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.
Paleontology in the United States
By the beginning of the 19th century, their fossil footprints definitely had been found in Massachusetts and later, Connecticut. These tracks were researched by the Reverend Edward Hitchcock and instrumental to the establishment of ichnology, the study of trace fossils, as a science. During the late 1850s, the world's first reasonably complete dinosaur skeleton was discovered in New Jersey. Joseph Leidy would name it Hadrosaurus. This was the first known dinosaur, the first dinosaur to be interpreted as two-legged, and the first to be mounted for exhibition in a museum. Later in the century Edward Drinker Cope described a new carnivorous dinosaur from New Jersey he called Laelaps. When he gave fellow paleontologist Othniel Charles Marsh a tour of the quarry the fossils were taken from Marsh secretly convinced Cope's workers to send fossils to himself instead. Marsh also learned that the name Laelaps had already been used for a different animal and renamed Cope's dinosaur Dryptosaurus out from under him. This instigated a bitter rivalry to collect the most fossils and name the most new prehistoric species that took the two paleontologists and their crews deep into the west looking for fossils and attempting to undermine each other's fieldwork.