> Tyranids giant biological hive mind that rapidly adapts to new environments consuming or infecting existing species to plunder their genetic advantages. Also have plenty of units that looks rather similar to their Zerg equivalents.
Tyranids barely existed when Starcraft got released, most of the things you talked about was created by games workshop afterwards, so likely they copied Starcraft instead.
Tyranids where part of the 1987 version of 40k and barely mentioned. Genestealers were first introduced in the board game Space Hulk published in 1989 and introduced into the Tyranids well before Starcraft’s release date.
1993, featured the Tyranids in the supplemental books Wargear and Codex Imperialis, and then later in their own devoted army Codex.
By comparison Starcraft 1 is from 1998 at which point Tyranids had gone through multiple revisions and had fairly close to their modern lore.
Tyranids barely existed when Starcraft got released, most of the things you talked about was created by games workshop afterwards, so likely they copied Starcraft instead.