Pteranodon, the "Toothless Wing," is a very well-known genus of pterosaur due to a lot of representation in both the fossil record and several popular movies and television shows. Showing a great degree of sexual dimorphism, Pteranodon is a fascinating prehistoric flying reptile. Males grew to over six meters from wingtip to wingtip and had a very large crest; females were smaller with wingspans that didn't quite reach four meters and shorter, rounder crests. Though traditionally the crest was thought to be used as a rudder when flying, the range of sizes of crests across the sexes means it likely was not used for anything other than mating displays. During the late Cretaceous Period, the center of the United States was an underwater paradise known as the Western Interior Seaway, which was a small sea full of tasty creatures for Pteranodon to feast on. Its diet likely consisted of only fish, but at least there were plenty of fish in the sea for every pterosaur. Pteranodon probably fished by sitting on the water and plunging their long beaks into the waves, but may have also been able to dive into the water to make spectacular catches. On land, these creatures walked on all-fours with their wings folded so that their small hands could reach the ground.