Pteranodon
Pteranodon (; from Greek πτερόν ( pteron, "wing") and ἀνόδων (anodon, "toothless") is a genus of pterosaur that included some of the largest known flying reptiles, with wingspans over 8 meters (26 feet). They lived during the late Cretaceous geological period of North America in present-day Kansas, Alabama, Nebraska, Wyoming, and South Dakota. More fossil specimens of "Pteranodon" have been found than any other pterosaur, with about 1,200 specimens known to science, many of them well preserved with nearly complete skulls and articulated skeletons. It was an important part of the animal community in the Western Interior Seaway.
Cimoliornis
In 1842, James Scott Bowerbank re-examined the remains and concluded that they actually belonged to a pterosaur, based on the microstructure of the bones, and estimated that it would have had a wingspan of about . By modern standards, the remains are too fragmentary to calculate a reliable wingspan estimate, but "Cimoliornis diomedeus" was undoubtedly the largest known pterosaur until the 1857 discovery of larger "Ornithocheirus" species.