Lake Tahoe vs. Lake Kinneret phytoplankton: comparison of long-term taxonomic size structure consistency     

Yury Kamenir  Monika Winder  Zvy Dubinsky  Tamar Zohary  Geoff Schladow 《Aquatic Sciences - Research Across Boundaries》2008,70(2):195-203

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匹配系数聚类分析在Pseudozaphrentis属分类中的应用   总被引：2，自引：0，他引：2  

王训练 《现代地质》1995,9(1):27-36

摘要：Ｐｓｅｕｄｏｚａｐｈｒｅｎｔｉｓ属分布广泛,有重要的地层意义,但关于其分类位置、范围及种的划分争论较大．本文在匹配系数统计分析的基础上,对Ｐｓｅｕｄｏｚａｐｈｒｅｎｔｉｓ属的下列３个方面予以讨论：１．探讨属之间的亲缘关系,确定属的分类位迂．Ｐｓｅｕｄｏｚａｐｈｒｅａｔｉｓ与相近属的对比表明其与Ｃｈａｒａｃｔｏｐｈｙｌｌｕｍ－属的匹配系数最高,它们之间的关系可能最为相近．因此把二者归入属以上的同一最低分类单元—Ｃｈａｒａｃｔｏｐｈｙｌｌｉｎａｅ亚科．２．确定属的范围．根据统计结果得到的代表性特征组简单而准确地定义属．３．合理地划分种．Ｐｓｅｕｄｏｚａｐｈｒｅａｔｉｓ－属可分为４个种：ＰｓｅｕｄｏｚａｐｈｒｅｎｔｉｓｄｉｆｆｉｃｉｌｅＳｕｎ,１９５８１;ＮｅｏｓｔｒｉｎｇｏｐｈｙｌｌｕｍｐｒｏｎｉｎｉＳｏｓｈｋｉｎａ,１９５１;Ｐｓｅｕｄｏｚａｐｈｒｅｎｔｉｓｃｆ．ｗａｎｇｃｈｅｎｐｏｅｎｓｉｓＹｕｅｔＬｉａｏｉｎＪｉｎｅｔａｌ．,１９８２;ＰｓｅｕｄｏｚａｐｈｎｙｔｉｓｘｉｐｉｎｇｓｈａｎｅｎｓｉｓＸ．Ｌ．Ｗａｎｇ,１９８７．  相似文献   

New Cretaceous Scoliidae (Vespida=Hymenoptera) from the Lower Cretaceous of Spain and Brazil     

A. P. Rasnitsyn  X. Martínez-Delcls 《Cretaceous Research》1999,20(6):767

A new genus, Cretaproscolia, and three new species of scoliid wasps, Archaeoscolia hispanica, Cretoscolia montsecana and Cretaproscolia josai, are described from the Lower Cretaceous of Spain and Brazil. The species representing the new genus is attributed to the plesiomorphic extant subfamily Proscoliinae, while the two other new species are assigned to two previously described genera in the extinct, archaic subfamily Archaeoscoliinae. The Brazilian species is the first Mesozoic scoliidid to have been described from the New World.  相似文献   

Aeschnidiid nymphs from the Jehol biota (latest Jurassic–Early Cretaceous), China, with a discussion of the family Aeschnidiidae (Insecta, Odonata)     

Junfeng Zhang 《Cretaceous Research》1999,20(6):813

Undoubted fossil nymphs of the family Aeschnidiidae within the Aeschnidioidea of the Anisoptera, Odonata are identified and described and their phylogenetic relationship and bioecological characteristics are deduced. The nymphs discovered previously in China, Mongolia and Russia and considered to be aeschnidiids are, in fact, unrelated to this group. All nine Chinese species in six genera can be merged into one alone, Aeschnidium heishankowense. It is the first animal from the ‘Jehol biota’ of East Asia to be linked with the species known from the Lower Tithonian of Germany. The geological age of the oldest strata bearing the fossil nymphs is debatable; it could be latest Jurassic rather than Early Cretaceous.  相似文献   

浮游藻类三个常见属(颤藻属、直链硅藻属和针杆藻属)学名变更的解释   总被引：4，自引：3，他引：1  

陈宇炜  李朋富  MartinDOKULIL 《湖泊科学》2003,15(1):85-94

根据近年来国外文献所涉及的藻类分类学研究进展,着重解释了蓝藻门的颤藻属和硅藻门的直链硅藻属和针杆藻属的一些浮游种类的学名变更情况,同时介绍了国际上最新的蓝藻门颤藻目和硅藻门的分类概况．根据Anagnostidis和Komfirek的分类,原颤藻属的大部分浮游种类进入了新属『浮游蓝丝藻属](Planktothrix),其他种类则分别属于[湖生蓝丝藻属](Limnothrix)、胶鞘藻属(Phormidium)和现在的颤藻属(Oscillatoria)等多个颤藻目的类别．根据Krammer和Lange-Bertalot的分类,原直链硅藻属的浮游种类进入了新属[浮生直链藻属](Aularoseira),另外的种类归属于Orthoseira、Ellerbeckia和现在的直链硅藻属(Melosira)等硅藻类别中：原针杆藻属的浮游种类并入脆杆藻属(Fragilaria),其他种类进入菱形藻属(Nitzschia)、双尖菱板藻属(Hantzschia)和现在的针杆藻属(Synedra)中．  相似文献   

Fish and ostracod remains from the Santos Basin (Cretaceous to Recent), Brazil     

C. Giles Miller  Martha Richter  Dermeval A. Do Carmo 《Geological Journal》2002,37(4):297-316

For the first time, ichthyoliths are described from the Santos sedimentary basin, offshore southern Brazil. Isolated teeth, dermal scales and the first documented otoliths from Cretaceous (Albian) to Recent cuttings from five wells are described. The following groups are represented: Chondrichthyans: Triakidae, Carcharhinidae; Ginglymostomatidae: ?Ginglymostoma sp., Lamnidae indet., Scyliorhinidae; Osteichthyans: Teleostei; Myctophiidae: Diaphus aff. splendidus sp. complex, Diaphus spp., Diaphus cf. garmani, Ceratoscopelus aff. warmingii; Sternoptychidae: Valenciennellus tripunctulatus, teeth of indeterminate Teleostei. The majority of these ichthyofossils represent extant forms, known to occur in the Atlantic Ocean, and are of potential value for stratigraphical correlations between oil‐yielding basins in the region. Ostracods are not well preserved but can be identified to generic level indicating marine environments. The ostracod faunas offer potential for intrabasinal correlation in the Eocene and Oligocene. Copyright © 2002 John Wiley & Sons, Ltd.  相似文献   

Demographic history,range size and habitat preferences of the groundwater amphipod Niphargus puteanus (C.L. Koch in Panzer, 1836)     

《Limnologica》2020

Niphargus puteanus is the oldest described species of its genus and, in the past, was used as a taxonomic annotation for any subterranean amphipod record. For that reason, no clear knowledge exists about its actual range size and habitat preferences. We here applied a molecular taxonomic and phylogeographical approach based on mitochondrial and nuclear DNA to shed light on its distribution and to infer its demographic history. Furthermore, we analysed aquifer types and water flow regimes to provide a clearer picture of the species’ ecological requirements.Our results indicate that N. puteanus is widely distributed north of the Alps, having its core range in the geomorphological natural region of the ‘South German Scarplands’ (SGS). Additionally, isolated satellite populations exist in the Taunus and the Sauerland, and two single individuals were collected in Luxembourg and in Austria, respectively. The species’ maximal distribution range reaches 756 km between the two single-specimen records and 371 km within the SGS. A very high haplotype diversity was observed, revealing the presence of seven haplotype groups. All the haplogroups were present in the SGS and exhibited distinct spatial-genetic patterns. We thus inferred a high degree of population isolation, with the SGS being a potential long-term refugium for N. puteanus. Historical drift of specimens along major riverine networks (Rhine, Danube) may provide an evolutionary dispersal mechanism explaining the formation of satellite populations.From an ecological perspective, populations of N. puteanus were found to be closely associated with fast-flowing spring environments within fissured aquifers. This species should therefore be classified as both crenophile and stygophile, effectively exploiting resources of surface as well as subsurface spring waters.  相似文献   

Late Silurian (Ludlow–Přídolí) microfossils and sedimentation in the Welsh Basin near Clun,Shropshire     

C. Giles Miller  Stuart J. E. Sutherland  Ken J. Dorning 《Geological Journal》1997,32(1):69-83

The base of the Clun Forest Formation at Clun, Shropshire, has previously been taken to correlate with the base of the Downton Castle Sandstone Formation (Přídolí Series, upper Silurian) on the basis of brachiopod, bivalve, gastropod and ostracod faunas. The detailed distribution of microfossils (acritarchs, chitinozoans, conodonts and ostracods) is documented at Nantyrhynau Quarry, Clun, Shropshire, to test this correlation. Three new species of chitinozoans, Eisenackitina clunensis, Eisenackitina kerria and Angochitina paucispinosa, are described from the quarry. Macrofossil and ostracod distributions suggest that the correlation is correct. However, a typical Ludlow acritarch flora is present throughout the section and suggests that the basal part of the Clun Forest Formation is Ludlow in age. The mixture of characteristic Ludlow and Přídolí microfossils at Nantyrhynau Quarry may be the result of differing environmental conditions between the Ludlow (shelf) and Clun (basinal) areas at this time. Alternatively, the strata exposed at Nantyrhynau Quarry may represent a period towards the end of the Ludlow Series when there are no strata represented in corresponding shelf sections due to non-deposition or erosion. © 1997 John Wiley & Sons, Ltd.  相似文献   

Redescription and taxonomic reconsideration ofNemertopsis gracilis var.bullocki Coe, 1940     

Sun Shi-chun  Dong Shuang-lin 《中国海洋湖沼学报》1998,16(3):271-279

Specimens ofNemertopsis gracilis var.bullocki Coe, 1940 collected from Huian, Fujian Province, China, are described. The variety is upgraded to specific level on the basis of: the dorsal surface having a pair of blackish brown longitudinal stripes meeting anteriorly with a broad transverse band of the same color; the proboscis having 11–13 distinct proboscis nerves in its longitudinal muscle layer. Project 39170111 and 39470097 supported by NSFC.  相似文献   

胶州湾自由生活线虫Wieseria属的两个新种     

黄冕  孙静  黄勇 《海洋学报(英文版)》2018,37(10):157-160

文章描述了采自青岛胶州湾潮下带沉积物中自由生活线虫Wieseria属的两个新种。新种Wieseria sinica sp.nov.特征为具有短的唇刚毛和头刚毛，且指向后方；具有椭圆形双边化感器；弓形的交接刺具有翼膜；环状的引带以及棒状尾。新种Wieseria tenuisa sp.nov.特征为具有大的德曼值（133.6）；长的唇刚毛指向前方；交接刺具有翼膜，近端呈钩状；引带呈棒状；具有相当长的棒状尾（长度相当于7.9倍泄殖腔相应体径）。它区别于新种Wieseria sinica sp.nov.主要在于更长的唇刚毛，且指向前方；交接刺相对较直且具有钩状近端，身体更加细小（德曼“a”值较大）。文章更新完善了的Wieseria属的二岐检索表。  相似文献