English: A clickable image of the en:Hadrosauroidea. Illustration by en:User:Debivort.

The en:Hadrosaurids comprise the dinosaurs commonly known as "duck-billed" dinosaurs. They were common herbivores during the en:Cretaceous period, and prey to en:therapods such as en:Tyrannosaurus. Spectacular fossils of hadrosaurs have been found, including mummified specimens in which soft tissue was preserved, skin impressions, tracks of footprints, and nest sites that demonstrate the animals had parental care of offspring. Animals are shown to scale.

A crisp diagram showing the evolutionary relationships between the tribes of the Hadrosauroidea, with representative individuals shown to scale. Conveys the diversity of the group. Every dinosaur shown has passed review for scientific accuracy at en:Wikipedia:WikiProject Dinosaurs/Image review.

The individual drawings are genera, and the branches of the tree go down to tribe. All these groups were alive in the late Cretaceous, and are generally known only from a single fossil site