When you walk on the Atlantic Coastal Plain, you are walking on soil that may have been high up in the mountains millions of years ago. As the sediments are buried deeper and deeper, they may be pressed into sedimentary rocks the best type for preserving fossils. The rocks of the Coastal Plain date mostly to the Cenozoic Era, or Age of Mammals. Any fossils found here would represent animals and plants that lived after the dinosaurs became extinct. As you walk inland from the sea, the fossils become older, and you may stumble over a dinosaur fossil from the Cretaceous Period.
New Jersey produces more dinosaur fossils than any other state in the eastern United States.
Many of the dinosaur remains found in New Jersey are of hadrosaurs. The Ellisdale fossil site was discovered in 1980. It is located on the Coastal Plain near Trenton. Fossils at this site date back between 68 and 74 million years to the late Cretaceous Period. Both land and marine animals lived here.