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.
Ctenospondylus
Species were about three meters (ten feet) long. The genus is known only from the 'Seymouran' Land Vertebrate Faunachron, which is equivalent to the upper part of the Artinskian stage and the lowermost Kungurian stage of the Early Permian. Its fossils were found in the U.S. states of Ohio and Texas. It was a carnivore and preyed upon animals close to its size. "Ctenospondylus" had a long tail, short back spines, and a very deep yet narrow skull with massive jaws that had sharp teeth. Because of its large size, it was probably the apex predator in its environment, and might have competed with other predators like "Dimetrodon" for food. A sphenacodontid, it was a close relative of "Dimetrodon".