Yaxkin biovirus was a biological weapon developed by Yaxkin. The people did not know about warfare or how they fought, but they knew about advanced biotechnological weapons. They unleashed a bioweapon that killed the enemy and who later mutated and killed locals. Those elders of the people left a message in inskrivit in a building about the incident and that the virus died out with them the last of the people. (SG1: "City of the Gods")