| Noun | 1. | suborder Ornithopoda - widespread group including duck-billed dinosaurs and their early relatives (hadrosaurs, trachodon and iguanodon) animal order - the order of animals order Ornithischia, Ornithischia - extinct terrestrial reptiles having bird-like pelvises: armored dinosaurs (thyreophorans); boneheaded and horned dinosaurs (marginocephalians); duck-billed dinosaurs (euronithopods) ornithopod, ornithopod dinosaur - bipedal herbivorous dinosaur family Hadrosauridae, Hadrosauridae - duck-billed dinosaurs; upper Cretaceous genus Trachodon - a reptile genus of the suborder Euronithopoda family Iguanodontidae, Iguanodontidae - iguanodons |