THOSE are the features that you consider to differentiate between apes & humans??? Wow.
Our old cat, Lightbulb (RIP), had always had a saggittal crest. Our younger cat, Neko, does not. I once knew a kid in HS who had two rows of teeth (4 in all), and IIRC a common dental problem is when you have too many teeth for your mouth. (Not referring to wisdom teeth; it's something else.) And there's large variation in the shape of people's jawbones. Compare Richard Kiel vs. Bobby Darin.
