I have heard biologists argue that intelligent alien species that evolved off-earth probably would not have a face: two eyes, a nose and a mouth. They see that as an accident of evolution. I am not so convinced. Having the eyes on top gives greater range of vision. Two eyes are needed for 3D or to see to both sides. Having the mouth on the bottom puts it closer to the prey, especially for animals whose ancestors routed in the mud. I could see a single nostril instead of two, but two small ones probably helps keep out insects and debris. Humans have a fatal design flaw, taking air down the same tube as food. I would not be surprised if aliens were free of that defect.
~ Roedy (born: 1948-02-04 age: 64)