Digging at the site has previously revealed remains of Hadrosaurus, a duck-billed, plant-eating dinosaur, but no eggs have ever been found there,
And instead of the broad, flat head that now sits atop the skeleton, Gallagher said recent research has led him to believe that Hadrosaurus'skull was narrower.
Many other artists have recreated " Hadrosaurus " with skulls from other, related species such as " Gryposaurus " and " Brachylophosaurus ".
Working with the scientist Joseph Leidy, Hawkins designed and cast an almost complete skeleton of Hadrosaurus foulkii which was then displayed at the Academy of Natural Sciences in Philadelphia.
More recently, on September 29, 1991, Governor James Florio signed a bill declaring " Hadrosaurus foulkii " to be the state dinosaur of New Jersey.
When the current display of skeletal casts was installed in the New Jersey Museum in the 1930s, the Hadrosaurus had already been a has-been for half a century.
A statue of " Hadrosaurus ", sculpted by Haddonfield resident John Giannotti, now stands in the center of the town of Haddonfield, commemorating its discovery there.
In 2010, the subfamily Saurolophinae was brought back into use because " Hadrosaurus " appears to have branched off prior to the " hadrosaurine " lambeosaurine split.
The year after the " Hadrosaurus "'s fossils were first identified, 1865 Joseph Leidy formally named the species " Astrodon johnstoni " after Christopher Johnston.
Although the fragile fossilized remains are stored at the Academy of Natural Sciences in Philadelphia, reproductions of Hadrosaurus foulkii can be seen on display there and at the State Museum in Trenton.