Hadrosaurus

Hadrosaurus is a valid genus of hadrosaurid dinosaur. In 1858, the only known skeleton was discovered, representing the first dinosaur species known from more than isolated teeth to be identified in North America. In 1868, it became the first ever mounted dinosaur skeleton. Hadrosaurus foulkii is the only species in this genus and has been the official state dinosaur of New Jersey, United States since 1991.

Hadrosaurus foulkii is known from a single specimen consisting of much of the skeleton and parts of the skull. The specimen was collected from the Woodbury Formation in New Jersey, USA. Using radio isotope dating of bivalve shells from the same formation, the sedimentary rocks that the Hadrosaurus fossil was found in were formed at some point between 80.5 and 78.5 million years ago.