The Bursen, or Forerunner B, were an ancient spacefaring race who reached their peak around 198,000 BCE (reference stardate -2,000/00), during the period of history known to historians as the Forerunner Era. Imprints of their skin suggested a reptilian appearance. They were named after their discoverer, and known largely from fossil evidence.

The origin, homeworld and decline of the Bursen was completely unknown. The last was thought to have perished around 150,000 years before the 23rd century. (FASA RPG module: The Orions: Book of Common Knowledge)