Naashoibitosaurus by Moondawg

Naashoibitosaurus (meaning in Navajo na‘asho‘i "lizard creek") is a genus of hadrosaurid dinosaur that lived about 73 million years ago.

Naashoibitosaurus, based as it is on a single partial skeleton, is not well-known in terms of anatomy. Its skull, the most thoroughly described portion, has a low nasal crest that peaks in front of the eyes, but does not strongly arch as in Gryposaurus.

Naashoibitosaurus is a hadrosaurine hadrosaurid, a "flat-headed or solid-crested duckbill". It is closest to the solid-crested forms like Saurolophus. If it is the same as Kritosaurus, Kritosaurus would be used because it is the older name, but its position vis-a-vis other duckbills would be the same.

Befitting a genus with a confusing taxonomic history, the name of this genus is based on an error. David Gillette and David Thomas collected the type and only known specimen from what was thought to be the Naashoibito Member of the Kirtland Formation, the youngest member of the Kirtland; this was commemorated in the name. Instead, it came from the older, late Campanian-age De-na-zin Member. Horner described the skull in 1992 as that of an immature Kritosaurus, using it as evidence that Gryposaurus was different from Kritosaurus. At the same time, Hunt and Lucas were describing the postcrania as belonging to Edmontosaurus saskatchewanensis. When the disconnect became apparent, Hunt and Lucas gave the specimen its own generic name, because the skull did not agree with an edmontosaur, and they considered Kritosaurus indeterminate and thus not usable.