image: Google Images
the chambered nautilus is part of the cephalopoda class, i.e. a kind of octopus/squid. it has about 90 tentacles with no suckers, and a tube running down the center designed to release gas that has the same density as sea water, so that it may remain afloat and exert the bare minimum of energy to swim. this feature has not evolved for the past 500 million years.
why evolve when you’re already awesome?