Timing of the emergence of the Europe–Sicily bridge (40–17 cal ka BP) and its implications for the spread of modern humans

The submerged sill in the Strait of Messina, which is located today at a minimum depthof 81 m below sea level (bsl), represents the only land connection between Sicily and mainlandItaly (and thus Europe) during the last lowstand when the sea level locally stood at about 126 mbsl. Today, the sea crossing to Sicily, although it is less than 4 km at the narrowest point, faceshazardous sea conditions, made famous by the myth of Scylla and Charybdis. Through a multidisciplinaryresearch project, we document the timing and mode of emergence of this land connectionduring the last 40 kyr. The integrated analysis takes into consideration morphobathymetric andlithological data, and relative sea-level change (both isostatic and tectonic), resulting in the hypothesisthat a continental land bridge lasted for at least 500 years between 21.5 and 20 cal ka BP. Theemergence may have occurred over an even longer time span if one allows for seafloor erosion bymarine currents that have lowered the seabed since the Last Glacial Maximum (LGM). Modellingof palaeotidal velocities shows that sea crossings when sea level was lower than present would havefaced even stronger and more hazardous sea currents than today, supporting the hypothesis that earliesthuman entry into Sicily most probably took place on foot during the period when the sillemerged as dry land. This hypothesis is compared with an analysis of Pleistocene vertebratefaunas in Sicily and mainland Italy, including a new radiocarbon date on bone collagen of anEquus hydruntinus specimen from Grotta di San Teodoro (23–21 cal ka BP), the dispersal abilitiesof the various animal species involved, particularly their swimming abilities, and the Palaeolithicarchaeological record, all of which support the hypothesis of a relatively late land-based colonizationof Sicily by Homo sapiens.