Hadrosaurus (sturdy lizard) is an extinct genus of hadrosaurid dinosaur. In 1858, the only known skeleton was discovered, representing the first dinosaur species known from more than isolated teeth to be identified in North America. In 1868, it became the first ever mounted dinosaur skeleton. Hadrosaurs foulkii is the only species in this genus and has been the official state dinosaur of New Jersey, United States since 1991.
Description[]
Hadrosaurus lived in what is now North America, in the late Cretaceous period. It eat plants. It was likely bipedal for the purposes of running, but could use its forelegs to support itself while feeding—like all hadrosaurids, Hadrosaurus was herbivorous.
Discovery[]
In 1838, John Estaugh Hopkins was digging in a marl pit (on a small tributary of the Cooper River in Haddonfield, New Jersey, and part of the Campanian-age Woodbury Formation) when he uncovered large bones, putting them on display at his home, also in Haddonfield. In 1858 these bones sparked the interest of a visitor, William Parker Foulke. The skeleton was dug out from the marl pit in 1858 by Foulke. The excavation site, known as the Hadrosaurus Foulkii Leidy Site, is now a National Historic Landmark. Foulke contacted paleontologist Joseph Leidy, and together they recovered an almost complete set of limbs, along with a pelvis, several part of the feet, twenty-eight vertebrae (including eighteen from the tail), eight teeth and two small parts of the jaw. Foulke and Leidy studied the fossils together, and in 1858 Leidy formally described and named Hadrosaurus foulkii in honor of his collaborator.
Leidy recognized that these bones were from a dinosaur by their similarity to those of Iguanodon, discovered in England some decades before, but the skeleton of Hadrosaurus was far more complete. Leidy's monograph Cretaceous Reptiles of the United States, describing Hadrosaurus more completely and with illustrations, was written in 1860 but the American Civil War delayed its publication until 1865. Leidy reconstructed Hadrosaurus as a biped, in contrast to the view at the time that such dinosaurs were quadrupedal. The entire skeleton was completely assembled in 1868 by a team including English sculptor and naturalist Benjamin Waterhouse Hawkins and was put on display at Philadelphia Academy of Natural Sciences. The skeleton is usually kept 'behind-the-scenes' in the Academy's collections. However, from November 22, 2008 until April 19, 2009, a fully assembled cast of the skeleton and an exhibit about the science and culture surrounding the dinosaur's discovery was open to the public.
Despite the fact that the family Hadrosauridae has Hadrosaurus as its type genus, the skeleton lacks a skull and is too incomplete to compare to other hadrosaurines for classification purposes, leading most scientists to consider it a nomen dubium, or dubious name. When the skeleton was first assembled, it was displayed with a plaster skull sculpted by Hawkins. Many other artists have recreated Hadrosaurus with skulls from other, related species such as Gryposaurus and Brachylophosaurus. A statue of Hadrosaurus, sculpted by Haddonfield resident John Giannotti, now stands in the center of the town of Haddonfield, commemorating its discovery there.
Classification[]
Despite the fact that the family Hadrosauridae has Hadrosaurus as its type genus, the skeleton lacks a skull and was long viewed as too incomplete to compare to other hadrosaurs for classification purposes, leading most scientists to consider it a nomen dubium, or dubious name. However, a re-evaluation of the fossil material in 2011 noted several distinct characteristics of the skeleton that could allow the genus Hadrosaurus and species H. foulkii to remain in use as a valid taxon.
Hadrosaurus has also traditionally served as the basis for a large sub-family called Hadrosaurinae, which was seen as a group of largely crestless group of hadrosaurs related to the crested sub-family Lambeosaurinae. However, the changing view of Hadrosaurus classification in relation to other hadrosaurs has led some scientists to rename these subfamilies. In a 2008 study, Hadrosaurus was found to be more primitive than either lambeosaurines or other "hadrosaurines", and not a particularly close relative of classic "hadrosaurines" like Edmontosaurus and Saurolophus. As a result of this, the name Hadrosaurinae was restricted to Hadrosaurus alone, and the subfamily comprising the traditional "hadrosaurines" was renamed the Saurolophinae.
Below is a simplified cladogram recovered by Ramírez-Velasco et al. in 2012 in their description of Huehuecanauhtlus. This topology was recovered using an extensive sampling of sixty hadrosauroid species, and two outgroup taxa, which were scored based on 287 morphological traits,[9] and included data from two recent re-descriptions of Hadrosaurus by Prieto-Márquez et al. (2006) and Prieto-Márquez (2011).
| Hadrosauroidea |
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In Popular Culture[]
- In the DuckTales episode "Dinosaur Ducks" The Duckbilled Dinosaurs name Hadrosaurus was mentioned by Scrooge McDuck. But the Hadrosauruses had a longneck like a Sauropod Dinosaur.
- A Skeleton of Hadrosaurus appears in the 1st episode program of the 4 part PBS Documentary The Dinosaurs! The Monsters Emerge.
- Hadrosaurus was seen on Dinosaur Train. The most notable Hadrosaurus Hattie appeared on The 4 part special "Dinosaurs A to Z".
- Hadrosaurus appears in Michael Crichton's novel, "Jurassic Park".
- In Steven Spielberg's film rendition the Hadrosaurus was set to appear in both Jurassic Park and The Lost World, but was removed in the final production in interests for other unique dinosaurs and filming time.
Gallery[]
Hadrosaurus/Gallery