Hadrosaurus is a genus of hadrosaurid ornithopod dinosaurs that lived in North America during the Late Cretaceous Period in what is now the Woodbury Formation about 78-80 Ma. The holotype specimen was found in fluvial marine sedimentation, meaning that the corpse of the animal was transported by a river and washed out to sea.
Hadrosaurus
Benjamin Waterhouse Hawkins' mounted Hadrosaurus, the first mounted dinosaur skeleton in the world
Photograph of the site where the fossils were found (2010)
Plates from Leidy's description
Hadrosaurids, or duck-billed dinosaurs, are members of the ornithischian family Hadrosauridae. This group is known as the duck-billed dinosaurs for the flat duck-bill appearance of the bones in their snouts. The ornithopod family, which includes genera such as Edmontosaurus and Parasaurolophus, was a common group of herbivores during the Late Cretaceous Period. Hadrosaurids are descendants of the Late Jurassic/Early Cretaceous iguanodontian dinosaurs and had a similar body layout. Hadrosaurs were among the most dominant herbivores during the Late Cretaceous in Asia and North America, and during the close of the Cretaceous several lineages dispersed into Europe, Africa, and South America.
Hadrosauridae
Illustration of Trachodon mirabilis teeth
From the mid 19th century through much of the 20th century, hadrosaurs were considered aquatic animals which subsisted on soft water plants
Skeleton of Maiasaura posed with a nest; the naming of this genus was one of numerous important developments in the Dinosaur Renaissance