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1.
运用分支分类学方法对天南星属进行了系统发育分析,以天南星属13个组为13个分支分类单位,选择菖蒲属作为外类群,从天南星属植物特征中选取13个性状作为建立数据矩阵的基本资料,并以外类群比较和通行的形态演化规律为依据这些性状进行极化,采用改进后的最大同步法和最小平行进化法进行分类运算,按照最简约的原则,选出演化长度较短的最大同步法谱分支图,作为本文讨论的基础,并在此基础上,探讨了天南星属各组的系统关系。  相似文献   

2.
瘿绵蚜科系统发育研究(同翅目:蚜总科)   总被引:1,自引:0,他引:1  
张广学  陈小琳 《昆虫学报》1999,42(2):176-183
采用支序分析的方法对瘿绵蚜科的系统发育进行了探讨。研究结果表明,传统的倍蚜族Schlechtendalini、五节根蚜族Fordini和瘿绵蚜族Pemphigini 是单系群,传统的 卷叶绵蚜族Prociphilini 和四脉绵蚜族Tetraneurini是并系群。在瘿绵蚜科的三个亚科中,瘿绵蚜亚科与五节根蚜亚科亲缘关系比与绵蚜亚科更近。另外,根据支序分析结果,建议将丽绵蚜属Formosaphis从瘿绵蚜亚科移入五节根蚜亚科中。  相似文献   

3.
    
Titanosauriformes was a globally distributed, long‐lived clade of dinosaurs that contains both the largest and smallest known sauropods. These common and diverse megaherbivores evolved a suite of cranial and locomotory specializations perhaps related to their near‐ubiquity in Mesozoic ecosystems. In an effort to understand the phylogenetic relationships of their early (Late Jurassic–Early Cretaceous) members, this paper presents a lower‐level cladistic analysis of basal titanosauriforms in which 25 ingroup and three outgroup taxa were scored for 119 characters. Analysis of these characters resulted in the recovery of three main clades: Brachiosauridae, a cosmopolitan mix of Late Jurassic and Early Cretaceous sauropods, Euhelopodidae, a clade of mid‐Cretaceous East Asian sauropods, and Titanosauria, a large Cretaceous clade made up of mostly Gondwanan genera. Several putative brachiosaurids were instead found to represent non‐titanosauriforms or more derived taxa, and no support for a Laurasia‐wide clade of titanosauriforms was found. This analysis establishes robust synapomorphies for many titanosauriform subclades. A re‐evaluation of the phylogenetic affinities of fragmentary taxa based on these synapomorphies found no body fossil evidence for titanosaurs before the middle Cretaceous (Aptian), in contrast to previous reports of Middle and Late Jurassic forms. Purported titanosaur track‐ways from the Middle Jurassic either indicate a substantial ghost lineage for the group or – more likely – represent non‐titanosaurs. Titanosauriform palaeobiogeographical history is the result of several factors including differential extinction and dispersal. This study provides a foundation for future study of basal titanosauriform phylogeny and the origins of Titanosauria. © 2012 The Linnean Society of London, Zoological Journal of the Linnean Society, 2012, 166 , 624–671.  相似文献   

4.
    
In this paper we carry out a taxonomic revision and phylogenetic analysis of the linyphiid spider genus Solenysa Simon, 1894. A total of 12 species is treated here, including five new species collected from China and Japan: Solenysa akihisai Tu sp. nov., Solenysa lanyuensis Tu sp. nov., Solenysa retractilis Tu sp. nov., Solenysa tianmushana Tu sp. nov. , and Solenysa yangmingshana Tu sp. nov. Solenysa circularis Gao, Zhu & Sha, 1993 is a junior synonym of Solenysa protrudens Gao, Zhu & Sha, 1993. We have assembled two different character matrices to reconstruct the phylogenetic relationships of Solenysa. In the first matrix (Matrix 1), five representative species of Solenysa were added to the morphological dataset of Miller & Hormiga to test the monophyly of the genus and its placement within Linyphiidae. The genitalic structures and somatic morphology of Solenysa were studied by means of scanning electron microscopy for the first time. To infer the species‐level phylogenetic relationships of Solenysa we produced a second matrix (Matrix 2) that includes all 12 Solenysa species and six outgroup species chosen from the results of the analysis of the first matrix. The two most parsimonious trees from the analysis of Matrix 1 support the monophyly of Solenysa and its placement within the ‘Distal Erigonines’ clade. The single most parsimonious tree resulting from the analysis of the second matrix suggests that the Solenysa clade includes four monophyletic groups, each group represented by a distinct genitalic pattern. The morphology of Solenysa, both somatic and genitalic, is highly autapomorphic. © 2011 The Linnean Society of London, Zoological Journal of the Linnean Society, 2011, 161 , 484–530.  相似文献   

5.
    
The relationships among basal sauropodomorphs are controversial. Results of cladistic analyses vary from a fully paraphyletic assemblage to a monophyletic core‐prosauropod. We apply the comparative cladistics method to three published cladistic analyses of sauropodomorph dinosaurs, in order to identify root causes for differences between phylogenetic results. Except for three taxa (Saturnalia, Thecodontosaurus, and Efraasia) and one clade (Gravisauria), the remaining genera are recovered with conflicting positions. The comparative method is based on indices that allow for the quantification of the degree of similarity in characters and character states among analyses. A comparison of primary data, character selection, and scoring highlights significant discrepancies in data sets. Our results suggest that one character out of two varies from one analysis to the other. These are the root causes for the phylogenetic incongruence observed. The hurdle of the phylogenetic definition of the clade Sauropoda, which has been defined in four different ways, is also treated. We concur with several recent papers following the first node‐based definition of Sauropoda. © 2015 The Linnean Society of London  相似文献   

6.
选取形态及胚胎学特征,采用支序分析的方法对跳蚜亚科的系统发育进行了探讨。研究结果表明,Allaphis应作为蓟马蚜属Thripsaphis的一个亚属,Peltaphis应作为独立的属存在。Stenaphis应作为亚跳蚜属Subsallusaphis的一个亚属,粗腿蚜属Macropodaphis应建立一个新的亚科,该新亚科建议为粗腿蚜亚科Macropodaphinae。蓟马蚜属和毛斑蓟马蚜属Trichocallis为一对姐妹群,并且为较原始的类群。田鼠尾跳蚜属Sminhuraphis为单系类群,并与蓟马蚜属和毛斑蓟马蚜属具有共同的起源。聂跳蚜属Neveskyella和依跳蚜属Iziphya为一对姐妹类群,它们与跳蚜属Saltusaphis具有共同的祖先。亚跳蚜属与聂跳蚜属、依跳蚜属和跳蚜属有共同的起源,但较后三者原始。所有属之中,依跳蚜属相对较为进化。  相似文献   

7.
Abstract Phylogenetic analysis of Saltusaphidinae (Homoptera: Aphidoidea: Drepanosiphidae) was made by using 10 generic, 17 adult and 2 embryo characters. The results suggest alternative hypotheses: (1) Allaphis should be a subgenus of Thripsaphis; (2) Peltaphis should be an independent genus; (3) Stenaphis should be a subgenus of Subsaltusaphis; (4) monophyly of Sminthuraphis; and (5) phylogenetic relationships of Neveskyella, Subsaltusaphis, Saltusaphis and Iziphya. In order to resolve the argued position of Macropodaphis Remaudiere and Davatchi, 1958, Phyllaphidinae, Saltusaphidinae and Macropodaphis were taken as in-group members, 6 morphological characters and host-plant character were used. The result shows that Macropodaphis should be in a new subfamily Macropodaphidinae, and Macropodaphidinae and Saltusaphidinae should be sister groups.  相似文献   

8.
9.
    
The Anopliidae is one of the most diverse families in the brachiopod suborder Chonetidina. All previous attempts to work out the phylogeny and taxonomy of this family assume that the group is monophyletic. Great phylogenetic significance has been placed on the presence or absence of a single key feature, such as radial external ornament or accessory lateral septa of the brachial valve. In order to evaluate previous classifications of the family and the characters on which they are based, we performed a cladistic analysis of 23 anopliid taxa, two outgroup taxa, Rugosochonetes and Waagenites and three problematic taxa, Trichochonetes, Airtonia and Davoustia whose inclusion within the Anopliidae has been controversial. A single most parsimonious tree was obtained, with a length of 157, CI=0.28 and RI=0.47. The results do not support previous bipartite divisions of the family. In addition, the analysis is inconsistent with the presumption of monophyly for this family. Rather, it supports restriction of the Anopliidae to a clade united by small adult length, removing several large taxa from the family and confirming the non‐anopliid status of Airtonia and Davoustia.  相似文献   

10.
石蒜属植物分支系统学分析   总被引:10,自引:0,他引:10  
邓传良  周坚 《植物研究》2005,25(4):393-399
基于37个形态学、解剖学、孢粉学和细胞学性状及解剖学性状之外的28个形态学、孢粉学和细胞学性状,分别对石蒜属进行分支系统学分析,试图建立石蒜属种间的系统发育关系。利用PAUP*软件分别构建了最大简约树(MP),所得树的拓扑结构是一致的。同时,基于解剖学9个性状,对石蒜、换锦花、忽地笑、江苏石蒜、长筒石蒜、乳白石蒜、夏水仙、红兰石蒜、安徽石蒜、短蕊石蒜、中国石蒜11个种进行系统发育树构建,其结果也是支持上述系统发育树的。系统发育树结构结果表明,石蒜属16种明显聚为两大类:石蒜、玫瑰石蒜、稻草石蒜和江苏石蒜;广西石蒜、红兰石蒜、换锦花、香石蒜、夏水仙、长筒石蒜、安徽石蒜、中国石蒜、忽地笑、乳白石蒜、短蕊石蒜和陕西石蒜。除换锦花、红兰石蒜及江苏石蒜系统发育位置不同之外,大类群的划分与RAPD指纹图谱基本一致。类群一均属于石蒜亚属(Lycoris亚属)。类群二又可以聚为两小类:广西石蒜、红兰石蒜、换锦花、香石蒜、夏水仙归为一类;长筒石蒜、安徽石蒜、中国石蒜、忽地笑、乳白石蒜、短蕊石蒜和陕西石蒜归为一类。前一子类群除广西石蒜外,都属于整齐花亚属(Symman thus亚属)。后一子类群除长筒石蒜与安徽石蒜外,均属于石蒜亚属(Lycoris亚属)。因此,花冠整齐与否是一个重要的分类特征,但作为石蒜属植物亚属的划分依据,没有得到本研究支持。而在本文中,雄蕊与花被片的位置关系可以作为大分类群划分依据,能否依此来对石蒜属植物亚属进行划分,仍需探讨。另外研究表明叶微形态特征在研究种间亲缘关系时,具有一定的作用。而在种间亲缘关系鉴定时,出叶期不应成为重要的依据。同时研究还表明中国石蒜与忽地笑具有非常近的亲缘关系,与形态学研究一致。  相似文献   

11.
Freshwater crab sister group relationships with marine eubrachyuran families were investigated. A morphology-based cladistic analysis was conducted on representatives of the freshwater crab families Deckeniidae, Gecarcinucidae, Parathelphusidae, Potamidae, Potamonautidae, Pseudothelphusidae, and Trichodactylidae using a disparate assemblage of marine heterotreme and thoracotreme brachyurans as possible sister groups. The monophyly of the freshwater crabs sensu lato is falsified. The family Trichodactylidae and the marine portunid subfamily Carcininae form basal groups within the superfamily Portunoidea. The monophyly of the Pseudothelphusidae and the Paleotropical freshwater crab families is supported, and this clade is the sister group of the Thoracotremata (Gecarcinidae, Grapsidae s.l., and Ocypodoidea). The origin, groundplan, and diversification of freshwater crabs are discussed in the context of previously published scenarios of their evolution.  相似文献   

12.
Scale and squamation characters have proved to be useful in investigating phyletic relationships in the family Cichlidae. To provide a sound basis for a cladistic analysis the plesiomorphic states have to be determined. This has been done for the family as a whole as well as for some phyletic lineages. Based on those characters the phylogeny within the family has been investigated.  相似文献   

13.
A cladistic analysis of phylogenetic relationships is carried out for the feather mite subfamily Avenzoariinae. The analysis is made at two different taxonomic levels, for 19 genera of the all family Avenzoariidae and for taxa of species rank for the Avenzoaria and Bychovskiata generic groups. A subsequent comparative analysis of phylogenetic hypotheseis for the subfamily Avenzoariinae and recently accepted phylogenetic hypotheses of the shorebirds Charadriiformes indicates co-speciation of feather mites with their hosts. As a result of the comparative analysis it is suggested, that the subfamily Avenzoariinae originated from an ancestor of the order Charadriiformes and co-speciated with this host order. The expected pattern of parallel evolution is disturbed by different evolutionary events, such as host shifts, extinction of mites and differential evolutionary rates of mite lineages in different phyletic branches of feather parasites.  相似文献   

14.
Resemblance between animal taxa may be due to convergence rather than to recent common ancestry. Constraints on biological materials and adaptation to particular habits or habitats will produce widespread convergence. How may we distinguish the two causes of resemblance? The relationship between convergence and taxonomy is discussed, demonstrating that the choice of taxonomic method will itself determine the extent to which convergence is perceived. In particular, cladistic analysis based on parsimony will tend to minimise and thus conceal convergence: neither the resulting cladogram nor a consistency index derived from it can be used to assess the prevalence of convergence. With any taxonomic system, there can be no substitute for evaluation of the morphological characters used. Complementary use of molecular characters shows promise: we wait further understanding of constraints in genetic evolution and of the possibilities of convergence at this level also. These general principles are illustrated with a range of examples from within and between invertebrate phyla: the phylogeny of Cnidaria and Platyhelminthes cannot be traced with certainty, but where the fossil record allows clear rooting, as for the echinoderms and in particular the echinoids, combination of morphological and molecular methods has made much progress. Sub-groups within a phylum, for example opisthobranch molluscs and the dipteran Phoridae, may show an uncontested phylogeny, and here studies have precisely identified convergence and shown that it may be the commoner cause of resemblance. Adaptation to exacting environments shown by terrestial and freshwater nemertines may also result in a predominance of convergent resemblance. Traditional grouping of phyla breaks down on re-examination of supposedly key characters, such as segmentation, body cavities, germ layers and symmetry, each of which must have had multiple origins: nor are developmental stages (especially not larvae) a reliable guide to relationships. Demarcation of phyla may be difficult, as with arthropods, and location of phyla is even more difficult, due to their early and rapid radiation. Over-simplified definition of characters has bedevilled invertebrate classification and the use of molecular data has not yet resolved the major controversies. The question ‘How common is convergence?’ remains unanswered and may be unanswerable. Our examples indicate that even the minimum detectable levels of convergence are often high, and we conclude that at all levels convergence has been greatly underestimated.  相似文献   

15.
The six-eyed pholcid spiders of East Africa are revised. A new genus is recognized, Buitinga n. gen ., with 17 new species and three species transferred from Spermophora Hentz. The new genus is characterized by the presence of a scape on the epigynum. This scape may be straight or tightly curled up at rest, and is usually highly expandable. Seven additional African and Comoran species are newly described and tentatively assigned to Spermophora . A data matrix with 60 characters and 77 taxa (including 20 East African species and 25 additional Spermophora and ' Spermophora -like' species) is analysed cladistically. Buitinga is closer to the genera Paramicromerys Millot (endemic in Madagascar) and Spermophorides Wunderlich (Mediterranean and Canary Islands) as well as to several African and Comoran species tentatively assigned to Spermophora than to the type species of Spermophora . It is argued that current estimates of species numbers may be inaccurate and that pholcids may turn out to be one of the most diverse spider families.  © 2003 The Linnean Society of London. Zoological Journal of the Linnean Society, 2003, 137, 555−619  相似文献   

16.
采用Hennig 86程序,以柄菌蚊科和喙菌蚊科代表种为外群,选取48个特征,使用mhen-nig^*和bb^*指令在586微机上运算,首次对菌蚊科中5亚科28属的28种进行支序分析,探讨各分类单元系统发育关系。结果表明:菌蚊亚科与滑菌蚊亚科的亲缘关系较近,二者互为姐妹群,粘菌蚊亚科属于原始类群;菌蚊亚科为5个亚科中的进化类群;邻菌蚊亚科可能为并系群;真菌蚊亚科是介于邻菌蚊亚科与菌蚊亚科之间的类群。  相似文献   

17.
Phylogeny of turacos (Aves, Musophagidae). Analysis of morphological characters
A cladistic analysis of the 23 species of turacos (Musophagidae) using 34 morphological characters produces, after successive weighting, 4 shortest-length trees (consistency index = 0.76) that present two major clades: the first one with 'grey' turacos (genus Crinifer, Corythaixoides ), the other one with the great blue turaco (genus Corythaeola ) and the turacine bearers turacos (genus Tauraco , Musophaga , Ruwenzorornis , Gallirex ). This result also suggests that the species ' persa ' is not valid; T. schalowi , T. livingstonii , T. corythaix which were included in this species are more closely related to T. fisheri and T. schuettii than they are to T. persa . The polymorphism of these green turacos is also discussed. Ruwenzorornis johnstoni and Gallirex porphyreolophus do not belong to the Tauraco clade nor to the Musophaga clade, but they are closer to the first than to the second. The species Corythaixoides leucogaster is closer to the Crinifer species than to the other Corythaixoides species.  相似文献   

18.
    
We present new material of the selenodont anthracothere Hemimeryx blanfordi from the Oligocene deposits of the Bugti Hills (Balochistan, Pakistan), collected between 1999 and 2002. This is the first undisputed Oligocene occurrence of the species, previously known from the early Miocene of Pakistan. Investigation of the molar enamel microstructure reveals a surprising mono-zonal Schmelzmuster, already detected in some middle to Late miocene selenedont anthracotheres. We include this observation combined with a morphological revision of H. blanfordi and a cladistic assessment of the dental evidence, to propose a new phylogenetic hypothesis regarding Hemimeryx and its close relatives. We confirm the clade including advanced bothriodontines, which we erect to a tribe rank and name Merycopotamini. The South Asian origin of Merycopotamini is consistent with hypothesized subsequent dispersal events of Merycopotamini from Asia to Africa.  相似文献   

19.
Cladistic analysis of nuclear-encoded rRNA sequence data provided us with the basis for some new hypotheses of relationships within the green algal class Ulvophyceae. The orders Ulotrichales and Ulvales are separated from the clade formed by the remaining orders of siphonous and siphonocladous Ulvophyceae (Caulerpales, Siphonocladales /Cladophorales [S/C] complex, and the Dasycladales), by the Chlorophyceae and Pleurastrophyceae. Our results suggest that the Ulvophyceae is not a monophyletic group. Examination of inter- and intra-ordinal relationships within the siphonous and siphonocladous ulvophycean algae revealed that Cladophora, Chaetomorpha, Anadyomene, Microdictyon, Cladophoropsis and Dictyosphaeria form a clade. Thus the hypothesis, based on ultrastructural features, that the Siphonocladales and Cladophorales are closely related is supported. Also, the Caulerpales is a monophyletic group with two lineages; Caulerpa, Halimeda, and Udotea comprise one, and Bryopsis and Codium comprise the other. The Dasycladales (Cymopolia and Batophora) also forms a clade, but this clade is not inferred to be the sister group to the S/C complex as has been proposed. Instead, it is either the sister taxon to the Caulerpales or basal to the Caulerpales and S/C clade The Trentepohliales is also included at the base of the siphonous and siphonocladous ulvophycean clade. The Pleurastrophyceae, which, like the Ulvophyceae, posses a counter-clockwise arrangement of flagellar basal bodies, are more closely related to the Chlorophyceae than to the Ulvophyceae based on rRNA sequences. Thus, the arrangement of basal bodies does not diagnose a monophyletic group. Previously reported hypotheses of phylogenetic relationships of ulvophycean algae were tested. In each case, additional evolutionary steps were required to obtain the proposed relationships. Relationships of ulvophycean algae to other classes of green algae are discussed.  相似文献   

20.
The leaf, stem, root, tuber and dropper anatomy of the orchid tribe Diseae (including the subtribes Satyriinae, Disinae, Brownlecinac, Huttonaeinae and Coryciinae) is reviewed. The study is largely based on investigations of 123 species, and data from several previous publications have also been incorporated. Two characters were identified as being taxonomically valuable: (1) the presence of sclerenchyma caps associated with leaf vascular bundles, and (2) the degree of dissection of the siphonostele of the tuber (‘polystelic’ or ‘monostelic’). The phylogenetic analysis shows that anatomical characters do not change the basic structure of a cladogram that is based on morphological characters. The taxa of Diseae are discussed on the basis of anatomical data. Subtribes Satyriinae (excluding the anatomically unusual genus Pachites), Brownleeinae, Huttonaeinae, and Coryciinae are uniform in. critical anatomical characters. However, subtribe Disinae is rather diverse in vegetative anatomy. Disa sect. Micranthae differs from the rest of the genus in its leaf anatomy. The occurrence of foliar sclerenchyma bundle caps and ‘polystelic’ tubers supports the incorporation of Herschelianthe in Disa sect. Stenocarpa.  相似文献   

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