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.
Eurypterid
Giant eurypterids were not limited to the Pterygotidae family. An isolated long fossil metastoma of the carcinosomatoid eurypterid "Carcinosoma punctatum" indicates the animal would have reached a length of in life, rivalling the pterygotids in size. Another giant was "Pentecopterus decorahensis", a primitive carcinosomatoid, which is estimated to have reached lengths of .