Fossil preparator James Holstein stands next to a 244-million-year-old fossil in a research area of the Field Museum in Chicago.  He discovered the fossil, the Thalattoarchon Saurophagis, during an exploration with paleontologists in a remote mountain range in Central Nevada. The creature was a marine reptile that roamed the sea as a predator that lived at the same time as dinosaurs. At foreground is its vertebra. At top is its skull.