A cast of the skeleton and skull of Allosaurus jimmadseni as it was discovered and now on exhibit at Dinosaur National Monument in Utah. The original skeleton was molded and cast before it was ...
The newly discovered Opisthiamimus gregori preys on a now-extinct water bug (Morrisonnepa jurassica), while in the background the predatory dinosaur Allosaurus jimmadseni guards its nest.
Allosaurus was the most common large carnivore of the Late Jurassic in North America. It was a smaller predecessor of the Cretaceous Tyrannosaurus. Strong forelimbs with sharp claws, powerful hind ...