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The Hadrosaurus foulkii was discovered in Haddonfield, New Jersey in 1838 by John Estaugh Hopkins while digging in a marl pit on his farm. In 1858, while summering in Haddonfield, William Parker Foulke, who worked at the Academy of Natural Sciences in Philadelphia, was given permission by Hopkins to begin an official dig at the site of discovery. The mounted skeleton went on display at the Academy of Natural Sciences ten years later. The Hadrosaurus was the first dinosaur skeleton complete enough to be mounted, so the novelty of this exhibit drew visitors from all over the world. The town of Haddonfield itself drew paleontologists interested in the dig site, including Edward Drinker Cope and Othniel Charles Marsh. A conflict developed between the two called the “Bone Wars”. This rivalry emphasizes Haddonfield’s importance to the developing field of paleontology. 


Statue in downtown Haddonfield of Haddy the Hadrosaurus which was a community project started by the Haddonfield Garden Club in 2003. It is made of bronze and was built by John Giannotti to commemorate the discovery of the dinosaur.

Plant, Extinction, Sculpture, Statue

Joseph Leidy pictured next to the femur bone from the Hadrosaurus in Haddonfield from the year 1858. At the time, Leidy was the chairman of the Board of Curators of Philadelphia's Academy of Natural Sciences.

Hair, Art, Beard, Collar

Hadrosaurus foulkii skeleton displayed at the Academy of Natural Sciences of Drexel University in Philadelphia, Pennsylvania. It was mounted in 1868, becoming the world's first mounted dinosaur for public display.

Extinction, Dinosaur, Rib, Organism

Front and back of the portrait of William Foulke, an associate of the Philadelphia Academy of the Natural Sciences. Dr. Joseph Leidy recognized the work of Foulke in naming the dinosaur Hadrosaurus foulkii.

Coat, Sleeve, Suit, Collar

Mr. John Estaugh Hopkins, the property owner of the marl pit on Maple Avenue, in Haddonfield, New Jersey, who discovered several bones of the Hadrosaurus foulkii.

Shirt, Beard, Tie, Jaw

Edward Drinker Cope, a paleontologist who discovered hundreds of different dinosaur species in the United States. He was one of the two important men involved in the "Bone Wars".

Forehead, Hair, Chin, Hairstyle

Othniel Charles Marsh, professor of vertebrate paleontology at Yale University, who undermined Edward Drinker Cope to claim numerous fossils found throughout the country, during the conflict known as the Bone Wars.

Forehead, Nose, Head, Chin

Hadrosaurus skeleton mounted at the Academy of Natural Sciences in 1868.

Photograph, White, Organism, Rib

Haddonfield Memorial High School period 5 APUSH and Hadrosaurus Statue

Shorts, Smile, Sky, Plant

The Hadrosaurus lived in North America until 65 million years ago when the Cretaceous–Paleogene extinction took place. This event was the meteor strike that caused the mass extinction of three-quarters of all species on Earth. Since New Jersey was underwater, the Hadrosaurus floated after its death through the sea and sank where Haddonfield would develop millions of years later. The bones of the Hadrosaurus and many other species were buried by sediment shortly after their death. These layers of sediment allowed the body to decompose leaving only the bones, teeth, and horns. 

In 1838, workers digging in a marl pit near Maple Avenue, Haddonfield, discovered some of the remains of an unknown creature. John Estaugh Hopkins owned a nearby estate, Birdwood, and hired workers to dig up local marl pits for profit. The marl, a kind of clay, would be sold and used as a fertilizer. When the workers came across the bones, they were unaware of the significance of their find. Some of the bones were brought home by the workers while others remained within the Birdwood estate. Twenty years later, when Dr. William Foulke visited Hopkins at his estate, Hopkins brought up the discovery. Dr. Foulke instantly recognized the significance of the bones and Hopkins allowed him to lead a dig of the marl pit in hopes of identifying the dinosaur. After the dinosaur was excavated, it was brought to the Academy of Natural Sciences by Dr. Joseph Leidy, a colleague of Foulke. He named it Hadrosaurus foulkii; “Hadrosaurus” meaning “bulky lizard” and “foulkii” for William Foulke, who had overseen its excavation. Leidy became the world’s first scientist to publish a pamphlet on the anatomy of a dinosaur. In 1868, it was finally mounted and put on display at the Academy of Natural Sciences, greatly increasing the number of visitors to the museum.

The discovery and exhibition of the Hadrosaurus increased the popularity of paleontology. Before the Hadrosaurus was found, very little was known about dinosaurs. Their existence was debated because nothing more than teeth had been discovered in North America. Once the Hadrosaurus remains were excavated, people marveled at the first nearly complete bone structure of a dinosaur. It disproved the theory that all dinosaurs walked on four legs, as the Hadrosaurus walked on two. The “Bone Wars” also showed the increased interest in paleontology. Othniel Marsh, a professor at Yale, traveled to Haddonfield after hearing about the paleontological discoveries being made. He met with fellow paleontologist, Edward Drinker Cope of the University of Pennsylvania, who had a monopoly on the bones discovered in town. When Marsh was brought to Cope’s dig site in 1877, he bribed the workers to send any fossils found there straight to him, rather than to Cope. Both were desperate to be the first to study and identify the bones. 

The Hadrosaurus’s significance continues up to the present. It became the official dinosaur of New Jersey in 1991 through the work of teacher Joyce Berry and her fourth-grade class at Strawbridge Elementary School in Haddon Township. A plaque was put up by boy scouts at the discovery site, which was added to the National Register of Historic Places in 1994. Almost 200 years after its discovery, the dinosaur is still a source of pride for the community of Haddonfield. It was affectionately nicknamed “Haddy”, and a statue was erected in downtown Haddonfield, at the intersection of Chestnut Street and Kings Highway, as a monument to its significance to the town.

Cunningham, John. "Bones Discovered Near Haddonfield Were First Major Dinosaur Find." The Haddon Gazette (Haddonfield) May 23rd 1963. , 8-8.

Clement, Tillie. "Haddonfield’s Hadrosaurus Story for National Magazine." The Haddon Gazette (Haddonfield) March 31st 1988. , 2-2.

"Haddonfield May Stake Another Claim, Dinosaur Bones May Become State Fossil." The Haddon Gazette (Haddonfield) January 4th 1990. , 1-2.

Hadrosaurus | Natural History Museum, Natural History Museum . Accessed June 1st 2021. https://www.nhm.ac.uk/discover/dino-directory/hadrosaurus.html.

Hadrosaurus.Com -- Official Haddonfield Dinosaur Committee Site, Official Web Site of the Haddonfield Dinosaur Sculpture Committee. Accessed June 1st 2021. http://hadrosaurus.com/1858.shtml.

Colbert, Edwin. A Hadrosaurian Dinosaur from New Jersey, JSTOR. Accessed June 1st 2021. https://www.jstor.org/stable/4064414?seq=1#metadata_info_tab_contents.

Glassman, Susan. Joseph Leidy and the "Great Inventory of Nature'', JSTOR. Accessed June 1st 2021. https://www.jstor.org/stable/4065003?seq=1#metadata_info_tab_contents.

Hadrosaurus Foulkii - the Academy of Natural Sciences of Drexel University, The Academy of Natural Sciences of Drexel University. Accessed June 1st 2021. https://ansp.org/exhibits/online-exhibits/stories/hadrosaurus-foulkii/.

History of the Town of Haddonfield, Historical Society of Haddonfield. Accessed June 1st 2021. https://haddonfieldhistory.org/about/history-of-the-town-of-haddonfield/.

Prieto-Marquez, Albert. The Dinosaur Hadrosaurus Foulkii, From the Campanian of the East Coast of North America, With a Reevaluation of the Genus, The Dinosaur Hadrosaurus Foulkii, From the Campanian of the East Coast of North America, With a Reevaluation of the Genus. Accessed June 1st 2021. app.pan.pl/archive/published/app51/app51-077.pdf.

First Dinosaur Skeleton Ever Mounted for Public Display, Finding the World's First Dinosaur Skeleton. Accessed June 1st 2021. https://www.levins.com/mount.shtml.

Haddonfield and the 'Bone Wars', Finding the World's First Dinosaur Skeleton. Accessed June 1st 2021. https://www.levins.com/bwars.shtml.

Hadrosaurus Foulkii: The Creature, Finding the World's First Dinosaur Skeleton. Accessed June 1st 2021. https://www.levins.com/creature.shtml.

"Local Fifth-Grader Wins Prize in Dinosaur Art Contest." The Haddon Gazette (Haddonfield) July 30th 1987. , 2-2.

Image Sources(Click to expand)

The Sun Newspapers

The Academy of Natural Sciences

The Academy of Natural Sciences

The American Philosophical Society

The Historical Society of Pennsylvania

Valley Forge National Historical Park, Pennsylvania

New World Encyclopedia

Official Web Site of the Haddonfield Dinosaur Sculpture Committee

Class of 2022