Can you tell a 'regular' chick from a bantam chick?

[Nonny]

Still wondering why one of our chicks hasn't grown much and is half the size of the others, and I asked the supplier who said maybe there was a mixup. She certainly looks like a light sussex, but I've read that they come in bantam as well.

If I've ended up with a bantam light sussex, is there a way to tell, or do I just have to wait until she's fully matured?

 

[Nonny]

Hmmm.... I've sent ages googling and all I can find about bantams is that they are smaller than regular chickens, and lay smaller eggs. Which doesn't help me figure out if our chick is one.

Guess I'll have to wait about 5 more months LOL.