In 1970, Amos Flora of Flora, Indiana, discovered teeth and jawbones while dredging a creek. Scientists discovered that the bones were from a mastodon and that they had lost 77.2% of their carbon-14. How old were the bones at the time that they were discovered? (Sources: "Farm Yields Bones Thousands of Years Old," by Dan Mc Feely, Indianapolis Star, October 20, 2008; Field Museum of Chicago, Bill Turnbull, anthropologist)