What is a shared derived character or synapomorphy of pachycephalosaurs?

什么是厚头龙的共同衍生特征或联结形态？

Although pachycephalosaurs have all of these features, it is only the thicken, domed skull that all pachycephalosaurs share.

尽管厚头龙具有所有这些特征，但所有厚头龙共有的只是加厚的圆顶头骨。

What they've shown is that pachycephalosaur domes could actually have withstood an enormous amount of force.

种种证据表明，肿头龙的圆顶真的可以承受巨大的冲击力。

We now believe pachycephalosaurs used their head both as a formidable weapon and as a colorful display.

我们现在相信厚头龙既把头部当成可怕的武器，也当成五彩斑斓的展示品。

The most distinctive feature about the pachycephalosaurs, of course, is this really weird dome that they have on their head.

肿头龙最显著的特征，当然是它们头上那个非常奇怪的圆顶。

So, were the skulls strong enough to protect pachycephalosaur's brain after all?

那么肿头龙的头骨到底够不够坚固以保护它们的大脑呢？

The Pachycephalosaur headbutting theory suggests that two rival pachycephalosaurs may have charged head-long into one another and collided skull dome to skull dome.

Pachycephalosaur headbutting 理论表明，两只竞争的 pachycephalosaurs 可能已经冲向彼此，头骨穹顶与头骨穹顶相撞。

A pachycephalosaur was found, with marks showing it had survived multiple injuries to the top of its head, and it wasn't a one-off.

一只肿头龙被发现后，其头上的痕迹表明它曾多次受伤并活了下来，而且这并不是一次性事件。

They sliced up a number of pachycephalosaur domes, and when they did that, they found out that maybe it wasn't strong enough to withstand these direct head-on impacts.

它们切开了一些肿头龙的圆顶头骨，在这个过程中，他们发现其强度也许不足以抵御迎头撞击。

They went back and looked through historic museum collections and discovered that actually there was quite a lot of evidence for these lesions in a similar place across a whole bunch of different pachycephalosaurs.

于是人们回头去检查历史博物馆里的藏品，发现其实有很多化石存在这样的损伤，遍布众多肿头龙当中的类似部位。