zoomanallen

Those look like two different skulls. The first could be a beaver or muskrat, you can see the incisors that have broken off. but the second is a carnivore, like a fox or raccoon.

Defiantly a Virginia opossum

My first guess is a striped skunk, they kinda have the shortened skull like a cat but not as round. The size looks about right too. But to be certain closer pictures with more views would be best.

This is actually not a prairie dog at all but a rock cavy. I have seen them at a few zoos. What clued me in was the overall shape and color but also the animal is sitting on a rocky outcrop, prairie dogs would be on the ground.

Check out the photo on Wikipedia for a flying shot that's spot on. This guy must be right on the north edge of the year round resident range.

Judging by the narrow pelvis and the long metatarsals on the back legs (digitigrade) I would say domestic cat. Could be a raccoon, dog, or bobcat, but that seems the best with what I can see. Here are some references Cat Pelvis: http://vetmed.illinois.edu/courses/imagi...
Cat Skeleton: http://courses.washington.edu/chordate/4...

I found a half jaw just like this, minus the teeth, a month or two ago in Missouri. Its an opossum. Check out my spotting too. http://www.projectnoah.org/spottings/142...

Was this at a wildlife rescue?

Jellis, I'm gonna go with Easter gray squirrel. The links you posted are gray not fox squirrels, and I don't think you get the two species living in the same immediate area.

You really should spell out the entire scientific name.