Hadrosaurus

Hadrosaurus was a genus of Hadrosaurid dinosaurs that lived in the late Cretaceous Period. It was described in 1858 by Joseph Leidy in Haddonfield, New Jersey. It's skull was never discovered, so it's head shape is debatable, whether it looked like that of Kritosaurus, which lived at the same time and place, or like that of later hadrosaurids, such as Edmontosaurus or Parasaurolophus.