Precursors

The term Precursor refers to any advanced alien species (spacefaring, generally) that is now extinct or extant. Precursors often possessed advanced technological capabilities, beyond those of the species which currently inhabit the galaxy. The ruins of their civilizations still dot the cosmos, and though most are merely archaeological curiosities, some still possess the technological secrets of these ancient civilizations.

One of the most influential Precursor species were Humans, who still exist in scattered pockets today. The humans' empire, the details of which have been lost to the ages, spanned much the Orion Arm of the Milky Way. The human empire collapsed centuries ago in a brutal civil war that wiped out the majority of the species. The descendants of distant human colonies are still around, so it is debatable whether or not they should be called "Precursors". However, because the ancient human homelands have long been lost, they are considered "extant", which leads many to consider them befitting of the term.