Sixty six million years after it witnessed the end of the Cretaceous Period and the mass extinction event that wiped out the dinosaurs, a sprawling area of marl pits in Mantua Township, Gloucester County, New Jersey is once again alive with Cretaceous life — or at least impressive representations of it. Opened in March of 2025, the Edelman Fossil Park & Museum of Rowan University is a visual wonder of science and entertainment celebrating Southern New Jersey’s unique role as one of the world’s most important discovery venues in the history of paleontology. (Photos: Hoag Levins)
Although a few of Dryptosaurus’ skeletal parts were originally discovered in 1886 in Mantua Township marl deposits, its full morphology and identification as a relative of the T-Rex family wasn’t finally established until a century later. It was one of the first meat-eating dinosaurs known to science — largely as a result of the huge and horrific claw found the initial 1866 dig.
What is now southern New Jersey was once the bottom of a shallow sea whose bottom is now the marl deposits where fossils of prehistoric creatures are entombed. One of the most ferocious was Mosasaurus, a whale-sized reptile that was an apex predator of the Cretaceous seas. Visitors to the museum walk through a building that sits atop a marl deposit from which fossils of these sea giants have been extracted.
Ornithomimus — the name means “bird mimic” — is a from a group often referred to as “ostrich dinosaurs” because of their striking resemblance to modern flightless birds. These were 12 feet long and six feet tall or larger and had powerful legs designed for running, likely reaching speeds up to 40 mph or more. That speed was a primary defense against the Dryptosaursuses and other carnivorous dinosaurs they lived amongst.
Although often called “flying dinosaurs,” Pterosaurs like this Pteranodon were actually flying reptiles. Their wingspan was comparable to, or even larger than, some of the largest birds that have ever lived and absolutely dwarf any bird living today. For instance, today’s largest is the Albatross with a wingspan of 11 feet. But Pteranodon had a wingspan of 21 feet. And, though often described as “leathery,” Pterosaurs were actually covered in soft, hair-like filaments .
One of the largest and most dramatic displays in the Edelman Museum is that of the fanged and clawed carnivorous predator Acrocanthosaurus and the colossal vegetarian Astrodon locked in fight-to-the-death combat. The winner — Astrodon — is in the process of breaking the Acrocanthosaurus’ neck. The initial 1858 discovery near Muirkirk, Maryland, of what later became known as Astrodon, included only two teeth. The full morphology of the beast wasn’t established until more than a century later. The first Acrocanthosaurus fossil was discovered in 1941 in Oklahoma.
The fossil that the Philadelphia Academy of Natural Sciences hailed as “The Dinosaur that Changed the World” is Hadrosaurus foulkii excavated in 1858 from a marl pit in Haddonfield, NJ. It was the first nearly-complete dinosaur skeleton found anywhere in the world. In 1868, it also became the first dinosaur fossil mounted for public display in a Museum anywhere in the world. That specimen generated enormous scientific interest, triggering the “Bone Wars” or feud between Edward Drinker Cope and Othniel Charles March to discover more dinosaur fossils in New Jersey’s marl and then across the continent.
From 1925 to 2015 the marl pit on which the Edelman Museum is located was the site of the Inversand Company that mined the marl, extracting mineral compounds that were crucial for the water softening industry. Its workers routinely encountered fossils like this 66-milion-year-old shark’s tooth. I took this photo of the company’s marl mining operations in 2003.
On weekends, Inversand’s site was a popular spot for local fossil hunters who dug its pit or sieved the huge tailing piles produced by the industrial surface mining operations. I was one of these amateur fossil hunters who used portable screening devices to process large amount of marl mining tailings to find various kinds of fossils.
Today, outside its main building, the Edelman Museum offers visitors the “Quarry Dig Experience” enabling them to dig and search for prehistoric fossils in the marl pit where mosasaurs, marine crocodiles, sea turtles and sharks have previously been unearthed by scientists and other fossil hunters.
After pulling up various items of potential interest, Quarry Dig Experience visitors are provided an area where they can clean and examine their specimens — a process shown here being done with toothbrushes. They can match them against visual charts of known fossil types and consult with Edelman staffers who help them identify and understand their finds.
In a glass-walled section of the basement of the Museum, paleontologists and staffers continue their groundbreaking research and cataloguing of fossil finds, allowing visitors to observe the scientific work that is happening in parallel with their own discoveries.
Over the last century, more than 100,00 Cretaceous fossils from more than 100 species have been excavated from the quarry. According to the Museum, it is the only place in the world where you can see a preserved fossil ecosystem from the exact moment of the asteroid impact that marked the end of the dinosaurs.
Aside from the life-sized reproductions of prehistoric animal scenes throughout the museum, the facility also includes plenty of fossil bone displays.
This is a nearly six-foot-high femur or thigh bone from a Dreadnoughtus Schrani, one of the largest dinosaurs so far known. The fossil was discovered in 2005 in a remote part of southern Argentina and excavated over four years by a team led by Edelman Fossil Park & Museum Executive Director Dr. Kennth Lacovara.
Beyond its cafe and gift shop, the Edelman Museum also offers a Science Lounge in its basement with a wide range of exhibits aimed at educating children and interested adults in a wide variety of scientific subjects.
Outside is one of the southern New Jersey’s most unique playgrounds called Pterosaur Pterrace dominated by a wooden Pterosaur that serves as a massive jungle gym of the prehistoric kind.
