if you want to unlock all parts this is how without looking for bones.
at the spore main menu press Ctrl + Shift + C
Then Type levels -unlock
This will allow you to unlock every stage for new games, even if you haven't completed their prerequisite stages this will also give you all the Create a Creature Modes.
well i still want to play through the whole game. from cell to space so in doing this won't i still have to find all the parts in creature mode?