Dinosaurs rapidly became extinct about 65 million years ago as part of a mass extinction known as the K-T event, because it is associated with a geological signature known as the K-T boundary, usually a thin band of sedimentation found in various parts of the world. (K is the traditional abbreviation for the Cretaceous, derived from the German name Kreideieit). ( TPO42, 60)
abbreviation /?'briv?'e??n/ n. 简略，缩短
derive /d?'ra?v/ v. 获得，得到;源自，源于
分析：
这个句子的主干就是：
Dinosaurs rapidly became extinct about 65 million years ago
修饰一：(as part of a mass extinction) ，介词短语
中文：成为大灭绝事件的一部分
修饰二：(known as the K-T event) ，非谓语动词
中文：称之为K-T事件
修饰三：(because it is associated with a geological signature) ，从句
中文：因为它与地质学上的标签有联系
修饰四：(known as the K-T boundary) ，非谓语动词
中文：称为之K-T边缘
修饰五：(usually a thin band of sedimentation found in various parts of the world) ，同位语
中文：K-T边界通常是一块在世界各地都能找到的薄薄的沉积带
修饰六：(derived from the German name Kreideieit)，非谓语动词
中文：源自德国名字kreidezeit
参考翻译：
大约在6500万年前，恐龙迅速地灭绝，成为K-T大规模灭绝事件的一部分，被称作K-T是因为它与地质学上的标签K-T边界有关，K-T边界通常是一块在世界各地都能找到的薄薄的沉积带。(K在惯例上是白垩纪Cretaceous的缩写，源自德国名字kreidezeit)