Earliest human remains in Eurasia: New 40Ar/39Ar dating of the Dmanisi hominid-bearing levels, Georgia

Several hominid remains have been discovered in the open-air site of Dmanisi (Georgia), the oldest prehistoric site in Eurasia. Two major arguments prove that this site is close in age to the Plio-Pleistocene boundary: a Villafranchian fauna and the morphological characteristics of hominid remains recently ascribed to Homo georgicus. Direct dating of the lower hominid-bearing level was carried out on volcanic glass and minerals using the 40Ar/39Ar method. The concordant results from two different sampled locations allow the determination of the age of the earliest human presence in Eurasia. This radioisotopic result strengthens the argument that the first dispersal of hominids outside Africa occurred at least 1.8 Ma ago.