霸王龙如何成为白垩纪的霸主
文章来源:未知 文章作者:enread 发布时间:2016-03-15 05:22 字体: [ ]  进入论坛
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The fossilized remains1 of a new horse-sized dinosaur2 reveal how Tyrannosaurus rex and its close relatives became top predators3, according to a new study published in the Proceedings4 of the National Academy of Sciences. Paleontologists have long known from the fossil record that the family of dinosaurs5 at the center of the study--tyrannosaurs--transitioned from small-bodied species to fearsome giants like the T. rex over the course of 70 million years. But now, newly discovered dinosaur fossils suggest that much of this transition and growth in size occurred suddenly, toward the end of this 70 million-year period. The study also shows that before the evolution of their massive size, tyrannosaurs had developed keen senses and cognitive6 abilities, including the ability to hear low-frequency sounds. This positioned them to take advantage of opportunities to reach the top of their food chain in the Late Cretaceous Period after other groups of large meat-eating dinosaurs had gone extinct about 80-90 million years ago.
 
Until now, little was known about how tyrannosaurs became the giant, intelligent predators that dominated the landscape about 70 to 80 million years ago. The newly discovered species, named Timurlengia euotica, lived about 90 million years ago and fills a 20 million-year gap in the fossil record of tyrannosaurs. The new species is a tyrannosaur but not the ancestor of the T. rex.
 
"Timurlengia was a nimble pursuit hunter with slender, blade-like teeth suitable for slicing through meat," said Hans Sues, chair of the Department of Paleobiology at the Smithsonian's National Museum of Natural History. "It probably preyed7 on the various large plant-eaters, especially early duck-billed dinosaurs, which shared its world. Clues from the life of Timurlengia allow us to fill in gaps and better understand the life and evolution of other related dinosaurs, like T. rex."
 
Sues and Alexander Averianov, a senior scientist at the Russian Academy of Sciences, collected the fossils at the center of the study between 1997 and 2006 while co-leading international expeditions to the Kyzylkum Desert of Uzbekistan.
 
"Central Asia was the place where many of the familiar groups of Cretaceous dinosaurs had their roots," Sues said. "The discoveries from the Kyzylkum Desert of Uzbekistan are now helping8 us to trace the early history of these animals, many of which later flourished in our own backyard in North America."


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1 remains 1kMzTy     
n.剩余物,残留物;遗体,遗迹
参考例句:
  • He ate the remains of food hungrily.他狼吞虎咽地吃剩余的食物。
  • The remains of the meal were fed to the dog.残羹剩饭喂狗了。
2 dinosaur 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。
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 proceedings Wk2zvX     
n.进程,过程,议程;诉讼(程序);公报
参考例句:
  • He was released on bail pending committal proceedings. 他交保获释正在候审。
  • to initiate legal proceedings against sb 对某人提起诉讼
5 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》
6 cognitive Uqwz0     
adj.认知的,认识的,有感知的
参考例句:
  • As children grow older,their cognitive processes become sharper.孩子们越长越大,他们的认知过程变得更为敏锐。
  • The cognitive psychologist is like the tinker who wants to know how a clock works.认知心理学者倒很像一个需要通晓钟表如何运转的钟表修理匠。
7 preyed 30b08738b4df0c75cb8e123ab0b15c0f     
v.掠食( prey的过去式和过去分词 );掠食;折磨;(人)靠欺诈为生
参考例句:
  • Remorse preyed upon his mind. 悔恨使他内心痛苦。 来自《现代英汉综合大词典》
  • He had been unwise and it preyed on his conscience. 他做得不太明智,这一直让他良心不安。 来自辞典例句
8 helping 2rGzDc     
n.食物的一份&adj.帮助人的,辅助的
参考例句:
  • The poor children regularly pony up for a second helping of my hamburger. 那些可怜的孩子们总是要求我把我的汉堡包再给他们一份。
  • By doing this, they may at times be helping to restore competition. 这样一来, 他在某些时候,有助于竞争的加强。
TAG标签: fossil dinosaurs T. rex
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