The Fett, or Forerunner A, were an ancient spacefaring race native to the Alpha or the Beta Quadrant, who reached their peak around 398,000 BCE (reference stardate -4,000/00), during the period of history known to historians as the Forerunner Era. They were a chitinous species, perhaps resembling Earth's lobsters. They were named after their discoverer, and known largely from fossil evidence. (FASA RPG module: The Orions: Book of Common Knowledge)

By the description and time-frame, the Fett could be the Siri.