Skulls

 
Raccoon & Badger:
The skull on the left is from a large raccoon. The skull on the right is from a large American badger.
 
Possum & Red Fox
The skull on the left is from an average-sized Virginia Possum, the skull on the right is from a fairly large red fox.
 
Groundhog & Skunk
The skull on the left is from an average-sized groundhog, the skull on the right from a striped skunk.
 

All six skulls, shot from above.
The top two are a large raccoon (left) and a large American badger (right). The skull in the middle is a average-sized groundhog. The small skull on the far left that is turned vertically is a striped skunk. The small skull on the far right is a Virginia Opossum. The long skull on the bottom is a fairly large red fox.