An amazing discovery was made by an 11-year-old girl in Tennessee, when she found a 475-million-year-old fossil dating back to the Paleozoic era.Ryleigh Taylor, 11, said she found the fossil as she was walking along the banks of Douglas Lake.To get confirmation, her family contacted Colin Sumrall, an associate professor of paleobiology at the University of Tennessee."It's actual fairly unusual for someone to find a fossil," Sumrall said.Sumrall said Ryleigh found a trilobite, an extinct marine arthropod that lived in water around east Tennessee millions of years ago.The lucky find is something Ryleigh's parents couldn't believe at first."I'm surprised that it was right on top of that rock, for anyone who could have found it," Tammy Taylor said. "But I'm very proud of her."Ryleigh hopes other children will get out and enjoy nature, so they can see what they can find."I can show kids that are my age that they don't have to sit inside and play games," she said. "They can actually go outside.""To find something like that, it could take this youngster into a whole career," Sumrall said. "Maybe she'll become a great paleontologist someday."