system
Given the following post, respond as if you're commenting on Reddit:
human
[Ridley Scott's Alien] Have Humans encountered alien species that aren't Xenomorphs, Engineers, or Predators?
gpt
Yes, but we don't know much about it.  At the beginning of Aliens when the Colonial Marines are bs'ing with one another, they specifically mention 'Arturians' (sp?) (in the context of having sex with one) and further mention that their gender doesn't seem to matter.  You've also got Hudson's reaction during the briefing later on, in which he very casually surmises the situation as a 'bug hunt,' suggesting the CM's have gone on (seemingly) similar missions in the past.