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 125 毫秒
1.
中国新疆塔里木盆地上奥陶统良里塔格组的钙藻化石   总被引:1,自引:0,他引:1  
钙藻是可以发生生物钙化作用形成钙质"骨骼"的分属多个门类的藻类的俗称。钙藻最早出现于寒武纪,奥陶纪发生第一次辐射演化。本文系统讨论了绿藻门绒枝藻目(Dasycladales)、羽藻目钙扇藻科(Udoteaceae)的科和属级分类标准和红藻门珊瑚藻科、管孔藻科(Solenoporaceae)属级分类标准及其中各属分类中存在的问题。塔里木盆地晚奥陶世在塔中—巴楚台地和塔北台地发育了一套礁滩相良里塔格组碳酸盐岩,其中含有丰富的钙藻化石。本文系统描述了来自塔里木盆地塔中、巴楚、塔北地区取心井上奥陶统良里塔格组岩层中的钙藻化石11个属15个种。包括绿藻门绒枝藻目西莱特藻科(Seletonellaceae)的Dasyporella,Kazakhstanelia,Vermiporella,Aphroporella,Arthroporella,绿藻门的羽藻目Bryopsidales(siphonales)的钙扇藻科的Dimor phosiphon,Palaeo porella,红藻门珊瑚藻目(Corallinales)的管孔藻科的Solenopora,Parachaetetes及Corallinales incertus familiae的Petro-phyton,以及分类位置不明的Monili porella。其中绒枝藻Ajakmalajsoria被视作Kazakhstanelia的同义名。  相似文献   

2.
河北张家口下花园青白口系下马岭组"红藻石"的发现   总被引:6,自引:1,他引:5  
红藻石由红藻形成。绝大部分红藻石与珊瑚藻有关。珊瑚藻形成的红藻石发育于中新生代,早古生代有管孔藻形成的红藻石。本文记录了发现于下花园地区的新元古代青白口系下马岭组四段的红藻石。这类红藻石的中心部分被沥青充填。通过薄片观察发现沥青饼的周围硅化部分存在两类红藻四分孢子囊:一类四分孢子囊包埋于球状构造内,另一类四分孢子囊包埋于叶片状构造内。  相似文献   

3.
串珠藻目植物的系统发育-基于rbcL序列的证据   总被引:4,自引:0,他引:4  
世界范围内报道的全部串珠藻目种类均生活于淡水中,而在淡水红藻中,70%约有130种属于串珠藻目。研究以目前获取的来自世界各大洲串珠藻目植物43种的rbcL基因序列,结合其形态和生物地理特征,构建了该目的系统发育关系,以期探讨整个串珠藻目植物的系统发育关系及发生途径,进而为研究该目以至淡水红藻的起源提供基本资料。运用PAUP*4.0b10和MrBayes 3.0b4等软件对43种串珠藻目植物的叶绿体DNA rbcL基因序列进行系统发育分析,探讨了其主要分类群的系统演化关系。用最大简约法、邻接法和贝叶斯分析方法构建的系统树基本一致,结果显示:(1)基于分子数据分析结果显示,红索藻目植物均独立于串珠藻目植物,构成一个单独的分支,支持红索藻目的建立。(2)鱼子菜科属于串珠藻目植物中较为进化的类群。(3)串珠藻属扭曲组与杂生组的差异度较小,结合其形态特点,倾向于将杂生组并入扭曲组。(4)串珠藻科属于串珠藻目中最大的科,包括较多的种类,其系统关系也较为复杂。因此,串珠藻科系统发育关系的明确有待于进一步结合更多的分子数据和形态学特征加以分析研究。    相似文献   

4.
植物分类学在化石珊瑚藻(珊瑚藻目,红藻门)中的应用   总被引:5,自引:0,他引:5  
最近有人认为将化石藻类的分类归入现生藻类分类单元有利于珊瑚藻作为古环境的标志,便于理解该类群的演化。然而,这样分类可能很难,因为并不是所有现生藻类分类特征都能在化石种中保存下来。Sporolithacea科的钙化部分(独立或者聚集的孢子囊群)的出现,可以把它们与这个类群的另一个现生科Corallinaceae区别开,这个科在生殖窠中产生孢子囊。节片的有无,丝间细胞的联系类型,生殖窠中孢子囊释放的数目都是用来划分Coral1inaceae科的亚科的标准,在化石样品中也可以用合适的条件进行观察。在大多数情况下,对现生珊瑚藻类属的划分特征可以在化石藻类中鉴别出来,但在几种现生珊瑚藻没有钙化的生殖结构或发育特征。因此,它们生殖结构无法与相应的化石藻类进行对比,也不能进行化石藻类的分类。近年来的趋势认为生殖结构和发育特征是对现生珊瑚藻进行分类的优先鉴定标准,然而,某些特征的稳定性在属的划分上仍然存在争论。在许多情况下,现生藻类的分类标准特征都不能在化石中保存,对古生物化石的分类标准的最佳选择是在化石藻类中选择辅助的,并且可以识别的其它鉴定特征,或者应用非正式的比现生藻类代表定义更宽的属名。  相似文献   

5.
本文对中国南海西沙群岛琛科2井中新世以来的珊瑚藻组成进行了初步研究,共识别出3科4亚科11属,包括石叶藻亚科石叶藻属(Lithophyllum)和蟹手藻属(Amphiroa);宽珊藻亚科似绵藻属(Spongites)、新角石藻属(Neogoniolithon)和石孔藻属(Lithoporella);珊瑚藻亚科让氏藻属(Jania)和珊瑚藻属(Corallina),无节珊瑚藻亚科中叶藻属(Mesophyllum)、奇石藻属(Aethesolithon)和石枝藻属(Lithothamnion);孢石藻亚科孢石藻属(Sporolithon)。并得出以下认识:(1)珊瑚藻类群,指示浅水环境;无节珊瑚藻类群,指示深水环境;宽珊藻类群,指示最浅水环境;石叶藻类群,指示浅水环境。(2)琛科2井自下而上分为7个组合:让氏藻属-珊瑚藻属-石孔藻属组合;奇石藻属组合;中叶藻属-石枝藻属组合;似绵藻属组合;石枝藻属组合;中叶藻属-石叶藻属组合;石孔藻属-石叶藻属组合。(3)878.21 m的珊瑚礁碳酸盐岩心,以309.00-312.00 m为界,分为两个大沉积旋回。第一个沉积旋回珊瑚藻组合经历了具关节的珊瑚藻属-让氏藻属-石孔藻属组合,奇石藻属组合,石枝藻属-中叶藻属组合,似绵藻属组合的变化,反映了水体由浅加深,到最后又变浅的过程;第二个沉积旋回珊瑚藻组合出现了似绵藻藻属组合,石枝藻组合,中叶藻属-石叶藻属-石孔藻属组合,石叶藻属组合的变化,反映了水体由浅加深再变浅的珊瑚藻组合的相应变化。  相似文献   

6.
本研究采用贝叶斯法(Bayesian-inference,BI)、最大似然法(Maximum-likelihood,ML)和最大简约法(Maximumparsimony,MP),基于18SrDNA序列对介形纲4目12超科间以及其它相关泛甲壳动物(Pancrusacea)间的系统分类关系进行了分析,其目的是探讨单独的核基因18SrDNA序列研究介形纲各阶元分类时的稳定性,及分析介形纲两大主要类群内的系统分类关系。结果发现,应用单独的核基因18SrDNA序列对介形类进行研究时,所获的三种系统树的拓扑结构在介形纲的目、亚目和超科阶元均表现稳定,表明单独的核基因18SrDNA序列在该3个阶元的分类研究中可发挥重要作用。基于此,进一步对介形类内两主要类群的系统分类研究,结果支持Martin和Davis(2001)对介形纲中壮肢亚纲(又称丽足亚纲,Myodocopa)在目、亚目和超科阶元上的分类;但尾肢亚纲(又称速足亚纲,Podocopa)中各主要类群间的系统发育关系却与Martin和Davis(2001)的分类略有不同,其中Punciidae游离于尾肢亚纲主要类群尾肢目(又称速足目,Podocopida)之外,而该结果却与Liebau(2005)对Punciidae归类一致;此外尾肢目中5个主要类群的分类关系呈现[浪花介亚目Cytherocopina+[金星介亚目Cypridocopina+简肢亚目Platycopina(小花介科Cytherellidae)+[达尔文介亚目Darwinulocopina+巴氏介亚目Bairdiocopina]]]。  相似文献   

7.
姚戈  谢树莲 《植物学报》2007,24(2):141-146
串珠藻目(Batrachospermales)是淡水红藻中最主要的类群。近年来, 应用DNA序列分析探讨串珠藻目的系统发育, 并与传统的形态学和生态学特征相结合, 为串珠藻目系统学研究拓展了新的思路。本文回顾了串珠藻目的建立及其所含类群的研究历史, 归纳了目前在串珠藻目系统发育与进化研究中常用的分子标记方法, 其中包括核基因组的18S rDNA、26S rDNA和ITS序列, 叶绿体基因组的rbcL序列, 线粒体基因组的cox2-3序列, 以及新兴的ISSR技术, 并对各种分子标记的特点及适用范围做了评述。结果表明, ITS序列多适用于种群分化及相近种间遗传分析, ISSR标记适用于种下分类群间及同一种群不同个体间基因多态性分析, cox2-3序列在一定程度上也可用于同一种群不同个体间的基因多态性分析, 而18S rDNA 与rbcL序列既可用于种间关系分析, 又可用于更高水平分析的构建系统树。这些分子标记已被证明在研究串珠藻目系统地理、物种起源和散布机制方面有着广泛的应用前景。同时, 本文对串珠藻目分子系统学研究的最新进展也进行了概述,并对今后的研究方向做了展望。  相似文献   

8.
串珠藻目分子系统学研究进展   总被引:1,自引:0,他引:1  
姚戈  谢树莲 《植物学通报》2007,24(2):141-146
串珠藻目(Batrachospermales)是淡水红藻中最主要的类群。近年来,应用DNA序列分析探讨串珠藻目的系统发育,并与传统的形态学和生态学特征相结合,为串珠藻目系统学研究拓展了新的思路。本文回顾了串珠藻目的建立及其所含类群的研究历史,归纳了目前在串珠藻目系统发育与进化研究中常用的分子标记方法,其中包括核基因组的18SrDNA、26SrDNA和ITS序列,叶绿体基因组的rbcL序列,线粒体基因组的cox9.-3序列,以及新兴的ISSR技术,并对各种分子标记的特点及适用范围做了评述。结果表明,ITS序列多适用于种群分化及相近种间遗传分析,ISSR标记适用于种下分类群间及同一种群不同个体间基因多态性分析,cox2-3序列在一定程度上也可用于同一种群不同个体间的基因多态性分析,而18SrDNA与rbcLFF列既可用于种问关系分析,又可用于更高水平分析的构建系统树。这些分子枥对己已被证明在研究串珠藻目系统地理、物种起源和散布机制方面有着广泛的应用前景。同时,本文对串珠藻目分子系统学研究的最新进展也进行了概述,并对今后的研究方向做了展望。  相似文献   

9.
<正>莲(也称荷花)隶属莲科(Nelumbonaceae)莲属(Nelumbo),是被子植物家庭中起源较早的类群之一。最早化石出现在早白垩纪,第三纪时广布于北半球的众多湿地,共有5个化石属(Nelumbites、Paleonelumbo、Nelumbago、Exnelumbites和Nelumbo),约30个化石种。经过第四纪冰期后,仅现存一个莲属(Nelumbo),莲(N.nucifera Gaertn.)和美洲黄莲(N.lutea Willd.)2个种。莲分布于亚洲和澳大利亚北部,美洲黄莲分布于北美洲,二者被太平  相似文献   

10.
近五年,缅甸北部白垩纪中期克钦琥珀中相继发现了数百枚蜻蜓目化石,包含现生蜻蜓目三个亚目类群,目前已发表16科29属35种,在所有已知琥珀记录中数量和多样性最高。克钦琥珀中的蜻蜓目以均翅亚目(豆娘)为主,以Burmahemiphlebia zhangi最为常见,不少现生豆娘的化石记录也首次在克钦琥珀中发现,包括Perilestidae,Platycnemididae和Platystictidae等。此外,克钦琥珀中发现了一些中生代沉积岩中常见的蜻蜓目类群,如Araripegomphidae, Gomphaeschnidae和Stenophlebiidae等,指示克钦琥珀的时代可能为早白垩世晚期。这些发现为探讨蜻蜓目部分类群的起源、演化和揭示生物古地理提供了有力证据。  相似文献   

11.
The composition and structure of polysaccharides from several groups of calcareous algae (including calcareous cyanobacteria), which differ in the calcification mode (extracellular, cell wall, or intracellular), are reviewed. Two families of marine algae, Corallinaceae (Rhodophyta) and Coccolithophoraceae (Prymnesiophyta = Haptophyta), are considered in detail; they exhibit the cell wall and intracellular calcification modes, respectively, and synthesize unusual polysaccharides that seem to directly participate in the calcification process.  相似文献   

12.
The composition and structure of polysaccharides from several groups of calcareous algae (including calcareous cyanobacteria), which differ in the calcification mode (extracellular, cell wall, or intracellular), are reviewed. Two families of marine algae, Corallinaceae (Rhodophyta) and Cocolithophoraceae (Prymnesiophyta = Haptophyta), are considered in detail; they exhibit the cell wall and intracellular calcification modes, respectively, and synthesize unusual polysaccharides that seem to directly participate in the calcification process.  相似文献   

13.
长翅目昆虫在地史纪录上可以追溯到早二叠纪,是全变态昆虫中最原始的种类之一.截至目前,29篇关于中国长翅目昆虫化石分类的论著发表,共描述我国长翅目昆虫化石11科28属51种,这些化石分布于从三叠纪到白垩纪的不同地层中.本文通过图表提供了我国已发现的长翅目化石名录并介绍了其分布和年代,回顾了我国长翅目昆虫化石的研究进展,指出了一些分类存在的问题,简要慨述了长翅目中一些科的起源与演化以及长翅目与其它全变态昆虫的关系.我国长翅目化石种类丰富,但在基础分类、系统演化方面还缺乏系统的研究,因而许多工作甚至最基础的分类工作亟待开展.  相似文献   

14.
Abstract:  From 1935 to 1962 Maslov published two monographs and several other papers on the taxonomy of fossil calcareous algae of diverse ages from the large geographical area of the former USSR. Among many other taxa, he described five new genera ( Solenophyllum , Palaeophyllum , Mesolithon , Bicorium and Tomilithon , as a subgenus of Parachaetetes Deninger) which he attributed to the Corallinaceae, and the new genus Karpathia , which he included in the Squamariaceae. Type material of these taxa, except for Mesolithon , is housed in the Geological Institute of the Russian Academy of Sciences, Moscow. Re-examination of the genus types from a modern perspective of coralline algal taxonomy shows that Karpathia is a validly published genus of corallinaceans (subfamily Mastophoroideae) to which several Cenozoic fossil species can be assigned. In contrast, the holotype of P. elegans , the type species of Palaeophyllum , cannot be assigned to any subfamily within the Corallinaceae and its preserved features are inadequate for confidently delimiting a separate genus. Solenophyllum is a valid genus in which Palaeozoic representatives of Corallinales formerly attributed to Parachaetetes Deninger can be included. Tomilithon is considered a younger heterotypic synonym of Solenophyllum . The algal nature of the bioclasts in the type of Bicorium is uncertain.  相似文献   

15.
16.
Ordovician and Silurian coralline red algae   总被引:3,自引:0,他引:3  
Solenopora gotlandica Rothpletz, hitherto placed in the Solenoporaceae Pia, is locally common in the mid-Silurian of Gotland and Wales. It possesses small cells, radial monomerous thallus organization, trichocytes, and sporangia arranged in irregular sori. Solenopora gotlandica is not congeneric with S. spongioides , the type species of Solenopora. It closely resembles the extant coralline red alga Sporolithon Heydrich. S. gotlandica is here transferred to Craticula gen. nov., and Craticula is placed in the Craticulaceae fam. nov., which morphologically closely resembles the Mesozoic-Cenozoic family Sporolithaceae. The Craticulaceae is placed in the extant rhodophyte order Corallinales. Middle-Late Ordovician Petrophyton kiaeri Høeg resembles Late Ordovician Solenopora richmondense Blackwell et al. , which has sporangia in calcified compartments arranged in sori. These fossils may be craticulaceans. The apparent gap in the fossil record between Silurian Craticula and Cretaceous Sporolithon favours separation of these genera at family level. However, future work may demonstrate that the Craticulaceae is a junior synonym of the Sporolithaceae. Recognition of the Craticulaceae extends the earliest record of the Corallinales from Cretaceous to Silurian, and possibly Ordovician.  相似文献   

17.
By using TLC and GLC-MS techniques, 23 species of red algae, representing nine orders, were analyzed for the presence of simple bromophenols. Ten bromophenols were detected, five of which might be artefacts. Furthermore, lanosol was identified in sea water from the Polysiphonia Brodiaei—zone. Bromophenols were detected in species from the families Ceramiaceae, Delesseriaceae, Bonnemaisoniaceae, Rhodophyllaceae, Corallinaceae and Rhodomelaceae.  相似文献   

18.
The fine structure of pit plugs was examined in 63 species of red algae representing 34 families. The number of plug cap layers was found to be a taxonomically reliable character when tested against a recent revision of the Rhodymeniales which established the order Palmariales. In a broader survey involving all the orders of red algae possessing pit plugs, three basic plug cap configurations were detected. These differ in having one, two, or no plug cap layers. Some taxa have plug caps in which the outer cap layer is greatly elaborated, however, this layer was shown to be positionally and cytochemically identical, thus probably homologous, to the outer cap layer of the typical two-layered plug cap. The pit plug character confirms the validity of the order Palmariales and indicates that the Nemaliales and Cryptonemiales are heterogeneous assemblages. Revision of these groups along lines indicated by the plug character is supported by significant features of morphology and reproduction. These correlations lead us to propose that Rhodophysema and Coriophyllum be transferred to the Palmariales, that the Gelidiales be resurrected, that the Bonnemaisoniales (including the Naccariaceae) is deserving of recognition, that the Batrachospermaceae be raised to a higher rank which will also receive the Lemaneaceae and the Thoreaceae, and that the Corallinaceae and Hildenbrandiaceae both be raised to ordinal status.  相似文献   

19.
The wondrously diverse eukaryotes that constitute the red algae have been the focus of numerous recent molecular surveys and remain a rich source of undescribed and little known species for the traditional taxonomist. Molecular studies place the red algae in the kingdom Plantae; however, supraordinal classification has been largely confined to debate on subclass vs. class level status for the two recognized subgroups, one of which is widely acknowledged as paraphyletic. This narrow focus has generally masked the extent to which red algal classification needs modification. We provide a comprehensive review of the literature pertaining to the antiquity, diversity, and systematics of the red algae and propose a contemporary classification based on recent and traditional evidence.  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