First one shown individually I believe is a Barred Rock. The comb is wrong for a Dominique and skin color is wrong for a Marans.
Second is an Ancona. I don't see anything else in McMurray's catalog that looks like this.
Third appears to have a single comb, so not a Brahma. I believe that's a Black Cochin as I see yellow on its feet.
Fourth, the ugly duckling, I believe is a Silver Spangled Hamburg. A shot of its comb would help to confirm.
Fifth and sixth, the pterodactyl and the orange ones, are all Red. Those first feathers often have some black speckling like that in hatchery-quality Red breeds. As for their actual breed, I'm inclined to say that they're Rhode Island Reds, but the way you describe pterodactyl as skinnier makes me wonder if she could be one of McMurray's Red Leghorns? New Hampshire is also a possibility for any of them, but those tend to be paler.
Number seven, I believe you are correct in guessing White Leghorn.
Eight, I believe are Easter-eggers. The green legs kind of pushed me in that direction, but a view of their combs would help to confirm.
Nine, Tiger, if that's the same chick visible in the background of breed eight's picture, is a Gold Laced Wyandotte. The comb is incorrect for a Barnevelder and I don't see that breed in McMurray's catalog anyway.
I believe ten and eleven, the chipmunk striped babies, are Easter-eggers as well. Ten appears to have a pea comb and eleven has puffy cheeks.
I think I got all of them, and to the best of my knowledge.
It will be easier to know for sure on the trickier ones (especially the Reds) once they've grown more and are more feathered in, so please check back in a month or so with update pictures!