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1·Tortoises have hard shells.

乌龟有坚硬的壳。

2·Both these fossils were dry-land tortoises.

这两块化石都是旱地陆龟。

3·Tortoises therefore represent a remarkable double return.

因此，乌龟是曾经往返于陆地和水中生存的代表性物种。

4·Crocodiles, tortoises, birds, and insects seem to have been little affected.

鳄鱼、乌龟、鸟类和昆虫似乎很少受到影响。

5·Animals which behave frugally with energy become particularly old, for example, crocodiles and tortoises.

对能量使用表现得很“节俭”的动物变得非常长寿，比如鳄鱼和龟类。

6·Today's land tortoises constitute a single branch, deeply nested among branches consisting of aquatic turtles.

现在，陆龟构成一个独立的分支，完全被淹没在海龟的分支当中。

7·Targland's officials predict that these measures will be adequate, since it is difficult to collect the tortoises without a vehicle.

塔格兰德的官员预测这些措施将是足够的，因为没有交通工具的话，很难收集这些乌龟。

8·Sure enough, these amphibious species show up on the triangular graph approximately half way between the wet cluster of sea turtles and the dry cluster of land tortoises.

可以肯定的是，这些水陆两栖物种的数据出现在接近三角坐标中间的位置，位于水栖海龟和陆栖乌龟的坐标点之间。

9·Finally they returned yet again to the land as tortoises, some of which now live in the driest of deserts.

最终，它们再一次回到陆地，进化成为陆龟，其中的一些现在生活在非常干旱的沙漠中。

10·Because tortoises are the key.

因为，陆龟是其中的关键。

(1)tortoise shell龟甲；一种类似龟甲的蝴蝶