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The Nannomecoptera are among the most enigmatic and controversial taxa of endopterygote insects, the phylogenetic resolution of which is crucial to understanding the evolution of neopteran insects. Once considered a subordinate lineage within the Mecoptera, renewed interest in nannochoristids has been prompted by evidence that the Nannomecoptera are not admissible to the clade of extant scorpion flies but are more likely to belong to the clade Siphonaptera + Nannomecoptera + Diptera. The overarching purpose of the present account is to provide novel and extensive morphological character traits in addition to those already existing for adult structures. The aim is to determine if these traits support molecular data sets that have been suggested elsewhere to clarify the phyletic position of Nannochoristidae. This account focuses on nannomecopteran larvae, which unlike those of other mecopterans have received little attention. Thus, the thrust of this investigation is to provide detailed anatomical data on nannochoristid larvae for a targeted inquiry into their phylogenetic affinities. The described characters are discussed and presented in a data matrix comprising representatives of all endopterygote orders. While the study is based primarily on the New Zealand species Nannochorista philpotti, it is proposed that all nannomecopteran larvae will prove to be similar to this taxon in most if not all structural features of significance to a higher-level phylogenetic context.  相似文献   
2.
Seven species and one sub-species of Mecoptera are aquatic as larvae and pupae. All aquatic species are classified in two genera of the family Nannochoristidae and have very restricted geographic ranges, with three species confined to extreme southern South America, three species and one sub-species confined to New South Wales or Tasmania in Australia, and one species confined to the South Island of New Zealand. Guest editors: E. V. Balian, C. Lévêque, H. Segers & K. Martens Freshwater Animal Diversity Assessment  相似文献   
3.
External and internal head structures of Nannochorista species were examined and described in detail. The characters are discussed with regard to their functional and phylogenetic implications. The structure of the mouthparts indicates that adults of Nannochorista feed on fluids. The loss of the mandibular muscles and the precerebral pharyngeal dilators are presumptive autapomorphies of the genus. A possible clade comprising Nannomecoptera, Siphonaptera and Diptera is supported by the presence of a labral food channel, the absence of the galea, a sheath for the paired mouthparts formed by the labium, very strongly developed labial palp muscles and cibarial dilators, and the presence of a well‐defined postcerebral pharyngeal pumping chamber. Closer affinities of Nannomecoptera with Diptera are suggested by the presence of a unique sensorial groove on the third maxillary palpomere. Further potential synapomorphies are the presence of a frontal apodeme and a primarily lamelliform mandible without teeth. The presence of a salivary channel on the laciniae and a subdivided labrum are shared derived features of Nannochorista and Siphonaptera. A derived condition present in Mecoptera including Boreidae but excluding Nannochoristidae is the secretion with a strongly developed intrinsic muscle of the salivary duct. The loss of the lateral labral retractor, the cranial muscle of the cardo, and of two of the three premental retractors, and the absence of transverse epipharyngeal muscles are potential autapomorphies of Antliophora. The formation of a maxillolabial complex is a possible synapomorphy of Hymenoptera and Mecopterida.  相似文献   
4.
内蒙古道虎沟中侏罗世小蝎蛉科(昆虫纲,长翅目)昆虫化石   总被引:2,自引:0,他引:2  
描述小蝎蛉科化石1新属2新种:多脉原始小蝎蛉Protochoristella polyneura gen.et sp.nov.,美丽原始小蝎蛉P.formosa gen.et sp.nov..简要讨论了小蝎蛉科的起源与演化.所有化石标本均采于内蒙古宁城道虎沟中侏罗世九龙山组地层,模式标本现保存于首都师范大学生命科学学院.  相似文献   
5.
External and internal thoracic structures of Nannochorista spp. are described in detail. The results are compared with conditions found in other endopterygote taxa, especially in members of Antliophora. Seventy-seven characters potentially useful for phylogenetic reconstruction are discussed, coded, presented as a data matrix and analysed cladistically. The thorax of Nannochorista shows a number of plesiomorphic characters compared with other mecopterans (except for Merope ) and members of the other antliophoran groups (e.g. presence of prospina and associated muscles). No specific affinities of thoracic features of Nannochoristidae and Diptera were found. The cladistic analysis results in strongly supported Antliophora (e.g. intraprofurcal muscle and ventral pleural arms present; bundle of M. mesonoto-pleuralis posterior originates on pleural arm). The thoracic characters do not support the monophyly of Mecoptera. This is possibly an artefact of the analysis. Several potential thoracic autapomorphies of the order are inapplicable in Boreidae, Siphonaptera and Diptera. Boreidae and Siphonaptera share a suite of characters related with flightlessness and are retrieved as sistertaxa when characters associated with wing reduction are predefined as irreversible. Merope appears exceptionally plesiomorphic in its thoracic morphology. Pistillifera (excluding Meropidae) and Panorpoidea (Panorpidae + Panorpodidae) are supported as clades. Due to the strongly modified thoracic morphology of Siphonaptera, the position of this group remains uncertain. The phylogenetic reconstruction using thoracic features alone is clearly impeded by far reaching modifications in Diptera in correlation with an advanced type of anteromotorism, and complex suites of reductional features in the secondary wingless forms.  相似文献   
6.
The win structure of the New Zealand nannochoristid currently known as Microchorista philgotti: (Tillyard, 1917) is described and discussed. Tubular wing vein sclerotizations are developed in the uper win cuticle only. Shortening of the hindwing CuP-A anastomosis to a single point cannot ge uphed as a nannochoristid autapomorphy. Absence of the Rs3-Rs4 crossvein (the diagnostic character for Microchorista) and, perhaps, presence of specialized microtrichia patches on the fore wing are autapomorphic of the New Zealand species. Since the genus Nannochorista, comprising the Australian/Tasmanian and S. American nannochoristids, according to available evidence is paraphyletic in terms of Microchorista the latter is synonymized with the former.  相似文献   
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