研究:古蛇以恐龙幼仔为食
文章来源:未知 文章作者:meng 发布时间:2010-03-03 00:16 字体: [ ]  进入论坛
(单词翻译:双击或拖选)

Sixty-seven million years ago, when dinosaur1 hatchlings(刚孵化的幼体) first scrambled2(攀登,争夺) out of their eggs, their first—and last—glimpse of the world might have been the open jaws4 of a 3.5-metre-long snake named Sanajeh indicus, based on the discovery in India of a nearly complete fossilized skeleton(骨架,骨骼) of a primitive5(原始的,远古的) snake coiled(盘绕,卷) inside a dinosaur nest. The snake lacked the wide-jawed gape6(裂口,张嘴) seen in modern snakes such as pythons(蟒蛇) and boas, which would have prohibited it from eating rigid7 dinosaur eggs. But baby dinosaurs8 would have been just the right prey9 size for a large snake, says Jason Head, a paleontologist(古生物学者) and assistant professor in the Department of Biology at the University of Toronto Mississauga.

"Living primitive snakes are small animals whose diet is limited by their jaw3 size, but the evolution of a large body size in Sanajeh would have allowed it to eat a wide range of prey, including dinosaur hatchlings," says Head. "This is the first direct evidence of feeding behavior in a fossil primitive snake, and shows us that the ecology(生态学) and early evolutionary10 history of snakes were much more complex than we would think just by looking at modern snakes today."

The fossils were first found in 1987 by dinosaur egg expert Dhananjay Mohabey from the Geological Survey of India, in rocks of the Lameta Formation in Gujarat, a state in western India known for its rich fossil record of dinosaurs and their eggs. Originally identified as a hatchling dinosaur, the fossils were recognized to include a snake by dinosaur paleontologist Jeff Wilson from the University of Michigan and Mohabey in 2001.

"I saw the characteristic vertebrae(椎骨,脊椎) of a snake beside the dinosaur eggshell and larger bones, and I knew it was an extraordinary specimen11 ... even if I couldn't put the whole story together at that point. I just knew we needed to examine it further," said Wilson. They invited snake specialist Head and geologist12 Shanan Peters from the University of Wisconsin-Madison, to collaborate13 on the study of the fossils, including field and lab work in India, the U.S.A., and Canada.

Sanajeh indicus, which means "ancient gape from India", is represented by a nearly complete skull14 and lower jaws along with vertebrae and ribs15 coiled around a crushed titanosaur egg, next to the remains16 of a 0.5-metre-long titanosaur(雷龙) hatchling. These dinosaurs, part of a larger group called sauropods(蜥脚类动物) , were long-necked, four-legged plant-eaters that grew to weigh up to 100 tonnes, and Wilson says they likely grew quickly in their first year, beyond the reach of predators17(食肉动物,捕食者) like Sanajeh.

The findings—along with two other similar snake-egg pairings, suggest that snakes fed on titanosaur hatchlings when they emerged from their eggs. "The eggs were laid in loose sands and covered by a thin layer of sediment18(沉淀物,沉淀) . We think that the hatchling had just exited its egg, and its movement attracted the snake," explains Mohabey. "It would have been a smorgasbord(瑞典式自助餐) ," says Head. "Hundreds or thousands of defenseless baby sauropods could have supported an ecosystem19 of predators during the hatching season."

The remains capture a moment in Cretaceous time. "Burial was rapid and deep," says Peters. "Probably a pulse of slushy(泥泞的,融雪的) sand and mud released during a storm caught them in the act(当场,正要) ."



点击收听单词发音收听单词发音  

1 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。
2 scrambled 2e4a1c533c25a82f8e80e696225a73f2     
v.快速爬行( scramble的过去式和过去分词 );攀登;争夺;(军事飞机)紧急起飞
参考例句:
  • Each scrambled for the football at the football ground. 足球场上你争我夺。 来自《现代汉英综合大词典》
  • He scrambled awkwardly to his feet. 他笨拙地爬起身来。 来自《简明英汉词典》
3 jaw 5xgy9     
n.颚,颌,说教,流言蜚语;v.喋喋不休,教训
参考例句:
  • He delivered a right hook to his opponent's jaw.他给了对方下巴一记右钩拳。
  • A strong square jaw is a sign of firm character.强健的方下巴是刚毅性格的标志。
4 jaws cq9zZq     
n.口部;嘴
参考例句:
  • The antelope could not escape the crocodile's gaping jaws. 那只羚羊无法从鱷鱼张开的大口中逃脱。
  • The scored jaws of a vise help it bite the work. 台钳上有刻痕的虎钳牙帮助它紧咬住工件。
5 primitive vSwz0     
adj.原始的;简单的;n.原(始)人,原始事物
参考例句:
  • It is a primitive instinct to flee a place of danger.逃离危险的地方是一种原始本能。
  • His book describes the march of the civilization of a primitive society.他的著作描述了一个原始社会的开化过程。
6 gape ZhBxL     
v.张口,打呵欠,目瞪口呆地凝视
参考例句:
  • His secretary stopped taking notes to gape at me.他的秘书停止了记录,目瞪口呆地望着我。
  • He was not the type to wander round gaping at everything like a tourist.他不是那种像个游客似的四处闲逛、对什么都好奇张望的人。
7 rigid jDPyf     
adj.严格的,死板的;刚硬的,僵硬的
参考例句:
  • She became as rigid as adamant.她变得如顽石般的固执。
  • The examination was so rigid that nearly all aspirants were ruled out.考试很严,几乎所有的考生都被淘汰了。
8 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》
9 prey g1czH     
n.被掠食者,牺牲者,掠食;v.捕食,掠夺,折磨
参考例句:
  • Stronger animals prey on weaker ones.弱肉强食。
  • The lion was hunting for its prey.狮子在寻找猎物。
10 evolutionary 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。
11 specimen Xvtwm     
n.样本,标本
参考例句:
  • You'll need tweezers to hold up the specimen.你要用镊子来夹这标本。
  • This specimen is richly variegated in colour.这件标本上有很多颜色。
12 geologist ygIx7     
n.地质学家
参考例句:
  • The geologist found many uncovered fossils in the valley.在那山谷里,地质学家发现了许多裸露的化石。
  • He was a geologist,rated by his cronies as the best in the business.他是一位地质学家,被他的老朋友们看做是这门行当中最好的一位。
13 collaborate SWgyC     
vi.协作,合作;协调
参考例句:
  • The work gets done more quickly when we collaborate.我们一旦合作,工作做起来就更快了。
  • I would ask you to collaborate with us in this work.我们愿意请你们在这项工作中和我们合作。
14 skull CETyO     
n.头骨;颅骨
参考例句:
  • The skull bones fuse between the ages of fifteen and twenty-five.头骨在15至25岁之间长合。
  • He fell out of the window and cracked his skull.他从窗子摔了出去,跌裂了颅骨。
15 ribs 24fc137444401001077773555802b280     
n.肋骨( rib的名词复数 );(船或屋顶等的)肋拱;肋骨状的东西;(织物的)凸条花纹
参考例句:
  • He suffered cracked ribs and bruising. 他断了肋骨还有挫伤。
  • Make a small incision below the ribs. 在肋骨下方切开一个小口。
16 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。
17 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》
18 sediment IsByK     
n.沉淀,沉渣,沉积(物)
参考例句:
  • The sediment settled and the water was clear.杂质沉淀后,水变清了。
  • Sediment begins to choke the channel's opening.沉积物开始淤塞河道口。
19 ecosystem Wq4xz     
n.生态系统
参考例句:
  • This destroyed the ecosystem of the island.这样破坏了岛上的生态系统。
  • We all have an interest in maintaining the integrity of the ecosystem.维持生态系统的完整是我们共同的利益。
发表评论
请自觉遵守互联网相关的政策法规,严禁发布色情、暴力、反动的言论。
评价:
表情:
验证码:点击我更换图片