菊石是怎样灭绝的

• 作 者: 陈国先
• 出 处: 课外生活(小学版)
• 发表日期: 2004年06期
• 关键词: 菊石类 头足类 龟类 出纸 中所

对于菊石的突然灭绝消失，科学家做了多种原因的分析猜测。其中，流星撞击的假设一度很盛行。但在这次事件之前，菊石类其实就已经开始走下坡路了。海洋里有很多肉食类动物，如龟类、硬骨鱼类和鲨鱼，都比毫无防范的菊石游得快。可以说，它们都是菊石及其幼体难以应付的对手。

For the sudden extinction of the ammonite, the scientists did a variety of analysis and speculation. Among them, the assumption of meteor impact was very popular at one time. But before this incident, the asteroids have actually begun to decline. There are many carnivorous animals in the ocean, such as turtles, bony fish, and sharks, which swim faster than unprotected ammonites. It can be said that they are all rivals that are difficult to cope with.