The Stone Age was a prehistoric event on Irk, similar to the same one on Earth.
Irkens have always been hunters. The beginning of civilization on Irk started around its equator, on a large island where wild exoskeletal beasts were plentiful, but hard to kill, while beasts with internal skeletons were also plentiful but easy to kill. Irkens showed the first signs of intelligence by using a sharpened piece of rock to cut through a beast's exoskeleton and internal skeleton. The Irkens soon after developed tools and built shelters, setting up the first Irken villages. The invention of the boat allowed Irkens to move away from their island and onto mainland. Other primitive Irken species already existed here (such as the Wolf-boar and Hogulus), but upon the arrival of the more advanced Irkens, they were believed to have been slaughtered mercilessly. However, this is not the case, as several of these beasts can still be seen walking around Irk to this day, outside of the main city.