英语语法分析

Extinct but already fully marine cetaceans are known from the fossil record.

从化石记录中可以了解到一些已经灭绝、但已经完全变成海洋生物的鲸目动物。

The whale retained a tail and lacked a fluke, the major means of locomotion in modern cetaceans.

这种鲸保留了尾巴，没有现代水生鲸类动物用于行动的主要部位，尾片。

Although limited to a skull, the Pakicetus fossil provides precious details on the origins of cetaceans.

虽然只有一个头骨，但帕基塞图斯化石提供了有关鲸类起源的珍贵细节。