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.
Patranomodon
The skull fossil of "Patranomodon" was found in the "Eodicynodon" Assemblage Zone of South Africa, belonging to the lowest biozone of the Beaufort Group. The Beaufort Group time period extends from the middle of the Permian to the early Triassic era. It is one of the three main subdivisions of the Karoo Supergroup in what today is southern Africa. Rubidge and Hopson were the first to discover the skull of "Patranomodon". These paleobiologists also named "Patranomodon" and were the first to publish literature on it starting in 1990. The most abundant remains of "Patranomodon" were found on the Eastern Cape of South Africa; however, fossil parts were also found in Europe, China, as well as India, which indicated migration occurring among these terrestrial creatures. The paleontologist Nyaphuli collected the fossil of this creature in South Africa and gave it the species name of ""Patranomodon nyaphuli"".
"Patranomodon" have a short exposure of their palatine and premaxilla, which creates a shorter face compared to other anomodontons. This gives "Patranomodon" a shorter facial structure, shorter in length as well as small in size. They also have a reduced tabular, a slit-like interpterygoid vacuity, three sacral vertebrae, and a screw-shape jaw. The genus has many features indicating its herbivorous behavior: the division of the external adductor muscles in the jaw into two separate components, the medial and lateral side, as well as using a propalinal jaw movement while feeding on plant material.