The Philadelphia naturalist and polymath Joseph Leidy, who named the Hadrosaurus, noted that, “this great herbivorous Lizard sustained itself in a semi-erect position… while it browsed on plants.” To Leidy, Hadrosaurus was less a reptilian rhino and more like a kangaroo., The image of the dinosaur became that of an active creature who stood upright instead of slithering on the ground. The skeleton of the Hadrosaurus helped to create a more up-to-date model of the dinosaurs. The English artist and sculptor Benjamin Waterhouse Hawkins constructed a version for Philadelphia’s Academy of Natural Sciences that stood about 30 feet in length.