首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到19条相似文献,搜索用时 269 毫秒
1.
粤北塘村盆地文明司组的介形类化石计有8属20种,本文描述其中5属13种,称Cypridea epimeco-Mon-golocypris subin fidelis组合,它以早白垩世极度繁盛的Cypridea占绝对优势及全为小个体的Mongolocypris为代表,这个介形类组合可与湖南汝城文明司组的介形类进行对比,时代属早白垩世晚期Aptian期。  相似文献   

2.
松辽盆地南部沙河子组和泉头组介形类   总被引:4,自引:1,他引:3  
本文首次报道松辽盆地南部内蒙古科尔沁左翼后旗金宝屯地区沙河子组和泉头组下部非海相介形类11属26种,其中沙河子组6属10种,泉头组下部8属18种(包括6新种和1新亚种)。沙河子组以Cypridea(Cypridea) unicostata-C.(Yumenia) casta-Limnocypridea abscondida为代表的介形类化石组合,时代属早白垩世早中期;泉头组下部以Cypridea(Pseudocypridina),limpida C.(Cypridea) albidula seclucarinalis-Paracandona planiuscula为代表的组合,时代为早白垩世晚期。  相似文献   

3.
河南周口盆地早白垩世商水组介形类   总被引:1,自引:0,他引:1  
本文首次报道了河南周口盆地商水组以Cypridea-Candona-Darwinula为代表的介形类化石组合。它由7属19种(包括5新种和1未定种)组成,其组合特征与国内外广泛分布的早白垩世非海相介形类化石组合特征相同。根据这一介形类化石组合中Cypridea(Pseudocypridina)占优势且出现较多的Candona,Candoniella属的分子,其时代应为早白垩世阿普第—阿尔必期。商水组的层位与河北南部丘城组和松辽盆地姚家组大体相当。  相似文献   

4.
描述的介形类化石标本采集于新疆塔里木盆地库车和喀什两地区,其中,齐古组产Darwinula-Timiriasevia组合,恰克马克组产Darwinula-Bisulcocypris为代表的介形类化石组合,其时代前者为晚侏罗世,后者为中侏罗世;俄霍布拉克组和克拉玛依组产以Bisulcompris-TungchuaniaDarwinula为代表的组合,其时代为早-中三叠世。  相似文献   

5.
本文描述和图解介形类化石10属、4亚属和14种,包括1新属(Paraulrichia)和6新种。其中古足目类8属、3亚属和12种;豆石目类1属、1亚属和1种;显壳亚目类1属和1种。这些介形类化石分别采自云南宁蒗大槽子泥盆系剖面大槽子组和碳山坪组。根据介形类组合特征,大槽子组的地质时代为晚埃姆斯期,碳山坪组下、中部的地质时代可能属晚埃姆斯期。介形类生态组合属古足目-平足目集群,代表局限的碳酸盐台地环境。在生物地理上,与泥盆纪华南介形类动物地理区系一致。  相似文献   

6.
该文首次报道了江汉盆地可能属于古新世的非海相地层及其中的介形类化石,计有17属30种(其中新种3个),隶属于3个超科。该介形类动物群自下而上可分为:1.Porpocypris(?)-Paraily-ocypris-Cypridea组合;2.Sinocypris-Eucypris-Limnocythere组合。第2组合完全可与广东南雄盆地罗佛寨组的介形类化石群对比,时代可能为古新世晚期;第1组合的介形类是否可与广东南雄盆地上湖组的化石对比的问题,还有待今后发现更为可靠的Porpocypris属的代表分子来解决,这里暂置于古新世早、中期。  相似文献   

7.
郑淑英 《古生物学报》1995,34(6):722-730
描述的介形类化石标本采集于新疆塔里木盆地库车和喀什两地区,其中,齐古组产Darwinula-Timiriasevia组合,恰克马克组产Darwinula-Bisulcocypris为代表的介形类化石组合,其时代前者为晚侏罗世,后者为中侏罗世;俄霍布拉克组和克拉玛依组产以Bisulcompris-TungchuaniaDarwinula为代表的组合,其时代为早-中三叠世。  相似文献   

8.
内蒙古海拉尔盆地南部地区晚白垩世青元岗组介形类   总被引:1,自引:0,他引:1  
内蒙古海拉尔盆地南部探井青元岗组红色碎屑岩中发现较丰富的介形类化石,即下段的Ahanicypris obesa-Talicypridea triangulata组合和上段的Chinocypridea augusta-Talicypridea qingyuangangensis组合,这些介形类化石地方性色彩强烈,表现为以具冠状壳喙类型的Ahanicypris,Talicypridea,Chinocypridea和网纹发育的Harbinia等属繁盛为特征,反映了中国东北地区晚白垩世晚期介形类动物群面貌。根据介形类化石组合特征及其分布规律,可以与松辽盆地晚白垩世四方台组的介形类动物群对比,时代为晚白垩世Maastrichtian期。  相似文献   

9.
甘肃玉门下沟地区早白垩世下沟组介形类   总被引:3,自引:1,他引:2  
甘肃玉门下沟地区下沟组介形类化石十分丰富,该地区下沟组介形类化石共计9属4亚属,21种,本文描述了其中4新种,即Cypridea(Cyamocypris)xiagouensissp.nov.,Cypridea(Cypridea)subunicostatasp.nov.,Stenestroemiasubpeculiarissp.nov.和Stenestroemiaxiagouensissp.nov.。该介形类化石组合尤以Cypridea最为繁盛,通过分析介形类属种的形态特征和化石组合特征并结合岩性特征,推断下沟组的地质时代为早白垩世巴列姆期;并认为下沟组为水动力较弱的淡水-微咸水河湖相沉积。  相似文献   

10.
通过对青海省循化县积石镇羊圈贡拜村-西沟中新统-上新统实测剖面中介形类动物群的研究,在其中的35个层位样品中发现含介形类化石7属32种,并建立了两个组合:(1)Candona-Candoniella组合;(2)Ilyocypris-Candoniella-Candona组合。依据介形类组合带,将咸水河组上部时代厘定为中新世中期,而临夏组时代厘定为中新世晚期-上新世早期。根据介形类动物群在剖面上的分布规律,自下而上建立5个生态组合:(1)Candona-Can-doniella生态组合;(2)Ilyocypris errabundis-Ilyocypris dunschanensis生态组合;(3)Candona-Candoniella生态组合;(4)Ilyocypris biplicata-Candoniella生态组合;(5)Candonaoppressa-Candona exti ma生态组合。通过对介形类生态组合进行详细的生态特征分析,结合磁性年代学数据,将循化盆地14.6-5Ma的古气候划分为5个阶段:(1)14.6-9.5Ma为凉干期;(2)9.5-9.38Ma为热干期;(3)9.38-6.88Ma为冷干期;(4)6.88-6.83Ma为温干期;(5)6.83-5Ma为凉干期。  相似文献   

11.
张雄华 《古生物学报》2002,41(2):283-294
通过对黔南地区晚石炭世及早二叠世早期四射珊瑚的研究,建立4个四射珊瑚组合,自下而上:1)Antheria-Pseudotimania组合;2)Nephelophyllum-Eokepingophyllum组合;3)Parawentzellophyllum-Kepingophyllum组合;4)Anfractophyllum组合。组合1、2以Cyathopsidae科分子和Kepingophyllidae科的原始分子为主;组合3以Kepingophyllidae科的典型分子为代表;组合4以Kepingophyllidae的进化型分子为特征。文中描述四射珊瑚9新种及1未定种。  相似文献   

12.
《Marine Micropaleontology》1999,37(2):131-147
Cainozoic deep-sea ostracod assemblages from the summits of Mid-Pacific guyots point to high levels of endemism possibly as a result of their bathymetric separation from the surrounding sea floor. However, the interpretation of these fossil assemblages is hampered by the paucity of comparative material from surrounding non-guyot sites. Fifteen ostracod assemblages from DSDP Site 463 (Late Cretaceous-Pleistocene) were studied to compare with those from nearby guyots. Three distinct faunal assemblages are recognised at Site 463: Assemblage A (Maastrichtian-Eocene), Assemblage B (Oligocene-Upper Miocene) and Assemblage C (Upper Miocene-Pleistocene) although the palaeoenvironmental significance of these units is unclear. Sixty-two ostracod species are identified, the thirteen most abundant are discussed in the taxonomic section, five of which are described as new. Between 30 and 100% of the species encountered in each sample are considered as endemic to Site 463, while some of the remaining species were previously thought to be endemic to individual guyots. Similarly high levels of endemism on nearby guyots probably reflect an incomplete knowledge of deep-sea ostracod faunas rather than the establishment of geographically or bathymetrically restricted populations. The presence of globally pandemic and geographically widespread taxa on sites such as the Mid-Pacific Mountains, surrounded by abyssal depths which lie below the CCD, indicates that some faunal exchange or migration of ostracods does take place. This must be achieved within the intermediate waters and probably occurs passively.  相似文献   

13.
青海省南部治多-杂多一带早石炭世有孔虫动物群   总被引:2,自引:0,他引:2  
在青海省南部的治多—杂多一带1/25万地质填图中,于杂多群中首次发现非筵有孔虫,建立2个组合,即Endothyra-Mediocris—Archaediscus组合和Bradyina-Endothyranopsis组合,地质时代为早石炭世大塘期德坞期,与华南、塔里木盆地、西秦岭、前苏联等地同期生物群可很好地对比,同时结合大冢相似系数的计算表明,青海南部地区在早石炭世属于特提斯大区华夏生物区华南省。  相似文献   

14.
Animal assemblages fulfill a critical set of ecological functions for ecosystems that may be altered substantially as climate change‐induced distribution changes lead to community disaggregation and reassembly. We combine species and community perspectives to assess the consequences of projected geographic range changes for the diverse functional attributes of avian assemblages worldwide. Assemblage functional structure is projected to change highly unevenly across space. These differences arise from both changes in the number of species and changes in species’ relative local functional redundancy or distinctness. They sometimes result in substantial losses of functional diversity that could have severe consequences for ecosystem health. Range expansions may counter functional losses in high‐latitude regions, but offer little compensation in many tropical and subtropical biomes. Future management of local community function and ecosystem services thus relies on understanding the global dynamics of species distributions and multiscale approaches that include the biogeographic context of species traits.  相似文献   

15.
Benthic foraminiferal composition assemblages and their temporal changes, ecological indices and foraminiferal densities are used to compare three coastal environments with different physicogeographical features in the Aegean Sea (coastal environment of Avdira–Vistonikos Gulf and Kitros–Thermaikos Gulf and open lagoonal environment of Vravron–South Evoikos Gulf). Three main foraminiferal assemblages have been recognized: a) “Assemblage A”; high degree of similarity between living and dead foraminiferal species, dominated by Ammonia beccarii, Elphidium spp. and relatively abundant and diverse miliolids, b) “Assemblage B1”; intermediate degree of similarity between live and dead assemblages, characterized by highly-abundant and well-diversified foraminiferal assemblages including the algal symbiont bearing Peneroplis pertusus together with Ammonia tepida and several small epiphytic rotaliids and miliolids, and c) “Assemblage B2”; absence of living individuals, strongly dominated by the opportunistic species A. tepida. Our results suggest a good comparison between living and dead assemblages from different coastal environments in the Aegean Sea, however the prevailing environmental conditions (vegetation cover, hydrodynamics, fresh water influx) have a strong impact on the taphonomic processes.  相似文献   

16.
广西合浦盆地上洋组在亚1井中有很好的揭示,明显表现为三分特征。作者通过对该井上洋组微体植物化石的研究,建立了三个孢粉、藻类组合,由下而上分别为:Boehlensipollis-Tricolporo-pollenites-Tricolpites-Ulmoideipites组合;Boehlensipollis qingjiangensis-Ulmoideipites-Nuxpollen-ites-Pentapollenites组合和Pinaceae-Ulmaceae-Liqudambarpollenites-Conicoidium组合。前两个组合可与北部湾长流组及广东南雄盆地上湖组等地古新世孢粉组合进行对比。第三个组合以松科花粉含量突然增加为特征,在我国许多地区晚古新世孢粉组合中都有反映。 上洋组植被在古新世早、中期以阔叶植物为特征,指示一种热带—亚热带型气候,早期干旱,中期略有缓和,晚期植被以针叶阔叶混交林为特征,表明气候变温凉。  相似文献   

17.
通过对山东新汶煤田太原组小有孔虫动物群的系统研究,共鉴定出小有孔虫化石24属66种,根据小有孔虫在太原组中的垂向分布和含量的变化,自下而上分为3个小有孔虫组合:1.Brad yina samarica- Palaeotextularia angusta elongata组合,2.Nodosaria sinensis- Tetrataxis组合,3.Geinitzina postacarbonica组合。通过与邻区及华北部分地区的对比,本区太原组小有孔虫动物群的地质时代应归属于早二叠世,其层位大致相当于华北各地太原组(ting)类的Pseudoschwagerina带。  相似文献   

18.
Giardia duodenalis a species complex of gastrointestinal protists, with assemblages A and B infective to humans. To date, post-genomic proteomics are largely derived from Assemblage A, biasing understanding of parasite biology. To address this gap, we quantitatively analysed the proteomes of trophozoites from the genome reference and two clinical Assemblage B isolates, revealing lower spectrum-to-peptide matches in non-reference isolates, resulting in significant losses in peptide and protein identifications, and indicating significant intra-assemblage variation. We also explored differential protein expression between in vitro cultured subpopulations putatively enriched for dividing and feeding cells, respectively. This data is an important proteomic baseline for Assemblage B, highlighting proteomic differences between physiological states, and unique differences relative to Assemblage A.  相似文献   

19.
We compared the assemblages of phyllostomid bats in three Neotropical rainforests with respect to species richness and assemblage structure and suggested a method to validate estimates of species richness for Neotropical bat assemblages based on mist-netting data. The fully inventoried bat assemblage at La Selva Biological Station (LS, 100 m elevation) in Costa Rica was used as a reference site to evaluate seven estimators of species richness. The Jackknife 2 method agreed best with the known bat species richness and thus was used to extrapolate species richness for an Amazonian bat assemblage (Tiputini Biodiversity Station; TBS, 200 m elevation) and an Andean premontane bat assemblage (Podocarpus National Park; BOM, 1000 m elevation) in Ecuador. Our results suggest that more than 100 bat species occur sympatrically at TBS and about 50 bat species coexist at BOM. TBS harbours one of the most species-rich bat assemblages known, including a highly diverse phyllostomid assemblage. Furthermore, we related assemblage structure to large-scale geographical patterns in floral diversity obtained from botanical literature. Assemblage structure of these three phyllostomid assemblages was influenced by differences in floral diversity at the three sites. At the Andean site, where understorey shrubs and epiphytes exhibit the highest diversity, the phyllostomid assemblage is mainly composed of understorey frugivores and nectarivorous species. By contrast, canopy frugivores are most abundant at the Amazonian site, coinciding with the high abundance of canopy fruiting trees. Assemblage patterns of other taxonomic groups also may reflect the geographical distribution patterns of floral elements in the Andean and Amazonian regions.  © 2008 The Linnean Society of London, Biological Journal of the Linnean Society , 2008, 94 , 617–629.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号