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1.
Pentatomoidea (stink bugs and their relatives) is the third largest superfamily in Heteroptera, or the true bugs. The phylogenetic relationships among the families within Pentatomoidea remain controversial. The family Lestoniidae is morphologically highly specialized, currently including only two species endemic to Australia. Previous researchers have suggested a close relationship of Lestoniidae to either Plataspidae or Acanthosomatidae, based on morphological characters. In this study, phylogenetic tree reconstruction revealed that Lestoniidae and Acanthosomatidae form a monophyletic clade. In addition, in comparisons of the secondary structures of 18S and 28S rRNAs representing 15 families of Pentatomoidea, four length‐variable regions in 18S and 28S rRNAs that can serve as autapomorphies for the clade Lestoniidae + Acanthosomatidae were recognized. Among them, E in 18S rRNA and D3‐1 and D5‐1 in 28S rRNA are unique in length in Lestoniidae and Acanthosomatidae. Based on the new molecular evidence and morphological evidence published by previous authors, Lestoniidae is suggested to be a highly specialized group derived from a common ancestor with Acanthosomatidae.  相似文献   

2.
A new Progonocimicidae species, Cicadocoris anisomeridis sp.n. , with asymmetrical tegmina is described from the Middle Jurassic Jiulongshan Formation in northeastern China. This is the fifth report of Coleorrhyncha from China. A cladistic analysis based on a combination of fossil and extant taxa clarifies the phylogenetic status of the new fossils and allows the reconstruction of inter‐subfamily relationships within the suborder Coleorrhyncha. Coleorrhyncha is monophyletic and divided into two main clades. Progonocimicidae comprises a monophyletic lineage, to which the new fossils belong. The broadly conceived Progonocimicinae and Cicadocorinae, as recognized by earlier authors, are not supported. The monophyly of the family Karabasiidae is also not supported, and its two constituent subfamilies Hoploridiinae and Karabasiinae are raised to family rank. Hoploridiidae is found to be sister group to all extant moss bugs, and Karabasiidae is found to be the monophyletic sister group to Hoploridiidae + all extant moss bugs. This published work has been registered in ZooBank, http://zoobank.org/urn:lsid:zoobank.org:pub:30BC0498‐3B8A‐4650‐BC9D‐02A0C8D870B2 .  相似文献   

3.
4.
The phylogenetic relationships of branchiopod crustaceans have been in the focus of a number of recent morphological and molecular systematic studies. Although agreeing in some respects, major differences remain. We analyzed molecular sequences and morphological characters for 43 branchiopods and two outgroups. The branchiopod terminals comprise all eight “orders”. The molecular data include six loci: two nuclear ribosomal genes (18S rRNA, 28S rRNA), two mitochondrial ribosomal genes (12S rRNA, 16S rRNA), one nuclear protein coding gene (elongation factor 1α), and one mitochondrial protein coding gene (cytochrome c oxidase subunit I). A total of 65 morphological characters were analyzed dealing with different aspects of branchiopod morphology, including internal anatomy and larval characters. The morphological analysis resulted in a monophyletic Phyllopoda, with Notostraca as the sister group to the remaining taxa supporting the Diplostraca concept (“Conchostraca” + Cladocera). “Conchostraca” is not supported but Cyclestheria hislopi is the sister group to Cladocera (constituting together Cladoceromorpha) and Spinicaudata is closer to Cladoceromorpha than to Laevicaudata. Cladocera is supported as monophyletic. The combined analysis under equal weighting gave results in some respects similar to the morphological analysis. Within Phyllopoda, Cladocera, Cladoceromorpha and Spinicaudata + Cladoceromorpha are monophyletic. The combined analysis is different from the morphological analysis with respect to the position of Notostraca and Laevicaudata. Here, Laevicaudata is the sister group to the remaining Phyllopoda and Notostraca is sister group to Spinicaudata and Cladoceromorpha. A sensitivity analysis using 20 different parameter sets (different insertion–deletion [indel]/substitution and transversion/transition ratios) show the monophyly of Anostraca, Notostraca, Laevicaudata, Spinicaudata, Cladoceromorpha, Cladocera, and within Cladocera, of Onychopoda and Gymnomera under all or almost all (i.e., 19 of 20) parameter sets. Analyses with an indel‐to‐transversion ratio up to 2 result in monophyletic Phyllopoda, with Laevicaudata as sister group to the remaining Phyllopoda and with Spinicaudata and Cladoceromorpha as sister groups. Almost all analyses (including those with higher indel weights) result in the same topology when only ingroup taxa are considered. © The Willi Hennig Society 2007.  相似文献   

5.
Apple snails (Ampullariidae) are a diverse family of pantropical freshwater snails and an important evolutionary link to the common ancestor of the largest group of living gastropods, the Caenogastropoda. A clear understanding of relationships within the Ampullariidae, and identification of their sister taxon, is therefore important for interpreting gastropod evolution in general. Unfortunately, the overall pattern has been clouded by confused systematics within the family and equivocal results regarding the family's sister group relationships. To clarify the relationships among ampullariid genera and to evaluate the influence of including or excluding possible sister taxa, we used data from five genes, three nuclear and two mitochondrial, from representatives of all nine extant ampullariid genera, and species of Viviparidae, Cyclophoridae, and Campanilidae, to reconstruct the phylogeny of apple snails, and determine their affinities to these possible sister groups. The results obtained indicate that the Old and New World ampullariids are reciprocally monophyletic with probable Gondwanan origins. All four Old World genera, Afropomus, Saulea, Pila, and Lanistes, were recovered as monophyletic, but only Asolene, Felipponea, and Pomella were monophyletic among the five New World genera, with Marisa paraphyletic and Pomacea polyphyletic. Estimates of divergence times among New World taxa suggest that diversification began shortly after the separation of Africa and South America and has probably been influenced by hydrogeological events over the last 90 Myr. The sister group of the Ampullariidae remains unresolved, but analyses omitting certain outgroup taxa suggest the need for dense taxonomic sampling to increase phylogenetic accuracy within the ingroup. The results obtained also indicate that defining the sister group of the Ampullariidae and clarifying relationships among basal caenogastropods will require increased taxon sampling within these four families, and synthesis of both morphological and molecular data. © 2009 The Linnean Society of London, Biological Journal of the Linnean Society, 2009, 98 , 61–76.  相似文献   

6.
Abstract Dictyoptera, comprising Blattaria, Isoptera, and Mantodea, are diverse in appearance and life history, and are strongly supported as monophyletic. We downloaded COII, 16S, 18S, and 28S sequences of 39 dictyopteran species from GenBank. Ribosomal RNA sequences were aligned manually with reference to secondary structure. We included morphological data (maximum of 175 characters) for 12 of these taxa and for an additional 15 dictyopteran taxa (for which we had only morphological data). We had two datasets, a 59‐taxon dataset with five outgroup taxa, from Phasmatodea (2 taxa), Mantophasmatodea (1 taxon), Embioptera (1 taxon), and Grylloblattodea (1 taxon), and a 62‐taxon dataset with three additional outgroup taxa from Plecoptera (1 taxon), Dermaptera (1 taxon) and Orthoptera (1 taxon). We analysed the combined molecular?morphological dataset using the doublet and MK models in Mr Bayes , and using a parsimony heuristic search in paup . Within the monophyletic Mantodea, Mantoida is recovered as sister to the rest of Mantodea, followed by Chaeteessa; the monophyly of most of the more derived families as defined currently is not supported. We recovered novel phylogenetic hypotheses about the taxa within Blattodea (following Hennig, containing Isoptera). Unique to our study, one Bayesian analysis places Polyphagoidea as sister to all other Dictyoptera; other analyses and/or the addition of certain orthopteran sequences, however, place Polyphagoidea more deeply within Dictyoptera. Isoptera falls within the cockroaches, sister to the genus Cryptocercus. Separate parsimony analyses of independent gene fragments suggest that gene selection is an important factor in tree reconstruction. When we varied the ingroup taxa and/or outgroup taxa, the internal dictyopteran relationships differed in the position of several taxa of interest, including Cryptocercus, Polyphaga, Periplaneta and Supella. This provides further evidence that the choice of both outgroup and ingroup taxa greatly affects tree topology.  相似文献   

7.
The marine order Arthrotardigrada (class Heterotardigrada, phylum Tardigrada) is known for its conspicuously high morphological diversity and has been traditionally recognized as the most ancestral group within the phylum. Despite its potential importance in understanding the evolution of the phylum, the phylogenetic relationships of Arthrotardigrada have not been clarified. This study conducted molecular phylogenetic analyses of the order encompassing all families except Neoarctidae using nuclear 18S and 28S rRNA fragments. Data from two rare families, Coronarctidae and Renaudarctidae, were included for the first time. The analyses confirmed the monophyly of Heterotardigrada and inferred Coronarctidae as the sister group to all other heterotardigrade taxa. Furthermore, the results support a monophyletic Renaudarctidae + Stygarctidae clade, which has been previously suggested on morphology. Our data indicated that two subfamilies currently placed in Halechiniscidae are only distantly related to this family. We propose that these taxa are each elevated to family level (Styraconyxidae (new rank) and Tanarctidae (new rank)). The morphology of tardigrades is discussed in the context of the inferred phylogeny.  相似文献   

8.
The first comprehensive analysis of higher‐level phylogeny of the order Hymenoptera is presented. The analysis includes representatives of all extant superfamilies, scored for 392 morphological characters, and sequence data for four loci (18S, 28S, COI and EF‐1α). Including three outgroup taxa, 111 terminals were analyzed. Relationships within symphytans (sawflies) and Apocrita are mostly resolved. Well supported relationships include: Xyeloidea is monophyletic, Cephoidea is the sister group of Siricoidea + [Xiphydrioidea + (Orussoidea + Apocrita)]; Anaxyelidae is included in the Siricoidea, and together they are the sister group of Xiphydrioidea + (Orussoidea + Apocrita); Orussoidea is the sister group of Apocrita, Apocrita is monophyletic; Evanioidea is monophyletic; Aculeata is the sister group of Evanioidea; Proctotrupomorpha is monophyletic; Ichneumonoidea is the sister group of Proctotrupomorpha; Platygastroidea is sister group to Cynipoidea, and together they are sister group to the remaining Proctotrupomorpha; Proctotrupoidea s. str. is monophyletic; Mymarommatoidea is the sister group of Chalcidoidea; Mymarommatoidea + Chalcidoidea + Diaprioidea is monophyletic. Weakly supported relationships include: Stephanoidea is the sister group of the remaining Apocrita; Diaprioidea is monophyletic; Ceraphronoidea is the sister group of Megalyroidea, which together form the sister group of [Trigonaloidea (Aculeata + Evanioidea)]. Aside from paraphyly of Vespoidea within Aculeata, all currently recognized superfamilies are supported as monophyletic. The diapriid subfamily Ismarinae is raised to family status, Ismaridae stat. nov. © The Will Henning Society 2011.  相似文献   

9.
Previous attempts to resolve plesiosaurian phylogeny are reviewed and a new phylogenetic data set of 66 taxa (67% of ingroup taxa examined directly) and 178 characters (eight new) is presented. We recover two key novel results: a monophyletic Plesiosauridae comprising Plesiosaurus dolichodeirus, Hydrorion brachypterygius, Microcleidus homalospondylus, Occitanosaurus tournemirensis and Seeleyosaurus guilelmiimperatoris; and five plesiosaurian taxa recovered outside the split between Plesiosauroidea and Pliosauroidea. These taxa are Attenborosaurus conybeari, ‘Plesiosaurusmacrocephalus and a clade comprising Archaeonectrus rostratus, Macroplata tenuiceps and BMNH 49202. Based on this result, a new name, Neoplesiosauria, is erected for the clade comprising Plesiosauroidea and Pliosauroidea. Taxon subsamples of the new dataset are used to simulate previous investigations of global plesiosaurian relationships. Based on these simulations, most major differences between previous global phylogenetic hypotheses can be attributed to differences in taxon sampling. These include the position of Leptocleididae and Polycotylidae and the monophyly or paraphyly of Rhomaleosauridae. On this basis we favour the results recovered by our, larger analysis. Leptocleididae and Polycotylidae are sister taxa, forming a monophyletic clade within Plesiosauroidea, indicating that the large‐headed, short‐necked ‘pliosauromorph’ body plan evolved twice within Plesiosauria. Rhomaleosauridae forms the monophyletic sister taxon of Pliosauridae within Pliosauroidea. Problems are identified with previous phylogenetic definitions of plesiosaurian clades and new, stem‐based definitions are presented that should maintain their integrity over a range of phylogenetic hypotheses. New, rank‐free clade names Cryptoclidia and Leptocleidia are erected to replace the superfamilies Cryptoclidoidea and Leptocleidoidea. These were problematic as they were nested within the superfamily Plesiosauroidea. The incongruence length difference test indicates no significant difference in levels of homoplasy between cranial and postcranial characters.  相似文献   

10.
We provide the first highly sampled phylogeny estimate for the dipteran family Chironomidae using molecular data from fragments of two ribosomal genes (18S and 28S), one nuclear protein‐coding gene (CAD), and one mitochondrial protein‐coding gene (COI), analysed using mixed‐model Bayesian and maximum likelihood inference methods. The most recently described subfamilies Chilenomyiinae and Usambaromyiinae proved elusive, and are unsampled. We confirm monophyly of all sampled subfamilies except Prodiamesinae, which contains Propsilocerus Kieffer, previously in Orthocladiinae. The semifamily Chironomoinae is confirmed only if Telmatogetoninae is included, which is closer to Brundin's original suggestion. Buchonomyiinae is excluded from Chironomoinae: it is a sister group to all remaining Chironomidae, conforming more to Murray and Ashe's argumentation. Semifamily Tanypodoinae is a grade and unsupported as monophyletic: the austral Aphroteniinae alone is sister to all Chironomidae (less Buchonomyiinae). Podonominae is weakly supported as the next sister group, in contrast to some estimates that place this subfamily as sister group to Tanypodinae alone. In Diamesinae, the southern African Harrisonini is confirmed as a member, but embedded within austral tribe Heptagiini, which is confirmed as sister to the undersampled Diamesini. Tribe Pentaneurini and ‘non‐Pentaneurini’ taxa are reciprocally monophyletic in Tanypodinae. Recent molecular findings concerning Podonominae are substantiated, with a monophyletic tribe Podonomini, Boreochlini forming a grade and Lasiodiamesa Kieffer placed as sister to all other Podonominae, but with uncertainty. In Orthocladiinae, a postulated two‐tribe system of Orthocladiini and Metriocnemini can be supported after exclusion of a Corynoneura group and a Brillia group, which is revealed as sister to Stictocladius Edwards. The marine Clunio Haliday and Thalassosmittia Strenzke & Remmert (given high rank in the past) are clearly embedded deep in Orthocladiinae. The finding of Shangomyia Sæther & Wang + Xyiaomyia Sæther & Wang as sister group to all other Chironominae justifies high rank, as their authors suggested. Pseudochironomini (untested by sampling shortfall) is sister to a monophyletic Tanytarsini (with a weakly supported inclusion of the enigmatic Nandeva Wiedenbrug, Reiss & Fittkau). The tribe Chironomini can be supported only by excluding Shangomyia + Xyiaomyia, and a postulated monophyletic clade comprising several taxa such as Microtendipes Kieffer, with six‐segmented larval antennae and alternate Lauterborn organs, that is sister group to Pseudochironomini + Tanytarsini. The tempo of diversification of the family, deduced by divergence time analysis (beast ), shows Permian origination with subfamily stem‐group origination from the mid–late Triassic to the early Cretaceous. Crown‐group origination ranged from Podonominae on a short stem originating in the mid Jurassic to long‐stemmed Aphroteninae from the late Cretaceous. Node dates allow inference of some vicariance via Gondwanan fragmentation, including certain nodes involving southern Africa.  相似文献   

11.
Annelids and arthropods have long been considered each other's closest relatives, as evidenced by similarities in their segmented body plans. An alternative view, more recently advocated by investigators who have examined partial 18S ribosomal RNA data, proposes that annelids, molluscs, and certain other minor phyla with trochophore larva stages share a more recent common ancestor with one another than any do with arthropods. The two hypotheses are mutually exclusive in explaining spiralian relationships. Cladistic analysis of morphological data does not reveal phylogentic relationships among major spiralian taxa but does suggest monophyly for both the annelids and molluscs. Distance and maximum-likelihood analyses of 18S rRNA gene sequences from major spiralian taxa suggest a sister relationship between annelids and molluscs and provide a clear resolution within the major groups of the spiralians. The parsimonious tree based on molecular data, however, indicates a sister relationship of the Annelida and Bivalvia, and an earlier divergence of the Gastropoda than the Annelida–Bivalvia clade. To test further hypotheses on the phylogenetic relationships among annelids, molluscs, and arthropods, and the ingroup relationships within the major spiralian taxa, we combine the molecular and morphological data sets and subject the combined data matrix to parsimony analysis. The resulting tree suggests that the molluscs and annelids form a monophyletic lineage and unites the molluscan taxa to a monophyletic group. Therefore, the result supports the Eutrochozoa hypothesis and the monophyly of molluscs, and indicates early acquisition of segmented body plans in arthropods. Received: 25 September 1995 / Accepted: 15 March 1996  相似文献   

12.
In the present study, relationships among three genera Acontias, Acontophiops, and Typhlosaurus, that comprise the South African limbless lizard subfamily Acontinae, were assessed with partial sequences of the 16S rRNA mitochondrial DNA gene. In addition, relationships within Acontias were further investigated using sequence data from the cytochrome oxidase I gene (COI). Maximum likelihood and maximum parsimony analyses of the 16S rRNA mtDNA data revealed that within this subfamily, Typhlosaurus is basal while Acontophiops and Acontias are sister taxa. Based on the 16S rRNA mtDNA data, the relationships within Acontias placed A. meleagris orientalis as the sister taxon of A. percivali tasmani, with A. m. orientalis lineacauda morph and A. m. meleagrus being the sister taxa to this group. The small-bodied skinks A. lineatus lineatus and A. l. tristis formed a monophyletic group, with the medium-bodied species A. gracilicauda gracilicauda being their sister taxon. Analyses of the COI gene for Acontias place A. m. orientalis as the sister taxon of A. p. tasmani with both A. meleagris meleagris and A. m. orientalis lineacauda being distinct. In contrast to the 16S rRNA mtDNA data, the COI data placed A. g. gracilicauda as the sister taxon to these medium-bodied species; while the subspecies status of the small-bodied taxa A. l. lineatus and A. l. tristis is reaffirmed. Combined analysis of both gene fragments for Acontias taxa recovered the same clades as found using only COI data. Systematic affinities in Acontias are discussed. These results indicate that Acontias is more species rich than previously thought.  相似文献   

13.
We assess phylogenetic relationships within the polychaete family Hesionidae from morphological data combined with nucleotide data from 18S rDNA, 28S rDNA, 16S rDNA and COI. Parsimony and Bayesian analyses were performed on two data sets; the first was based on a more restricted set of terminals with both morphological and molecular data (17 ingroup terminals), while the second included additional taxa with morphological data only (25 ingroup terminals). The different sets of terminals yielded fully congruent results, as did the parsimony and the Bayesian analyses. Our results indicate high levels of homoplasy in traditionally used morphological characters in the group, and that Hesioninae, Gyptini and Gyptis are nonmonophyletic. Hesionini (mainly Hesione and Leocrates ), Psamathini (mainly Hesiospina , Micropodarke , Nereimyra , Psamathe and Syllidia ), Ophiodrominae (Gyptini and Ophiodromini) and Ophiodromini (mainly Heteropodarke , Ophiodromus and Podarkeopsis ) are monophyletic and agree with previous classifications, and Hesionini is probably the sister to all other hesionids. The placements of the small hesionids capricornia and Lizardia , the hydrothermal vent taxa Hesiodeira and Hesiolyra , and the newly described Hesiobranchia , remain uncertain.  相似文献   

14.
The superfamilies of Elateriformia have been in a state of flux since their establishment. The recent classifications recognize Dascilloidea, Buprestoidea, Byrrhoidea and Elateroidea. The most problematic part of the elateriform phylogeny is the monophyly of Byrrhoidea and the relationships of its families. To investigate these issues, we merged more than 500 newly produced sequences of 18S rRNA, 28S rRNA, rrnL mtDNA and cox1 mtDNA for 140 elateriform taxa with data from GenBank. We assembled an all‐taxa (488 terminals) and a pruned data set, which included taxa with full fragment representation (251 terminals); both were aligned in various programs and analysed using maximum‐likelihood criterion and Bayesian inference. Most analyses recovered monophyletic superfamilies and broadly similar relationships; however, we obtained limited statistical support for the backbone of trees. Dascilloidea were sister to the remaining Elateriformia, and Elateroidea were sister to the clade of byrrhoid lineages including Buprestoidea. This clade mostly consisted of four major lineages, that is (i) Byrrhidae, (ii) Dryopidae + Lutrochidae, (iii) Buprestoidea (Schizopodidae sister to Buprestidae) and (iv) a clade formed by the remaining byrrhoid families. Buprestoidea and byrrhoid lineages, with the exception of Byrrhidae and Dryopidae + Lutrochidae, were usually merged into a single clade. Most byrrhoid families were recovered as monophyletic. Callirhipidae and Eulichadidae formed independent terminal lineages within the Byrrhoidea–Buprestoidea clade. Paraphyletic Limnichidae were found in a clade with Heteroceridae and often also with Chelonariidae. Psephenidae, represented by Eubriinae and Eubrianacinae, never formed a monophylum. Ptilodactylidae were monophyletic only when Paralichas (Cladotominae) was excluded. Elmidae regularly formed a clade with a bulk of Ptilodactylidae; however, elmid subfamilies (Elminae and Larainae) were not recovered. Despite the densest sampling of Byrrhoidea diversity up to date, the results are not statistically supported and resolved only a limited number of relationships. Furthermore, questions arose which should be considered in the future studies on byrrhoid phylogeny.  相似文献   

15.
Comparative ultrastructural data have shown that at least two distinct groups exist within Carteria. Similarly, interpretations of variation in gross morphological features have led to the discovery of morphologically distinct groups within the genus. Partial sequences from the nuclear-encoded small- and large-subunit ribosomal RNA molecules of selected Carteria taxa were studied as a means of 1) testing hypotheses that distinct groups of species exist within the genus and 2) assessing monophyly of the genus. Parsimony analysis of the sequence data suggests that three Carteria species, C. lunzensis, C. crucifera, and C. olivieri, form a monophyletic group that is the basal sister group to all other ingroup flagellate taxa (including species of Chlamydomonas, Haematococcus, Stephanosphaera, Volvox, and Eudorina). Two other Carteria taxa, C. radiosa and Carteria sp. (UTEX isolate LB 762), form a clade that is the sister group to a clade that includes Haematococcus spp., Chlamydomonas spp., and Stephanosphaera. Thus, the sequence data support the interpretations of ultrastructural evidence that described two distinct Carteria lineages. Moreover, the sequence data suggest that these two Carteria groups do not form a monophyletic assemblage. Parsimony analysis of a suite of organismal (morphological, ultra-structural, life history, and biochemical) character data also suggest two distinct lineages among the five Carteria taxa; however, the organismal data are ambiguous regarding monophyly of these Carteria taxa. When the two independent data sets are pooled, monophyly of Carteria is not supported; therefore, the weight of available evidence, both molecular and organismal, fails to support the concept of Carteria as a natural genus.  相似文献   

16.
We present a molecular phylogeny of Nitidulidae based on thirty ingroup taxa representing eight of the ten currently recognized subfamilies. Approximately 10 K base pairs from seven loci (12S, 16S, 18S, 28S, COI, COII and H3) were used for the phylogenetic reconstruction. The phylogeny supports the following main conclusions: (i) Cybocephalidae are formally recognized as a distinct family not closely related to Nitidulidae and its constituent taxa are defined; (ii) Kateretidae are sister to Nitidulidae; (iii) Cryptarchinae are monophyletic and sister to the remaining nitidulid subfamilies; (iv) subfamily Prometopinae stat. res. is reinstated and defined, to accommodate taxa allied to Axyra Erichson, Prometopia Erichson and Megauchenia MacLeay; (v) Amphicrossinae, Carpophilinae and Epuraeinae are shown to be closely related taxa within a well‐supported monophyletic clade; (vi) tribal affinities and respective monophyly within Nitidulinae are poorly resolved by our data and must be more rigorously tested as there was little or no support for prior morphologically based tribes or genus‐level complexes; (vii) Nitidulinae are found to be paraphyletic with respect to Cillaeinae and Meligethinae, suggesting that they should either be subsumed as tribes, or Nitidulinae should be divided into several subfamilies to preserve the status of Cillaeinae and Meligethinae; (viii) Teichostethus Sharp stat. res. is not a synonym of Hebascus Erichson and the former is reinstated as a valid genus. These conclusions and emendations are discussed in detail and presented within a morphological framework.  相似文献   

17.
Two new ciliate species, Clevelandella lynni sp. n. and Nyctotherus galerus sp. n., were discovered in the hindgut of wood‐feeding panesthiine cockroaches. Their morphology was studied using standard methods, and their phylogenetic positions within the order Clevelandellida were determined using the 18S rRNA gene sequences. Clevelandella lynni is characterized by a prominent peristomial projection, a notched left body margin, a tear‐shaped to broadly ovoidal macronucleus, a karyophore attached to the right body margin, and by an adoral zone composed of on average 48 membranelles and extending about 51% of body length. The diagnostic features of N. galerus include a short posterior body projection, a spherical to broadly ellipsoidal macronucleus, a karyophore attached to the right and left body margins, refractile bodies densely packed anterior to the macronucleus, and an adoral zone composed of on average 57 membranelles and extending about 70% body length. The order Clevelandellida was consistently depicted as monophyletic in 18S rRNA gene phylogenies. Nyctotherus galerus was placed in the paraphyletic family Nyctotheridae, as sister taxon to all other Nyctotherus and Clevelandella species isolated from cockroaches. Clevelandella lynni fell in the monophyletic family Clevelandellidae, as sister taxon to C. panesthiae KC139718 but with very poor statistical support.  相似文献   

18.
外群选择对隧蜂科(膜翅目:蜜蜂总科)系统重建的影响   总被引:1,自引:0,他引:1  
外群用于给树附根和推断祖先性状状态。通常,来自内群的姐妹群中的多个分类单元被共同选择作为外群。为了在经验上验证这一方法, 我们采用了3种外群选择策略: 姐妹群中的单一分类单元, 姐妹群中的多个分类单元和连续姐妹群中的多个分类单元。以隧蜂科(膜翅目: 蜜蜂总科)的系统发育重建为例, 我们评估了这3种策略对树拓扑结构的影响, 包括最大似然树、 最大简约树和贝叶斯树。初步结果表明: 相比其他两种策略, 采用姐妹群中的多个分类单元作为外群更有利于系统发育重建得到现已被广泛认可的隧蜂科系统发育关系; 相比最大似然法和贝叶斯法, 虽然隧蜂科系统发育关系没有被很好地解决, 但最大简约法在不同外群选择策略下得到了较为一致的拓扑结构  相似文献   

19.
Phylogenetic analyses of the leech family Macrobdellidae were accomplished with all nominal species in the family save one. A total of 17 specimens in nine ingroup species were analysed, along with four outgroup taxa. Twenty-two morphological characters based on jaw dentition, sexual anatomy, and external morphology failed to provide a resolution for many of the relationships in the family. DNA sequence data from nuclear 18S rDNA, nuclear 28S rDNA, mitochondrial 12S rDNA, and mitochondrial cytochrome c oxidase subunit I were examined separately and in combination with morphological characters. The resulting combined analysis strongly corroborated the placement of the genus Philobdella within the family Macrobdellidae and as sister to a monophyletic genus Macrobdella , the typical North American medicinal leeches. Furthermore, sequence divergences among these taxa confirmed the existence of two species, Philobdella gracilis and P. floridana , readily distinguishable on the basis of jaw dentition .  相似文献   

20.
Abstract A molecular phylogeny of the fungus gnat family Mycetophilidae based on the nuclear 18S, 28S, and the mitochondrial 16S rRNA genes is presented. The total alignment included 58 taxa and 1704 bp. The family was recovered as monophyletic in parsimony and Bayesian analyses. In the Bayesian analysis, Mycetophilinae and its two tribes, Mycetophilini and Exechiini, were monophyletic with good statistical support. The subfamily Mycomyinae was found consistently in a sister‐group relationship to Mycetophilinae. Gnoristinae was rendered paraphyletic, subtending Mycomyinae and Mycetophilinae. Within Gnoristinae, the genera Coelosia Winnertz, Boletina Staeger, Gnoriste Meigen group with Docosia Winnertz, usually considered to be a member of Leiinae. No support was found for the monophyly of the subfamilies Sciophilinae and Leiinae.  相似文献   

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