That's odd and a mistake I think. We have the blue Dino one and it's adorable but huge! We have it in 3T and maybe 5T. My son wore the 3T one well after he was done with that size in everything else. Last year DD wore the smaller one (she was wearing 3T in most everything and we had to roll up the sleeves many times!) and DS, who wore a 6/7 could still fit in the 5T although it was getting tight.
Not sure if this link will work but here's a picture of them last September in their matching coats:
http://www.facebook.com/photo.php?pi...&id=1501906032