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.

Shade Garden Plants

I'm not sure what this plant is but it lives in my shade garden and spreads via little runners.