Harpers Corner Road Closed for Winter
The Harpers Corner Road is closed for the winter at Plug Hat Picnic Area which is approximately five miles from US Highway 40. The road is tentatively scheduled to open on March 31. More »
Ely Creek Backcountry Campsites Closed
The Ely Creek backcountry campsites located along the Jones Hole Trail have been closed until further notice due to bear activity in the area. More »
About Allosaurus jimmadseni:
Allosaurus jimmadseni is the second species of Allosaurus found at Dinosaur National Monument. The first specimen of A. jimmadseni was found in the monument. It is much rarer than Allosaurus fragilis and they differ in their skeletal details.
Allosaurus, meaning "different reptile," is a theropod (meat eating dinosaur) that probably ate other smaller dinosaurs. Its teeth were serrated like steak knives for cutting flesh. Adults hunted by overpowering their prey, possibly in small groups. Juvenile Allosaurus relied on their longer limb bones that were better adapted to running in order to hunt small vertebrates. Allosaurus was not the largest predator of the time, but its sharp teeth and hook-shaped claws made Allosaurus a nightmare for many creatures of the Jurassic.
Why is Allosaurus jimmadseni a superstar?
Only half of an Allosaurus jimmadseni skull has been found so far. However, the skull separated along its natural midline. Although only the left half of the skull is preserved, it shows both the outside shape and the internal structures, which are rarely seen. The entire braincase is present as well as both ear bones. For the first time in any Allosaurus the wishbone is in place. This Allosaurus jimmadseni is most complete Allosaurus of any species ever found.
Jurassic Fact: A year after the body was discovered, the skull was found thanks to equipment that detects radiation in the bone. Without that equipment, the skull might never have been found.
For more information: visit the Quarry Exhibit Hall to see a cast of Allosaurus jimmadseni as it was found in the ground.
Did You Know?
Dinosaur National Monument's geology is a feast for the mind and the eye. The rock layers, which have been tilted by folding, expose a variety of colors and textures.