Well, if the feathered dinosaurs layed the egg, which became a chicken, then wouldn't the answer count as chicken because the ancient featured dinosaur chicken layed the egg!![]()
![]()
Maybe a good way to think about it is as a breed. The feathered dinosaurs can't be chickens because A) They don't meet the breed description and B) They don't breed true.

Now whether or not the egg itself is a CHICKEN EGG is a bit trickier - I'd say it isn't a chicken egg but it still hatched out a chicken, much like it's not an olive egger egg, but still hatched out an olive egger.
But either way, the egg was there and the chicken wasn't. The egg existed, even though the olive egger didn't yet exist.