Proto-Italic or proto-Latin aren't recognized at the moment, those will be in the future. Proto-indo-european PIE languages will be recognized as a mixture defined from BOTH central asian migrations westward toward the coast AS WELL AS migrations inland from the continental shelves during sea level rise. We do not currently have the sedimentary artifacts we need from ~150 meters below modern sea level to clearly demonstrate this, but, we will. Perhaps not during my life nor yours, but some 100 or more years in the future we certainly must as the delta sediments are explored more fully. Many ancient structures will be discovered on the continental shelves prior to structures like stone-henge, which were constructed on high plateaus which are now not far above sea shore.