Mudge discovered Ichthyornis in 1872. While he initially planned to ship the specimen to Cope, he heard of Othniel Charles Marsh's interest and sent it instead to his former acquaintance from Connecticut. Marsh first described the bird in 1872, but misidentified the toothed jaw as belonging to a type of lizard. Marsh associated the jaw with the avian postcranial elements and published the new data the next year. An analysis in 1952 concluded the jaw actually belonged to a mosasaur,Gregory, 1952 but a reevaluation in 1967 and new specimens confirmed Marsh's assessment.
