Unlike the fictional denizens of Jurassic Park, Hadrosaurus foulkii does not inspire terror. But when its fossil was dug up in 1858 in Camden County, it caused a sensation: it was the first virtually complete dinosaur fossil found in modern times.

Now, with interest in dinosaurs rekindled even as they fade deeper into history, the site of the discovery has been declared a national historic landmark.

The Haddonfield hadrosaur "really was of world importance," said John W. Bond, a Cherry Hill historian who wrote the designation proposal. "It revolutionized the way people thought of dinosaurs."

The fossil's path to fame started in summer 1858, when William Parker Foulke, a lawyer and member of the Academy of Natural Sciences in Philadelphia, was vacationing in Haddonfield. John Estaugh Hopkins, a prominent landowner, told Mr. Foulke about strange fossil bones found 20 years earlier on his farm. Although some had been carried off, Mr. Foulke was able to excavate a bonanza of jaw and rib fragments, back and tail vertebrae, a forelimb, hip structures and most of a hind leg.