A teen was searching for arrowheads in southern Iowa when he unearthed a 34,000-year-old jawbone from a mastodon.
The 30-inch bone, found last week, is from a juvenile mastodon that might have stood 7 feet tall, the Iowa City Press-Citizen reports.
Researchers with the University of Iowa Paleontology Repository now have possession of the bone.
The family who found it wanted to remain anonymous to keep people from trespassing on their farm in search of more fossils.
The Associated Press contributed to this report.
