The skulls of archosaurs were lighter than their reptile ancestors.

主龙类的头骨比 它们的爬行动物祖先轻。

Some archosaurs, like crocodylians, have been shown to exhibit general parenting behavior.

一些主龙，如鳄鱼，已被证明表现出一般的养育行为。

After the Permo-Triassic extinction, pseudosuchians were the first group of archosaurs to diversify and become common.

在二叠纪-三叠纪灭绝之后，伪鳄是第一批多样化并变得普遍的主龙类。

The End-Triassic extinction saw the end of many of the pseudo sukian archosaurs that were dominant during the Triassic.

三叠纪末的灭绝见证了许多在三叠纪期间占主导地位的伪苏氏主龙的终结。

Pterosaurs, another group of archosaurs (or " ruling reptiles" ) like the dinosaurs, may have developed feathers earlier than their dino cousins did.

翼龙是另一种像恐龙一样的祖龙（或“统治型爬行动物”)，可能比它们的恐龙表亲更早进化出了羽毛。

Most paleontologists consider pterosaurs to be a type of archosaur, a group that includes dinosaurs and crocodiles, among other things.

大多数古生物学家认为翼龙是一种主龙类，包括恐龙和鳄鱼等。

Around 250 million years ago, during the Triassic period, a class of reptiles called archosaurs split into two main groups.

大约 2.5 亿年前的三叠纪时期，一种叫做主龙的爬行动物分为两大类。

Arbour studied the tail anatomy of ankylosaurs and compared it to that found in living archosaurs, like crocodilians.

Arbor 研究了甲龙的尾部解剖结构，并将其与现存的主龙类（如鳄鱼）进行了比较。

Meanwhile, with these predators running around, another line of plant-eating archosaurs, the aetosaurs, came to be covered in bony armor.

与此同时，随着这些食肉动物四处奔跑，另一支以植物为食的主龙，即始龙，开始披上了骨质盔甲。

But after the extinction event at the end of the Cretaceous, the non-avian dinosaurs and other large archosaurs were gone.

但是在白垩纪末期的灭绝事件之后，非鸟类恐龙和其他大型始祖龙就消失了。