 A decade-long campaign by a Haddon Township teacher led to the selection of Hadrosaurus foulkii as the official state fossil in June 1991.This example of the dinosaur was excavated in 1858 from a marl pit near Haddonfield as one of the most complete dinosaur skeletons to be reconstructed.It remains on display at the New Jersey State Museum, where it has been on display since 1931.