Not sure how to rate this as it's practically dead animals, but heck it's just schematic skulls. xD Picked moderate.

Anyway, for a school project I was asked to draw Guinea Pig skulls with different dentals for a game. The top left is how their teeth really look like (sorta), in the one next to it I replaced the teeth with those of a carnivore. Down left is pretty similar to the piggies' teeth, except they're slightly different and belong to a rabbit (notice the pivot tooth right behind the normal incisor!). Down right is a "Guinea Bird", literally just drew a beak onto the Guinea Pig skull. XD

I've got a fifth skull which I'll be uploading in a sec. :)

Feel free to use these by the way if you somehow find a use for them, but please give credit. Also they're in no way a good reference and you're better off using photos of skulls or schematic drawings out of proper books or something. I used references for these!