Hadrosaurus is a genus of duck-billed dinosaur that lived during the Late Cretaceous period, approximately 75 million years ago. It was primarily herbivorous and is known for its distinctive flat, broad snout, which resembled that of a duck. Hadrosaurus could grow up to 30 feet long and walked both on two legs and four, allowing it to adapt to different environments. Fossils of Hadrosaurus were first discovered in North America, particularly in what is now New Jersey. This dinosaur is significant in paleontology as it was one of the first to be recognized as a distinct species, helping to advance the study of dinosaur classification and evolution.