Hadrosaurid

Hadrosaurids Fossil range: Late Cretaceous
Telmatosaurus, a basal hadrosaurid dinosaur.
Scientific classification
Class	Sauropsida
Superorder	Dinosauria
Order	Ornithischia
Suborder	Cerapoda
Infraorder	Ornithopoda
Superfamily	Hadrosauroidea
Family	Hadrosauridae Cope, 1869
Subfamilies	Hadrosaurinae Cope, 1869 Lambeosaurinae Parks, 1923
Synonyms	Trachodontidae Lydekker, 1888 Saurolophidae Brown, 1914 Lambeosauridae Parks, 1923 vide Horner, 1990

Hadrosaurids or duck-billed dinosaurs are members of the family Hadrosauridae, and include ornithopods such as Edmontosaurus and Parasaurolophus. They were common herbivores in the Upper Cretaceous Period of what are now Asia, Europe and North America. They are descendants of the Upper Jurassic/Lower Cretaceous iguanodontian dinosaurs and had similar body layout. They were ornithischians.

Hadrosaurids are divided into two subfamilies. The lambeosaurines (Lambeosaurinae) have large cranial crests or tubes, and are less bulky. The hadrosaurines (Hadrosaurinae) lack the cranial crests or tubes and are larger.