Frequently, these were taken by theropods.

这些恐龙经常被兽亚目食肉恐龙捕食。

Instead of theropod footmarks, they found those of crocodilians.

他们发现的是鳄鱼的足迹，而不是兽的。

But that does not completely explain the absence of theropod tracks.

但这并不能完全解释兽亚目食肉恐龙的缺位。

Like the theropods, these titans used air sacs to breathe and had light, hollow bones.

兽亚目恐龙一样，这些巨人使用气囊来呼吸，而且有轻的中空骨骼。

All the known sets of prints that show speed come from a family of dinosaurs called theropods.

所有已知的能测出速度的来自兽足亚目恐龙家族。

While Triceratops and Stegosaurus grew up to eight meters long, bird-like theropods like Tyrannosaurus grew twice as large.

当三角龙和剑龙长到八公尺长时，暴龙这样的兽亚目恐龙长了两倍大。

Unfortunately, for Majungasaurus and most theropod dinosaurs, we don't have a lot of specimens to work with.

遗憾的是对于玛君龙和多数兽恐龙来说我们没有多标本。

In that sort of environment even a big theropod would constantly have been looking over its shoulder.

在那样一种环境下，即便是一头巨大的兽亚目食肉恐龙也会不时回头张望。

And one of the problems of the teeth though, is they certainly are not as strong as other teeth in theropod dinosaurs laterally.

但是这些牙齿的问题之一是，横向上它们肯定没有其它兽亚目恐龙的结实。

Presumably, it was lost by their theropod ancestors, which did not need it. Dr Toda's and Dr Baldwin's experiments have shown how this loss was reversed.

据推测，它是兽亚目动物的祖先遗失的，它们并不需要它。户田博士和鲍德温博士的实验显示了这种损失是如何逆转的。

This is from the foot of Utahraptor, and it's unlike the claws in the feet of other theropods in that it's very narrow, you can see, it's narrow in section.

这来自犹他盗龙上的，它不其它兽恐龙的爪，它非常窄，你能看到，这部分窄。

Meat eaters need not detect sugar in the way that, say, fruit eaters do, and genetic analyses of modern birds suggest their theropod ancestor had lost the ability to taste sweetness.

肉食者不需要水果食者那样检测糖分，对现代鸟的基因分析表明，它们的兽亚目祖先已经失去了品尝甜味的能力。

Once we look at theropod dinosaurs, virtually any species where we have multiple specimens, we do see that they tends to be two morphs or two type once they get to adult stage.

只要我们观察兽恐龙，对于有多个样本的物种能看到在其成年阶段会有呈两种形态的趋势。