New horizons on the knowledge of the population during the Middle/Late Pleistocene. The human remains of Guattari Cave (S. Felice Circeo, Lt, Italy)

Along the coast of southern Lazio (central Tyrrhenian Sea) there is a significant series of multilayered coastal caves, most of which provide abundant evidence of occupation during the Neanderthal time horizon. In one of these caves, Guattari cave an extraordinary discovery of hominin remains dating back to approximately 66-65ka was made in 2019-2022, which places the Guattari cave finds in a specific period within the Neanderthal population of the Italian peninsula. Ongoing studies have demonstrated the presence of a particular morpho-anatomical variability in the population that lived in the Circeo area with plesio- and apomorphic characteristics that could open new evolutionary horizons. Biological variability and affinities that would suggest rather complex unexpected population dispersal scenarios. The particularity of these finds, chronologically very close, allows us to consider Guattari cave as one of the most important sites for the study of the Mediterranean area during the middle and late Pleistocene. We have studied the new finds and the morphology, compared to Circeo1 skull, aligns more with Javanese H. erectus than with Neanderthals. A discovery that identifies this region as a focal point of coexistence of different lineages, H. erectus s.s ., H. erectus s.l., proto-Neanderthal , "classical" Neanderthal , and H. sapiens , which could define new and unexpected migratory and evolutionary dynamics towards modern humanity. In a Neanderthal context, such as that of Circeo, the presence of fossil human evidence documenting a mosaic model consisting of a Javanese H. erectus paleodeme associated with primitive and unusual characters could represent the result of a hybridization between archaic and modern humans and a phenomenon of dispersal into Southeast Asia and Australo-Melanesian.