Did you know that New Jersey has its own state fossil? Yes, you read that right! And even better, it’s a dinosaur!
A Rutgers student Ria Sarkar published an article about New Jersey’s State Fossil: Hadrosaurus foulkii for the Mastodon Musings.
A member of the Hadrosauridae subfamily and closely related to Iguanodontids, the Hadrosaurus foulkii was the first mostly complete dinosaur skeleton ever found in North America. It was the significant moment in the field of vertebrate paleontology in the late 1800s.
The name Hadrosaurus translates to “heavy lizard” or “bulky lizard” in Greek and the species name foulkii was named for the discoverer, William Parker Foulke. These dinosaurs first appeared about 100 million years ago during the Middle Cretaceous Period and are considered to be one of the most successful herbivorous groups at the end of the Cretaceous. And it’s not like their geographic distribution was exclusive to North America. Hadrosaurus were found in all continents, even Antarctica!
In the late 1830s, the Hadrosaurus was found by a farmer named John Estaugh Hopkins while he was digging in Haddonfield and started to uncover large bones. In 1858, Hopkins showed the bones to his friend William Parker Foulke, who decided to begin an excavation of the area with Joseph Leidy. They retrieved a nearly complete dinosaur skeleton with only the skull missing, measured the femur at an astonishing length of four feet and estimated that Hadrosaurus foulkii must have been at least 25 feet long.
Marveling at the sheer size of this creature, Leidy believed this was a dinosaur very similar to the recently discovered Iguanodon. Noting the orientation of the pelvis, Leidy believed this new specimen was bipedal with an upright posture, unlike the sprawling posture of Iguanodon. Scientists now believe that Hadrosaurus was a facultative biped, meaning that it normally walked on four legs, but could also walk on its two hind legs when necessary.
The Hadrosaurus is a genus of the Hadrosaurid dinosaurs, known as duck-billed dinosaurs for their mouths that resemble toothless beaks, with incredibly strong jaws and hundreds of teeth arranged in intricate “dental batteries” adapted to grind fibrous plants. Since the skeletons of most hadrosaurid species lack variation, their skulls are primarily used to distinguish between them. For example, some hadrosaurids had large bony crests on the top of their heads. The head crests function as an air reserve to allow the dinosaur to stay underwater. In addition to the duck-like beak and possible webbed feet (which later turned out to be impressions left by soft tissue), this idea of an air reserve led to the belief that Hadrosaurus was a marine animal. However, scientists now agree that Hadrosaurus was a terrestrial animal and that the head crest was primarily used to make low-frequency calls for long distance communication.
While the original skeleton of Hadrosaurus foulkii is mounted at Drexel University’s Academy of Natural Sciences, the Rutgers University Geology Museum also has a display dedicated to the beloved state dinosaur. Our Hadrosaur display contains a 19th century painting by a New Jersey resident and wildlife illustrator Robert Bruce Horsfall (1869-1948). His painting depicts a pair of Hadrosaurs roaming a marsh-like habitat. The posture of the Hadrosaurs is true to the early beliefs that the Hadrosaurus was bipedal and dragged its tail on the ground as it walked. However, modern reconstructions suggest that Hadrosaurus held its body in a more horizontal position with the tail held out for balance. Notice that the ankle bone, or astragalus, of a Hadrosaurus can distribute the weight of the body to the rest of the foot.
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