Scientists Discover New Dinosaur with Dangerous Tail

Scientists in Chile have discovered the bones of a dinosaur¹ they say used its unusual tail as a deadly weapon.

Researchers say the dog-sized creature had a tail weapon unlike those seen on any other animal. The tail had a series of "blades" on each side that could be used to cut its enemies.

At first, the scientists thought the plant-eating dinosaur might have belonged to a similar species called stegosaurus. But after studying pieces of skull² and examining DNA³, the scientists decided⁴ the dinosaur must be from a new species.

The researchers named the dinosaur stegouros because of its similarities to stegosaurus.

The find is described in a study recently published in Nature. Alex Vargas was the lead writer of the study. He told The Associated Press that the animal's blade-like tail could be used as a cutting weapon similar to those used by Aztec warriors⁵.

"It's a really unusual weapon," said Vargas, a scientist with the University of Chile. He said information on the species should be added to books on prehistoric⁶ animals for children. "It just looks crazy," Vargas added.

The bones, or fossil, is from about 72 million to 75 million years ago, the team said. Researchers believe the animal is part of the ankylosaur family of dinosaurs⁷. They are believed to have walked the Earth throughout the Jurassic and Cretaceous periods.

The scientists say the dinosaur must have been a rare southern hemisphere member of the family. Vargas called it "the lost family branch of the ankylosaur."

The fossil appears to be an adult based on the way the bones are connected, Vargas said. It was found with its front end flat on its stomach. The back end sat at a lower level, almost as if caught in sand, he added.

The tail was probably used as a defense⁸ against large predators¹⁰. Vargas said the animal's enemies were also likely persuaded not to attack by armor-like bones that made stegouros "chewy."

Not only is this "a really bizarre tail," but it is from far southern Chile, said Macalester College biologist Kristi Curry¹¹ Rogers. She was not part of the study. Rogers said discoveries of that kind of animal have not been made in the area before.

She added that the finding shows that scientists are "just scratching the surface" when it comes to understanding the many different kinds of dinosaur species. "Stegouros reminds us that if we look in the right places at the right times, there is so much more still to discover."

Words in This Story

dinosaur – n. a very large animal that used to live millions of years ago

blade – n. the flat part on a knife or similar tool or weapons

species – n. a group of animals or plants that are similar and can produce young animals or plants

predator⁹ – n. an animal that hunts and kills other animals for food

chewy – adj. needing to be chewed a lot before being swallowed

bizarre – adj. very strange and surprising

scratch the surface – phr v. to deal with only a small part of a subject or problem

remind – v. make someone think of something they have forgotten about

1 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。

2 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。

3 DNA   

(缩)deoxyribonucleic acid 脱氧核糖核酸

参考例句：

• DNA is stored in the nucleus of a cell.脱氧核糖核酸储存于细胞的细胞核里。
• Gene mutations are alterations in the DNA code.基因突变是指DNA密码的改变。

4 decided   

adj.决定了的，坚决的；明显的，明确的

参考例句：

• This gave them a decided advantage over their opponents.这使他们比对手具有明显的优势。
• There is a decided difference between British and Chinese way of greeting.英国人和中国人打招呼的方式有很明显的区别。

5 warriors   

武士，勇士，战士( warrior的名词复数 )

参考例句：

• I like reading the stories ofancient warriors. 我喜欢读有关古代武士的故事。
• The warriors speared the man to death. 武士们把那个男子戳死了。

6 prehistoric   

adj.（有记载的）历史以前的，史前的，古老的

参考例句：

• They have found prehistoric remains.他们发现了史前遗迹。
• It was rather like an exhibition of prehistoric electronic equipment.这儿倒像是在展览古老的电子设备。

7 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》

8 defense   

n.防御，保卫；[pl.]防务工事；辩护，答辩

参考例句：

• The accused has the right to defense.被告人有权获得辩护。
• The war has impacted the area with military and defense workers.战争使那个地区挤满了军队和防御工程人员。

9 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。

10 predators   

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》

11 curry   

n.咖哩粉，咖哩饭菜；v.用咖哩粉调味，用马栉梳，制革

参考例句：

• Rice makes an excellent complement to a curry dish.有咖喱的菜配米饭最棒。
• Add a teaspoonful of curry powder.加一茶匙咖喱粉。