You asked a really good question. I asked a colleague of mine who did several seasons of fieldwork on upper paleolithic European archaeology and she helped me a bit.

Short answer, we can’t know for sure… especially since they originate at a time when we know modern humans were in Europe. The author of the paper runs with the notion that layers 3-11 were occupied by archaic humans, since they date to a time period when Neandertals existed in the area. Also, since Uluzzian tools have a closer affinity to Mousterian type tools, and less of a resemblance to the refined blades associated with modern humans, we have assumed that modern humans did not give up their advanced toolset for a more archaic form. But recent research has shown us that Neandertals are much more modern than we’ve given them credit for…

I am going to try and ask Julien Riel-Salvatore to see if he has a more definitive answer. I know of some other friends who have done fieldwork at sites like Atapuerca, maybe they’ve got some tidbits as well.

Thanks,

Kambiz