Dinosaurs Are Different

Dinosaurs Are Different

不一样的恐龙

I like to visit the dinosaurs. I like to study their skeletons. I have found out a lot about dinosaurs by looking at their bones.

我喜欢看恐龙。 我喜欢研究它们的骨架。 通过观察这些骨头，我学到了很多关于恐龙的知识。

The minute l saw Tyrannosaurus, I knew it was a meat-eater. A meat-eater's teeth are long and pointy. But lguanodon could never chew meat. Its teeth are too flat. They were made for crushing and grinding plants. I noticed something else. Look at their hips. Tyrannosaurus has a big bone pointing forward. Iguanodon doesn't.

我一看到霸王楼就知道它是肉食动物。 肉食动物的牙齿又长又尖。 禽龙从不吃肉。 它的牙齿又扁又平，便于咀嚼和碾碎植物。 我注意到一些不同之处。 请看它们的臀部。 霸王龙有一块大大的骨头，指向前方。 禽龙则没有。

I looked at other skeletons. I saw that some dinosaurs have hips like Tyrannosaurus. Others have hips like lguanodon. I wondered what this meant. I soon found out. Dinosaurs are different.

我还看了其他恐龙的骨架。 我发现有一些恐龙的臀部和霸王龙一样。 另一些的臀部则和禽龙一样。 我不清楚这意味着什么。 但很快我就找到了答案。 各种恐龙是不一样的。

Tyrannosaurus and lguanodon were cousins. Each belonged to a different order of dinosaurs. Tyrannosaurus was a SAURISCHIAN dinosaur. lguanodon was an ORNITHISCHIAN dinosaur. Saurischia and ornithischia belong to a larger group called ARCHOSAURIA-” ruling reptiles. ” There were others in the archosaur group-THECODONTS, CROCODILIANS, and PTEROSAURS. But there were more dinosaurs than other archosaurs. Dinosaurs ruled the earth for 140 million years.

霸王龙和禽龙是亲戚,分属于不同的目。 霸王龙属于蜥臀目的恐龙。 禽龙则是鸟臀目恐龙。 蜥臀目和鸟臀目同属于一个大类群，叫做主龙类。 主龙类还包括鳄目和翼龙目。 在主龙类中，恐龙居多。 恐龙统治了地球一亿多年。

All dinosaurs are either saurischians or ornithischians. They are divided into these two separate orders because they have different structures. One big difference between the two groups is their hips.

根据身体构造的不同，恐龙被划分为两个不同的目，也就是蜥臀目和鸟臀目两个目最大的区别在于它们的臀部不一样。