The origin of the Chaos Emeralds remains a mystery. The arrival of the green Chaos Emeralds on Mobius came thousands of years after the Xorda attacked the planet with Gene Bombs, which resulted in billions of tons of ash being hurled into the air, blocking out the sunlight. Nearly 2,000 years later, the sun finally broke through the dirt and ash. Around this period in time, the first primitive species on, the Mobosaurs, emerged. However, the green Chaos Emeralds mysteriously rained down on the planet, causing disastrous weather anomalies which wiped out all of the Mobosaurs with the exception of the Ancient Walkers and Mammoth Mogul, who had become demi-god like figures as a result of the Chaos Emeralds' powers. (StH: #148, TMS: #3, SMM)