What allowed these titanosaurs to grow so big?

是什么让这些泰坦龙长得如此巨大？

But the colossal crown goes to a group of sauropods called titanosaurs.

但巨冠要颁给蜥脚类恐龙中的泰坦龙。

They're not the biggest titanosaurs. One of them named argentinasaurs is thought to have been as long as 115 feet.

它们不是最大的泰坦龙。其中一种名为阿根廷泰坦龙，据信体长115英尺。

Because of titanosaur's size, their metabolism was very energy efficient.

由于泰坦龙体型巨大，新陈代谢率非常高。

Reaching enough food wasn't a problem for the titanosaurs and other sauropods either.

获得充足的食物对泰坦龙和其他蜥脚类恐龙来说不成问题。

Unlike most other reptiles, titanosaurs had some bones that were hollow and filled with air.

与大多数其他爬行动物不同，泰坦龙的部分骨头中空，里面充满了空气。

Firstly, titanosaurs had a strong, stable body shape, including four pillar-like legs, sturdy joints and wide-set hips.

首先，泰坦龙有着强壮、稳定的体型，包括四条柱状腿、结实的关节和宽阔的臀部。

But it's unlikely any would quite fill the shoes of the titanosaurs.

但仍不能完全取代泰坦龙的位置。

Although titanosaurs like Patagotitan did have special features to help keep them cool.

尽管像巴塔哥尼亚龙这样的泰坦龙确实有独特的特征来帮助它们保持凉爽。

If you had a whale and a titanosaur of the same length, the titanosaur would weigh much less.

假设一只长度相等的鲸鱼和一只泰坦龙相比，泰坦龙会轻得多。

However, just like titanosaurs, their size makes them more vulnerable to habitat loss, food shortages and climate change.

然而，就像泰坦龙一样，它们的体型使它们更容易受到栖息地丧失、食物短缺和气候变化的影响。

As energy efficient as titanosaurs were, bigger animals need more food than smaller ones.

虽然泰坦巨龙很节能，但体型较大的动物比体型较小的动物需要更多的食物。

But the current record holder for the largest specimen belongs to the newly-named titanosaur Patagotitan.

但目前最大标本的纪录保持者属于新命名的泰坦巨龙 Patagotitan。

All of these different body features combined were a big part of titanosaurs growing so large, but one other key element was their mighty metabolism!

所有这些与众不同的身体特征综合起来，造就了巨型泰坦龙，而另一个关键因素就是它们强大的身体代谢！

But scientists say the recently discovered fossils are older than those of other types of titanosaurs and that suggests that ninjatitans might have pre-dated other dinosaurs that looked like them.

但科学家们表示，最近发现的化石比其他类型的泰坦龙化石更古老，这表明忍者泰坦龙可能比其他看起来很像它们的恐龙更早出现。

In the traditional dinosaur family tree, this group encompasses the theropods -- that is, the two-legged dinosaurs that include today's birds -- as well as the sauropods, the quadrupeds that include the giant titanosaurs.

在传统的恐龙家谱中，这一组包括兽脚类恐龙——即包括今天的鸟类在内的两条腿的恐龙——以及蜥脚类恐龙，即包括巨型泰坦龙在内的四足动物。