Vegetarian Dinosaur Comes Home to Arizona’s Glen Canyon Dam

Saturday, March 26 2011 15:14   Arizona
The Bureau of Reclamation and the National Park Service have combined forces to bring a special dinosaur exhibit from the Museum of Northern Arizona to the Carl Hayden Visitor Center at Glen Canyon Dam in Page, Arizona.

Included is the free-standing skeleton of Nothronynchus graffami, a sickle-clawed and feathered dinosaur that was discovered near Big Water, Utah, about 16 miles from the dam and near the shores of Lake Powell. Only three of these have been found in North America. Most of this species have been discovered in Asia.
therizinosaur3Commonly called a Therizinosaur, the dinosaur lives approximately 93 million years ago and was 13 feet tall. It weighed about one ton.

The Therizinosaur was a plant eater with frightening-looking claws that allowed it to both uncover food and to defend itself. The claws measure eight inches and were likely used to tear rotting tree trunks to look for termites to eat.

In order to set up the display at the visitor center, the front double doors had to be disassembled to accommodate the large pelvic and leg bones to be moved into the building. It took nearly an entire day to reassemble each bone which drew the attention of many curious children who were intrigued with the process.

The Therizinosaur's journey through life and death was a fascinating one, according to park rangers.

It roamed the earth during the late Cretaceous period when Glen Canyon was covered by the Cretaceous Western Interior Seaway, a salt water sea. It lived along the shore and also likely grazed on the shoreline vegetation. The Therizinosaur died either while in the water and was carried out to sea on the currents, or it may have been swept out to sea while it was still alive.

It then floated approximately 60 miles until its body settled in the sea bottom where it was unearthed in 2000 in a layer of Tropic Shale. How it managed to cover all that distance without being devoured by fearsome plesiosaurs and sharks is an amazing question, Rangers said.

In addition to the Therizinosaur, the exhibit includes several other fascinating items including a robotic Plesiosaur. According to the National Park Service, Plesiosaur were aquatic reptiles that were ambush predators and terrorized the Cretaceous seas.

The robotic Plesiosaur replicates the swimming movement of the creature. In addition, there are also real plesiosaur bones including the jaw, paddle bones, and teeth of a creature excavated near Lake Powell in the same Tropic Shale rock as the Therizinosaur.

Outside the visitor center, a sculpture of a Pteranodon with a 15-foot wingspan will soon be placed along the Glen Canyon cliff top adjacent to the visitor center. The Pteranodon was a flying reptile with a wing span approaching 25 feet and was a close relative to the dinosaur. It was a meat eater with a diet that was mostly fish that lived 75 to 85 million years ago.

This exhibit will be at Glen Canyon Dam's Carl Hayden Visitor Center through the end of 2011. When visiting the center, be sure to also take the newly renovated tour of Glen Canyon Dam and Powerplant.

Encompassing over 1.2 million acres, Glen Canyon National Recreation Area (NRA) offers unparalleled opportunities for water-based & backcountry recreation.

The recreation area stretches for hundreds of miles from Lees Ferry in Arizona to the Orange Cliffs of southern Utah, encompassing scenic vistas, geologic wonders, and a vast panorama of human history.

For more information, or driving directions, visit the Web site at


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