英语听力:自然百科 撒哈拉的史前鳄鱼化石
时间:2018-12-26 作者:英语课 分类:自然百科2009年
英语课
A National Geographic 1 researcher and his team have uncovered fossilized remains 2 of 5 ancient crocodile species that lived among dinosaurs 4 some 100 million years ago. One of the crocs had an oversized set of canines 5, and another had a snout like a duck's bill.
They were discovered in the North African Sahara, where National Geographic Explorer-in-Residence Paul Sereno began expeditions 15 years ago.
During those expeditions, Sereno first discovered an ancient croc, popularly known as Supercroc. At 40 feet long and ten tons, it was big enough to take down a dinosaur 3.
These stubby teeth didn't even touch each other to snare 6 a fish? No, they were hook-like, strong cylinders 7 to grab onto a dinosaurs limb or neck and pull it into the water. We've begun to understand this animal as a hidden predator 8 of the dinosaurs.
Sereno and his team soon discovered key fossils of previously 9 unknown or poorly understood species, most of them walking upright.
I began to realize that we really have half a dozen new species. And one of the great things we found in the Sahara was this world of crocodilians that we had no idea existed when we set foot there.
Sereno assembled a team of experts to re-create what these crocs might have looked like with computers and elastic 10 casts. One of the most beautifully preserved specimens 11, Sereno calls it
'little duck croc", is flat-billed with long-sleek leg bones and about 3-feet long.
What would a long-limbed crocodile be like? I mean, would it really be like a mammal? How would it have moved? How does this galloping 13 crocodile do it?
And another of the new species, the 20-foot, triple fanged 14 reptile 15 dubbed 16 Boar Croc, could gallop 12, too. It had a head and mouth that could bring down a dinosaur. In the National Geographic Special, When Crocs Ate Dinosaurs, Sereno travels to Australia to witness living crocodiles with similar traits to the now extinct fossilized ancestors he's found in Northern Africa.
The Australian galloping crocodile, known as the freshie, can sprint 17 on land at high speed, using the up and down motion of a true terrestrial animal. But in the water, goes back to the sidewinder motion of a tail-propelled river creature. It helps Sereno and his team visualize 18 how the ancient crocs, especially the boar croc, could have been a terror to the dinosaurs.
They would have pursued dinosaurs on land with agility 19. And then they would have turned around and dove into the water, and swam away like a freshie. That I really think is the secret to crocodile success.
The other ancient crocs discovered are: the Pancake Croc, 20 feet long with a thin, 3-foot long set of jaws 21; Dog Croc was about 3-feet long and had a very large forebrain, possibly indicating higher intelligence, and likely was as comfortable on land as in the water; and Rat Croc was about 3-feet long with a pair of buckteeth in the lower jaw 20 to flesh out small prey 22. When Crocs Ate Dinosaurs premieres November 21st, at 9pm Eastern on the National Geographic Channel.
1 geographic
adj.地理学的,地理的
- The city's success owes much to its geographic position. 这座城市的成功很大程度上归功于它的地理位置。 来自《简明英汉词典》
- Environmental problems pay no heed to these geographic lines. 环境问题并不理会这些地理界限。 来自英汉非文学 - 环境法 - 环境法
2 remains
n.剩余物,残留物;遗体,遗迹
- 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。
3 dinosaur
n.恐龙
- 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。
4 dinosaurs
n.恐龙( dinosaur的名词复数 );守旧落伍的人,过时落后的东西
- 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 canines
n.犬齿( canine的名词复数 );犬牙;犬科动物
- For example, the teeth are more primitive. There are large canines and unusually shaped incisors. 譬如,牙齿更为原始,有大的犬齿和非常合适的门齿。 来自辞典例句
- Well-to-canines can attend doggy daycare centers while their owners work. 富人家的狗在主人上班的时候可以去狗狗托管中心。 来自互联网
6 snare
n.陷阱,诱惑,圈套;(去除息肉或者肿瘤的)勒除器;响弦,小军鼓;vt.以陷阱捕获,诱惑
- I used to snare small birds such as sparrows.我曾常用罗网捕捉麻雀等小鸟。
- Most of the people realized that their scheme was simply a snare and a delusion.大多数人都认识到他们的诡计不过是一个骗人的圈套。
7 cylinders
n.圆筒( cylinder的名词复数 );圆柱;汽缸;(尤指用作容器的)圆筒状物
- They are working on all cylinders to get the job finished. 他们正在竭尽全力争取把这工作干完。 来自《简明英汉词典》
- That jeep has four cylinders. 那辆吉普车有4个汽缸。 来自《简明英汉词典》
8 predator
n.捕食其它动物的动物;捕食者
- The final part of this chapter was devoted to a brief summary of predator species.本章最后部分简要总结了食肉动物。
- Komodo dragon is the largest living lizard and a fearsome predator.科摩多龙是目前存在的最大蜥蜴,它是一种令人恐惧的捕食性动物。
9 previously
adv.以前,先前(地)
- 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。
10 elastic
n.橡皮圈,松紧带;adj.有弹性的;灵活的
- Rubber is an elastic material.橡胶是一种弹性材料。
- These regulations are elastic.这些规定是有弹性的。
11 specimens
n.样品( specimen的名词复数 );范例;(化验的)抽样;某种类型的人
- Astronauts have brought back specimens of rock from the moon. 宇航员从月球带回了岩石标本。
- The traveler brought back some specimens of the rocks from the mountains. 那位旅行者从山上带回了一些岩石标本。 来自《简明英汉词典》
12 gallop
v./n.(马或骑马等)飞奔;飞速发展
- They are coming at a gallop towards us.他们正朝着我们飞跑过来。
- The horse slowed to a walk after its long gallop.那匹马跑了一大阵后慢下来缓步而行。
13 galloping
adj.有尖牙的,有牙根的,有毒牙的
- The piercing wind fanged his ears. 刺骨的寒风吹得他耳朵疼痛。 来自《现代英汉综合大词典》
- The fanged dagger, with spikes protruding from the handle. 手柄有突出尖状物的有尖牙状的匕首。 来自互联网
14 reptile
n.爬行动物;两栖动物
- The frog is not a true reptile.青蛙并非真正的爬行动物。
- So you should not be surprised to see someone keep a reptile as a pet.所以,你不必惊奇有人养了一只爬行动物作为宠物。
15 dubbed
v.给…起绰号( dub的过去式和过去分词 );把…称为;配音;复制
- Mathematics was once dubbed the handmaiden of the sciences. 数学曾一度被视为各门科学的基础。
- Is the movie dubbed or does it have subtitles? 这部电影是配音的还是打字幕的? 来自《简明英汉词典》
16 sprint
n.短距离赛跑;vi. 奋力而跑,冲刺;vt.全速跑过
- He put on a sprint to catch the bus.他全速奔跑以赶上公共汽车。
- The runner seemed to be rallied for a final sprint.这名赛跑者似乎在振作精神作最后的冲刺。
17 visualize
vt.使看得见,使具体化,想象,设想
- I remember meeting the man before but I can't visualize him.我记得以前见过那个人,但他的样子我想不起来了。
- She couldn't visualize flying through space.她无法想像在太空中飞行的景象。
18 agility
n.敏捷,活泼
- The boy came upstairs with agility.那男孩敏捷地走上楼来。
- His intellect and mental agility have never been in doubt.他的才智和机敏从未受到怀疑。
19 jaw
n.颚,颌,说教,流言蜚语;v.喋喋不休,教训
- 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。