现生鸟类和孔子鸟(Confuciusornis)叉骨软骨的研究:初步分析以及对中生代鸟类飞行方式的启示（英文）

飞行的早期演化是古生物研究的热点问题之一。现生鸟类演化出多种不同飞行方式,然而对中生代鸟类飞行方式的研究亟需寻找具有指示意义的指标。骨骼与关节组织尤其是乌喙骨-叉骨关节是实现鸟类飞行功能的重要组成,因此其关节的组织形态可能有助于反映现生鸟类的飞行方式。鸟类膜质骨中的次级软骨受到表观遗传的重要影响,只能在关节受到肌肉运动刺激的情况下形成,因此能够反映鸟类关节的形成力学环境;对三种不同飞行方式的现生鸟类(珠颈斑鸠、树麻雀和普通楼燕),以及热河生物群中最为常见的古鸟类之一孔子鸟(Confuciusornis)的叉骨乌喙骨关节的组织学特征进行了分析,显示在所有三种现生鸟类中,叉骨与乌喙骨之间均存在可动关节,并且在叉骨上存在次级软骨。而孔子鸟的叉骨上也存在次级软骨,这是次级软骨组织在中生代鸟类叉骨化石中的首次报道。进一步分析发现,不同现生鸟类物种的次级软骨组织形态存在差异,还需更多数据建立相关形态功能关系以便用于帮助推断中生代鸟类的飞行方式。     

辽宁中生代鸟类综述

本文对发现于辽宁中生代地层中的鸟类化石,进行了简单的总结。化石的系统分析表明,从晚侏罗世到早白垩世在这一地区存在两个亚纲的鸟类分子：蜥鸟亚纲（Sauriurae）和今鸟亚纲（Ornithurae）。其中,蜥鸟亚纲的成员不仅数量居多,而且存在较大的分异。今鸟亚纲的分子则种类和数量都相对较少。辽西中生代鸟类的大量出现,除了鸟类自身的发展原因外,晚侏罗世到早白垩世这一地区适宜的生态环境也为鸟类的繁荣提供了必要的条件。辽西地区陆相中生代地层义县组和九佛堂组的时代分别为晚侏罗世和早白垩世。     

龙羊峡地区鸟类现状及水库蓄水后演化预测

龙羊峡水库是高寒、干旱、多风沙地区的一座大型水库,它的建成除具有发电、防洪、灌溉等效益外,还将改善库区周围环境,促进农、林、牧、渔业发展的综合效能。从鸟类学的角度预测水库环境影响评价工作还是一种新的尝试,这次考察只不过是一个开端,有待进一步完善。     

孔子鸟与“中华龙鸟”

孔子鸟与“中华龙鸟”董枝明１９９６年末到１９９７年之春,世界多家新闻媒体相继报道中国辽宁省朝阳地区产出的２种原始的“鸟类”化石,孔子鸟（Ｃｏｎｆｕｃｉｕｓｏｒｎｉｓ）和“中华龙鸟”（Ｓｉｎｏｓａｕｒｏｐｔｅｒｙｘ）。孔子鸟的研究者是中国科学院古脊椎动...     

鸟类起源与演化百问百答（上）

一、起源篇１ 鸟类起源于恐龙吗 ?目前国际上多数学者已同意鸟类确实起源于一类小型的兽脚类恐龙 ,但仍有一些学者持不同看法。２ “鸟就是恐龙 ,恐龙就是鸟”这句话对吗 ?如果承认鸟类起源于恐龙 ,那么说鸟就是恐龙就相当于说人是哺乳动物 ,从系统关系和分类的角度来讲 ,这句话基本算对 ,但严格来说 ,也不对 ,因为鸟类和恐龙毕竟存在差别正如人和哺乳动物存在很大不同的道理一样 ;但是说恐龙就是鸟则相当于说哺乳动物就是人 ,显然是不对的。３ 鸟类的起源有几大假说 ?历史上关于鸟类的起源 ,主要存在过三种主要的假说 :一是鸟类的恐龙起源…     

对于早期鸟类起源与演化过程中一些疑问的个人见解

鸟类起源问题在学术界仍然存在分歧 ,现在大多数古生物学家都支持鸟类起源于恐龙之说。虽然化石证据表明恐龙和早期鸟类之间确实存在很多相似之处 ,但是仍有一些疑问无法得到合理解释 ,那么鸟类是否起源于恐龙呢？很多学者认为霸王龙和驰龙类同鸟类具有较近的亲缘关系 ,但是却无法解释这类进步的恐龙为何出现在比中生代早期化石鸟类更晚的地层之中？笔者认为霸王龙及驰龙类的始祖同鸟类最终始祖之间可能存在较近的亲缘关系 ,可以认为霸王龙及驰龙类在它们的演化过程中除体型以外在其他方面同其始祖之间并无较大区别 ,笔者认为霸王龙可能处于…     

鸟类的飞行与翼的适应性演化

在现生生物中,具有飞行能力的动物无疑只有鸟类、昆虫和蝙蝠。翅膀是鸟类由陆地飞向天空的工具,鸟类特有的飞行运动方式足在神经系统的控制下由骨骼、肌肉和羽片共同完成的。它的结构和运动方式区别于其他两种动物的飞行器。     

HIGH RATES OF EVOLUTION PRECEDED THE ORIGIN OF BIRDS

The origin of birds (Aves) is one of the great evolutionary transitions. Fossils show that many unique morphological features of modern birds, such as feathers, reduction in body size, and the semilunate carpal, long preceded the origin of clade Aves, but some may be unique to Aves, such as relative elongation of the forelimb. We study the evolution of body size and forelimb length across the phylogeny of coelurosaurian theropods and Mesozoic Aves. Using recently developed phylogenetic comparative methods, we find an increase in rates of body size and body size dependent forelimb evolution leading to small body size relative to forelimb length in Paraves, the wider clade comprising Aves and Deinonychosauria. The high evolutionary rates arose primarily from a reduction in body size, as there were no increased rates of forelimb evolution. In line with a recent study, we find evidence that Aves appear to have a unique relationship between body size and forelimb dimensions. Traits associated with Aves evolved before their origin, at high rates, and support the notion that numerous lineages of paravians were experimenting with different modes of flight through the Late Jurassic and Early Cretaceous.     

孔子鸟(Confuciusornis)骨骼微观组织结构初步研究

基于孔子鸟（Confuciusornis）股骨骨骼的微观组织结构与现生鸟类的相似性,认为孔子鸟具有较高而恒定的生长率,其新陈代谢可能已进化到相当高的水平,这种较高的代谢水平的起源要晚于鸟类的系统起源．鸟类骨骼内部的组织结构特征与骨骼外部的形态特征的进化是不同步的。孔子鸟等的祖先类型应是一生长速率较低而不恒定的、较原始的爬行动物。     

A NEW BASAL LINEAGE OF EARLY CRETACEOUS BIRDS FROM CHINA AND ITS IMPLICATIONS ON THE EVOLUTION OF THE AVIAN TAIL

Abstract:  We report on a new Early Cretaceous bird from China that sheds significant light on the evolutionary transition between primitive birds with a long bony tail and those with a short tail ending in a pygostyle. A cladistic analysis of basal birds supports the placement of the new fossil as the sister-taxon of all pygostylians. Possessing a unique hand morphology with a phalangeal formula of 2-3-3-x-x and a reduced number of caudal vertebrae lacking a pygostyle, the new specimen reveals anatomical information previously unknown and increases the taxonomic diversity of primitive, non-pygostylian birds. We infer from the specimen that during the evolution of the avian tail, a decrease in relative caudal length and number of vertebrae preceded the distal fusion of caudals into a pygostyle.     

从新的古生物学及今生物学资料看羽毛的起源与早期演化(英文)

近年来关于羽毛和羽状皮肤衍生物的研究极大促进了我们对羽毛起源与早期演化的理解。结合最新的古生物学与今生物学资料,对一些保存了皮肤衍生物的非鸟恐龙标本进行观察研究,为这个重要的进化问题提供了新见解。推测羽毛的演化在鸟类起源之前就以下列顺序完成了5个主要的形态发生事件:1)丝状和管状结构的出现;2)羽囊及羽枝脊形成;3)羽轴的发生;4)羽平面的形成;5)羽状羽小支的产生。这些演化事件形成了多种曾存在于各类非鸟初龙类中的羽毛形态,但这些形态在鸟类演化过程中可能退化或丢失了;这些演化事件也产生了一些近似现代羽毛或者与现代羽毛完全相同的羽毛形态。非鸟恐龙身上的羽毛有一些现代羽毛具有的独特特征,但也有一些现生鸟羽没有的特征。尽管一些基于发育学资料建立的有关鸟类羽毛起源和早期演化的模型推测羽毛的起源是一个全新的演化事件,与爬行动物的鳞片无关,我们认为用来定义现代鸟羽的特征应该是逐步演化产生的,而不是突然出现。因此,对于羽毛演化而言,一个兼具逐步变化与完全创新的模型较为合理。从目前的证据推断,最早的羽毛既不是用来飞行也不是用来保暖,各种其他假说皆有可能,其中包括展示或者散热假说。展开整合性的研究有望为羽毛的起源问题提供更多思路。     

THE EVOLUTION OF SPERM SIZE IN BIRDS

Sperm size varies enormously among species, but the reasons for this variation remain obscure. Since it has been suggested that swimming velocity increases with sperm length, earlier studies proposed longer (and therefore faster) sperm are advantageous under conditions of intense sperm competition. Nonetheless, previous work has been equivocal, perhaps because the intensity of sperm competition was measured indirectly. DNA profiling now provides a more direct measure of the number of offspring sired by extrapair males, and thus a more direct method of assessing the potential for sperm competition. Using a sample of 21 species of passerine birds for which DNA profiling data were available, we found a positive relation between sperm length and the degree of extrapair paternity. A path analysis, however, revealed that this relationship arises only indirectly through the positive relationship between the rate of extrapair paternity and length of sperm storage tubules (SSTs) in the female. As sperm length is correlated positively with SST length, an increase in the intensity of sperm competition leads to an increase in sperm length only through its effect on SST length. Why females vary SST length with the intensity of sperm competition is not clear, but one possibility is that it increases female control over how sperm are used in fertilization. Males, in turn, may respond on an evolutionary time scale to changes in SST size by increasing sperm length to prevent displacement from rival sperm. Previous theoretical analyses predicting that sperm size should decrease as sperm competition becomes more intense were not supported by our findings. We suggest that future models of sperm-size evolution consider not only the role of sperm competition, but also how female control and manipulation of ejaculates after insemination selects for different sperm morphologies.     

辽西中生代鸟类跗跖骨测量数据的统计分析及意义

跗跖骨是鸟类后肢骨骼的重要组成之一,其形态特征对恢复鸟类的行为和习性具有重要的指示意义。本文以鸟类的跗跖骨为研究对象,共观察了200余例有代表性的现生鸟类标本,并对其中15个目中的154例标本进行了多组数据的测量。还将跗跖骨各形态特征进行量化分析研究,引入相关分析和因子分析等统计分析方法。对现生鸟类跗跖骨5组(12个)变量进行分析,研究各变量间的相关程度,对变量进行主成分分析,提取出2个主成分,其中第1主成分包括第Ⅱ,Ⅲ,Ⅳ三个跖骨的宽度变量;第2主成分包括第Ⅱ跖骨滑车相对于第Ⅲ跖骨滑车的上下及前后位置两变量,以及第Ⅳ跖骨滑车相对于第Ⅲ跖骨滑车的前后位置变量。对这6个变量的分析表明,它们对于区别鸟类的栖息习性具有显著的指示作用。通过对在中国(辽西为主)已发现的25例中生代鸟类跗跖骨远端4个变量的统计分析,表明它们同样具有区别树栖和地栖鸟类的显著意义,而且分析的结果与参考鸟类其他特征(如爪的形态、脚趾的比例等)所得出的结论基本一致。     

从c-mos和12S rRNA基因序列探讨现生鸟类早期历史和三趾鹑类的系统地位

通常认为古腭型鸟类处在现生鸟类系统进化树的基部,最近的分子水平研究则认为今腭型鸟类中雀形目种类构成了现生鸟类中一个最古老的支系.本研究通过对现生鸟类中21目39种核c-mos基因和线粒体12S rRNA基因部分序列的分析,从分子角度对现生鸟类的早期进化及三趾鹑鸟类的系统发生进行了探讨.研究结果表明,鸡雁类是现生鸟类最古老的一个支系,现生鸟类的祖先并不是经白垩纪到第三纪大灭绝后残留下来的一些过渡性水鸟(transitional shorebirds).在现生鸟类中,今腭型鸟类为并系发生,古腭型鸟类为单系发生.三趾鹑类在系统发生中晚于鸡雁类和古腭型鸟类,早于今腭型鸟类中非鸡雁类鸟类与鹤形目鸟类的亲缘关系较远.建议将现生鸟类分为初鸟下纲和新鸟下纲2个下纲,三趾鹑类属新鸟下纲的三趾鹑目(Turniciformes).     

FROM FROND TO FAN: ARCHAEOPTERYX AND THE EVOLUTION OF SHORT-TAILED BIRDS

Modern birds have extremely short tail skeletons relative to Archaeopteryx and nonavialian theropod dinosaurs. Long- and short-tailed birds also differ in the conformation of main tail feathers making up the flight surface: frond shaped in Archaeopteryx and fan shaped in extant fliers. Mechanisms of tail fanning were evaluated by electromyography in freely flying pigeons and turkeys and by electrical stimulation of caudal muscles in anesthetized birds. Results from these experiments reveal that the pygostyle, rectrices, rectricial bulbs, and bulbi rectricium musculature form a specialized fanning mechanism. Contrary to previous models, our data support the interpretation that the bulbi rectricium independently controls tail fanning; other muscles are neither capable of nor necessary for significant rectricial abduction. This bulb mechanism permits rapid changes in tail span, thereby allowing the exploitation of a wide range of lift forces. Isolation of the bulbs on the pygostyle effectively decouples tail fanning from fan movement, which is governed by the remaining caudal muscles. The tail of Archaeopteryx, however, differs from this arrangement in several important respects. Archaeopteryx probably had a limited range of lift forces and tight coupling between vertebral and rectricial movement. This would have made the tail of this primitive flier better suited to stabilization than maneuverability. The capacity to significantly alter lift and manipulate the flight surface without distortion may have been two factors favoring tail shortening and pygostyle development during avian evolution.     

THE BIRDS OF TASMANIA: ECOLOGY AND EVOLUTION

SUMMARY Tasmania, about the size of Ireland, separated from the Australian mainland by 140 miles of sea, and isolated for about the last 12,000 years, has 104 species of native breeding land-birds, with the addition of ten introduced species. The environment is described; in particular the vegetation is classified into nine natural types and three produced by European man; and the distribution of the bird species among these is defined and discussed. The other vertebrates are briefly considered. No extinction is definitely known to have taken place as a result of European settlement except of the Tasmanian Emu (and of course Tasmanian Man). An attempt is made to reconstruct the Late Pleistocene history of Tasmania and its vegetation, with special reference to the Last Glaciation, when the island would have been joined to the mainland. When the avifauna is divided into categories, water-birds, raptors, etc., it is found to have much the same proportional composition as the Australian mainland avifaunas with which it is compared, though it consists of many fewer species. The vegetation types of the colder and wetter areas of Tasmania house far fewer species of birds than the drier and warmer habitats. The 104 breeding species include 14 endemics, which are considered in detail, and 27 endemic subspecies. As shown by comparison with other islands, the total proportionate endemism is extraordinarily high for a recent continental island (though it is actually lower than that in the remote ecological island formed by the sclerophyll of southwestern Western Australia). A contributory cause may be that Tasmania is not regularly visited by land-birds from the continent (though at least one-fifth of the Tasmanian species are partial or total migrants in winter). The most noteworthy endemics are two monotypic genera, Lathamus and Acanthornis, and the Native Hen Tribonyx mortierii, which has become flightless apparently in the face of a formidable array of local predators. Considerations of climate and habitat suggest that at least half the avifauna, including 19 of the endemic subspecies and six of the members of superspecies, arrived in Tasmania some time after the amelioration of the Last Glaciation began, some 18,000 years ago. Geographical considerations suggest that four of those six members of superspecies existed in their present form when the land-bridge to the mainland was cut, 12,000 years ago. Certain habitats, widespread over southeastern Australia during the glaciation, are now virtually confined to Tasmania where they form the stronghold of certain species, such as the Pink Robin Petroica rodinogaster, which occur only as relicts on the mainland. The endemic Scrub Tit Acanthornis magnus is practically confined to such habitats, where its ecology suggests it would have been well adapted to glacial conditions. Among the local endemics there is a strong tendency for colouration to be more saturated than on the continent of Australia (Gloger's rule) but there is less consistency in tendency to greater size (Bergmann's rule). A noteworthy proportion of the Tasmanian species have duller plumage than their mainland relatives, usually with an assimilation to female or juvenile plumage—unexpected in an island as big as Tasmania with so considerable an avifauna.