[4] They were mostly replaced by the larger azhdarchids at the end of the Late Cretaceous however, which resulted in resource and terrain competitions, but even so, pteranodontoids still managed to thrive with them, and genera such as Alcione, Barbaridactylus, and Simurghia lived until the Cretaceous-Paleogene extinction event.

They were also known for their proportionally large wingspans, the largest recorded of any pteranodontoid reached 8.70 meters (28.5 ft), and it belongs to the genus Tropeognathus.

British paleontologist James Scott Bowerbank named and described the specimens found as a new species of Pterodactylus, P. giganteus due to its much larger size.

[8] Later that year, British paleontologist Sir Richard Owen had also unearthed several fossil specimens in the Chalk Formation, in which he assigned them as Pterodactylus compressirostris during its description.

With the naming of this new species, British paleontologist Harry Govier Seeley created a new separate genus called Ornithocheirus (from Ancient Greek "ὄρνις", meaning "bird", and "χεῖρ", meaning "hand"), due to the notion of the time, in which pterosaurs were the direct ancestors of birds.

In the United States, American paleontologist Othniel Charles Marsh led an expedition to the Smoky Hill Chalk deposits in western Kansas in 1870.

[15] In 1871, he assigned these specimens to a new species called "Pterodactylus oweni" (meaning "Owen's wing finger"),[16] in honor of Sir Richard Owen, but he realized that the name he had chosen had already been used for a different European pterosaur species described by Harry Seeley, so he renamed his discovery as Pterodactylus occidentalis (meaning "Western wing finger"), in reference to the location where it was found.

[17] American paleontologist Edward Drinker Cope had also unearthed several remains of the large North American pterosaur, and based on these remains, Cope named two new species, Ornithochirus umbrosus and Ornithochirus harpyia, in an attempt to assign them to the large European genus Ornithocheirus, but he had missed the 'e' when describing them.

[25][26] In 1913, English paleontologist Reginald Walter Hooley reviewed O. latidens in detail, based on specimens he had found, and placed the genus Ornithodesmus within a newly created family, Ornithodesmidae.

[27][28] Later in 1993, the British paleontologists Stafford C. Howse and Andrew C. Milner concluded that the holotype sacrum and only specimen of the species O. cluniculus didn't belong to a pterosaur, but instead to a maniraptoran theropod dinosaur.

[29] Later that year, David Unwin suggested a different definition, the node that contains Pteranodon longiceps and Istiodactylus latidens, as a resulting, he considered Pteranodontoidea a junior synonym of Ornithocheiroidea.

[3] In 2013, Andres & Timothy Myers presented a phylogenetic analysis that placed Pteranodontoidea within the group Pteranodontia, as the sister taxon of the family Nyctosauridae.

[30] In 2019 however, Kellner and colleagues revisited the classification, and concluded that Pteranodontoidea, which was sister taxon to Tapejaroidea, would be the more inclusive group containing both the Lanceodontia and the Pteranodontia.

Aetodactylus halli Cearadactylus atrox Brasileodactylus araripensis Ludodactylus sibbicki Anhangueridae Ornithocheiridae Topology 2: Kellner and colleagues (2019).

[31] Dsungaripteridae Azhdarchoidea Pteranodon longiceps Tethydraco regalis Nyctosaurus gracilis Muzquizopteryx coahuilensis Hongshanopterus lacustris Nurhachius ignaciobritoi Istiodactylus latidens Istiodactylus sinensis Haopterus gracilis Lonchodraco giganteus Ikrandraco avatar Ornithocheirus simus Cimoliopterus cuvieri Anhangueria