Pteranodon was a huge flying reptile with a wingspan of over 20 feet. It belonged to an extinct group of reptiles called pterosaurs. Pterosaurs were not dinosaurs, but were closely related. Pteranodon lived during the Cretaceous Period, about 86 million years ago in what is now western North America. Although Pteranodon and other pterosaurs resembled modern bats, they were not related.
The first Pteranodon specimen was found in 1870 in Kansas by Othniel Marsh, the famous paleontologist from Yale University. Marsh recognized that it was a pterosaur, but it had no head, so he wasn’t sure whether it was the same as the pterosaurs from Europe, or something new. A few years later, in 1876, some skulls were found, showing that Pteranodon was indeed completely different from any known pterosaur.