The New Jersey Hadrosaurus, 1858
The teeth identified by Joseph Leidy in 1856 were valid but scanty evidence of North American dinosaurs. Much more dramatic evidence was forthcoming in 1858, when several large limb bones, numerous vertebrae, some jaw fragments, and a few teeth were discovered at Haddonfield, New Jersey, and presented to the Academy of Natural Sciences in Philadelphia. Leidy recognized the fossils as belonging to a dinosaur like Iguanodon, and he named it Hadrosaurus foulkii, after the discoverer and benefactor. More remarkably, Leidy noted the disparity between the long hind legs and the short front legs and concluded: "The great disproportion of size between the fore and back parts of the skeleton of Hadrosaurus, leads me to suspect that this great extinct herbivorous lizard may have been in the habit of browsing, sustaining itself, kangaroo-like, in an erect position on its back extremities and tail." This is the first suggestion anywhere that some dinosaurs might have been, at least on occasion, bipedal.
Leidy's 1858 paper was not illustrated, but in 1865 he published a large monograph that did contain a fairly complete series of plates depicting most of the hadrosaur bones. Around 1868, Benjamin Waterhouse Hawkins made a restoration of the skeleton for the Academy of Natural Sciences.
The Hadrosaurus Bones, 1865
In 1865 Joseph Leidy published a sizable monograph on extinct Cretaceous reptiles whose remains had been found in the United States. Most of the specimens he discussed were preserved in the Academy of Natural Sciences in Philadelphia. The featured specimen, in terms of number of plates, was Hadrosaurus foulkii. On a series of large lithographs, Leidy presents the vertebrae, limb bones, and teeth of his prize find. This was the first time that Hadrosaurus had been illustrated in print. The illustration reproduced here is a large folding plate that shows six views of the left femur of Hadrosaurus, as well as two views of a metatarsal bone, which may or may not have come from the same animal.
Hawkins' Restoration of Hadrosaurus, 1868 [1904]
In 1868 Benjamin Waterhouse Hawkins undertook a skeletal restoration of Leidy's Hadrosaurus, as part of an ill fated project to erect in New York's Central Park a counterpart to the Sydenham Park dinosaur tableau. Most of Hawkins' American restorations were destroyed, but the Hadrosaurus skeleton apparently survived and was on display at the Academy of Natural Sciences in Philadelphia for many years.
There are a few archival photographs of the skeleton that survive, and they have been reproduced in several recent secondary sources. But these photographs were not published at the time, so it is difficult to find an image in the contemporary literature. The best we have been able to uncover is this photograph that appeared in Frederick Lucas's article on the 1903 restoration of Trachodon. Lucas wanted to show what previous restorations looked like, and so he provided the reader with a nice full page photograph of Leidy's Hadrosaurus.