"Duckbill" is a vernacular term for Hadrosauridae, a large family of herbivorous dinosaurs, with many different species.
Hadrosauroids
Bactrosaurus
Cedrorestes
Eolambia
Gilmoreosaurus
Levnesovia
Protohadros
Tanius
Hadrosaurids (valid genera)
Amurosaurus
Anasazisaurus
Anatotitan
Angulomastacator
Aralosaurus
Arenysaurus
Barsboldia
Brachylophosaurus
Charonosaurus
Claosaurus
Corythosaurus
Edmonotosaurus
Gryposaurus
Hypacrosaurus
Hypsibema
Jaxartosaurus
Kerberosaurus
Koutalisaurus
Lambeosaurus
Lophorhothon
Maiasaura
Naashoibitosaurus
Nanningosaurus
Nipponosaurus
Olorotitan
Pararhabdodon
Parasaurolophus
Prosaurolophus
Sahaliyania
Saurolophus
Secernosaurus
Shantungosaurus
Telmatosaurus
Tethyshadros
Tsintaosaurus
Velafrons
Wulagasaurus
Zhuchengosaurus
Hadrosaurids (dubious genera)
Arstanosaurus
Cionodon
Diclonius
Hadrosaurus
Hypsibema
Mandschurosaurus
Microhadrosaurus
Orthomerus
Thespesius
Trachodon