CANBERRA, AUSTRALIA—Discovered in a dry lake bed in southeastern Australia in 1970, the 43,000-year-old skeleton known as Mungo Man is the oldest known Australian. Since being found, his remains have been kept at Australian National University, and they are no longer being studied. Now Aboriginal groups are negotiating with officials for the return of the remains to Lake Mungo National Park, where they would be reunited with the 20,000-year-old skeleton dubbed Mungo Lady who was uncovered not far from Mungo Man. “This discovery changed Australian history, but Mungo Man has spent too long in his cardboard box. He needs to go home,” archaeologist Jim Bowler told The Australian.