The Volcanic Calamity
Extinction
~ 3651 BH - 2651 BH
A cataclysmic volcanic event during this time period caused mass extinction as far as we understand it.
This event has been debated by historians to be both natural and caused due to some form of divine intervention. Either way the event led to mass extinctions of both humanoids and animals alike during this time about 5000-6000 years ago. The event itself is believed to essentially be the simultaneous eruption of all of the world's volcanoes.