In practice, animals like Callovosaurus, Camptosaurus,
Craspedodon, Kangnasaurus, Mochlodon, Muttaburrasaurus, Ouranosaurus, and Probactrosaurus were usually assigned to this family.
At one point, Jack Horner suggested, based mostly on skull features, that hadrosaurids actually formed two more distantly related groups,
with Iguanodon on the line to the flat-headed hadrosaurines, and Ouranosaurus on the line to the crested lambeosaurines, but his proposal has been rejected.
Scientific Expedition Room Ligabue- Dedicated to the scientific expedition of the archaeologist Giancarlo Ligabue in Niger(Sahara Gadoufaoua) in 1972-1973,
he presents many precious finds including the skeleton of a dinosaur Ouranosaurus nigeriensis, considered one of the most interesting finds in the world of this type.