About 20 fragments were found, including a skull, rib sections, vertebra, a front leg bone and a kneecap, all believed to come from the same mastodonArchaeologists in Iowa have uncovered parts of a mastodon fossil, including its skull, that they believe dates back to when the first humans lived on Earth. Over the course of a 12-day excavation, staff from the University of Iowa's Office of the State Archaeologist worked with local community members to recover the bones. About 20 fragments were found, including a skull, rib sections, vertebra, a front leg bone and a kneecap, all believed to come...