VOA常速英语:阿根廷科学家发现新型恐龙

Cretaceous period n ph. 白垩纪时期

The temperature drop during the Cretaceous period would almost certainly have wiped out an 'abundance' of the world's dinosaurs.
曾经称霸地球显赫一时的恐龙，在白垩纪时代的这次温度巨变中，似乎全都灭绝了。

2. The strata of this age, the sediments of a hundred and forty million years ago, are rare across the world,

strata n. 【地质学】地层

But the research team concluded that those anomalies were created by jumbling of strata when debris flowed back into the crater after the impact.
但是研究小组得出的结论是，那些异常现象是由于撞击之后碎块返回陨石坑时引起的地层混乱造成的。