 The majority of evidence for the Two Layer Hypothesis consists of dental and morphometric analyses from archaeological sites throughout Southeast Asia, most prominently Thailand and Vietnam.The credibility of the Two Layer Hypothesis has been criticized due mainly to similarities between Southeast Asian and Chinese cranial and dental characteristics, excluding Australo-Melanesians.The first fossilized skeletal remains and indication of early 'Proto-Australian' Southeast Asian inhabitants surfaced in 1920 during an excavation by Dubois on the island of Java.