Re: selling skulls
You can sell any part of a fur bearing animal. There are tags required to ship fur out of the state but that applies to furs only. It has been too long for me to be sure about parts of CITES animals so you may want to check with the PGC regarding things like Bobcats.
When you are up to your butt in alligators, it is hard to remember your intent was to drain the swamp. Stay focused!