The earliest inhabitants of the polar regions were the Neanderthals, or "Homo neanderthalensis", who are considered to be an intermediate stage between "Homo erectus" and "Homo sapiens sapiens". The Neanderthals made advances in the basic production of stone, bone antler and flint tools, which archaeologists call a Mousterian industry. About 40,000 years ago, the Neanderthals quickly disappeared and were replaced by modern humans, "Homo sapiens sapiens". Just a few thousand years after the sudden disappearance of the Neanderthals, modern humans occupied all the land that their predecessors had occupied. Some scientists believe that the Neanderthals were overcome by the incoming modern race, commonly called Cro-Magnon people, while others believe the race disappeared by integrating itself within the new population.