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1.
The sepiids are characterized by their cuttlebone or sepion, an internal shell resulting from secondary mineralization of a chitinous 'gladius'. The various species are identified using a combination of shell criteria and 'soft-part' characters. Using mitochondrial genes, we established phylogenetic relationships of sepiids including the three accepted genera ( Sepia , Sepiella , Metasepia ) and a species complex of uncertain status ( Doratosepion ). We showed the Sepia genus to be paraphyletic and found no direct correlation between geographical distribution and systematics. We mapped, on the molecular tree, shell characteristics commonly used as reliable diagnostic criteria for taxonomy. Due to the plasticity of the shell, these characters did not appear phylogenetically informative. In an attempt to define systematic categories related to phylogenetic relationships, new clear synapomorphies need to be established for each genus, necessitating a revision of the genus Sepia .  © 2006 The Linnean Society of London, Biological Journal of the Linnean Society , 2006, 89 , 139–150.  相似文献   

2.
Species-level phylogeny of the Butterfly tribe Argynnini is established based on 141 characters derived from wing and genitalia morphology of both sexes. The Argynnini can be divided into three subtribes; Yrameina comprising Yramea and Boloria s . l ., Argynnina comprising Prokuekenthaliella , Issoria , Brenthis , and all the 'large fritillary' species joined in the genus Argynnis s . l . and a new subtribe Euptoietina comprising only the genus Euptoieta . The classical genus Issoria s . l . is polyphyletic regarding Yramea and possibly paraphyletic regarding the two Afrotropic species baumanni and hanningtoni ; these two species are tentatively transferred to the old genus/subgenus Prokuekenthaliella . Surprisingly, one Afrotropic species, Issoria smaragdifera is closely related to the East Palaearctic Issoria species. A revised classification of Argynnini is proposed based on the obtained phylogeny. Studies of larval host plants based on the obtained phylogeny suggest that the ancestral Argynnini used Passiflora and Violaceae, but already the ancestor of Yrameina + Argynnina was probably specialized on Violaceae. Whereas the Boloria species have turned to other food plants such as Dryas , Vaccinium and Salix on several occasions, only Brenthis among the Argynnina use other host plants than Viola (mainly Rosaceae). The habit of laying eggs away from the food plant has probably evolved twice within Argynnina.  © 2006 The Linnean Society of London, Biological Journal of the Linnean Society , 2006, 89 , 627–673.  相似文献   

3.
Cerdia is a poorly understood genus of minute cushiony plants endemic to Mexico that is traditionally placed in subfamily Paronychioideae, tribe Polycarpeae (Caryophyllaceae). Morphological observations and phylogenetic analysis of ITS DNA sequences were carried out to determine the number of species, heretofore controversial, that constitute the genus as well as its position within Caryophyllaceae. Samples of Cerdia were collected through its entire range of distribution and together with previous specimens were used in morphological analyses. Nineteen terminal taxa were considered in a phylogenetic analysis with representatives of the different lineages in Caryophyllaceae. Results indicated that Cerdia is a monotypic genus, including only one variable species, C .  virescens , but its phylogenetic affinities remain doubtful.  © 2006 The Linnean Society of London, Botanical Journal of the Linnean Society , 2006, 152 , 1–13.  相似文献   

4.
A new species of Cephalocarida belonging to the genus Lightiella is described. Like all known species of Lightiella , the new species is characterized by reduction of trunk segment 8, which also lacks both pleura and thoracopods. The diagnostic characters of the species are: (1) one seta on the inner distal corner of the penultimate endopodal segment of second maxilla and thoracopods 1–5; (2) only one claw on the distal segment of the endopod of thoracopod 6. A cladistic analysis of 27 morphological characters was used to estimate the phylogeny of all species of Lightiella , with all other cephalocarid species used as outgroups. The discovery of this species in the Mediterranean fills a gap in the distribution of the genus and of the entire class.  © 2006 The Linnean Society of London, Zoological Journal of the Linnean Society , 2006, 148 , 209–220.  相似文献   

5.
6.
Section Choretropsis genus Phyllanthus (Euphorbiaceae) is formed by plants whose branches are modified into phylloclades. Despite the suitable characteristics of phylloclades within the Phyllanthus genus, the systematics of these species are poorly understood. Morphological data are presented here to allow future revision of this taxonomic group. The section is represented by nine species distributed in South America, eight of them endemic to Brazil. Our taxonomic studies distinguish the species and propose the synonymization of nine varieties of P. klotzschianus and two varieties of P. flagelliformis based on vegetative and reproductive characters. The diversity of branching and the morphology of phylloclades are discussed.  © 2006 The Linnean Society of London, Botanical Journal of the Linnean Society , 2006, 150 , 131–164.  相似文献   

7.
The woodpecker genus Veniliornis comprises 12 species, all restricted to the New World tropics. The seemingly distantly related genus Picoides is broadly distributed in Eurasia and North America with two putative species, P. lignarius and P. mixtus , occurring in South America. The two genera are clearly distinct with respect to general plumage colouration and patterning as well as habitat utilization and thus traditionally have been placed in different tribes. Phylogenetic analyses of mtDNA sequences from the COI and cyt b genes indicated that both genera are reciprocally paraphyletic. The two South American species of Picoides belong to a clade comprising most species of Veniliornis , but V. fumigatus of Central and north-western South America belongs to a clade comprising species of Picoides . The mtDNA tree also indicated that Veniliornis is not closely related to the genus Piculus, as is implicit in current classifications. Misclassifications involving Veniliornis at both the generic and tribal levels appear to result from convergent evolution of plumage traits in specific forest types. We infer that the common ancestor of Veniliornis entered South America approximately at the time the Isthmus of Panama was formed, and diversification within South America was rapid.  © 2006 The Linnean Society of London, Biological Journal of the Linnean Society , 2006, 87 , 611–624.  相似文献   

8.
We describe Centrolene bacatum , C. buckleyi , Cochranella posadae , and a new species of Cochranella from Yanayacu Biological Station on the Amazonian slopes of the Ecuadorian Andes. The new species differs from other species in Centrolenidae by a combination of characters, including reduced webbing between Fingers III and IV, and kidneys covered with white peritoneum. We summarize the current generic and infrageneric classification in Centrolenidae and discuss some of its problems. A phylogenetic analysis of morphological and behavioural data shows that the genera Centrolene and Cochranella might not be monophyletic; the genus Hyalinobatrachium and, in particular, the group H. fleischmanni seem to be monophyletic. However, an analysis with many more characters is needed to resolve the relationships of glass frogs.  © 2006 The Linnean Society of London, Zoological Journal of the Linnean Society , 2006, 147 , 489–513.  相似文献   

9.
The genus Hexabathynella (Crustacea, Malacostraca, Bathynellacea) is revised in the sense of the phylogenetic systematics and four new species are described from South Africa ( H. monoaethetasca sp. nov. and H. africana sp. nov. ) and America ( H. schrieveri sp. nov. and H. virginiae sp. nov. ). A comparative analysis of all observable outer structures distributed in 18 known and four new species resulted in a re-evaluation of 18 characters and character states. The phylogenetic analysis using the program PAUP yielded one most-parsimonious tree, which suggests the grouping of ( H. decora (( H. halophila  +  H. aotearoae ) + ( H. pauliani ( H. monoaethetasca  + H. africana )))) + ( H. knoepffleri ( H. nicoleiana ( H. hebrica , H. tenera , H. longiappendiculata , H. breviappendiculata , H. nestica ) +  H. virginiae (( H. minuta ( H. valdecasasi + H. otayana )) + ( H. hessleri + H. muliebris ))) +  H. paranaensis ( H. szidati + H. schrieveri )). The tree is 57 steps long and has a consistency index of 0.6140, a retention index of 0.7982 and a rescaled consistency index of 0.4901. The result does not agree with the previous analyses on the genus. In terms of sampling and coding, the characters used in the previous study are critically assessed.  © 2006 The Linnean Society of London, Zoological Journal of the Linnean Society , 2006, 147 , 71–96.  相似文献   

10.
Chromosome counts are reported of 38 populations representing 24 species of the genus Cousinia from Iran, one of the main centres of speciation of the genus. Sixteen of the counts are new to science. Our results confirm that Cousinia exhibits a complex dysploid series ranging from x  = 13 to x  = 9. One of the basic chromosome numbers, x  = 9, is new for the genus and must be confirmed. Some considerations on the correlation between chromosome numbers and section classification are made.  © 2006 The Linnean Society of London, Botanical Journal of the Linnean Society , 2006, 151 , 411–419.  相似文献   

11.
Micromorphological characters of the fruiting bodies, such as ascus-type and hymenial amyloidity, and secondary chemistry have been widely employed as key characters in Ascomycota classification. However, the evolution of these characters has yet not been studied using molecular phylogenies. We have used a combined Bayesian and maximum likelihood based approach to trace character evolution on a tree inferred from a combined analysis of nuclear and mitochondrial ribosomal DNA sequences. The maximum likelihood aspect overcomes simplifications inherent in maximum parsimony methods, whereas the Markov chain Monte Carlo aspect renders results independent of any particular phylogenetic tree. The results indicate that the evolution of the two chemical characters is quite different, being stable once developed for the medullary lecanoric acid, whereas the cortical chlorinated xanthones appear to have been lost several times. The current ascus-types and the amyloidity of the hymenial gel in Pertusariaceae appear to have been developed within the family. The basal ascus-type of pertusarialean fungi remains unknown.  © 2006 The Linnean Society of London, Biological Journal of the Linnean Society , 2006, 89 , 615–626.  相似文献   

12.
The use of colour characters in phylogenetic reconstruction   总被引:1,自引:0,他引:1  
The use of coloration as a source of characters in phylogenetic reconstruction is investigated using 54 published data sets. Studies were divided into two categories based on a priori postulated roles of the coloration: (1) aposematic and mimetic coloration and (2) nonaposematic, nonmimetic coloration plus dual signals. Colour characters superficially appear to provide similar phylogenetic signal to morphological ones in the case of aposematic and mimetic coloration but significantly less in other situations. However, the data indicated that the apparent signal in the aposematic/mimetic studies tends to be in greater conflict with the morphological signal. It is proposed that this reflects constraints in the evolution of colour characters that are part of aposematic/mimetic patterns and not that they are necessarily good indicators of phylogeny.  © 2006 The Linnean Society of London, Biological Journal of the Linnean Society , 2006, 88 , 193–202.  相似文献   

13.
Previous phylogenetic analyses of Orchidaceae subtribe Orchidinae resulted in the proposal to classify Coeloglossum viride (L.) Hartman within the genus Dactylorhiza in order to maintain its monophyly. In this paper, we report some results that contradict previous studies regarding the monophyly of the traditional Dactylorhiza and its phylogenetic relationship with Coeloglossum. Our results, which combine sequences of the internal and external transcribed spacers of the nuclear ribosomal DNA, support the monophyly of Dactylorhiza , with Coeloglossum being a sister clade. The position of C. viride in the phylogenetic tree, and the considerable morphological differences with respect to Dactylorhiza , incline us to retain both lineages as distinct genera.  © 2006 The Linnean Society of London, Botanical Journal of the Linnean Society , 2006, 152 , 261–269.  相似文献   

14.
The systematic biology of the subgenus Daphnia s . s . remains confused. Prior attempts at resolution used chiefly postabdominal claw morphology, chromosome numbers and rRNA gene sequences as characters for higher-level relations. Still, several taxa, such as Daphnia curvirostris Eylmann, 1878, have unclear affiliations. We addressed the position of D. curvirostris in this genus by estimating phylogenetic trees from a rapidly evolving protein coding gene (ND2), conducting broad geographical comparisons and carrying out detailed morphological comparisons. The Japanese ' curvirostris' was found to be a new divergent lineage in the subgenus Daphnia , and to possess distinctive morphological characteristics from D. curvirostris . We described this new species as Daphnia tanakai sp. nov. , and redescribed D. curvirostris . The polymorphic postabdominal claw morphology and the distinctive chromosome number of D. tanakai sp. nov. provided evidence for rapid evolution of these traits. Our new morphological, chromosomal and genetic assessment of Daphnia weakened the argument for division of the subgenus Daphnia ( Daphnia ) O. F. Müller, 1785 sensu Johnson, 1952, into two further subgenera.  © 2006 The Linnean Society of London, Zoological Journal of the Linnean Society , 2006, 146 , 385–405.  相似文献   

15.
16.
The Loranthaceae is the largest plant family with aerial branch parasites termed mistletoes. Three genera of Loranthaceae are terrestrial root parasites and the remaining 72 genera are aerial parasites. Several characters, including habit, haustorial type, germination pattern, pollen morphology, chromosome number, inflorescence morphology and flower merosity, fusion, symmetry and size, are considered to reflect evolutionary relationships within the family. Convergence is a common evolutionary pattern and can confound interpretations of evolution. We investigated character evolution by mapping character states onto a phylogenetic tree based on the nuclear ITS and chloroplast trnL–trnF regions. Convergences in form were found in several characters, including habit, haustorial type, flower symmetry and merosity. These convergences typically correspond to ecological parameters such as pollination syndrome or stresses associated with the canopy habit. Other characters such as chromosome number and germination pattern illustrate divergent evolution among clades.  © 2006 The Linnean Society of London, Botanical Journal of the Linnean Society , 2006, 150 , 101–113.  相似文献   

17.
Puya , a large genus mostly from South America, has been taxonomically divided into two subgenera: Puyopsis and Puya. The latter includes only eight species distributed mainly in Chile, extending to Argentina, Bolivia, and Peru. The species of subgenus Puya are recognized by the presence of a sterile apex of the inflorescence branches, whereas those of subgenus Puyopsis have fertile flowers all along the branches. The objectives of this article were to determine whether this diagnostic character was synapomorphic for subgenus Puya , and to explore the relationships between its species. Parsimony analyses were performed for 43 taxa and 93 morphological characters, 87 of which were discrete and six continuous. In the analysis that included all characters, a single most parsimonious tree was found that supported subgenus Puya by two synapomorphic character states, including the diagnostic character of a sterile inflorescence branch apex and a blooming pattern in which flowers open gradually from base to apex. The trees were better supported when the continuous characters were included. Further studies are suggested to resolve the infrageneric classification of Puya and the relationships of the species belonging to subgenus Puya .  © 2008 The Linnean Society of London, Botanical Journal of the Linnean Society , 2008, 156 , 93–110.  相似文献   

18.
Species of Eunice are distributed worldwide, inhabiting soft and hard marine bottoms. Some of these species play significant roles in coral reef communities and others are commercially important. Eunice is the largest and most poorly defined genus in Eunicidae. It has traditionally been subdivided in taxonomically informal groups based on the colour and dentition of subacicular hooks, and branchial distribution. The monophyly of Eunice and of its informal subgroups is tested here using cladistic analyses of 24 ingroup species based on morphological data. In the phylogenetic hypothesis resulting from the present analyses Eunice and its subgroups are paraphyletic; the genus may be divided in at least two monophyletic groups, Eunice s.s. and Leodice , but several species do not fall inside these two groups. Most of the traditional characters used in the taxonomy of Eunice are homoplasies; however, characters used for the first time in this study, such as certain jaw characters and characters derived from a close examination of chaetal variation along the body, are promising sources of phylogenetic signal.  © 2007 The Linnean Society of London, Zoological Journal of the Linnean Society , 2007, 150 , 413–434.  相似文献   

19.
To estimate the potential contribution of ethological and ecological parameters to the mechanisms of species formation and species isolation in the Palearctic cicada genus Tibicina , we constructed a molecular phylogenetic hypothesis of extant Tibicina species. Seven mitochondrial genes and a fragment of a nuclear gene were sequenced (3046 bp). Mitochondrial genes included 547 informative sites but the nuclear gene was too conserved to be included in the analysis. The tree was characterized by a basal polytomy indicating that Tibicina species arose rapidly. Such rapid radiation might explain the low divergence in the acoustic communication observed between species. Parameters describing habitat selection and acoustic communication were mapped onto the tree. A shift in habitat selection accompanied by acoustic changes might have contributed to one speciation event. The stochastic distribution of the same acoustic characters on the other branches of the tree implies, however, that the subtle acoustic differences between species could be the result of previous speciation events and independent evolutionary histories, rather than having contributed themselves in the speciation and isolation processes.  © 2007 The Linnean Society of London, Biological Journal of the Linnean Society , 2007, 91 , 611–626.  相似文献   

20.
Paeonia (Paeoniaceae) in the Caucasus   总被引:1,自引:0,他引:1  
The taxonomy of the genus Paeonia in the Caucasus has been controversial, with recognized species varying in number from one to 13. The taxonomic history of Paeonia in this area is reviewed (including an analysis of the characters used by previous authors) based on extensive field observations, population sampling and critical examination of a large number of herbarium specimens. The results show that Paeonia may be divided into three groups. The P. intermedia group is known from only a single population. In the P. tenuifolia group, all the characters used for distinguishing the three previously recognized species were found to be polymorphic. In the P. daurica group, petal colour, shape and size of leaflets, and indumentum of leaflets and carpels were used to distinguish nine species, but these characters were found to be polymorphic or continuous in variation, and thus can only be used for infraspecific classification. Thus, three species are recognized: P. intermedia , P. tenuifolia and P. daurica . The last species is further divided into five subspecies: sspp. coriifolia , wittmanniana , mlokosewitschii , macrophylla and tomentosa stat. nov .  © 2003 The Linnean Society of London, Botanical Journal of the Linnean Society, 2003, 143 , 135–150.  相似文献   

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