More Skull Photos

Still don't have a positive id on this skull. It was found in the green belt are near the Skunk River, central Iowa. 

Unknown Skull

I was told that this was an opossum skull, but I'm not so sure it is...

???

The plants were about three to four feet tall.

Name that Plant

Rattlesnake Master or Eryngium yuccifolium

Canada Anemone or Anemone canadensis

I took these plant pics in a prairie reclaimation area that was recently under water due to all of the flooding.