Pteranodon
"Pteranodon" was the first pterosaur found outside of Europe. Its fossils first were found by Othniel Charles Marsh in 1870, in the Late Cretaceous Smoky Hill Chalk deposits of western Kansas. These chalk beds were deposited at the bottom of what was once the Western Interior Seaway, a large shallow sea over what now is the midsection of the North American continent. These first specimens, YPM 1160 and YPM 1161, consisted of partial wing bones, as well as a tooth from the prehistoric fish "Xiphactinus", which Marsh mistakenly believed to belong to this new pterosaur (all known pterosaurs up to that point had teeth). In 1871, Marsh named the find ""Pterodactylus oweni"", assigning it to the well-known (but much smaller) European genus "Pterodactylus". Marsh also collected more wing bones of the large pterosaur in 1871. Realizing that the name he had chosen had already been used for Harry Seeley's European pterosaur species "Pterodactylus oweni" in 1864, Marsh re-named his giant North American pterosaur Pterodactylus occidentalis, meaning "Western wing finger," in his 1872 description of the new specimen. He also named two additional species, based on size differences: Pterodactylus ingens (the largest specimen so far), and Pterodactylus velox (the smallest).
Paleontology in Maryland
In 1859, state agricultural chemist Philip T. Tyson discovered the first dinosaur fossils of the Arundel Formation in an iron pit at Bladensburg, Prince George's County. The discovery consisted of two Early Cretaceous fossil teeth. Around the same time Tyson also discovered the Arundel Formation's first known fossil cycad trunks.[84] Tyson took the dinosaur teeth to a local doctor named Christopher Johnston. Johnston cut thin sections of one tooth to examine it under a microscope. He published a paper titled "Note Upon Odontography" in the American Journal of Dental Science. Johnson named the teeth "Astrodon". In 1865 Joseph Leidy formally named the species "Astrodon johnstoni" after Christopher Johnston. This represents the first formal naming of a sauropod species in North America.