[3] William Parker Foulke, an attorney and amateur paleontologist affiliated with Philadelphia's Academy of Natural Sciences, was vacationing in Haddonfield in 1858, when he was alerted to the discovery in 1838 of large bones on the farm of Joseph Hopkins.

Foulke proceeded to direct a careful excavation in the area surrounding Hopkins' marl pit, turning the finds over to Dr. Joseph Leidy for analysis.

[4] Foulke unearthed 35 of an estimated 80 bones from the Hadrosaurus, which is believed to have been herbivorous, 7 meters in length, and weigh 2.5 tons.

[5] Leidy published an analysis in 1865, and oversaw the creation of a reconstructed skeleton of the creature found in 1868.

[4] The site lingered in obscurity until 1984 when a local Boy Scout from Troop 65, Christopher Brees, as part of an Eagle Scout project researched the site and generated publicity, eventually leading to the species being designated the official dinosaur of New Jersey.