These sizes are exceptional among theropods.

这种体型目恐龙中是罕见的。

Such a predator would have been unable to take on an adult ornithopod.

这样的掠食者本不能捕食一头成年鸟目食草恐龙。

Birds evolved from a grouping of dinosaurs known as theropods in the late Jurassic.

鸟是从侏罗纪晚期的目恐龙进化而来的。

Most, but not all, were ornithopods.

绝大部分是鸟目食草恐龙。

The theropod group includes all the meat-eating dinosaurs like Tyrannosaurus.

目恐龙包括所有诸如暴龙之类的食恐龙。

That is certainly large enough to take on an adult ornithopod.

大到足以捕杀一头成年鸟目食草恐龙。

Natovenator is part of the dinosaur group called theropods.

非鸟类恐龙是被称为目恐龙群体的一部分。

He believes there will be more discoveries of peculiar theropods in the future.

他相信未来还会发现更多奇特的目恐龙。

Or tiny, like the haplorhine clade of monkeys, tarsiers, and apes.

进化枝也可以很微小，如猴子、眼镜猴、猿猴等目。

Some small theropods grew quickly and others grew slowly.

有些小型目恐龙生长得很快，而另一些则生长缓慢。

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印都来自足目恐龙家族。

The researchers examined rings called " cortical growth marks" in different theropod species.

研究人员检查了不同目恐龙身上被称为“皮层生长痕”的圆形标记。

Pinnipeds-walruses, seals and sea lions. And parrots, hummingbirds and songbirds. That's it.

再加上海象、海豹和海狮等鳍足目动物，以及鹦鹉、蜂鸟和鸣禽。全部就是这些。

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

像目类恐龙一样，这些巨人使用气囊来呼吸，而且有很轻的中空骨骼。

He said, " The diversity of theropod dinosaurs by the end of the Cretaceous is totally amazing."

“到白垩纪末，目恐龙的多样性令人惊叹。”

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

但这并不能完全解释目食恐龙的缺位。

But, the animal's closest relatives and almost all bird-like theropods have feathers.

但是，这种动物的近亲和几乎所有形似鸟类的目恐龙都有羽毛。

The two-legged dinosaur was the size of a large bird and weighed about as much as a house cat.

鸟面龙这种目恐龙有一只大型鸟类那么大，体重约相当于一只家猫。

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，像暴龙这样的目类恐龙长了两倍大。

But even for these early theropod dinosaurs, the one we've now discovered is actually very, very small.

但即使是这些早期的目恐龙，就是我们现发现的这种恐龙，真的非常非常小。