Pteranodon
While the first "Pteranodon" wing bones were collected by Marsh and Cope in the early 1870s, the first "Pteranodon" skull was found on May 2, 1876, along the Smoky Hill River in Wallace County (now Logan County), Kansas, USA, by Samuel Wendell Williston, a fossil collector working for Marsh. A second, smaller skull soon was discovered as well. These skulls showed that the North American pterosaurs were different from any European species, in that they lacked teeth and had bony crests on their skulls. Marsh recognized this major difference, describing the specimens as "distinguished from all previously known genera of the order Pterosauria by the entire absence of teeth." Marsh recognized that this characteristic warranted a new genus, and he coined the name "Pteranodon" ("wing without tooth") in 1876. Marsh reclassified all the previously named North American species from "Pterodactylus" to "Pteranodon". He considered the smaller skull to belong to "Pteranodon occidentalis", based on its size. Marsh classified the larger skull, YPM 1117, in the new species "Pteranodon longiceps", which he thought to be a medium-sized species in between the small "P. occidentalis" and the large "P. ingens". Marsh also named several additional species: Pteranodon comptus and "Pteranodon nanus" were named for fragmentary skeletons of small individuals, while "Pteranodon gracilis" was based on a wing bone that he mistook for a pelvic bone. He soon realized his mistake, and re-classified that specimen again into a separate genus, which he named "Nyctosaurus". "P, nanus" was also later recognized as a "Nyctosaurus" specimen.
Rhamphinion
The type species, "Rhamphinion jenkinsi", was described and named in 1984 by Kevin Padian, based on holotype MNA V 4500, a partial skull including the occipital region, a partial left jugal, a fragment of the lower jaw including two preserved teeth and the impression of a third, and one other fragment that could not be identified. The specific name honors the discoverer of the fossil, Farish Alston Jenkins Jr. At the time, it was the oldest known pterosaur specimen from the Western Hemisphere (now overtaken by "Caelestiventus"). Padian did not assign it to any family or suborder within Pterosauria, but did note that the jugal was unlike that of pterodactyloids, and so may have belonged to a "rhamphorhynchoid", i.e. a basal pterosaur. A bone from the wing of another pterosaur from the same formation, found in 1981, may have also belonged to a "rhamphorhynchoid", with a wingspan of about 1.5 m (4.9 ft). Peter Wellnhofer agreed that a "rhamphorhynchoid" identity was very likely, but David Unwin was more hesitant to classify its fragmentary remains in "The Pterosaurs: From Deep Time," noting it only as a "possibly valid species of uncertain relationships." A recent cladistic analysis of "Jidapterus" recovers "Rhamphinion" as a close relative of "Dimorphodon" and "Parapsicephalus".