恐龙羽毛的颜色首次被鉴定-凯发k8官网

恐龙羽毛的颜色首次被鉴定
文章来源:未知 文章作者:meng 发布时间:2010-01-29 01:37 字体: [ ] 
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the colour of some feathers on 2 and early birds has been identified for the first time, reports a paper published in nature this week. the research found that the theropod兽脚亚目的 1 sinosauropteryx had simple bristles猪鬃4 of feathers – in alternate orange and white rings down its tail, and that the early bird confuciusornis had patches斑块,补丁 of white, black and orange-brown colouring. future work will allow precise mapping of colours and patterns across the whole bird.

mike benton, professor of palaeontology at the university of bristol, said, "our research provides extraordinary insights into the origin of feathers. in particular, it helps to resolve a long-standing debate about the original function of feathers – whether they were used for flight, 5绝缘,隔离, or display. we now know that feathers came before wings, so feathers did not originate as flight structures.

"we therefore suggest that feathers first arose as agents for colour display and only later in their 6 history did they become useful for flight and insulation."

the team of palaeontologists from the university of bristol, uk, the institute of vertebrate paleontology and paleoanthropology (ivpp) in beijing, university college dublin and the open university report two kinds of melanosomes黑色体 found in the feathers of numerous birds and dinosaurs from the world-famous jehol热河 beds of ne china.

melanosomes are colour-bearing organelles细胞器 buried within the structure of feathers and hair in modern birds and mammals, giving black, grey, and rufous红褐色的 tones such as orange and brown. because melanosomes are an integral part of the tough protein structure of the feather, they survive when a feather survives, even for hundreds of millions of years.

this is the first report of melanosomes found in the feathers of dinosaurs and early birds. it is also the first report of phaeomelanosomes in fossil feathers, the organelles that provide rufous and brown colours.

these discoveries confirm the substantial body of evidence that suggests birds evolved through a long line of theropod (flesh-eating) dinosaurs. it also demonstrates that the unique assemblage集合,聚集 of characters that make a modern bird – feathers, wings, lightweight skeleton, enhanced metabolic新陈代谢的 system, enlarged brain and visual systems – evolved step-by-step over some 50 million years of dinosaur evolution, through the jurassic and cretaceous periods.

"these discoveries open up a whole new area of research", said benton, "allowing us to explore aspects of the life and behaviour of dinosaurs and early birds that lived over 100 million years ago.

"furthermore, we now know that the simplest feathers in dinosaurs such as sinosauropteryx were only present over limited parts of its body – for example, as a crest到达绝顶 down the midline of the back and round the tail – and so they would have had only a limited function in thermoregulation温度调节.

"feathers are key to the success of birds and we can now 9仔细分析 their evolutionary history in detail and see how each feather type – and the fine detail of feather structure – was acquired through time. this will link with current work on how the genome controls feather development."



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1 xusxp     
n.恐龙
参考例句:
  • are you trying to tell me that david was attacked by a dinosaur?你是想要告诉我大卫被一支恐龙所攻击?
  • he stared at the faithful miniature of the dinosaur.他凝视著精确的恐龙缩小模型。
2 87f9c39b9e3f358174d58a584c2727b4     
n.恐龙( dinosaur的名词复数 );守旧落伍的人,过时落后的东西
参考例句:
  • the brontosaurus was one of the largest of all dinosaurs. 雷龙是所有恐龙中最大的一种。 来自《简明英汉词典》
  • dinosaurs have been extinct for millions of years. 恐龙绝种已有几百万年了。 来自《简明英汉词典》
3 d40df625d0ab9008a3936dbd866fa2ec     
短而硬的毛发,刷子毛( bristle的名词复数 )
参考例句:
  • the bristles on his chin 他下巴上的胡楂子
  • this job bristles with difficulties. 这项工作困难重重。
4 5e19fce64ab14f5a4b5c8687640c2593     
n.先驱( precursor的名词复数 );先行者;先兆;初期形式
参考例句:
  • phenyl (or polyphenyl) substituted epoxides serve as excellent precursors to phenyl (or diphenyl) carbenes. 某些苯代(或多苯)环氧乙烷是制取带苯环(或二苯)碳烯的极好原料。 来自辞典例句
  • note the presence of megakaryocytes, erythroid islands, and granulocytic precursors. 可见巨核细胞,红细胞岛和粒细胞前体细胞。 来自互联网
5 q5jxt     
n.隔离;绝缘;隔热
参考例句:
  • please examine the insulation of the electric wires in my house.请检查一下我屋子里电线的绝缘情况。
  • it is always difficult to assure good insulation between the electric leads.要保证两个电触头之间有良好的绝缘总是很困难的。
6 ctqz7m     
adj.进化的;演化的,演变的;[生]进化论的
参考例句:
  • life has its own evolutionary process.生命有其自身的进化过程。
  • these are fascinating questions to be resolved by the evolutionary studies of plants.这些十分吸引人的问题将在研究植物进化过程中得以解决。
7 2r4z1     
adj.新陈代谢的
参考例句:
  • impressive metabolic alternations have been undergone during embryogenesis.在胚胎发生期间经历了深刻的代谢变化。
  • a number of intoxicants are associated with metabolic acidosis.许多毒性物质可引起代谢性酸中毒。
8 raqya     
n.顶点;饰章;羽冠;vt.达到顶点;vi.形成浪尖
参考例句:
  • the rooster bristled his crest.公鸡竖起了鸡冠。
  • he reached the crest of the hill before dawn.他于黎明前到达山顶。
9 3tnxq     
v.分割;解剖
参考例句:
  • in biology class we had to dissect a frog.上生物课时我们得解剖青蛙。
  • not everyone can dissect and digest the public information they receive.不是每个人都可以解析和消化他们得到的公共信息的。
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