包含已知最古老的动物化石的埃迪卡拉化石组，只含有软体动物。

The Ediacara fossil formation, which contains the oldest known animal fossils, consists exclusively of soft-bodied forms.

youdao

关于在这一亿年的重要时期中没有化石，有一种解释是，早期的动物是软体动物，根本不会变成化石。

One interpretation regarding the absence of fossils during this important 100-million-year period is that early animals were soft-bodied and simply did not fossilize.

youdao

在这重要的一亿年的周期内缺乏化石（记录），关于这一点，有一种解释是早期的动物是软体动物，所以它们无法形成化石。

One interpretation regarding the absence of fossils during this important 100-million-year period is that early animals were soft bodied and simply did not fossilize.

youdao

That's for a different lecture So, anyway, thermodynamics dates from the same period as getting fossil fuels out of the ground. It's universal.

这是另一堂课的内容,不管怎么说,热力学与开采化石燃料,起源于同一时期，它是普适的。

麻省理工公开课 - 热力学与动力学课程节选

I don't see dinosaurs, but of course they leave traces behind in fossils.

我没见过恐龙，但是无疑的,他们留下了化石这样的痕迹。

耶鲁公开课 - 死亡课程节选