When a Hadrosaurus surfaced in a marl pit in the early 1800s, these massive bones made up the most complete dinosaur skeleton in the world. Like all Hadrosauridae, the Hadrosaurus had a mouth shaped like a duck’s bill. This plant-eater is only known from one fossil, but paleontologists have learned much about it in the past 150 years!
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Some Quick Facts About the Hadrosaurus
| Name | Hadrosaurus foulkii (meaning “Sturdy lizard”) |
| Type of dinosaur | Ornithopoda hadrosaurid dinosauria |
| Territory | Swampy and warm forest of North America |
| Size | Medium dinos, 23-26 feet long, 10-13 feet tall |
| Color | Olive brown on top, cream on the bottom |
| Interesting Characteristics | Duck-billed dinosaur with a small head |
| Diet | Herbivore |
| Major Threats | Climate disasters and carnivores |
The Hadrosaurus was an amazing duck-billed dinosaur discovered in the early 1800s in New Jersey. A Hadrosaur skeleton called “Haddy” was the first dinosaur skeleton ever to be publicly displayed! The discovery of the Hadrosaurus was so important that the Hadrosaurus was named the official state dinosaur of New Jersey.
What was Special About the Hadrosaurus?
The Hadrosaurus was part of the subfamily Hadrosaurinae. These Hadrosaurines are duck-billed dinosaurs without crests. (Hadrosaurids with crests are called Lambeosaurines).
In 2008, all Hadrosaurinae except Hadrosaurus were moved to the subfamily Saurolophinae. This subfamily still contains the crestless Hadrosaurs. Some crestless Hadrosaurs are:
For now, paleontologists consider the Hadrosaurus more primitive than other crestless species. Once more information is available, the Hadrosaurus might be regrouped with other crestless Hadrosaurs again. No matter where it falls on the family tree, it is still related to other Hadrosaurs.
What were the Hadrosaurus’ most distinctive features?
The Hadrosaurus was bulky, with thick back legs and a wide tail. Compared to other Hadrosaur femurs and bones, Hadrosaurus’s bones were much larger. The Greek translation of Hadrosaurus foulkii is “Foulke’s big lizard.”
At first, paleontologists thought the Hadrosaurus always walked on all four legs. Joseph Leidy studied the bones and decided that the Hadrosaurus was bipedal. About 150 years later, we know that the Hadrosaurs and other Ornithopods carried weight on their hind legs but walked on both 2 and 4 legs.
What Ate the Hadrosaurus?
A T-rex was the most common predator when the Hadrosaurus was alive. The T-rex was known to prey on other Late Cretaceous Hadrosaurs like Parasaurolophus and Lambeosaurus. Other carnivores and predators would’ve eaten the Hadrosaurus as well.
Like all Hadrosaurs, the Hadrosaurus probably lived in large herds with other herbivores. A Triceratops was a popular herd mate due to its three horns and ability to topple the T-rex. The Hadrosaurs weren’t good at fighting, but they knew they could find safety in the numbers and presence of other dinos.
When and Where Did the Hadrosaurus Live?
The only Hadrosaurus known to paleontologists lived between 80-78 million years ago. The skeleton of the Hadrosaurus was found in Haddonfield, New Jersey, in 1838. In 1858 William Parker Foulke dug the fossil up.
The Hadrosaurus foulkii was named in honor of Foulke by paleontologist Joseph Leidy. New Jersey was under the sea during the Hadrosaurus’ lifetime, so no other fossils exist. Other Hadrosauruses lived later into the Late Cretaceous period, but we won’t know until more fossils are found.
The discovery of the skeleton of Hadrosaurus was one of the most exciting breakthroughs at the time. Hopefully, paleontologists find more Hadrosaurus fossils to learn about this fascinating dino. Until then, the original Hadrosaurus called Haddy is on permanent display at the Academy of Natural Sciences in Philadelphia, where Haddy was first shared with the public!