what is a vaulted skull in silkies?

[flowerchicks]

I hear the term vaulted skull but I have know idea what it means. It is supposed to make silkie more susceptible to injury by pecking, I have heard. Do all silkies have vaulted skulls? If not, how do you tell if one does?

 

[Ms.FuzzyButts]

Quote:
No, not all silkies have them. How you can tell is fairly simple. When they are born is the easiest. If it has one, there will be a noticeable bump on its head, otherwise it will be like any other chick with a smooth head.