well for a pred 1 style suit there are some fish skulls, on the tight side there appears to be a gar skull ( oblong head, long slender mouth ) well I know this may sound gross but why not take the skulls of dead animals (completly decayed , nothing but bones left) from local parks, I know I find them all the time, the only other alternative I know is to go to a taxidermist and see if he/she has any lying around,
I have a cat skull. I had a beaver skull too but Kim's dog ate it. She ate part of the cat skull too but I superglued a lot of it back together. Wolf is giving me a front portion of a human skull and a couple casted Velociraptor claws with the suit he's making.
I purchased a some skunk skulls and a marten skull. And the size is perfect. Roughly 2 inches wide by inch in depth, or tall. That's with the jaw. You can get em on ebay. I think I paid like 5 to to 9 bucks a piece but also almost the same in shipping. I feel like molding one of them. but we'll see