Lack of evidence for Initial Upper Paleolithic attribution at Cueva Millán in Iberia’s hinterland

Sánchez-Yustos et al. 1 investigated lithic assemblage from Cueva Millán and propose its classification as a southern European manifestation of the Initial Upper Paleolithic (IUP, ~ 50–40 kya cal BP). This paper critically evaluates that classification against the IUP, a technocomplex whose foundational phase is the Early Emiran in the Levant 2 , defined by distinct blade technology with Levallois features and associated with Homo sapiens dispersal across Eurasia 3 , 4 . The Cueva Millán assemblage lacks diagnostic IUP technological markers and exhibits predominantly Middle Paleolithic (MP) features, including Levallois-based core reduction and MP tool types. Such misclassification risks conflating MP and IUP techno-cultural units, thereby obscuring our understanding of the Neanderthal-to- H. sapiens transition.