I hope chickensrock12 is right, because I got some of these chicks from Tractor Supply too, and my son just noticed last night that they have extra toes! It's so weird, we didn't even notice till he pointed it out to us. They look exactly like the pictures you posted.
The local TSC we bought from sold them as "Black Asians" and since they were a straight run, we didn't know what we were getting. I noticed one had a larger comb than the other two, and decided it must be a rooster while the two with smaller combs were hens.
If chickenrock12 is right, this extra toe thing might be an indicator of sex with this strange variety of chicken--the two chicks with smaller combs (that I thought were female) have extra toes, and the one with the larger comb (betting he's a rooster!) has NO extra toes. Can't wait to see!!!