Hadrosaurus foulkii 1858
In 1858, William Parker Foulke (2) was on vacation near Haddonfield, New Jersey when he heard stories of giant bones unearthed from a nearby farm 20 years earlier. No one knew the whereabouts of these bones, but Foulke did learn where they were dug up. He quickly obtained permission from the owner and employed a team to excavate the site. Foulke's team found seashells and sharks teeth. They also found the bones of an impressively large land animal. Foulke informed Joseph Leidy in nearby Philadelphia of his find.
The fossils Leidy examined consisted of a relatively complete set of front and hind limbs, a pelvis, part of a foot, 28 vertebrae, eight teeth and two jaw fragments. The teeth were similar to those of Iguanadon, a dinosaur discovered in England a couple of decades earlier.
Leidy knew he was looking at a dinosaur. More importantly, he was looking at the most complete dinosaur skeleton then known. Leidy named the dinosaur Hadrosaurus foulkii and first described it in December 1858 (3). He provided a more detailed description and a series of illustrations of Hadrosaurus in Cretaceous Reptiles of the United States, a monograph written in 1860, but not published until after the end of the Civil War in 1865.
Comparision
of corresonding bones from the front limb (radius; top) and hind limb (tibia;
bottom) of Hadrosaurus foulkii. These bones are details from two different
lithographs published in Cretaceous Reptiles of the United States (1865). Click on the bones to view the respective lithographs.One of the first of the giant's features to impress Leidy was that its hind limb was much larger than its fore limb. He wrote:
"The great disproportion of the size between the fore and back parts of the skeleton of Hadrosaurus lead me to suspect that this giant extinct herbivorous lizard may have been in the habit of browsing, substaining itself kangaroo-like in an erect position on its back extremities and tail".
Leidy's conclusion that Hadrosaurus was bipedal (standing on two feet) differed from that of the Richard Owen, the world's leading authority on dinosaurs. Owen reconstructed the English dinosaurs (Hylaeosaurus, Iguanodon, and Megalosaurus) as rhinoceros-like quadrapeds (standing on four feet) (4). Leidy's proposal of bipedal dinosaurs (based on substantially more complete fossil evidence) was met with opposition by some European scientists, but was embraced by others (5).
Hip bones of Hadrosaurus foulkii. The curved bone at the top is the ilium. The longer bone at the bottom is the ischium. These bones are details from two different lithographs in Cretaceous Reptiles of the United States (1865). Click on the bones to view the respective lithographs.
Leidy differed with Owen in another important respect. Owen had identified a long, thin bone in Iguanodon as a clavicle (collarbone). Leidy identified a similar bone in Hadrosaurus as part of the pelvis (hip). He also considered the Iguanodon bone to be part of the pelvis.
Teeth and jaw fragment of Hadrosaurus foulkii. The fossil on the far left is an unworn tooth. Next to it is a heavily worn tooth. The center figure shows a dental battery consisting of worn teeth at the top and unworn repacement teeth at the bottom. A jaw fragment with grooves for holding the teeth is shown to the right. These fossils are details from a lithograph published in Cretaceous Reptiles of the United States (1865). Click here or on the fossils to view the full lithograph.
Leidy noted that the teeth of Hadrosaurus were similar to those of the English Iguanodon and very similar to those of an American dinosaur (Trachodon mirabilis) he described in 1856. Leidy concluded that Hadrosaurus used its teeth to masticate (chew) its food rather than simply plucking it as do most plant-eating reptiles. He arranged the teeth in dental batteries with active teeth at the grinding surface and replacement teeth below (6).
Selected vertebrae from Hadrosaurus foulkii. These fossils are details from a lithograph published in Cretaceous Reptiles of the United States (1865). Click here or on the fossils to view the full lithograph.
The Hadrosaurus fossil had a total of 28 vertebrae. Three of these were cervical (neck bones), seven were dorsal (backbones) and eighteen were caudal (tailbones). Leidy noted that the vertebrae —unlike the teeth— bore little resemblence to those of Iguanodon. Although most ot the vertebrae were missing, Leidy's estimate of the dinosaur's length was reasonably close to the 30 ft (9 m) generally accepted today.
The importance of Hadrosaurus was obvious to Benjamin Waterhouse Hawkins. This British sculptor was famous for his life-sized scuptures of Owen's dinosaurs at the Crystal Palace near London. He had plans for similar, but updated scuptures in New York City's Central Park.
Hawkins offered to mount the Hadrosaurus skeleton at The Academy of Natural Sciences at no charge (7). The skeletal mount —the first mounted dinosaur in the world— was completed in 1868 and became an immediate sensation. Hawkins soon received orders for copies from Princeton, Chicago and the Smithsonian (8). (The mount and its creator are shown to the right.)
Websites:
- Hoag Levin's extensive web
site about the discovery of Hadrosaurus:
www.levins.com/hadrosaurus.html
Notes:
- Etymology:
Hadrosaurus (HAD-row-SAUR-us) = heavy or bulky lizard
foulkii (FOLK-ee-eye) = named in honor of W. P. Foulke
[go back] - W.
P. Foulke was a member and benefactor of The Academy of Natural Sciences of Philadelphia.
[go back] - Proceedings
of The Academy of Natural Sciences of Philadelphia, vol. 10 (1858), pp. 215-218.
[go back] - Gidion A. Mantell, who was
the first to describe Iguanodon, noted that its forelimbs of were shorter
than its hind limbs, but his observations were discounted by his rival, Richard
Owen. It was Owen's view of Iguanodon as a quadraped that prevailed.
Owen's reconstructions were influenced by politics. He opposed the idea of evolution. As commonly phrased by many of Owen's contempories, evolution was suppose to lead to improved or advanced animals, but his dinosaurs (which looked suspiciously like large mammals) were clearly more "advanced" than the "degenerate" modern-day reptiles. Owen believed that these magnificant creatures could only have been the result of divine creation.
[go back] - Whether
dinosaurs were bipedal or quadrapedal was debated for years. On major reason why
the debate continued is that some dinosaurs were bipedal (for example, Allosaurus,
Troodon and Tyrannosaurus), some were quadrapedal (Hyaelosaurus, Apatosaurus, Stegosaurus and Triceratops), and some were both (Hadrosaurus, Iguanodon, Parasaurolophus, and Plateosaurus). Paleontologists
now know that the first dinosaurs were bipedal. The quarapedal habit of some dinosaurs
was a secondary adaptation.
[go back] - Hadrosaurus and Iguanodon belong to an advanced group of ornithischian
dinosaurs. These animals had opposing dental batteries on the upper and lower
jaws which can contain hundreds of self-sharpening teeth. Sideways movement in
both jaws further increased chewing efficiency. These and other chewing adaptations
probably contributed to their success. The adaptations were most advanced in the
hadrosaurs (duck-billed dinosaurs). They were the most diverse and widespread
dinosaur families of the Late Cretaceous.
[go back] - Although
the Hadrosaurus fossil was the most complete dinosaur of its time, it was
still incomplete. Hawkins did the best he could to reconstruct the animal. He
used Leidy's idea of a kangaroo-like stance and created a mount with numerous
kangaroo features. He also modeled the skull, which was essentially unknown, after
the skull of an iguana lizard.
[go back] - Hawkins
mount for the Smithsonian was prominantly displayed in the instutution's pavilion
at the 1876 Centenial Exposition in Philadelphia. This mount was also an immense
success and was later installed in front the new Smithsonian Museum in Washington.
Hawkin's New York venture, however, ended in disaster after a gang of thugs sent
by Boss Tweed destroyed his studio.
[go back]