Most people driving down Mantua Pike in Gloucester County have no idea they are passing over a literal graveyard of the Cretaceous period. It's an old marl pit. Honestly, it looks like a giant hole in the ground from the road. But this isn't just any hole. This is the Jean and Ric Edelman Fossil Park and Museum, and it represents one of the most significant paleontological sites on the entire East Coast.
Forget the dusty, velvet-roped galleries you're used to in big cities.
This place is built directly into a 65-million-year-old mystery. While most museums ship their bones in from Montana or China, the dinosaur museum Sewell NJ has become famous for is actually sitting on the very dirt where these creatures died. Specifically, it’s located at the precise layer of the Earth that marks the mass extinction of the dinosaurs.
The Mantua Bend: A 65-Million-Year-Old Crime Scene
The site is a former Inversand marl quarry. For decades, workers here were digging up greensand to use as fertilizer and water softener, but they kept hitting "junk." That junk turned out to be the skeletal remains of mosasaurs, crocodiles, and sea turtles.
Dr. Kenneth Lacovara is the man you need to know here. He’s the world-renowned paleontologist who discovered Dreadnoughtus in Patagonia, and he’s the founding executive director of this park. He describes the site as a "time capsule."
The geology here is unique. Unlike the American West, where fossils are often scattered by millions of years of river movement, the fossils in Sewell are found in a concentrated bone bed. They’re basically 40 feet below the current ground level. It’s a snapshot of the moment the asteroid hit the Yucatan Peninsula. Because New Jersey was underwater at the time—basically a shallow subtropical sea—the animals that died here settled into the soft mud and stayed there.
It’s messy. It’s gritty. You will get mud under your fingernails.
What You'll Actually See in the Museum
The museum building itself is a $75 million marvel of sustainable architecture. It’s "Net Zero," meaning it produces as much energy as it uses. But you aren't going for the solar panels. You're going for the Dinosarium.
✨ Don't miss: Getting Around the City: How to Actually Read the New York Public Transportation Map Without Losing Your Mind
Inside, the exhibits don't just show skeletons; they show the ecosystem. You’ll see the Thoracosaurus, a terrifying ancient crocodile that lived right here in Gloucester County. There are also reconstructions of Dryptosaurus, New Jersey’s own "tearing lizard." Fun fact: Dryptosaurus was actually the first leaping predatory dinosaur ever depicted in art, way back in the 19th century.
The Hall of Cretaceous Seas is a highlight. Imagine a 50-foot mosasaur—a marine lizard with a double-hinged jaw and a second set of teeth in its throat—swimming right over your head. It’s terrifying. It’s basically the T-Rex of the ocean.
Digging in the Dirt: The Public Experience
The real draw of the dinosaur museum Sewell NJ offers is the chance to actually participate. This isn't a simulation.
During "Community Dig" days, the park opens up the pits to the public. You get a trowel. You get a brush. You get a spot in the marl.
People find real shark teeth. They find Exogyra (fossilized oysters that look like giant cinnamon rolls). Sometimes, a lucky kid finds a vertebrae from a Mosasaur. Because there is so much material, the museum actually lets visitors keep certain common fossils. It’s a wild feeling to hold something in your hand that hasn't seen the sun in 65 million years.
One thing to keep in mind: it’s hot in the pits during the summer. There is no shade in a quarry. Bring water. Lots of it.
Why the Location Matters
Why Sewell? It seems like an odd spot for a world-class research facility.
🔗 Read more: Garden City Weather SC: What Locals Know That Tourists Usually Miss
The marl found here, known as the Hornerstown Formation, is remarkably good at preserving bone. The sediment is fine-grained and low in oxygen, which prevented the bones from decaying or being scavenged before they could fossilize.
The site was nearly lost to history. A decade ago, it was slated to be a shopping center or an apartment complex. Rowan University stepped in, backed by a massive $25 million donation from alumni Jean and Ric Edelman, to preserve the land for science.
Misconceptions About Jersey Dinosaurs
A lot of folks think dinosaurs only lived in the desert. Wrong.
During the Late Cretaceous, New Jersey was the "Jersey Shore" of the dinosaur world, but the coastline was much further inland. Sewell was essentially the beachfront property of the era. You wouldn't have found a T-Rex here—that was a western species—but you would have found its cousins.
- Size isn't everything: While we didn't have the massive sauropods of the West, our marine fossils are world-class.
- It’s not just "old bones": The museum uses augmented reality to show how these creatures moved.
- It’s a working lab: You can watch researchers through glass partitions as they clean fossils found just feet away.
The research coming out of this park is helping scientists understand how ecosystems collapse and recover. By studying the "extinction layer" in the quarry, Dr. Lacovara and his team are looking for clues about our own climate future.
Planning Your Visit
If you’re heading to the dinosaur museum Sewell NJ, you need to book early.
The park operates on a timed-entry system to ensure the dig pits don't get overcrowded. It’s located at 122 Woodbury-Glassboro Rd, Sewell, NJ 08080. If you’re coming from Philly, it’s a quick 20-minute jump over the bridge. From New York, it’s about an hour and a half.
💡 You might also like: Full Moon San Diego CA: Why You’re Looking at the Wrong Spots
Dress like you’re going for a hike, not a gala. The marl is a greenish-grey clay that stains clothes. If it rained the night before, the pits will be a swamp. Embrace it. That’s where the best fossils are usually hiding anyway.
Taking Action: How to Make the Most of the Fossil Park
To get the most out of your trip to the Jean and Ric Edelman Fossil Park, follow these specific steps:
Check the Event Calendar Constantly
Public dig days sell out in minutes. They usually announce them on the Rowan University website or the museum's official social media channels months in advance. Set an alert.
Bring the Right Gear
While the museum provides basic tools for public digs, having your own small soft-bristled paintbrush and a magnifying glass can make the experience much more rewarding for kids.
Learn the "Big Three" Fossils
Before you go, show your kids what a shark tooth (Cretalamna), a brachiopod, and a squid beak (Belemnitella) look like. These are the most common finds. Being able to identify them in the mud makes the "hunt" feel successful immediately.
Visit the Research Gallery First
Go inside the museum before you hit the pits. Seeing the fully assembled skeletons gives you the scale you need to realize that the "weird rock" you just found might actually be a piece of a prehistoric predator’s rib cage.
Support the Science
The park is a non-profit venture. If you find something truly significant—like a limb bone or a rare tooth—you won't be able to keep it. It goes into the research collection to be studied by paleontologists. Don't be bummed; your name might end up in a scientific paper as the person who discovered it.