>>5641838> cephalopodsOne of the smartest nonhumans, but aquatic life doesn't have access to the tech path that generates the materials needed for space vehicles and most other advanced technology. And endoskeletons kick the shit out of the cephalopod and all invertebrate body mechanics for large (all smart animals are "large") land animals.
>plants, fungiAutotrophes and decomposers do not have an evolutionary incentive to develop intelligence. In the real world, all smart animals are hunters and/or highly social, usually both. Guess what the two most intelligence-demanding tasks most animals do are.
>that look nothing like any 'eyes/nose/mouth' combo we are used toWe're used to it for rather good reasons. The main underlying reason is nerve transmission delays. Neural computation is faster when signal travel time is minimized, so organisms that need it cluster most of their processing equipment into a brain. Brains can respond to stimuli faster if sensory equipment is close to it, again minimizing signal travel time. Taste being the most fundamental sense (even bacteria have it), anything with a brain is going to have a mouth equipped with a sense of taste near its brain. Eyes are extremely useful, and have evolved multiple times independently on Earth. Two eyes allow 3D vision, and more than two seeing a particular field of view is an unnecessary expense. An alien organism might have several shitty simple eyes, but if it has good eyes capable of resolving detail, it will probably only have two. If an organism moves around in a gravitational field, bilateral symmetry is generally the most effective symmetry scheme for all but the simplest behaviors.
So are weird starfish or Lovecraftian aliens possible in principle? Sure, but in a plausible evolutionary history, such body plans would have probably been outcompeted by more effective versions long before intelligence had the chance to arise.
