I have one Barred Rock and one Maran and I used to know which one was which. The BR was a little older and bigger and the Maran had a blacker back between the wings. Now I have no clue! They are a little older and similar in size and both seem to have white markings on their backs. One chick has markings on its beak, more white markings on its head and the other has a beak with no markings and sort of a skunk look with a white area on its neck and belly and on top of its head. I think the second one might be the Maran but any guesses are welcome!