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11.
本文简要叙述了松辽盆地泉头组三、四段的沉积特征,详细讨论了泉头组三、四段及其所属扶余、杨大城子油层介形类化石的分布,总结出划分油层和油层组的介形类标志化石。利用这些介形类标志化石可进一步将扶余油层细分为三个油层组,杨大城子油层细分为五个油层组,为油层细分层对比提供了古生物依据。  相似文献   
12.
山东莱阳盆地早白垩世莱阳群的遗迹化石   总被引:9,自引:1,他引:9  
山东莱阳早白垩阳群自下而上分为瓦屋夼组,林寺山组,止风庄组,水南组,龙旺庄组和曲格庄组。为一套河湖相沉积,产有较丰富,分异度较高的非海相遗迹化石和兽脚类恐龙足迹化石,共鉴定出遗迹属11个,未定属1个,其中遗迹种9个,未定种2个,遗迹化石是:Cochlichnus anguines,Diplocraterion parallelun,Helminthoidichnites tenuis,Palaeophycus tubularis,Planolites montanus ,Scolica sp.,Scoyenia gracilis,Skolithos linearis,Taenidium cameromensis,Thalassinoides sp.,恐龙足迹化石是:Paragrallator yangi,这些化石按习性可分为4类,即:居住构造, 爬行迹,觅食[迹和牧食迹,其中又以前3种为主,遗迹化石在剖面上的分布不均匀,以上部的水南组,龙旺庄,曲格庄3个组最丰富。  相似文献   
13.
Abstract:  In Ordovician ostracodes (genus Incisua ) a new kind of sexual dimorphism is described, which is the first example among this group with males being the heteromorphs. The valves of males are larger and less frequent than the females, and are characterized by having a furrow in the ventral part. The furrow may have functioned as a device to enable the two sexes to cling together during mating.  相似文献   
14.
湖南湘乡上泥盆统佘田桥组介形类   总被引:1,自引:1,他引:1  
本文首次报道了湖南湘乡上泥盆统佘田桥组介形类化石,共有18属35种及未定种,其中包括11新种。通过与国内外泥盆纪和早石炭世介形类进行比较表明,它们与下伏的中泥盆统棋梓桥组介形类组合和上覆的上泥盆统锡矿山组介形类组合均有明显的差别,该介形类动物群的发现,为佘田桥组的地质时代的确定及地层的划分对比提供了新的古生物依据,并对研究介形类动物群的演化增加了新的资料。  相似文献   
15.
本文记述的介形类化石采自塔里木盆地北部柯坪地区大湾沟剖面坎岭组,共计8属14种。其中包括2新种和3未定种。Thrallella.Octonaria,Predarwinula三属为本介形类组合最为重要且最具特色的分子。据此推测,坎岭组时代为晚奥陶世中期(Caradocian)。  相似文献   
16.
由于志留泥盆纪之间没有发生明显的生物更替现象,所以泥盆纪最早期(Lochkovian)的珊瑚仍保留着浓厚的志留纪珊瑚的色彩。真正的泥盆纪类型的珊瑚是从早泥盆世中期(Pragian)才开始兴起的,至晚泥盆世早期(Frasnian)末惨遭绝灭。晚泥盆世晚期(Famennian)的珊瑚却与石炭纪珊瑚有着较为密切的关系。晚泥盆世的珊瑚经历了绝灭残存复苏3个发展阶段。泥盆石炭纪之交,泥盆纪最晚期(Strunian)的珊瑚再遭绝灭,至石炭纪初代之于Tournaisian型的珊瑚。正当华南锡矿山(相当于Famennian早期)的珊瑚群罹难的时刻,新疆北部洪古勒楞(亦相当于Famennian早期)却形成了F/F大绝灭后生物理想的避难所。  相似文献   
17.
桑干河流域晚更新世介形类   总被引:1,自引:0,他引:1  
本文研究了河北涿鹿县桑干河南岸二级阶地上更新统吉家营组的介形类化石,描述5科9属12种,其中1新种、1未定种。本文对介形类的生态环境也作了初步探讨,认为晚更新世此区属淡水、浅水环境,气候偏冷。  相似文献   
18.
作者在《中国灵芝科志》的编写过程中,从中国科学院微生物研究所真菌标本室(HMAS)中发现我国尚未报道过的灵芝科4个新记录种,它们是:唐氏灵芝GanodermadonkiiSteyert、亮黑灵芝G.nigrolucidum(Loyd)Reid、壳状灵芝G.ostracodesPat.和具柄灵芝G.stipitatusMurr。以上所有研究标本均保藏在HMAS。  相似文献   
19.
云南鹤庆晚第四纪介形类生态特征初探   总被引:5,自引:1,他引:5  
云南鹤庆盆地晚第四纪钻孔剖面分析出介形类13属,32种,多为地方性属种,根据介形类丰度,分异度,百分含量及组合分子在剖面中的分布情况,结合剖面同步分析的总有机碳含量(TOC),碳-氮比(C/N),碳酸盐含量,孢粉等数据,并利用已有相关的介形类生态资料,对介形类生态特征进行初步探讨。研究结果表明:温度,矿化度,水流动态,水循环状况,pH值,深度,湖泊流域生产力等环境因素对介形类组合面貌,定量数据,壳饰等特征均有一定影响,其中,介形类丰度,分异度与温度,矿化度关系最为密切。  相似文献   
20.
Aim This paper aims to examine the relationship between versatility as measured by geographic range, bathymetric range and morphological variability (species and subspecies richness and the occurrence of morphologically highly variable populations), and the geologic longevities of trachyleberidid ostracode species and genera, while accounting for sampling biases and other confounding factors. Location Global. Methods A large database of occurrence records of species of the family Trachyleberididae s.l. was analysed. The relationships between genus and species longevity and the above mentioned variables were examined singly and in concert. Re‐analyses of subsets of data and rarefaction techniques were employed to account for sampling biases, while randomization was used to account for autocorrelation of variables. Results The mean number of occurrence records, and latitudinal and longitudinal ranges, were strongly and positively correlated with genus and species longevities. The number of bathymetric zones occupied by genera had no consistent bearing on their longevities, but species data subsets tended to indicate significant positive relationships between bathymetric range and longevities. Species richness was significantly and positively correlated with genus longevities. Species and genera with subspecies and species with high morphological variability all had significantly greater longevities. Genus‐level characteristics can be explained largely by species‐level characteristics, including longevity, latitudinal ranges and bathymetric ranges to a lesser degree. However, genus longevity was best explained by species richness and genus age, even for extinct genera, while species longevity was best explained by species latitudinal range. Main conclusions In spite of the incompleteness of the fossil record, we can control for biasing factors and still confidently draw the conclusion that both ecological and evolutionary versatility contribute to lineage longevity, beyond the shorter temporal observation windows available to most ecological studies.  相似文献   
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