Mebber,
Yautja,
11 years ago
Nice comparison, Bloo.
Well, let's assume xenos are eukaryotes and have bones, i think that would make them vertebrates, not mammals. Even if they have, as you assume, a tracea and lungs, they wouldn't be mammals necessarily, as reptiles and birds have them too. And i'm not sure xenos really HAVE a respiratory system like that, it could be something completely different. Or they don't breathe like we do at all. That alien in Alien seemed just fine within vacuum, and the facehugger survived in the original atmosphere of LV426 as well. It even managed to keep Kane alive for a considerable amount of time after his helmet has been breached. How did it supplied Kane with the necessary oxygen after the helmet wasn't air-proof anymore? It must had the ability to filter or transform the toxic atmosphere, otherwise Kane would have suffocated. That would at least indicate a different, more multifunctional kind of respiratory system as we know.
And there are many factors involved. As said, even reptiles, birds and mammals are different classes. They might share some features, but they differ in other fields, so they're not put together. And xenos GREATLY differ in some fields from anything we've seen on earth.
But it could be all wrong from the start. The xeno has a cleary alien physiology and biochemistry - i mean, it contains molecular acid in its own metabolism. Stuff that eats through steel like a hot knife through butter. It's even possible their entire cell structure differs so greatly from anything on earth that they aren't true eukaryotes, or anything else encountered on earth. I think the only definite thing we can assume is that they're multi-cellular lifeforms.