VOA慢速英语2014 Scientists Identify Remains of Bird-Like Dinosaur in North America 科学家北美发现似鸟恐龙的遗迹

 

Scientists Identify Remains¹ of Bird-Like Dinosaur² in North America 科学家北美发现似鸟恐龙的遗迹

From VOA Learning English, this is Science in the News. 

I’m Anna Matteo.

And I’m Christopher Cruise. 

Today on the program, we tell about some of the many recent discoveries about dinosaurs³. These creatures died out long ago, but scientists are still learning lots of things about them. 

The “Chicken from Hell”

Dinosaur experts have identified the remains of an ancient, bird-like creature formerly⁴ unknown to scientists. The animal lived in what is now North America almost 70 million years ago. It was large and covered with feathers. Experts say the dinosaur belongs to a group of plant- and meat-eating creatures that once lived in Central and East Asia.

Scientists say the animal looked like a mix between a very large chicken and a big reptile⁵ or lizard⁶. In the words of one researcher, it looked like a “stretched-out chicken.”

Scientists are calling the dinosaur “Anzu wyliei.” They say it had a beak⁷, or hard nose, but no teeth for breaking down food. It had a long neck, a bony crest⁸ on the top of its head and very sharp claws.

Hans-Dieter Sues is a paleontologist with the Smithsonian Institution’s National Museum of Natural History in Washington, DC.

“So you basically have this, this great big, bird-like creature with a long tail, long arms ending in huge claws, feathers over all of its body.” 

The dinosaur was identified from three sets of fossil remains. The fossils were discovered in a place called the “Upper Cretaceous Hell Creek⁹ Formation.” It is in the American states of North and South Dakota. So, paleontologists are calling the creature the “Chicken from Hell.” They say it was more than three-and-a-half meters tall and weighed between 200 and 300 kilograms.

There is an almost-complete skeleton of Anzu Wylei at the Carnegie Museum of Natural History in Pittsburgh, Pennsylvania. Researchers with the Smithsonian discovered one of the fossils. They helped describe the findings in a report in the journal PLoS One.

Hans-Dieter Sues says the large, feathered animal belongs to a family of dinosaurs called “Oviraptorosauria.” He says Anzu is named for a mythological¹⁰ bird-like creature from Mesopotamia. It ate both plants and animals, and lived in wetlands.

Anzu was one of the last dinosaurs to live in what is now the United States. Mr. Sues says it lived in the same area -- and around the same time -- as the horned triceratops and Tyrannosaurus Rex. But Anzu had long, powerful legs and sharp edges on its wings. As a result, it was not easy to kill.

“Anyone who has ever sort of tried to corner an ostrich¹¹ today has lived to regret this because these animals are certainly, when, when they are cornered, they will certainly defend themselves very effectively, and particularly this animal with its huge hand claws would certainly (have) shredded¹² any attacker.”

The dinosaur family to which Anzu and its Asian relatives belong also includes creatures as small as another modern bird, the turkey. 

Scientists have suspected for almost a century that giant oviraptosaurs once lived in what is now North America. The latest fossil evidence proves that their theories were correct. Hans-Dieter Sues says there may be bones in other collections that will help paleontologists get a better understanding of “The Chicken From Hell.” 

Found: A Tiny T-Rex

Paleontologists recently found the fossilized remains of a very small Tyrannosaurus Rex in northern Alaska. They say the creature lived in the Arctic about 70 million years ago. It was half the size of its relatives living farther to the south.

Most cars weigh more than the small T. Rex did. Researchers have named it “Nanuqsaurus.” The name means “polar bear lizard” in the Alaskan Inupiat language. Its scientific name is Nanuqsaurus hoglundi.

Scientists say when the dinosaur was fully-grown, it was about six meters long and weighed just 450 kilograms. They say the creature looked just like its huge relative, except that it was just half the size.

The paleontologists work for the Perot Museum in Dallas, Texas. They reported finding part of a skull¹³ and upper and lower jaw¹⁴ bones of the small T. Rex. They made the discovery while digging up the remains of another small, horned creature formerly unknown to scientists. 

Anthony Fiorillo found the bones of Nanuqsaurus in the Prince Creek Formation in Alaska’s North Slope.

“I am absolutely thrilled by this discovery. And the fact that we found not one, but two brand-new animals in the very same hole in the ground is absolutely mind-boggling to me.”

The discovery of Nanuqsaurus did not come as a complete surprise to the researchers. They had suspected the existence of a meat-eating predator¹⁵ in the Arctic. That is because they had found teeth marks on the bones of the horned dinosaur. They say it was probably a victim of the small T. Rex.

Matt Lamanna is with the Carnegie Museum of Natural History in Pittsburgh. He says because the Arctic is dark for half of the year, there was probably not much for the Nanuqsaurus to eat.

“There was evolutionary¹⁶ pressure on it to develop small size because the environment it was living in probably would have had less food -- or at least less consistently-available food -- than environments further south that were, you know, far less seasonal¹⁷ that didn’t have long periods of darkness and long periods of light.”

Experts say Nanuqsaurus was not the only ancient creature that learned how to survive in extreme environments. Some mammoths the size of cows once lived on an island along Russia’s Arctic coast.

Anthony Fiorillo and his team describe their discovery of the small Tyrannosaur in the journal PLoS One.

Losing Teeth: The Daily Life of Dinosaurs

Plant-eating dinosaurs that lived between 76 and 150 million years ago are the subject of two recent studies. One study examined a newly-discovered species, or class, of dinosaur. The other looked closely at the teeth of these ancient creatures.

Grand Staircase Escalante National Monument is considered the last great, largely unexplored area for dinosaur fossils in the United States. You can find it in the high desert of southern Utah. 

In recent years, paleontologists working there have found evidence of about 20 species. Their latest discovery is called “Nasutoceratops,” which means “big-nosed, horn face.” It appears to be a new member of the horned dinosaur family related to the Triceratops.

Sampson led the project as chief curator of the Natural History Museum at the University of Utah. He says Nasutoceratops lived 76 million years ago.    

“He, and/or she is unique in having this tiny little horn over the nose and then these big long horns over the eyes, which is very different from the closest relative within that group of horned dinosaurs.”    

The four-legged, plant-eating creature was five meters long from head to tail and weighed about 2.5 tons. Scott Sampson says the discovery includes a nearly complete 1.5 meter-long skull, and pieces of two or three other skulls¹⁸.  

“With that mostly-complete skull there is a neck and part of the back that is the vertebrae in the backbone¹⁹. We also have a forelimb shoulder and forelimb all the way down to the foot on that one animal. So, we’re missing the back end of Nasutoceratops right now.”

Nasutoceratops will be on permanent display at the Natural History Museum of Utah. The discovery was reported last year in the British scientific journal Proceedings²⁰ of the Royal Society B.

Dinosaurs’ Teeth Tell the Story of Their Daily Life

Another scientific journal -- PLoS One -- recently told about one of the largest plant-eaters ever discovered: the long-necked, long-tail, large-bodied sauropod. Michael D’Emic is a paleontologist at Stony²¹ Brook²² University in New York State. He and other researchers studied two distantly-related dinosaurs -- Diplodocus and Camarasaurus. They are each large in size, but have different body types.  

Diplodocus has low shoulders and a whip-like tail. It also has a very long neck and a skull shaped like that of a horse. Camarasaurus had a shorter neck and thicker tail, larger teeth and a wider skull.

“Our starting question was: ‘How did these animals live for so long, side-by-side in the same ecosystem²³?’” 

Michael D’Emic believed that what the animals ate may have helped them live together. So he and other researchers removed teeth from the skulls of two of the animals to search for clues.  

“We looked at their tooth shapes, their tooth sizes, and their tooth formation and replacement²⁴ rates and we found that those things were very different in these two animals.”

About 150 million years ago, Diplodocus and Camarasaurus ate plants like ferns and hard-to-chew evergreen²⁵ vegetation like conifers. These cones²⁶ could quickly wear down the dinosaurs’ teeth. But sauropod teeth grew quickly: when one tooth fell out, another was ready to replace it.

Michael D’Emic says the study showed how quickly that happened.

“Diplodocus was an extreme case. So, it would have had a new tooth in each tooth socket²⁷ about every month. Camarasaurus, a little bit slower -- about one tooth every two months. Now because Camarasaurus’ teeth are so much bigger and broader though than were Diplodocus’ were, it was actually producing and going through a lot more material faster.”

He says eating customs helped the two large dinosaurs survive in the same ecosystem. He says Camarasaurus was careful about what it ate. But Diplodocus put its head to the ground and eat as much as it could as fast as it could. 

He says studies like his tell us about the daily life of dinosaurs.

 

This Science in the News was based on stories from VOA reporters Jessica Berman and Rosanne Skirble. It was written and produced by Christopher Cruise. 

1 remains   

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   

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 dinosaurs   

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》

4 formerly   

adv.从前，以前

参考例句：

• We now enjoy these comforts of which formerly we had only heard.我们现在享受到了过去只是听说过的那些舒适条件。
• This boat was formerly used on the rivers of China.这船从前航行在中国内河里。

5 reptile   

n.爬行动物；两栖动物

参考例句：

• 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。

6 lizard   

n.蜥蜴，壁虎

参考例句：

• A chameleon is a kind of lizard.变色龙是一种蜥蜴。
• The lizard darted out its tongue at the insect.蜥蜴伸出舌头去吃小昆虫。

7 beak   

n.鸟嘴，茶壶嘴，钩形鼻

参考例句：

• The bird had a worm in its beak.鸟儿嘴里叼着一条虫。
• This bird employs its beak as a weapon.这种鸟用嘴作武器。

8 crest   

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 creek   

n.小溪，小河，小湾

参考例句：

• He sprang through the creek.他跳过小河。
• People sunbathe in the nude on the rocks above the creek.人们在露出小溪的岩石上裸体晒日光浴。

10 mythological   

adj.神话的

参考例句：

• He is remembered for his historical and mythological works. 他以其带有历史感和神话色彩的作品而著称。
• But even so, the cumulative process had for most Americans a deep, almost mythological significance. 不过即使如此，移民渐增的过程，对于大部分美国人，还是意味深长的，几乎有不可思议的影响。

11 ostrich   

n.鸵鸟

参考例句：

• Ostrich is the fastest animal on two legs.驼鸟是双腿跑得最快的动物。
• The ostrich indeed inhabits continents.鸵鸟确实是生活在大陆上的。

12 shredded   

shred的过去式和过去分词

参考例句：

• Serve the fish on a bed of shredded lettuce. 先铺一层碎生菜叶，再把鱼放上，就可以上桌了。
• I think Mapo beancurd and shredded meat in chilli sauce are quite special. 我觉得麻婆豆腐和鱼香肉丝味道不错。 来自《简明英汉词典》

13 skull   

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。

14 jaw   

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。

15 predator   

n.捕食其它动物的动物；捕食者

参考例句：

• 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。

16 evolutionary   

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。

17 seasonal   

adj.季节的，季节性的

参考例句：

• The town relies on the seasonal tourist industry for jobs.这个城镇依靠季节性旅游业提供就业机会。
• The hors d'oeuvre is seasonal vegetables.餐前小吃是应时蔬菜。

18 skulls   

颅骨( skull的名词复数 )； 脑袋； 脑子； 脑瓜

参考例句：

• One of the women's skulls found exceeds in capacity that of the average man of today. 现已发现的女性颅骨中，其中有一个的脑容量超过了今天的普通男子。
• We could make a whole plain white with skulls in the moonlight! 我们便能令月光下的平原变白，遍布白色的骷髅！

19 backbone   

n.脊骨，脊柱，骨干；刚毅，骨气

参考例句：

• The Chinese people have backbone.中国人民有骨气。
• The backbone is an articulate structure.脊椎骨是一种关节相连的结构。

20 proceedings   

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

21 stony   

adj.石头的，多石头的，冷酷的，无情的

参考例句：

• The ground is too dry and stony.这块地太干，而且布满了石头。
• He listened to her story with a stony expression.他带着冷漠的表情听她讲经历。

22 brook   

n.小河，溪；v.忍受，容让

参考例句：

• In our room we could hear the murmur of a distant brook.在我们房间能听到远处小溪汩汩的流水声。
• The brook trickled through the valley.小溪涓涓流过峡谷。

23 ecosystem   

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。

24 replacement   

n.取代，替换，交换；替代品，代用品

参考例句：

• We are hard put to find a replacement for our assistant.我们很难找到一个人来代替我们的助手。
• They put all the students through the replacement examination.他们让所有的学生参加分班考试。

25 evergreen   

n.常青树；adj.四季常青的

参考例句：

• Some trees are evergreen;they are called evergreen.有的树是常青的，被叫做常青树。
• There is a small evergreen shrub on the hillside.山腰上有一小块常绿灌木丛。

26 cones   

n.（人眼）圆锥细胞；圆锥体( cone的名词复数 )；球果；圆锥形东西；（盛冰淇淋的）锥形蛋卷筒

参考例句：

• In the pines squirrels commonly chew off and drop entire cones. 松树上的松鼠通常咬掉和弄落整个球果。 来自辞典例句
• Many children would rather eat ice cream from cones than from dishes. 许多小孩喜欢吃蛋卷冰淇淋胜过盘装冰淇淋。 来自辞典例句

27 socket   

n.窝，穴，孔，插座，插口

参考例句：

• He put the electric plug into the socket.他把电插头插入插座。
• The battery charger plugs into any mains socket.这个电池充电器可以插入任何类型的电源插座。