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).
Pterygotus
The first fossils of "Pterygotus" were found in deposits of Lochkovian-Pragian (Early Devonian) age by quarrymen in Scotland and western England, who referred to the large fossil remains as "Seraphims". Louis Agassiz, a Swiss-American biologist and geologist, described the fossils in 1839 and named it "Pterygotus" in the belief that they were the fossil remains of a large fish; ""Pterygotus"" translating to "winged fish". The specimens described by Agassiz from England were referred to a species he dubbed "Pterygotus problematicus". Agassiz first recognized the true nature of the fossils as arthropod remains five years later in 1844 after having examined more complete fossils recovered in the Old Red Sandstone of Scotland. Although recognizing the fossils of "Pterygotus" as arthropod was closer to its modern phylogenetical position, Agassiz would consider "Pterygotus" to represent a crustacean of the Entomostraca subclass. Although Frederick M'Coy did note that "Pterygotus" resembled the Limulidae and the previously discovered eurypterid "Eurypterus" in 1849, he classified both "Eurypterus" and "Pterygotus" as crustaceans.