共查询到20条相似文献，搜索用时 15 毫秒
1.
Jones TD Ruben JA Martin LD Kurochkin EN Feduccia A Maderson PF Hillenius WJ Geist NR Alifanov V 《Science (New York, N.Y.)》2000,288(5474):2202-2205
Longisquama insignis was an unusual archosaur from the Late Triassic of central Asia. Along its dorsal axis Longisquama bore a series of paired integumentary appendages that resembled avian feathers in many details, especially in the anatomy of the basal region. The latter is sufficiently similar to the calamus of modern feathers that each probably represents the culmination of virtually identical morphogenetic processes. The exact relationship of Longisquama to birds is uncertain. Nevertheless, we interpret Longisquama's elongate integumentary appendages as nonavian feathers and suggest that they are probably homologous with avian feathers. If so, they antedate the feathers of Archaeopteryx, the first known bird from the Late Jurassic. 相似文献
2.
猛禽非损伤性取样的性别分子鉴定方法 总被引：1，自引：0，他引：1
利用性染色体上CHD基因的P2/P8和2550F/2718R两对引物及微卫星位点(NVHfp102),对多种猛禽通过非损伤性取样进行性别分子鉴定研究。结果显示:2550F/2718R引物适用于隼形目脱落的有羽根羽毛和无羽根的不完整羽毛,拔取标本的羽毛可以进行鉴定尝试,适用于鸮形目脱落的有羽根羽毛,脱落的无羽根不完整羽毛和拔取标本的羽毛不必进行鉴定尝试;利用P2/P8引物进行非变性聚丙烯酰胺凝胶电泳性别鉴定适用于猛禽脱落的无羽根不完整羽毛和拔取的标本羽毛;微卫星位点(NVHfp102)适用于隼科鸟类各种样本。 相似文献
3.
Clarke JA Ksepka DT Salas-Gismondi R Altamirano AJ Shawkey MD D'Alba L Vinther J DeVries TJ Baby P 《Science (New York, N.Y.)》2010,330(6006):954-957
Penguin feathers are highly modified in form and function, but there have been no fossils to inform their evolution. A giant penguin with feathers was recovered from the late Eocene (~36 million years ago) of Peru. The fossil reveals that key feathering features, including undifferentiated primary wing feathers and broad body contour feather shafts, evolved early in the penguin lineage. Analyses of fossilized color-imparting melanosomes reveal that their dimensions were similar to those of non-penguin avian taxa and that the feathering may have been predominantly gray and reddish-brown. In contrast, the dark black-brown color of extant penguin feathers is generated by large, ellipsoidal melanosomes previously unknown for birds. The nanostructure of penguin feathers was thus modified after earlier macrostructural modifications of feather shape linked to aquatic flight. 相似文献
4.
本文研究５种禽类羽毛氨基酸组分和含量分析的差异．新浦东鸡的副羽含量最高达９０．１％；居古拉火鸡最低在７１％。１４种羽毛的氨基酸平均含量为８０％。从氨基酸组分看，丝氨酸，谷氨酸和亮氨酸较高。而赖氨酸，组氨酸和甲硫氨酸均较低，这与已发表的文献一致［３］。 相似文献
5.
利用京白Ⅱ系公鸡与罗斯褐商品代母鸡进行杂交,初生雏具有快、慢羽两种性状,通过观察分析、解剖证实:杂交后代能利用快、慢羽这一相对性状进行雌雄鉴别,效果可靠。从初生雏的毛色来看有五种不同类型,但以纯白色所占的比例最大,这证明京白Ⅱ系的白羽对罗斯鸡的褐羽为不完全显性。 相似文献
6.
Some nonavian theropod dinosaurs were at least partially covered in feathers or filamentous protofeathers. However, a complete understanding of feather distribution among theropod dinosaurs is limited because feathers are typically preserved only in lagerst?tten like that of Solnhofen, Germany or Liaoning, China. Such deposits possess clear taphonomic biases toward small-bodied animals, limiting our knowledge regarding feather presence in larger members of feathered clades. We present direct evidence of feathers in Velociraptor mongoliensis based on the presence of quill knobs on the posterior forearm. This report of secondaries in a larger-bodied, derived, and clearly flightless member of a nonavian theropod clade represented by feathered relatives is a substantial contribution to our knowledge of the evolution of feathers. 相似文献
7.
Paul GS 《Science (New York, N.Y.)》2010,330(6002):320; author reply 320
Nudds and Dyke (Reports, 14 May 2010, p. 887) compared the rachis diameters of the primary feathers of Archaeopteryx and Confuciusornis to those of modern birds and found that the primary feathers of these two basal birds were too weak to support sustained flight. Our measurements of Confuciusornis specimens suggest that their conclusions need to be further evaluated. 相似文献
8.
During courtship flights, males of some hummingbird species produce diverse sounds with tail feathers of varying shapes. We show that these sounds are produced by air flowing past a feather, causing it to aeroelastically flutter and generate flutter-induced sound. Scanning laser doppler vibrometery and high-speed video of individual feathers of different sizes and shapes in a wind tunnel revealed multiple vibratory modes that produce a range of acoustic frequencies and harmonic structures. Neighboring feathers can be aerodynamically coupled and flutter either at the same frequency, resulting in sympathetic vibrations that increase loudness, or at different frequencies, resulting in audible interaction frequencies. Aeroelastic flutter is intrinsic to stiff airfoils such as feathers and thus explains tonal sounds that are common in bird flight. 相似文献
9.
朱鹮羽毛的扫描电镜观察 总被引：5，自引：0，他引：5
用扫描电子显微镜对朱鹮(Nipponia nippon)不同部位羽毛进行了超微结构观察。结果表明:起飞翔作用的飞羽和尾羽主要由有钩羽小枝和无钩羽小枝构成;有钩羽小枝和无钩羽小枝相互啮合形成坚实的羽面来减少飞行阻力。组成羽冠的颈羽有着特殊的特点,先端羽小枝两侧全部为无钩羽小枝,而后沿着羽轴向根部逐渐变化,出现有钩羽小枝。尾羽的有钩羽小枝中的小钩数绝大多数为4个,纤毛为6对;飞羽的有钩羽小枝中的小钩数绝大多数为5个,少部分为6个,纤毛为6对;颈羽的有钩羽小枝小钩数绝大多数为4个,纤毛为5对。朱鹮的各羽小枝的腹齿数变化较大。羽轴及羽枝轴无明显特征,髓质层由多孔的髓腔构成。 相似文献
10.
为了确定饲喂鹅绒助长剂的鹅适宜首次拔毛时间和上下次拔毛时间间隔,利用对照组与试验组鹅各10只,分别从70日龄和第1次拔毛后的第36 d 开始,直至80日龄和首次拔毛后的第40 d,每隔1 d 观测各鹅颈下1/3、胸腹部和背部的血管毛根数和羽根血肉附着情况.结果表明,观测至80日龄和首次拔毛后第40 d 时,所测处,试验组无可见血管毛和血肉附着的羽根,而对照组却两者均存在.因此,饲喂鹅绒助长剂,进行养鹅拔毛时,适宜的首次拔毛时间是第80日龄,上下次拔毛的时间间隔为40 d. 相似文献
11.
Qin Wen-chao Chen Zhi-hui Chen Ying-lin Ma Cheng-zhan Sun Hao Lian Li-na Zhao Ze-yu Zhao Cheng Sun Jia-you Bai Yang Xu Liang-mei 《东北农业大学学报(英文版)》2021,28(4):56-67
The purpose of this experiment was to isolate and screen the microorganisms from the soil where chicken feathers were piled for a long time and identify them bi... 相似文献
12.
A primitive enantiornithine bird and the origin of feathers 总被引：2，自引：0，他引：2
A fossil enantiornithine bird, Protopteryx fengningensis gen. et sp. nov., was collected from the Early Cretaceous Yixian Formation of Northern China. It provides fossil evidence of a triosseal canal in early birds. The manus and the alular digit are long, as in Archaeopteryx and Confuciusornis, but are relatively short in other enantiornithines. The alula or bastard wing is attached to an unreduced alular digit. The two central tail feathers are scalelike without branching. This type of feather may suggest that modern feathers evolved through the following stages: (i) elongated scale, (ii) central shaft, (iii) barbs, and finally (iv) barbules and barbicel. 相似文献
13.
Vanes in the primary flight feathers of Archaeopteryx conform to the asymmetric pattern in modern flying birds. The asymmetry has aerodynamic functions and can be assumed to have evolved in the selective context of flight. 相似文献
14.
以雏鸡生产羽毛的羽髓组织，心脏，肝脏，肾脏为材料，进行了乳酸脱氢酶（ＬＤＨ）同工酶的垂直板凝胶电泳分析，结果表明，利用长期的羽毛羽髓组织，完全可以替代内脏组织因液采样进行同工酶测定，这将为珍禽和濒危鸟类的遗传分析奠定基础。 相似文献
15.
Identifying ornithophilous plant species utilized by several different flower-visiting birds is simplified by the scanning electron microscope. The technique involves comparing pollen samples taken from the birds' head feathers with pollen reference standards collected in the same area, which simplifies analysis of pollination patterns in a complex community. 相似文献
16.
The pigment on the secondary feathers of the cedar waxwing (Bombycilla cedrorum) is deposited as an amorphous layer upon a supporting medullary structure. The pigment was extracted with alkali and analyzed by chromatographic and spectrophotometric methods. The results indicate that the pigment is astacene (3,3',4,4'-tetra-keto-beta-carotene), the oxidation product of astaxanthin. 相似文献
17.
从南海海气相互作用的角度出发,综述了南海大气和海洋系统的平均特征及其变化特性,同时对南海海气相互作用的特点进行了概述。文章还就尚未解决的科学问题进行探讨,以引起有关学者的关注。 相似文献
18.
SUPPLEE WC 《Science (New York, N.Y.)》1963,139(3550):119-120
The growth of chicks decreased, and specific abnormalities of hocks and feathers increased, when cadmium was added to a zinc-deficient diet. Supplementation of the diet with zinc prevented the adverse effect of cadmium on hock and feather development and partially offset the effect on growth. Changes in the gizzard lining, also resulting from cadmium ingestion, were partially prevented by increase in the zinc intake. 相似文献
19.
[目的]研究麒麟鸡羽毛生长变化特点以及测定1~12周龄麒麟鸡的生长性能。[方法]对胚胎期8日龄至7周龄麒麟鸡的羽毛生长发育过程进行分析,并对1~12周龄麒麟鸡生长性能进行研究。[结果]麒麟鸡羽毛主要有黄、白和麻3种颜色,在胚胎期12日龄开始出现绒毛,出壳后第1周龄出现羽毛翻卷现象,第7周龄完成全身羽毛的翻卷;麒麟鸡公鸡生长速度比母鸡快,1日龄公、母鸡体重相近,分别为37.02 g和34.28 g,差异不显著(P0.05),而12周龄公、母鸡体重分别为1 598.01 g和1 324.57 g,存在显著差异(P0.05)。[结论]麒麟鸡羽毛翻卷独具特色,其生长速度快,生长性能高,能够为其作为特色优质肉鸡的开发利用提供理论依据。 相似文献