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1.
Heracula discivitta Moore is an uncommon moth species currently recorded from India, Nepal and China. Although this species has traditionally been placed in Lymantriinae, its systematic position in Macroheterocera has been enigmatic due to its unique morphological features. Here we used molecular and morphological data to explore the systematic position of H. discivitta. Our molecular phylogenetic analyses indicate that this species is sister to Pseudobiston pinratanai Inoue, a member of a recently established monotypic family Pseudobistonidae. The examinations of morphological features further show that H. discivitta shares synapomorphies with Pseudobistonidae. Based on the analysis results, we propose a new subfamily of Pseudobistonidae (Heraculinae subfam.n. ) to accommodate H. discivitta. The resemblance of the habitus to that of the brahmaeid genus Calliprogonos Mell & Hering is discussed. This published work has been registered on ZooBank, http://zoobank.org/urn:lsid:urn:lsid:zoobank.org:pub:63D17850‐6D51‐4E03‐A5D6‐F9EF6E7AF402 .  相似文献   

2.
We review the morphological and molecular evidence that Mayden & Chen recently used to infer that the developmentally truncated fish genus Paedocypris is not a member of the teleost order Cypriniformes or carp‐like fishes, but is ‘the basal sister group to all Cypriniformes’. This hypothesis contradicts several previous studies that used molecular sequence data or morphological characters. A review of the morphological characters that Mayden & Chen discussed and mapped onto their ‘simplified tree’ shows that these, analysed alone, rather support a close relationship of the cyprinids Sundadanio, Danionella, and Paedocypris. We also present four additional analyses of morphological data, which all contradict Mayden & Chen's result. Despite its highly reductive skeleton, posing a serious problem when analysing its phylogenetic position with skeletal characters, the presence in Paedocypris of the basioccipital masticatory plate is compelling evidence that it is a member of the Cyprinoidei (Cyprinidae plus Psilorhynchidae). Our reanalysis and exploration of their molecular sequence data shows that only a single gene, EGR3, of the six nuclear genes analysed by Mayden & Chen, is responsible for the position of Paedocypris as ‘the basal sister group to all Cypriniformes’. Three independent methods to visualize and analyse phylogenetic signal and conflict of data sets (phylogenetic networks, splits analysis methods or SAMS, and site‐wise likelihood analyses) reveal a high level of character conflict and noise in Mayden & Chen's data set. The ‘basal’ position of Paedocypris seems to be the outcome of the interplay of two long‐branch effects. We apply the same analytical methods to the data set from Rüber et al.'s molecular analysis of the phylogenetic position of Paedocypris and discuss our findings. We conclude that none of the molecular data sets compiled to date can establish the phylogenetic position of Paedocypris with confidence. Morphological data suggest that Paedocypris and Danionella are sister genera, and that their closest relative is Sundadanio, although the position of these three miniatures among cyprinoids is still unclear. © 2014 The Linnean Society of London  相似文献   

3.
We describe a new species, Semispathidium breviarmatum sp. n., from tropical Africa and analyse its phylogenetic position within the subclass Haptoria, using live observation, various silver impregnation methods, SEM and the 18S rRNA gene. Semispathidium breviarmatum differs from its congeners by the much higher number of ciliary rows and by the shape and size of the extrusomes, that is, extrusive organelles that kill the prey. The phylogenetic position of Semispathidium is controversial due to its ‘hybrid’ morphology. Specifically, the cylindroidal body has a more or less discoidal oral bulge indicating an enchelyodonid origin, while the anteriorly curved somatic kineties suggest a spathidiid ancestor. In order to reconstruct the evolutionary history of Semispathidium and to unravel its affinity to other haptorians, we used synergistic effects of combining morphological and molecular data coming from 34 haptorian taxa. These analyses show that Semispathidium belongs to the order Spathidiida representing a basal lineage that is far from ordinary Spathidium species, but very likely related to Protospathidium and Enchelys. Any closer phylogenetic relationship between Semispathidium and Enchelyodon spp. is not recognized in morphological and molecular phylogenies and is consistently excluded by statistical tree topology tests.  相似文献   

4.
Amana banghaasi Hering, a poorly known species from central China (described in the “Epiplemidae”, now Epipleminae [Uraniidae]), is transferred to a new genus, Deuveia, which belongs to the Epicopeiidae (Drepanoidea). This taxon turns out to be the sister-group of a clade consisting of all other members of the family. Another new epicopeiid genus, Burmeia, is proposed for B. leesi n. sp., a species described from northern Burma. Quite clearly, there is a sister-group relationship between Burmeia and Psychostrophia, but these genera differ markedly in certain characters, for example in the course of vein M2: in both pairs of wings, M2 arises distinctly closer to M3 than to M1 in Burmeia, unlike the condition found in all other Epicopeiidae. A key is provided for the identification of the species in these two genera. A manually derived cladogram may correctly sum up the phylogeny of the Epicopeiidae, a family now composed of nine genera. It matches exactly one of the two most parsimonious trees found with computer programs such as Hennig86 or PAUP (the second tree of minimal length being similar, except for the affinities of the monotypic genus Amana). For the software-based analyses, all the 34 (imaginal) characters taken into account were polarized and given equal weight. The “robustness” of each branch of the preferred cladogram was assessed by calculating the corresponding Bremer’s support index, but also with non-quantifiable criteria. Six genera may form a clade, within which the following sister-group relationships can be considered well established: Chatamla/Parabraxas, Nossa/Epicopeia, and Schistomitra/Nossa + Epicopeia (whereas Chatamla + Parabraxas is only tentatively regarded as sister to Amana). Owing to the basal position of Deuveia within the Epicopeiidae, the morphology of this genus is of great significance to identify the autapomorphies of the Drepanoidea and those of the Epicopeiidae (respectively 5 and 12 in number at this stage of the investigations). With regard to the Drepanidae, an apomorphy of the male genitalia can be added to the definition of the family, whose basalmost lineage probably is the subfamily Cyclidiinae. The composition of the Thyatirinae is briefly discussed.  相似文献   

5.
The phylogenetic position of the most speciose meiofaunal polychaete family, Nerillidae, has remained contentious. Recent hypotheses have generally focused on the fact that Nerillidae shares with Aciculata (a major polychaete subgroup) features such as compound chaetae, ventral buccal organ and short ventrolateral palps. Here we present the first phylogenetic analysis of Aciculata, together with Nerillidae, combining morphological and molecular data. We also include Aberrantidae, previously referred to or placed near to spiomorph polychaetes, but recently referred to Aciculata, possibly close to Nerillidae. The data sets of 24 terminals contain 53 morphological characters and nearly complete sequences of 18S rRNA. The sequences were analysed simultaneously with the morphological data by direct optimization in the program POY with a variety of parameter settings (costs of gaps: transversions: transitions). The various settings resulted in markedly different phylogenetic hypotheses, but on the basis of congruence (ILD) the results of two parameter settings were chosen. In all analyses, the three included nerillid species constituted a monophyletic group. Only two analyses provided fully resolved cladograms. The morphological analysis gave poor resolution and the position of the nerillids was equivocal. The two molecular‐based cladograms (minimizing ILD) were also poorly resolved, but one provided a position for nerillids next to Eunice pennata and Nothria conchilega, from the subgroup Eunicida within Aciculata. The two cladograms of the combined analyses (minimizing ILD) were fully resolved and placed nerillids in a terminal position next to Aberranta sp., within a clade of eunicidan species. The study showed that the analytical conditions for the homology assignment of 18S rRNA strongly influenced the phylogenetic results. The various previous proposals on the phylogenetic position of the Nerillidae are reviewed, some of which are in accordance with the results of the present study.  相似文献   

6.
We studied the morphology and molecular phylogeny of Myoschiston duplicatum, a peritrich ciliate that has been recorded as an epibiont of crustaceans, but which we also identified on marine algae from Korea. The important morphological characteristics revealed by silver staining of Myoschiston species have not been described because they are rarely collected. Using morphological methods, we redescribed the type species of the genus, Myoschiston duplicatum, and provided an improved diagnosis of Myoschiston. In addition, the coding regions for nuclear small subunit (SSU) rRNA and internal transcribed spacer 1‐5.8S‐internal transcribed spacer 2 sequences were sequenced. Phylogenetic analyses that included available SSU rDNA sequences of peritrichs from GenBank strongly supported a position of M. duplicatum within the family Zoothamniidae. In addition, phylogenetic analyses were performed with single datasets (ITS1‐5.8S‐ITS2) and combined datasets (SSU rDNA + ITS1‐5.8S‐ITS2) to explore further the phylogenetic relationship in the family Zoothamniidae between the three morphologically similar genera—Zoothamnium, Myoschiston, and Zoothamnopsis.  相似文献   

7.
The diversity of hypotrichous ciliates has encouraged numerous researchers to use a combination of morphological, morphogenetic, and phylogenetic data to provide a better understanding of the evolutionary relationships within this complex group. In this study, we investigate the morphology and morphogenesis of Pseudourostyla subtropica sp. nov., isolated from mangrove wetland. The new species can be distinguished from its congeners by the huge body size, many more adoral membranelles and marginal cirral rows, and numerous macronuclear nodules. In addition, we provide a morphological characterization of a population of Pseudourostyla nova Wiackowski 1988 from an estuarine habitat. The main events during binary fission of P. subtropica sp. nov. and the Chinese population of P. nova are also revealed to be conservative. The morphological, ontogenetic, and phylogenetic analyses based on the SSU rDNA sequences corroborate the monophyly of Pseudourostyla Borror, 1972, which corresponds well with previous research. The phylogenetic analyses also show that Pseudourostyla and Hemicycliostyla Stokes, 1886, both of which are assigned to the family Pseudourostylidae based on morphological and morphogenetic data, in fact fall into separated clades. The approximately unbiased tests, however, do not reject the possibility that the family Pseudourostylidae is a monophyletic lineage.  相似文献   

8.
The speciation history of Anaspides tasmaniae (Crustacea: Malacostraca) and its close relatives (family Anaspididae) was studied by phylogenetic and molecular clock analyses of mitochondrial DNA sequences. The phylogenetic analyses revealed that the Anaspides morphotype conceals at least three cryptic species belonging to different parts of its range. The occurrence of multiple cryptic phylogenetic species within one morphological type shows that substantial genetic evolution has occurred independently of morphological evolution. Molecular clock dating of the speciation events that generated both the cryptic and the morphological species of Anaspididae indicated continuous speciation within this group since the Palaeocene ~55 million years ago. This relatively constant rate of recent morphological and cryptic speciation within the Anaspididae suggests that the speciation rate in this group does not correlate with its low extinction rate or morphological conservatism.  相似文献   

9.
Taxa missing large amounts of data pose challenges that may hinder the recovery of a well‐resolved, accurate phylogeny and leave questions surrounding their phylogenetic position. Systematists commonly have to contend with one or two species in a group for which there is little or no material available suitable for recovering molecular data. It is unclear whether these taxa can be better placed using analyses based on morphological data only, or should be included in broader analyses based on both morphological and molecular data. The extinct madtom catfish Noturus trautmani is known from few specimens for which molecular data are unavailable. We included this taxon in parsimony and Bayesian analyses of relationships of madtom catfishes based on a combination of morphological and molecular data. Results indicate that using a combination of morphological and molecular data does a better job at providing a phylogenetic placement for N. trautmani than morphology alone, even though it is missing all of its molecular characters. We provide a novel hypothesis of relationships among Noturus species and recommendations for classification within the group. © 2009 The Linnean Society of London, Zoological Journal of the Linnean Society, 2009, 155 , 60–75.  相似文献   

10.
Current taxonomy of the Bryopsidales recognizes eight families; most of which are further categorized into two suborders, the Bryopsidineae and Halimedineae. This concept was supported by early molecular phylogenetic analyses based on rRNA sequence data, but subsequent cladistic analyses of morphological characters inferred monophyly in only the Halimedineae. These conflicting results prompted the current analysis of 32 taxa from this diverse group of green algae based on plastid‐encoded RUBISCO large subunit (rbcL) gene sequences. Results of these analyses suggested that the Halimedineae and Bryopsidineae are distinct monophyletic lineages. The families Bryopsidaceae, Caulerpaceae, Codiaceae, Derbesiaceae, and Halimediaceae were inferred as monophyletic, however the Udoteaceae was inferred as non‐monophyletic. The phylogenetic position of two taxa with uncertain subordinal affinity, Dichotomosiphon tuberosus Lawson and Pseudocodium floridanum Dawes & Mathieson, were also inferred. Pseudocodium was consistently placed within the halimedinean clade suggesting its inclusion into this suborder, however familial affinity was not resolved. D. tuberosus was the inferred sister taxon of the Halimedineae based on analyses of rbcL sequence data and thus a possible member of this suborder.  相似文献   

11.
The existence of the platyhelminth clade Adiaphanida—an assemblage comprising the well‐studied order Tricladida as well as two lesser known taxa, Prolecithophora and the obligate parasitic Fecampiida—is among the more surprising results of flatworm molecular systematics. Each of these three clades is itself largely well‐defined from a morphological point of view, although Adiaphanida at large, despite its strong support in molecular phylogenetic analyses, lacks known morphological synapomorphies. However, one taxon, the genus Genostoma, a parasite of the leptostracan crustacean Nebalia, rests uneasily within its current classification within the fecampiid family Genostomatidae; ultrastructural investigations on this taxon have uncovered a spermatogenesis reminiscent of Kalyptorhynchia, and a dorsal syncytium resembling the neodermatan tegument. Here, we provide molecular sequence data (nearly complete 18S and 28S rRNA) from a representative of Genostoma, with which we test hypotheses on the phylogenetic position of this taxon within Platyhelminthes, expanding upon a recently published phylum‐wide analysis, and applying novel alignment algorithms and substitution models. These analyses unequivocally position Genostoma as the sister group of Prolecithophora. However, even in taxon‐rich analyses, support for the position of the root of Adiaphanida is lacking, highlighting the need for new data types to study the phylogeny of this clade. Interestingly, our analyses also do not recover the monophyly of several taxa previously proposed, notably Continenticola within Tricladida and Protomonotresidae within Prolecithophora. In light of this phylogeny and the distinctive morphology (especially, spermatogenesis) of Genostoma, we advocate for a redefinition of the family Genostomatidae, outside of both Fecampiida and Prolecithophora, to encompass the members of this unique genus of parasites. Within Fecampiida, the family Piscinquilinidae fam. nov. is erected to accommodate the vertebrate‐parasitic Piscinquilinus, formerly Genostomatidae.  相似文献   

12.
Bracken, H. D., De Grave, S., Toon, A., Felder, D. L. & Crandall, K. A. (2009). Phylogenetic position, systematic status, and divergence time of the Procarididea (Crustacea: Decapoda). —Zoologica Scripta, 39, 198–212. Ever since discovery of the anchialine shrimp, Procaris ascensionis Chace & Manning 1972 , there has been debate as to its systematic position in relationship to other shrimp‐like decapods. Several morphological characters have suggested a close affinity among Procarididae, Dendrobranchiata and Stenopodidea, whereas other physical features unite Procarididae with Caridea. Few molecular studies have examined the phylogenetic position of procaridid shrimp due to limited available material for genetic analyses. Those studies show procaridids as sister to carideans but lack sufficient taxon and locus sampling to validate the relationship. Here, we present a molecular phylogeny of selected individuals across decapod infraorders and superfamilies to clarify the phylogenetic position of procaridid shrimp. One mitochondrial (16S) and three nuclear genes (18S, 28S, H3) have been chosen to elucidate relationships. We used Bayesian molecular dating methods implemented in multidivtime to estimate and compare the divergence times among procaridids and other lineages. Findings secure the placement of the procaridids as a sister clade to carideans. Results provide evidence for the recognition of procaridids as a separate infraorder (Procarididea Felgenhauer & Abele 1983 ) within the Decapoda on the basis of molecular and morphological data.  相似文献   

13.
Echinocereus is a morphologically diverse genus that includes 64 species grouped into eight taxonomic sections based on morphological traits. In previous molecular phylogenetic analyses, the relationships amongst Echinocereus species were not entirely revealed and useful characters to recognize clades were not provided. The inclusion of several sources of evidence in a phylogenetic analysis is likely to produce more supported hypotheses. Therefore, we performed a combined phylogenetic analysis with a set of 44 morphological characters and six chloroplast DNA sequences. Topologies from parsimony and Bayesian analyses were mostly congruent. However, the relationships of E. poselgeri were not consistent between analyses. A second Bayesian analysis using a long-branch extraction test resulted in a topology with the morphological position of E. poselgeri congruent with that in parsimony analysis. Parsimony and Bayesian analyses corroborated the monophyly of Echinocereus, which included eight monophyletic groups. The combined phylogeny integrated into different clades those taxa that were not determined in previous analyses and changed the relationships of some recognized clades. The clades did not recover the recent infrageneric classification. In the present study, a new sectional classification for Echinocereus is proposed based on the eight recovered clades, which is supported by a combination of morphological and molecular characters. An identification key for sections in the genus is included.  相似文献   

14.
15.
Gliridae is a small family of rodents including three subfamilies: the Eurasian Glirinae (with three genera) and Leithiinae (with four genera) and the African Graphiurinae (with a single genus). Phylogenetic relationships among these eight genera are not fully resolved based on morphological characters. Moreover, the genus Graphiurus is characterized by numerous peculiar features (morphological characters and geographical distribution), raising the question of its relationships to the family Gliridae. The phylogenetic position of Graphiurus and the intra-Gliridae relationships are here addressed by a molecular analysis of 12S RNA and cytochrome b mitochondrial gene sequences for six glirid genera. Phylogenetic analyses are performed with three construction methods (neighbor-joining, maximum parsimony and maximum likelihood) and tests of alternative topologies with respect to the most likely. Our analyses reveal that Graphiurus is clearly a member of the Gliridae, refuting the hypothesis that the family could be paraphyletic. Among Gliridae, phylogenetic relationships are poorly resolved: the Leithiinae could be monophyletic, there is no support for the subfamily Glirinae, and the closest relative of Graphiurus is not identified. The inclusion of Graphiurus among Gliridae allows us to postulate that its hystricomorphous condition has been achieved convergently with other hystricomorphous rodents.  相似文献   

16.
This paper studies the family‐level phylogenetic placement of the conflicting Tasmanian spider genus Acrobleps using both morphological and behavioral data. We also provide a formal taxonomic revision of Acrobleps, including information on its web architecture and natural history, as well as detailed morphological information for A. hygrophilus, its only species. Acrobleps hygrophilus lacks the typical mysmenid features. Furthermore A. hygrophilus does have all typical and diagnostic characteristics of Anapidae, except for the labral spur. We also discuss two noteworthy morphological features of Acrobleps: the pore bearing depressions of the carapace and the granulated cuticle of the spinnerets. Variation in the latter feature might provide a useful phylogenetic character. Based on the results of cladistic analyses we propose the transfer of Acrobleps from the Mysmenidae to its original placement within the Anapidae. We also propose a new lineage, informally labeled as the “clawless female clade”, which includes synaphrids, cyatholipids and “symphytognathoids.” The secondary absence of the female palpal claw provides support for the “clawless female clade.” We discuss the evolution of the orb web within anapids and other symphytognathoids based on the results of our cladistic analyses. The identical bi‐dimensional webs of the anapid Elanapis and of symphytognathids have evolved independently. Finally, we comment on the implications of one of our analyses regarding araneoid web evolution. We conclude that the taxon sample included in the previous orbicularian data matrix (modified and used in this study) is adequate to test the phylogenetic placement of Acrobleps in Anapidae but insufficient to significantly assess web evolution within Araneoidea. © The Willi Hennig Society 2007.  相似文献   

17.
18.
《Journal of bryology》2013,35(4):251-256
Abstract

The taxonomic status and phylogenetic position of the monotypic liverwort genus Physotheca J.J.Engel & Gradst., including P. autoica J.J.Engel & Gradst. endemic to Ecuador, are inferred from phylogenetic analyses of two cpDNA loci. The results indicate that the genus is nested within Leptoscyphus and the new combination, L. autoicus (J.J.Engel & Gradst.) Vanderp. & Gradst., is made. This indicates, along with an increasing body of evidence, that extreme morphological transformations can obscure the phylogenetic signal present in morphological data.  相似文献   

19.
The canal-bearing diatom genus Nagumoea, described based on only morphological evidence, was tentatively assigned to the order Bacillariales, although its phylogenetic position remained unclear. Because three isolates of Nagumoea (SK002, SK024 and SK053) were successfully established from Japanese coasts, we performed their morphological observations and molecular phylogenetic analyses to discuss the phylogeny and taxonomic position of this genus. Strains SK002 and SK024 were identified as Nagumoea africana, whereas SK053 conformed with Nagumoea serrata. There was high interspecific divergence between N. africana and N. serrata in the rbcL sequences (8.03–8.17%), indicating their distinctness. Furthermore, intraspecific variations were detected within N. africana (2.35%) in the rbcL, implying its cryptic diversity. The maximum likelihood and Bayesian phylogenetic trees inferred from the plastid rbcL, psbC and nuclear 18S rDNA genes recovered Nagumoea as monophyletic with strong statistical support and embedded within an unresolved, poorly supported lineage containing Achnanthes, Craspedostauros, Staurotropis and Undatella in the canal-bearing order Bacillariales (= the family Bacillariaceae). Although the constrained tree based on the monophyly of Nagumoea and the other canal-bearing clade (Surirellales and Rhopalodiales) was statistically rejected by the topology tests, the phylogenetic position of Nagumoea with other Bacillarialean members remains equivocal. The possession of two plastids positioned fore and aft, observed in the present study, and lack of keel, typical of the Bacillariales, indicate the possibility of Nagumoea being part of the ingroup of the Bacillariales or its closely related outgroup.  相似文献   

20.

Background  

Paedocypris, a highly developmentally truncated fish from peat swamp forests in Southeast Asia, comprises the world's smallest vertebrate. Although clearly a cyprinid fish, a hypothesis about its phylogenetic position among the subfamilies of this largest teleost family, with over 2400 species, does not exist. Here we present a phylogenetic analyses of 227 cypriniform taxa, including 213 cyprinids, based upon complete mitochondrial DNA cytochrome b nucleotide sequences in order to determine the phylogenetic position of Paedocypris and to study the evolution of miniaturization among cyprinids.  相似文献   

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