> Wasn't the holotype skull of _Archaeornithoides_
> chewed on by a small
> mammal?
haven't seen the paper, but couldn't that be due to
scavenging?
Certainly. But this could also apply to _Repenomamus_. We don't know for
certain if the juvenile psittacosaur was alive or dead when the mammal came
up on it.
Ironically, the only time we know for sure that a long-extinct animal was a
predator (i.e., attacking live prey) is when the intended prey survives the
encounter, carrying injuries that subsequently heal imperfectly, leaving
proof of the attack.