A study published in the journal Science is challenging beliefs about Tyrannosaurus rex and other dinosaurs considered theropods. By comparing skull and tooth size, the scientists believe T. rex had scaly lips that covered their impressively sharp teeth. The skeleton of one of these iconic predators is going up for auction in Switzerland. Someone who wants their own personal Jurassic Park is expected to spend anywhere from $5.4 to $8.7 million to buy the skeleton at auction.