Slimak now argues the Châtelperronians were actually a second wave of modern humans into Europe. Massive, 1.2 million-year-old tool workshop in Ethiopia made by 'clever' group of unknown human relatives Bering Land Bridge was only passable during 2 brief windows, study finds Unknown lineage of ice age Europeans discovered in genetic study However, scientists had often thought Châtelperronians were Neanderthals. In addition, Châtelperronian items date to about 45,000 years ago, or between those of the Neronians and the Protoaurignacians. Stone artifacts from a European industry known as the Châtelperronian highly resemble modern human artifacts seen in the Early Upper Paleolithic of the Levant. This led him to look for possible modern human counterparts of these artifacts in Europe. In addition, Slimak found thousands of modern human flint artifacts from the Levant that existed in the period known as the Early Upper Paleolithic, between the Ksar Akil and the Ahmarian ones. 'I buil a bridge between Europe and the East Mediterranean populations during the early migrations of sapiens in the continent,' Slimak said. The much younger Protoaurignacian artifacts also have very similar counterparts in the Levant from a culture known as the Ahmarian, Slimak noted. This suggested both groups were one and the same, with the Levantine group expanding into Europe over time.

When Slimak compared Neronian tools from Grotte Mandrin with the industry from about the same time from a site known as Ksar Akil in Lebanon, he found notable similarities.

Scientists have long thought that the Levant was a key gateway for modern humans migrating out of Africa. Slimak focused on a group or 'industry' of stone artifacts previously unearthed in the Levant, the eastern Mediterranean region that today includes Israel, Palestine, Jordan, Lebanon and Syria.

Sapiens yuval