daveberg,
Undefined,
17 years ago
I'm unsure of how they would link it.
As far of the crew of the Nostromo and Ripley go, they had never heard or known of contact with such creatures.
If there is a link, then obviously it's a military issue, classified files and data taken from the incident/incidents - which worked its way up through the government and high profile corporate companies *Insert Weyland Yutani here*
Other than that, the time line has to be precise, human society has to be excluded from knowing about the interaction with the Xenomorphs, else everyone would know about the imposing threat and the fact that there was indeed, extra terrestrial life out there - which would have been sufficient enough data to provide to a deep core mining team in outerspace, and have them prepare for conflict with any 'Large, nasty beasts'