类女星介科的 Altanicypris 属,许多属种出现在晚白垩世地层中,其时代属晚白垩世无疑,与土仑期( Turonian )大致相当。  相似文献   

4.
辽宁凌源及相邻内蒙古南部宁城地区义县组发现多个重要脊椎动物化石地点,通过岩 石地层、脊椎动物生物地层和同位素年代地层对比,建立了该地区义县组地层层序。凌源一宁 城地区义县组有 2个脊椎动物化石层位:下部道虎沟层含 Lycopteraer Ichthyofauna, Psittacosaurus Fauna和Confuciusornis Avifauna等3个动物群,可以与北票尖山沟层的四合 屯脊椎动物化石群对比,层位相当于义县组一、三段;上部大王杖子(大新房子)层含 Lycoptera Ichthyofauna和Liaoxiornis Avifauna等2个动物群,为义县组中部沉积,在四合屯地 区缺失。冀北丰宁四岔口-森吉图地区义县组脊椎动物化石层对应于凌源大王杖子层;滦平 大北沟组为义县组最下部沉积,其上覆的大店子组相当于宁城道虎沟层和北票四合屯义县组 一、三段。热河群义县组和九佛堂组发现3个连续的鸟类群;义县组下部Confuciusornis Avifauna、义县组中部Liaoxiornis Avifauna和九佛堂组Cathayornis-Chaoyangia Avifauna。义 县组和九佛堂组Lycoptera I  相似文献   

5.
寒武纪最早期层位中获得的离散骨片化石Halkieria和Microdictyon,已在较高层位的特异埋藏化石群中找到了它们的完整生物躯体,它为研究离散骨片化石的自然分类和生物亲缘提供了直接证据。本文通过寒武纪最早期钉状化石的形状、对称性、壳质成分、矿化特征的对比,提出了离散骨化石织金钉(Zhijinites)和拟织金钉(Parazhijinites)与澄江动物群中的怪诞虫(Hallucigenia  相似文献   

6.
陕西铜川中三叠世中蝎蛉科新化石属种(昆虫纲:长翅目)   总被引:6,自引:5,他引:1  
新的中蝎蛉科化石标本采自陕西铜川中三叠世铜川组下段上部灰绿色泥页岩中,划分为2属2种,其中有1新属2新种:Erdosia pectinata gen.et sp.nov.,Mesopanorpodexs shaanxiensis sp.nov.。这些种类系陕西昆虫群(属陕西生物群的一个化石门类)铜川昆虫组合的新成员。铜川组的时代相当于欧洲拉丁尼期(Ladinian Stage)。  相似文献   

7.
广西南丹巴平石炭系中间界线地层的有孔虫   总被引:9,自引:6,他引:3  
南丹巴平地区石炭系中间界线地层(相当于苏联上谢尔普霍夫亚阶)中含有丰富的有孔虫化石。本文自下而上建立了三个有孔虫化石组合。这些组合可与苏联、北美及日本等地区同期的有孔虫化石层(带)对比。 本文采用二分石炭系的方案,以有孔虫Globivalvulina moderata开始出现的层位作为上石炭统底界的标志。将石炭系中间界线划在有孔虫化石组合Ⅱ和组合Ⅲ之间。大部分具下石炭统面貌特征的有孔虫分子在这个界线附近消失。 在巴平剖面,有孔虫Globivalvulina moderata开始出现的层位较牙形刺Declinognathodus noduliferus开始出现的层位略低。分别以这两个种的开始出现来确定石炭系中间界线虽有差异,但相差不大。  相似文献   

8.
记述产自西藏南部仲巴县的一个中国目前所知最年轻的菊石群,含2科4属6种,其中4新种。据菊石群面貌和它们所产出的层位可以划分出上、下两个组组合带:上部Pachydiscus cf.hidakaensis-Libycoeras zhongbaense组合带;下部Manambolites cujiaangdingensis-M.pivaeteaui组合带。 石的曲贝亚组的下段和上段的中、下部(82F50及其以下层位)为晚Campanian期,上段上部(即8252及其以上层位)为早Maastrichtian期。  相似文献   

9.
中国陕西中三叠世中蝎蛉科三新属新种(昆虫纲,长翅目)   总被引:1,自引:1,他引:0  
记述中蝎蛉科Mesopanorpodidae 4属4种,其中包括3新属4新种:Longifurcula hejiafangensi gen.et sp.nov,Ladinochorista lata gen.et sp.nov.,Allochorista erdosensis gen.et sp.nov.,Itaphlebia tongchuanensis sp.nov..化石标本采自陕西铜川中三叠统铜川组下段上部的灰绿色泥岩和页岩.这些新属、种系陕西昆虫群铜川昆虫组合的新成员(属陕西动物群、陕西生物群的一个类别).根据前人的植物、孢子、双壳、叶肢介、介形虫、昆虫化石等的研究结果,铜川组的时代划归中三叠世,相当于欧洲中三叠世拉丁尼期(Ladinian stage).  相似文献   

10.
记黑龙江畔一鸭嘴龙足印化石   总被引:4,自引:0,他引:4  
2002年9月,来自七个国家的地层古生物学者,在中国吉林省长春市吉林大学举行了“黑龙江流域白垩纪生物群及K/T界线国际学术研讨会”。会议之后学者们对黑龙江沿岸中新生界地层进行了实地踏勘,在踏勘的过程中在嘉荫县永安村之东南1.2km的黑龙江岸边发现了一滚石板,其上保存一较完整的大型恐龙足印。足印印迹在厚层钙质胶结的粗砂岩上,经查对化石产出岩层为嘉荫群永安村组(Sun et a1.,2003)。化石是一大型的三趾的足印(tridactyl),三趾短粗,中趾呈U型,趾间有蹼的痕迹,造印者应是一只鸭嘴龙(Thulbom,1990)。黑龙江省嘉荫县是我国第一只命名的恐龙——黑龙江满洲龙(Mandschurosaurus amurensis)化石的产出地,化石产自嘉荫群渔亮子组(Riabinin,1925,1930;Dong,1992)。本文记述的标本是嘉荫群中发现的第一件足印化石,也是我国鸭嘴龙类足印化石的首次记录(甄朔南等,1996)。  相似文献   

11.
As late cretaceous and Paleocene was an important stage in the evolution of angiosperms, so studies on flora of this periiod are of great significance. In recent years many palynological data of late Cretaceous and Paleocene have been recorded from different parts of China, especially the Southeastern China. An attempt is made here to allow deductions regarding the problem of existence of some palynological provinces during this period in China. Three provinces may be divided as follows. I. The wet subtropical and warm-temperate palynofioristical province of northeastern China. During late Cretaceous, this palynoflora was marked by occurrence of Aquilapollenites, Mancieorpus, Fibrapollis and Wodehouseia. Aquilapollenites amplus, A. crassus, A. megaprojeetus, A. asper, A. affenatus A. alatus, Mancieorpus andaensis, FiburapaUis mirifieus and Wodehouseia oeulata ...... are noted. Besides these eharacteriestic elements, there are many species of Proteaeiites and some species of Beaupreaidites, Loranthacites, Quereoidites, Salixipollenites, Gothanipollis, Plicapollis, Utmoideipites, Cranwellia, Alnipollenites and Trieolporopollenites. Gymnosperms pollen comprise Abietineaepollenites, Pinuspollenites, Cedripites, Taxodiaceaepollenites and Araueariacites. Sehizaeoisporites are very rich in species and numbers. Polypodiaceoisporites, Osmundacidites and Cyathidites are rarely Maud. Paleocene palynoflora is characterized by scantiness or absence of Aquilapollenites and Wodehouseia. Paraalnipollenites eonfusus, P. orthoeostatus, BetulaepoUenites pli eoides and some species of Myricipites, Comptonia and Momipites are predominant. These pollen may be related to Betulaceae, Juglandaceae and Myricaseae. Taxodiaceaepollenites, Cedripites and Podoearpidites are commen, It reflects that during late Cretaceous the flora was wet and subtropical, but in Paleocene, it turned to be wet and warm-temperate. According to the abundanee of Aquilapollenites and Wodehouseia, this palynoflora may belong to the Eastern AsianWestern North American Paly-nofioristical Province. II. Arid subtropical palynofioristieal province of South China. During late-Cretaceous this palynofiora comprises Morinopollenites Wang & Zhao (M. normalis, M. minor, M. polyprojeetus, M. rhombiformis) and Janhangpollis Wang & Zhao (J. radiatus, J. arciformis, J. sayaxngensis, J. ringes, J. mikros). Besides this, species of Proteacidites, Beaupreaidites, Myoporumpollenites, Crassimarginpollenites, Cranwellia, Magnolipollis, Rutaceoipollenites, Ilexpollenites, Symplocospollenites, Nyssapollenites, Palmaepollenites and Chenopodipollis were recorded. Classopollis, Exessipollenites and Rugubivesieulites were abundant in this assemblage. Aquilapollenites is rarely recorded, except along the coast region of eastern China. In paleocene some species of Nanlingpollis Sun & He, Pentapollenites jiangsiensis, Tricolporopollenites rombicus and Sapotaceoidaepollenitess trieoloporatus are recorded, but Morinopollenites and Janhanpollis were unknown. Ulmoideipites, Ulmipollenites, Ephedripites and some verrucate spores (Pterisispora) were very abundant. According to the feature of the pouch assemblages, the flora of South China during that time was of arid subtropical in nature. It seems to be nothing to do with other palynofloristical provinces in the world. III. Arid subtropical palynofloristical province of Northwestern China. Palynofiora of this period has been recorded from a few localities throughout this area. Normapolles group (Atlantopollis, Pseudoatlantopollis, Chaonopollenites, BasopoUis and ExtratriporopoUenites), Proteacigites microverrucatus, Eehitriporites magnus and Triatriapollenites echinatus were present. Besides that, Beaupreaidites, Rutaceoipollenites, Lonicerapollis and Engelhardtioipollenits were also occurred. In gymnosperms Ephedripites and some disaccate pollen were abundant. The percentage of Normapolles is increasing from east to west, while Proteaeidites is decreasing. In Paleocene Nudopollis and Trudopollis of Normapolles group were present, while Proteacidites 8issappeared. The palynoflora of this province was of an arid and subtropical in nature, which is somewhat in connection with the European-Eastern American Palynofloristical Province by the presence of Normapolles.  相似文献   

12.
Palynological assemblages are reported for the first time for the La Irene Formation, southwestern Santa Cruz Province, Argentina. This unit represents the sedimentation during a regressive period from transitional or delta-plain to fluvial environments. Palynological assemblages are scarce and moderately well preserved. They mainly consist of continental elements (wood remains, cuticles, spores and pollen grains) with scarse marine palynomorphs (dinoflagellate cysts). The spore-pollen assemblages are dominated by fern spores, followed by angiosperm and gymnosperm pollen grains. Bryophyte spores and fungal remains are also present. Among ferns, Cyatheaceae and spores of Laevigatosporites, of uncertain affinity, are dominant. Of the angiosperm pollen, those of Chloranthaceae (Clavatipollenites sp.) and Arecaceae (Arecipites spp., Longapertites sp., Spinizonocolpites hialinus Archangelsky and Zamaloa) are the most abundant. Pollen of Liliaceae (Liliacidites spp.), Proteaceae (Proteacidites sp., Peninsulapollis gillii (Cookson) Dettmann and Jarzen, Retidiporites camachoii Archangelsky) and Ericaceae (Ericipites scabratus Harris) are also present. Gymnosperm pollen is represented by Podocarpaceae (Podocarpidites spp.) and Ephedraceae (Equisetosporites sp.). These palynological suites would represent a fern-angiosperm dominated coastal vegetation, developed under warm and at least locally humid climatic conditions. La Irene Formation is considered Maastrichtian in age based on stratigraphic evidence, which is, in turn consistent with the ages suggested by the species ranges and the similarities observed with others previously described assemblages. This is the southernmost record of Spinizonocolpites, similar to the extant mangrove palm Nypa.  相似文献   

13.
Fossil pollen of Wodehouseia were first found by E. A. Stanley in 1961.There are several species of Wodehouseia found from the drill cores of the Lower member of Taizhou Formation in Rutung, North Jiangsu. It provides an evidence forjudging the Lower member of Taizhou Formation to be Maestrichtian age. In the assemblage of the Lower member of Taizhou Formation, there are not onlyAquiapollenites and Wodehouseia but also Morinoipollenites and Jianghanpollis. TheAquilapollenites and Wodehouseia are typical genera occurred in the humid, subtropicalclimatic phytogeoprovince in the “Aquilapolles District”, circumpacific and Siberiaduring Late Cretaceous age. The Morinoipollenites and Jianghanpollis are typical ge-nera occurred in the arid(or semiarid), subtropical climatic phytogeoprovince in widesouthern areas of our country at that time. This mixed assemblage provides a key tocompare the assemblage in wide southern areas of our country with those in other countries. The author discusses the geographical distributions and distributions of geologicalperiod of Wodehouseia in detail. The structure of Wodehouseia and the paleoecology of the parent plant of Wodehouseia pollen are explored. 7 species including 3 new spe-cies are described in this paper. The new species are Wodehouseia jiangsuensis sp. nov., W. circinata sp. nov., W. zoros sp. nov.  相似文献   

14.
甘肃平凉安国镇白垩系六盘山群的孢粉植物群   总被引:3,自引:0,他引:3  
对甘肃—宁夏交界处六盘山群一个露头剖面进行了孢粉分析,从和尚铺组、李洼峡组、马东山组和乃家河组中获得了孢粉化石。这些材料表明,六盘山群的孢粉植物群中白垩纪分子丰度高、分异度大,时代可能为晚Aptian—早、中Albian。孢粉反映当时的气候条件中性偏干,其中和尚铺组和乃家河组比李洼峡组和马东山组要更干一些。根据孢粉资料,六盘山群的和尚铺组至乃家河组的沉积可与盆地主体的志丹群的上部即泾川组对比,三桥组则可能相当于罗汉洞组。陕甘宁盆地西部边缘区缺少相当于志丹群宜君组至环河华池组的早白垩世早期的沉积。  相似文献   

15.
Pollen grains characteristic of the local pre-tricolpate, pre-Aptian phase of angiosperm evolution have been recovered from the upper part of the Six Hills Formation in the Dakhla Oasis area, Egypt. Highest abundance (up to 16.5 per cent) and diversity of angiosperm pollen is attained in samples from the Tineida 2 borehole, which also display a remarkable variety of different aperture types for a palynoflora of late Barremian age. Monosulcate, columellate tectates such as Retimonocolpites are most important, but a single trichotomosulcate grain as well as monoporate and inaperturate types that have not been reported from many coeval palynofloras, are also present. The following new taxa are described using same-grain SEM/LM techniques: Tucanopollis annulatus Schrank, sp. nov., Retimonocolpites pennyi Schrank and Mahmoud, sp. nov. and Retiacolpites columellatus Schrank, gen. et sp. nov. Phytogeographic links are closest with palynofloras previously described from the late Barremian of West Africa (Gabon, Congo), that is within the Northern Gondwana or Dicheiropollis etruscus/Afropollis Province.  相似文献   

16.
准噶尔盆地三工河组标准剖面孢粉植物群   总被引:1,自引:1,他引:0  
本文首次报道了准噶尔盆地三工河组标准剖面孢粉植物群:下部孢粉组合以裸子植物花粉在数量上居绝对优势,其中最为常见的有Abietineaepollenites,Aliporites,Cycadoites,Pinus-pollenites,Podocarpidites,Quadraedculina等分子;上部则表现为孢子在数量上占优势,其中Cyathidites和Deltoidospora的含量较下部明  相似文献   

17.
One hundred and thirteen species of spores and pollens belonging to 58 genera were found from 66 core samples taken from two boreholes of the Early and Middle Jurassic deposits in the Qiquanhu coal-field of the Turpan Basin, Xinjiang have been investigated in this paper. Two of the species are described as new. Three sporo-pollen zones from lower to upper are described as follows: Sporo-pollen zone Ⅰ (equivalent bed: Badaowan Formation) . The pteridophytic spores are slightly more abundant than the gymnospermous pollen in this assemblage. The most abundant spores are Cyathidites minor, C. australis and Undulatisporites pflugii, U. taenus and so on. The second important fern spores are Osmundacidites, Lycopodiumsporites, Apiculatisporis and Duplexisporites. The most important gymnospermous genus is Cycadopites which ranks highest in the assemblage and includes C. nitidus and C. typicus.The other gymnospermous pollen include Classopollis, Pinuspollenites, Protoconiferus Piceites. Besides, there are a few pollen grains of Taeniaesporites and Chordasporites surviving from the Late Triassic in this assemblage. The present assemblage may be compared with the Early Jurassic sporopollen assemblage from the Daling Formation of the North-East Guangxi. Therefore, the Badaowan Formtion may be referred to Early Jurassic in age, probably Early Lias. Sporo-pollen zone Ⅱ (equivalent bed: Sangonghe Formation) In this assemblage the gymnosperms are predominant.Of them, Podocarpidites and Pinuspollenites increase obviously, and Quadraeculina and Protoconiferus are common. Few surviving elements are observed. The most abundant spores are those of Cyathidites, and the particularly abundant pollens are those of Cycadopites, This assemblage may be compared with the Late Lias sporo-pollen assemblage from the Fuxian Formation of the Northern Shangganning Basin. Therefore, the Sangonghe Formation should belong to Early Jurassic, probably Late Lias in age. Sporo-pollen zone Ⅲ (equivalent bed: Xishanyao Formation). The contents of the spores and pollens are almost equal in this assemblage. Cyathidites and Cycadopites are the most important spores and pollen. Osmundacidites and Quadraeculina are common. Neoraistrickia, Lycopodiumsporites and Eucommiidites troedssonii are present. Ancient striate bisaccate pollen disappears. The characteristics of this assemblage show some resemblances to those of the Middle Jurassic Yanan Formation in Chongxin county of Gansu province. So the Xishanyao Formation should belong to Middle Jurassic.  相似文献   

18.
江苏宜兴龙池山现代植被表土孢粉的初步研究   总被引:2,自引:0,他引:2  
江苏宜兴龙池山森林自然保护区表土花粉分析结果表明,表土孢粉植物群主要以栎属(Quercus)、松属(Pinus)、青冈属(Cyclobalanopsis)、栲属(Castanopsis)/柯属(Lithocarpus)、栗属(Castanea)占优势的木本植物组成,混生有枫香属(Liquidambar)、杨梅属(Myrica)、冬青属(Ilex)、女贞属(Ligustrum)、紫树属(Nyssa)、盐肤木属(Rhus)、黄连木属(Pistacia)等亚热带常见植物类型。研究区不同海拔高度的表土孢粉组合特征基本反映了当地现今的植物构成、植被面貌及其垂直分布规律。结合长江三角洲及其周边地区其他代表性表土花粉资料,首次提出以常绿阔叶木本植物与落叶阔叶木本植物含量之比(E/D),并结合重要优势、标志木本植物科属,初步识别和确立各地带性森林植被的表土花粉指标,为这一地区开展第四纪古植被和古气候等孢粉研究提供参考性依据。  相似文献   

19.
One hundred and eight species of fossil spores and pollen referred to 55 genera found from the Lower Cretaceous Kapushaliang (Kizilsu) Group in the Tarim Basin of Xinjiang have been studied in this paper. The Kapushaliang Group may be divided into the Yageliemu Formation, the Shushanhe Formation and Baxigai Formation in ascending order. The Yageliemu palynoflora is characterized by the predominance of gymnospermous pollen, the relative abundance of pteridophytic spores and the absence of angiospermous pollen. Coniferae is dominant, while Lygodiaceae and Schizaeaceae are important in the flora. The most common species of palynomorphs are Todisporites minor, Cicatricosisporites dorogensis, C. australiensis, Lygodiumsporites subsimplex, Schizaeoisporites cretacius, S. zizyphinus, S. certus. Cibotiumspora paradoxa, Cyathidites australis, C. minor, Biretisporites potoniael, Cycadopites minimus, Pseudowalchia hiangulina, Parvisaccites radiatus, Podocarpidites multesimus, P. canadensis, Alisporites bilateralis, Cedripites cretaceus, C. canadenris, Abietineaepollenites microalatus, Clarsopollis classoides, C annulatus, C. xinjiangensis (sp. nov.), Ephedripites multicostatus, E. tarimensis (sp. nov.), etc . The palynoflora is comparable with those of the lower part of the Lower Xinminbu Formation in northwestern China and the lower part of the Lower Mannville Formation in western Canada, which is considered corresponding from Berriasian to Valanginian in age. The Shushanhe palynoflora is also characterized by dominance of gymnosperms and subdominance of pteridophyta. Some primitive angiospermons pollen grains are found in the upper part of the formation. In addition to the most common species of the above mentioned palynoflora, the important species in the present palynoflora comprise Cicatricosisporites potomacensis, C. orbiculatus, C. subrotundus, Concavissimisporites punctatus, C. verrucosus, C. globosus, lmpardecispora apiverrucata, Trilobosporites crassus, T. trioreticulosus, Pilosisporites verus, P. trichopapillosus, Klukisporites pseudoreticulatus, Verrucosisporites obscurilaesuratur, Converrucosisporites saskatchewanensis, Foraminisporis wonthaggiensis, Cingulatisporites valdensis, C. ruginosus, Jiaohepollis verus, Pityosporites constrictus, etc. More than 40 in dicative species of Early Cretaceous occur in the assemblage. The palynoflora compares clcsely with those of the middle part of the Lower Xinminbu Formation and the Quartz Sand Member of the Lower Mannville Formatton. It is suggested that the Shushanhe Formation should belong to Hauterivian of Barremian in age. The Baxigai palynoflora is basically similar to the Shushanhe palynoflora. But the palynoflora shows an obvious increase in abundance of lygodiaceous spores and angiospermous pollen accompanied by a great reduction of Classopollis and Ephedripltes. Most of the Early Cretaceous species occurring in the above mentioned palynofloras are present. In addition, some Cretaceous species recorded from Aptian and Albian Stages in Europe, North America and Australia, such as Trilobosporites tribotrys, T. trioreticulosus, Coptospora paradoxa, Camarozonosporites insignis, Crybelosporites punctatus, etc., appear in the assemblage. In comparison with the microfloras of the upper part of the Lower Xinminbu Formation, the Upper Mannville Formation and the lower part of the Lower Colorado Group, the Baxigai Forma- tion should be referred to Aptian to Albian in age. Judging from the palynofloras, the early Cretaceous palaeoclimate in the basin should belong to the arid or semi-arid type of the subtropic zone. However, from Barremtan through Albian the climatic conditions might appear relatively wet.  相似文献   

20.
天津张贵庄晚二叠世孢粉植物群   总被引:4,自引:1,他引:3  
天津张贵庄SR13号钻孔原归为石盒子组的地层近顶部发现了丰富的孢粉化石,这一组合兼具上石盒子组和孙家沟组孢粉组合的特征。一方面,它与上石盒子组(特别是其上部)组合有不少共同分子,在蕨类孢子和裸子植物花粉(包括具肋花粉)的含量比例上也可以与之对比,但缺乏一些标志分子。另一方面,在属种组成上,当前组合与已知的孙家沟组合也颇可比较,而且出现了一些中生代色彩的分子。这一组合的揭示与研究有助于提高人们对华北晚二叠世晚期孢粉植物群特征的认识。依据当前组合与已知相关孢粉组合的对比讨论,将其时代定为晚二叠世,并倾向于晚二叠世晚期(对应于孙家沟组)。  相似文献   

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