possibly even dinosaurs one source "The Mysterious Origin and Supply of Oil" "The Mysterious Origin and Supply of Oil" "The Mysterious Origin and Supply of Oil" "The Mysterious Origin and Supply of Oil" "The Mysterious Origin and Supply of Oil" The Mysterious Origin And Supply Of Oil fuel economy "The Mysterious Origin and Supply of Oil" probably originated from plant material long and complex process "The Mysterious Origin and Supply of Oil" livescience.com one source