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While the movie and its sequel have been officially omitted from the official time-line of Alien films (which subsequently also omits the Predator films from the time-line), it could still potentially fit in with the official time-line for a variety of reasons, most important being that the origins of either the Predator or Xenomorph species has never been explained within the context of AVP or Requiem.
In an interview, director Paul W.S. Anderson said that Arnold Schwarzenegger offered to reprise his role as Dutch Schaefer (from Predator (1987)) at the end of this movie as a cameo, but only if he lost the election for California Governor. Schwarzenegger famously won the election, so he was unavailable to appear.
The Antarctic setting on Bouvet Island is based on the unexplained "Vela Incident" of September 22, 1979, where a satellite recorded a flash of light near the island. It was first speculated to have been a man made nuclear explosion, or a natural event, such as a meteor strike, but this has never been resolved.
When Lex asks Sebastian how to say "scared shitless" in Italian, he replies "Non vedo l'ora di uscire da questa piramide con te, perché mi sto cagando addosso." Translated, this literally means "I can't wait to get out of this pyramid with you, because I'm shitting myself."
The Alien Queen was the most sophisticated animatronic ever built at the time. It had twice as many moving parts as the T-rex from Jurassic Park (1993).
The altars where victims were placed in the Chamber of Sacrifices of the pyramid are arranged identically to the hibernation pods in the original Alien (1979).
Tom Woodruff Jr., Alec Gillis: After the opening credits are shown, special effects designers as the technicians who discover the heat bloom coming from the pyramid.
Liz May Brice: as a Supervisor at the Weyland Industries Receiving Station. Brice played the Umbrella team medic in Resident Evil (2002), which was also directed by Paul W.S. Anderson, and also featured Colin Salmon.