Re: Anatomy does not work that way...
I see your point here, but it's a poor example, because Spock's ears are ridiculous. All TOS aliens are more-or-less ridiculous, but especially Spock and the Klingons.
Look, it's supposed to be a cat. Draw a cat. If they'd drawn a cat, we wouldn't have this conversation. If it's an alien cat, draw an alien cat. Make it consistent. Again, we'd have no need to discuss it if it wasn't clearly and completely wrong. Wrong by its own standards. Wrong.