中国科学家发现1亿年前未知物种的羽毛
文章来源:未知 文章作者:enread 发布时间:2018-12-17 08:08 字体: [ ]  进入论坛
(单词翻译:双击或拖选)
Chinese scientists have discovered strange-shaped tail feathers in 100 million-year-old ambers which do not belong to any existing or known birds.
 
中国科学家在一些有1亿年历史的琥珀中发现奇怪形状的尾羽,这种尾羽不属于任何现存或已知的鸟类。
 
 
A cross-section of the central shaft1 of the tail feathers is shaped like the letter C, while all existing birds possess feathers with hollow tubes at the center in the shape of the letter O.
 
The C-shaped streamers were not as good for flying as O-shaped ones.
 
They were also very thin, less than the size of the average cell, and therefore less sturdy.
 
They were lighter2 than O-shape feathers and energy-efficient to produce, according to Xing Lida, head of the research team and associate professor at the China University of Geosciences.
 
Some of the feathers had dark brown strips and colorless strips appear alternately.
 
Since no scratches were found on the feathers and none of the bird's body parts were discovered near the feathers, scientists believe the light and colorful feathers easily fell when the bird faced predators3, Xing told the Global Times on Sunday.
 
Today's male birds use beautiful tail feathers to attract females in courtship. These once colorful feathers may have had a similar use.
 
The report said the feathers could have belonged to birds transitioning from dinosaurs4 as they were preserved in ambers formed in today's North Myanmar about 100 million years ago.
 
Most of the previously5 discovered tail streamers were flattened6 by stones, making the feathers nearly impossible to study.
 
"This discovery pointed7 out a new direction for us to explore evolution of ancient birds. Scientists used to take the modern O-shape streamers for granted when examining flattened feathers," Xing said.
 
The 31 examined ambers contain feathers as long as 5 centimeters, suggesting the birds would be at least 10 centimeters long.


点击收听单词发音收听单词发音  

1 shaft YEtzp     
n.(工具的)柄,杆状物
参考例句:
  • He was wounded by a shaft.他被箭击中受伤。
  • This is the shaft of a steam engine.这是一个蒸汽机主轴。
2 lighter 5pPzPR     
n.打火机,点火器;驳船;v.用驳船运送;light的比较级
参考例句:
  • The portrait was touched up so as to make it lighter.这张画经过润色,色调明朗了一些。
  • The lighter works off the car battery.引燃器利用汽车蓄电池打火。
3 predators 48b965855934a5395e409c1112d94f63     
n.食肉动物( predator的名词复数 );奴役他人者(尤指在财务或性关系方面)
参考例句:
  • birds and their earthbound predators 鸟和地面上捕食它们的动物
  • The eyes of predators are highly sensitive to the slightest movement. 捕食性动物的眼睛能感觉到最细小的动静。 来自《简明英汉词典》
4 dinosaurs 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》
5 previously bkzzzC     
adv.以前,先前(地)
参考例句:
  • The bicycle tyre blew out at a previously damaged point.自行车胎在以前损坏过的地方又爆开了。
  • Let me digress for a moment and explain what had happened previously.让我岔开一会儿,解释原先发生了什么。
6 flattened 1d5d9fedd9ab44a19d9f30a0b81f79a8     
[医](水)平扁的,弄平的
参考例句:
  • She flattened her nose and lips against the window. 她把鼻子和嘴唇紧贴着窗户。
  • I flattened myself against the wall to let them pass. 我身体紧靠着墙让他们通过。
7 pointed Il8zB4     
adj.尖的,直截了当的
参考例句:
  • He gave me a very sharp pointed pencil.他给我一支削得非常尖的铅笔。
  • She wished to show Mrs.John Dashwood by this pointed invitation to her brother.她想通过对达茨伍德夫人提出直截了当的邀请向她的哥哥表示出来。
TAG标签: tail birds feathers
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