How large was the Pteranodon?
Pteranodon
Williston was also the first scientist to critically evaluate all of the pteranodont species classified by Cope and Marsh. He agreed with most of Marsh's classification, with a few exceptions. First, he did not believe that P. ingens and P. umbrosus could be considered synonyms, which even Cope had come to believe. He considered both P. velox and P. longiceps to be dubious; the first was based on non-diagnostic fragments, and the second, though known from a complete skull, probably belonged to one of the other, previously-named species. In 1903, Williston revisited the question of Pteranodon classification, and revised his earlier conclusion that there were seven species down to just three. He considered both P. comptus and P. nanus to be specimens of Nyctosaurus, and divided the others into small (P. velox), medium (P. occidentalis), and large species (P. ingens), based primarily on the shape of their upper arm bones. He thought P. longiceps, the only one known from a skull, could be a synonym of either P. velox or P. occidentalis, based on its size.[6]