Who's who in the zoo

So here we have a picture of Booster and Lolly.  I mentioned yesterday that I am starting to wonder if they are actually different types of Bearded Dragons.  I thought it might be worth expanding on this a bit.

From what I have read so far, there are 7 species for the Genus Pogona (Bearded Dragons).  They each have their own traits that mark them different from each other.  Although my Biology teacher at school said that a key indicator for a species was that when mated they could produce fertile offspring.  I haven't read anything one way or the other, so it will be an interesting thing to read if I can find it.

If you look at the photo here, you can see a bit of what I mean about the differences in the two dragons we have.  On the left is Booster.  You can see he is more patterned on his back and lighter in colour.  On the right is Lolly.  You can see that the sides of her back are without patterned markings and she is darker. 

So I am wondering if Booster is a Central (or Inland) Bearded Dragon (Pogona vitticeps) and Lolly is an Eastern Bearded Dragon (Pogona barbata).  From what I understand, the Central Beardies don't grow quite as big and are more sandy in colour that the Eastern Beardies. I am sure it is way too early to tell, but, it will be interesting to see.  It's probably nothing more exciting that some different variation in the young of the same species.  But it's fun to ponder.