Pteranodon
Pteranodon (; from Greek πτερόν ( pteron, "wing") and ἀνόδων (anodon, "toothless") is a genus of pterosaur that included some of the largest known flying reptiles, with wingspans over 8 meters (26 feet). They lived during the late Cretaceous geological period of North America in present-day Kansas, Alabama, Nebraska, Wyoming, and South Dakota. More fossil specimens of "Pteranodon" have been found than any other pterosaur, with about 1,200 specimens known to science, many of them well preserved with nearly complete skulls and articulated skeletons. It was an important part of the animal community in the Western Interior Seaway.
Eilenodon
"Eilenodon robustus" is the type species of Eilenodontinae, a subfamily of Opisthodontia. It and other eilenodonts had very wide and strongly packed teeth as well as a deep jaw for chewing and shredding plant material. It is primarily known from an incomplete pair of lower jaws approximately 5 centimeters (2 inches) long. If the jaws were complete, they would have been about 10 centimeters (4 inches) long, signifying that "Eilenodon robustus" was among the largest species of rhynchocephalians known, surpassed only by its fellow eilenodont "Priosphenodon avelasi". Among all other sphenodonts, "Eilenodon" is most similar to "Toxolophosaurus", another eilenodont which was redescribed the same year as "Eilenodon's" description. Even so, there are some differences between the two taxa.