The Utah state archaeologist has determined the age of three mystery skulls mailed to Brigham Young University.
KSL-TV reports the skulls were determined to be from about 1100 to 1300 A.D.
That fits with the early suspicions of investigators that the skulls might be ancient artifacts.
The skulls will be turned over to Utah's Native American leaders.
The skulls were delivered to BYU's history department last month in a box labeled with a Montana return address.
University police say they don't know why the skulls were sent to BYU.
2010. "Archaeologist finds mystery skulls mailed to Brigham Young University are prehistoric". . Posted: Available online: http://www.google.com/hostednews/canadianpress/article/ALeqM5jSwcAUvDgvDksPfcAXQl_490Ooqw?docId=5043520