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中国的脊棱齿象属(Stegolophodon)化石 总被引:4,自引:2,他引:4
剑齿象属 Stegodon 起源于脊棱齿象属 Stegolophodon,两者都是亚洲大陆晚新生代的特有动物,本文讨论两属中一些种的性质和分类位置问题,并记述了药铺脊棱齿象 Stegolophodon officinalis 的新材料. 相似文献
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关于栽培植物的命名问题 总被引:2,自引:0,他引:2
介绍了栽培植物命名规则,包括其分类等级和命名体系。简要介绍了《中国梅花品种图志》、《中国桂花品种图志》等著作的作者提出和遵循的关于栽培植物品种中文名命名的原则和意见,并对我国栽培植物品种中文名命名中存在的主要问题进行了简要评述。 相似文献
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性双型的特征通常被认为产生于种内争夺交配优先权的斗争。例如,现生和化石的雄性长鼻类动物具有较大的体型和较粗壮的上门齿。本研究阐释了如下现象:化石象型类动物(Elephantiformes,长鼻类的主要类群)一些性双型特征与其进化历史具有相关性,而与性别竞争并非直接相关。在中新世的葛氏铲齿象(Platybelodon grangeri)和狭齿嵌齿象(Gomphotherium angustidens)中,雄性比雌性倾向于具有进化中更进步的特征,如同雄性在进化中领先雌性一步。这种现象可能与雌性偏好的机制相耦合。在象型类动物进化的早期(繁荣期),性别选择压促使雄性比雌性产生更加显著的进步特征;然而,在它们进化的晚期(衰退期),性别选择压似乎减弱,性别的异时进化也减少。这种新的发现或许在大型有蹄类的演化过程中有一定的普遍意义,因为那些繁荣的类群中通常性双型显著,如鹿科和牛科;而衰落的类群中通常性双型不显著。 相似文献
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博白油茶和红皮糙果茶分类学问题的讨论 总被引:4,自引:0,他引:4
通过对由原产地引种的博白油茶 (Camellia gigantocarpa Hu et Huang)和红皮糙果茶 (C.crapnel-liana Tutcher)成长植株的形态、花、果实以及馆藏相关标本的详细比较和观察 ,认为这两个种存在着显著的差异 :博白油茶树皮被灰绿色的粉末 ,红皮糙果茶树皮被砖红色的粉末 ;博白油茶侧脉 9~ 1 0对 ,叶缘具细锯齿 ,叶下偶见微毛 ;红皮糙果茶的侧脉 7~ 8对 ,叶缘具浅细圆齿 ,叶下永远无毛 ;博白油茶花瓣数目 6~ 7枚 ,为倒卵形到宽倒卵形 ,花瓣基部连生仅 2 mm;红皮糙果茶花瓣数目常为 8~ 9枚 ,甚至更多 ,为倒卵形到窄倒卵形 ,花瓣基部连生达 4 mm;博白油茶的雄蕊花丝基部连生仅 2 mm;红皮糙果茶的雄蕊花丝基部连生达 5~6 mm。因而应该将博白油茶 (C. gigantocarpa Hu et Huang)看作一个独立的种。 相似文献
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新疆寒武纪早期单壳类软体动物化石分类学与生物地层学 总被引:2,自引:0,他引:2
作者系统描述了新疆阿克苏-乌什地区下寒武统玉尔吐斯组中上部单壳类软体动物化石10属10种,其中包括3个新种、3个老种和4个未定种,它们是Shabaktiella multiformis sp.nov.,Ilsanella acuta sp.nov.,Xianfengella yuertusiensis sp.nov.,Parcaconus xinjiangensis,Protostenotheca xinjiangensis,Aldanella attlebo-rensis,Obtusoconus sp.,Yochelcionella sp.,Bemella sp.和Mellopegma sp..上述10个属种基本上代表了玉尔吐斯组单壳类软体动物的面貌特征.文中介绍了本研究区10个属和属级以上分类系统在国际学术界的意见分歧后,重申了以壳的对称性和有无肌痕确定纲级界线的最佳分类原则,提出了应用壳型划分目级分类单元和口缘形状、壳顶与口缘的相对位置划分科级分类单元的可行性和有效性,但是不能接受把所有单板状软体动物化石通常被归入单板纲的做法,因为寒武纪早期一些单板状软体动物化石不一定符合单板纲的真实含义.文中还回顾了近二十年来建立的始单板纲(Eomonoplacophora)(Missarzhevsky,1989),太阳女神螺纲(Helcionelloida),背壳肌纲(Tergomya)(Peel,1991a,b)和似腹足纲(Paragastropoda)(Linsley & Kier,1984)等纲级的新概念.还有一些早期软体动物专家将许多单板状(包括帽状和螺旋状)化石归入单板纲(Runnegar et al.,1976,1985),而另有一些中青年软体动物专家继承传统理念,将它们归入了腹足纲(Parkhaev in.Alexander et al.,2001).钱逸和本格森将早期单壳类软体动物化石分成了五大形态类别,未确定科级以上分类单元名称(Qian & Bengtson,1989).总之,目前纲级分类单元界线不清,目级以下分类单元十分混乱,在没有全面清理早期单壳类软体动物百余个属和属级以上分类单元之前,是难以统一本文研究的早期单壳类软体动物10个属和属级以上分类系统.我们认为在确定属级以上分类系统及其与之密切相关的演化谱系关系时,不是利用理论前提,而是在不间断的剖面上对单壳类软体动物化石进行逐层采集并对其构造要素的详细研究,才能使得出的结论和提出的新分类系统发生错误的几率最小.文中还归纳和总结了本研究区玉尔吐斯组中上部单壳类软体动物群面貌的六大特点,其中二点最重要:1)该动物群与梅树村期微软体动物群的面貌有明显的差别,它缺失了梅树村期微软体动物群中最原始、最特征、最丰富的类群,如笠帽状的马哈螺类化石Maikhanella,Purella等和螺旋状的始旋螺类化石Archaeospira等.但是该动物群面貌却与邻区的哈萨克斯坦Atdabanian期的微软体动物和我国峡区西蒿坪动物群面貌接近,出现了许多相同或相似的属种,如Shabaktiella,Mellopegma,Aldanella,Yochelcionella等.2)该动物群共生有全球分布的相当于筇竹寺期的标准化石,如原牙形类Gapparodus,Amphigeisina,Hagionella等,有口唇并有背腹分异和复杂口盖的软舌螺类Microconus,Pachytheca等,具有肉茎孔和铰合面的有铰腕足类和像Obolus那样的原始无铰腕足类,有各种形态类型的金臂虫Dabashanella,Liangshanella等,还有可疑的三叶虫颊刺等.上述信息足以说明玉尔吐斯组中上部地层时代应属筇竹寺期而非梅树村期,从而解决了长期以来有关玉尔吐斯组时代归属的争议. 玉尔吐斯组单壳类软体动物群的研究,再次证实了寒武纪生命大爆发期间,早期单壳类软体动物与小壳动物群一起经历了三次大发展和三次大绝灭事件.这在早期单壳类软体动物化石分类学、生物地层学和早期演化史上均有较高的科学价值. 相似文献
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化石介形类分类依据--壳体形态,包括壳体的大小、形状、装饰和诸如毛孔、叠覆、似犁状构造、喙、铰合构造等构造特征都与介形类的栖息环境,包括地理、气候(季节、纬度等)、水体的深度、化学性质和稳定程度,食物的富集程度和群落的组成及个体数量以及性别息息相关.因此,正确理解介形类的形态学特征及其功能学,不仅能揭示介形类的生活习性,推测化石介形类的生活环境,从而为古环境和古群落生态重建提供依据,而且可以提高化石介形类个体发育、系统分类和演化研究结果的可靠性. 相似文献
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报道了甘肃天水地区武山县四门镇南峪村地点发现的一件残破的未成年维曼嵌齿象(Gomphotherium wimani)下颌,标本保存有完整的p3,dp4,m1齿列。颊齿齿冠显示出嵌齿象属(Gomphotherium)的一些进步特征,例如齿脊前后压缩,齿谷宽阔,副齿柱后中心小尖凸显,中附锥和中心小尖趋于分裂,有弱的白垩质发育,符合维曼嵌齿象的鉴定特征。维曼嵌齿象此前发现于甘肃的中中新统,而南峪村地点的含化石地层可与周围其他地点的中中新统对比,因此,南峪村地点维曼嵌齿象层位的地质时代为中中新世。同时,结合孢粉学研究的结果,可能说明中中新世时期,天水地区气候温暖湿润,适宜低齿冠的哺乳类如嵌齿象等动物生存。 相似文献
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Origins, taxa, names and meanings 总被引:1,自引:0,他引:1
Olivier Rieppel 《Cladistics : the international journal of the Willi Hennig Society》2008,24(4):598-610
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Eight names in five genera Delphinium (Ranunculaceae), Lindernia and Mimulicalyx (Scrophulariaceae), Sorbus and Spiraea (Rosaceae) from China were not validly published because two gatherings were simultaneously designated as types in the protologues,
or were simultaneously cited, without indicating the type in the protologues. These eight names are validated here, with one
specimen designated as the holotype. 相似文献
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A contribution towards resolving the nomenclature of Citharexylum (Verbenaceae): typification of names linked to South American taxa 下载免费PDF全文
During ongoing taxonomic studies in the genus Citharexylum (Verbenaceae), twenty names were found in need of typification or typification clarifications. Fourteen names (C. andinum, C. herrerae, C. ilicifolium, C. kunthianum, C. laetum, C. myrianthum var. acuminatum, C. myrianthum var. rigidum, C. pernambucense, C. poeppigii, C. quercifolium, C. solanaceum, C. solanaceum var. macrocalyx, C. surrectum and C. weberbaueri) are here lectotypified, and epitypes are selected for three names (C. herrerae, C. kunthianum and C. pernambucense). Neotypes are designated for the names C. berteroi, C. broadwayi and C. coriaceum. Furthermore, updates and supporting information for three names already typified by Harold Moldenke (C. macrochlamys, C. punctatum and C. subthyrsoideum) are provided. 相似文献
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化石植物中文名的现状、问题与建议 总被引:1,自引:0,他引:1
化石植物的中文名,即化石植物学名的中文译名,在古植物学、植物演化生物学专业领域和科学普及等方面起着重要的作用。然而,长期以来对化石植物中文名重视程度不够且拟订时缺乏统一的标准,导致各种文本中化石植物的中文名比较混乱,不利于古植物学知识的传播及科学普及。本文通过统计中文古植物学综合性文献和教材中的化石植物中文名,梳理出化石植物中文名拟订方面出现的一些包括同物异中文名、中文名重名、音译拗口和存在生僻字的使用等常见问题。针对这些问题,本文提出应尽快制定出一套规范统一的化石植物中文名拟定方案,编写和出版化石植物拉汉词典及相应网络查询系统等,从而统一和规范化石植物的中文名,同时也可为化石动物中文名的拟订方案提供相关参考。 相似文献
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浅谈传粉生物学中几个术语的含义及其中文译名 总被引:8,自引:3,他引:8
准确理解外来的专业术语并给予合适的中文译名,不仅有助于推动学科的发展,而且有利于同行之间的交流。传粉生物学是近年来在我国迅速发展的一个生态学与进化生物学的分支领域。本文讨论了该学科中的几个重要术语的含义和它们的中文译名,建议将pollen discounting和seed discounting译为“花粉折损”和“种子折损”,herkogamy译为 “雌雄异位”,trade-off译为“权衡”。 相似文献
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F. Pleijel G. W. Rouse 《Journal of Zoological Systematics and Evolutionary Research》2003,41(3):162-174
An introduction is provided to the literature and to issues relating to phylogenetic nomenclature and the PhyloCode, together with a critique of the current Linnaean system of nomenclature. The Linnaean nomenclature fixes taxon names with types, and associates the names with ranks (genus, family, etc.). In phylogenetic nomenclature, names are instead defined with reference to cladistic relationships, and the names are not associated with ranks. We argue that taxon names under the Linnaean system are unclear in meaning and provide unstable group–name associations, notwithstanding whether or not there are agreements on relationships. Furthermore, the Linnaean rank assignments lack justification and invite unwarranted comparisons across taxa. On the contrary, the intention of taxon names in phylogenetic nomenclature is clear and stable, and the application of the names will be unambiguous under any given cladistic hypothesis. The extension of the names reflects current knowledge of relationships, and will shift as new hypotheses are forwarded. The extension of phylogenetic names is, therefore, clear but is associated to (and thus dependent upon) cladistic hypotheses. Stability in content can be maximized with carefully formulated name definitions. A phylogenetic nomenclature will shift the focus from discussions of taxon names towards the understanding of relationships. Also, we contend that species should not be recognized as taxonomic units. The term ‘species’ is ambiguous, it mixes several distinct classes of entities, and there is a large gap between most of the actual concepts and the evidence available to identify the entities. Instead, we argue that only clades should be recognized. Among these, it is useful to tag the smallest named clades, which all represent non-overlapping groups. Such taxa – LITUs (Least Inclusive Taxonomic Units) – are distinguished from more inclusive clades by being spelled with lower-case initial letter. In contrast to species, LITUs are conceptually straightforward and are, like other clades, identified by apomorphies. 相似文献
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When scientists use a taxon name like Mammalia, it is important that they talk about the same thing. But, what does it mean to be the same thing in different phylogenetic hypotheses? And, how is taxonomic reference maintained across hypotheses? Here, we discuss the differences between real and hypothetical clades, and how such a distinction relates to the sameness problem. Since hypotheses influence how we perceive things and pursue science, we find it important to have a functioning nomenclatural system for clades as perceived in phylogenetic hypotheses. As a solution to the sameness problem for such clades, we argue that a taxon name does not primarily refer to a single clade that somehow mirror the reality of branches in the tree of life. Instead we suggest that a taxon name refers to a set, or natural kind, of counterfactual and reconstructed clades. 相似文献
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根据保存于中国科学院华南植物园植物标本馆(IBSC)、中国科学院植物研究所植物标本馆(PE)和四川大学生命科学学院植物标本馆(SZ)复份标本的研究,对中国胡颓子科(Elaeagnaceae)胡颓子属(Elaeagnus)的6个植物名称作出后选模式指定。 相似文献
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2020年中国共发表高等植物新分类群359个, 其中新属21个、新种312个、新亚种6个、新变种14个、新变型6个; 发表新组合(等级) 217个, 新名称11个; 发表国家级新记录48个; 将85个名称处理为65个名称的异名; 对14个名称进行了应用订正; 新指定后选(新)模式物种147个; 还新发现多年未曾发现的物种2个, 排除物种分布3个。新发表的物种中, 苔类植物门有3个、藓类植物门3个、蕨类植物门6个、裸子植物门1个新杂交种、被子植物门299个。这些新物种中, 有86个发表的同时提供了详细的分子证据, 78个在发表时就依据IUCN标准被评估处于受威胁的状态。云南、西藏、广西和四川等西南4省区发表新物种最多, 占全国新物种发表总数的2/3; 新物种发现密度最高的省级行政单位是云南、海南、台湾、广西和浙江等省区; 墨脱县是新物种发现数量最多的县级行政单位。2020年中国高等植物净新增294个分类群, 占全国总数的0.79%, 313个高等植物名称发生变动, 占全国总数的0.84%。 相似文献
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Dhanushka N. Wanasinghe R. Jeewon E. B. Gareth Jones Saranyaphat Boonmee Saithong Kaewchai Ishara S. Manawasinghe Saisamorn Lumyong Kevin D. Hyde 《Mycological Progress》2018,17(5):571-590
Palm fungi are highly diverse in the tropical regions of Asia. Recent investigations on these palmicolous fungi have led to the collection of astrosphaeriella-like taxa from Calamus, Caryota, and Licuala species in Thailand (Chiang Rai and Narathiwat provinces) and southwest China (Yunnan Province). This study characterizes fungal taxa, which are new to science, based on morphological examination and concatenated DNA sequence data, to infer their familial relationships. Morphological comparisons reveal six new species, viz. Astrosphaeriellopsis caryotae, Fissuroma calami, F. caryotae, Neoastrosphaeriella sribooniensis, Pithomyces caryotae, and P. licualae.Their similarities and differences to other extant species are discussed. The phylogenetic results indicate that all of these new taxa belong to Aigialaceae and Astrosphaeriellaceae (Pleosporales) and support their establishment. Astrosphaeriellopsis is assigned to Astrosphaeriellaceae and the family is amended in order to accommodate both coelomycetous and hyphomycetous asexual morphs. A generic key is presented for Astrosphaeriellaceae to delimit Astrosphaeriella, Astrosphaeriellopsis, Pteridiospora, and Pithomyces. Asexual morph connections of Pithomyces caryotae and P. licualae are established from axenic cultures derived from single ascospores. DNA-based sequence data supports the establishment of our new species; however, the affinities of Astrosphaeriella tornata to other Astrosphaeriella and Pithomyces species are unclear and warrant further investigations with increased taxon sampling. 相似文献