What Is This Domed Structure?

"We were about two and a half feet away from the deer, but we were not in it. We dedefin the dome structure itself," he says. "I couldn't figure for the life of me how the bone could have been left like that." 'It really didn't make a lot of sense,' she adds. "'If a hunter did this, why would he have left it here?' I remember grabbing a stick a we never crossed that fire cut'